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 <asm/uaccess.h>
  42
  43 #include "ext4.h"
  44 #include "ext4_jbd2.h"
  45 #include "xattr.h"
  46 #include "acl.h"
  47 #include "mballoc.h"
  48
  49 #define CREATE_TRACE_POINTS
  50 #include <trace/events/ext4.h>
  51
  52 struct proc_dir_entry *ext4_proc_root;
  53 static struct kset *ext4_kset;
  54
  55 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  56                              unsigned long journal_devnum);
  57 static int ext4_commit_super(struct super_block *sb, int sync);
  58 static void ext4_mark_recovery_complete(struct super_block *sb,
  59                                         struct ext4_super_block *es);
  60 static void ext4_clear_journal_err(struct super_block *sb,
  61                                    struct ext4_super_block *es);
  62 static int ext4_sync_fs(struct super_block *sb, int wait);
  63 static const char *ext4_decode_error(struct super_block *sb, int errno,
  64                                      char nbuf[16]);
  65 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  66 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  67 static int ext4_unfreeze(struct super_block *sb);
  68 static void ext4_write_super(struct super_block *sb);
  69 static int ext4_freeze(struct super_block *sb);
  70 static int ext4_get_sb(struct file_system_type *fs_type, int flags,
  71                        const char *dev_name, void *data, struct vfsmount *mnt);
  72
  73 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  74 static struct file_system_type ext3_fs_type = {
  75         .owner          = THIS_MODULE,
  76         .name           = "ext3",
  77         .get_sb         = ext4_get_sb,
  78         .kill_sb        = kill_block_super,
  79         .fs_flags       = FS_REQUIRES_DEV,
  80 };
  81 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
  82 #else
  83 #define IS_EXT3_SB(sb) (0)
  84 #endif
  85
  86 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  87                                struct ext4_group_desc *bg)
  88 {
  89         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  90                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  91                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  92 }
  93
  94 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  95                                struct ext4_group_desc *bg)
  96 {
  97         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  98                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  99                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 100 }
 101
 102 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 103                               struct ext4_group_desc *bg)
 104 {
 105         return le32_to_cpu(bg->bg_inode_table_lo) |
 106                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 107                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 108 }
 109
 110 __u32 ext4_free_blks_count(struct super_block *sb,
 111                               struct ext4_group_desc *bg)
 112 {
 113         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 114                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 115                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 116 }
 117
 118 __u32 ext4_free_inodes_count(struct super_block *sb,
 119                               struct ext4_group_desc *bg)
 120 {
 121         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 122                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 123                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 124 }
 125
 126 __u32 ext4_used_dirs_count(struct super_block *sb,
 127                               struct ext4_group_desc *bg)
 128 {
 129         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 130                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 131                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 132 }
 133
 134 __u32 ext4_itable_unused_count(struct super_block *sb,
 135                               struct ext4_group_desc *bg)
 136 {
 137         return le16_to_cpu(bg->bg_itable_unused_lo) |
 138                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 139                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 140 }
 141
 142 void ext4_block_bitmap_set(struct super_block *sb,
 143                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 144 {
 145         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 146         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 147                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 148 }
 149
 150 void ext4_inode_bitmap_set(struct super_block *sb,
 151                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 152 {
 153         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 154         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 155                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 156 }
 157
 158 void ext4_inode_table_set(struct super_block *sb,
 159                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 160 {
 161         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 162         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 163                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 164 }
 165
 166 void ext4_free_blks_set(struct super_block *sb,
 167                           struct ext4_group_desc *bg, __u32 count)
 168 {
 169         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 170         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 171                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 172 }
 173
 174 void ext4_free_inodes_set(struct super_block *sb,
 175                           struct ext4_group_desc *bg, __u32 count)
 176 {
 177         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 178         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 179                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 180 }
 181
 182 void ext4_used_dirs_set(struct super_block *sb,
 183                           struct ext4_group_desc *bg, __u32 count)
 184 {
 185         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 186         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 187                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 188 }
 189
 190 void ext4_itable_unused_set(struct super_block *sb,
 191                           struct ext4_group_desc *bg, __u32 count)
 192 {
 193         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 194         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 195                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 196 }
 197
 198
 199 /* Just increment the non-pointer handle value */
 200 static handle_t *ext4_get_nojournal(void)
 201 {
 202         handle_t *handle = current->journal_info;
 203         unsigned long ref_cnt = (unsigned long)handle;
 204
 205         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
 206
 207         ref_cnt++;
 208         handle = (handle_t *)ref_cnt;
 209
 210         current->journal_info = handle;
 211         return handle;
 212 }
 213
 214
 215 /* Decrement the non-pointer handle value */
 216 static void ext4_put_nojournal(handle_t *handle)
 217 {
 218         unsigned long ref_cnt = (unsigned long)handle;
 219
 220         BUG_ON(ref_cnt == 0);
 221
 222         ref_cnt--;
 223         handle = (handle_t *)ref_cnt;
 224
 225         current->journal_info = handle;
 226 }
 227
 228 /*
 229  * Wrappers for jbd2_journal_start/end.
 230  *
 231  * The only special thing we need to do here is to make sure that all
 232  * journal_end calls result in the superblock being marked dirty, so
 233  * that sync() will call the filesystem's write_super callback if
 234  * appropriate.
 235  */
 236 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 237 {
 238         journal_t *journal;
 239
 240         if (sb->s_flags & MS_RDONLY)
 241                 return ERR_PTR(-EROFS);
 242
 243         vfs_check_frozen(sb, SB_FREEZE_TRANS);
 244         /* Special case here: if the journal has aborted behind our
 245          * backs (eg. EIO in the commit thread), then we still need to
 246          * take the FS itself readonly cleanly. */
 247         journal = EXT4_SB(sb)->s_journal;
 248         if (journal) {
 249                 if (is_journal_aborted(journal)) {
 250                         ext4_abort(sb, "Detected aborted journal");
 251                         return ERR_PTR(-EROFS);
 252                 }
 253                 return jbd2_journal_start(journal, nblocks);
 254         }
 255         return ext4_get_nojournal();
 256 }
 257
 258 /*
 259  * The only special thing we need to do here is to make sure that all
 260  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 261  * that sync() will call the filesystem's write_super callback if
 262  * appropriate.
 263  */
 264 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 265 {
 266         struct super_block *sb;
 267         int err;
 268         int rc;
 269
 270         if (!ext4_handle_valid(handle)) {
 271                 ext4_put_nojournal(handle);
 272                 return 0;
 273         }
 274         sb = handle->h_transaction->t_journal->j_private;
 275         err = handle->h_err;
 276         rc = jbd2_journal_stop(handle);
 277
 278         if (!err)
 279                 err = rc;
 280         if (err)
 281                 __ext4_std_error(sb, where, line, err);
 282         return err;
 283 }
 284
 285 void ext4_journal_abort_handle(const char *caller, unsigned int line,
 286                                const char *err_fn, struct buffer_head *bh,
 287                                handle_t *handle, int err)
 288 {
 289         char nbuf[16];
 290         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 291
 292         BUG_ON(!ext4_handle_valid(handle));
 293
 294         if (bh)
 295                 BUFFER_TRACE(bh, "abort");
 296
 297         if (!handle->h_err)
 298                 handle->h_err = err;
 299
 300         if (is_handle_aborted(handle))
 301                 return;
 302
 303         printk(KERN_ERR "%s:%d: aborting transaction: %s in %s\n",
 304                caller, line, errstr, err_fn);
 305
 306         jbd2_journal_abort_handle(handle);
 307 }
 308
 309 static void __save_error_info(struct super_block *sb, const char *func,
 310                             unsigned int line)
 311 {
 312         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 313
 314         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 315         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 316         es->s_last_error_time = cpu_to_le32(get_seconds());
 317         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 318         es->s_last_error_line = cpu_to_le32(line);
 319         if (!es->s_first_error_time) {
 320                 es->s_first_error_time = es->s_last_error_time;
 321                 strncpy(es->s_first_error_func, func,
 322                         sizeof(es->s_first_error_func));
 323                 es->s_first_error_line = cpu_to_le32(line);
 324                 es->s_first_error_ino = es->s_last_error_ino;
 325                 es->s_first_error_block = es->s_last_error_block;
 326         }
 327         /*
 328          * Start the daily error reporting function if it hasn't been
 329          * started already
 330          */
 331         if (!es->s_error_count)
 332                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 333         es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
 334 }
 335
 336 static void save_error_info(struct super_block *sb, const char *func,
 337                             unsigned int line)
 338 {
 339         __save_error_info(sb, func, line);
 340         ext4_commit_super(sb, 1);
 341 }
 342
 343
 344 /* Deal with the reporting of failure conditions on a filesystem such as
 345  * inconsistencies detected or read IO failures.
 346  *
 347  * On ext2, we can store the error state of the filesystem in the
 348  * superblock.  That is not possible on ext4, because we may have other
 349  * write ordering constraints on the superblock which prevent us from
 350  * writing it out straight away; and given that the journal is about to
 351  * be aborted, we can't rely on the current, or future, transactions to
 352  * write out the superblock safely.
 353  *
 354  * We'll just use the jbd2_journal_abort() error code to record an error in
 355  * the journal instead.  On recovery, the journal will complain about
 356  * that error until we've noted it down and cleared it.
 357  */
 358
 359 static void ext4_handle_error(struct super_block *sb)
 360 {
 361         if (sb->s_flags & MS_RDONLY)
 362                 return;
 363
 364         if (!test_opt(sb, ERRORS_CONT)) {
 365                 journal_t *journal = EXT4_SB(sb)->s_journal;
 366
 367                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 368                 if (journal)
 369                         jbd2_journal_abort(journal, -EIO);
 370         }
 371         if (test_opt(sb, ERRORS_RO)) {
 372                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 373                 sb->s_flags |= MS_RDONLY;
 374         }
 375         if (test_opt(sb, ERRORS_PANIC))
 376                 panic("EXT4-fs (device %s): panic forced after error\n",
 377                         sb->s_id);
 378 }
 379
 380 void __ext4_error(struct super_block *sb, const char *function,
 381                   unsigned int line, const char *fmt, ...)
 382 {
 383         va_list args;
 384
 385         va_start(args, fmt);
 386         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: ",
 387                sb->s_id, function, line, current->comm);
 388         vprintk(fmt, args);
 389         printk("\n");
 390         va_end(args);
 391
 392         ext4_handle_error(sb);
 393 }
 394
 395 void ext4_error_inode(struct inode *inode, const char *function,
 396                       unsigned int line, ext4_fsblk_t block,
 397                       const char *fmt, ...)
 398 {
 399         va_list args;
 400         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 401
 402         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 403         es->s_last_error_block = cpu_to_le64(block);
 404         save_error_info(inode->i_sb, function, line);
 405         va_start(args, fmt);
 406         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
 407                inode->i_sb->s_id, function, line, inode->i_ino);
 408         if (block)
 409                 printk("block %llu: ", block);
 410         printk("comm %s: ", current->comm);
 411         vprintk(fmt, args);
 412         printk("\n");
 413         va_end(args);
 414
 415         ext4_handle_error(inode->i_sb);
 416 }
 417
 418 void ext4_error_file(struct file *file, const char *function,
 419                      unsigned int line, const char *fmt, ...)
 420 {
 421         va_list args;
 422         struct ext4_super_block *es;
 423         struct inode *inode = file->f_dentry->d_inode;
 424         char pathname[80], *path;
 425
 426         es = EXT4_SB(inode->i_sb)->s_es;
 427         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 428         save_error_info(inode->i_sb, function, line);
 429         va_start(args, fmt);
 430         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 431         if (!path)
 432                 path = "(unknown)";
 433         printk(KERN_CRIT
 434                "EXT4-fs error (device %s): %s:%d: inode #%lu "
 435                "(comm %s path %s): ",
 436                inode->i_sb->s_id, function, line, inode->i_ino,
 437                current->comm, path);
 438         vprintk(fmt, args);
 439         printk("\n");
 440         va_end(args);
 441
 442         ext4_handle_error(inode->i_sb);
 443 }
 444
 445 static const char *ext4_decode_error(struct super_block *sb, int errno,
 446                                      char nbuf[16])
 447 {
 448         char *errstr = NULL;
 449
 450         switch (errno) {
 451         case -EIO:
 452                 errstr = "IO failure";
 453                 break;
 454         case -ENOMEM:
 455                 errstr = "Out of memory";
 456                 break;
 457         case -EROFS:
 458                 if (!sb || (EXT4_SB(sb)->s_journal &&
 459                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 460                         errstr = "Journal has aborted";
 461                 else
 462                         errstr = "Readonly filesystem";
 463                 break;
 464         default:
 465                 /* If the caller passed in an extra buffer for unknown
 466                  * errors, textualise them now.  Else we just return
 467                  * NULL. */
 468                 if (nbuf) {
 469                         /* Check for truncated error codes... */
 470                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 471                                 errstr = nbuf;
 472                 }
 473                 break;
 474         }
 475
 476         return errstr;
 477 }
 478
 479 /* __ext4_std_error decodes expected errors from journaling functions
 480  * automatically and invokes the appropriate error response.  */
 481
 482 void __ext4_std_error(struct super_block *sb, const char *function,
 483                       unsigned int line, int errno)
 484 {
 485         char nbuf[16];
 486         const char *errstr;
 487
 488         /* Special case: if the error is EROFS, and we're not already
 489          * inside a transaction, then there's really no point in logging
 490          * an error. */
 491         if (errno == -EROFS && journal_current_handle() == NULL &&
 492             (sb->s_flags & MS_RDONLY))
 493                 return;
 494
 495         errstr = ext4_decode_error(sb, errno, nbuf);
 496         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 497                sb->s_id, function, line, errstr);
 498         save_error_info(sb, function, line);
 499
 500         ext4_handle_error(sb);
 501 }
 502
 503 /*
 504  * ext4_abort is a much stronger failure handler than ext4_error.  The
 505  * abort function may be used to deal with unrecoverable failures such
 506  * as journal IO errors or ENOMEM at a critical moment in log management.
 507  *
 508  * We unconditionally force the filesystem into an ABORT|READONLY state,
 509  * unless the error response on the fs has been set to panic in which
 510  * case we take the easy way out and panic immediately.
 511  */
 512
 513 void __ext4_abort(struct super_block *sb, const char *function,
 514                 unsigned int line, const char *fmt, ...)
 515 {
 516         va_list args;
 517
 518         save_error_info(sb, function, line);
 519         va_start(args, fmt);
 520         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 521                function, line);
 522         vprintk(fmt, args);
 523         printk("\n");
 524         va_end(args);
 525
 526         if ((sb->s_flags & MS_RDONLY) == 0) {
 527                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 528                 sb->s_flags |= MS_RDONLY;
 529                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 530                 if (EXT4_SB(sb)->s_journal)
 531                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 532                 save_error_info(sb, function, line);
 533         }
 534         if (test_opt(sb, ERRORS_PANIC))
 535                 panic("EXT4-fs panic from previous error\n");
 536 }
 537
 538 void ext4_msg (struct super_block * sb, const char *prefix,
 539                    const char *fmt, ...)
 540 {
 541         va_list args;
 542
 543         va_start(args, fmt);
 544         printk("%sEXT4-fs (%s): ", prefix, sb->s_id);
 545         vprintk(fmt, args);
 546         printk("\n");
 547         va_end(args);
 548 }
 549
 550 void __ext4_warning(struct super_block *sb, const char *function,
 551                     unsigned int line, const char *fmt, ...)
 552 {
 553         va_list args;
 554
 555         va_start(args, fmt);
 556         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: ",
 557                sb->s_id, function, line);
 558         vprintk(fmt, args);
 559         printk("\n");
 560         va_end(args);
 561 }
 562
 563 void __ext4_grp_locked_error(const char *function, unsigned int line,
 564                              struct super_block *sb, ext4_group_t grp,
 565                              unsigned long ino, ext4_fsblk_t block,
 566                              const char *fmt, ...)
 567 __releases(bitlock)
 568 __acquires(bitlock)
 569 {
 570         va_list args;
 571         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 572
 573         es->s_last_error_ino = cpu_to_le32(ino);
 574         es->s_last_error_block = cpu_to_le64(block);
 575         __save_error_info(sb, function, line);
 576         va_start(args, fmt);
 577         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u",
 578                sb->s_id, function, line, grp);
 579         if (ino)
 580                 printk("inode %lu: ", ino);
 581         if (block)
 582                 printk("block %llu:", (unsigned long long) block);
 583         vprintk(fmt, args);
 584         printk("\n");
 585         va_end(args);
 586
 587         if (test_opt(sb, ERRORS_CONT)) {
 588                 ext4_commit_super(sb, 0);
 589                 return;
 590         }
 591
 592         ext4_unlock_group(sb, grp);
 593         ext4_handle_error(sb);
 594         /*
 595          * We only get here in the ERRORS_RO case; relocking the group
 596          * may be dangerous, but nothing bad will happen since the
 597          * filesystem will have already been marked read/only and the
 598          * journal has been aborted.  We return 1 as a hint to callers
 599          * who might what to use the return value from
 600          * ext4_grp_locked_error() to distinguish beween the
 601          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 602          * aggressively from the ext4 function in question, with a
 603          * more appropriate error code.
