fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/cleancache.h>
  42 #include <asm/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/ext4.h>
  56
  57 static struct proc_dir_entry *ext4_proc_root;
  58 static struct kset *ext4_kset;
  59 static struct ext4_lazy_init *ext4_li_info;
  60 static struct mutex ext4_li_mtx;
  61 static struct ext4_features *ext4_feat;
  62
  63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                              unsigned long journal_devnum);
  65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  66 static int ext4_commit_super(struct super_block *sb, int sync);
  67 static void ext4_mark_recovery_complete(struct super_block *sb,
  68                                         struct ext4_super_block *es);
  69 static void ext4_clear_journal_err(struct super_block *sb,
  70                                    struct ext4_super_block *es);
  71 static int ext4_sync_fs(struct super_block *sb, int wait);
  72 static const char *ext4_decode_error(struct super_block *sb, int errno,
  73                                      char nbuf[16]);
  74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  76 static int ext4_unfreeze(struct super_block *sb);
  77 static int ext4_freeze(struct super_block *sb);
  78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  79                        const char *dev_name, void *data);
  80 static inline int ext2_feature_set_ok(struct super_block *sb);
  81 static inline int ext3_feature_set_ok(struct super_block *sb);
  82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  83 static void ext4_destroy_lazyinit_thread(void);
  84 static void ext4_unregister_li_request(struct super_block *sb);
  85 static void ext4_clear_request_list(void);
  86
  87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88 static struct file_system_type ext2_fs_type = {
  89         .owner          = THIS_MODULE,
  90         .name           = "ext2",
  91         .mount          = ext4_mount,
  92         .kill_sb        = kill_block_super,
  93         .fs_flags       = FS_REQUIRES_DEV,
  94 };
  95 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  96 #else
  97 #define IS_EXT2_SB(sb) (0)
  98 #endif
  99
 100
 101 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 102 static struct file_system_type ext3_fs_type = {
 103         .owner          = THIS_MODULE,
 104         .name           = "ext3",
 105         .mount          = ext4_mount,
 106         .kill_sb        = kill_block_super,
 107         .fs_flags       = FS_REQUIRES_DEV,
 108 };
 109 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 110 #else
 111 #define IS_EXT3_SB(sb) (0)
 112 #endif
 113
 114 static int ext4_verify_csum_type(struct super_block *sb,
 115                                  struct ext4_super_block *es)
 116 {
 117         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 118                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 119                 return 1;
 120
 121         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 122 }
 123
 124 static __le32 ext4_superblock_csum(struct super_block *sb,
 125                                    struct ext4_super_block *es)
 126 {
 127         struct ext4_sb_info *sbi = EXT4_SB(sb);
 128         int offset = offsetof(struct ext4_super_block, s_checksum);
 129         __u32 csum;
 130
 131         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 132
 133         return cpu_to_le32(csum);
 134 }
 135
 136 int ext4_superblock_csum_verify(struct super_block *sb,
 137                                 struct ext4_super_block *es)
 138 {
 139         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 140                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 141                 return 1;
 142
 143         return es->s_checksum == ext4_superblock_csum(sb, es);
 144 }
 145
 146 void ext4_superblock_csum_set(struct super_block *sb,
 147                               struct ext4_super_block *es)
 148 {
 149         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 150                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 151                 return;
 152
 153         es->s_checksum = ext4_superblock_csum(sb, es);
 154 }
 155
 156 void *ext4_kvmalloc(size_t size, gfp_t flags)
 157 {
 158         void *ret;
 159
 160         ret = kmalloc(size, flags);
 161         if (!ret)
 162                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 163         return ret;
 164 }
 165
 166 void *ext4_kvzalloc(size_t size, gfp_t flags)
 167 {
 168         void *ret;
 169
 170         ret = kzalloc(size, flags);
 171         if (!ret)
 172                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 173         return ret;
 174 }
 175
 176 void ext4_kvfree(void *ptr)
 177 {
 178         if (is_vmalloc_addr(ptr))
 179                 vfree(ptr);
 180         else
 181                 kfree(ptr);
 182
 183 }
 184
 185 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 186                                struct ext4_group_desc *bg)
 187 {
 188         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 189                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 190                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 191 }
 192
 193 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 194                                struct ext4_group_desc *bg)
 195 {
 196         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 197                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 198                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 199 }
 200
 201 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 202                               struct ext4_group_desc *bg)
 203 {
 204         return le32_to_cpu(bg->bg_inode_table_lo) |
 205                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 206                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 207 }
 208
 209 __u32 ext4_free_group_clusters(struct super_block *sb,
 210                                struct ext4_group_desc *bg)
 211 {
 212         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 213                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 214                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 215 }
 216
 217 __u32 ext4_free_inodes_count(struct super_block *sb,
 218                               struct ext4_group_desc *bg)
 219 {
 220         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 221                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 222                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 223 }
 224
 225 __u32 ext4_used_dirs_count(struct super_block *sb,
 226                               struct ext4_group_desc *bg)
 227 {
 228         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 229                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 230                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 231 }
 232
 233 __u32 ext4_itable_unused_count(struct super_block *sb,
 234                               struct ext4_group_desc *bg)
 235 {
 236         return le16_to_cpu(bg->bg_itable_unused_lo) |
 237                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 238                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 239 }
 240
 241 void ext4_block_bitmap_set(struct super_block *sb,
 242                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 243 {
 244         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 245         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 246                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 247 }
 248
 249 void ext4_inode_bitmap_set(struct super_block *sb,
 250                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 251 {
 252         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 253         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 254                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 255 }
 256
 257 void ext4_inode_table_set(struct super_block *sb,
 258                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 259 {
 260         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 261         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 262                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 263 }
 264
 265 void ext4_free_group_clusters_set(struct super_block *sb,
 266                                   struct ext4_group_desc *bg, __u32 count)
 267 {
 268         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 269         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 270                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 271 }
 272
 273 void ext4_free_inodes_set(struct super_block *sb,
 274                           struct ext4_group_desc *bg, __u32 count)
 275 {
 276         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 277         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 278                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 279 }
 280
 281 void ext4_used_dirs_set(struct super_block *sb,
 282                           struct ext4_group_desc *bg, __u32 count)
 283 {
 284         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 285         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 286                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 287 }
 288
 289 void ext4_itable_unused_set(struct super_block *sb,
 290                           struct ext4_group_desc *bg, __u32 count)
 291 {
 292         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 293         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 294                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 295 }
 296
 297
 298 /* Just increment the non-pointer handle value */
 299 static handle_t *ext4_get_nojournal(void)
 300 {
 301         handle_t *handle = current->journal_info;
 302         unsigned long ref_cnt = (unsigned long)handle;
 303
 304         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
 305
 306         ref_cnt++;
 307         handle = (handle_t *)ref_cnt;
 308
 309         current->journal_info = handle;
 310         return handle;
 311 }
 312
 313
 314 /* Decrement the non-pointer handle value */
 315 static void ext4_put_nojournal(handle_t *handle)
 316 {
 317         unsigned long ref_cnt = (unsigned long)handle;
 318
 319         BUG_ON(ref_cnt == 0);
 320
 321         ref_cnt--;
 322         handle = (handle_t *)ref_cnt;
 323
 324         current->journal_info = handle;
 325 }
 326
 327 /*
 328  * Wrappers for jbd2_journal_start/end.
 329  *
 330  * The only special thing we need to do here is to make sure that all
 331  * journal_end calls result in the superblock being marked dirty, so
 332  * that sync() will call the filesystem's write_super callback if
 333  * appropriate.
 334  */
 335 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 336 {
 337         journal_t *journal;
 338
 339         trace_ext4_journal_start(sb, nblocks, _RET_IP_);
 340         if (sb->s_flags & MS_RDONLY)
 341                 return ERR_PTR(-EROFS);
 342
 343         WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
 344         journal = EXT4_SB(sb)->s_journal;
 345         if (!journal)
 346                 return ext4_get_nojournal();
 347         /*
 348          * Special case here: if the journal has aborted behind our
 349          * backs (eg. EIO in the commit thread), then we still need to
 350          * take the FS itself readonly cleanly.
 351          */
 352         if (is_journal_aborted(journal)) {
 353                 ext4_abort(sb, "Detected aborted journal");
 354                 return ERR_PTR(-EROFS);
 355         }
 356         return jbd2_journal_start(journal, nblocks);
 357 }
 358
 359 /*
 360  * The only special thing we need to do here is to make sure that all
 361  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 362  * that sync() will call the filesystem's write_super callback if
 363  * appropriate.
 364  */
 365 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 366 {
 367         struct super_block *sb;
 368         int err;
 369         int rc;
 370
 371         if (!ext4_handle_valid(handle)) {
 372                 ext4_put_nojournal(handle);
 373                 return 0;
 374         }
 375         sb = handle->h_transaction->t_journal->j_private;
 376         err = handle->h_err;
 377         rc = jbd2_journal_stop(handle);
 378
 379         if (!err)
 380                 err = rc;
 381         if (err)
 382                 __ext4_std_error(sb, where, line, err);
 383         return err;
 384 }
 385
 386 void ext4_journal_abort_handle(const char *caller, unsigned int line,
 387                                const char *err_fn, struct buffer_head *bh,
 388                                handle_t *handle, int err)
 389 {
 390         char nbuf[16];
 391         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 392
 393         BUG_ON(!ext4_handle_valid(handle));
 394
 395         if (bh)
 396                 BUFFER_TRACE(bh, "abort");
 397
 398         if (!handle->h_err)
 399                 handle->h_err = err;
 400
 401         if (is_handle_aborted(handle))
 402                 return;
 403
 404         printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 405                caller, line, errstr, err_fn);
 406
 407         jbd2_journal_abort_handle(handle);
 408 }
 409
 410 static void __save_error_info(struct super_block *sb, const char *func,
 411                             unsigned int line)
 412 {
 413         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 414
 415         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 416         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 417         es->s_last_error_time = cpu_to_le32(get_seconds());
 418         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 419         es->s_last_error_line = cpu_to_le32(line);
 420         if (!es->s_first_error_time) {
 421                 es->s_first_error_time = es->s_last_error_time;
 422                 strncpy(es->s_first_error_func, func,
 423                         sizeof(es->s_first_error_func));
 424                 es->s_first_error_line = cpu_to_le32(line);
 425                 es->s_first_error_ino = es->s_last_error_ino;
 426                 es->s_first_error_block = es->s_last_error_block;
 427         }
 428         /*
 429          * Start the daily error reporting function if it hasn't been
 430          * started already
 431          */
 432         if (!es->s_error_count)
 433                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 434         es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
 435 }
 436
 437 static void save_error_info(struct super_block *sb, const char *func,
 438                             unsigned int line)
 439 {
 440         __save_error_info(sb, func, line);
 441         ext4_commit_super(sb, 1);
 442 }
 443
 444 /*
 445  * The del_gendisk() function uninitializes the disk-specific data
 446  * structures, including the bdi structure, without telling anyone
 447  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 448  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 449  * This is a kludge to prevent these oops until we can put in a proper
 450  * hook in del_gendisk() to inform the VFS and file system layers.
 451  */
 452 static int block_device_ejected(struct super_block *sb)
 453 {
 454         struct inode *bd_inode = sb->s_bdev->bd_inode;
 455         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 456
 457         return bdi->dev == NULL;
 458 }
 459
 460 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 461 {
 462         struct super_block              *sb = journal->j_private;
 463         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 464         int                             error = is_journal_aborted(journal);
 465         struct ext4_journal_cb_entry    *jce, *tmp;
 466
 467         spin_lock(&sbi->s_md_lock);
 468         list_for_each_entry_safe(jce, tmp, &txn->t_private_list, jce_list) {
 469                 list_del_init(&jce->jce_list);
 470                 spin_unlock(&sbi->s_md_lock);
 471                 jce->jce_func(sb, jce, error);
 472                 spin_lock(&sbi->s_md_lock);
 473         }
 474         spin_unlock(&sbi->s_md_lock);
 475 }
 476
 477 /* Deal with the reporting of failure conditions on a filesystem such as
 478  * inconsistencies detected or read IO failures.
 479  *
 480  * On ext2, we can store the error state of the filesystem in the
 481  * superblock.  That is not possible on ext4, because we may have other
 482  * write ordering constraints on the superblock which prevent us from
 483  * writing it out straight away; and given that the journal is about to
 484  * be aborted, we can't rely on the current, or future, transactions to
 485  * write out the superblock safely.
 486  *
 487  * We'll just use the jbd2_journal_abort() error code to record an error in
 488  * the journal instead.  On recovery, the journal will complain about
 489  * that error until we've noted it down and cleared it.
 490  */
 491
 492 static void ext4_handle_error(struct super_block *sb)
 493 {
 494         if (sb->s_flags & MS_RDONLY)
 495                 return;
 496
 497         if (!test_opt(sb, ERRORS_CONT)) {
 498                 journal_t *journal = EXT4_SB(sb)->s_journal;
 499
 500                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 501                 if (journal)
 502                         jbd2_journal_abort(journal, -EIO);
 503         }
 504         if (test_opt(sb, ERRORS_RO)) {
 505                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 506                 sb->s_flags |= MS_RDONLY;
 507         }
 508         if (test_opt(sb, ERRORS_PANIC))
 509                 panic("EXT4-fs (device %s): panic forced after error\n",
 510                         sb->s_id);
 511 }
 512
 513 void __ext4_error(struct super_block *sb, const char *function,
 514                   unsigned int line, const char *fmt, ...)
 515 {
 516         struct va_format vaf;
 517         va_list args;
 518
 519         va_start(args, fmt);
 520         vaf.fmt = fmt;
 521         vaf.va = &args;
 522         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 523                sb->s_id, function, line, current->comm, &vaf);
 524         va_end(args);
 525         save_error_info(sb, function, line);
 526
 527         ext4_handle_error(sb);
 528 }
 529
 530 void ext4_error_inode(struct inode *inode, const char *function,
 531                       unsigned int line, ext4_fsblk_t block,
 532                       const char *fmt, ...)
 533 {
 534         va_list args;
 535         struct va_format vaf;
 536         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 537
 538         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 539         es->s_last_error_block = cpu_to_le64(block);
 540         save_error_info(inode->i_sb, function, line);
 541         va_start(args, fmt);
 542         vaf.fmt = fmt;
 543         vaf.va = &args;
 544         if (block)
 545                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 546                        "inode #%lu: block %llu: comm %s: %pV\n",
 547                        inode->i_sb->s_id, function, line, inode->i_ino,
 548                        block, current->comm, &vaf);
 549         else
 550                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 551                        "inode #%lu: comm %s: %pV\n",
 552                        inode->i_sb->s_id, function, line, inode->i_ino,
 553                        current->comm, &vaf);
 554         va_end(args);
 555
 556         ext4_handle_error(inode->i_sb);
 557 }
 558
 559 void ext4_error_file(struct file *file, const char *function,
 560                      unsigned int line, ext4_fsblk_t block,
 561                      const char *fmt, ...)
 562 {
 563         va_list args;
 564         struct va_format vaf;
 565         struct ext4_super_block *es;
 566         struct inode *inode = file->f_dentry->d_inode;
 567         char pathname[80], *path;
 568
 569         es = EXT4_SB(inode->i_sb)->s_es;
 570         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 571         save_error_info(inode->i_sb, function, line);
 572         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 573         if (IS_ERR(path))
 574                 path = "(unknown)";
 575         va_start(args, fmt);
 576         vaf.fmt = fmt;
 577         vaf.va = &args;
 578         if (block)
 579                 printk(KERN_CRIT
 580                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 581                        "block %llu: comm %s: path %s: %pV\n",
 582                        inode->i_sb->s_id, function, line, inode->i_ino,
 583                        block, current->comm, path, &vaf);
 584         else
 585                 printk(KERN_CRIT
 586                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 587                        "comm %s: path %s: %pV\n",
 588                        inode->i_sb->s_id, function, line, inode->i_ino,
 589                        current->comm, path, &vaf);
 590         va_end(args);
 591
 592         ext4_handle_error(inode->i_sb);
 593 }
 594
 595 static const char *ext4_decode_error(struct super_block *sb, int errno,
 596                                      char nbuf[16])
 597 {
 598         char *errstr = NULL;
 599
 600         switch (errno) {
 601         case -EIO:
 602                 errstr = "IO failure";
 603                 break;
 604         case -ENOMEM:
 605                 errstr = "Out of memory";
 606                 break;
 607         case -EROFS:
 608                 if (!sb || (EXT4_SB(sb)->s_journal &&
 609                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 610                         errstr = "Journal has aborted";
 611                 else
 612                         errstr = "Readonly filesystem";
 613                 break;
 614         default:
 615                 /* If the caller passed in an extra buffer for unknown
 616                  * errors, textualise them now.  Else we just return
 617                  * NULL. */
 618                 if (nbuf) {
 619                         /* Check for truncated error codes... */
 620                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 621                                 errstr = nbuf;
 622                 }
 623                 break;
 624         }
 625
 626         return errstr;
 627 }
 628
 629 /* __ext4_std_error decodes expected errors from journaling functions
 630  * automatically and invokes the appropriate error response.  */
 631
 632 void __ext4_std_error(struct super_block *sb, const char *function,
 633                       unsigned int line, int errno)
 634 {
 635         char nbuf[16];
 636         const char *errstr;
 637
 638         /* Special case: if the error is EROFS, and we're not already
 639          * inside a transaction, then there's really no point in logging
 640          * an error. */
 641         if (errno == -EROFS && journal_current_handle() == NULL &&
 642             (sb->s_flags & MS_RDONLY))
 643                 return;
 644
 645         errstr = ext4_decode_error(sb, errno, nbuf);
 646         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 647                sb->s_id, function, line, errstr);
 648         save_error_info(sb, function, line);
 649
 650         ext4_handle_error(sb);
 651 }
 652
 653 /*
 654  * ext4_abort is a much stronger failure handler than ext4_error.  The
 655  * abort function may be used to deal with unrecoverable failures such
 656  * as journal IO errors or ENOMEM at a critical moment in log management.
 657  *
 658  * We unconditionally force the filesystem into an ABORT|READONLY state,
 659  * unless the error response on the fs has been set to panic in which
 660  * case we take the easy way out and panic immediately.
 661  */
 662
 663 void __ext4_abort(struct super_block *sb, const char *function,
 664                 unsigned int line, const char *fmt, ...)
 665 {
 666         va_list args;
 667
 668         save_error_info(sb, function, line);
 669         va_start(args, fmt);
 670         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 671                function, line);
 672         vprintk(fmt, args);
 673         printk("\n");
 674         va_end(args);
 675
 676         if ((sb->s_flags & MS_RDONLY) == 0) {
 677                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 678                 sb->s_flags |= MS_RDONLY;
 679                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 680                 if (EXT4_SB(sb)->s_journal)
 681                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 682                 save_error_info(sb, function, line);
 683         }
 684         if (test_opt(sb, ERRORS_PANIC))
 685                 panic("EXT4-fs panic from previous error\n");
 686 }
 687
 688 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
 689 {
 690         struct va_format vaf;
 691         va_list args;
 692
 693         va_start(args, fmt);
 694         vaf.fmt = fmt;
 695         vaf.va = &args;
 696         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 697         va_end(args);
 698 }
 699
 700 void __ext4_warning(struct super_block *sb, const char *function,
 701                     unsigned int line, const char *fmt, ...)
 702 {
 703         struct va_format vaf;
 704         va_list args;
 705
 706         va_start(args, fmt);
 707         vaf.fmt = fmt;
 708         vaf.va = &args;
 709         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 710                sb->s_id, function, line, &vaf);
 711         va_end(args);
 712 }
 713
 714 void __ext4_grp_locked_error(const char *function, unsigned int line,
 715                              struct super_block *sb, ext4_group_t grp,
 716                              unsigned long ino, ext4_fsblk_t block,
 717                              const char *fmt, ...)
 718 __releases(bitlock)
 719 __acquires(bitlock)
 720 {
 721         struct va_format vaf;
 722         va_list args;
 723         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 724
 725         es->s_last_error_ino = cpu_to_le32(ino);
 726         es->s_last_error_block = cpu_to_le64(block);
 727         __save_error_info(sb, function, line);
 728
 729         va_start(args, fmt);
 730
 731         vaf.fmt = fmt;
 732         vaf.va = &args;
 733         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 734                sb->s_id, function, line, grp);
 735         if (ino)
 736                 printk(KERN_CONT "inode %lu: ", ino);
 737         if (block)
 738                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
 739         printk(KERN_CONT "%pV\n", &vaf);
 740         va_end(args);
 741
 742         if (test_opt(sb, ERRORS_CONT)) {
 743                 ext4_commit_super(sb, 0);
 744                 return;
 745         }
 746
 747         ext4_unlock_group(sb, grp);
 748         ext4_handle_error(sb);
 749         /*
 750          * We only get here in the ERRORS_RO case; relocking the group
 751          * may be dangerous, but nothing bad will happen since the
 752          * filesystem will have already been marked read/only and the
 753          * journal has been aborted.  We return 1 as a hint to callers
 754          * who might what to use the return value from
 755          * ext4_grp_locked_error() to distinguish between the
 756          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 757          * aggressively from the ext4 function in question, with a
 758          * more appropriate error code.
