fs/ext4/file.c

   1 /*
   2  *  linux/fs/ext4/file.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/file.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  ext4 fs regular file handling primitives
  16  *
  17  *  64-bit file support on 64-bit platforms by Jakub Jelinek
  18  *      (jj@sunsite.ms.mff.cuni.cz)
  19  */
  20
  21 #include <linux/time.h>
  22 #include <linux/fs.h>
  23 #include <linux/mount.h>
  24 #include <linux/path.h>
  25 #include <linux/aio.h>
  26 #include <linux/quotaops.h>
  27 #include <linux/pagevec.h>
  28 #include "ext4.h"
  29 #include "ext4_jbd2.h"
  30 #include "xattr.h"
  31 #include "acl.h"
  32
  33 /*
  34  * Called when an inode is released. Note that this is different
  35  * from ext4_file_open: open gets called at every open, but release
  36  * gets called only when /all/ the files are closed.
  37  */
  38 static int ext4_release_file(struct inode *inode, struct file *filp)
  39 {
  40         if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
  41                 ext4_alloc_da_blocks(inode);
  42                 ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
  43         }
  44         /* if we are the last writer on the inode, drop the block reservation */
  45         if ((filp->f_mode & FMODE_WRITE) &&
  46                         (atomic_read(&inode->i_writecount) == 1) &&
  47                         !EXT4_I(inode)->i_reserved_data_blocks)
  48         {
  49                 down_write(&EXT4_I(inode)->i_data_sem);
  50                 ext4_discard_preallocations(inode);
  51                 up_write(&EXT4_I(inode)->i_data_sem);
  52         }
  53         if (is_dx(inode) && filp->private_data)
  54                 ext4_htree_free_dir_info(filp->private_data);
  55
  56         return 0;
  57 }
  58
  59 static void ext4_unwritten_wait(struct inode *inode)
  60 {
  61         wait_queue_head_t *wq = ext4_ioend_wq(inode);
  62
  63         wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0));
  64 }
  65
  66 /*
  67  * This tests whether the IO in question is block-aligned or not.
  68  * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
  69  * are converted to written only after the IO is complete.  Until they are
  70  * mapped, these blocks appear as holes, so dio_zero_block() will assume that
  71  * it needs to zero out portions of the start and/or end block.  If 2 AIO
  72  * threads are at work on the same unwritten block, they must be synchronized
  73  * or one thread will zero the other's data, causing corruption.
  74  */
  75 static int
  76 ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos)
  77 {
  78         struct super_block *sb = inode->i_sb;
  79         int blockmask = sb->s_blocksize - 1;
  80
  81         if (pos >= i_size_read(inode))
  82                 return 0;
  83
  84         if ((pos | iov_iter_alignment(from)) & blockmask)
  85                 return 1;
  86
  87         return 0;
  88 }
  89
  90 static ssize_t
  91 ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
  92 {
  93         struct file *file = iocb->ki_filp;
  94         struct inode *inode = file_inode(iocb->ki_filp);
  95         struct mutex *aio_mutex = NULL;
  96         struct blk_plug plug;
  97         int o_direct = io_is_direct(file);
  98         int overwrite = 0;
  99         size_t length = iov_iter_count(from);
 100         ssize_t ret;
 101         loff_t pos = iocb->ki_pos;
 102
 103         /*
 104          * Unaligned direct AIO must be serialized; see comment above
 105          * In the case of O_APPEND, assume that we must always serialize
 106          */
 107         if (o_direct &&
 108             ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
 109             !is_sync_kiocb(iocb) &&
 110             (file->f_flags & O_APPEND ||
 111              ext4_unaligned_aio(inode, from, pos))) {
 112                 aio_mutex = ext4_aio_mutex(inode);
 113                 mutex_lock(aio_mutex);
 114                 ext4_unwritten_wait(inode);
 115         }
 116
 117         mutex_lock(&inode->i_mutex);
 118         if (file->f_flags & O_APPEND)
 119                 iocb->ki_pos = pos = i_size_read(inode);
 120
 121         /*
 122          * If we have encountered a bitmap-format file, the size limit
 123          * is smaller than s_maxbytes, which is for extent-mapped files.