 604          */
 605         ext4_lock_group(sb, grp);
 606         return;
 607 }
 608
 609 void ext4_update_dynamic_rev(struct super_block *sb)
 610 {
 611         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 612
 613         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 614                 return;
 615
 616         ext4_warning(sb,
 617                      "updating to rev %d because of new feature flag, "
 618                      "running e2fsck is recommended",
 619                      EXT4_DYNAMIC_REV);
 620
 621         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 622         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 623         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 624         /* leave es->s_feature_*compat flags alone */
 625         /* es->s_uuid will be set by e2fsck if empty */
 626
 627         /*
 628          * The rest of the superblock fields should be zero, and if not it
 629          * means they are likely already in use, so leave them alone.  We
 630          * can leave it up to e2fsck to clean up any inconsistencies there.
 631          */
 632 }
 633
 634 /*
 635  * Open the external journal device
 636  */
 637 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 638 {
 639         struct block_device *bdev;
 640         char b[BDEVNAME_SIZE];
 641
 642         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 643         if (IS_ERR(bdev))
 644                 goto fail;
 645         return bdev;
 646
 647 fail:
 648         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 649                         __bdevname(dev, b), PTR_ERR(bdev));
 650         return NULL;
 651 }
 652
 653 /*
 654  * Release the journal device
 655  */
 656 static int ext4_blkdev_put(struct block_device *bdev)
 657 {
 658         bd_release(bdev);
 659         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
 660 }
 661
 662 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 663 {
 664         struct block_device *bdev;
 665         int ret = -ENODEV;
 666
 667         bdev = sbi->journal_bdev;
 668         if (bdev) {
 669                 ret = ext4_blkdev_put(bdev);
 670                 sbi->journal_bdev = NULL;
 671         }
 672         return ret;
 673 }
 674
 675 static inline struct inode *orphan_list_entry(struct list_head *l)
 676 {
 677         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 678 }
 679
 680 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 681 {
 682         struct list_head *l;
 683
 684         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 685                  le32_to_cpu(sbi->s_es->s_last_orphan));
 686
 687         printk(KERN_ERR "sb_info orphan list:\n");
 688         list_for_each(l, &sbi->s_orphan) {
 689                 struct inode *inode = orphan_list_entry(l);
 690                 printk(KERN_ERR "  "
 691                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 692                        inode->i_sb->s_id, inode->i_ino, inode,
 693                        inode->i_mode, inode->i_nlink,
 694                        NEXT_ORPHAN(inode));
 695         }
 696 }
 697
 698 static void ext4_put_super(struct super_block *sb)
 699 {
 700         struct ext4_sb_info *sbi = EXT4_SB(sb);
 701         struct ext4_super_block *es = sbi->s_es;
 702         int i, err;
 703
 704         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 705
 706         flush_workqueue(sbi->dio_unwritten_wq);
 707         destroy_workqueue(sbi->dio_unwritten_wq);
 708
 709         lock_super(sb);
 710         if (sb->s_dirt)
 711                 ext4_commit_super(sb, 1);
 712
 713         if (sbi->s_journal) {
 714                 err = jbd2_journal_destroy(sbi->s_journal);
 715                 sbi->s_journal = NULL;
 716                 if (err < 0)
 717                         ext4_abort(sb, "Couldn't clean up the journal");
 718         }
 719
 720         ext4_release_system_zone(sb);
 721         ext4_mb_release(sb);
 722         ext4_ext_release(sb);
 723         ext4_xattr_put_super(sb);
 724
 725         if (!(sb->s_flags & MS_RDONLY)) {
 726                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 727                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 728                 ext4_commit_super(sb, 1);
 729         }
 730         if (sbi->s_proc) {
 731                 remove_proc_entry(sb->s_id, ext4_proc_root);
 732         }
 733         kobject_del(&sbi->s_kobj);
 734
 735         for (i = 0; i < sbi->s_gdb_count; i++)
 736                 brelse(sbi->s_group_desc[i]);
 737         kfree(sbi->s_group_desc);
 738         if (is_vmalloc_addr(sbi->s_flex_groups))
 739                 vfree(sbi->s_flex_groups);
 740         else
 741                 kfree(sbi->s_flex_groups);
 742         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 743         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 744         percpu_counter_destroy(&sbi->s_dirs_counter);
 745         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 746         brelse(sbi->s_sbh);
 747 #ifdef CONFIG_QUOTA
 748         for (i = 0; i < MAXQUOTAS; i++)
 749                 kfree(sbi->s_qf_names[i]);
 750 #endif
 751
 752         /* Debugging code just in case the in-memory inode orphan list
 753          * isn't empty.  The on-disk one can be non-empty if we've
 754          * detected an error and taken the fs readonly, but the
 755          * in-memory list had better be clean by this point. */
 756         if (!list_empty(&sbi->s_orphan))
 757                 dump_orphan_list(sb, sbi);
 758         J_ASSERT(list_empty(&sbi->s_orphan));
 759
 760         invalidate_bdev(sb->s_bdev);
 761         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 762                 /*
 763                  * Invalidate the journal device's buffers.  We don't want them
 764                  * floating about in memory - the physical journal device may
 765                  * hotswapped, and it breaks the `ro-after' testing code.
 766                  */
 767                 sync_blockdev(sbi->journal_bdev);
 768                 invalidate_bdev(sbi->journal_bdev);
 769                 ext4_blkdev_remove(sbi);
 770         }
 771         sb->s_fs_info = NULL;
 772         /*
 773          * Now that we are completely done shutting down the
 774          * superblock, we need to actually destroy the kobject.
 775          */
 776         unlock_super(sb);
 777         kobject_put(&sbi->s_kobj);
 778         wait_for_completion(&sbi->s_kobj_unregister);
 779         kfree(sbi->s_blockgroup_lock);
 780         kfree(sbi);
 781 }
 782
 783 static struct kmem_cache *ext4_inode_cachep;
 784
 785 /*
 786  * Called inside transaction, so use GFP_NOFS
 787  */
 788 static struct inode *ext4_alloc_inode(struct super_block *sb)
 789 {
 790         struct ext4_inode_info *ei;
 791
 792         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 793         if (!ei)
 794                 return NULL;
 795
 796         ei->vfs_inode.i_version = 1;
 797         ei->vfs_inode.i_data.writeback_index = 0;
 798         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 799         INIT_LIST_HEAD(&ei->i_prealloc_list);
 800         spin_lock_init(&ei->i_prealloc_lock);
 801         /*
 802          * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
 803          * therefore it can be null here.  Don't check it, just initialize
 804          * jinode.
 805          */
 806         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
 807         ei->i_reserved_data_blocks = 0;
 808         ei->i_reserved_meta_blocks = 0;
 809         ei->i_allocated_meta_blocks = 0;
 810         ei->i_da_metadata_calc_len = 0;
 811         ei->i_delalloc_reserved_flag = 0;
 812         spin_lock_init(&(ei->i_block_reservation_lock));
 813 #ifdef CONFIG_QUOTA
 814         ei->i_reserved_quota = 0;
 815 #endif
 816         INIT_LIST_HEAD(&ei->i_completed_io_list);
 817         spin_lock_init(&ei->i_completed_io_lock);
 818         ei->cur_aio_dio = NULL;
 819         ei->i_sync_tid = 0;
 820         ei->i_datasync_tid = 0;
 821
 822         return &ei->vfs_inode;
 823 }
 824
 825 static void ext4_destroy_inode(struct inode *inode)
 826 {
 827         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 828                 ext4_msg(inode->i_sb, KERN_ERR,
 829                          "Inode %lu (%p): orphan list check failed!",
 830                          inode->i_ino, EXT4_I(inode));
 831                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 832                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 833                                 true);
 834                 dump_stack();
 835         }
 836         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 837 }
 838
 839 static void init_once(void *foo)
 840 {
 841         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 842
 843         INIT_LIST_HEAD(&ei->i_orphan);
 844 #ifdef CONFIG_EXT4_FS_XATTR
 845         init_rwsem(&ei->xattr_sem);
 846 #endif
 847         init_rwsem(&ei->i_data_sem);
 848         inode_init_once(&ei->vfs_inode);
 849 }
 850
 851 static int init_inodecache(void)
 852 {
 853         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 854                                              sizeof(struct ext4_inode_info),
 855                                              0, (SLAB_RECLAIM_ACCOUNT|
 856                                                 SLAB_MEM_SPREAD),
 857                                              init_once);
 858         if (ext4_inode_cachep == NULL)
 859                 return -ENOMEM;
 860         return 0;
 861 }
 862
 863 static void destroy_inodecache(void)
 864 {
 865         kmem_cache_destroy(ext4_inode_cachep);
 866 }
 867
 868 void ext4_clear_inode(struct inode *inode)
 869 {
 870         invalidate_inode_buffers(inode);
 871         end_writeback(inode);
 872         dquot_drop(inode);
 873         ext4_discard_preallocations(inode);
 874         if (EXT4_JOURNAL(inode))
 875                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 876                                        &EXT4_I(inode)->jinode);
 877 }
 878
 879 static inline void ext4_show_quota_options(struct seq_file *seq,
 880                                            struct super_block *sb)
 881 {
 882 #if defined(CONFIG_QUOTA)
 883         struct ext4_sb_info *sbi = EXT4_SB(sb);
 884
 885         if (sbi->s_jquota_fmt) {
 886                 char *fmtname = "";
 887
 888                 switch (sbi->s_jquota_fmt) {
 889                 case QFMT_VFS_OLD:
 890                         fmtname = "vfsold";
 891                         break;
 892                 case QFMT_VFS_V0:
 893                         fmtname = "vfsv0";
 894                         break;
 895                 case QFMT_VFS_V1:
 896                         fmtname = "vfsv1";
 897                         break;
 898                 }
 899                 seq_printf(seq, ",jqfmt=%s", fmtname);
 900         }
 901
 902         if (sbi->s_qf_names[USRQUOTA])
 903                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 904
 905         if (sbi->s_qf_names[GRPQUOTA])
 906                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 907
 908         if (test_opt(sb, USRQUOTA))
 909                 seq_puts(seq, ",usrquota");
 910
 911         if (test_opt(sb, GRPQUOTA))
 912                 seq_puts(seq, ",grpquota");
 913 #endif
 914 }
 915
 916 /*
 917  * Show an option if
 918  *  - it's set to a non-default value OR
 919  *  - if the per-sb default is different from the global default
 920  */
 921 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 922 {
 923         int def_errors;
 924         unsigned long def_mount_opts;
 925         struct super_block *sb = vfs->mnt_sb;
 926         struct ext4_sb_info *sbi = EXT4_SB(sb);
 927         struct ext4_super_block *es = sbi->s_es;
 928
 929         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 930         def_errors     = le16_to_cpu(es->s_errors);
 931
 932         if (sbi->s_sb_block != 1)
 933                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 934         if (test_opt(sb, MINIX_DF))
 935                 seq_puts(seq, ",minixdf");
 936         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 937                 seq_puts(seq, ",grpid");
 938         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 939                 seq_puts(seq, ",nogrpid");
 940         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 941             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 942                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 943         }
 944         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 945             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 946                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 947         }
 948         if (test_opt(sb, ERRORS_RO)) {
 949                 if (def_errors == EXT4_ERRORS_PANIC ||
 950                     def_errors == EXT4_ERRORS_CONTINUE) {
 951                         seq_puts(seq, ",errors=remount-ro");
 952                 }
 953         }
 954         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 955                 seq_puts(seq, ",errors=continue");
 956         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 957                 seq_puts(seq, ",errors=panic");
 958         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 959                 seq_puts(seq, ",nouid32");
 960         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 961                 seq_puts(seq, ",debug");
 962         if (test_opt(sb, OLDALLOC))
 963                 seq_puts(seq, ",oldalloc");
 964 #ifdef CONFIG_EXT4_FS_XATTR
 965         if (test_opt(sb, XATTR_USER) &&
 966                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 967                 seq_puts(seq, ",user_xattr");
 968         if (!test_opt(sb, XATTR_USER) &&
 969             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 970                 seq_puts(seq, ",nouser_xattr");
 971         }
 972 #endif
 973 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 974         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 975                 seq_puts(seq, ",acl");
 976         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 977                 seq_puts(seq, ",noacl");
 978 #endif
 979         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
 980                 seq_printf(seq, ",commit=%u",
 981                            (unsigned) (sbi->s_commit_interval / HZ));
 982         }
 983         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
 984                 seq_printf(seq, ",min_batch_time=%u",
 985                            (unsigned) sbi->s_min_batch_time);
 986         }
 987         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
 988                 seq_printf(seq, ",max_batch_time=%u",
 989                            (unsigned) sbi->s_min_batch_time);
 990         }
 991
 992         /*
 993          * We're changing the default of barrier mount option, so
 994          * let's always display its mount state so it's clear what its
 995          * status is.
 996          */
 997         seq_puts(seq, ",barrier=");
 998         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 999         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
1000                 seq_puts(seq, ",journal_async_commit");
1001         else if (test_opt(sb, JOURNAL_CHECKSUM))
1002                 seq_puts(seq, ",journal_checksum");
1003         if (test_opt(sb, I_VERSION))
1004                 seq_puts(seq, ",i_version");
1005         if (!test_opt(sb, DELALLOC) &&
1006             !(def_mount_opts & EXT4_DEFM_NODELALLOC))
1007                 seq_puts(seq, ",nodelalloc");
1008
1009         if (sbi->s_stripe)
1010                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
1011         /*
1012          * journal mode get enabled in different ways
1013          * So just print the value even if we didn't specify it
1014          */
1015         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1016                 seq_puts(seq, ",data=journal");
1017         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1018                 seq_puts(seq, ",data=ordered");
1019         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1020                 seq_puts(seq, ",data=writeback");
1021
1022         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1023                 seq_printf(seq, ",inode_readahead_blks=%u",
1024                            sbi->s_inode_readahead_blks);
1025
1026         if (test_opt(sb, DATA_ERR_ABORT))
1027                 seq_puts(seq, ",data_err=abort");
1028
1029         if (test_opt(sb, NO_AUTO_DA_ALLOC))
1030                 seq_puts(seq, ",noauto_da_alloc");
1031
1032         if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
1033                 seq_puts(seq, ",discard");
1034
1035         if (test_opt(sb, NOLOAD))
1036                 seq_puts(seq, ",norecovery");
1037
1038         if (test_opt(sb, DIOREAD_NOLOCK))
1039                 seq_puts(seq, ",dioread_nolock");
1040
1041         if (test_opt(sb, BLOCK_VALIDITY) &&
1042             !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
1043                 seq_puts(seq, ",block_validity");
1044
1045         ext4_show_quota_options(seq, sb);
1046
1047         return 0;
1048 }
1049
1050 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1051                                         u64 ino, u32 generation)
1052 {
1053         struct inode *inode;
1054
1055         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1056                 return ERR_PTR(-ESTALE);
1057         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1058                 return ERR_PTR(-ESTALE);
1059
1060         /* iget isn't really right if the inode is currently unallocated!!
1061          *
1062          * ext4_read_inode will return a bad_inode if the inode had been
1063          * deleted, so we should be safe.
1064          *
1065          * Currently we don't know the generation for parent directory, so
1066          * a generation of 0 means "accept any"
1067          */
1068         inode = ext4_iget(sb, ino);
1069         if (IS_ERR(inode))
1070                 return ERR_CAST(inode);
1071         if (generation && inode->i_generation != generation) {
1072                 iput(inode);
1073                 return ERR_PTR(-ESTALE);
1074         }
1075
1076         return inode;
1077 }
1078
1079 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1080                                         int fh_len, int fh_type)
1081 {
1082         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1083                                     ext4_nfs_get_inode);
1084 }
1085
1086 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1087                                         int fh_len, int fh_type)
1088 {
1089         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1090                                     ext4_nfs_get_inode);
1091 }
1092
1093 /*
1094  * Try to release metadata pages (indirect blocks, directories) which are
1095  * mapped via the block device.  Since these pages could have journal heads
1096  * which would prevent try_to_free_buffers() from freeing them, we must use
1097  * jbd2 layer's try_to_free_buffers() function to release them.