 759          */
 760         ext4_lock_group(sb, grp);
 761         return;
 762 }
 763
 764 void ext4_update_dynamic_rev(struct super_block *sb)
 765 {
 766         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 767
 768         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 769                 return;
 770
 771         ext4_warning(sb,
 772                      "updating to rev %d because of new feature flag, "
 773                      "running e2fsck is recommended",
 774                      EXT4_DYNAMIC_REV);
 775
 776         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 777         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 778         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 779         /* leave es->s_feature_*compat flags alone */
 780         /* es->s_uuid will be set by e2fsck if empty */
 781
 782         /*
 783          * The rest of the superblock fields should be zero, and if not it
 784          * means they are likely already in use, so leave them alone.  We
 785          * can leave it up to e2fsck to clean up any inconsistencies there.
 786          */
 787 }
 788
 789 /*
 790  * Open the external journal device
 791  */
 792 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 793 {
 794         struct block_device *bdev;
 795         char b[BDEVNAME_SIZE];
 796
 797         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 798         if (IS_ERR(bdev))
 799                 goto fail;
 800         return bdev;
 801
 802 fail:
 803         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 804                         __bdevname(dev, b), PTR_ERR(bdev));
 805         return NULL;
 806 }
 807
 808 /*
 809  * Release the journal device
 810  */
 811 static int ext4_blkdev_put(struct block_device *bdev)
 812 {
 813         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 814 }
 815
 816 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 817 {
 818         struct block_device *bdev;
 819         int ret = -ENODEV;
 820
 821         bdev = sbi->journal_bdev;
 822         if (bdev) {
 823                 ret = ext4_blkdev_put(bdev);
 824                 sbi->journal_bdev = NULL;
 825         }
 826         return ret;
 827 }
 828
 829 static inline struct inode *orphan_list_entry(struct list_head *l)
 830 {
 831         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 832 }
 833
 834 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 835 {
 836         struct list_head *l;
 837
 838         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 839                  le32_to_cpu(sbi->s_es->s_last_orphan));
 840
 841         printk(KERN_ERR "sb_info orphan list:\n");
 842         list_for_each(l, &sbi->s_orphan) {
 843                 struct inode *inode = orphan_list_entry(l);
 844                 printk(KERN_ERR "  "
 845                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 846                        inode->i_sb->s_id, inode->i_ino, inode,
 847                        inode->i_mode, inode->i_nlink,
 848                        NEXT_ORPHAN(inode));
 849         }
 850 }
 851
 852 static void ext4_put_super(struct super_block *sb)
 853 {
 854         struct ext4_sb_info *sbi = EXT4_SB(sb);
 855         struct ext4_super_block *es = sbi->s_es;
 856         int i, err;
 857
 858         ext4_unregister_li_request(sb);
 859         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 860
 861         flush_workqueue(sbi->dio_unwritten_wq);
 862         destroy_workqueue(sbi->dio_unwritten_wq);
 863
 864         if (sbi->s_journal) {
 865                 err = jbd2_journal_destroy(sbi->s_journal);
 866                 sbi->s_journal = NULL;
 867                 if (err < 0)
 868                         ext4_abort(sb, "Couldn't clean up the journal");
 869         }
 870
 871         del_timer(&sbi->s_err_report);
 872         ext4_release_system_zone(sb);
 873         ext4_mb_release(sb);
 874         ext4_ext_release(sb);
 875         ext4_xattr_put_super(sb);
 876
 877         if (!(sb->s_flags & MS_RDONLY)) {
 878                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 879                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 880         }
 881         if (!(sb->s_flags & MS_RDONLY))
 882                 ext4_commit_super(sb, 1);
 883
 884         if (sbi->s_proc) {
 885                 remove_proc_entry("options", sbi->s_proc);
 886                 remove_proc_entry(sb->s_id, ext4_proc_root);
 887         }
 888         kobject_del(&sbi->s_kobj);
 889
 890         for (i = 0; i < sbi->s_gdb_count; i++)
 891                 brelse(sbi->s_group_desc[i]);
 892         ext4_kvfree(sbi->s_group_desc);
 893         ext4_kvfree(sbi->s_flex_groups);
 894         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 895         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 896         percpu_counter_destroy(&sbi->s_dirs_counter);
 897         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 898         brelse(sbi->s_sbh);
 899 #ifdef CONFIG_QUOTA
 900         for (i = 0; i < MAXQUOTAS; i++)
 901                 kfree(sbi->s_qf_names[i]);
 902 #endif
 903
 904         /* Debugging code just in case the in-memory inode orphan list
 905          * isn't empty.  The on-disk one can be non-empty if we've
 906          * detected an error and taken the fs readonly, but the
 907          * in-memory list had better be clean by this point. */
 908         if (!list_empty(&sbi->s_orphan))
 909                 dump_orphan_list(sb, sbi);
 910         J_ASSERT(list_empty(&sbi->s_orphan));
 911
 912         invalidate_bdev(sb->s_bdev);
 913         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 914                 /*
 915                  * Invalidate the journal device's buffers.  We don't want them
 916                  * floating about in memory - the physical journal device may
 917                  * hotswapped, and it breaks the `ro-after' testing code.
 918                  */
 919                 sync_blockdev(sbi->journal_bdev);
 920                 invalidate_bdev(sbi->journal_bdev);
 921                 ext4_blkdev_remove(sbi);
 922         }
 923         if (sbi->s_mmp_tsk)
 924                 kthread_stop(sbi->s_mmp_tsk);
 925         sb->s_fs_info = NULL;
 926         /*
 927          * Now that we are completely done shutting down the
 928          * superblock, we need to actually destroy the kobject.
 929          */
 930         kobject_put(&sbi->s_kobj);
 931         wait_for_completion(&sbi->s_kobj_unregister);
 932         if (sbi->s_chksum_driver)
 933                 crypto_free_shash(sbi->s_chksum_driver);
 934         kfree(sbi->s_blockgroup_lock);
 935         kfree(sbi);
 936 }
 937
 938 static struct kmem_cache *ext4_inode_cachep;
 939
 940 /*
 941  * Called inside transaction, so use GFP_NOFS
 942  */
 943 static struct inode *ext4_alloc_inode(struct super_block *sb)
 944 {
 945         struct ext4_inode_info *ei;
 946
 947         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 948         if (!ei)
 949                 return NULL;
 950
 951         ei->vfs_inode.i_version = 1;
 952         ei->vfs_inode.i_data.writeback_index = 0;
 953         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 954         INIT_LIST_HEAD(&ei->i_prealloc_list);
 955         spin_lock_init(&ei->i_prealloc_lock);
 956         ei->i_reserved_data_blocks = 0;
 957         ei->i_reserved_meta_blocks = 0;
 958         ei->i_allocated_meta_blocks = 0;
 959         ei->i_da_metadata_calc_len = 0;
 960         ei->i_da_metadata_calc_last_lblock = 0;
 961         spin_lock_init(&(ei->i_block_reservation_lock));
 962 #ifdef CONFIG_QUOTA
 963         ei->i_reserved_quota = 0;
 964 #endif
 965         ei->jinode = NULL;
 966         INIT_LIST_HEAD(&ei->i_completed_io_list);
 967         spin_lock_init(&ei->i_completed_io_lock);
 968         ei->cur_aio_dio = NULL;
 969         ei->i_sync_tid = 0;
 970         ei->i_datasync_tid = 0;
 971         atomic_set(&ei->i_ioend_count, 0);
 972         atomic_set(&ei->i_aiodio_unwritten, 0);
 973
 974         return &ei->vfs_inode;
 975 }
 976
 977 static int ext4_drop_inode(struct inode *inode)
 978 {
 979         int drop = generic_drop_inode(inode);
 980
 981         trace_ext4_drop_inode(inode, drop);
 982         return drop;
 983 }
 984
 985 static void ext4_i_callback(struct rcu_head *head)
 986 {
 987         struct inode *inode = container_of(head, struct inode, i_rcu);
 988         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 989 }
 990
 991 static void ext4_destroy_inode(struct inode *inode)
 992 {
 993         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 994                 ext4_msg(inode->i_sb, KERN_ERR,
 995                          "Inode %lu (%p): orphan list check failed!",
 996                          inode->i_ino, EXT4_I(inode));
 997                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 998                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 999                                 true);
1000                 dump_stack();
1001         }
1002         call_rcu(&inode->i_rcu, ext4_i_callback);
1003 }
1004
1005 static void init_once(void *foo)
1006 {
1007         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1008
1009         INIT_LIST_HEAD(&ei->i_orphan);
1010 #ifdef CONFIG_EXT4_FS_XATTR
1011         init_rwsem(&ei->xattr_sem);
1012 #endif
1013         init_rwsem(&ei->i_data_sem);
1014         inode_init_once(&ei->vfs_inode);
1015 }
1016
1017 static int init_inodecache(void)
1018 {
1019         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1020                                              sizeof(struct ext4_inode_info),
1021                                              0, (SLAB_RECLAIM_ACCOUNT|
1022                                                 SLAB_MEM_SPREAD),
1023                                              init_once);
1024         if (ext4_inode_cachep == NULL)
1025                 return -ENOMEM;
1026         return 0;
1027 }
1028
1029 static void destroy_inodecache(void)
1030 {
1031         kmem_cache_destroy(ext4_inode_cachep);
1032 }
1033
1034 void ext4_clear_inode(struct inode *inode)
1035 {
1036         invalidate_inode_buffers(inode);
1037         clear_inode(inode);
1038         dquot_drop(inode);
1039         ext4_discard_preallocations(inode);
1040         if (EXT4_I(inode)->jinode) {
1041                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1042                                                EXT4_I(inode)->jinode);
1043                 jbd2_free_inode(EXT4_I(inode)->jinode);
1044                 EXT4_I(inode)->jinode = NULL;
1045         }
1046 }
1047
1048 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1049                                         u64 ino, u32 generation)
1050 {
1051         struct inode *inode;
1052
1053         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1054                 return ERR_PTR(-ESTALE);
1055         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1056                 return ERR_PTR(-ESTALE);
1057
1058         /* iget isn't really right if the inode is currently unallocated!!
1059          *
1060          * ext4_read_inode will return a bad_inode if the inode had been
1061          * deleted, so we should be safe.
1062          *
1063          * Currently we don't know the generation for parent directory, so
1064          * a generation of 0 means "accept any"
1065          */
1066         inode = ext4_iget(sb, ino);
1067         if (IS_ERR(inode))
1068                 return ERR_CAST(inode);
1069         if (generation && inode->i_generation != generation) {
1070                 iput(inode);
1071                 return ERR_PTR(-ESTALE);
1072         }
1073
1074         return inode;
1075 }
1076
1077 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1078                                         int fh_len, int fh_type)
1079 {
1080         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1081                                     ext4_nfs_get_inode);
1082 }
1083
1084 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1085                                         int fh_len, int fh_type)
1086 {
1087         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1088                                     ext4_nfs_get_inode);
1089 }
1090
1091 /*
1092  * Try to release metadata pages (indirect blocks, directories) which are
1093  * mapped via the block device.  Since these pages could have journal heads
1094  * which would prevent try_to_free_buffers() from freeing them, we must use
1095  * jbd2 layer's try_to_free_buffers() function to release them.
1096  */
1097 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1098                                  gfp_t wait)
1099 {
1100         journal_t *journal = EXT4_SB(sb)->s_journal;
1101
1102         WARN_ON(PageChecked(page));
1103         if (!page_has_buffers(page))
1104                 return 0;
1105         if (journal)
1106                 return jbd2_journal_try_to_free_buffers(journal, page,
1107                                                         wait & ~__GFP_WAIT);
1108         return try_to_free_buffers(page);
1109 }
1110
1111 #ifdef CONFIG_QUOTA
1112 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1113 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1114
1115 static int ext4_write_dquot(struct dquot *dquot);
1116 static int ext4_acquire_dquot(struct dquot *dquot);
1117 static int ext4_release_dquot(struct dquot *dquot);
1118 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1119 static int ext4_write_info(struct super_block *sb, int type);
1120 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1121                          struct path *path);
1122 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1123                                  int format_id);
1124 static int ext4_quota_off(struct super_block *sb, int type);
1125 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1126 static int ext4_quota_on_mount(struct super_block *sb, int type);
1127 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1128                                size_t len, loff_t off);
1129 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1130                                 const char *data, size_t len, loff_t off);
1131 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1132                              unsigned int flags);
1133 static int ext4_enable_quotas(struct super_block *sb);
1134
1135 static const struct dquot_operations ext4_quota_operations = {
1136         .get_reserved_space = ext4_get_reserved_space,
1137         .write_dquot    = ext4_write_dquot,
1138         .acquire_dquot  = ext4_acquire_dquot,
1139         .release_dquot  = ext4_release_dquot,
1140         .mark_dirty     = ext4_mark_dquot_dirty,
1141         .write_info     = ext4_write_info,
1142         .alloc_dquot    = dquot_alloc,
1143         .destroy_dquot  = dquot_destroy,
1144 };
1145
1146 static const struct quotactl_ops ext4_qctl_operations = {
1147         .quota_on       = ext4_quota_on,
1148         .quota_off      = ext4_quota_off,
1149         .quota_sync     = dquot_quota_sync,
1150         .get_info       = dquot_get_dqinfo,
1151         .set_info       = dquot_set_dqinfo,
1152         .get_dqblk      = dquot_get_dqblk,
1153         .set_dqblk      = dquot_set_dqblk
1154 };
1155
1156 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1157         .quota_on_meta  = ext4_quota_on_sysfile,
1158         .quota_off      = ext4_quota_off_sysfile,
1159         .quota_sync     = dquot_quota_sync,
1160         .get_info       = dquot_get_dqinfo,
1161         .set_info       = dquot_set_dqinfo,
1162         .get_dqblk      = dquot_get_dqblk,
1163         .set_dqblk      = dquot_set_dqblk
1164 };
1165 #endif
1166
1167 static const struct super_operations ext4_sops = {
1168         .alloc_inode    = ext4_alloc_inode,
1169         .destroy_inode  = ext4_destroy_inode,
1170         .write_inode    = ext4_write_inode,
1171         .dirty_inode    = ext4_dirty_inode,
1172         .drop_inode     = ext4_drop_inode,
1173         .evict_inode    = ext4_evict_inode,
1174         .put_super      = ext4_put_super,
1175         .sync_fs        = ext4_sync_fs,
1176         .freeze_fs      = ext4_freeze,
1177         .unfreeze_fs    = ext4_unfreeze,
1178         .statfs         = ext4_statfs,
1179         .remount_fs     = ext4_remount,
1180         .show_options   = ext4_show_options,
1181 #ifdef CONFIG_QUOTA
1182         .quota_read     = ext4_quota_read,
1183         .quota_write    = ext4_quota_write,
1184 #endif
1185         .bdev_try_to_free_page = bdev_try_to_free_page,
1186 };
1187
1188 static const struct super_operations ext4_nojournal_sops = {
1189         .alloc_inode    = ext4_alloc_inode,
1190         .destroy_inode  = ext4_destroy_inode,
1191         .write_inode    = ext4_write_inode,
1192         .dirty_inode    = ext4_dirty_inode,
1193         .drop_inode     = ext4_drop_inode,
1194         .evict_inode    = ext4_evict_inode,
1195         .put_super      = ext4_put_super,
1196         .statfs         = ext4_statfs,
1197         .remount_fs     = ext4_remount,
1198         .show_options   = ext4_show_options,
1199 #ifdef CONFIG_QUOTA
1200         .quota_read     = ext4_quota_read,
1201         .quota_write    = ext4_quota_write,
1202 #endif
1203         .bdev_try_to_free_page = bdev_try_to_free_page,
1204 };
1205
1206 static const struct export_operations ext4_export_ops = {
1207         .fh_to_dentry = ext4_fh_to_dentry,
1208         .fh_to_parent = ext4_fh_to_parent,
1209         .get_parent = ext4_get_parent,
1210 };
1211
1212 enum {
1213         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1214         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1215         Opt_nouid32, Opt_debug, Opt_removed,
1216         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1217         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1218         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1219         Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1220         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1221         Opt_data_err_abort, Opt_data_err_ignore,
1222         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1223         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1224         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1225         Opt_usrquota, Opt_grpquota, Opt_i_version,
1226         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1227         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1228         Opt_inode_readahead_blks, Opt_journal_ioprio,
1229         Opt_dioread_nolock, Opt_dioread_lock,
1230         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1231         Opt_max_dir_size_kb,
1232 };
1233
1234 static const match_table_t tokens = {
1235         {Opt_bsd_df, "bsddf"},
1236         {Opt_minix_df, "minixdf"},
1237         {Opt_grpid, "grpid"},
1238         {Opt_grpid, "bsdgroups"},
1239         {Opt_nogrpid, "nogrpid"},
1240         {Opt_nogrpid, "sysvgroups"},
1241         {Opt_resgid, "resgid=%u"},
1242         {Opt_resuid, "resuid=%u"},
1243         {Opt_sb, "sb=%u"},
1244         {Opt_err_cont, "errors=continue"},
1245         {Opt_err_panic, "errors=panic"},
1246         {Opt_err_ro, "errors=remount-ro"},
1247         {Opt_nouid32, "nouid32"},
1248         {Opt_debug, "debug"},
1249         {Opt_removed, "oldalloc"},
1250         {Opt_removed, "orlov"},
1251         {Opt_user_xattr, "user_xattr"},
1252         {Opt_nouser_xattr, "nouser_xattr"},
1253         {Opt_acl, "acl"},
1254         {Opt_noacl, "noacl"},
1255         {Opt_noload, "norecovery"},
1256         {Opt_noload, "noload"},
1257         {Opt_removed, "nobh"},
1258         {Opt_removed, "bh"},
1259         {Opt_commit, "commit=%u"},
1260         {Opt_min_batch_time, "min_batch_time=%u"},
1261         {Opt_max_batch_time, "max_batch_time=%u"},
1262         {Opt_journal_dev, "journal_dev=%u"},
1263         {Opt_journal_checksum, "journal_checksum"},
1264         {Opt_journal_async_commit, "journal_async_commit"},
1265         {Opt_abort, "abort"},
1266         {Opt_data_journal, "data=journal"},
1267         {Opt_data_ordered, "data=ordered"},
1268         {Opt_data_writeback, "data=writeback"},
1269         {Opt_data_err_abort, "data_err=abort"},
1270         {Opt_data_err_ignore, "data_err=ignore"},
1271         {Opt_offusrjquota, "usrjquota="},
1272         {Opt_usrjquota, "usrjquota=%s"},
1273         {Opt_offgrpjquota, "grpjquota="},
1274         {Opt_grpjquota, "grpjquota=%s"},
1275         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1276         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1277         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1278         {Opt_grpquota, "grpquota"},
1279         {Opt_noquota, "noquota"},
1280         {Opt_quota, "quota"},
1281         {Opt_usrquota, "usrquota"},
1282         {Opt_barrier, "barrier=%u"},
1283         {Opt_barrier, "barrier"},
1284         {Opt_nobarrier, "nobarrier"},
1285         {Opt_i_version, "i_version"},
1286         {Opt_stripe, "stripe=%u"},
1287         {Opt_delalloc, "delalloc"},
1288         {Opt_nodelalloc, "nodelalloc"},
1289         {Opt_mblk_io_submit, "mblk_io_submit"},
1290         {Opt_nomblk_io_submit, "nomblk_io_submit"},
1291         {Opt_block_validity, "block_validity"},
1292         {Opt_noblock_validity, "noblock_validity"},
1293         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1294         {Opt_journal_ioprio, "journal_ioprio=%u"},
1295         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1296         {Opt_auto_da_alloc, "auto_da_alloc"},
1297         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1298         {Opt_dioread_nolock, "dioread_nolock"},
1299         {Opt_dioread_lock, "dioread_lock"},
1300         {Opt_discard, "discard"},
1301         {Opt_nodiscard, "nodiscard"},
1302         {Opt_init_itable, "init_itable=%u"},
1303         {Opt_init_itable, "init_itable"},
1304         {Opt_noinit_itable, "noinit_itable"},
1305         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1306         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1307         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1308         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1309         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1310         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1311         {Opt_err, NULL},
1312 };
1313
1314 static ext4_fsblk_t get_sb_block(void **data)
1315 {
1316         ext4_fsblk_t    sb_block;
1317         char            *options = (char *) *data;
1318
1319         if (!options || strncmp(options, "sb=", 3) != 0)
1320                 return 1;       /* Default location */
1321
1322         options += 3;
1323         /* TODO: use simple_strtoll with >32bit ext4 */
1324         sb_block = simple_strtoul(options, &options, 0);
1325         if (*options && *options != ',') {
1326                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1327                        (char *) *data);
1328                 return 1;
1329         }
1330         if (*options == ',')
1331                 options++;
1332         *data = (void *) options;
1333
1334         return sb_block;
1335 }
1336
1337 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1338 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1339         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1340
1341 #ifdef CONFIG_QUOTA
1342 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1343 {
1344         struct ext4_sb_info *sbi = EXT4_SB(sb);
1345         char *qname;
1346
1347         if (sb_any_quota_loaded(sb) &&
1348                 !sbi->s_qf_names[qtype]) {
1349                 ext4_msg(sb, KERN_ERR,
1350                         "Cannot change journaled "
1351                         "quota options when quota turned on");
1352                 return -1;
1353         }
1354         qname = match_strdup(args);
1355         if (!qname) {
1356                 ext4_msg(sb, KERN_ERR,
1357                         "Not enough memory for storing quotafile name");
1358                 return -1;
1359         }
1360         if (sbi->s_qf_names[qtype] &&
1361                 strcmp(sbi->s_qf_names[qtype], qname)) {
1362                 ext4_msg(sb, KERN_ERR,
1363                         "%s quota file already specified", QTYPE2NAME(qtype));
1364                 kfree(qname);
1365                 return -1;
1366         }
1367         sbi->s_qf_names[qtype] = qname;
1368         if (strchr(sbi->s_qf_names[qtype], '/')) {
1369                 ext4_msg(sb, KERN_ERR,
1370                         "quotafile must be on filesystem root");
1371                 kfree(sbi->s_qf_names[qtype]);
1372                 sbi->s_qf_names[qtype] = NULL;
1373                 return -1;
1374         }
1375         set_opt(sb, QUOTA);
1376         return 1;
1377 }
1378
1379 static int clear_qf_name(struct super_block *sb, int qtype)
1380 {
1381
1382         struct ext4_sb_info *sbi = EXT4_SB(sb);
1383
1384         if (sb_any_quota_loaded(sb) &&
1385                 sbi->s_qf_names[qtype]) {
1386                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1387                         " when quota turned on");
1388                 return -1;
1389         }
1390         /*
1391          * The space will be released later when all options are confirmed
1392          * to be correct
1393          */
1394         sbi->s_qf_names[qtype] = NULL;
1395         return 1;
1396 }
1397 #endif
1398
1399 #define MOPT_SET        0x0001
1400 #define MOPT_CLEAR      0x0002
1401 #define MOPT_NOSUPPORT  0x0004
1402 #define MOPT_EXPLICIT   0x0008
1403 #define MOPT_CLEAR_ERR  0x0010
1404 #define MOPT_GTE0       0x0020
1405 #ifdef CONFIG_QUOTA
1406 #define MOPT_Q          0
1407 #define MOPT_QFMT       0x0040
1408 #else
1409 #define MOPT_Q          MOPT_NOSUPPORT
1410 #define MOPT_QFMT       MOPT_NOSUPPORT
1411 #endif
1412 #define MOPT_DATAJ      0x0080
1413
1414 static const struct mount_opts {
1415         int     token;
1416         int     mount_opt;
1417         int     flags;
1418 } ext4_mount_opts[] = {
1419         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1420         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1421         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1422         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1423         {Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
1424         {Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
1425         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1426         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1427         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
1428         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_CLEAR},
1429         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1430         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1431         {Opt_delalloc, EXT4_MOUNT_DELALLOC, MOPT_SET | MOPT_EXPLICIT},
1432         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC, MOPT_CLEAR | MOPT_EXPLICIT},
1433         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM, MOPT_SET},
1434         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1435                                     EXT4_MOUNT_JOURNAL_CHECKSUM), MOPT_SET},
1436         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_SET},
1437         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1438         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1439         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1440         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_SET},
1441         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_CLEAR},
1442         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1443         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1444         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1445         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1446         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1447         {Opt_commit, 0, MOPT_GTE0},
1448         {Opt_max_batch_time, 0, MOPT_GTE0},
1449         {Opt_min_batch_time, 0, MOPT_GTE0},
1450         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1451         {Opt_init_itable, 0, MOPT_GTE0},
1452         {Opt_stripe, 0, MOPT_GTE0},
1453         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
1454         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
1455         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
1456 #ifdef CONFIG_EXT4_FS_XATTR
1457         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1458         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1459 #else
1460         {Opt_user_xattr, 0, MOPT_NOSUPPORT},
1461         {Opt_nouser_xattr, 0, MOPT_NOSUPPORT},
1462 #endif
1463 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1464         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1465         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1466 #else
1467         {Opt_acl, 0, MOPT_NOSUPPORT},
1468         {Opt_noacl, 0, MOPT_NOSUPPORT},
1469 #endif
1470         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1471         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1472         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1473         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1474                                                         MOPT_SET | MOPT_Q},
1475         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1476                                                         MOPT_SET | MOPT_Q},