 124          */
 125         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
 126                 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 127
 128                 if ((pos > sbi->s_bitmap_maxbytes) ||
 129                     (pos == sbi->s_bitmap_maxbytes && length > 0)) {
 130                         mutex_unlock(&inode->i_mutex);
 131                         ret = -EFBIG;
 132                         goto errout;
 133                 }
 134
 135                 if (pos + length > sbi->s_bitmap_maxbytes)
 136                         iov_iter_truncate(from, sbi->s_bitmap_maxbytes - pos);
 137         }
 138
 139         iocb->private = &overwrite;
 140         if (o_direct) {
 141                 blk_start_plug(&plug);
 142
 143
 144                 /* check whether we do a DIO overwrite or not */
 145                 if (ext4_should_dioread_nolock(inode) && !aio_mutex &&
 146                     !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) {
 147                         struct ext4_map_blocks map;
 148                         unsigned int blkbits = inode->i_blkbits;
 149                         int err, len;
 150
 151                         map.m_lblk = pos >> blkbits;
 152                         map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits)
 153                                 - map.m_lblk;
 154                         len = map.m_len;
 155
 156                         err = ext4_map_blocks(NULL, inode, &map, 0);
 157                         /*
 158                          * 'err==len' means that all of blocks has
 159                          * been preallocated no matter they are
 160                          * initialized or not.  For excluding
 161                          * unwritten extents, we need to check
 162                          * m_flags.  There are two conditions that
 163                          * indicate for initialized extents.  1) If we
 164                          * hit extent cache, EXT4_MAP_MAPPED flag is
 165                          * returned; 2) If we do a real lookup,
 166                          * non-flags are returned.  So we should check
 167                          * these two conditions.
 168                          */
 169                         if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
 170                                 overwrite = 1;
 171                 }
 172         }
 173
 174         ret = __generic_file_write_iter(iocb, from);
 175         mutex_unlock(&inode->i_mutex);
 176
 177         if (ret > 0) {
 178                 ssize_t err;
 179
 180                 err = generic_write_sync(file, iocb->ki_pos - ret, ret);
 181                 if (err < 0)
 182                         ret = err;
 183         }
 184         if (o_direct)
 185                 blk_finish_plug(&plug);
 186
 187 errout:
 188         if (aio_mutex)
 189                 mutex_unlock(aio_mutex);
 190         return ret;
 191 }
 192
 193 #ifdef CONFIG_FS_DAX
 194 static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 195 {
 196         return dax_fault(vma, vmf, ext4_get_block);
 197                                         /* Is this the right get_block? */
 198 }
 199
 200 static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 201 {
 202         return dax_mkwrite(vma, vmf, ext4_get_block);
 203 }
 204
 205 static const struct vm_operations_struct ext4_dax_vm_ops = {
 206         .fault          = ext4_dax_fault,
 207         .page_mkwrite   = ext4_dax_mkwrite,
 208 };
 209 #else
 210 #define ext4_dax_vm_ops ext4_file_vm_ops
 211 #endif
 212
 213 static const struct vm_operations_struct ext4_file_vm_ops = {
 214         .fault          = filemap_fault,
 215         .map_pages      = filemap_map_pages,
 216         .page_mkwrite   = ext4_page_mkwrite,
 217 };
 218
 219 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 220 {
 221         struct inode *inode = file->f_mapping->host;
 222
 223         if (ext4_encrypted_inode(inode)) {
 224                 int err = ext4_generate_encryption_key(inode);
 225                 if (err)
 226                         return 0;
 227         }
 228         file_accessed(file);
 229         if (IS_DAX(file_inode(file))) {
 230                 vma->vm_ops = &ext4_dax_vm_ops;
 231                 vma->vm_flags |= VM_MIXEDMAP;
 232         } else {
 233                 vma->vm_ops = &ext4_file_vm_ops;
 234         }
 235         return 0;
 236 }
 237
 238 static int ext4_file_open(struct inode * inode, struct file * filp)
 239 {
 240         struct super_block *sb = inode->i_sb;
 241         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 242         struct vfsmount *mnt = filp->f_path.mnt;
 243         struct path path;
 244         char buf[64], *cp;
 245         int ret;
 246
 247         if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
 248                      !(sb->s_flags & MS_RDONLY))) {
 249                 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
 250                 /*
 251                  * Sample where the filesystem has been mounted and
 252                  * store it in the superblock for sysadmin convenience
 253                  * when trying to sort through large numbers of block
 254                  * devices or filesystem images.