1098  */
1099 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1100                                  gfp_t wait)
1101 {
1102         journal_t *journal = EXT4_SB(sb)->s_journal;
1103
1104         WARN_ON(PageChecked(page));
1105         if (!page_has_buffers(page))
1106                 return 0;
1107         if (journal)
1108                 return jbd2_journal_try_to_free_buffers(journal, page,
1109                                                         wait & ~__GFP_WAIT);
1110         return try_to_free_buffers(page);
1111 }
1112
1113 #ifdef CONFIG_QUOTA
1114 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1115 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1116
1117 static int ext4_write_dquot(struct dquot *dquot);
1118 static int ext4_acquire_dquot(struct dquot *dquot);
1119 static int ext4_release_dquot(struct dquot *dquot);
1120 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1121 static int ext4_write_info(struct super_block *sb, int type);
1122 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1123                                 char *path);
1124 static int ext4_quota_off(struct super_block *sb, int type);
1125 static int ext4_quota_on_mount(struct super_block *sb, int type);
1126 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1127                                size_t len, loff_t off);
1128 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1129                                 const char *data, size_t len, loff_t off);
1130
1131 static const struct dquot_operations ext4_quota_operations = {
1132 #ifdef CONFIG_QUOTA
1133         .get_reserved_space = ext4_get_reserved_space,
1134 #endif
1135         .write_dquot    = ext4_write_dquot,
1136         .acquire_dquot  = ext4_acquire_dquot,
1137         .release_dquot  = ext4_release_dquot,
1138         .mark_dirty     = ext4_mark_dquot_dirty,
1139         .write_info     = ext4_write_info,
1140         .alloc_dquot    = dquot_alloc,
1141         .destroy_dquot  = dquot_destroy,
1142 };
1143
1144 static const struct quotactl_ops ext4_qctl_operations = {
1145         .quota_on       = ext4_quota_on,
1146         .quota_off      = ext4_quota_off,
1147         .quota_sync     = dquot_quota_sync,
1148         .get_info       = dquot_get_dqinfo,
1149         .set_info       = dquot_set_dqinfo,
1150         .get_dqblk      = dquot_get_dqblk,
1151         .set_dqblk      = dquot_set_dqblk
1152 };
1153 #endif
1154
1155 static const struct super_operations ext4_sops = {
1156         .alloc_inode    = ext4_alloc_inode,
1157         .destroy_inode  = ext4_destroy_inode,
1158         .write_inode    = ext4_write_inode,
1159         .dirty_inode    = ext4_dirty_inode,
1160         .evict_inode    = ext4_evict_inode,
1161         .put_super      = ext4_put_super,
1162         .sync_fs        = ext4_sync_fs,
1163         .freeze_fs      = ext4_freeze,
1164         .unfreeze_fs    = ext4_unfreeze,
1165         .statfs         = ext4_statfs,
1166         .remount_fs     = ext4_remount,
1167         .show_options   = ext4_show_options,
1168 #ifdef CONFIG_QUOTA
1169         .quota_read     = ext4_quota_read,
1170         .quota_write    = ext4_quota_write,
1171 #endif
1172         .bdev_try_to_free_page = bdev_try_to_free_page,
1173 };
1174
1175 static const struct super_operations ext4_nojournal_sops = {
1176         .alloc_inode    = ext4_alloc_inode,
1177         .destroy_inode  = ext4_destroy_inode,
1178         .write_inode    = ext4_write_inode,
1179         .dirty_inode    = ext4_dirty_inode,
1180         .evict_inode    = ext4_evict_inode,
1181         .write_super    = ext4_write_super,
1182         .put_super      = ext4_put_super,
1183         .statfs         = ext4_statfs,
1184         .remount_fs     = ext4_remount,
1185         .show_options   = ext4_show_options,
1186 #ifdef CONFIG_QUOTA
1187         .quota_read     = ext4_quota_read,
1188         .quota_write    = ext4_quota_write,
1189 #endif
1190         .bdev_try_to_free_page = bdev_try_to_free_page,
1191 };
1192
1193 static const struct export_operations ext4_export_ops = {
1194         .fh_to_dentry = ext4_fh_to_dentry,
1195         .fh_to_parent = ext4_fh_to_parent,
1196         .get_parent = ext4_get_parent,
1197 };
1198
1199 enum {
1200         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1201         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1202         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1203         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1204         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1205         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1206         Opt_journal_update, Opt_journal_dev,
1207         Opt_journal_checksum, Opt_journal_async_commit,
1208         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1209         Opt_data_err_abort, Opt_data_err_ignore,
1210         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1211         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1212         Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1213         Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1214         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1215         Opt_block_validity, Opt_noblock_validity,
1216         Opt_inode_readahead_blks, Opt_journal_ioprio,
1217         Opt_dioread_nolock, Opt_dioread_lock,
1218         Opt_discard, Opt_nodiscard,
1219 };
1220
1221 static const match_table_t tokens = {
1222         {Opt_bsd_df, "bsddf"},
1223         {Opt_minix_df, "minixdf"},
1224         {Opt_grpid, "grpid"},
1225         {Opt_grpid, "bsdgroups"},
1226         {Opt_nogrpid, "nogrpid"},
1227         {Opt_nogrpid, "sysvgroups"},
1228         {Opt_resgid, "resgid=%u"},
1229         {Opt_resuid, "resuid=%u"},
1230         {Opt_sb, "sb=%u"},
1231         {Opt_err_cont, "errors=continue"},
1232         {Opt_err_panic, "errors=panic"},
1233         {Opt_err_ro, "errors=remount-ro"},
1234         {Opt_nouid32, "nouid32"},
1235         {Opt_debug, "debug"},
1236         {Opt_oldalloc, "oldalloc"},
1237         {Opt_orlov, "orlov"},
1238         {Opt_user_xattr, "user_xattr"},
1239         {Opt_nouser_xattr, "nouser_xattr"},
1240         {Opt_acl, "acl"},
1241         {Opt_noacl, "noacl"},
1242         {Opt_noload, "noload"},
1243         {Opt_noload, "norecovery"},
1244         {Opt_nobh, "nobh"},
1245         {Opt_bh, "bh"},
1246         {Opt_commit, "commit=%u"},
1247         {Opt_min_batch_time, "min_batch_time=%u"},
1248         {Opt_max_batch_time, "max_batch_time=%u"},
1249         {Opt_journal_update, "journal=update"},
1250         {Opt_journal_dev, "journal_dev=%u"},
1251         {Opt_journal_checksum, "journal_checksum"},
1252         {Opt_journal_async_commit, "journal_async_commit"},
1253         {Opt_abort, "abort"},
1254         {Opt_data_journal, "data=journal"},
1255         {Opt_data_ordered, "data=ordered"},
1256         {Opt_data_writeback, "data=writeback"},
1257         {Opt_data_err_abort, "data_err=abort"},
1258         {Opt_data_err_ignore, "data_err=ignore"},
1259         {Opt_offusrjquota, "usrjquota="},
1260         {Opt_usrjquota, "usrjquota=%s"},
1261         {Opt_offgrpjquota, "grpjquota="},
1262         {Opt_grpjquota, "grpjquota=%s"},
1263         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1264         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1265         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1266         {Opt_grpquota, "grpquota"},
1267         {Opt_noquota, "noquota"},
1268         {Opt_quota, "quota"},
1269         {Opt_usrquota, "usrquota"},
1270         {Opt_barrier, "barrier=%u"},
1271         {Opt_barrier, "barrier"},
1272         {Opt_nobarrier, "nobarrier"},
1273         {Opt_i_version, "i_version"},
1274         {Opt_stripe, "stripe=%u"},
1275         {Opt_resize, "resize"},
1276         {Opt_delalloc, "delalloc"},
1277         {Opt_nodelalloc, "nodelalloc"},
1278         {Opt_block_validity, "block_validity"},
1279         {Opt_noblock_validity, "noblock_validity"},
1280         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1281         {Opt_journal_ioprio, "journal_ioprio=%u"},
1282         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1283         {Opt_auto_da_alloc, "auto_da_alloc"},
1284         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1285         {Opt_dioread_nolock, "dioread_nolock"},
1286         {Opt_dioread_lock, "dioread_lock"},
1287         {Opt_discard, "discard"},
1288         {Opt_nodiscard, "nodiscard"},
1289         {Opt_err, NULL},
1290 };
1291
1292 static ext4_fsblk_t get_sb_block(void **data)
1293 {
1294         ext4_fsblk_t    sb_block;
1295         char            *options = (char *) *data;
1296
1297         if (!options || strncmp(options, "sb=", 3) != 0)
1298                 return 1;       /* Default location */
1299
1300         options += 3;
1301         /* TODO: use simple_strtoll with >32bit ext4 */
1302         sb_block = simple_strtoul(options, &options, 0);
1303         if (*options && *options != ',') {
1304                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1305                        (char *) *data);
1306                 return 1;
1307         }
1308         if (*options == ',')
1309                 options++;
1310         *data = (void *) options;
1311
1312         return sb_block;
1313 }
1314
1315 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1316 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1317         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1318
1319 #ifdef CONFIG_QUOTA
1320 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1321 {
1322         struct ext4_sb_info *sbi = EXT4_SB(sb);
1323         char *qname;
1324
1325         if (sb_any_quota_loaded(sb) &&
1326                 !sbi->s_qf_names[qtype]) {
1327                 ext4_msg(sb, KERN_ERR,
1328                         "Cannot change journaled "
1329                         "quota options when quota turned on");
1330                 return 0;
1331         }
1332         qname = match_strdup(args);
1333         if (!qname) {
1334                 ext4_msg(sb, KERN_ERR,
1335                         "Not enough memory for storing quotafile name");
1336                 return 0;
1337         }
1338         if (sbi->s_qf_names[qtype] &&
1339                 strcmp(sbi->s_qf_names[qtype], qname)) {
1340                 ext4_msg(sb, KERN_ERR,
1341                         "%s quota file already specified", QTYPE2NAME(qtype));
1342                 kfree(qname);
1343                 return 0;
1344         }
1345         sbi->s_qf_names[qtype] = qname;
1346         if (strchr(sbi->s_qf_names[qtype], '/')) {
1347                 ext4_msg(sb, KERN_ERR,
1348                         "quotafile must be on filesystem root");
1349                 kfree(sbi->s_qf_names[qtype]);
1350                 sbi->s_qf_names[qtype] = NULL;
1351                 return 0;
1352         }
1353         set_opt(sbi->s_mount_opt, QUOTA);
1354         return 1;
1355 }
1356
1357 static int clear_qf_name(struct super_block *sb, int qtype)
1358 {
1359
1360         struct ext4_sb_info *sbi = EXT4_SB(sb);
1361
1362         if (sb_any_quota_loaded(sb) &&
1363                 sbi->s_qf_names[qtype]) {
1364                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1365                         " when quota turned on");
1366                 return 0;
1367         }
1368         /*
1369          * The space will be released later when all options are confirmed
1370          * to be correct
1371          */
1372         sbi->s_qf_names[qtype] = NULL;
1373         return 1;
1374 }
1375 #endif
1376
1377 static int parse_options(char *options, struct super_block *sb,
1378                          unsigned long *journal_devnum,
1379                          unsigned int *journal_ioprio,
1380                          ext4_fsblk_t *n_blocks_count, int is_remount)
1381 {
1382         struct ext4_sb_info *sbi = EXT4_SB(sb);
1383         char *p;
1384         substring_t args[MAX_OPT_ARGS];
1385         int data_opt = 0;
1386         int option;
1387 #ifdef CONFIG_QUOTA
1388         int qfmt;
1389 #endif
1390
1391         if (!options)
1392                 return 1;
1393
1394         while ((p = strsep(&options, ",")) != NULL) {
1395                 int token;
1396                 if (!*p)
1397                         continue;
1398
1399                 /*
1400                  * Initialize args struct so we know whether arg was
1401                  * found; some options take optional arguments.
1402                  */
1403                 args[0].to = args[0].from = 0;
1404                 token = match_token(p, tokens, args);
1405                 switch (token) {
1406                 case Opt_bsd_df:
1407                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1408                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1409                         break;
1410                 case Opt_minix_df:
1411                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1412                         set_opt(sbi->s_mount_opt, MINIX_DF);
1413
1414                         break;
1415                 case Opt_grpid:
1416                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1417                         set_opt(sbi->s_mount_opt, GRPID);
1418
1419                         break;
1420                 case Opt_nogrpid:
1421                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1422                         clear_opt(sbi->s_mount_opt, GRPID);
1423
1424                         break;
1425                 case Opt_resuid:
1426                         if (match_int(&args[0], &option))
1427                                 return 0;
1428                         sbi->s_resuid = option;
1429                         break;
1430                 case Opt_resgid:
1431                         if (match_int(&args[0], &option))
1432                                 return 0;
1433                         sbi->s_resgid = option;
1434                         break;
1435                 case Opt_sb:
1436                         /* handled by get_sb_block() instead of here */
1437                         /* *sb_block = match_int(&args[0]); */
1438                         break;
1439                 case Opt_err_panic:
1440                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1441                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1442                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1443                         break;
1444                 case Opt_err_ro:
1445                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1446                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1447                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1448                         break;
1449                 case Opt_err_cont:
1450                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1451                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1452                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1453                         break;
1454                 case Opt_nouid32:
1455                         set_opt(sbi->s_mount_opt, NO_UID32);
1456                         break;
1457                 case Opt_debug:
1458                         set_opt(sbi->s_mount_opt, DEBUG);
1459                         break;
1460                 case Opt_oldalloc:
1461                         set_opt(sbi->s_mount_opt, OLDALLOC);
1462                         break;
1463                 case Opt_orlov:
1464                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1465                         break;
1466 #ifdef CONFIG_EXT4_FS_XATTR
1467                 case Opt_user_xattr:
1468                         set_opt(sbi->s_mount_opt, XATTR_USER);
1469                         break;
1470                 case Opt_nouser_xattr:
1471                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1472                         break;
1473 #else
1474                 case Opt_user_xattr:
1475                 case Opt_nouser_xattr:
1476                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1477                         break;
1478 #endif
1479 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1480                 case Opt_acl:
1481                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1482                         break;
1483                 case Opt_noacl:
1484                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1485                         break;
1486 #else
1487                 case Opt_acl:
1488                 case Opt_noacl:
1489                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1490                         break;
1491 #endif
1492                 case Opt_journal_update:
1493                         /* @@@ FIXME */
1494                         /* Eventually we will want to be able to create
1495                            a journal file here.  For now, only allow the
1496                            user to specify an existing inode to be the
1497                            journal file. */
1498                         if (is_remount) {
1499                                 ext4_msg(sb, KERN_ERR,
1500                                          "Cannot specify journal on remount");
1501                                 return 0;
1502                         }
1503                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1504                         break;
1505                 case Opt_journal_dev:
1506                         if (is_remount) {
1507                                 ext4_msg(sb, KERN_ERR,
1508                                         "Cannot specify journal on remount");
1509                                 return 0;
1510                         }
1511                         if (match_int(&args[0], &option))
1512                                 return 0;
1513                         *journal_devnum = option;
1514                         break;
1515                 case Opt_journal_checksum:
1516                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1517                         break;
1518                 case Opt_journal_async_commit:
1519                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1520                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1521                         break;
1522                 case Opt_noload:
1523                         set_opt(sbi->s_mount_opt, NOLOAD);
1524                         break;
1525                 case Opt_commit:
1526                         if (match_int(&args[0], &option))
1527                                 return 0;
1528                         if (option < 0)
1529                                 return 0;
1530                         if (option == 0)
1531                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1532                         sbi->s_commit_interval = HZ * option;
1533                         break;
1534                 case Opt_max_batch_time:
1535                         if (match_int(&args[0], &option))
1536                                 return 0;
1537                         if (option < 0)
1538                                 return 0;
1539                         if (option == 0)
1540                                 option = EXT4_DEF_MAX_BATCH_TIME;
1541                         sbi->s_max_batch_time = option;
1542                         break;
1543                 case Opt_min_batch_time:
1544                         if (match_int(&args[0], &option))
1545                                 return 0;
1546                         if (option < 0)
1547                                 return 0;
1548                         sbi->s_min_batch_time = option;
1549                         break;
1550                 case Opt_data_journal:
1551                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1552                         goto datacheck;
1553                 case Opt_data_ordered:
1554                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1555                         goto datacheck;
1556                 case Opt_data_writeback:
1557                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1558                 datacheck:
1559                         if (is_remount) {
1560                                 if (test_opt(sb, DATA_FLAGS) != data_opt) {
1561                                         ext4_msg(sb, KERN_ERR,
1562                                                 "Cannot change data mode on remount");
1563                                         return 0;
1564                                 }
1565                         } else {
1566                                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
1567                                 sbi->s_mount_opt |= data_opt;
1568                         }
1569                         break;
1570                 case Opt_data_err_abort:
1571                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1572                         break;
1573                 case Opt_data_err_ignore:
1574                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1575                         break;
1576 #ifdef CONFIG_QUOTA
1577                 case Opt_usrjquota:
1578                         if (!set_qf_name(sb, USRQUOTA, &args[0]))
1579                                 return 0;
1580                         break;
1581                 case Opt_grpjquota:
1582                         if (!set_qf_name(sb, GRPQUOTA, &args[0]))
1583                                 return 0;
1584                         break;
1585                 case Opt_offusrjquota:
1586                         if (!clear_qf_name(sb, USRQUOTA))
1587                                 return 0;
1588                         break;
1589                 case Opt_offgrpjquota:
1590                         if (!clear_qf_name(sb, GRPQUOTA))
1591                                 return 0;
1592                         break;
1593
1594                 case Opt_jqfmt_vfsold:
1595                         qfmt = QFMT_VFS_OLD;
1596                         goto set_qf_format;
1597                 case Opt_jqfmt_vfsv0:
1598                         qfmt = QFMT_VFS_V0;
1599                         goto set_qf_format;
1600                 case Opt_jqfmt_vfsv1:
1601                         qfmt = QFMT_VFS_V1;
1602 set_qf_format:
1603                         if (sb_any_quota_loaded(sb) &&
1604                             sbi->s_jquota_fmt != qfmt) {
1605                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1606                                         "journaled quota options when "
1607                                         "quota turned on");
1608                                 return 0;
1609                         }
1610                         sbi->s_jquota_fmt = qfmt;
1611                         break;
1612                 case Opt_quota:
1613                 case Opt_usrquota:
1614                         set_opt(sbi->s_mount_opt, QUOTA);
1615                         set_opt(sbi->s_mount_opt, USRQUOTA);
1616                         break;
1617                 case Opt_grpquota:
1618                         set_opt(sbi->s_mount_opt, QUOTA);
1619                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1620                         break;
1621                 case Opt_noquota:
1622                         if (sb_any_quota_loaded(sb)) {
1623                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1624                                         "options when quota turned on");