1477         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1478                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1479         {Opt_usrjquota, 0, MOPT_Q},
1480         {Opt_grpjquota, 0, MOPT_Q},
1481         {Opt_offusrjquota, 0, MOPT_Q},
1482         {Opt_offgrpjquota, 0, MOPT_Q},
1483         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1484         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1485         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1486         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1487         {Opt_err, 0, 0}
1488 };
1489
1490 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1491                             substring_t *args, unsigned long *journal_devnum,
1492                             unsigned int *journal_ioprio, int is_remount)
1493 {
1494         struct ext4_sb_info *sbi = EXT4_SB(sb);
1495         const struct mount_opts *m;
1496         kuid_t uid;
1497         kgid_t gid;
1498         int arg = 0;
1499
1500 #ifdef CONFIG_QUOTA
1501         if (token == Opt_usrjquota)
1502                 return set_qf_name(sb, USRQUOTA, &args[0]);
1503         else if (token == Opt_grpjquota)
1504                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1505         else if (token == Opt_offusrjquota)
1506                 return clear_qf_name(sb, USRQUOTA);
1507         else if (token == Opt_offgrpjquota)
1508                 return clear_qf_name(sb, GRPQUOTA);
1509 #endif
1510         if (args->from && match_int(args, &arg))
1511                 return -1;
1512         switch (token) {
1513         case Opt_noacl:
1514         case Opt_nouser_xattr:
1515                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1516                 break;
1517         case Opt_sb:
1518                 return 1;       /* handled by get_sb_block() */
1519         case Opt_removed:
1520                 ext4_msg(sb, KERN_WARNING,
1521                          "Ignoring removed %s option", opt);
1522                 return 1;
1523         case Opt_resuid:
1524                 uid = make_kuid(current_user_ns(), arg);
1525                 if (!uid_valid(uid)) {
1526                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1527                         return -1;
1528                 }
1529                 sbi->s_resuid = uid;
1530                 return 1;
1531         case Opt_resgid:
1532                 gid = make_kgid(current_user_ns(), arg);
1533                 if (!gid_valid(gid)) {
1534                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1535                         return -1;
1536                 }
1537                 sbi->s_resgid = gid;
1538                 return 1;
1539         case Opt_abort:
1540                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1541                 return 1;
1542         case Opt_i_version:
1543                 sb->s_flags |= MS_I_VERSION;
1544                 return 1;
1545         case Opt_journal_dev:
1546                 if (is_remount) {
1547                         ext4_msg(sb, KERN_ERR,
1548                                  "Cannot specify journal on remount");
1549                         return -1;
1550                 }
1551                 *journal_devnum = arg;
1552                 return 1;
1553         case Opt_journal_ioprio:
1554                 if (arg < 0 || arg > 7)
1555                         return -1;
1556                 *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1557                 return 1;
1558         }
1559
1560         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1561                 if (token != m->token)
1562                         continue;
1563                 if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1564                         return -1;
1565                 if (m->flags & MOPT_EXPLICIT)
1566                         set_opt2(sb, EXPLICIT_DELALLOC);
1567                 if (m->flags & MOPT_CLEAR_ERR)
1568                         clear_opt(sb, ERRORS_MASK);
1569                 if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1570                         ext4_msg(sb, KERN_ERR, "Cannot change quota "
1571                                  "options when quota turned on");
1572                         return -1;
1573                 }
1574
1575                 if (m->flags & MOPT_NOSUPPORT) {
1576                         ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1577                 } else if (token == Opt_commit) {
1578                         if (arg == 0)
1579                                 arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1580                         sbi->s_commit_interval = HZ * arg;
1581                 } else if (token == Opt_max_batch_time) {
1582                         if (arg == 0)
1583                                 arg = EXT4_DEF_MAX_BATCH_TIME;
1584                         sbi->s_max_batch_time = arg;
1585                 } else if (token == Opt_min_batch_time) {
1586                         sbi->s_min_batch_time = arg;
1587                 } else if (token == Opt_inode_readahead_blks) {
1588                         if (arg > (1 << 30))
1589                                 return -1;
1590                         if (arg && !is_power_of_2(arg)) {
1591                                 ext4_msg(sb, KERN_ERR,
1592                                          "EXT4-fs: inode_readahead_blks"
1593                                          " must be a power of 2");
1594                                 return -1;
1595                         }
1596                         sbi->s_inode_readahead_blks = arg;
1597                 } else if (token == Opt_init_itable) {
1598                         set_opt(sb, INIT_INODE_TABLE);
1599                         if (!args->from)
1600                                 arg = EXT4_DEF_LI_WAIT_MULT;
1601                         sbi->s_li_wait_mult = arg;
1602                 } else if (token == Opt_max_dir_size_kb) {
1603                         sbi->s_max_dir_size_kb = arg;
1604                 } else if (token == Opt_stripe) {
1605                         sbi->s_stripe = arg;
1606                 } else if (m->flags & MOPT_DATAJ) {
1607                         if (is_remount) {
1608                                 if (!sbi->s_journal)
1609                                         ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1610                                 else if (test_opt(sb, DATA_FLAGS) !=
1611                                          m->mount_opt) {
1612                                         ext4_msg(sb, KERN_ERR,
1613                                          "Cannot change data mode on remount");
1614                                         return -1;
1615                                 }
1616                         } else {
1617                                 clear_opt(sb, DATA_FLAGS);
1618                                 sbi->s_mount_opt |= m->mount_opt;
1619                         }
1620 #ifdef CONFIG_QUOTA
1621                 } else if (m->flags & MOPT_QFMT) {
1622                         if (sb_any_quota_loaded(sb) &&
1623                             sbi->s_jquota_fmt != m->mount_opt) {
1624                                 ext4_msg(sb, KERN_ERR, "Cannot "
1625                                          "change journaled quota options "
1626                                          "when quota turned on");
1627                                 return -1;
1628                         }
1629                         sbi->s_jquota_fmt = m->mount_opt;
1630 #endif
1631                 } else {
1632                         if (!args->from)
1633                                 arg = 1;
1634                         if (m->flags & MOPT_CLEAR)
1635                                 arg = !arg;
1636                         else if (unlikely(!(m->flags & MOPT_SET))) {
1637                                 ext4_msg(sb, KERN_WARNING,
1638                                          "buggy handling of option %s", opt);
1639                                 WARN_ON(1);
1640                                 return -1;
1641                         }
1642                         if (arg != 0)
1643                                 sbi->s_mount_opt |= m->mount_opt;
1644                         else
1645                                 sbi->s_mount_opt &= ~m->mount_opt;
1646                 }
1647                 return 1;
1648         }
1649         ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1650                  "or missing value", opt);
1651         return -1;
1652 }
1653
1654 static int parse_options(char *options, struct super_block *sb,
1655                          unsigned long *journal_devnum,
1656                          unsigned int *journal_ioprio,
1657                          int is_remount)
1658 {
1659 #ifdef CONFIG_QUOTA
1660         struct ext4_sb_info *sbi = EXT4_SB(sb);
1661 #endif
1662         char *p;
1663         substring_t args[MAX_OPT_ARGS];
1664         int token;
1665
1666         if (!options)
1667                 return 1;
1668
1669         while ((p = strsep(&options, ",")) != NULL) {
1670                 if (!*p)
1671                         continue;
1672                 /*
1673                  * Initialize args struct so we know whether arg was
1674                  * found; some options take optional arguments.
1675                  */
1676                 args[0].to = args[0].from = NULL;
1677                 token = match_token(p, tokens, args);
1678                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1679                                      journal_ioprio, is_remount) < 0)
1680                         return 0;
1681         }
1682 #ifdef CONFIG_QUOTA
1683         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1684                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1685                         clear_opt(sb, USRQUOTA);
1686
1687                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1688                         clear_opt(sb, GRPQUOTA);
1689
1690                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1691                         ext4_msg(sb, KERN_ERR, "old and new quota "
1692                                         "format mixing");
1693                         return 0;
1694                 }
1695
1696                 if (!sbi->s_jquota_fmt) {
1697                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1698                                         "not specified");
1699                         return 0;
1700                 }
1701         } else {
1702                 if (sbi->s_jquota_fmt) {
1703                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1704                                         "specified with no journaling "
1705                                         "enabled");
1706                         return 0;
1707                 }
1708         }
1709 #endif
1710         return 1;
1711 }
1712
1713 static inline void ext4_show_quota_options(struct seq_file *seq,
1714                                            struct super_block *sb)
1715 {
1716 #if defined(CONFIG_QUOTA)
1717         struct ext4_sb_info *sbi = EXT4_SB(sb);
1718
1719         if (sbi->s_jquota_fmt) {
1720                 char *fmtname = "";
1721
1722                 switch (sbi->s_jquota_fmt) {
1723                 case QFMT_VFS_OLD:
1724                         fmtname = "vfsold";
1725                         break;
1726                 case QFMT_VFS_V0:
1727                         fmtname = "vfsv0";
1728                         break;
1729                 case QFMT_VFS_V1:
1730                         fmtname = "vfsv1";
1731                         break;
1732                 }
1733                 seq_printf(seq, ",jqfmt=%s", fmtname);
1734         }
1735
1736         if (sbi->s_qf_names[USRQUOTA])
1737                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1738
1739         if (sbi->s_qf_names[GRPQUOTA])
1740                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1741
1742         if (test_opt(sb, USRQUOTA))
1743                 seq_puts(seq, ",usrquota");
1744
1745         if (test_opt(sb, GRPQUOTA))
1746                 seq_puts(seq, ",grpquota");
1747 #endif
1748 }
1749
1750 static const char *token2str(int token)
1751 {
1752         static const struct match_token *t;
1753
1754         for (t = tokens; t->token != Opt_err; t++)
1755                 if (t->token == token && !strchr(t->pattern, '='))
1756                         break;
1757         return t->pattern;
1758 }
1759
1760 /*
1761  * Show an option if
1762  *  - it's set to a non-default value OR
1763  *  - if the per-sb default is different from the global default
1764  */
1765 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1766                               int nodefs)
1767 {
1768         struct ext4_sb_info *sbi = EXT4_SB(sb);
1769         struct ext4_super_block *es = sbi->s_es;
1770         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1771         const struct mount_opts *m;
1772         char sep = nodefs ? '\n' : ',';
1773
1774 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1775 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1776
1777         if (sbi->s_sb_block != 1)
1778                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1779
1780         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1781                 int want_set = m->flags & MOPT_SET;
1782                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1783                     (m->flags & MOPT_CLEAR_ERR))
1784                         continue;
1785                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1786                         continue; /* skip if same as the default */
1787                 if ((want_set &&
1788                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1789                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1790                         continue; /* select Opt_noFoo vs Opt_Foo */
1791                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1792         }
1793
1794         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1795             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1796                 SEQ_OPTS_PRINT("resuid=%u",
1797                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1798         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1799             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1800                 SEQ_OPTS_PRINT("resgid=%u",
1801                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1802         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1803         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1804                 SEQ_OPTS_PUTS("errors=remount-ro");
1805         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1806                 SEQ_OPTS_PUTS("errors=continue");
1807         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1808                 SEQ_OPTS_PUTS("errors=panic");
1809         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1810                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1811         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1812                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1813         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1814                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1815         if (sb->s_flags & MS_I_VERSION)
1816                 SEQ_OPTS_PUTS("i_version");
1817         if (nodefs || sbi->s_stripe)
1818                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1819         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1820                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1821                         SEQ_OPTS_PUTS("data=journal");
1822                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1823                         SEQ_OPTS_PUTS("data=ordered");
1824                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1825                         SEQ_OPTS_PUTS("data=writeback");
1826         }
1827         if (nodefs ||
1828             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1829                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1830                                sbi->s_inode_readahead_blks);
1831
1832         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1833                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1834                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1835         if (nodefs || sbi->s_max_dir_size_kb)
1836                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1837
1838         ext4_show_quota_options(seq, sb);
1839         return 0;
1840 }
1841
1842 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1843 {
1844         return _ext4_show_options(seq, root->d_sb, 0);
1845 }
1846
1847 static int options_seq_show(struct seq_file *seq, void *offset)
1848 {
1849         struct super_block *sb = seq->private;
1850         int rc;
1851
1852         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1853         rc = _ext4_show_options(seq, sb, 1);
1854         seq_puts(seq, "\n");
1855         return rc;
1856 }
1857
1858 static int options_open_fs(struct inode *inode, struct file *file)
1859 {
1860         return single_open(file, options_seq_show, PDE(inode)->data);
1861 }
1862
1863 static const struct file_operations ext4_seq_options_fops = {
1864         .owner = THIS_MODULE,
1865         .open = options_open_fs,
1866         .read = seq_read,
1867         .llseek = seq_lseek,
1868         .release = single_release,
1869 };
1870
1871 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1872                             int read_only)
1873 {
1874         struct ext4_sb_info *sbi = EXT4_SB(sb);
1875         int res = 0;
1876
1877         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1878                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1879                          "forcing read-only mode");
1880                 res = MS_RDONLY;
1881         }
1882         if (read_only)
1883                 goto done;
1884         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1885                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1886                          "running e2fsck is recommended");
1887         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1888                 ext4_msg(sb, KERN_WARNING,
1889                          "warning: mounting fs with errors, "
1890                          "running e2fsck is recommended");
1891         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1892                  le16_to_cpu(es->s_mnt_count) >=
1893                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1894                 ext4_msg(sb, KERN_WARNING,
1895                          "warning: maximal mount count reached, "
1896                          "running e2fsck is recommended");
1897         else if (le32_to_cpu(es->s_checkinterval) &&
1898                 (le32_to_cpu(es->s_lastcheck) +
1899                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1900                 ext4_msg(sb, KERN_WARNING,
1901                          "warning: checktime reached, "
1902                          "running e2fsck is recommended");
1903         if (!sbi->s_journal)
1904                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1905         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1906                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1907         le16_add_cpu(&es->s_mnt_count, 1);
1908         es->s_mtime = cpu_to_le32(get_seconds());
1909         ext4_update_dynamic_rev(sb);
1910         if (sbi->s_journal)
1911                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1912
1913         ext4_commit_super(sb, 1);
1914 done:
1915         if (test_opt(sb, DEBUG))
1916                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1917                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1918                         sb->s_blocksize,
1919                         sbi->s_groups_count,
1920                         EXT4_BLOCKS_PER_GROUP(sb),
1921                         EXT4_INODES_PER_GROUP(sb),
1922                         sbi->s_mount_opt, sbi->s_mount_opt2);
1923
1924         cleancache_init_fs(sb);
1925         return res;
1926 }
1927
1928 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1929 {
1930         struct ext4_sb_info *sbi = EXT4_SB(sb);
1931         struct flex_groups *new_groups;
1932         int size;
1933
1934         if (!sbi->s_log_groups_per_flex)
1935                 return 0;
1936
1937         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1938         if (size <= sbi->s_flex_groups_allocated)
1939                 return 0;
1940
1941         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1942         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1943         if (!new_groups) {
1944                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1945                          size / (int) sizeof(struct flex_groups));
1946                 return -ENOMEM;
1947         }
1948
1949         if (sbi->s_flex_groups) {
1950                 memcpy(new_groups, sbi->s_flex_groups,
1951                        (sbi->s_flex_groups_allocated *
1952                         sizeof(struct flex_groups)));
1953                 ext4_kvfree(sbi->s_flex_groups);
1954         }
1955         sbi->s_flex_groups = new_groups;
1956         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1957         return 0;
1958 }
1959
1960 static int ext4_fill_flex_info(struct super_block *sb)
1961 {
1962         struct ext4_sb_info *sbi = EXT4_SB(sb);
1963         struct ext4_group_desc *gdp = NULL;
1964         ext4_group_t flex_group;
1965         unsigned int groups_per_flex = 0;
1966         int i, err;
1967
1968         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1969         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1970                 sbi->s_log_groups_per_flex = 0;
1971                 return 1;
1972         }
1973         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1974
1975         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1976         if (err)
1977                 goto failed;
1978
1979         for (i = 0; i < sbi->s_groups_count; i++) {
1980                 gdp = ext4_get_group_desc(sb, i, NULL);
1981
1982                 flex_group = ext4_flex_group(sbi, i);
1983                 atomic_add(ext4_free_inodes_count(sb, gdp),
1984                            &sbi->s_flex_groups[flex_group].free_inodes);
1985                 atomic_add(ext4_free_group_clusters(sb, gdp),
1986                            &sbi->s_flex_groups[flex_group].free_clusters);
1987                 atomic_add(ext4_used_dirs_count(sb, gdp),
1988                            &sbi->s_flex_groups[flex_group].used_dirs);
1989         }
1990
1991         return 1;
1992 failed:
1993         return 0;
1994 }
1995
1996 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1997                                    struct ext4_group_desc *gdp)
1998 {
1999         int offset;
2000         __u16 crc = 0;
2001         __le32 le_group = cpu_to_le32(block_group);
2002
2003         if ((sbi->s_es->s_feature_ro_compat &
2004              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2005                 /* Use new metadata_csum algorithm */
2006                 __u16 old_csum;
2007                 __u32 csum32;
2008
2009                 old_csum = gdp->bg_checksum;
2010                 gdp->bg_checksum = 0;
2011                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2012                                      sizeof(le_group));
2013                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2014                                      sbi->s_desc_size);
2015                 gdp->bg_checksum = old_csum;
2016
2017                 crc = csum32 & 0xFFFF;
2018                 goto out;
2019         }
2020
2021         /* old crc16 code */
2022         offset = offsetof(struct ext4_group_desc, bg_checksum);
2023
2024         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2025         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2026         crc = crc16(crc, (__u8 *)gdp, offset);
2027         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2028         /* for checksum of struct ext4_group_desc do the rest...*/
2029         if ((sbi->s_es->s_feature_incompat &
2030              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2031             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2032                 crc = crc16(crc, (__u8 *)gdp + offset,
2033                             le16_to_cpu(sbi->s_es->s_desc_size) -
2034                                 offset);
2035
2036 out:
2037         return cpu_to_le16(crc);
2038 }
2039
2040 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2041                                 struct ext4_group_desc *gdp)
2042 {
2043         if (ext4_has_group_desc_csum(sb) &&
2044             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2045                                                       block_group, gdp)))
2046                 return 0;
2047
2048         return 1;
2049 }
2050
2051 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2052                               struct ext4_group_desc *gdp)
2053 {
2054         if (!ext4_has_group_desc_csum(sb))
2055                 return;
2056         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2057 }
2058
2059 /* Called at mount-time, super-block is locked */
2060 static int ext4_check_descriptors(struct super_block *sb,
2061                                   ext4_group_t *first_not_zeroed)
2062 {
2063         struct ext4_sb_info *sbi = EXT4_SB(sb);
2064         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2065         ext4_fsblk_t last_block;
2066         ext4_fsblk_t block_bitmap;
2067         ext4_fsblk_t inode_bitmap;
2068         ext4_fsblk_t inode_table;
2069         int flexbg_flag = 0;
2070         ext4_group_t i, grp = sbi->s_groups_count;
2071
2072         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2073                 flexbg_flag = 1;
2074
2075         ext4_debug("Checking group descriptors");
2076
2077         for (i = 0; i < sbi->s_groups_count; i++) {
2078                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2079
2080                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2081                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2082                 else
2083                         last_block = first_block +
2084                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2085
2086                 if ((grp == sbi->s_groups_count) &&
2087                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2088                         grp = i;
2089
2090                 block_bitmap = ext4_block_bitmap(sb, gdp);
2091                 if (block_bitmap < first_block || block_bitmap > last_block) {
2092                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2093                                "Block bitmap for group %u not in group "
2094                                "(block %llu)!", i, block_bitmap);
2095                         return 0;
2096                 }
2097                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2098                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2099                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2100                                "Inode bitmap for group %u not in group "
2101                                "(block %llu)!", i, inode_bitmap);
2102                         return 0;
2103                 }
2104                 inode_table = ext4_inode_table(sb, gdp);
2105                 if (inode_table < first_block ||
2106                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2107                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2108                                "Inode table for group %u not in group "
2109                                "(block %llu)!", i, inode_table);
2110                         return 0;
2111                 }
2112                 ext4_lock_group(sb, i);
2113                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2114                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2115                                  "Checksum for group %u failed (%u!=%u)",
2116                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2117                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2118                         if (!(sb->s_flags & MS_RDONLY)) {
2119                                 ext4_unlock_group(sb, i);
2120                                 return 0;
2121                         }
2122                 }
2123                 ext4_unlock_group(sb, i);
2124                 if (!flexbg_flag)
2125                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2126         }
2127         if (NULL != first_not_zeroed)
2128                 *first_not_zeroed = grp;
2129
2130         ext4_free_blocks_count_set(sbi->s_es,
2131                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2132         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2133         return 1;
2134 }
2135
2136 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2137  * the superblock) which were deleted from all directories, but held open by
2138  * a process at the time of a crash.  We walk the list and try to delete these
2139  * inodes at recovery time (only with a read-write filesystem).
2140  *
2141  * In order to keep the orphan inode chain consistent during traversal (in
2142  * case of crash during recovery), we link each inode into the superblock
2143  * orphan list_head and handle it the same way as an inode deletion during
2144  * normal operation (which journals the operations for us).
2145  *
2146  * We only do an iget() and an iput() on each inode, which is very safe if we
2147  * accidentally point at an in-use or already deleted inode.  The worst that
2148  * can happen in this case is that we get a "bit already cleared" message from
2149  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2150  * e2fsck was run on this filesystem, and it must have already done the orphan
2151  * inode cleanup for us, so we can safely abort without any further action.
2152  */
2153 static void ext4_orphan_cleanup(struct super_block *sb,
2154                                 struct ext4_super_block *es)
2155 {
2156         unsigned int s_flags = sb->s_flags;
2157         int nr_orphans = 0, nr_truncates = 0;
2158 #ifdef CONFIG_QUOTA
2159         int i;
2160 #endif
2161         if (!es->s_last_orphan) {
2162                 jbd_debug(4, "no orphan inodes to clean up\n");
2163                 return;
2164         }
2165
2166         if (bdev_read_only(sb->s_bdev)) {
2167                 ext4_msg(sb, KERN_ERR, "write access "
2168                         "unavailable, skipping orphan cleanup");
2169                 return;
2170         }
2171
2172         /* Check if feature set would not allow a r/w mount */
2173         if (!ext4_feature_set_ok(sb, 0)) {
2174                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2175                          "unknown ROCOMPAT features");
2176                 return;
2177         }
2178
2179         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2180                 if (es->s_last_orphan)
2181                         jbd_debug(1, "Errors on filesystem, "
2182                                   "clearing orphan list.\n");
2183                 es->s_last_orphan = 0;
2184                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2185                 return;
2186         }
2187
2188         if (s_flags & MS_RDONLY) {
2189                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2190                 sb->s_flags &= ~MS_RDONLY;
2191         }
2192 #ifdef CONFIG_QUOTA
2193         /* Needed for iput() to work correctly and not trash data */
2194         sb->s_flags |= MS_ACTIVE;
2195         /* Turn on quotas so that they are updated correctly */
2196         for (i = 0; i < MAXQUOTAS; i++) {
2197                 if (EXT4_SB(sb)->s_qf_names[i]) {
2198                         int ret = ext4_quota_on_mount(sb, i);
2199                         if (ret < 0)
2200                                 ext4_msg(sb, KERN_ERR,
2201                                         "Cannot turn on journaled "
2202                                         "quota: error %d", ret);
2203                 }
2204         }
2205 #endif
2206
2207         while (es->s_last_orphan) {
2208                 struct inode *inode;
2209
2210                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2211                 if (IS_ERR(inode)) {
2212                         es->s_last_orphan = 0;
2213                         break;
2214                 }
2215
2216                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2217                 dquot_initialize(inode);
2218                 if (inode->i_nlink) {
2219                         ext4_msg(sb, KERN_DEBUG,
2220                                 "%s: truncating inode %lu to %lld bytes",
2221                                 __func__, inode->i_ino, inode->i_size);
2222                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2223                                   inode->i_ino, inode->i_size);
2224                         ext4_truncate(inode);
2225                         nr_truncates++;
2226                 } else {
2227                         ext4_msg(sb, KERN_DEBUG,
2228                                 "%s: deleting unreferenced inode %lu",
2229                                 __func__, inode->i_ino);
2230                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2231                                   inode->i_ino);
2232                         nr_orphans++;
2233                 }
2234                 iput(inode);  /* The delete magic happens here! */
2235         }
2236
2237 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2238
2239         if (nr_orphans)
2240                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2241                        PLURAL(nr_orphans));
2242         if (nr_truncates)
2243                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2244                        PLURAL(nr_truncates));
2245 #ifdef CONFIG_QUOTA
2246         /* Turn quotas off */
2247         for (i = 0; i < MAXQUOTAS; i++) {
2248                 if (sb_dqopt(sb)->files[i])
2249                         dquot_quota_off(sb, i);
2250         }
2251 #endif
2252         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2253 }
2254
2255 /*
2256  * Maximal extent format file size.
2257  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2258  * extent format containers, within a sector_t, and within i_blocks
2259  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2260  * so that won't be a limiting factor.
2261  *
2262  * However there is other limiting factor. We do store extents in the form
2263  * of starting block and length, hence the resulting length of the extent
2264  * covering maximum file size must fit into on-disk format containers as
2265  * well. Given that length is always by 1 unit bigger than max unit (because
2266  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2267  *
2268  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2269  */
2270 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2271 {
2272         loff_t res;
2273         loff_t upper_limit = MAX_LFS_FILESIZE;
2274
2275         /* small i_blocks in vfs inode? */
2276         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2277                 /*
2278                  * CONFIG_LBDAF is not enabled implies the inode
2279                  * i_block represent total blocks in 512 bytes
2280                  * 32 == size of vfs inode i_blocks * 8
2281                  */
2282                 upper_limit = (1LL << 32) - 1;
2283
2284                 /* total blocks in file system block size */
2285                 upper_limit >>= (blkbits - 9);
2286                 upper_limit <<= blkbits;
2287         }
2288
2289         /*
2290          * 32-bit extent-start container, ee_block. We lower the maxbytes
2291          * by one fs block, so ee_len can cover the extent of maximum file
2292          * size
2293          */
2294         res = (1LL << 32) - 1;
2295         res <<= blkbits;
2296
2297         /* Sanity check against vm- & vfs- imposed limits */
2298         if (res > upper_limit)
2299                 res = upper_limit;
2300
2301         return res;
2302 }
2303
2304 /*
2305  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2306  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2307  * We need to be 1 filesystem block less than the 2^48 sector limit.
2308  */
2309 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2310 {
2311         loff_t res = EXT4_NDIR_BLOCKS;
2312         int meta_blocks;
2313         loff_t upper_limit;
2314         /* This is calculated to be the largest file size for a dense, block
2315          * mapped file such that the file's total number of 512-byte sectors,
2316          * including data and all indirect blocks, does not exceed (2^48 - 1).
2317          *
2318          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2319          * number of 512-byte sectors of the file.
2320          */
2321
2322         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2323                 /*
2324                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2325                  * the inode i_block field represents total file blocks in
2326                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2327                  */
2328                 upper_limit = (1LL << 32) - 1;
2329
2330                 /* total blocks in file system block size */
2331                 upper_limit >>= (bits - 9);
2332
2333         } else {
2334                 /*
2335                  * We use 48 bit ext4_inode i_blocks
2336                  * With EXT4_HUGE_FILE_FL set the i_blocks
2337                  * represent total number of blocks in
2338                  * file system block size
2339                  */
2340                 upper_limit = (1LL << 48) - 1;
2341
2342         }
2343
2344         /* indirect blocks */
2345         meta_blocks = 1;
2346         /* double indirect blocks */
2347         meta_blocks += 1 + (1LL << (bits-2));
2348         /* tripple indirect blocks */
2349         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2350
2351         upper_limit -= meta_blocks;
2352         upper_limit <<= bits;
2353
2354         res += 1LL << (bits-2);
2355         res += 1LL << (2*(bits-2));
2356         res += 1LL << (3*(bits-2));
2357         res <<= bits;
2358         if (res > upper_limit)
2359                 res = upper_limit;
2360
2361         if (res > MAX_LFS_FILESIZE)
2362                 res = MAX_LFS_FILESIZE;
2363
2364         return res;
2365 }
2366
2367 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2368                                    ext4_fsblk_t logical_sb_block, int nr)
2369 {
2370         struct ext4_sb_info *sbi = EXT4_SB(sb);
2371         ext4_group_t bg, first_meta_bg;
2372         int has_super = 0;
2373
2374         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2375
2376         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2377             nr < first_meta_bg)
2378                 return logical_sb_block + nr + 1;
2379         bg = sbi->s_desc_per_block * nr;
2380         if (ext4_bg_has_super(sb, bg))
2381                 has_super = 1;
2382
2383         return (has_super + ext4_group_first_block_no(sb, bg));
2384 }
2385
2386 /**
2387  * ext4_get_stripe_size: Get the stripe size.
2388  * @sbi: In memory super block info
2389  *
2390  * If we have specified it via mount option, then
2391  * use the mount option value. If the value specified at mount time is
2392  * greater than the blocks per group use the super block value.
2393  * If the super block value is greater than blocks per group return 0.
2394  * Allocator needs it be less than blocks per group.
2395  *
2396  */
2397 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2398 {
2399         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2400         unsigned long stripe_width =
2401                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2402         int ret;
2403
2404         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2405                 ret = sbi->s_stripe;
2406         else if (stripe_width <= sbi->s_blocks_per_group)
2407                 ret = stripe_width;
2408         else if (stride <= sbi->s_blocks_per_group)
2409                 ret = stride;
2410         else
2411                 ret = 0;
2412
2413         /*
2414          * If the stripe width is 1, this makes no sense and
2415          * we set it to 0 to turn off stripe handling code.
2416          */
2417         if (ret <= 1)
2418                 ret = 0;
2419
2420         return ret;
2421 }
2422
2423 /* sysfs supprt */
2424
2425 struct ext4_attr {
2426         struct attribute attr;
2427         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2428         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2429                          const char *, size_t);
2430         int offset;
2431 };
2432
2433 static int parse_strtoul(const char *buf,
2434                 unsigned long max, unsigned long *value)
2435 {
2436         char *endp;
2437
2438         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2439         endp = skip_spaces(endp);
2440         if (*endp || *value > max)
2441                 return -EINVAL;
2442
2443         return 0;
2444 }
2445
2446 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2447                                               struct ext4_sb_info *sbi,
2448                                               char *buf)
2449 {
2450         return snprintf(buf, PAGE_SIZE, "%llu\n",
2451                 (s64) EXT4_C2B(sbi,
2452                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2453 }
2454
2455 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2456                                          struct ext4_sb_info *sbi, char *buf)
2457 {
2458         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2459
2460         if (!sb->s_bdev->bd_part)
2461                 return snprintf(buf, PAGE_SIZE, "0\n");
2462         return snprintf(buf, PAGE_SIZE, "%lu\n",
2463                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2464                          sbi->s_sectors_written_start) >> 1);
2465 }
2466
2467 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2468                                           struct ext4_sb_info *sbi, char *buf)
2469 {
2470         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2471
2472         if (!sb->s_bdev->bd_part)
2473                 return snprintf(buf, PAGE_SIZE, "0\n");
2474         return snprintf(buf, PAGE_SIZE, "%llu\n",
2475                         (unsigned long long)(sbi->s_kbytes_written +
2476                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2477                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2478 }
2479
2480 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2481                                           struct ext4_sb_info *sbi,
2482                                           const char *buf, size_t count)
2483 {
2484         unsigned long t;
2485
2486         if (parse_strtoul(buf, 0x40000000, &t))
2487                 return -EINVAL;
2488
2489         if (t && !is_power_of_2(t))
2490                 return -EINVAL;
2491
2492         sbi->s_inode_readahead_blks = t;
2493         return count;
2494 }
2495
2496 static ssize_t sbi_ui_show(struct ext4_attr *a,
2497                            struct ext4_sb_info *sbi, char *buf)
2498 {
2499         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2500
2501         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2502 }
2503
2504 static ssize_t sbi_ui_store(struct ext4_attr *a,
2505                             struct ext4_sb_info *sbi,
2506                             const char *buf, size_t count)
2507 {
2508         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2509         unsigned long t;
2510
2511         if (parse_strtoul(buf, 0xffffffff, &t))
2512                 return -EINVAL;
2513         *ui = t;
2514         return count;
2515 }
2516
2517 static ssize_t trigger_test_error(struct ext4_attr *a,
2518                                   struct ext4_sb_info *sbi,
2519                                   const char *buf, size_t count)
2520 {
2521         int len = count;
2522
2523         if (!capable(CAP_SYS_ADMIN))
2524                 return -EPERM;
2525
2526         if (len && buf[len-1] == '\n')
2527                 len--;
2528
2529         if (len)
2530                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2531         return count;
2532 }
2533
2534 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2535 static struct ext4_attr ext4_attr_##_name = {                   \
2536         .attr = {.name = __stringify(_name), .mode = _mode },   \
2537         .show   = _show,                                        \
2538         .store  = _store,                                       \
2539         .offset = offsetof(struct ext4_sb_info, _elname),       \
2540 }
2541 #define EXT4_ATTR(name, mode, show, store) \
2542 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2543
2544 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2545 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2546 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2547 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2548         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2549 #define ATTR_LIST(name) &ext4_attr_##name.attr
2550
2551 EXT4_RO_ATTR(delayed_allocation_blocks);
2552 EXT4_RO_ATTR(session_write_kbytes);
2553 EXT4_RO_ATTR(lifetime_write_kbytes);
2554 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2555                  inode_readahead_blks_store, s_inode_readahead_blks);
2556 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2557 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2558 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2559 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2560 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2561 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2562 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2563 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2564 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2565 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2566
2567 static struct attribute *ext4_attrs[] = {
2568         ATTR_LIST(delayed_allocation_blocks),
2569         ATTR_LIST(session_write_kbytes),
2570         ATTR_LIST(lifetime_write_kbytes),
2571         ATTR_LIST(inode_readahead_blks),
2572         ATTR_LIST(inode_goal),
2573         ATTR_LIST(mb_stats),
2574         ATTR_LIST(mb_max_to_scan),
2575         ATTR_LIST(mb_min_to_scan),
2576         ATTR_LIST(mb_order2_req),
2577         ATTR_LIST(mb_stream_req),
2578         ATTR_LIST(mb_group_prealloc),
2579         ATTR_LIST(max_writeback_mb_bump),
2580         ATTR_LIST(extent_max_zeroout_kb),
2581         ATTR_LIST(trigger_fs_error),
2582         NULL,
2583 };
2584
2585 /* Features this copy of ext4 supports */
2586 EXT4_INFO_ATTR(lazy_itable_init);
2587 EXT4_INFO_ATTR(batched_discard);
2588
2589 static struct attribute *ext4_feat_attrs[] = {
2590         ATTR_LIST(lazy_itable_init),
2591         ATTR_LIST(batched_discard),
2592         NULL,
2593 };
2594
2595 static ssize_t ext4_attr_show(struct kobject *kobj,
2596                               struct attribute *attr, char *buf)
2597 {
2598         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2599                                                 s_kobj);
2600         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2601
2602         return a->show ? a->show(a, sbi, buf) : 0;
2603 }
2604
2605 static ssize_t ext4_attr_store(struct kobject *kobj,
2606                                struct attribute *attr,
2607                                const char *buf, size_t len)
2608 {
2609         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2610                                                 s_kobj);
2611         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2612
2613         return a->store ? a->store(a, sbi, buf, len) : 0;
2614 }
2615
2616 static void ext4_sb_release(struct kobject *kobj)
2617 {
2618         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2619                                                 s_kobj);
2620         complete(&sbi->s_kobj_unregister);
2621 }
2622
2623 static const struct sysfs_ops ext4_attr_ops = {
2624         .show   = ext4_attr_show,
2625         .store  = ext4_attr_store,
2626 };
2627
2628 static struct kobj_type ext4_ktype = {
2629         .default_attrs  = ext4_attrs,
2630         .sysfs_ops      = &ext4_attr_ops,
2631         .release        = ext4_sb_release,
2632 };
2633
2634 static void ext4_feat_release(struct kobject *kobj)
2635 {
2636         complete(&ext4_feat->f_kobj_unregister);
2637 }
2638
2639 static struct kobj_type ext4_feat_ktype = {
2640         .default_attrs  = ext4_feat_attrs,
2641         .sysfs_ops      = &ext4_attr_ops,
2642         .release        = ext4_feat_release,
2643 };
2644
2645 /*
2646  * Check whether this filesystem can be mounted based on
2647  * the features present and the RDONLY/RDWR mount requested.