1625                                 return 0;
1626                         }
1627                         clear_opt(sbi->s_mount_opt, QUOTA);
1628                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1629                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1630                         break;
1631 #else
1632                 case Opt_quota:
1633                 case Opt_usrquota:
1634                 case Opt_grpquota:
1635                         ext4_msg(sb, KERN_ERR,
1636                                 "quota options not supported");
1637                         break;
1638                 case Opt_usrjquota:
1639                 case Opt_grpjquota:
1640                 case Opt_offusrjquota:
1641                 case Opt_offgrpjquota:
1642                 case Opt_jqfmt_vfsold:
1643                 case Opt_jqfmt_vfsv0:
1644                 case Opt_jqfmt_vfsv1:
1645                         ext4_msg(sb, KERN_ERR,
1646                                 "journaled quota options not supported");
1647                         break;
1648                 case Opt_noquota:
1649                         break;
1650 #endif
1651                 case Opt_abort:
1652                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1653                         break;
1654                 case Opt_nobarrier:
1655                         clear_opt(sbi->s_mount_opt, BARRIER);
1656                         break;
1657                 case Opt_barrier:
1658                         if (args[0].from) {
1659                                 if (match_int(&args[0], &option))
1660                                         return 0;
1661                         } else
1662                                 option = 1;     /* No argument, default to 1 */
1663                         if (option)
1664                                 set_opt(sbi->s_mount_opt, BARRIER);
1665                         else
1666                                 clear_opt(sbi->s_mount_opt, BARRIER);
1667                         break;
1668                 case Opt_ignore:
1669                         break;
1670                 case Opt_resize:
1671                         if (!is_remount) {
1672                                 ext4_msg(sb, KERN_ERR,
1673                                         "resize option only available "
1674                                         "for remount");
1675                                 return 0;
1676                         }
1677                         if (match_int(&args[0], &option) != 0)
1678                                 return 0;
1679                         *n_blocks_count = option;
1680                         break;
1681                 case Opt_nobh:
1682                         ext4_msg(sb, KERN_WARNING,
1683                                  "Ignoring deprecated nobh option");
1684                         break;
1685                 case Opt_bh:
1686                         ext4_msg(sb, KERN_WARNING,
1687                                  "Ignoring deprecated bh option");
1688                         break;
1689                 case Opt_i_version:
1690                         set_opt(sbi->s_mount_opt, I_VERSION);
1691                         sb->s_flags |= MS_I_VERSION;
1692                         break;
1693                 case Opt_nodelalloc:
1694                         clear_opt(sbi->s_mount_opt, DELALLOC);
1695                         break;
1696                 case Opt_stripe:
1697                         if (match_int(&args[0], &option))
1698                                 return 0;
1699                         if (option < 0)
1700                                 return 0;
1701                         sbi->s_stripe = option;
1702                         break;
1703                 case Opt_delalloc:
1704                         set_opt(sbi->s_mount_opt, DELALLOC);
1705                         break;
1706                 case Opt_block_validity:
1707                         set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1708                         break;
1709                 case Opt_noblock_validity:
1710                         clear_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1711                         break;
1712                 case Opt_inode_readahead_blks:
1713                         if (match_int(&args[0], &option))
1714                                 return 0;
1715                         if (option < 0 || option > (1 << 30))
1716                                 return 0;
1717                         if (!is_power_of_2(option)) {
1718                                 ext4_msg(sb, KERN_ERR,
1719                                          "EXT4-fs: inode_readahead_blks"
1720                                          " must be a power of 2");
1721                                 return 0;
1722                         }
1723                         sbi->s_inode_readahead_blks = option;
1724                         break;
1725                 case Opt_journal_ioprio:
1726                         if (match_int(&args[0], &option))
1727                                 return 0;
1728                         if (option < 0 || option > 7)
1729                                 break;
1730                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1731                                                             option);
1732                         break;
1733                 case Opt_noauto_da_alloc:
1734                         set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1735                         break;
1736                 case Opt_auto_da_alloc:
1737                         if (args[0].from) {
1738                                 if (match_int(&args[0], &option))
1739                                         return 0;
1740                         } else
1741                                 option = 1;     /* No argument, default to 1 */
1742                         if (option)
1743                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1744                         else
1745                                 set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1746                         break;
1747                 case Opt_discard:
1748                         set_opt(sbi->s_mount_opt, DISCARD);
1749                         break;
1750                 case Opt_nodiscard:
1751                         clear_opt(sbi->s_mount_opt, DISCARD);
1752                         break;
1753                 case Opt_dioread_nolock:
1754                         set_opt(sbi->s_mount_opt, DIOREAD_NOLOCK);
1755                         break;
1756                 case Opt_dioread_lock:
1757                         clear_opt(sbi->s_mount_opt, DIOREAD_NOLOCK);
1758                         break;
1759                 default:
1760                         ext4_msg(sb, KERN_ERR,
1761                                "Unrecognized mount option \"%s\" "
1762                                "or missing value", p);
1763                         return 0;
1764                 }
1765         }
1766 #ifdef CONFIG_QUOTA
1767         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1768                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1769                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1770
1771                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1772                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1773
1774                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1775                         ext4_msg(sb, KERN_ERR, "old and new quota "
1776                                         "format mixing");
1777                         return 0;
1778                 }
1779
1780                 if (!sbi->s_jquota_fmt) {
1781                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1782                                         "not specified");
1783                         return 0;
1784                 }
1785         } else {
1786                 if (sbi->s_jquota_fmt) {
1787                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1788                                         "specified with no journaling "
1789                                         "enabled");
1790                         return 0;
1791                 }
1792         }
1793 #endif
1794         return 1;
1795 }
1796
1797 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1798                             int read_only)
1799 {
1800         struct ext4_sb_info *sbi = EXT4_SB(sb);
1801         int res = 0;
1802
1803         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1804                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1805                          "forcing read-only mode");
1806                 res = MS_RDONLY;
1807         }
1808         if (read_only)
1809                 return res;
1810         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1811                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1812                          "running e2fsck is recommended");
1813         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1814                 ext4_msg(sb, KERN_WARNING,
1815                          "warning: mounting fs with errors, "
1816                          "running e2fsck is recommended");
1817         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1818                  le16_to_cpu(es->s_mnt_count) >=
1819                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1820                 ext4_msg(sb, KERN_WARNING,
1821                          "warning: maximal mount count reached, "
1822                          "running e2fsck is recommended");
1823         else if (le32_to_cpu(es->s_checkinterval) &&
1824                 (le32_to_cpu(es->s_lastcheck) +
1825                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1826                 ext4_msg(sb, KERN_WARNING,
1827                          "warning: checktime reached, "
1828                          "running e2fsck is recommended");
1829         if (!sbi->s_journal)
1830                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1831         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1832                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1833         le16_add_cpu(&es->s_mnt_count, 1);
1834         es->s_mtime = cpu_to_le32(get_seconds());
1835         ext4_update_dynamic_rev(sb);
1836         if (sbi->s_journal)
1837                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1838
1839         ext4_commit_super(sb, 1);
1840         if (test_opt(sb, DEBUG))
1841                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1842                                 "bpg=%lu, ipg=%lu, mo=%04x]\n",
1843                         sb->s_blocksize,
1844                         sbi->s_groups_count,
1845                         EXT4_BLOCKS_PER_GROUP(sb),
1846                         EXT4_INODES_PER_GROUP(sb),
1847                         sbi->s_mount_opt);
1848
1849         return res;
1850 }
1851
1852 static int ext4_fill_flex_info(struct super_block *sb)
1853 {
1854         struct ext4_sb_info *sbi = EXT4_SB(sb);
1855         struct ext4_group_desc *gdp = NULL;
1856         ext4_group_t flex_group_count;
1857         ext4_group_t flex_group;
1858         int groups_per_flex = 0;
1859         size_t size;
1860         int i;
1861
1862         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1863         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1864
1865         if (groups_per_flex < 2) {
1866                 sbi->s_log_groups_per_flex = 0;
1867                 return 1;
1868         }
1869
1870         /* We allocate both existing and potentially added groups */
1871         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1872                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1873                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1874         size = flex_group_count * sizeof(struct flex_groups);
1875         sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1876         if (sbi->s_flex_groups == NULL) {
1877                 sbi->s_flex_groups = vmalloc(size);
1878                 if (sbi->s_flex_groups)
1879                         memset(sbi->s_flex_groups, 0, size);
1880         }
1881         if (sbi->s_flex_groups == NULL) {
1882                 ext4_msg(sb, KERN_ERR, "not enough memory for "
1883                                 "%u flex groups", flex_group_count);
1884                 goto failed;
1885         }
1886
1887         for (i = 0; i < sbi->s_groups_count; i++) {
1888                 gdp = ext4_get_group_desc(sb, i, NULL);
1889
1890                 flex_group = ext4_flex_group(sbi, i);
1891                 atomic_add(ext4_free_inodes_count(sb, gdp),
1892                            &sbi->s_flex_groups[flex_group].free_inodes);
1893                 atomic_add(ext4_free_blks_count(sb, gdp),
1894                            &sbi->s_flex_groups[flex_group].free_blocks);
1895                 atomic_add(ext4_used_dirs_count(sb, gdp),
1896                            &sbi->s_flex_groups[flex_group].used_dirs);
1897         }
1898
1899         return 1;
1900 failed:
1901         return 0;
1902 }
1903
1904 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1905                             struct ext4_group_desc *gdp)
1906 {
1907         __u16 crc = 0;
1908
1909         if (sbi->s_es->s_feature_ro_compat &
1910             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1911                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1912                 __le32 le_group = cpu_to_le32(block_group);
1913
1914                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1915                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1916                 crc = crc16(crc, (__u8 *)gdp, offset);
1917                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1918                 /* for checksum of struct ext4_group_desc do the rest...*/
1919                 if ((sbi->s_es->s_feature_incompat &
1920                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1921                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1922                         crc = crc16(crc, (__u8 *)gdp + offset,
1923                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1924                                         offset);
1925         }
1926
1927         return cpu_to_le16(crc);
1928 }
1929
1930 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1931                                 struct ext4_group_desc *gdp)
1932 {
1933         if ((sbi->s_es->s_feature_ro_compat &
1934              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1935             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1936                 return 0;
1937
1938         return 1;
1939 }
1940
1941 /* Called at mount-time, super-block is locked */
1942 static int ext4_check_descriptors(struct super_block *sb)
1943 {
1944         struct ext4_sb_info *sbi = EXT4_SB(sb);
1945         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1946         ext4_fsblk_t last_block;
1947         ext4_fsblk_t block_bitmap;
1948         ext4_fsblk_t inode_bitmap;
1949         ext4_fsblk_t inode_table;
1950         int flexbg_flag = 0;
1951         ext4_group_t i;
1952
1953         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1954                 flexbg_flag = 1;
1955
1956         ext4_debug("Checking group descriptors");
1957
1958         for (i = 0; i < sbi->s_groups_count; i++) {
1959                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1960
1961                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1962                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1963                 else
1964                         last_block = first_block +
1965                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1966
1967                 block_bitmap = ext4_block_bitmap(sb, gdp);
1968                 if (block_bitmap < first_block || block_bitmap > last_block) {
1969                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1970                                "Block bitmap for group %u not in group "
1971                                "(block %llu)!", i, block_bitmap);
1972                         return 0;
1973                 }
1974                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1975                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1976                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1977                                "Inode bitmap for group %u not in group "
1978                                "(block %llu)!", i, inode_bitmap);
1979                         return 0;
1980                 }
1981                 inode_table = ext4_inode_table(sb, gdp);
1982                 if (inode_table < first_block ||
1983                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1984                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1985                                "Inode table for group %u not in group "
1986                                "(block %llu)!", i, inode_table);
1987                         return 0;
1988                 }
1989                 ext4_lock_group(sb, i);
1990                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1991                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1992                                  "Checksum for group %u failed (%u!=%u)",
1993                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1994                                      gdp)), le16_to_cpu(gdp->bg_checksum));
1995                         if (!(sb->s_flags & MS_RDONLY)) {
1996                                 ext4_unlock_group(sb, i);
1997                                 return 0;
1998                         }
1999                 }
2000                 ext4_unlock_group(sb, i);
2001                 if (!flexbg_flag)
2002                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2003         }
2004
2005         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
2006         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2007         return 1;
2008 }
2009
2010 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2011  * the superblock) which were deleted from all directories, but held open by
2012  * a process at the time of a crash.  We walk the list and try to delete these
2013  * inodes at recovery time (only with a read-write filesystem).
2014  *
2015  * In order to keep the orphan inode chain consistent during traversal (in
2016  * case of crash during recovery), we link each inode into the superblock
2017  * orphan list_head and handle it the same way as an inode deletion during
2018  * normal operation (which journals the operations for us).
2019  *
2020  * We only do an iget() and an iput() on each inode, which is very safe if we
2021  * accidentally point at an in-use or already deleted inode.  The worst that
2022  * can happen in this case is that we get a "bit already cleared" message from
2023  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2024  * e2fsck was run on this filesystem, and it must have already done the orphan
2025  * inode cleanup for us, so we can safely abort without any further action.
2026  */
2027 static void ext4_orphan_cleanup(struct super_block *sb,
2028                                 struct ext4_super_block *es)
2029 {
2030         unsigned int s_flags = sb->s_flags;
2031         int nr_orphans = 0, nr_truncates = 0;
2032 #ifdef CONFIG_QUOTA
2033         int i;
2034 #endif
2035         if (!es->s_last_orphan) {
2036                 jbd_debug(4, "no orphan inodes to clean up\n");
2037                 return;
2038         }
2039
2040         if (bdev_read_only(sb->s_bdev)) {
2041                 ext4_msg(sb, KERN_ERR, "write access "
2042                         "unavailable, skipping orphan cleanup");
2043                 return;
2044         }
2045
2046         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2047                 if (es->s_last_orphan)
2048                         jbd_debug(1, "Errors on filesystem, "
2049                                   "clearing orphan list.\n");
2050                 es->s_last_orphan = 0;
2051                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2052                 return;
2053         }
2054
2055         if (s_flags & MS_RDONLY) {
2056                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2057                 sb->s_flags &= ~MS_RDONLY;
2058         }
2059 #ifdef CONFIG_QUOTA
2060         /* Needed for iput() to work correctly and not trash data */
2061         sb->s_flags |= MS_ACTIVE;
2062         /* Turn on quotas so that they are updated correctly */
2063         for (i = 0; i < MAXQUOTAS; i++) {
2064                 if (EXT4_SB(sb)->s_qf_names[i]) {
2065                         int ret = ext4_quota_on_mount(sb, i);
2066                         if (ret < 0)
2067                                 ext4_msg(sb, KERN_ERR,
2068                                         "Cannot turn on journaled "
2069                                         "quota: error %d", ret);
2070                 }
2071         }
2072 #endif
2073
2074         while (es->s_last_orphan) {
2075                 struct inode *inode;
2076
2077                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2078                 if (IS_ERR(inode)) {
2079                         es->s_last_orphan = 0;
2080                         break;
2081                 }
2082
2083                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2084                 dquot_initialize(inode);
2085                 if (inode->i_nlink) {
2086                         ext4_msg(sb, KERN_DEBUG,
2087                                 "%s: truncating inode %lu to %lld bytes",
2088                                 __func__, inode->i_ino, inode->i_size);
2089                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2090                                   inode->i_ino, inode->i_size);
2091                         ext4_truncate(inode);
2092                         nr_truncates++;
2093                 } else {
2094                         ext4_msg(sb, KERN_DEBUG,
2095                                 "%s: deleting unreferenced inode %lu",
2096                                 __func__, inode->i_ino);
2097                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2098                                   inode->i_ino);
2099                         nr_orphans++;
2100                 }
2101                 iput(inode);  /* The delete magic happens here! */
2102         }
2103
2104 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2105
2106         if (nr_orphans)
2107                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2108                        PLURAL(nr_orphans));
2109         if (nr_truncates)
2110                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2111                        PLURAL(nr_truncates));
2112 #ifdef CONFIG_QUOTA
2113         /* Turn quotas off */
2114         for (i = 0; i < MAXQUOTAS; i++) {
2115                 if (sb_dqopt(sb)->files[i])
2116                         dquot_quota_off(sb, i);
2117         }
2118 #endif
2119         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2120 }
2121
2122 /*
2123  * Maximal extent format file size.
2124  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2125  * extent format containers, within a sector_t, and within i_blocks
2126  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2127  * so that won't be a limiting factor.