2648  * Returns 1 if this filesystem can be mounted as requested,
2649  * 0 if it cannot be.
2650  */
2651 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2652 {
2653         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2654                 ext4_msg(sb, KERN_ERR,
2655                         "Couldn't mount because of "
2656                         "unsupported optional features (%x)",
2657                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2658                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2659                 return 0;
2660         }
2661
2662         if (readonly)
2663                 return 1;
2664
2665         /* Check that feature set is OK for a read-write mount */
2666         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2667                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2668                          "unsupported optional features (%x)",
2669                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2670                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2671                 return 0;
2672         }
2673         /*
2674          * Large file size enabled file system can only be mounted
2675          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2676          */
2677         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2678                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2679                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2680                                  "cannot be mounted RDWR without "
2681                                  "CONFIG_LBDAF");
2682                         return 0;
2683                 }
2684         }
2685         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2686             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2687                 ext4_msg(sb, KERN_ERR,
2688                          "Can't support bigalloc feature without "
2689                          "extents feature\n");
2690                 return 0;
2691         }
2692
2693 #ifndef CONFIG_QUOTA
2694         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2695             !readonly) {
2696                 ext4_msg(sb, KERN_ERR,
2697                          "Filesystem with quota feature cannot be mounted RDWR "
2698                          "without CONFIG_QUOTA");
2699                 return 0;
2700         }
2701 #endif  /* CONFIG_QUOTA */
2702         return 1;
2703 }
2704
2705 /*
2706  * This function is called once a day if we have errors logged
2707  * on the file system
2708  */
2709 static void print_daily_error_info(unsigned long arg)
2710 {
2711         struct super_block *sb = (struct super_block *) arg;
2712         struct ext4_sb_info *sbi;
2713         struct ext4_super_block *es;
2714
2715         sbi = EXT4_SB(sb);
2716         es = sbi->s_es;
2717
2718         if (es->s_error_count)
2719                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2720                          le32_to_cpu(es->s_error_count));
2721         if (es->s_first_error_time) {
2722                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2723                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2724                        (int) sizeof(es->s_first_error_func),
2725                        es->s_first_error_func,
2726                        le32_to_cpu(es->s_first_error_line));
2727                 if (es->s_first_error_ino)
2728                         printk(": inode %u",
2729                                le32_to_cpu(es->s_first_error_ino));
2730                 if (es->s_first_error_block)
2731                         printk(": block %llu", (unsigned long long)
2732                                le64_to_cpu(es->s_first_error_block));
2733                 printk("\n");
2734         }
2735         if (es->s_last_error_time) {
2736                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2737                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2738                        (int) sizeof(es->s_last_error_func),
2739                        es->s_last_error_func,
2740                        le32_to_cpu(es->s_last_error_line));
2741                 if (es->s_last_error_ino)
2742                         printk(": inode %u",
2743                                le32_to_cpu(es->s_last_error_ino));
2744                 if (es->s_last_error_block)
2745                         printk(": block %llu", (unsigned long long)
2746                                le64_to_cpu(es->s_last_error_block));
2747                 printk("\n");
2748         }
2749         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2750 }
2751
2752 /* Find next suitable group and run ext4_init_inode_table */
2753 static int ext4_run_li_request(struct ext4_li_request *elr)
2754 {
2755         struct ext4_group_desc *gdp = NULL;
2756         ext4_group_t group, ngroups;
2757         struct super_block *sb;
2758         unsigned long timeout = 0;
2759         int ret = 0;
2760
2761         sb = elr->lr_super;
2762         ngroups = EXT4_SB(sb)->s_groups_count;
2763
2764         sb_start_write(sb);
2765         for (group = elr->lr_next_group; group < ngroups; group++) {
2766                 gdp = ext4_get_group_desc(sb, group, NULL);
2767                 if (!gdp) {
2768                         ret = 1;
2769                         break;
2770                 }
2771
2772                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2773                         break;
2774         }
2775
2776         if (group == ngroups)
2777                 ret = 1;
2778
2779         if (!ret) {
2780                 timeout = jiffies;
2781                 ret = ext4_init_inode_table(sb, group,
2782                                             elr->lr_timeout ? 0 : 1);
2783                 if (elr->lr_timeout == 0) {
2784                         timeout = (jiffies - timeout) *
2785                                   elr->lr_sbi->s_li_wait_mult;
2786                         elr->lr_timeout = timeout;
2787                 }
2788                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2789                 elr->lr_next_group = group + 1;
2790         }
2791         sb_end_write(sb);
2792
2793         return ret;
2794 }
2795
2796 /*
2797  * Remove lr_request from the list_request and free the
2798  * request structure. Should be called with li_list_mtx held
2799  */
2800 static void ext4_remove_li_request(struct ext4_li_request *elr)
2801 {
2802         struct ext4_sb_info *sbi;
2803
2804         if (!elr)
2805                 return;
2806
2807         sbi = elr->lr_sbi;
2808
2809         list_del(&elr->lr_request);
2810         sbi->s_li_request = NULL;
2811         kfree(elr);
2812 }
2813
2814 static void ext4_unregister_li_request(struct super_block *sb)
2815 {
2816         mutex_lock(&ext4_li_mtx);
2817         if (!ext4_li_info) {
2818                 mutex_unlock(&ext4_li_mtx);
2819                 return;
2820         }
2821
2822         mutex_lock(&ext4_li_info->li_list_mtx);
2823         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2824         mutex_unlock(&ext4_li_info->li_list_mtx);
2825         mutex_unlock(&ext4_li_mtx);
2826 }
2827
2828 static struct task_struct *ext4_lazyinit_task;
2829
2830 /*
2831  * This is the function where ext4lazyinit thread lives. It walks
2832  * through the request list searching for next scheduled filesystem.
2833  * When such a fs is found, run the lazy initialization request
2834  * (ext4_rn_li_request) and keep track of the time spend in this
2835  * function. Based on that time we compute next schedule time of
2836  * the request. When walking through the list is complete, compute
2837  * next waking time and put itself into sleep.
2838  */
2839 static int ext4_lazyinit_thread(void *arg)
2840 {
2841         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2842         struct list_head *pos, *n;
2843         struct ext4_li_request *elr;
2844         unsigned long next_wakeup, cur;
2845
2846         BUG_ON(NULL == eli);
2847
2848 cont_thread:
2849         while (true) {
2850                 next_wakeup = MAX_JIFFY_OFFSET;
2851
2852                 mutex_lock(&eli->li_list_mtx);
2853                 if (list_empty(&eli->li_request_list)) {
2854                         mutex_unlock(&eli->li_list_mtx);
2855                         goto exit_thread;
2856                 }
2857
2858                 list_for_each_safe(pos, n, &eli->li_request_list) {
2859                         elr = list_entry(pos, struct ext4_li_request,
2860                                          lr_request);
2861
2862                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2863                                 if (ext4_run_li_request(elr) != 0) {
2864                                         /* error, remove the lazy_init job */
2865                                         ext4_remove_li_request(elr);
2866                                         continue;
2867                                 }
2868                         }
2869
2870                         if (time_before(elr->lr_next_sched, next_wakeup))
2871                                 next_wakeup = elr->lr_next_sched;
2872                 }
2873                 mutex_unlock(&eli->li_list_mtx);
2874
2875                 try_to_freeze();
2876
2877                 cur = jiffies;
2878                 if ((time_after_eq(cur, next_wakeup)) ||
2879                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2880                         cond_resched();
2881                         continue;
2882                 }
2883
2884                 schedule_timeout_interruptible(next_wakeup - cur);
2885
2886                 if (kthread_should_stop()) {
2887                         ext4_clear_request_list();
2888                         goto exit_thread;
2889                 }
2890         }
2891
2892 exit_thread:
2893         /*
2894          * It looks like the request list is empty, but we need
2895          * to check it under the li_list_mtx lock, to prevent any
2896          * additions into it, and of course we should lock ext4_li_mtx
2897          * to atomically free the list and ext4_li_info, because at
2898          * this point another ext4 filesystem could be registering
2899          * new one.
2900          */
2901         mutex_lock(&ext4_li_mtx);
2902         mutex_lock(&eli->li_list_mtx);
2903         if (!list_empty(&eli->li_request_list)) {
2904                 mutex_unlock(&eli->li_list_mtx);
2905                 mutex_unlock(&ext4_li_mtx);
2906                 goto cont_thread;
2907         }
2908         mutex_unlock(&eli->li_list_mtx);
2909         kfree(ext4_li_info);
2910         ext4_li_info = NULL;
2911         mutex_unlock(&ext4_li_mtx);
2912
2913         return 0;
2914 }
2915
2916 static void ext4_clear_request_list(void)
2917 {
2918         struct list_head *pos, *n;
2919         struct ext4_li_request *elr;
2920
2921         mutex_lock(&ext4_li_info->li_list_mtx);
2922         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2923                 elr = list_entry(pos, struct ext4_li_request,
2924                                  lr_request);
2925                 ext4_remove_li_request(elr);
2926         }
2927         mutex_unlock(&ext4_li_info->li_list_mtx);
2928 }
2929
2930 static int ext4_run_lazyinit_thread(void)
2931 {
2932         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2933                                          ext4_li_info, "ext4lazyinit");
2934         if (IS_ERR(ext4_lazyinit_task)) {
2935                 int err = PTR_ERR(ext4_lazyinit_task);
2936                 ext4_clear_request_list();
2937                 kfree(ext4_li_info);
2938                 ext4_li_info = NULL;
2939                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2940                                  "initialization thread\n",
2941                                  err);
2942                 return err;
2943         }
2944         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2945         return 0;
2946 }
2947
2948 /*
2949  * Check whether it make sense to run itable init. thread or not.
2950  * If there is at least one uninitialized inode table, return
2951  * corresponding group number, else the loop goes through all
2952  * groups and return total number of groups.
2953  */
2954 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2955 {
2956         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2957         struct ext4_group_desc *gdp = NULL;
2958
2959         for (group = 0; group < ngroups; group++) {
2960                 gdp = ext4_get_group_desc(sb, group, NULL);
2961                 if (!gdp)
2962                         continue;
2963
2964                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2965                         break;
2966         }
2967
2968         return group;
2969 }
2970
2971 static int ext4_li_info_new(void)
2972 {
2973         struct ext4_lazy_init *eli = NULL;
2974
2975         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2976         if (!eli)
2977                 return -ENOMEM;
2978
2979         INIT_LIST_HEAD(&eli->li_request_list);
2980         mutex_init(&eli->li_list_mtx);
2981
2982         eli->li_state |= EXT4_LAZYINIT_QUIT;
2983
2984         ext4_li_info = eli;
2985
2986         return 0;
2987 }
2988
2989 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2990                                             ext4_group_t start)
2991 {
2992         struct ext4_sb_info *sbi = EXT4_SB(sb);
2993         struct ext4_li_request *elr;
2994         unsigned long rnd;
2995
2996         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2997         if (!elr)
2998                 return NULL;
2999
3000         elr->lr_super = sb;
3001         elr->lr_sbi = sbi;
3002         elr->lr_next_group = start;
3003
3004         /*
3005          * Randomize first schedule time of the request to
3006          * spread the inode table initialization requests
3007          * better.
3008          */
3009         get_random_bytes(&rnd, sizeof(rnd));
3010         elr->lr_next_sched = jiffies + (unsigned long)rnd %
3011                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3012
3013         return elr;
3014 }
3015
3016 static int ext4_register_li_request(struct super_block *sb,
3017                                     ext4_group_t first_not_zeroed)
3018 {
3019         struct ext4_sb_info *sbi = EXT4_SB(sb);
3020         struct ext4_li_request *elr;
3021         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3022         int ret = 0;
3023
3024         if (sbi->s_li_request != NULL) {
3025                 /*
3026                  * Reset timeout so it can be computed again, because
3027                  * s_li_wait_mult might have changed.
3028                  */
3029                 sbi->s_li_request->lr_timeout = 0;
3030                 return 0;
3031         }
3032
3033         if (first_not_zeroed == ngroups ||
3034             (sb->s_flags & MS_RDONLY) ||
3035             !test_opt(sb, INIT_INODE_TABLE))
3036                 return 0;
3037
3038         elr = ext4_li_request_new(sb, first_not_zeroed);
3039         if (!elr)
3040                 return -ENOMEM;
3041
3042         mutex_lock(&ext4_li_mtx);
3043
3044         if (NULL == ext4_li_info) {
3045                 ret = ext4_li_info_new();
3046                 if (ret)
3047                         goto out;
3048         }
3049
3050         mutex_lock(&ext4_li_info->li_list_mtx);
3051         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3052         mutex_unlock(&ext4_li_info->li_list_mtx);
3053
3054         sbi->s_li_request = elr;
3055         /*
3056          * set elr to NULL here since it has been inserted to
3057          * the request_list and the removal and free of it is
3058          * handled by ext4_clear_request_list from now on.
3059          */
3060         elr = NULL;
3061
3062         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3063                 ret = ext4_run_lazyinit_thread();
3064                 if (ret)
3065                         goto out;
3066         }
3067 out:
3068         mutex_unlock(&ext4_li_mtx);
3069         if (ret)
3070                 kfree(elr);
3071         return ret;
3072 }
3073
3074 /*
3075  * We do not need to lock anything since this is called on
3076  * module unload.
3077  */
3078 static void ext4_destroy_lazyinit_thread(void)
3079 {
3080         /*
3081          * If thread exited earlier
3082          * there's nothing to be done.
3083          */
3084         if (!ext4_li_info || !ext4_lazyinit_task)
3085                 return;
3086
3087         kthread_stop(ext4_lazyinit_task);
3088 }
3089
3090 static int set_journal_csum_feature_set(struct super_block *sb)
3091 {
3092         int ret = 1;
3093         int compat, incompat;
3094         struct ext4_sb_info *sbi = EXT4_SB(sb);
3095
3096         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3097                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3098                 /* journal checksum v2 */
3099                 compat = 0;
3100                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3101         } else {
3102                 /* journal checksum v1 */
3103                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3104                 incompat = 0;
3105         }
3106
3107         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3108                 ret = jbd2_journal_set_features(sbi->s_journal,
3109                                 compat, 0,
3110                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3111                                 incompat);
3112         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3113                 ret = jbd2_journal_set_features(sbi->s_journal,
3114                                 compat, 0,
3115                                 incompat);
3116                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3117                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3118         } else {
3119                 jbd2_journal_clear_features(sbi->s_journal,
3120                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3121                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3122                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
3123         }
3124
3125         return ret;
3126 }
3127
3128 /*
3129  * Note: calculating the overhead so we can be compatible with
3130  * historical BSD practice is quite difficult in the face of
3131  * clusters/bigalloc.  This is because multiple metadata blocks from
3132  * different block group can end up in the same allocation cluster.
3133  * Calculating the exact overhead in the face of clustered allocation
3134  * requires either O(all block bitmaps) in memory or O(number of block
3135  * groups**2) in time.  We will still calculate the superblock for
3136  * older file systems --- and if we come across with a bigalloc file
3137  * system with zero in s_overhead_clusters the estimate will be close to
3138  * correct especially for very large cluster sizes --- but for newer
3139  * file systems, it's better to calculate this figure once at mkfs
3140  * time, and store it in the superblock.  If the superblock value is
3141  * present (even for non-bigalloc file systems), we will use it.
3142  */
3143 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3144                           char *buf)
3145 {
3146         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3147         struct ext4_group_desc  *gdp;
3148         ext4_fsblk_t            first_block, last_block, b;
3149         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3150         int                     s, j, count = 0;
3151
3152         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3153                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3154                         sbi->s_itb_per_group + 2);
3155
3156         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3157                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3158         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3159         for (i = 0; i < ngroups; i++) {
3160                 gdp = ext4_get_group_desc(sb, i, NULL);
3161                 b = ext4_block_bitmap(sb, gdp);
3162                 if (b >= first_block && b <= last_block) {
3163                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3164                         count++;
3165                 }
3166                 b = ext4_inode_bitmap(sb, gdp);
3167                 if (b >= first_block && b <= last_block) {
3168                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3169                         count++;
3170                 }
3171                 b = ext4_inode_table(sb, gdp);
3172                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3173                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3174                                 int c = EXT4_B2C(sbi, b - first_block);
3175                                 ext4_set_bit(c, buf);
3176                                 count++;
3177                         }
3178                 if (i != grp)
3179                         continue;
3180                 s = 0;
3181                 if (ext4_bg_has_super(sb, grp)) {
3182                         ext4_set_bit(s++, buf);
3183                         count++;
3184                 }
3185                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3186                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3187                         count++;
3188                 }
3189         }
3190         if (!count)
3191                 return 0;
3192         return EXT4_CLUSTERS_PER_GROUP(sb) -
3193                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3194 }
3195
3196 /*
3197  * Compute the overhead and stash it in sbi->s_overhead
3198  */
3199 int ext4_calculate_overhead(struct super_block *sb)
3200 {
3201         struct ext4_sb_info *sbi = EXT4_SB(sb);
3202         struct ext4_super_block *es = sbi->s_es;
3203         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3204         ext4_fsblk_t overhead = 0;
3205         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3206
3207         memset(buf, 0, PAGE_SIZE);
3208         if (!buf)
3209                 return -ENOMEM;
3210
3211         /*
3212          * Compute the overhead (FS structures).  This is constant
3213          * for a given filesystem unless the number of block groups
3214          * changes so we cache the previous value until it does.
3215          */
3216
3217         /*
3218          * All of the blocks before first_data_block are overhead
3219          */
3220         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3221
3222         /*
3223          * Add the overhead found in each block group
3224          */
3225         for (i = 0; i < ngroups; i++) {
3226                 int blks;
3227
3228                 blks = count_overhead(sb, i, buf);
3229                 overhead += blks;
3230                 if (blks)
3231                         memset(buf, 0, PAGE_SIZE);
3232                 cond_resched();
3233         }
3234         sbi->s_overhead = overhead;
3235         smp_wmb();
3236         free_page((unsigned long) buf);
3237         return 0;
3238 }
3239
3240 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3241 {
3242         char *orig_data = kstrdup(data, GFP_KERNEL);
3243         struct buffer_head *bh;
3244         struct ext4_super_block *es = NULL;
3245         struct ext4_sb_info *sbi;
3246         ext4_fsblk_t block;
3247         ext4_fsblk_t sb_block = get_sb_block(&data);
3248         ext4_fsblk_t logical_sb_block;
3249         unsigned long offset = 0;
3250         unsigned long journal_devnum = 0;
3251         unsigned long def_mount_opts;
3252         struct inode *root;
3253         char *cp;
3254         const char *descr;
3255         int ret = -ENOMEM;
3256         int blocksize, clustersize;
3257         unsigned int db_count;
3258         unsigned int i;
3259         int needs_recovery, has_huge_files, has_bigalloc;
3260         __u64 blocks_count;
3261         int err;
3262         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3263         ext4_group_t first_not_zeroed;
3264
3265         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3266         if (!sbi)
3267                 goto out_free_orig;
3268
3269         sbi->s_blockgroup_lock =
3270                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3271         if (!sbi->s_blockgroup_lock) {
3272                 kfree(sbi);
3273                 goto out_free_orig;
3274         }
3275         sb->s_fs_info = sbi;
3276         sbi->s_sb = sb;
3277         sbi->s_mount_opt = 0;
3278         sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
3279         sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
3280         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3281         sbi->s_sb_block = sb_block;
3282         if (sb->s_bdev->bd_part)
3283                 sbi->s_sectors_written_start =
3284                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3285
3286         /* Cleanup superblock name */
3287         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3288                 *cp = '!';
3289
3290         ret = -EINVAL;
3291         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3292         if (!blocksize) {
3293                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3294                 goto out_fail;
3295         }
3296
3297         /*
3298          * The ext4 superblock will not be buffer aligned for other than 1kB
3299          * block sizes.  We need to calculate the offset from buffer start.
3300          */
3301         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3302                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3303                 offset = do_div(logical_sb_block, blocksize);
3304         } else {
3305                 logical_sb_block = sb_block;
3306         }
3307
3308         if (!(bh = sb_bread(sb, logical_sb_block))) {
3309                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3310                 goto out_fail;
3311         }
3312         /*
3313          * Note: s_es must be initialized as soon as possible because
3314          *       some ext4 macro-instructions depend on its value
3315          */
3316         es = (struct ext4_super_block *) (bh->b_data + offset);
3317         sbi->s_es = es;
3318         sb->s_magic = le16_to_cpu(es->s_magic);
3319         if (sb->s_magic != EXT4_SUPER_MAGIC)
3320                 goto cantfind_ext4;
3321         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3322
3323         /* Warn if metadata_csum and gdt_csum are both set. */
3324         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3325                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3326             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3327                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3328                              "redundant flags; please run fsck.");
3329
3330         /* Check for a known checksum algorithm */
3331         if (!ext4_verify_csum_type(sb, es)) {
3332                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3333                          "unknown checksum algorithm.");
3334                 silent = 1;
3335                 goto cantfind_ext4;
3336         }
3337
3338         /* Load the checksum driver */
3339         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3340                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3341                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3342                 if (IS_ERR(sbi->s_chksum_driver)) {
3343                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3344                         ret = PTR_ERR(sbi->s_chksum_driver);
3345                         sbi->s_chksum_driver = NULL;
3346                         goto failed_mount;
3347                 }
3348         }
3349
3350         /* Check superblock checksum */
3351         if (!ext4_superblock_csum_verify(sb, es)) {
3352                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3353                          "invalid superblock checksum.  Run e2fsck?");
3354                 silent = 1;
3355                 goto cantfind_ext4;
3356         }
3357
3358         /* Precompute checksum seed for all metadata */
3359         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3360                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3361                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3362                                                sizeof(es->s_uuid));
3363
3364         /* Set defaults before we parse the mount options */
3365         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3366         set_opt(sb, INIT_INODE_TABLE);
3367         if (def_mount_opts & EXT4_DEFM_DEBUG)
3368                 set_opt(sb, DEBUG);
3369         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3370                 set_opt(sb, GRPID);
3371         if (def_mount_opts & EXT4_DEFM_UID16)
3372                 set_opt(sb, NO_UID32);
3373         /* xattr user namespace & acls are now defaulted on */
3374 #ifdef CONFIG_EXT4_FS_XATTR
3375         set_opt(sb, XATTR_USER);
3376 #endif
3377 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3378         set_opt(sb, POSIX_ACL);
3379 #endif
3380         set_opt(sb, MBLK_IO_SUBMIT);
3381         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3382                 set_opt(sb, JOURNAL_DATA);
3383         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3384                 set_opt(sb, ORDERED_DATA);
3385         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3386                 set_opt(sb, WRITEBACK_DATA);
3387
3388         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3389                 set_opt(sb, ERRORS_PANIC);
3390         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3391                 set_opt(sb, ERRORS_CONT);
3392         else
3393                 set_opt(sb, ERRORS_RO);
3394         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3395                 set_opt(sb, BLOCK_VALIDITY);
3396         if (def_mount_opts & EXT4_DEFM_DISCARD)
3397                 set_opt(sb, DISCARD);
3398
3399         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3400         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3401         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3402         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3403         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3404
3405         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3406                 set_opt(sb, BARRIER);
3407
3408         /*
3409          * enable delayed allocation by default
3410          * Use -o nodelalloc to turn it off
3411          */
3412         if (!IS_EXT3_SB(sb) &&
3413             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3414                 set_opt(sb, DELALLOC);
3415
3416         /*
3417          * set default s_li_wait_mult for lazyinit, for the case there is
3418          * no mount option specified.
3419          */
3420         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3421
3422         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3423                            &journal_devnum, &journal_ioprio, 0)) {
3424                 ext4_msg(sb, KERN_WARNING,
3425                          "failed to parse options in superblock: %s",
3426                          sbi->s_es->s_mount_opts);
3427         }
3428         sbi->s_def_mount_opt = sbi->s_mount_opt;
3429         if (!parse_options((char *) data, sb, &journal_devnum,
3430                            &journal_ioprio, 0))
3431                 goto failed_mount;
3432
3433         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3434                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3435                             "with data=journal disables delayed "
3436                             "allocation and O_DIRECT support!\n");
3437                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3438                         ext4_msg(sb, KERN_ERR, "can't mount with "
3439                                  "both data=journal and delalloc");
3440                         goto failed_mount;
3441                 }
3442                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3443                         ext4_msg(sb, KERN_ERR, "can't mount with "
3444                                  "both data=journal and delalloc");
3445                         goto failed_mount;
3446                 }
3447                 if (test_opt(sb, DELALLOC))
3448                         clear_opt(sb, DELALLOC);
3449         }
3450
3451         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3452         if (test_opt(sb, DIOREAD_NOLOCK)) {
3453                 if (blocksize < PAGE_SIZE) {
3454                         ext4_msg(sb, KERN_ERR, "can't mount with "
3455                                  "dioread_nolock if block size != PAGE_SIZE");
3456                         goto failed_mount;
3457                 }
3458         }
3459
3460         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3461                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3462
3463         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3464             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3465              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3466              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3467                 ext4_msg(sb, KERN_WARNING,
3468                        "feature flags set on rev 0 fs, "
3469                        "running e2fsck is recommended");
3470
3471         if (IS_EXT2_SB(sb)) {
3472                 if (ext2_feature_set_ok(sb))
3473                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3474                                  "using the ext4 subsystem");
3475                 else {
3476                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3477                                  "to feature incompatibilities");
3478                         goto failed_mount;
3479                 }
3480         }
3481
3482         if (IS_EXT3_SB(sb)) {
3483                 if (ext3_feature_set_ok(sb))
3484                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3485                                  "using the ext4 subsystem");
3486                 else {
3487                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3488                                  "to feature incompatibilities");
3489                         goto failed_mount;
3490                 }
3491         }
3492
3493         /*
3494          * Check feature flags regardless of the revision level, since we
3495          * previously didn't change the revision level when setting the flags,
3496          * so there is a chance incompat flags are set on a rev 0 filesystem.
3497          */
3498         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3499                 goto failed_mount;
3500
3501         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3502             blocksize > EXT4_MAX_BLOCK_SIZE) {
3503                 ext4_msg(sb, KERN_ERR,
3504                        "Unsupported filesystem blocksize %d", blocksize);
3505                 goto failed_mount;
3506         }
3507
3508         if (sb->s_blocksize != blocksize) {
3509                 /* Validate the filesystem blocksize */
3510                 if (!sb_set_blocksize(sb, blocksize)) {
3511                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3512                                         blocksize);
3513                         goto failed_mount;
3514                 }
3515
3516                 brelse(bh);
3517                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3518                 offset = do_div(logical_sb_block, blocksize);
3519                 bh = sb_bread(sb, logical_sb_block);
3520                 if (!bh) {
3521                         ext4_msg(sb, KERN_ERR,
3522                                "Can't read superblock on 2nd try");
3523                         goto failed_mount;
3524                 }
3525                 es = (struct ext4_super_block *)(bh->b_data + offset);
3526                 sbi->s_es = es;
3527                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3528                         ext4_msg(sb, KERN_ERR,
3529                                "Magic mismatch, very weird!");
3530                         goto failed_mount;
3531                 }
3532         }
3533
3534         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3535                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3536         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3537                                                       has_huge_files);
3538         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3539
3540         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3541                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3542                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3543         } else {
3544                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3545                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3546                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3547                     (!is_power_of_2(sbi->s_inode_size)) ||
3548                     (sbi->s_inode_size > blocksize)) {
3549                         ext4_msg(sb, KERN_ERR,
3550                                "unsupported inode size: %d",
3551                                sbi->s_inode_size);
3552                         goto failed_mount;
3553                 }
3554                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3555                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3556         }
3557
3558         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3559         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3560                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3561                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3562                     !is_power_of_2(sbi->s_desc_size)) {
3563                         ext4_msg(sb, KERN_ERR,
3564                                "unsupported descriptor size %lu",
3565                                sbi->s_desc_size);
3566                         goto failed_mount;
3567                 }
3568         } else
3569                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3570
3571         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3572         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3573         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3574                 goto cantfind_ext4;
3575
3576         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3577         if (sbi->s_inodes_per_block == 0)
3578                 goto cantfind_ext4;
3579         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3580                                         sbi->s_inodes_per_block;
3581         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3582         sbi->s_sbh = bh;
3583         sbi->s_mount_state = le16_to_cpu(es->s_state);
3584         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3585         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3586
3587         for (i = 0; i < 4; i++)
3588                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3589         sbi->s_def_hash_version = es->s_def_hash_version;
3590         i = le32_to_cpu(es->s_flags);
3591         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3592                 sbi->s_hash_unsigned = 3;
3593         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3594 #ifdef __CHAR_UNSIGNED__
3595                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3596                 sbi->s_hash_unsigned = 3;
3597 #else
3598                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3599 #endif
3600         }
3601
3602         /* Handle clustersize */
3603         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3604         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3605                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3606         if (has_bigalloc) {
3607                 if (clustersize < blocksize) {
3608                         ext4_msg(sb, KERN_ERR,
3609                                  "cluster size (%d) smaller than "
3610                                  "block size (%d)", clustersize, blocksize);
3611                         goto failed_mount;
3612                 }
3613                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3614                         le32_to_cpu(es->s_log_block_size);
3615                 sbi->s_clusters_per_group =
3616                         le32_to_cpu(es->s_clusters_per_group);
3617                 if (sbi->s_clusters_per_group > blocksize * 8) {
3618                         ext4_msg(sb, KERN_ERR,
3619                                  "#clusters per group too big: %lu",
3620                                  sbi->s_clusters_per_group);
3621                         goto failed_mount;
3622                 }
3623                 if (sbi->s_blocks_per_group !=
3624                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3625                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3626                                  "clusters per group (%lu) inconsistent",
3627                                  sbi->s_blocks_per_group,
3628                                  sbi->s_clusters_per_group);
3629                         goto failed_mount;
3630                 }
3631         } else {
3632                 if (clustersize != blocksize) {
3633                         ext4_warning(sb, "fragment/cluster size (%d) != "
3634                                      "block size (%d)", clustersize,
3635                                      blocksize);
3636                         clustersize = blocksize;
3637                 }
3638                 if (sbi->s_blocks_per_group > blocksize * 8) {
3639                         ext4_msg(sb, KERN_ERR,
3640                                  "#blocks per group too big: %lu",
3641                                  sbi->s_blocks_per_group);
3642                         goto failed_mount;
3643                 }
3644                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3645                 sbi->s_cluster_bits = 0;
3646         }
3647         sbi->s_cluster_ratio = clustersize / blocksize;
3648
3649         if (sbi->s_inodes_per_group > blocksize * 8) {
3650                 ext4_msg(sb, KERN_ERR,
3651                        "#inodes per group too big: %lu",
3652                        sbi->s_inodes_per_group);
3653                 goto failed_mount;
3654         }
3655
3656         /*
3657          * Test whether we have more sectors than will fit in sector_t,
3658          * and whether the max offset is addressable by the page cache.
3659          */
3660         err = generic_check_addressable(sb->s_blocksize_bits,
3661                                         ext4_blocks_count(es));
3662         if (err) {
3663                 ext4_msg(sb, KERN_ERR, "filesystem"
3664                          " too large to mount safely on this system");
3665                 if (sizeof(sector_t) < 8)
3666                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3667                 ret = err;
3668                 goto failed_mount;
3669         }
3670
3671         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3672                 goto cantfind_ext4;
3673
3674         /* check blocks count against device size */
3675         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3676         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3677                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3678                        "exceeds size of device (%llu blocks)",
3679                        ext4_blocks_count(es), blocks_count);
3680                 goto failed_mount;
3681         }
3682
3683         /*
3684          * It makes no sense for the first data block to be beyond the end
3685          * of the filesystem.
3686          */
3687         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3688                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3689                          "block %u is beyond end of filesystem (%llu)",
3690                          le32_to_cpu(es->s_first_data_block),
3691                          ext4_blocks_count(es));
3692                 goto failed_mount;
3693         }
3694         blocks_count = (ext4_blocks_count(es) -
3695                         le32_to_cpu(es->s_first_data_block) +
3696                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3697         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3698         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3699                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3700                        "(block count %llu, first data block %u, "
3701                        "blocks per group %lu)", sbi->s_groups_count,
3702                        ext4_blocks_count(es),
3703                        le32_to_cpu(es->s_first_data_block),
3704                        EXT4_BLOCKS_PER_GROUP(sb));
3705                 goto failed_mount;
3706         }
3707         sbi->s_groups_count = blocks_count;
3708         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3709                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3710         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3711                    EXT4_DESC_PER_BLOCK(sb);
3712         sbi->s_group_desc = ext4_kvmalloc(db_count *
3713                                           sizeof(struct buffer_head *),
3714                                           GFP_KERNEL);
3715         if (sbi->s_group_desc == NULL) {
3716                 ext4_msg(sb, KERN_ERR, "not enough memory");
3717                 ret = -ENOMEM;
3718                 goto failed_mount;
3719         }
3720
3721         if (ext4_proc_root)
3722                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3723
3724         if (sbi->s_proc)
3725                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3726                                  &ext4_seq_options_fops, sb);
3727
3728         bgl_lock_init(sbi->s_blockgroup_lock);
3729
3730         for (i = 0; i < db_count; i++) {
3731                 block = descriptor_loc(sb, logical_sb_block, i);
3732                 sbi->s_group_desc[i] = sb_bread(sb, block);
3733                 if (!sbi->s_group_desc[i]) {
3734                         ext4_msg(sb, KERN_ERR,
3735                                "can't read group descriptor %d", i);
3736                         db_count = i;
3737                         goto failed_mount2;
3738                 }
3739         }
3740         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3741                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3742                 goto failed_mount2;
3743         }
3744         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3745                 if (!ext4_fill_flex_info(sb)) {
3746                         ext4_msg(sb, KERN_ERR,
3747                                "unable to initialize "
3748                                "flex_bg meta info!");
3749                         goto failed_mount2;
3750                 }
3751
3752         sbi->s_gdb_count = db_count;
3753         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3754         spin_lock_init(&sbi->s_next_gen_lock);
3755
3756         init_timer(&sbi->s_err_report);
3757         sbi->s_err_report.function = print_daily_error_info;
3758         sbi->s_err_report.data = (unsigned long) sb;
3759
3760         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3761                         ext4_count_free_clusters(sb));
3762         if (!err) {
3763                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3764                                 ext4_count_free_inodes(sb));
3765         }
3766         if (!err) {
3767                 err = percpu_counter_init(&sbi->s_dirs_counter,
3768                                 ext4_count_dirs(sb));
3769         }
3770         if (!err) {
3771                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3772         }
3773         if (err) {
3774                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3775                 ret = err;
3776                 goto failed_mount3;
3777         }
3778
3779         sbi->s_stripe = ext4_get_stripe_size(sbi);
3780         sbi->s_max_writeback_mb_bump = 128;
3781         sbi->s_extent_max_zeroout_kb = 32;
3782
3783         /*
3784          * set up enough so that it can read an inode
3785          */
3786         if (!test_opt(sb, NOLOAD) &&
3787             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3788                 sb->s_op = &ext4_sops;
3789         else
3790                 sb->s_op = &ext4_nojournal_sops;
3791         sb->s_export_op = &ext4_export_ops;
3792         sb->s_xattr = ext4_xattr_handlers;
3793 #ifdef CONFIG_QUOTA
3794         sb->s_qcop = &ext4_qctl_operations;
3795         sb->dq_op = &ext4_quota_operations;
3796
3797         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
3798                 /* Use qctl operations for hidden quota files. */
3799                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3800         }
3801 #endif
3802         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3803
3804         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3805         mutex_init(&sbi->s_orphan_lock);
3806         sbi->s_resize_flags = 0;
3807
3808         sb->s_root = NULL;
3809
3810         needs_recovery = (es->s_last_orphan != 0 ||
3811                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3812                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3813
3814         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3815             !(sb->s_flags & MS_RDONLY))
3816                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3817                         goto failed_mount3;
3818
3819         /*
3820          * The first inode we look at is the journal inode.  Don't try
3821          * root first: it may be modified in the journal!
3822          */
3823         if (!test_opt(sb, NOLOAD) &&
3824             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3825                 if (ext4_load_journal(sb, es, journal_devnum))
3826                         goto failed_mount3;
3827         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3828               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3829                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3830                        "suppressed and not mounted read-only");
3831                 goto failed_mount_wq;
3832         } else {
3833                 clear_opt(sb, DATA_FLAGS);
3834                 sbi->s_journal = NULL;
3835                 needs_recovery = 0;
3836                 goto no_journal;
3837         }
3838
3839         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3840             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3841                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3842                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3843                 goto failed_mount_wq;
3844         }
3845
3846         if (!set_journal_csum_feature_set(sb)) {
3847                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3848                          "feature set");
3849                 goto failed_mount_wq;
3850         }
3851
3852         /* We have now updated the journal if required, so we can
3853          * validate the data journaling mode. */
3854         switch (test_opt(sb, DATA_FLAGS)) {
3855         case 0:
3856                 /* No mode set, assume a default based on the journal
3857                  * capabilities: ORDERED_DATA if the journal can
3858                  * cope, else JOURNAL_DATA
3859                  */
3860                 if (jbd2_journal_check_available_features
3861                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3862                         set_opt(sb, ORDERED_DATA);
3863                 else
3864                         set_opt(sb, JOURNAL_DATA);
3865                 break;
3866
3867         case EXT4_MOUNT_ORDERED_DATA:
3868         case EXT4_MOUNT_WRITEBACK_DATA:
3869                 if (!jbd2_journal_check_available_features
3870                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3871                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3872                                "requested data journaling mode");
3873                         goto failed_mount_wq;
3874                 }
3875         default:
3876                 break;
3877         }
3878         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3879
3880         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3881
3882         /*
3883          * The journal may have updated the bg summary counts, so we
3884          * need to update the global counters.
3885          */
3886         percpu_counter_set(&sbi->s_freeclusters_counter,
3887                            ext4_count_free_clusters(sb));
3888         percpu_counter_set(&sbi->s_freeinodes_counter,
3889                            ext4_count_free_inodes(sb));
3890         percpu_counter_set(&sbi->s_dirs_counter,
3891                            ext4_count_dirs(sb));
3892         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3893
3894 no_journal:
3895         /*
3896          * Get the # of file system overhead blocks from the
3897          * superblock if present.
3898          */
3899         if (es->s_overhead_clusters)
3900                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3901         else {
3902                 ret = ext4_calculate_overhead(sb);
3903                 if (ret)
3904                         goto failed_mount_wq;
3905         }
3906
3907         /*
3908          * The maximum number of concurrent works can be high and
3909          * concurrency isn't really necessary.  Limit it to 1.
3910          */
3911         EXT4_SB(sb)->dio_unwritten_wq =
3912                 alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3913         if (!EXT4_SB(sb)->dio_unwritten_wq) {
3914                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3915                 goto failed_mount_wq;
3916         }
3917
3918         /*
3919          * The jbd2_journal_load will have done any necessary log recovery,
3920          * so we can safely mount the rest of the filesystem now.