2128  *
2129  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2130  */
2131 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2132 {
2133         loff_t res;
2134         loff_t upper_limit = MAX_LFS_FILESIZE;
2135
2136         /* small i_blocks in vfs inode? */
2137         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2138                 /*
2139                  * CONFIG_LBDAF is not enabled implies the inode
2140                  * i_block represent total blocks in 512 bytes
2141                  * 32 == size of vfs inode i_blocks * 8
2142                  */
2143                 upper_limit = (1LL << 32) - 1;
2144
2145                 /* total blocks in file system block size */
2146                 upper_limit >>= (blkbits - 9);
2147                 upper_limit <<= blkbits;
2148         }
2149
2150         /* 32-bit extent-start container, ee_block */
2151         res = 1LL << 32;
2152         res <<= blkbits;
2153         res -= 1;
2154
2155         /* Sanity check against vm- & vfs- imposed limits */
2156         if (res > upper_limit)
2157                 res = upper_limit;
2158
2159         return res;
2160 }
2161
2162 /*
2163  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2164  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2165  * We need to be 1 filesystem block less than the 2^48 sector limit.
2166  */
2167 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2168 {
2169         loff_t res = EXT4_NDIR_BLOCKS;
2170         int meta_blocks;
2171         loff_t upper_limit;
2172         /* This is calculated to be the largest file size for a dense, block
2173          * mapped file such that the file's total number of 512-byte sectors,
2174          * including data and all indirect blocks, does not exceed (2^48 - 1).
2175          *
2176          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2177          * number of 512-byte sectors of the file.
2178          */
2179
2180         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2181                 /*
2182                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2183                  * the inode i_block field represents total file blocks in
2184                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2185                  */
2186                 upper_limit = (1LL << 32) - 1;
2187
2188                 /* total blocks in file system block size */
2189                 upper_limit >>= (bits - 9);
2190
2191         } else {
2192                 /*
2193                  * We use 48 bit ext4_inode i_blocks
2194                  * With EXT4_HUGE_FILE_FL set the i_blocks
2195                  * represent total number of blocks in
2196                  * file system block size
2197                  */
2198                 upper_limit = (1LL << 48) - 1;
2199
2200         }
2201
2202         /* indirect blocks */
2203         meta_blocks = 1;
2204         /* double indirect blocks */
2205         meta_blocks += 1 + (1LL << (bits-2));
2206         /* tripple indirect blocks */
2207         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2208
2209         upper_limit -= meta_blocks;
2210         upper_limit <<= bits;
2211
2212         res += 1LL << (bits-2);
2213         res += 1LL << (2*(bits-2));
2214         res += 1LL << (3*(bits-2));
2215         res <<= bits;
2216         if (res > upper_limit)
2217                 res = upper_limit;
2218
2219         if (res > MAX_LFS_FILESIZE)
2220                 res = MAX_LFS_FILESIZE;
2221
2222         return res;
2223 }
2224
2225 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2226                                    ext4_fsblk_t logical_sb_block, int nr)
2227 {
2228         struct ext4_sb_info *sbi = EXT4_SB(sb);
2229         ext4_group_t bg, first_meta_bg;
2230         int has_super = 0;
2231
2232         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2233
2234         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2235             nr < first_meta_bg)
2236                 return logical_sb_block + nr + 1;
2237         bg = sbi->s_desc_per_block * nr;
2238         if (ext4_bg_has_super(sb, bg))
2239                 has_super = 1;
2240
2241         return (has_super + ext4_group_first_block_no(sb, bg));
2242 }
2243
2244 /**
2245  * ext4_get_stripe_size: Get the stripe size.
2246  * @sbi: In memory super block info
2247  *
2248  * If we have specified it via mount option, then
2249  * use the mount option value. If the value specified at mount time is
2250  * greater than the blocks per group use the super block value.
2251  * If the super block value is greater than blocks per group return 0.
2252  * Allocator needs it be less than blocks per group.
2253  *
2254  */
2255 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2256 {
2257         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2258         unsigned long stripe_width =
2259                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2260
2261         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2262                 return sbi->s_stripe;
2263
2264         if (stripe_width <= sbi->s_blocks_per_group)
2265                 return stripe_width;
2266
2267         if (stride <= sbi->s_blocks_per_group)
2268                 return stride;
2269
2270         return 0;
2271 }
2272
2273 /* sysfs supprt */
2274
2275 struct ext4_attr {
2276         struct attribute attr;
2277         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2278         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2279                          const char *, size_t);
2280         int offset;
2281 };
2282
2283 static int parse_strtoul(const char *buf,
2284                 unsigned long max, unsigned long *value)
2285 {
2286         char *endp;
2287
2288         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2289         endp = skip_spaces(endp);
2290         if (*endp || *value > max)
2291                 return -EINVAL;
2292
2293         return 0;
2294 }
2295
2296 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2297                                               struct ext4_sb_info *sbi,
2298                                               char *buf)
2299 {
2300         return snprintf(buf, PAGE_SIZE, "%llu\n",
2301                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2302 }
2303
2304 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2305                                          struct ext4_sb_info *sbi, char *buf)
2306 {
2307         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2308
2309         if (!sb->s_bdev->bd_part)
2310                 return snprintf(buf, PAGE_SIZE, "0\n");
2311         return snprintf(buf, PAGE_SIZE, "%lu\n",
2312                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2313                          sbi->s_sectors_written_start) >> 1);
2314 }
2315
2316 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2317                                           struct ext4_sb_info *sbi, char *buf)
2318 {
2319         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2320
2321         if (!sb->s_bdev->bd_part)
2322                 return snprintf(buf, PAGE_SIZE, "0\n");
2323         return snprintf(buf, PAGE_SIZE, "%llu\n",
2324                         (unsigned long long)(sbi->s_kbytes_written +
2325                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2326                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2327 }
2328
2329 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2330                                           struct ext4_sb_info *sbi,
2331                                           const char *buf, size_t count)
2332 {
2333         unsigned long t;
2334
2335         if (parse_strtoul(buf, 0x40000000, &t))
2336                 return -EINVAL;
2337
2338         if (!is_power_of_2(t))
2339                 return -EINVAL;
2340
2341         sbi->s_inode_readahead_blks = t;
2342         return count;
2343 }
2344
2345 static ssize_t sbi_ui_show(struct ext4_attr *a,
2346                            struct ext4_sb_info *sbi, char *buf)
2347 {
2348         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2349
2350         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2351 }
2352
2353 static ssize_t sbi_ui_store(struct ext4_attr *a,
2354                             struct ext4_sb_info *sbi,
2355                             const char *buf, size_t count)
2356 {
2357         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2358         unsigned long t;
2359
2360         if (parse_strtoul(buf, 0xffffffff, &t))
2361                 return -EINVAL;
2362         *ui = t;
2363         return count;
2364 }
2365
2366 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2367 static struct ext4_attr ext4_attr_##_name = {                   \
2368         .attr = {.name = __stringify(_name), .mode = _mode },   \
2369         .show   = _show,                                        \
2370         .store  = _store,                                       \
2371         .offset = offsetof(struct ext4_sb_info, _elname),       \
2372 }
2373 #define EXT4_ATTR(name, mode, show, store) \
2374 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2375
2376 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2377 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2378 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2379         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2380 #define ATTR_LIST(name) &ext4_attr_##name.attr
2381
2382 EXT4_RO_ATTR(delayed_allocation_blocks);
2383 EXT4_RO_ATTR(session_write_kbytes);
2384 EXT4_RO_ATTR(lifetime_write_kbytes);
2385 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2386                  inode_readahead_blks_store, s_inode_readahead_blks);
2387 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2388 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2389 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2390 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2391 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2392 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2393 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2394 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2395
2396 static struct attribute *ext4_attrs[] = {
2397         ATTR_LIST(delayed_allocation_blocks),
2398         ATTR_LIST(session_write_kbytes),
2399         ATTR_LIST(lifetime_write_kbytes),
2400         ATTR_LIST(inode_readahead_blks),
2401         ATTR_LIST(inode_goal),
2402         ATTR_LIST(mb_stats),
2403         ATTR_LIST(mb_max_to_scan),
2404         ATTR_LIST(mb_min_to_scan),
2405         ATTR_LIST(mb_order2_req),
2406         ATTR_LIST(mb_stream_req),
2407         ATTR_LIST(mb_group_prealloc),
2408         ATTR_LIST(max_writeback_mb_bump),
2409         NULL,
2410 };
2411
2412 static ssize_t ext4_attr_show(struct kobject *kobj,
2413                               struct attribute *attr, char *buf)
2414 {
2415         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2416                                                 s_kobj);
2417         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2418
2419         return a->show ? a->show(a, sbi, buf) : 0;
2420 }
2421
2422 static ssize_t ext4_attr_store(struct kobject *kobj,
2423                                struct attribute *attr,
2424                                const char *buf, size_t len)
2425 {
2426         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2427                                                 s_kobj);
2428         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2429
2430         return a->store ? a->store(a, sbi, buf, len) : 0;
2431 }
2432
2433 static void ext4_sb_release(struct kobject *kobj)
2434 {
2435         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2436                                                 s_kobj);
2437         complete(&sbi->s_kobj_unregister);
2438 }
2439
2440
2441 static const struct sysfs_ops ext4_attr_ops = {
2442         .show   = ext4_attr_show,
2443         .store  = ext4_attr_store,
2444 };
2445
2446 static struct kobj_type ext4_ktype = {
2447         .default_attrs  = ext4_attrs,
2448         .sysfs_ops      = &ext4_attr_ops,
2449         .release        = ext4_sb_release,
2450 };
2451
2452 /*
2453  * Check whether this filesystem can be mounted based on
2454  * the features present and the RDONLY/RDWR mount requested.
2455  * Returns 1 if this filesystem can be mounted as requested,
2456  * 0 if it cannot be.
2457  */
2458 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2459 {
2460         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2461                 ext4_msg(sb, KERN_ERR,
2462                         "Couldn't mount because of "
2463                         "unsupported optional features (%x)",
2464                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2465                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2466                 return 0;
2467         }
2468
2469         if (readonly)
2470                 return 1;
2471
2472         /* Check that feature set is OK for a read-write mount */
2473         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2474                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2475                          "unsupported optional features (%x)",
2476                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2477                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2478                 return 0;
2479         }
2480         /*
2481          * Large file size enabled file system can only be mounted
2482          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2483          */
2484         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2485                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2486                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2487                                  "cannot be mounted RDWR without "
2488                                  "CONFIG_LBDAF");
2489                         return 0;
2490                 }
2491         }
2492         return 1;
2493 }
2494
2495 /*
2496  * This function is called once a day if we have errors logged
2497  * on the file system
2498  */
2499 static void print_daily_error_info(unsigned long arg)
2500 {
2501         struct super_block *sb = (struct super_block *) arg;
2502         struct ext4_sb_info *sbi;
2503         struct ext4_super_block *es;
2504
2505         sbi = EXT4_SB(sb);
2506         es = sbi->s_es;
2507
2508         if (es->s_error_count)
2509                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2510                          le32_to_cpu(es->s_error_count));
2511         if (es->s_first_error_time) {
2512                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2513                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2514                        (int) sizeof(es->s_first_error_func),
2515                        es->s_first_error_func,
2516                        le32_to_cpu(es->s_first_error_line));
2517                 if (es->s_first_error_ino)
2518                         printk(": inode %u",
2519                                le32_to_cpu(es->s_first_error_ino));
2520                 if (es->s_first_error_block)
2521                         printk(": block %llu", (unsigned long long)
2522                                le64_to_cpu(es->s_first_error_block));
2523                 printk("\n");
2524         }
2525         if (es->s_last_error_time) {
2526                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2527                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2528                        (int) sizeof(es->s_last_error_func),
2529                        es->s_last_error_func,
2530                        le32_to_cpu(es->s_last_error_line));
2531                 if (es->s_last_error_ino)
2532                         printk(": inode %u",
2533                                le32_to_cpu(es->s_last_error_ino));
2534                 if (es->s_last_error_block)
2535                         printk(": block %llu", (unsigned long long)
2536                                le64_to_cpu(es->s_last_error_block));
2537                 printk("\n");
2538         }
2539         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2540 }
2541
2542 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2543                                 __releases(kernel_lock)
2544                                 __acquires(kernel_lock)
2545 {
2546         char *orig_data = kstrdup(data, GFP_KERNEL);
2547         struct buffer_head *bh;
2548         struct ext4_super_block *es = NULL;
2549         struct ext4_sb_info *sbi;
2550         ext4_fsblk_t block;
2551         ext4_fsblk_t sb_block = get_sb_block(&data);
2552         ext4_fsblk_t logical_sb_block;
2553         unsigned long offset = 0;
2554         unsigned long journal_devnum = 0;
2555         unsigned long def_mount_opts;
2556         struct inode *root;
2557         char *cp;
2558         const char *descr;
2559         int ret = -ENOMEM;
2560         int blocksize;
2561         unsigned int db_count;
2562         unsigned int i;
2563         int needs_recovery, has_huge_files;
2564         __u64 blocks_count;
2565         int err;
2566         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2567
2568         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2569         if (!sbi)
2570                 goto out_free_orig;
2571
2572         sbi->s_blockgroup_lock =
2573                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2574         if (!sbi->s_blockgroup_lock) {
2575                 kfree(sbi);
2576                 goto out_free_orig;
2577         }
2578         sb->s_fs_info = sbi;
2579         sbi->s_mount_opt = 0;
2580         sbi->s_resuid = EXT4_DEF_RESUID;
2581         sbi->s_resgid = EXT4_DEF_RESGID;
2582         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2583         sbi->s_sb_block = sb_block;
2584         if (sb->s_bdev->bd_part)
2585                 sbi->s_sectors_written_start =
2586                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
2587
2588         /* Cleanup superblock name */
2589         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2590                 *cp = '!';
2591
2592         ret = -EINVAL;
2593         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2594         if (!blocksize) {
2595                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
2596                 goto out_fail;
2597         }
2598
2599         /*
2600          * The ext4 superblock will not be buffer aligned for other than 1kB
2601          * block sizes.  We need to calculate the offset from buffer start.
2602          */
2603         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2604                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2605                 offset = do_div(logical_sb_block, blocksize);
2606         } else {
2607                 logical_sb_block = sb_block;
2608         }
2609
2610         if (!(bh = sb_bread(sb, logical_sb_block))) {
2611                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
2612                 goto out_fail;
2613         }
2614         /*
2615          * Note: s_es must be initialized as soon as possible because
2616          *       some ext4 macro-instructions depend on its value
2617          */
2618         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2619         sbi->s_es = es;
2620         sb->s_magic = le16_to_cpu(es->s_magic);
2621         if (sb->s_magic != EXT4_SUPER_MAGIC)
2622                 goto cantfind_ext4;
2623         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
2624
2625         /* Set defaults before we parse the mount options */
2626         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2627         if (def_mount_opts & EXT4_DEFM_DEBUG)
2628                 set_opt(sbi->s_mount_opt, DEBUG);
2629         if (def_mount_opts & EXT4_DEFM_BSDGROUPS) {
2630                 ext4_msg(sb, KERN_WARNING, deprecated_msg, "bsdgroups",
2631                         "2.6.38");
2632                 set_opt(sbi->s_mount_opt, GRPID);
2633         }
2634         if (def_mount_opts & EXT4_DEFM_UID16)
2635                 set_opt(sbi->s_mount_opt, NO_UID32);
2636 #ifdef CONFIG_EXT4_FS_XATTR
2637         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2638                 set_opt(sbi->s_mount_opt, XATTR_USER);
2639 #endif
2640 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2641         if (def_mount_opts & EXT4_DEFM_ACL)
2642                 set_opt(sbi->s_mount_opt, POSIX_ACL);
2643 #endif
2644         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2645                 set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2646         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2647                 set_opt(sbi->s_mount_opt, ORDERED_DATA);
2648         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2649                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2650
2651         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2652                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2653         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2654                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2655         else
2656                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2657         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
2658                 set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
2659         if (def_mount_opts & EXT4_DEFM_DISCARD)
2660                 set_opt(sbi->s_mount_opt, DISCARD);
2661
2662         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2663         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2664         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2665         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2666         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2667
2668         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
2669                 set_opt(sbi->s_mount_opt, BARRIER);
2670
2671         /*
2672          * enable delayed allocation by default
2673          * Use -o nodelalloc to turn it off
2674          */
2675         if (!IS_EXT3_SB(sb) &&
2676             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
2677                 set_opt(sbi->s_mount_opt, DELALLOC);
2678
2679         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
2680                            &journal_devnum, &journal_ioprio, NULL, 0)) {
2681                 ext4_msg(sb, KERN_WARNING,
2682                          "failed to parse options in superblock: %s",
2683                          sbi->s_es->s_mount_opts);
2684         }
2685         if (!parse_options((char *) data, sb, &journal_devnum,
2686                            &journal_ioprio, NULL, 0))
2687                 goto failed_mount;
2688
2689         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2690                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
2691
2692         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2693             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2694              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2695              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2696                 ext4_msg(sb, KERN_WARNING,
2697                        "feature flags set on rev 0 fs, "
2698                        "running e2fsck is recommended");
2699
2700         /*
2701          * Check feature flags regardless of the revision level, since we
2702          * previously didn't change the revision level when setting the flags,
2703          * so there is a chance incompat flags are set on a rev 0 filesystem.
2704          */
2705         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
2706                 goto failed_mount;
2707
2708         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2709
2710         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2711             blocksize > EXT4_MAX_BLOCK_SIZE) {
2712                 ext4_msg(sb, KERN_ERR,
2713                        "Unsupported filesystem blocksize %d", blocksize);
2714                 goto failed_mount;
2715         }
2716
2717         if (sb->s_blocksize != blocksize) {
2718                 /* Validate the filesystem blocksize */
2719                 if (!sb_set_blocksize(sb, blocksize)) {
2720                         ext4_msg(sb, KERN_ERR, "bad block size %d",
2721                                         blocksize);
2722                         goto failed_mount;
2723                 }
2724
2725                 brelse(bh);
2726                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2727                 offset = do_div(logical_sb_block, blocksize);
2728                 bh = sb_bread(sb, logical_sb_block);
2729                 if (!bh) {
2730                         ext4_msg(sb, KERN_ERR,
2731                                "Can't read superblock on 2nd try");
2732                         goto failed_mount;
2733                 }
2734                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2735                 sbi->s_es = es;
2736                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2737                         ext4_msg(sb, KERN_ERR,
2738                                "Magic mismatch, very weird!");
2739                         goto failed_mount;
2740                 }
2741         }
2742
2743         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2744                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2745         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2746                                                       has_huge_files);
2747         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2748
2749         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2750                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2751                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2752         } else {
2753                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2754                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2755                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2756                     (!is_power_of_2(sbi->s_inode_size)) ||
2757                     (sbi->s_inode_size > blocksize)) {
2758                         ext4_msg(sb, KERN_ERR,
2759                                "unsupported inode size: %d",
2760                                sbi->s_inode_size);
2761                         goto failed_mount;
2762                 }
2763                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2764                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2765         }
2766
2767         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2768         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2769                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2770                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2771                     !is_power_of_2(sbi->s_desc_size)) {
2772                         ext4_msg(sb, KERN_ERR,
2773                                "unsupported descriptor size %lu",
2774                                sbi->s_desc_size);
2775                         goto failed_mount;
2776                 }
2777         } else
2778                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2779
2780         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2781         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2782         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2783                 goto cantfind_ext4;
2784
2785         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2786         if (sbi->s_inodes_per_block == 0)
2787                 goto cantfind_ext4;
2788         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2789                                         sbi->s_inodes_per_block;
2790         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2791         sbi->s_sbh = bh;
2792         sbi->s_mount_state = le16_to_cpu(es->s_state);
2793         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2794         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2795
2796         for (i = 0; i < 4; i++)
2797                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2798         sbi->s_def_hash_version = es->s_def_hash_version;
2799         i = le32_to_cpu(es->s_flags);
2800         if (i & EXT2_FLAGS_UNSIGNED_HASH)
2801                 sbi->s_hash_unsigned = 3;
2802         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2803 #ifdef __CHAR_UNSIGNED__
2804                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2805                 sbi->s_hash_unsigned = 3;
2806 #else
2807                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2808 #endif
2809                 sb->s_dirt = 1;
2810         }
2811
2812         if (sbi->s_blocks_per_group > blocksize * 8) {
2813                 ext4_msg(sb, KERN_ERR,
2814                        "#blocks per group too big: %lu",
2815                        sbi->s_blocks_per_group);
2816                 goto failed_mount;
2817         }
2818         if (sbi->s_inodes_per_group > blocksize * 8) {
2819                 ext4_msg(sb, KERN_ERR,
2820                        "#inodes per group too big: %lu",
2821                        sbi->s_inodes_per_group);
2822                 goto failed_mount;
2823         }
2824
2825         /*
2826          * Test whether we have more sectors than will fit in sector_t,
2827          * and whether the max offset is addressable by the page cache.
2828          */
2829         if ((ext4_blocks_count(es) >
2830              (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) ||
2831             (ext4_blocks_count(es) >
2832              (pgoff_t)(~0ULL) >> (PAGE_CACHE_SHIFT - sb->s_blocksize_bits))) {
2833                 ext4_msg(sb, KERN_ERR, "filesystem"
2834                          " too large to mount safely on this system");
2835                 if (sizeof(sector_t) < 8)
2836                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
2837                 ret = -EFBIG;
2838                 goto failed_mount;
2839         }
2840
2841         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2842                 goto cantfind_ext4;
2843
2844         /* check blocks count against device size */
2845         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2846         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
2847                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
2848                        "exceeds size of device (%llu blocks)",
2849                        ext4_blocks_count(es), blocks_count);
2850                 goto failed_mount;
2851         }
2852
2853         /*
2854          * It makes no sense for the first data block to be beyond the end
2855          * of the filesystem.
2856          */
2857         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2858                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
2859                          "block %u is beyond end of filesystem (%llu)",
2860                          le32_to_cpu(es->s_first_data_block),
2861                          ext4_blocks_count(es));
2862                 goto failed_mount;
2863         }
2864         blocks_count = (ext4_blocks_count(es) -
2865                         le32_to_cpu(es->s_first_data_block) +
2866                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2867         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2868         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2869                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
2870                        "(block count %llu, first data block %u, "
2871                        "blocks per group %lu)", sbi->s_groups_count,
2872                        ext4_blocks_count(es),
2873                        le32_to_cpu(es->s_first_data_block),
2874                        EXT4_BLOCKS_PER_GROUP(sb));
2875                 goto failed_mount;
2876         }
2877         sbi->s_groups_count = blocks_count;
2878         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
2879                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
2880         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2881                    EXT4_DESC_PER_BLOCK(sb);
2882         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2883                                     GFP_KERNEL);
2884         if (sbi->s_group_desc == NULL) {
2885                 ext4_msg(sb, KERN_ERR, "not enough memory");
2886                 goto failed_mount;
2887         }
2888
2889 #ifdef CONFIG_PROC_FS
2890         if (ext4_proc_root)
2891                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2892 #endif
2893
2894         bgl_lock_init(sbi->s_blockgroup_lock);
2895
2896         for (i = 0; i < db_count; i++) {
2897                 block = descriptor_loc(sb, logical_sb_block, i);
2898                 sbi->s_group_desc[i] = sb_bread(sb, block);
2899                 if (!sbi->s_group_desc[i]) {
2900                         ext4_msg(sb, KERN_ERR,
2901                                "can't read group descriptor %d", i);
2902                         db_count = i;
2903                         goto failed_mount2;
2904                 }
2905         }
2906         if (!ext4_check_descriptors(sb)) {
2907                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
2908                 goto failed_mount2;
2909         }
2910         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2911                 if (!ext4_fill_flex_info(sb)) {
2912                         ext4_msg(sb, KERN_ERR,
2913                                "unable to initialize "
2914                                "flex_bg meta info!");
2915                         goto failed_mount2;
2916                 }
2917
2918         sbi->s_gdb_count = db_count;
2919         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2920         spin_lock_init(&sbi->s_next_gen_lock);
2921
2922         sbi->s_stripe = ext4_get_stripe_size(sbi);
2923         sbi->s_max_writeback_mb_bump = 128;
2924
2925         /*
2926          * set up enough so that it can read an inode
2927          */
2928         if (!test_opt(sb, NOLOAD) &&
2929             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
2930                 sb->s_op = &ext4_sops;
2931         else
2932                 sb->s_op = &ext4_nojournal_sops;
2933         sb->s_export_op = &ext4_export_ops;
2934         sb->s_xattr = ext4_xattr_handlers;
2935 #ifdef CONFIG_QUOTA
2936         sb->s_qcop = &ext4_qctl_operations;
2937         sb->dq_op = &ext4_quota_operations;
2938 #endif
2939         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2940         mutex_init(&sbi->s_orphan_lock);
2941         mutex_init(&sbi->s_resize_lock);
2942
2943         sb->s_root = NULL;
2944
2945         needs_recovery = (es->s_last_orphan != 0 ||
2946                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2947                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2948
2949         /*
2950          * The first inode we look at is the journal inode.  Don't try
2951          * root first: it may be modified in the journal!
2952          */
2953         if (!test_opt(sb, NOLOAD) &&
2954             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2955                 if (ext4_load_journal(sb, es, journal_devnum))
2956                         goto failed_mount3;
2957         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2958               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2959                 ext4_msg(sb, KERN_ERR, "required journal recovery "
2960                        "suppressed and not mounted read-only");
2961                 goto failed_mount_wq;
2962         } else {
2963                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2964                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2965                 sbi->s_journal = NULL;
2966                 needs_recovery = 0;
2967                 goto no_journal;
2968         }
2969
2970         if (ext4_blocks_count(es) > 0xffffffffULL &&
2971             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2972                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2973                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
2974                 goto failed_mount_wq;
2975         }
2976
2977         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2978                 jbd2_journal_set_features(sbi->s_journal,
2979                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2980                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2981         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2982                 jbd2_journal_set_features(sbi->s_journal,
2983                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2984                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2985                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2986         } else {
2987                 jbd2_journal_clear_features(sbi->s_journal,
2988                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2989                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2990         }
2991
2992         /* We have now updated the journal if required, so we can
2993          * validate the data journaling mode. */
2994         switch (test_opt(sb, DATA_FLAGS)) {
2995         case 0:
2996                 /* No mode set, assume a default based on the journal
2997                  * capabilities: ORDERED_DATA if the journal can
2998                  * cope, else JOURNAL_DATA
2999                  */
3000                 if (jbd2_journal_check_available_features
3001                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3002                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
3003                 else
3004                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
3005                 break;
3006
3007         case EXT4_MOUNT_ORDERED_DATA:
3008         case EXT4_MOUNT_WRITEBACK_DATA:
3009                 if (!jbd2_journal_check_available_features
3010                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3011                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3012                                "requested data journaling mode");
3013                         goto failed_mount_wq;
3014                 }
3015         default:
3016                 break;
3017         }
3018         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3019
3020 no_journal:
3021         err = percpu_counter_init(&sbi->s_freeblocks_counter,
3022                                   ext4_count_free_blocks(sb));
3023         if (!err)
3024                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3025                                           ext4_count_free_inodes(sb));
3026         if (!err)
3027                 err = percpu_counter_init(&sbi->s_dirs_counter,
3028                                           ext4_count_dirs(sb));
3029         if (!err)
3030                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
3031         if (err) {
3032                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3033                 goto failed_mount_wq;
3034         }
3035
3036         EXT4_SB(sb)->dio_unwritten_wq = create_workqueue("ext4-dio-unwritten");
3037         if (!EXT4_SB(sb)->dio_unwritten_wq) {
3038                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3039                 goto failed_mount_wq;
3040         }
3041
3042         /*
3043          * The jbd2_journal_load will have done any necessary log recovery,
3044          * so we can safely mount the rest of the filesystem now.
3045          */
3046
3047         root = ext4_iget(sb, EXT4_ROOT_INO);
3048         if (IS_ERR(root)) {
3049                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3050                 ret = PTR_ERR(root);
3051                 goto failed_mount4;
3052         }
3053         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3054                 iput(root);
3055                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3056                 goto failed_mount4;
3057         }
3058         sb->s_root = d_alloc_root(root);
3059         if (!sb->s_root) {
3060                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3061                 iput(root);
3062                 ret = -ENOMEM;
3063                 goto failed_mount4;
3064         }
3065
3066         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
3067
3068         /* determine the minimum size of new large inodes, if present */
3069         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3070                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3071                                                      EXT4_GOOD_OLD_INODE_SIZE;
3072                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3073                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3074                         if (sbi->s_want_extra_isize <
3075                             le16_to_cpu(es->s_want_extra_isize))
3076                                 sbi->s_want_extra_isize =
3077                                         le16_to_cpu(es->s_want_extra_isize);
3078                         if (sbi->s_want_extra_isize <
3079                             le16_to_cpu(es->s_min_extra_isize))
3080                                 sbi->s_want_extra_isize =
3081                                         le16_to_cpu(es->s_min_extra_isize);
3082                 }
3083         }
3084         /* Check if enough inode space is available */
3085         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3086                                                         sbi->s_inode_size) {
3087                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3088                                                        EXT4_GOOD_OLD_INODE_SIZE;
3089                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3090                          "available");
3091         }
3092
3093         if (test_opt(sb, DELALLOC) &&
3094             (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
3095                 ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
3096                          "requested data journaling mode");
3097                 clear_opt(sbi->s_mount_opt, DELALLOC);
3098         }
3099         if (test_opt(sb, DIOREAD_NOLOCK)) {
3100                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3101                         ext4_msg(sb, KERN_WARNING, "Ignoring dioread_nolock "
3102                                 "option - requested data journaling mode");
3103                         clear_opt(sbi->s_mount_opt, DIOREAD_NOLOCK);
3104                 }
3105                 if (sb->s_blocksize < PAGE_SIZE) {
3106                         ext4_msg(sb, KERN_WARNING, "Ignoring dioread_nolock "
3107                                 "option - block size is too small");
3108                         clear_opt(sbi->s_mount_opt, DIOREAD_NOLOCK);
3109                 }
3110         }
3111
3112         err = ext4_setup_system_zone(sb);
3113         if (err) {
3114                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3115                          "zone (%d)", err);
3116                 goto failed_mount4;
3117         }
3118
3119         ext4_ext_init(sb);
3120         err = ext4_mb_init(sb, needs_recovery);
3121         if (err) {
3122                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3123                          err);
3124                 goto failed_mount4;
3125         }
3126
3127         sbi->s_kobj.kset = ext4_kset;
3128         init_completion(&sbi->s_kobj_unregister);
3129         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3130                                    "%s", sb->s_id);
3131         if (err) {
3132                 ext4_mb_release(sb);
3133                 ext4_ext_release(sb);
3134                 goto failed_mount4;
3135         };
3136
3137         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3138         ext4_orphan_cleanup(sb, es);
3139         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3140         if (needs_recovery) {
3141                 ext4_msg(sb, KERN_INFO, "recovery complete");
3142                 ext4_mark_recovery_complete(sb, es);
3143         }
3144         if (EXT4_SB(sb)->s_journal) {
3145                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3146                         descr = " journalled data mode";
3147                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3148                         descr = " ordered data mode";
3149                 else
3150                         descr = " writeback data mode";
3151         } else
3152                 descr = "out journal";
3153
3154         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3155                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3156                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3157
3158         init_timer(&sbi->s_err_report);
3159         sbi->s_err_report.function = print_daily_error_info;
3160         sbi->s_err_report.data = (unsigned long) sb;
3161         if (es->s_error_count)
3162                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3163
3164         kfree(orig_data);
3165         return 0;
3166
3167 cantfind_ext4:
3168         if (!silent)
3169                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3170         goto failed_mount;
3171
3172 failed_mount4:
3173         ext4_msg(sb, KERN_ERR, "mount failed");
3174         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3175 failed_mount_wq:
3176         ext4_release_system_zone(sb);
3177         if (sbi->s_journal) {
3178                 jbd2_journal_destroy(sbi->s_journal);
3179                 sbi->s_journal = NULL;
3180         }
3181         percpu_counter_destroy(&sbi->s_freeblocks_counter);
3182         percpu_counter_destroy(&sbi->s_freeinodes_counter);
3183         percpu_counter_destroy(&sbi->s_dirs_counter);
3184         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
3185 failed_mount3:
3186         if (sbi->s_flex_groups) {
3187                 if (is_vmalloc_addr(sbi->s_flex_groups))
3188                         vfree(sbi->s_flex_groups);
3189                 else
3190                         kfree(sbi->s_flex_groups);
3191         }
3192 failed_mount2:
3193         for (i = 0; i < db_count; i++)
3194                 brelse(sbi->s_group_desc[i]);
3195         kfree(sbi->s_group_desc);
3196 failed_mount:
3197         if (sbi->s_proc) {
3198                 remove_proc_entry(sb->s_id, ext4_proc_root);
3199         }
3200 #ifdef CONFIG_QUOTA
3201         for (i = 0; i < MAXQUOTAS; i++)
3202                 kfree(sbi->s_qf_names[i]);
3203 #endif
3204         ext4_blkdev_remove(sbi);
3205         brelse(bh);
3206 out_fail:
3207         sb->s_fs_info = NULL;
3208         kfree(sbi->s_blockgroup_lock);
3209         kfree(sbi);
3210 out_free_orig:
3211         kfree(orig_data);
3212         return ret;
3213 }
3214
3215 /*
3216  * Setup any per-fs journal parameters now.  We'll do this both on
3217  * initial mount, once the journal has been initialised but before we've
3218  * done any recovery; and again on any subsequent remount.