3921          */
3922
3923         root = ext4_iget(sb, EXT4_ROOT_INO);
3924         if (IS_ERR(root)) {
3925                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3926                 ret = PTR_ERR(root);
3927                 root = NULL;
3928                 goto failed_mount4;
3929         }
3930         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3931                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3932                 iput(root);
3933                 goto failed_mount4;
3934         }
3935         sb->s_root = d_make_root(root);
3936         if (!sb->s_root) {
3937                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3938                 ret = -ENOMEM;
3939                 goto failed_mount4;
3940         }
3941
3942         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3943                 sb->s_flags |= MS_RDONLY;
3944
3945         /* determine the minimum size of new large inodes, if present */
3946         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3947                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3948                                                      EXT4_GOOD_OLD_INODE_SIZE;
3949                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3950                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3951                         if (sbi->s_want_extra_isize <
3952                             le16_to_cpu(es->s_want_extra_isize))
3953                                 sbi->s_want_extra_isize =
3954                                         le16_to_cpu(es->s_want_extra_isize);
3955                         if (sbi->s_want_extra_isize <
3956                             le16_to_cpu(es->s_min_extra_isize))
3957                                 sbi->s_want_extra_isize =
3958                                         le16_to_cpu(es->s_min_extra_isize);
3959                 }
3960         }
3961         /* Check if enough inode space is available */
3962         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3963                                                         sbi->s_inode_size) {
3964                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3965                                                        EXT4_GOOD_OLD_INODE_SIZE;
3966                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3967                          "available");
3968         }
3969
3970         err = ext4_setup_system_zone(sb);
3971         if (err) {
3972                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3973                          "zone (%d)", err);
3974                 goto failed_mount4a;
3975         }
3976
3977         ext4_ext_init(sb);
3978         err = ext4_mb_init(sb);
3979         if (err) {
3980                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3981                          err);
3982                 goto failed_mount5;
3983         }
3984
3985         err = ext4_register_li_request(sb, first_not_zeroed);
3986         if (err)
3987                 goto failed_mount6;
3988
3989         sbi->s_kobj.kset = ext4_kset;
3990         init_completion(&sbi->s_kobj_unregister);
3991         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3992                                    "%s", sb->s_id);
3993         if (err)
3994                 goto failed_mount7;
3995
3996         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3997         ext4_orphan_cleanup(sb, es);
3998         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3999         if (needs_recovery) {
4000                 ext4_msg(sb, KERN_INFO, "recovery complete");
4001                 ext4_mark_recovery_complete(sb, es);
4002         }
4003         if (EXT4_SB(sb)->s_journal) {
4004                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4005                         descr = " journalled data mode";
4006                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4007                         descr = " ordered data mode";
4008                 else
4009                         descr = " writeback data mode";
4010         } else
4011                 descr = "out journal";
4012
4013 #ifdef CONFIG_QUOTA
4014         /* Enable quota usage during mount. */
4015         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4016             !(sb->s_flags & MS_RDONLY)) {
4017                 ret = ext4_enable_quotas(sb);
4018                 if (ret)
4019                         goto failed_mount7;
4020         }
4021 #endif  /* CONFIG_QUOTA */
4022
4023         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4024                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4025                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4026
4027         if (es->s_error_count)
4028                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4029
4030         kfree(orig_data);
4031         return 0;
4032
4033 cantfind_ext4:
4034         if (!silent)
4035                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4036         goto failed_mount;
4037
4038 failed_mount7:
4039         ext4_unregister_li_request(sb);
4040 failed_mount6:
4041         ext4_mb_release(sb);
4042 failed_mount5:
4043         ext4_ext_release(sb);
4044         ext4_release_system_zone(sb);
4045 failed_mount4a:
4046         dput(sb->s_root);
4047         sb->s_root = NULL;
4048 failed_mount4:
4049         ext4_msg(sb, KERN_ERR, "mount failed");
4050         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4051 failed_mount_wq:
4052         if (sbi->s_journal) {
4053                 jbd2_journal_destroy(sbi->s_journal);
4054                 sbi->s_journal = NULL;
4055         }
4056 failed_mount3:
4057         del_timer(&sbi->s_err_report);
4058         if (sbi->s_flex_groups)
4059                 ext4_kvfree(sbi->s_flex_groups);
4060         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4061         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4062         percpu_counter_destroy(&sbi->s_dirs_counter);
4063         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4064         if (sbi->s_mmp_tsk)
4065                 kthread_stop(sbi->s_mmp_tsk);
4066 failed_mount2:
4067         for (i = 0; i < db_count; i++)
4068                 brelse(sbi->s_group_desc[i]);
4069         ext4_kvfree(sbi->s_group_desc);
4070 failed_mount:
4071         if (sbi->s_chksum_driver)
4072                 crypto_free_shash(sbi->s_chksum_driver);
4073         if (sbi->s_proc) {
4074                 remove_proc_entry("options", sbi->s_proc);
4075                 remove_proc_entry(sb->s_id, ext4_proc_root);
4076         }
4077 #ifdef CONFIG_QUOTA
4078         for (i = 0; i < MAXQUOTAS; i++)
4079                 kfree(sbi->s_qf_names[i]);
4080 #endif
4081         ext4_blkdev_remove(sbi);
4082         brelse(bh);
4083 out_fail:
4084         sb->s_fs_info = NULL;
4085         kfree(sbi->s_blockgroup_lock);
4086         kfree(sbi);
4087 out_free_orig:
4088         kfree(orig_data);
4089         return ret;
4090 }
4091
4092 /*
4093  * Setup any per-fs journal parameters now.  We'll do this both on
4094  * initial mount, once the journal has been initialised but before we've
4095  * done any recovery; and again on any subsequent remount.
4096  */
4097 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4098 {
4099         struct ext4_sb_info *sbi = EXT4_SB(sb);
4100
4101         journal->j_commit_interval = sbi->s_commit_interval;
4102         journal->j_min_batch_time = sbi->s_min_batch_time;
4103         journal->j_max_batch_time = sbi->s_max_batch_time;
4104
4105         write_lock(&journal->j_state_lock);
4106         if (test_opt(sb, BARRIER))
4107                 journal->j_flags |= JBD2_BARRIER;
4108         else
4109                 journal->j_flags &= ~JBD2_BARRIER;
4110         if (test_opt(sb, DATA_ERR_ABORT))
4111                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4112         else
4113                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4114         write_unlock(&journal->j_state_lock);
4115 }
4116
4117 static journal_t *ext4_get_journal(struct super_block *sb,
4118                                    unsigned int journal_inum)
4119 {
4120         struct inode *journal_inode;
4121         journal_t *journal;
4122
4123         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4124
4125         /* First, test for the existence of a valid inode on disk.  Bad
4126          * things happen if we iget() an unused inode, as the subsequent
4127          * iput() will try to delete it. */
4128
4129         journal_inode = ext4_iget(sb, journal_inum);
4130         if (IS_ERR(journal_inode)) {
4131                 ext4_msg(sb, KERN_ERR, "no journal found");
4132                 return NULL;
4133         }
4134         if (!journal_inode->i_nlink) {
4135                 make_bad_inode(journal_inode);
4136                 iput(journal_inode);
4137                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4138                 return NULL;
4139         }
4140
4141         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4142                   journal_inode, journal_inode->i_size);
4143         if (!S_ISREG(journal_inode->i_mode)) {
4144                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4145                 iput(journal_inode);
4146                 return NULL;
4147         }
4148
4149         journal = jbd2_journal_init_inode(journal_inode);
4150         if (!journal) {
4151                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4152                 iput(journal_inode);
4153                 return NULL;
4154         }
4155         journal->j_private = sb;
4156         ext4_init_journal_params(sb, journal);
4157         return journal;
4158 }
4159
4160 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4161                                        dev_t j_dev)
4162 {
4163         struct buffer_head *bh;
4164         journal_t *journal;
4165         ext4_fsblk_t start;
4166         ext4_fsblk_t len;
4167         int hblock, blocksize;
4168         ext4_fsblk_t sb_block;
4169         unsigned long offset;
4170         struct ext4_super_block *es;
4171         struct block_device *bdev;
4172
4173         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4174
4175         bdev = ext4_blkdev_get(j_dev, sb);
4176         if (bdev == NULL)
4177                 return NULL;
4178
4179         blocksize = sb->s_blocksize;
4180         hblock = bdev_logical_block_size(bdev);
4181         if (blocksize < hblock) {
4182                 ext4_msg(sb, KERN_ERR,
4183                         "blocksize too small for journal device");
4184                 goto out_bdev;
4185         }
4186
4187         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4188         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4189         set_blocksize(bdev, blocksize);
4190         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4191                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4192                        "external journal");
4193                 goto out_bdev;
4194         }
4195
4196         es = (struct ext4_super_block *) (bh->b_data + offset);
4197         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4198             !(le32_to_cpu(es->s_feature_incompat) &
4199               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4200                 ext4_msg(sb, KERN_ERR, "external journal has "
4201                                         "bad superblock");
4202                 brelse(bh);
4203                 goto out_bdev;
4204         }
4205
4206         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4207                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4208                 brelse(bh);
4209                 goto out_bdev;
4210         }
4211
4212         len = ext4_blocks_count(es);
4213         start = sb_block + 1;
4214         brelse(bh);     /* we're done with the superblock */
4215
4216         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4217                                         start, len, blocksize);
4218         if (!journal) {
4219                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4220                 goto out_bdev;
4221         }
4222         journal->j_private = sb;
4223         ll_rw_block(READ, 1, &journal->j_sb_buffer);
4224         wait_on_buffer(journal->j_sb_buffer);
4225         if (!buffer_uptodate(journal->j_sb_buffer)) {
4226                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4227                 goto out_journal;
4228         }
4229         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4230                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4231                                         "user (unsupported) - %d",
4232                         be32_to_cpu(journal->j_superblock->s_nr_users));
4233                 goto out_journal;
4234         }
4235         EXT4_SB(sb)->journal_bdev = bdev;
4236         ext4_init_journal_params(sb, journal);
4237         return journal;
4238
4239 out_journal:
4240         jbd2_journal_destroy(journal);
4241 out_bdev:
4242         ext4_blkdev_put(bdev);
4243         return NULL;
4244 }
4245
4246 static int ext4_load_journal(struct super_block *sb,
4247                              struct ext4_super_block *es,
4248                              unsigned long journal_devnum)
4249 {
4250         journal_t *journal;
4251         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4252         dev_t journal_dev;
4253         int err = 0;
4254         int really_read_only;
4255
4256         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4257
4258         if (journal_devnum &&
4259             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4260                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4261                         "numbers have changed");
4262                 journal_dev = new_decode_dev(journal_devnum);
4263         } else
4264                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4265
4266         really_read_only = bdev_read_only(sb->s_bdev);
4267
4268         /*
4269          * Are we loading a blank journal or performing recovery after a
4270          * crash?  For recovery, we need to check in advance whether we
4271          * can get read-write access to the device.
4272          */
4273         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4274                 if (sb->s_flags & MS_RDONLY) {
4275                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4276                                         "required on readonly filesystem");
4277                         if (really_read_only) {
4278                                 ext4_msg(sb, KERN_ERR, "write access "
4279                                         "unavailable, cannot proceed");
4280                                 return -EROFS;
4281                         }
4282                         ext4_msg(sb, KERN_INFO, "write access will "
4283                                "be enabled during recovery");
4284                 }
4285         }
4286
4287         if (journal_inum && journal_dev) {
4288                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4289                        "and inode journals!");
4290                 return -EINVAL;
4291         }
4292
4293         if (journal_inum) {
4294                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4295                         return -EINVAL;
4296         } else {
4297                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4298                         return -EINVAL;
4299         }
4300
4301         if (!(journal->j_flags & JBD2_BARRIER))
4302                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4303
4304         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4305                 err = jbd2_journal_wipe(journal, !really_read_only);
4306         if (!err) {
4307                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4308                 if (save)
4309                         memcpy(save, ((char *) es) +
4310                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4311                 err = jbd2_journal_load(journal);
4312                 if (save)
4313                         memcpy(((char *) es) + EXT4_S_ERR_START,
4314                                save, EXT4_S_ERR_LEN);
4315                 kfree(save);
4316         }
4317
4318         if (err) {
4319                 ext4_msg(sb, KERN_ERR, "error loading journal");
4320                 jbd2_journal_destroy(journal);
4321                 return err;
4322         }
4323
4324         EXT4_SB(sb)->s_journal = journal;
4325         ext4_clear_journal_err(sb, es);
4326
4327         if (!really_read_only && journal_devnum &&
4328             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4329                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4330
4331                 /* Make sure we flush the recovery flag to disk. */
4332                 ext4_commit_super(sb, 1);
4333         }
4334
4335         return 0;
4336 }
4337
4338 static int ext4_commit_super(struct super_block *sb, int sync)
4339 {
4340         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4341         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4342         int error = 0;
4343
4344         if (!sbh || block_device_ejected(sb))
4345                 return error;
4346         if (buffer_write_io_error(sbh)) {
4347                 /*
4348                  * Oh, dear.  A previous attempt to write the
4349                  * superblock failed.  This could happen because the
4350                  * USB device was yanked out.  Or it could happen to
4351                  * be a transient write error and maybe the block will
4352                  * be remapped.  Nothing we can do but to retry the
4353                  * write and hope for the best.
4354                  */
4355                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4356                        "superblock detected");
4357                 clear_buffer_write_io_error(sbh);
4358                 set_buffer_uptodate(sbh);
4359         }
4360         /*
4361          * If the file system is mounted read-only, don't update the
4362          * superblock write time.  This avoids updating the superblock
4363          * write time when we are mounting the root file system
4364          * read/only but we need to replay the journal; at that point,
4365          * for people who are east of GMT and who make their clock
4366          * tick in localtime for Windows bug-for-bug compatibility,
4367          * the clock is set in the future, and this will cause e2fsck
4368          * to complain and force a full file system check.
4369          */
4370         if (!(sb->s_flags & MS_RDONLY))
4371                 es->s_wtime = cpu_to_le32(get_seconds());
4372         if (sb->s_bdev->bd_part)
4373                 es->s_kbytes_written =
4374                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4375                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4376                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4377         else
4378                 es->s_kbytes_written =
4379                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4380         ext4_free_blocks_count_set(es,
4381                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4382                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4383         es->s_free_inodes_count =
4384                 cpu_to_le32(percpu_counter_sum_positive(
4385                                 &EXT4_SB(sb)->s_freeinodes_counter));
4386         BUFFER_TRACE(sbh, "marking dirty");
4387         ext4_superblock_csum_set(sb, es);
4388         mark_buffer_dirty(sbh);
4389         if (sync) {
4390                 error = sync_dirty_buffer(sbh);
4391                 if (error)
4392                         return error;
4393
4394                 error = buffer_write_io_error(sbh);
4395                 if (error) {
4396                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4397                                "superblock");
4398                         clear_buffer_write_io_error(sbh);
4399                         set_buffer_uptodate(sbh);
4400                 }
4401         }
4402         return error;
4403 }
4404
4405 /*
4406  * Have we just finished recovery?  If so, and if we are mounting (or
4407  * remounting) the filesystem readonly, then we will end up with a
4408  * consistent fs on disk.  Record that fact.
4409  */
4410 static void ext4_mark_recovery_complete(struct super_block *sb,
4411                                         struct ext4_super_block *es)
4412 {
4413         journal_t *journal = EXT4_SB(sb)->s_journal;
4414
4415         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4416                 BUG_ON(journal != NULL);
4417                 return;
4418         }
4419         jbd2_journal_lock_updates(journal);
4420         if (jbd2_journal_flush(journal) < 0)
4421                 goto out;
4422
4423         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4424             sb->s_flags & MS_RDONLY) {
4425                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4426                 ext4_commit_super(sb, 1);
4427         }
4428
4429 out:
4430         jbd2_journal_unlock_updates(journal);
4431 }
4432
4433 /*
4434  * If we are mounting (or read-write remounting) a filesystem whose journal
4435  * has recorded an error from a previous lifetime, move that error to the
4436  * main filesystem now.
4437  */
4438 static void ext4_clear_journal_err(struct super_block *sb,
4439                                    struct ext4_super_block *es)
4440 {
4441         journal_t *journal;
4442         int j_errno;
4443         const char *errstr;
4444
4445         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4446
4447         journal = EXT4_SB(sb)->s_journal;
4448
4449         /*
4450          * Now check for any error status which may have been recorded in the
4451          * journal by a prior ext4_error() or ext4_abort()
4452          */
4453
4454         j_errno = jbd2_journal_errno(journal);
4455         if (j_errno) {
4456                 char nbuf[16];
4457
4458                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4459                 ext4_warning(sb, "Filesystem error recorded "
4460                              "from previous mount: %s", errstr);
4461                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4462
4463                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4464                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4465                 ext4_commit_super(sb, 1);
4466
4467                 jbd2_journal_clear_err(journal);
4468                 jbd2_journal_update_sb_errno(journal);
4469         }
4470 }
4471
4472 /*
4473  * Force the running and committing transactions to commit,
4474  * and wait on the commit.
4475  */
4476 int ext4_force_commit(struct super_block *sb)
4477 {
4478         journal_t *journal;
4479         int ret = 0;
4480
4481         if (sb->s_flags & MS_RDONLY)
4482                 return 0;
4483
4484         journal = EXT4_SB(sb)->s_journal;
4485         if (journal)
4486                 ret = ext4_journal_force_commit(journal);
4487
4488         return ret;
4489 }
4490
4491 static int ext4_sync_fs(struct super_block *sb, int wait)
4492 {
4493         int ret = 0;
4494         tid_t target;
4495         struct ext4_sb_info *sbi = EXT4_SB(sb);
4496
4497         trace_ext4_sync_fs(sb, wait);
4498         flush_workqueue(sbi->dio_unwritten_wq);
4499         /*
4500          * Writeback quota in non-journalled quota case - journalled quota has
4501          * no dirty dquots
4502          */
4503         dquot_writeback_dquots(sb, -1);
4504         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4505                 if (wait)
4506                         jbd2_log_wait_commit(sbi->s_journal, target);
4507         }
4508         return ret;
4509 }
4510
4511 /*
4512  * LVM calls this function before a (read-only) snapshot is created.  This
4513  * gives us a chance to flush the journal completely and mark the fs clean.
4514  *
4515  * Note that only this function cannot bring a filesystem to be in a clean
4516  * state independently. It relies on upper layer to stop all data & metadata
4517  * modifications.
4518  */
4519 static int ext4_freeze(struct super_block *sb)
4520 {
4521         int error = 0;
4522         journal_t *journal;
4523
4524         if (sb->s_flags & MS_RDONLY)
4525                 return 0;
4526
4527         journal = EXT4_SB(sb)->s_journal;
4528
4529         /* Now we set up the journal barrier. */
4530         jbd2_journal_lock_updates(journal);
4531
4532         /*
4533          * Don't clear the needs_recovery flag if we failed to flush
4534          * the journal.
4535          */
4536         error = jbd2_journal_flush(journal);
4537         if (error < 0)
4538                 goto out;
4539
4540         /* Journal blocked and flushed, clear needs_recovery flag. */
4541         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4542         error = ext4_commit_super(sb, 1);
4543 out:
4544         /* we rely on upper layer to stop further updates */
4545         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4546         return error;
4547 }
4548
4549 /*
4550  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4551  * flag here, even though the filesystem is not technically dirty yet.
4552  */
4553 static int ext4_unfreeze(struct super_block *sb)
4554 {
4555         if (sb->s_flags & MS_RDONLY)
4556                 return 0;
4557
4558         /* Reset the needs_recovery flag before the fs is unlocked. */
4559         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4560         ext4_commit_super(sb, 1);
4561         return 0;
4562 }
4563
4564 /*
4565  * Structure to save mount options for ext4_remount's benefit
4566  */
4567 struct ext4_mount_options {
4568         unsigned long s_mount_opt;
4569         unsigned long s_mount_opt2;
4570         kuid_t s_resuid;
4571         kgid_t s_resgid;
4572         unsigned long s_commit_interval;
4573         u32 s_min_batch_time, s_max_batch_time;
4574 #ifdef CONFIG_QUOTA
4575         int s_jquota_fmt;
4576         char *s_qf_names[MAXQUOTAS];
4577 #endif
4578 };
4579
4580 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4581 {
4582         struct ext4_super_block *es;
4583         struct ext4_sb_info *sbi = EXT4_SB(sb);
4584         unsigned long old_sb_flags;
4585         struct ext4_mount_options old_opts;
4586         int enable_quota = 0;
4587         ext4_group_t g;
4588         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4589         int err = 0;
4590 #ifdef CONFIG_QUOTA
4591         int i;
4592 #endif
4593         char *orig_data = kstrdup(data, GFP_KERNEL);
4594
4595         /* Store the original options */
4596         old_sb_flags = sb->s_flags;
4597         old_opts.s_mount_opt = sbi->s_mount_opt;
4598         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4599         old_opts.s_resuid = sbi->s_resuid;
4600         old_opts.s_resgid = sbi->s_resgid;
4601         old_opts.s_commit_interval = sbi->s_commit_interval;
4602         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4603         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4604 #ifdef CONFIG_QUOTA
4605         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4606         for (i = 0; i < MAXQUOTAS; i++)
4607                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4608 #endif
4609         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4610                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4611
4612         /*
4613          * Allow the "check" option to be passed as a remount option.
4614          */
4615         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4616                 err = -EINVAL;
4617                 goto restore_opts;
4618         }
4619
4620         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4621                 ext4_abort(sb, "Abort forced by user");
4622
4623         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4624                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4625
4626         es = sbi->s_es;
4627
4628         if (sbi->s_journal) {
4629                 ext4_init_journal_params(sb, sbi->s_journal);
4630                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4631         }
4632
4633         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4634                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4635                         err = -EROFS;
4636                         goto restore_opts;
4637                 }
4638
4639                 if (*flags & MS_RDONLY) {
4640                         err = dquot_suspend(sb, -1);
4641                         if (err < 0)
4642                                 goto restore_opts;
4643
4644                         /*
4645                          * First of all, the unconditional stuff we have to do
4646                          * to disable replay of the journal when we next remount
4647                          */
4648                         sb->s_flags |= MS_RDONLY;
4649
4650                         /*
4651                          * OK, test if we are remounting a valid rw partition
4652                          * readonly, and if so set the rdonly flag and then
4653                          * mark the partition as valid again.
4654                          */
4655                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4656                             (sbi->s_mount_state & EXT4_VALID_FS))
4657                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4658
4659                         if (sbi->s_journal)
4660                                 ext4_mark_recovery_complete(sb, es);
4661                 } else {
4662                         /* Make sure we can mount this feature set readwrite */
4663                         if (!ext4_feature_set_ok(sb, 0)) {
4664                                 err = -EROFS;
4665                                 goto restore_opts;
4666                         }
4667                         /*
4668                          * Make sure the group descriptor checksums
4669                          * are sane.  If they aren't, refuse to remount r/w.