3219  */
3220 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3221 {
3222         struct ext4_sb_info *sbi = EXT4_SB(sb);
3223
3224         journal->j_commit_interval = sbi->s_commit_interval;
3225         journal->j_min_batch_time = sbi->s_min_batch_time;
3226         journal->j_max_batch_time = sbi->s_max_batch_time;
3227
3228         write_lock(&journal->j_state_lock);
3229         if (test_opt(sb, BARRIER))
3230                 journal->j_flags |= JBD2_BARRIER;
3231         else
3232                 journal->j_flags &= ~JBD2_BARRIER;
3233         if (test_opt(sb, DATA_ERR_ABORT))
3234                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3235         else
3236                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3237         write_unlock(&journal->j_state_lock);
3238 }
3239
3240 static journal_t *ext4_get_journal(struct super_block *sb,
3241                                    unsigned int journal_inum)
3242 {
3243         struct inode *journal_inode;
3244         journal_t *journal;
3245
3246         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3247
3248         /* First, test for the existence of a valid inode on disk.  Bad
3249          * things happen if we iget() an unused inode, as the subsequent
3250          * iput() will try to delete it. */
3251
3252         journal_inode = ext4_iget(sb, journal_inum);
3253         if (IS_ERR(journal_inode)) {
3254                 ext4_msg(sb, KERN_ERR, "no journal found");
3255                 return NULL;
3256         }
3257         if (!journal_inode->i_nlink) {
3258                 make_bad_inode(journal_inode);
3259                 iput(journal_inode);
3260                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3261                 return NULL;
3262         }
3263
3264         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3265                   journal_inode, journal_inode->i_size);
3266         if (!S_ISREG(journal_inode->i_mode)) {
3267                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
3268                 iput(journal_inode);
3269                 return NULL;
3270         }
3271
3272         journal = jbd2_journal_init_inode(journal_inode);
3273         if (!journal) {
3274                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3275                 iput(journal_inode);
3276                 return NULL;
3277         }
3278         journal->j_private = sb;
3279         ext4_init_journal_params(sb, journal);
3280         return journal;
3281 }
3282
3283 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3284                                        dev_t j_dev)
3285 {
3286         struct buffer_head *bh;
3287         journal_t *journal;
3288         ext4_fsblk_t start;
3289         ext4_fsblk_t len;
3290         int hblock, blocksize;
3291         ext4_fsblk_t sb_block;
3292         unsigned long offset;
3293         struct ext4_super_block *es;
3294         struct block_device *bdev;
3295
3296         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3297
3298         bdev = ext4_blkdev_get(j_dev, sb);
3299         if (bdev == NULL)
3300                 return NULL;
3301
3302         if (bd_claim(bdev, sb)) {
3303                 ext4_msg(sb, KERN_ERR,
3304                         "failed to claim external journal device");
3305                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
3306                 return NULL;
3307         }
3308
3309         blocksize = sb->s_blocksize;
3310         hblock = bdev_logical_block_size(bdev);
3311         if (blocksize < hblock) {
3312                 ext4_msg(sb, KERN_ERR,
3313                         "blocksize too small for journal device");
3314                 goto out_bdev;
3315         }
3316
3317         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3318         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3319         set_blocksize(bdev, blocksize);
3320         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3321                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3322                        "external journal");
3323                 goto out_bdev;
3324         }
3325
3326         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3327         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3328             !(le32_to_cpu(es->s_feature_incompat) &
3329               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3330                 ext4_msg(sb, KERN_ERR, "external journal has "
3331                                         "bad superblock");
3332                 brelse(bh);
3333                 goto out_bdev;
3334         }
3335
3336         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3337                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3338                 brelse(bh);
3339                 goto out_bdev;
3340         }
3341
3342         len = ext4_blocks_count(es);
3343         start = sb_block + 1;
3344         brelse(bh);     /* we're done with the superblock */
3345
3346         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3347                                         start, len, blocksize);
3348         if (!journal) {
3349                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
3350                 goto out_bdev;
3351         }
3352         journal->j_private = sb;
3353         ll_rw_block(READ, 1, &journal->j_sb_buffer);
3354         wait_on_buffer(journal->j_sb_buffer);
3355         if (!buffer_uptodate(journal->j_sb_buffer)) {
3356                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3357                 goto out_journal;
3358         }
3359         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3360                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
3361                                         "user (unsupported) - %d",
3362                         be32_to_cpu(journal->j_superblock->s_nr_users));
3363                 goto out_journal;
3364         }
3365         EXT4_SB(sb)->journal_bdev = bdev;
3366         ext4_init_journal_params(sb, journal);
3367         return journal;
3368
3369 out_journal:
3370         jbd2_journal_destroy(journal);
3371 out_bdev:
3372         ext4_blkdev_put(bdev);
3373         return NULL;
3374 }
3375
3376 static int ext4_load_journal(struct super_block *sb,
3377                              struct ext4_super_block *es,
3378                              unsigned long journal_devnum)
3379 {
3380         journal_t *journal;
3381         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3382         dev_t journal_dev;
3383         int err = 0;
3384         int really_read_only;
3385
3386         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3387
3388         if (journal_devnum &&
3389             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3390                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3391                         "numbers have changed");
3392                 journal_dev = new_decode_dev(journal_devnum);
3393         } else
3394                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3395
3396         really_read_only = bdev_read_only(sb->s_bdev);
3397
3398         /*
3399          * Are we loading a blank journal or performing recovery after a
3400          * crash?  For recovery, we need to check in advance whether we
3401          * can get read-write access to the device.
3402          */
3403         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3404                 if (sb->s_flags & MS_RDONLY) {
3405                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
3406                                         "required on readonly filesystem");
3407                         if (really_read_only) {
3408                                 ext4_msg(sb, KERN_ERR, "write access "
3409                                         "unavailable, cannot proceed");
3410                                 return -EROFS;
3411                         }
3412                         ext4_msg(sb, KERN_INFO, "write access will "
3413                                "be enabled during recovery");
3414                 }
3415         }
3416
3417         if (journal_inum && journal_dev) {
3418                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3419                        "and inode journals!");
3420                 return -EINVAL;
3421         }
3422
3423         if (journal_inum) {
3424                 if (!(journal = ext4_get_journal(sb, journal_inum)))
3425                         return -EINVAL;
3426         } else {
3427                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3428                         return -EINVAL;
3429         }
3430
3431         if (!(journal->j_flags & JBD2_BARRIER))
3432                 ext4_msg(sb, KERN_INFO, "barriers disabled");
3433
3434         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3435                 err = jbd2_journal_update_format(journal);
3436                 if (err)  {
3437                         ext4_msg(sb, KERN_ERR, "error updating journal");
3438                         jbd2_journal_destroy(journal);
3439                         return err;
3440                 }
3441         }
3442
3443         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3444                 err = jbd2_journal_wipe(journal, !really_read_only);
3445         if (!err) {
3446                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
3447                 if (save)
3448                         memcpy(save, ((char *) es) +
3449                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
3450                 err = jbd2_journal_load(journal);
3451                 if (save)
3452                         memcpy(((char *) es) + EXT4_S_ERR_START,
3453                                save, EXT4_S_ERR_LEN);
3454                 kfree(save);
3455         }
3456
3457         if (err) {
3458                 ext4_msg(sb, KERN_ERR, "error loading journal");
3459                 jbd2_journal_destroy(journal);
3460                 return err;
3461         }
3462
3463         EXT4_SB(sb)->s_journal = journal;
3464         ext4_clear_journal_err(sb, es);
3465
3466         if (journal_devnum &&
3467             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3468                 es->s_journal_dev = cpu_to_le32(journal_devnum);
3469
3470                 /* Make sure we flush the recovery flag to disk. */
3471                 ext4_commit_super(sb, 1);
3472         }
3473
3474         return 0;
3475 }
3476
3477 static int ext4_commit_super(struct super_block *sb, int sync)
3478 {
3479         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3480         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3481         int error = 0;
3482
3483         if (!sbh)
3484                 return error;
3485         if (buffer_write_io_error(sbh)) {
3486                 /*
3487                  * Oh, dear.  A previous attempt to write the
3488                  * superblock failed.  This could happen because the
3489                  * USB device was yanked out.  Or it could happen to
3490                  * be a transient write error and maybe the block will
3491                  * be remapped.  Nothing we can do but to retry the
3492                  * write and hope for the best.
3493                  */
3494                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
3495                        "superblock detected");
3496                 clear_buffer_write_io_error(sbh);
3497                 set_buffer_uptodate(sbh);
3498         }
3499         /*
3500          * If the file system is mounted read-only, don't update the
3501          * superblock write time.  This avoids updating the superblock
3502          * write time when we are mounting the root file system
3503          * read/only but we need to replay the journal; at that point,
3504          * for people who are east of GMT and who make their clock
3505          * tick in localtime for Windows bug-for-bug compatibility,
3506          * the clock is set in the future, and this will cause e2fsck
3507          * to complain and force a full file system check.
3508          */
3509         if (!(sb->s_flags & MS_RDONLY))
3510                 es->s_wtime = cpu_to_le32(get_seconds());
3511         if (sb->s_bdev->bd_part)
3512                 es->s_kbytes_written =
3513                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
3514                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3515                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
3516         else
3517                 es->s_kbytes_written =
3518                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
3519         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3520                                         &EXT4_SB(sb)->s_freeblocks_counter));
3521         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
3522                                         &EXT4_SB(sb)->s_freeinodes_counter));
3523         sb->s_dirt = 0;
3524         BUFFER_TRACE(sbh, "marking dirty");
3525         mark_buffer_dirty(sbh);
3526         if (sync) {
3527                 error = sync_dirty_buffer(sbh);
3528                 if (error)
3529                         return error;
3530
3531                 error = buffer_write_io_error(sbh);
3532                 if (error) {
3533                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
3534                                "superblock");
3535                         clear_buffer_write_io_error(sbh);
3536                         set_buffer_uptodate(sbh);
3537                 }
3538         }
3539         return error;
3540 }
3541
3542 /*
3543  * Have we just finished recovery?  If so, and if we are mounting (or
3544  * remounting) the filesystem readonly, then we will end up with a
3545  * consistent fs on disk.  Record that fact.
3546  */
3547 static void ext4_mark_recovery_complete(struct super_block *sb,
3548                                         struct ext4_super_block *es)
3549 {
3550         journal_t *journal = EXT4_SB(sb)->s_journal;
3551
3552         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3553                 BUG_ON(journal != NULL);
3554                 return;
3555         }
3556         jbd2_journal_lock_updates(journal);
3557         if (jbd2_journal_flush(journal) < 0)
3558                 goto out;
3559
3560         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
3561             sb->s_flags & MS_RDONLY) {
3562                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3563                 ext4_commit_super(sb, 1);
3564         }
3565
3566 out:
3567         jbd2_journal_unlock_updates(journal);
3568 }
3569
3570 /*
3571  * If we are mounting (or read-write remounting) a filesystem whose journal
3572  * has recorded an error from a previous lifetime, move that error to the
3573  * main filesystem now.
3574  */
3575 static void ext4_clear_journal_err(struct super_block *sb,
3576                                    struct ext4_super_block *es)
3577 {
3578         journal_t *journal;
3579         int j_errno;
3580         const char *errstr;
3581
3582         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3583
3584         journal = EXT4_SB(sb)->s_journal;
3585
3586         /*
3587          * Now check for any error status which may have been recorded in the
3588          * journal by a prior ext4_error() or ext4_abort()
3589          */
3590
3591         j_errno = jbd2_journal_errno(journal);
3592         if (j_errno) {
3593                 char nbuf[16];
3594
3595                 errstr = ext4_decode_error(sb, j_errno, nbuf);
3596                 ext4_warning(sb, "Filesystem error recorded "
3597                              "from previous mount: %s", errstr);
3598                 ext4_warning(sb, "Marking fs in need of filesystem check.");
3599
3600                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3601                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3602                 ext4_commit_super(sb, 1);
3603
3604                 jbd2_journal_clear_err(journal);
3605         }
3606 }
3607
3608 /*
3609  * Force the running and committing transactions to commit,
3610  * and wait on the commit.
3611  */
3612 int ext4_force_commit(struct super_block *sb)
3613 {
3614         journal_t *journal;
3615         int ret = 0;
3616
3617         if (sb->s_flags & MS_RDONLY)
3618                 return 0;
3619
3620         journal = EXT4_SB(sb)->s_journal;
3621         if (journal) {
3622                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
3623                 ret = ext4_journal_force_commit(journal);
3624         }
3625
3626         return ret;
3627 }
3628
3629 static void ext4_write_super(struct super_block *sb)
3630 {
3631         lock_super(sb);
3632         ext4_commit_super(sb, 1);
3633         unlock_super(sb);
3634 }
3635
3636 static int ext4_sync_fs(struct super_block *sb, int wait)
3637 {
3638         int ret = 0;
3639         tid_t target;
3640         struct ext4_sb_info *sbi = EXT4_SB(sb);
3641
3642         trace_ext4_sync_fs(sb, wait);
3643         flush_workqueue(sbi->dio_unwritten_wq);
3644         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
3645                 if (wait)
3646                         jbd2_log_wait_commit(sbi->s_journal, target);
3647         }
3648         return ret;
3649 }
3650
3651 /*
3652  * LVM calls this function before a (read-only) snapshot is created.  This
3653  * gives us a chance to flush the journal completely and mark the fs clean.
3654  */
3655 static int ext4_freeze(struct super_block *sb)
3656 {
3657         int error = 0;
3658         journal_t *journal;
3659
3660         if (sb->s_flags & MS_RDONLY)
3661                 return 0;
3662
3663         journal = EXT4_SB(sb)->s_journal;
3664
3665         /* Now we set up the journal barrier. */
3666         jbd2_journal_lock_updates(journal);
3667
3668         /*
3669          * Don't clear the needs_recovery flag if we failed to flush
3670          * the journal.
3671          */
3672         error = jbd2_journal_flush(journal);
3673         if (error < 0)
3674                 goto out;
3675
3676         /* Journal blocked and flushed, clear needs_recovery flag. */
3677         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3678         error = ext4_commit_super(sb, 1);
3679 out:
3680         /* we rely on s_frozen to stop further updates */
3681         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3682         return error;
3683 }
3684
3685 /*
3686  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3687  * flag here, even though the filesystem is not technically dirty yet.
3688  */
3689 static int ext4_unfreeze(struct super_block *sb)
3690 {
3691         if (sb->s_flags & MS_RDONLY)
3692                 return 0;
3693
3694         lock_super(sb);
3695         /* Reset the needs_recovery flag before the fs is unlocked. */
3696         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3697         ext4_commit_super(sb, 1);
3698         unlock_super(sb);
3699         return 0;
3700 }
3701
3702 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3703 {
3704         struct ext4_super_block *es;
3705         struct ext4_sb_info *sbi = EXT4_SB(sb);
3706         ext4_fsblk_t n_blocks_count = 0;
3707         unsigned long old_sb_flags;
3708         struct ext4_mount_options old_opts;
3709         int enable_quota = 0;
3710         ext4_group_t g;
3711         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3712         int err;
3713 #ifdef CONFIG_QUOTA
3714         int i;
3715 #endif
3716         char *orig_data = kstrdup(data, GFP_KERNEL);
3717
3718         /* Store the original options */
3719         lock_super(sb);
3720         old_sb_flags = sb->s_flags;
3721         old_opts.s_mount_opt = sbi->s_mount_opt;
3722         old_opts.s_resuid = sbi->s_resuid;
3723         old_opts.s_resgid = sbi->s_resgid;
3724         old_opts.s_commit_interval = sbi->s_commit_interval;
3725         old_opts.s_min_batch_time = sbi->s_min_batch_time;
3726         old_opts.s_max_batch_time = sbi->s_max_batch_time;
3727 #ifdef CONFIG_QUOTA
3728         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3729         for (i = 0; i < MAXQUOTAS; i++)
3730                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3731 #endif
3732         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3733                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3734
3735         /*
3736          * Allow the "check" option to be passed as a remount option.
3737          */
3738         if (!parse_options(data, sb, NULL, &journal_ioprio,
3739                            &n_blocks_count, 1)) {
3740                 err = -EINVAL;
3741                 goto restore_opts;
3742         }
3743
3744         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
3745                 ext4_abort(sb, "Abort forced by user");
3746
3747         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3748                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3749
3750         es = sbi->s_es;
3751
3752         if (sbi->s_journal) {
3753                 ext4_init_journal_params(sb, sbi->s_journal);
3754                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3755         }
3756
3757         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3758                 n_blocks_count > ext4_blocks_count(es)) {
3759                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
3760                         err = -EROFS;
3761                         goto restore_opts;
3762                 }
3763
3764                 if (*flags & MS_RDONLY) {
3765                         err = dquot_suspend(sb, -1);
3766                         if (err < 0)
3767                                 goto restore_opts;
3768
3769                         /*
3770                          * First of all, the unconditional stuff we have to do
3771                          * to disable replay of the journal when we next remount
3772                          */
3773                         sb->s_flags |= MS_RDONLY;
3774
3775                         /*
3776                          * OK, test if we are remounting a valid rw partition
3777                          * readonly, and if so set the rdonly flag and then
3778                          * mark the partition as valid again.
3779                          */
3780                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3781                             (sbi->s_mount_state & EXT4_VALID_FS))
3782                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3783
3784                         if (sbi->s_journal)
3785                                 ext4_mark_recovery_complete(sb, es);
3786                 } else {
3787                         /* Make sure we can mount this feature set readwrite */
3788                         if (!ext4_feature_set_ok(sb, 0)) {
3789                                 err = -EROFS;
3790                                 goto restore_opts;
3791                         }
3792                         /*
3793                          * Make sure the group descriptor checksums
3794                          * are sane.  If they aren't, refuse to remount r/w.