4670                          */
4671                         for (g = 0; g < sbi->s_groups_count; g++) {
4672                                 struct ext4_group_desc *gdp =
4673                                         ext4_get_group_desc(sb, g, NULL);
4674
4675                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4676                                         ext4_msg(sb, KERN_ERR,
4677                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4678                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4679                                                le16_to_cpu(gdp->bg_checksum));
4680                                         err = -EINVAL;
4681                                         goto restore_opts;
4682                                 }
4683                         }
4684
4685                         /*
4686                          * If we have an unprocessed orphan list hanging
4687                          * around from a previously readonly bdev mount,
4688                          * require a full umount/remount for now.
4689                          */
4690                         if (es->s_last_orphan) {
4691                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4692                                        "remount RDWR because of unprocessed "
4693                                        "orphan inode list.  Please "
4694                                        "umount/remount instead");
4695                                 err = -EINVAL;
4696                                 goto restore_opts;
4697                         }
4698
4699                         /*
4700                          * Mounting a RDONLY partition read-write, so reread
4701                          * and store the current valid flag.  (It may have
4702                          * been changed by e2fsck since we originally mounted
4703                          * the partition.)
4704                          */
4705                         if (sbi->s_journal)
4706                                 ext4_clear_journal_err(sb, es);
4707                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4708                         if (!ext4_setup_super(sb, es, 0))
4709                                 sb->s_flags &= ~MS_RDONLY;
4710                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4711                                                      EXT4_FEATURE_INCOMPAT_MMP))
4712                                 if (ext4_multi_mount_protect(sb,
4713                                                 le64_to_cpu(es->s_mmp_block))) {
4714                                         err = -EROFS;
4715                                         goto restore_opts;
4716                                 }
4717                         enable_quota = 1;
4718                 }
4719         }
4720
4721         /*
4722          * Reinitialize lazy itable initialization thread based on
4723          * current settings
4724          */
4725         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4726                 ext4_unregister_li_request(sb);
4727         else {
4728                 ext4_group_t first_not_zeroed;
4729                 first_not_zeroed = ext4_has_uninit_itable(sb);
4730                 ext4_register_li_request(sb, first_not_zeroed);
4731         }
4732
4733         ext4_setup_system_zone(sb);
4734         if (sbi->s_journal == NULL)
4735                 ext4_commit_super(sb, 1);
4736
4737 #ifdef CONFIG_QUOTA
4738         /* Release old quota file names */
4739         for (i = 0; i < MAXQUOTAS; i++)
4740                 if (old_opts.s_qf_names[i] &&
4741                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4742                         kfree(old_opts.s_qf_names[i]);
4743         if (enable_quota) {
4744                 if (sb_any_quota_suspended(sb))
4745                         dquot_resume(sb, -1);
4746                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4747                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4748                         err = ext4_enable_quotas(sb);
4749                         if (err)
4750                                 goto restore_opts;
4751                 }
4752         }
4753 #endif
4754
4755         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4756         kfree(orig_data);
4757         return 0;
4758
4759 restore_opts:
4760         sb->s_flags = old_sb_flags;
4761         sbi->s_mount_opt = old_opts.s_mount_opt;
4762         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4763         sbi->s_resuid = old_opts.s_resuid;
4764         sbi->s_resgid = old_opts.s_resgid;
4765         sbi->s_commit_interval = old_opts.s_commit_interval;
4766         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4767         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4768 #ifdef CONFIG_QUOTA
4769         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4770         for (i = 0; i < MAXQUOTAS; i++) {
4771                 if (sbi->s_qf_names[i] &&
4772                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4773                         kfree(sbi->s_qf_names[i]);
4774                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4775         }
4776 #endif
4777         kfree(orig_data);
4778         return err;
4779 }
4780
4781 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4782 {
4783         struct super_block *sb = dentry->d_sb;
4784         struct ext4_sb_info *sbi = EXT4_SB(sb);
4785         struct ext4_super_block *es = sbi->s_es;
4786         ext4_fsblk_t overhead = 0;
4787         u64 fsid;
4788         s64 bfree;
4789
4790         if (!test_opt(sb, MINIX_DF))
4791                 overhead = sbi->s_overhead;
4792
4793         buf->f_type = EXT4_SUPER_MAGIC;
4794         buf->f_bsize = sb->s_blocksize;
4795         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
4796         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4797                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4798         /* prevent underflow in case that few free space is available */
4799         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4800         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4801         if (buf->f_bfree < ext4_r_blocks_count(es))
4802                 buf->f_bavail = 0;
4803         buf->f_files = le32_to_cpu(es->s_inodes_count);
4804         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4805         buf->f_namelen = EXT4_NAME_LEN;
4806         fsid = le64_to_cpup((void *)es->s_uuid) ^
4807                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4808         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4809         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4810
4811         return 0;
4812 }
4813
4814 /* Helper function for writing quotas on sync - we need to start transaction
4815  * before quota file is locked for write. Otherwise the are possible deadlocks:
4816  * Process 1                         Process 2
4817  * ext4_create()                     quota_sync()
4818  *   jbd2_journal_start()                  write_dquot()
4819  *   dquot_initialize()                         down(dqio_mutex)
4820  *     down(dqio_mutex)                    jbd2_journal_start()
4821  *
4822  */
4823
4824 #ifdef CONFIG_QUOTA
4825
4826 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4827 {
4828         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4829 }
4830
4831 static int ext4_write_dquot(struct dquot *dquot)
4832 {
4833         int ret, err;
4834         handle_t *handle;
4835         struct inode *inode;
4836
4837         inode = dquot_to_inode(dquot);
4838         handle = ext4_journal_start(inode,
4839                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4840         if (IS_ERR(handle))
4841                 return PTR_ERR(handle);
4842         ret = dquot_commit(dquot);
4843         err = ext4_journal_stop(handle);
4844         if (!ret)
4845                 ret = err;
4846         return ret;
4847 }
4848
4849 static int ext4_acquire_dquot(struct dquot *dquot)
4850 {
4851         int ret, err;
4852         handle_t *handle;
4853
4854         handle = ext4_journal_start(dquot_to_inode(dquot),
4855                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4856         if (IS_ERR(handle))
4857                 return PTR_ERR(handle);
4858         ret = dquot_acquire(dquot);
4859         err = ext4_journal_stop(handle);
4860         if (!ret)
4861                 ret = err;
4862         return ret;
4863 }
4864
4865 static int ext4_release_dquot(struct dquot *dquot)
4866 {
4867         int ret, err;
4868         handle_t *handle;
4869
4870         handle = ext4_journal_start(dquot_to_inode(dquot),
4871                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4872         if (IS_ERR(handle)) {
4873                 /* Release dquot anyway to avoid endless cycle in dqput() */
4874                 dquot_release(dquot);
4875                 return PTR_ERR(handle);
4876         }
4877         ret = dquot_release(dquot);
4878         err = ext4_journal_stop(handle);
4879         if (!ret)
4880                 ret = err;
4881         return ret;
4882 }
4883
4884 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4885 {
4886         /* Are we journaling quotas? */
4887         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4888             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4889                 dquot_mark_dquot_dirty(dquot);
4890                 return ext4_write_dquot(dquot);
4891         } else {
4892                 return dquot_mark_dquot_dirty(dquot);
4893         }
4894 }
4895
4896 static int ext4_write_info(struct super_block *sb, int type)
4897 {
4898         int ret, err;
4899         handle_t *handle;
4900
4901         /* Data block + inode block */
4902         handle = ext4_journal_start(sb->s_root->d_inode, 2);
4903         if (IS_ERR(handle))
4904                 return PTR_ERR(handle);
4905         ret = dquot_commit_info(sb, type);
4906         err = ext4_journal_stop(handle);
4907         if (!ret)
4908                 ret = err;
4909         return ret;
4910 }
4911
4912 /*
4913  * Turn on quotas during mount time - we need to find
4914  * the quota file and such...
4915  */
4916 static int ext4_quota_on_mount(struct super_block *sb, int type)
4917 {
4918         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4919                                         EXT4_SB(sb)->s_jquota_fmt, type);
4920 }
4921
4922 /*
4923  * Standard function to be called on quota_on
4924  */
4925 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4926                          struct path *path)
4927 {
4928         int err;
4929
4930         if (!test_opt(sb, QUOTA))
4931                 return -EINVAL;
4932
4933         /* Quotafile not on the same filesystem? */
4934         if (path->dentry->d_sb != sb)
4935                 return -EXDEV;
4936         /* Journaling quota? */
4937         if (EXT4_SB(sb)->s_qf_names[type]) {
4938                 /* Quotafile not in fs root? */
4939                 if (path->dentry->d_parent != sb->s_root)
4940                         ext4_msg(sb, KERN_WARNING,
4941                                 "Quota file not on filesystem root. "
4942                                 "Journaled quota will not work");
4943         }
4944
4945         /*
4946          * When we journal data on quota file, we have to flush journal to see
4947          * all updates to the file when we bypass pagecache...
4948          */
4949         if (EXT4_SB(sb)->s_journal &&
4950             ext4_should_journal_data(path->dentry->d_inode)) {
4951                 /*
4952                  * We don't need to lock updates but journal_flush() could
4953                  * otherwise be livelocked...
4954                  */
4955                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4956                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4957                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4958                 if (err)
4959                         return err;
4960         }
4961
4962         return dquot_quota_on(sb, type, format_id, path);
4963 }
4964
4965 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4966                              unsigned int flags)
4967 {
4968         int err;
4969         struct inode *qf_inode;
4970         unsigned long qf_inums[MAXQUOTAS] = {
4971                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4972                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4973         };
4974
4975         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4976
4977         if (!qf_inums[type])
4978                 return -EPERM;
4979
4980         qf_inode = ext4_iget(sb, qf_inums[type]);
4981         if (IS_ERR(qf_inode)) {
4982                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4983                 return PTR_ERR(qf_inode);
4984         }
4985
4986         err = dquot_enable(qf_inode, type, format_id, flags);
4987         iput(qf_inode);
4988
4989         return err;
4990 }
4991
4992 /* Enable usage tracking for all quota types. */
4993 static int ext4_enable_quotas(struct super_block *sb)
4994 {
4995         int type, err = 0;
4996         unsigned long qf_inums[MAXQUOTAS] = {
4997                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4998                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4999         };
5000
5001         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5002         for (type = 0; type < MAXQUOTAS; type++) {
5003                 if (qf_inums[type]) {
5004                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5005                                                 DQUOT_USAGE_ENABLED);
5006                         if (err) {
5007                                 ext4_warning(sb,
5008                                         "Failed to enable quota (type=%d) "
5009                                         "tracking. Please run e2fsck to fix.",
5010                                         type);
5011                                 return err;
5012                         }
5013                 }
5014         }
5015         return 0;
5016 }
5017
5018 /*
5019  * quota_on function that is used when QUOTA feature is set.
5020  */
5021 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5022                                  int format_id)
5023 {
5024         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5025                 return -EINVAL;
5026
5027         /*
5028          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5029          */
5030         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5031 }
5032
5033 static int ext4_quota_off(struct super_block *sb, int type)
5034 {
5035         struct inode *inode = sb_dqopt(sb)->files[type];
5036         handle_t *handle;
5037
5038         /* Force all delayed allocation blocks to be allocated.
5039          * Caller already holds s_umount sem */
5040         if (test_opt(sb, DELALLOC))
5041                 sync_filesystem(sb);
5042
5043         if (!inode)
5044                 goto out;
5045
5046         /* Update modification times of quota files when userspace can
5047          * start looking at them */
5048         handle = ext4_journal_start(inode, 1);
5049         if (IS_ERR(handle))
5050                 goto out;
5051         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5052         ext4_mark_inode_dirty(handle, inode);
5053         ext4_journal_stop(handle);
5054
5055 out:
5056         return dquot_quota_off(sb, type);
5057 }
5058
5059 /*
5060  * quota_off function that is used when QUOTA feature is set.
5061  */
5062 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5063 {
5064         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5065                 return -EINVAL;
5066
5067         /* Disable only the limits. */
5068         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5069 }
5070
5071 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5072  * acquiring the locks... As quota files are never truncated and quota code
5073  * itself serializes the operations (and no one else should touch the files)
5074  * we don't have to be afraid of races */
5075 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5076                                size_t len, loff_t off)
5077 {
5078         struct inode *inode = sb_dqopt(sb)->files[type];
5079         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5080         int err = 0;
5081         int offset = off & (sb->s_blocksize - 1);
5082         int tocopy;
5083         size_t toread;
5084         struct buffer_head *bh;
5085         loff_t i_size = i_size_read(inode);
5086
5087         if (off > i_size)
5088                 return 0;
5089         if (off+len > i_size)
5090                 len = i_size-off;
5091         toread = len;
5092         while (toread > 0) {
5093                 tocopy = sb->s_blocksize - offset < toread ?
5094                                 sb->s_blocksize - offset : toread;
5095                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5096                 if (err)
5097                         return err;
5098                 if (!bh)        /* A hole? */
5099                         memset(data, 0, tocopy);
5100                 else
5101                         memcpy(data, bh->b_data+offset, tocopy);
5102                 brelse(bh);
5103                 offset = 0;
5104                 toread -= tocopy;
5105                 data += tocopy;
5106                 blk++;
5107         }
5108         return len;
5109 }
5110
5111 /* Write to quotafile (we know the transaction is already started and has
5112  * enough credits) */
5113 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5114                                 const char *data, size_t len, loff_t off)
5115 {
5116         struct inode *inode = sb_dqopt(sb)->files[type];
5117         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5118         int err = 0;
5119         int offset = off & (sb->s_blocksize - 1);
5120         struct buffer_head *bh;
5121         handle_t *handle = journal_current_handle();
5122
5123         if (EXT4_SB(sb)->s_journal && !handle) {
5124                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5125                         " cancelled because transaction is not started",
5126                         (unsigned long long)off, (unsigned long long)len);
5127                 return -EIO;
5128         }
5129         /*
5130          * Since we account only one data block in transaction credits,
5131          * then it is impossible to cross a block boundary.
5132          */
5133         if (sb->s_blocksize - offset < len) {
5134                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5135                         " cancelled because not block aligned",
5136                         (unsigned long long)off, (unsigned long long)len);
5137                 return -EIO;
5138         }
5139
5140         bh = ext4_bread(handle, inode, blk, 1, &err);
5141         if (!bh)
5142                 goto out;
5143         err = ext4_journal_get_write_access(handle, bh);
5144         if (err) {
5145                 brelse(bh);
5146                 goto out;
5147         }
5148         lock_buffer(bh);
5149         memcpy(bh->b_data+offset, data, len);
5150         flush_dcache_page(bh->b_page);
5151         unlock_buffer(bh);
5152         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5153         brelse(bh);
5154 out:
5155         if (err)
5156                 return err;
5157         if (inode->i_size < off + len) {
5158                 i_size_write(inode, off + len);
5159                 EXT4_I(inode)->i_disksize = inode->i_size;
5160                 ext4_mark_inode_dirty(handle, inode);
5161         }
5162         return len;
5163 }
5164
5165 #endif
5166
5167 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5168                        const char *dev_name, void *data)
5169 {
5170         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5171 }
5172
5173 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5174 static inline void register_as_ext2(void)
5175 {
5176         int err = register_filesystem(&ext2_fs_type);
5177         if (err)
5178                 printk(KERN_WARNING
5179                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5180 }
5181
5182 static inline void unregister_as_ext2(void)
5183 {
5184         unregister_filesystem(&ext2_fs_type);
5185 }
5186
5187 static inline int ext2_feature_set_ok(struct super_block *sb)
5188 {
5189         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5190                 return 0;
5191         if (sb->s_flags & MS_RDONLY)
5192                 return 1;
5193         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5194                 return 0;
5195         return 1;
5196 }
5197 MODULE_ALIAS("ext2");
5198 #else
5199 static inline void register_as_ext2(void) { }
5200 static inline void unregister_as_ext2(void) { }
5201 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5202 #endif
5203
5204 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5205 static inline void register_as_ext3(void)
5206 {
5207         int err = register_filesystem(&ext3_fs_type);
5208         if (err)
5209                 printk(KERN_WARNING
5210                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5211 }
5212
5213 static inline void unregister_as_ext3(void)
5214 {
5215         unregister_filesystem(&ext3_fs_type);
5216 }
5217
5218 static inline int ext3_feature_set_ok(struct super_block *sb)
5219 {
5220         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5221                 return 0;
5222         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5223                 return 0;
5224         if (sb->s_flags & MS_RDONLY)
5225                 return 1;
5226         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5227                 return 0;
5228         return 1;
5229 }
5230 MODULE_ALIAS("ext3");
5231 #else
5232 static inline void register_as_ext3(void) { }
5233 static inline void unregister_as_ext3(void) { }
5234 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5235 #endif
5236
5237 static struct file_system_type ext4_fs_type = {
5238         .owner          = THIS_MODULE,
5239         .name           = "ext4",
5240         .mount          = ext4_mount,
5241         .kill_sb        = kill_block_super,
5242         .fs_flags       = FS_REQUIRES_DEV,
5243 };
5244
5245 static int __init ext4_init_feat_adverts(void)
5246 {
5247         struct ext4_features *ef;
5248         int ret = -ENOMEM;
5249
5250         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5251         if (!ef)
5252                 goto out;
5253
5254         ef->f_kobj.kset = ext4_kset;
5255         init_completion(&ef->f_kobj_unregister);
5256         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5257                                    "features");
5258         if (ret) {
5259                 kfree(ef);
5260                 goto out;
5261         }
5262
5263         ext4_feat = ef;
5264         ret = 0;
5265 out:
5266         return ret;
5267 }
5268
5269 static void ext4_exit_feat_adverts(void)
5270 {
5271         kobject_put(&ext4_feat->f_kobj);
5272         wait_for_completion(&ext4_feat->f_kobj_unregister);
5273         kfree(ext4_feat);
5274 }
5275
5276 /* Shared across all ext4 file systems */
5277 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5278 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5279
5280 static int __init ext4_init_fs(void)
5281 {
5282         int i, err;
5283
5284         ext4_li_info = NULL;
5285         mutex_init(&ext4_li_mtx);
5286
5287         ext4_check_flag_values();
5288
5289         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5290                 mutex_init(&ext4__aio_mutex[i]);
5291                 init_waitqueue_head(&ext4__ioend_wq[i]);
5292         }
5293
5294         err = ext4_init_pageio();
5295         if (err)
5296                 return err;
5297         err = ext4_init_system_zone();
5298         if (err)
5299                 goto out6;
5300         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5301         if (!ext4_kset) {
5302                 err = -ENOMEM;
5303                 goto out5;
5304         }
5305         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5306
5307         err = ext4_init_feat_adverts();
5308         if (err)
5309                 goto out4;
5310
5311         err = ext4_init_mballoc();
5312         if (err)
5313                 goto out3;
5314
5315         err = ext4_init_xattr();
5316         if (err)
5317                 goto out2;
5318         err = init_inodecache();
5319         if (err)
5320                 goto out1;
5321         register_as_ext3();
5322         register_as_ext2();
5323         err = register_filesystem(&ext4_fs_type);
5324         if (err)
5325                 goto out;
5326
5327         return 0;
5328 out:
5329         unregister_as_ext2();
5330         unregister_as_ext3();
5331         destroy_inodecache();
5332 out1:
5333         ext4_exit_xattr();
5334 out2:
5335         ext4_exit_mballoc();
5336 out3:
5337         ext4_exit_feat_adverts();
5338 out4:
5339         if (ext4_proc_root)
5340                 remove_proc_entry("fs/ext4", NULL);
5341         kset_unregister(ext4_kset);
5342 out5:
5343         ext4_exit_system_zone();
5344 out6:
5345         ext4_exit_pageio();
5346         return err;
5347 }
5348
5349 static void __exit ext4_exit_fs(void)
5350 {
5351         ext4_destroy_lazyinit_thread();
5352         unregister_as_ext2();
5353         unregister_as_ext3();
5354         unregister_filesystem(&ext4_fs_type);
5355         destroy_inodecache();
5356         ext4_exit_xattr();
5357         ext4_exit_mballoc();
5358         ext4_exit_feat_adverts();
5359         remove_proc_entry("fs/ext4", NULL);
5360         kset_unregister(ext4_kset);
5361         ext4_exit_system_zone();
5362         ext4_exit_pageio();
5363 }
5364
5365 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5366 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5367 MODULE_LICENSE("GPL");
5368 module_init(ext4_init_fs)
5369 module_exit(ext4_exit_fs)