3795                          */
3796                         for (g = 0; g < sbi->s_groups_count; g++) {
3797                                 struct ext4_group_desc *gdp =
3798                                         ext4_get_group_desc(sb, g, NULL);
3799
3800                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3801                                         ext4_msg(sb, KERN_ERR,
3802                "ext4_remount: Checksum for group %u failed (%u!=%u)",
3803                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3804                                                le16_to_cpu(gdp->bg_checksum));
3805                                         err = -EINVAL;
3806                                         goto restore_opts;
3807                                 }
3808                         }
3809
3810                         /*
3811                          * If we have an unprocessed orphan list hanging
3812                          * around from a previously readonly bdev mount,
3813                          * require a full umount/remount for now.
3814                          */
3815                         if (es->s_last_orphan) {
3816                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
3817                                        "remount RDWR because of unprocessed "
3818                                        "orphan inode list.  Please "
3819                                        "umount/remount instead");
3820                                 err = -EINVAL;
3821                                 goto restore_opts;
3822                         }
3823
3824                         /*
3825                          * Mounting a RDONLY partition read-write, so reread
3826                          * and store the current valid flag.  (It may have
3827                          * been changed by e2fsck since we originally mounted
3828                          * the partition.)
3829                          */
3830                         if (sbi->s_journal)
3831                                 ext4_clear_journal_err(sb, es);
3832                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3833                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3834                                 goto restore_opts;
3835                         if (!ext4_setup_super(sb, es, 0))
3836                                 sb->s_flags &= ~MS_RDONLY;
3837                         enable_quota = 1;
3838                 }
3839         }
3840         ext4_setup_system_zone(sb);
3841         if (sbi->s_journal == NULL)
3842                 ext4_commit_super(sb, 1);
3843
3844 #ifdef CONFIG_QUOTA
3845         /* Release old quota file names */
3846         for (i = 0; i < MAXQUOTAS; i++)
3847                 if (old_opts.s_qf_names[i] &&
3848                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3849                         kfree(old_opts.s_qf_names[i]);
3850 #endif
3851         unlock_super(sb);
3852         if (enable_quota)
3853                 dquot_resume(sb, -1);
3854
3855         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
3856         kfree(orig_data);
3857         return 0;
3858
3859 restore_opts:
3860         sb->s_flags = old_sb_flags;
3861         sbi->s_mount_opt = old_opts.s_mount_opt;
3862         sbi->s_resuid = old_opts.s_resuid;
3863         sbi->s_resgid = old_opts.s_resgid;
3864         sbi->s_commit_interval = old_opts.s_commit_interval;
3865         sbi->s_min_batch_time = old_opts.s_min_batch_time;
3866         sbi->s_max_batch_time = old_opts.s_max_batch_time;
3867 #ifdef CONFIG_QUOTA
3868         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3869         for (i = 0; i < MAXQUOTAS; i++) {
3870                 if (sbi->s_qf_names[i] &&
3871                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3872                         kfree(sbi->s_qf_names[i]);
3873                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3874         }
3875 #endif
3876         unlock_super(sb);
3877         kfree(orig_data);
3878         return err;
3879 }
3880
3881 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3882 {
3883         struct super_block *sb = dentry->d_sb;
3884         struct ext4_sb_info *sbi = EXT4_SB(sb);
3885         struct ext4_super_block *es = sbi->s_es;
3886         u64 fsid;
3887
3888         if (test_opt(sb, MINIX_DF)) {
3889                 sbi->s_overhead_last = 0;
3890         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3891                 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3892                 ext4_fsblk_t overhead = 0;
3893
3894                 /*
3895                  * Compute the overhead (FS structures).  This is constant
3896                  * for a given filesystem unless the number of block groups
3897                  * changes so we cache the previous value until it does.
3898                  */
3899
3900                 /*
3901                  * All of the blocks before first_data_block are
3902                  * overhead
3903                  */
3904                 overhead = le32_to_cpu(es->s_first_data_block);
3905
3906                 /*
3907                  * Add the overhead attributed to the superblock and
3908                  * block group descriptors.  If the sparse superblocks
3909                  * feature is turned on, then not all groups have this.
3910                  */
3911                 for (i = 0; i < ngroups; i++) {
3912                         overhead += ext4_bg_has_super(sb, i) +
3913                                 ext4_bg_num_gdb(sb, i);
3914                         cond_resched();
3915                 }
3916
3917                 /*
3918                  * Every block group has an inode bitmap, a block
3919                  * bitmap, and an inode table.
3920                  */
3921                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3922                 sbi->s_overhead_last = overhead;
3923                 smp_wmb();
3924                 sbi->s_blocks_last = ext4_blocks_count(es);
3925         }
3926
3927         buf->f_type = EXT4_SUPER_MAGIC;
3928         buf->f_bsize = sb->s_blocksize;
3929         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3930         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3931                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3932         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3933         if (buf->f_bfree < ext4_r_blocks_count(es))
3934                 buf->f_bavail = 0;
3935         buf->f_files = le32_to_cpu(es->s_inodes_count);
3936         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3937         buf->f_namelen = EXT4_NAME_LEN;
3938         fsid = le64_to_cpup((void *)es->s_uuid) ^
3939                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3940         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3941         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3942
3943         return 0;
3944 }
3945
3946 /* Helper function for writing quotas on sync - we need to start transaction
3947  * before quota file is locked for write. Otherwise the are possible deadlocks:
3948  * Process 1                         Process 2
3949  * ext4_create()                     quota_sync()
3950  *   jbd2_journal_start()                  write_dquot()
3951  *   dquot_initialize()                         down(dqio_mutex)
3952  *     down(dqio_mutex)                    jbd2_journal_start()
3953  *
3954  */
3955
3956 #ifdef CONFIG_QUOTA
3957
3958 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3959 {
3960         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3961 }
3962
3963 static int ext4_write_dquot(struct dquot *dquot)
3964 {
3965         int ret, err;
3966         handle_t *handle;
3967         struct inode *inode;
3968
3969         inode = dquot_to_inode(dquot);
3970         handle = ext4_journal_start(inode,
3971                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3972         if (IS_ERR(handle))
3973                 return PTR_ERR(handle);
3974         ret = dquot_commit(dquot);
3975         err = ext4_journal_stop(handle);
3976         if (!ret)
3977                 ret = err;
3978         return ret;
3979 }
3980
3981 static int ext4_acquire_dquot(struct dquot *dquot)
3982 {
3983         int ret, err;
3984         handle_t *handle;
3985
3986         handle = ext4_journal_start(dquot_to_inode(dquot),
3987                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3988         if (IS_ERR(handle))
3989                 return PTR_ERR(handle);
3990         ret = dquot_acquire(dquot);
3991         err = ext4_journal_stop(handle);
3992         if (!ret)
3993                 ret = err;
3994         return ret;
3995 }
3996
3997 static int ext4_release_dquot(struct dquot *dquot)
3998 {
3999         int ret, err;
4000         handle_t *handle;
4001
4002         handle = ext4_journal_start(dquot_to_inode(dquot),
4003                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4004         if (IS_ERR(handle)) {
4005                 /* Release dquot anyway to avoid endless cycle in dqput() */
4006                 dquot_release(dquot);
4007                 return PTR_ERR(handle);
4008         }
4009         ret = dquot_release(dquot);
4010         err = ext4_journal_stop(handle);
4011         if (!ret)
4012                 ret = err;
4013         return ret;
4014 }
4015
4016 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4017 {
4018         /* Are we journaling quotas? */
4019         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4020             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4021                 dquot_mark_dquot_dirty(dquot);
4022                 return ext4_write_dquot(dquot);
4023         } else {
4024                 return dquot_mark_dquot_dirty(dquot);
4025         }
4026 }
4027
4028 static int ext4_write_info(struct super_block *sb, int type)
4029 {
4030         int ret, err;
4031         handle_t *handle;
4032
4033         /* Data block + inode block */
4034         handle = ext4_journal_start(sb->s_root->d_inode, 2);
4035         if (IS_ERR(handle))
4036                 return PTR_ERR(handle);
4037         ret = dquot_commit_info(sb, type);
4038         err = ext4_journal_stop(handle);
4039         if (!ret)
4040                 ret = err;
4041         return ret;
4042 }
4043
4044 /*
4045  * Turn on quotas during mount time - we need to find
4046  * the quota file and such...
4047  */
4048 static int ext4_quota_on_mount(struct super_block *sb, int type)
4049 {
4050         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4051                                         EXT4_SB(sb)->s_jquota_fmt, type);
4052 }
4053
4054 /*
4055  * Standard function to be called on quota_on
4056  */
4057 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4058                          char *name)
4059 {
4060         int err;
4061         struct path path;
4062
4063         if (!test_opt(sb, QUOTA))
4064                 return -EINVAL;
4065
4066         err = kern_path(name, LOOKUP_FOLLOW, &path);
4067         if (err)
4068                 return err;
4069
4070         /* Quotafile not on the same filesystem? */
4071         if (path.mnt->mnt_sb != sb) {
4072                 path_put(&path);
4073                 return -EXDEV;
4074         }
4075         /* Journaling quota? */
4076         if (EXT4_SB(sb)->s_qf_names[type]) {
4077                 /* Quotafile not in fs root? */
4078                 if (path.dentry->d_parent != sb->s_root)
4079                         ext4_msg(sb, KERN_WARNING,
4080                                 "Quota file not on filesystem root. "
4081                                 "Journaled quota will not work");
4082         }
4083
4084         /*
4085          * When we journal data on quota file, we have to flush journal to see
4086          * all updates to the file when we bypass pagecache...
4087          */
4088         if (EXT4_SB(sb)->s_journal &&
4089             ext4_should_journal_data(path.dentry->d_inode)) {
4090                 /*
4091                  * We don't need to lock updates but journal_flush() could
4092                  * otherwise be livelocked...
4093                  */
4094                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4095                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4096                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4097                 if (err) {
4098                         path_put(&path);
4099                         return err;
4100                 }
4101         }
4102
4103         err = dquot_quota_on_path(sb, type, format_id, &path);
4104         path_put(&path);
4105         return err;
4106 }
4107
4108 static int ext4_quota_off(struct super_block *sb, int type)
4109 {
4110         /* Force all delayed allocation blocks to be allocated */
4111         if (test_opt(sb, DELALLOC)) {
4112                 down_read(&sb->s_umount);
4113                 sync_filesystem(sb);
4114                 up_read(&sb->s_umount);
4115         }
4116
4117         return dquot_quota_off(sb, type);
4118 }
4119
4120 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4121  * acquiring the locks... As quota files are never truncated and quota code
4122  * itself serializes the operations (and noone else should touch the files)
4123  * we don't have to be afraid of races */
4124 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4125                                size_t len, loff_t off)
4126 {
4127         struct inode *inode = sb_dqopt(sb)->files[type];
4128         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4129         int err = 0;
4130         int offset = off & (sb->s_blocksize - 1);
4131         int tocopy;
4132         size_t toread;
4133         struct buffer_head *bh;
4134         loff_t i_size = i_size_read(inode);
4135
4136         if (off > i_size)
4137                 return 0;
4138         if (off+len > i_size)
4139                 len = i_size-off;
4140         toread = len;
4141         while (toread > 0) {
4142                 tocopy = sb->s_blocksize - offset < toread ?
4143                                 sb->s_blocksize - offset : toread;
4144                 bh = ext4_bread(NULL, inode, blk, 0, &err);
4145                 if (err)
4146                         return err;
4147                 if (!bh)        /* A hole? */
4148                         memset(data, 0, tocopy);
4149                 else
4150                         memcpy(data, bh->b_data+offset, tocopy);
4151                 brelse(bh);
4152                 offset = 0;
4153                 toread -= tocopy;
4154                 data += tocopy;
4155                 blk++;
4156         }
4157         return len;
4158 }
4159
4160 /* Write to quotafile (we know the transaction is already started and has
4161  * enough credits) */
4162 static ssize_t ext4_quota_write(struct super_block *sb, int type,
4163                                 const char *data, size_t len, loff_t off)
4164 {
4165         struct inode *inode = sb_dqopt(sb)->files[type];
4166         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4167         int err = 0;
4168         int offset = off & (sb->s_blocksize - 1);
4169         struct buffer_head *bh;
4170         handle_t *handle = journal_current_handle();
4171
4172         if (EXT4_SB(sb)->s_journal && !handle) {
4173                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4174                         " cancelled because transaction is not started",
4175                         (unsigned long long)off, (unsigned long long)len);
4176                 return -EIO;
4177         }
4178         /*
4179          * Since we account only one data block in transaction credits,
4180          * then it is impossible to cross a block boundary.
4181          */
4182         if (sb->s_blocksize - offset < len) {
4183                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4184                         " cancelled because not block aligned",
4185                         (unsigned long long)off, (unsigned long long)len);
4186                 return -EIO;
4187         }
4188
4189         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
4190         bh = ext4_bread(handle, inode, blk, 1, &err);
4191         if (!bh)
4192                 goto out;
4193         err = ext4_journal_get_write_access(handle, bh);
4194         if (err) {
4195                 brelse(bh);
4196                 goto out;
4197         }
4198         lock_buffer(bh);
4199         memcpy(bh->b_data+offset, data, len);
4200         flush_dcache_page(bh->b_page);
4201         unlock_buffer(bh);
4202         err = ext4_handle_dirty_metadata(handle, NULL, bh);
4203         brelse(bh);
4204 out:
4205         if (err) {
4206                 mutex_unlock(&inode->i_mutex);
4207                 return err;
4208         }
4209         if (inode->i_size < off + len) {
4210                 i_size_write(inode, off + len);
4211                 EXT4_I(inode)->i_disksize = inode->i_size;
4212         }
4213         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4214         ext4_mark_inode_dirty(handle, inode);
4215         mutex_unlock(&inode->i_mutex);
4216         return len;
4217 }
4218
4219 #endif
4220
4221 static int ext4_get_sb(struct file_system_type *fs_type, int flags,
4222                        const char *dev_name, void *data, struct vfsmount *mnt)
4223 {
4224         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super,mnt);
4225 }
4226
4227 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4228 static struct file_system_type ext2_fs_type = {
4229         .owner          = THIS_MODULE,
4230         .name           = "ext2",
4231         .get_sb         = ext4_get_sb,
4232         .kill_sb        = kill_block_super,
4233         .fs_flags       = FS_REQUIRES_DEV,
4234 };
4235
4236 static inline void register_as_ext2(void)
4237 {
4238         int err = register_filesystem(&ext2_fs_type);
4239         if (err)
4240                 printk(KERN_WARNING
4241                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4242 }
4243
4244 static inline void unregister_as_ext2(void)
4245 {
4246         unregister_filesystem(&ext2_fs_type);
4247 }
4248 MODULE_ALIAS("ext2");
4249 #else
4250 static inline void register_as_ext2(void) { }
4251 static inline void unregister_as_ext2(void) { }
4252 #endif
4253
4254 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4255 static inline void register_as_ext3(void)
4256 {
4257         int err = register_filesystem(&ext3_fs_type);
4258         if (err)
4259                 printk(KERN_WARNING
4260                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4261 }
4262
4263 static inline void unregister_as_ext3(void)
4264 {
4265         unregister_filesystem(&ext3_fs_type);
4266 }
4267 MODULE_ALIAS("ext3");
4268 #else
4269 static inline void register_as_ext3(void) { }
4270 static inline void unregister_as_ext3(void) { }
4271 #endif
4272
4273 static struct file_system_type ext4_fs_type = {
4274         .owner          = THIS_MODULE,
4275         .name           = "ext4",
4276         .get_sb         = ext4_get_sb,
4277         .kill_sb        = kill_block_super,
4278         .fs_flags       = FS_REQUIRES_DEV,
4279 };
4280
4281 static int __init init_ext4_fs(void)
4282 {
4283         int err;
4284
4285         ext4_check_flag_values();
4286         err = init_ext4_system_zone();
4287         if (err)
4288                 return err;
4289         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
4290         if (!ext4_kset)
4291                 goto out4;
4292         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
4293         err = init_ext4_mballoc();
4294         if (err)
4295                 goto out3;
4296
4297         err = init_ext4_xattr();
4298         if (err)
4299                 goto out2;
4300         err = init_inodecache();
4301         if (err)
4302                 goto out1;
4303         register_as_ext2();
4304         register_as_ext3();
4305         err = register_filesystem(&ext4_fs_type);
4306         if (err)
4307                 goto out;
4308         return 0;
4309 out:
4310         unregister_as_ext2();
4311         unregister_as_ext3();
4312         destroy_inodecache();
4313 out1:
4314         exit_ext4_xattr();
4315 out2:
4316         exit_ext4_mballoc();
4317 out3:
4318         remove_proc_entry("fs/ext4", NULL);
4319         kset_unregister(ext4_kset);
4320 out4:
4321         exit_ext4_system_zone();
4322         return err;
4323 }
4324
4325 static void __exit exit_ext4_fs(void)
4326 {
4327         unregister_as_ext2();
4328         unregister_as_ext3();
4329         unregister_filesystem(&ext4_fs_type);
4330         destroy_inodecache();
4331         exit_ext4_xattr();
4332         exit_ext4_mballoc();
4333         remove_proc_entry("fs/ext4", NULL);
4334         kset_unregister(ext4_kset);
4335         exit_ext4_system_zone();
4336 }
4337
4338 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4339 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4340 MODULE_LICENSE("GPL");
4341 module_init(init_ext4_fs)
4342 module_exit(exit_ext4_fs)