 255                  */
 256                 memset(buf, 0, sizeof(buf));
 257                 path.mnt = mnt;
 258                 path.dentry = mnt->mnt_root;
 259                 cp = d_path(&path, buf, sizeof(buf));
 260                 if (!IS_ERR(cp)) {
 261                         handle_t *handle;
 262                         int err;
 263
 264                         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
 265                         if (IS_ERR(handle))
 266                                 return PTR_ERR(handle);
 267                         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 268                         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
 269                         if (err) {
 270                                 ext4_journal_stop(handle);
 271                                 return err;
 272                         }
 273                         strlcpy(sbi->s_es->s_last_mounted, cp,
 274                                 sizeof(sbi->s_es->s_last_mounted));
 275                         ext4_handle_dirty_super(handle, sb);
 276                         ext4_journal_stop(handle);
 277                 }
 278         }
 279         /*
 280          * Set up the jbd2_inode if we are opening the inode for
 281          * writing and the journal is present
 282          */
 283         if (filp->f_mode & FMODE_WRITE) {
 284                 ret = ext4_inode_attach_jinode(inode);
 285                 if (ret < 0)
 286                         return ret;
 287         }
 288         ret = dquot_file_open(inode, filp);
 289         if (!ret && ext4_encrypted_inode(inode)) {
 290                 ret = ext4_generate_encryption_key(inode);
 291                 if (ret)
 292                         ret = -EACCES;
 293         }
 294         return ret;
 295 }
 296
 297 /*
 298  * Here we use ext4_map_blocks() to get a block mapping for a extent-based
 299  * file rather than ext4_ext_walk_space() because we can introduce
 300  * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same
 301  * function.  When extent status tree has been fully implemented, it will
 302  * track all extent status for a file and we can directly use it to
 303  * retrieve the offset for SEEK_DATA/SEEK_HOLE.
 304  */
 305
 306 /*
 307  * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to
 308  * lookup page cache to check whether or not there has some data between
 309  * [startoff, endoff] because, if this range contains an unwritten extent,
 310  * we determine this extent as a data or a hole according to whether the
 311  * page cache has data or not.
 312  */
 313 static int ext4_find_unwritten_pgoff(struct inode *inode,
 314                                      int whence,
 315                                      struct ext4_map_blocks *map,
 316                                      loff_t *offset)
 317 {
 318         struct pagevec pvec;
 319         unsigned int blkbits;
 320         pgoff_t index;
 321         pgoff_t end;
 322         loff_t endoff;
 323         loff_t startoff;
 324         loff_t lastoff;
 325         int found = 0;
 326
 327         blkbits = inode->i_sb->s_blocksize_bits;
 328         startoff = *offset;
 329         lastoff = startoff;
 330         endoff = (loff_t)(map->m_lblk + map->m_len) << blkbits;
 331
 332         index = startoff >> PAGE_CACHE_SHIFT;
 333         end = endoff >> PAGE_CACHE_SHIFT;
 334
 335         pagevec_init(&pvec, 0);
 336         do {
 337                 int i, num;
 338                 unsigned long nr_pages;
 339
 340                 num = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
 341                 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
 342                                           (pgoff_t)num);
 343                 if (nr_pages == 0) {
 344                         if (whence == SEEK_DATA)
 345                                 break;
 346
 347                         BUG_ON(whence != SEEK_HOLE);
 348                         /*
 349                          * If this is the first time to go into the loop and
 350                          * offset is not beyond the end offset, it will be a
 351                          * hole at this offset
 352                          */
 353                         if (lastoff == startoff || lastoff < endoff)
 354                                 found = 1;
 355                         break;
 356                 }
 357
 358                 /*
 359                  * If this is the first time to go into the loop and
 360                  * offset is smaller than the first page offset, it will be a
 361                  * hole at this offset.
 362                  */
 363                 if (lastoff == startoff && whence == SEEK_HOLE &&
 364                     lastoff < page_offset(pvec.pages[0])) {
 365                         found = 1;
 366                         break;
 367                 }
 368
 369                 for (i = 0; i < nr_pages; i++) {
 370                         struct page *page = pvec.pages[i];
 371                         struct buffer_head *bh, *head;
 372
 373                         /*
 374                          * If the current offset is not beyond the end of given
 375                          * range, it will be a hole.
 376                          */
 377                         if (lastoff < endoff && whence == SEEK_HOLE &&
 378                             page->index > end) {
 379                                 found = 1;
 380                                 *offset = lastoff;
 381                                 goto out;
 382                         }
 383
 384                         lock_page(page);
 385
 386                         if (unlikely(page->mapping != inode->i_mapping)) {
 387                                 unlock_page(page);
 388                                 continue;
 389                         }
 390
 391                         if (!page_has_buffers(page)) {
 392                                 unlock_page(page);
 393                                 continue;
 394                         }
 395
 396                         if (page_has_buffers(page)) {
 397                                 lastoff = page_offset(page);
 398                                 bh = head = page_buffers(page);
 399                                 do {
 400                                         if (buffer_uptodate(bh) ||
 401                                             buffer_unwritten(bh)) {
 402                                                 if (whence == SEEK_DATA)
 403                                                         found = 1;
 404                                         } else {
 405                                                 if (whence == SEEK_HOLE)
 406                                                         found = 1;
 407                                         }
 408                                         if (found) {
 409                                                 *offset = max_t(loff_t,
 410                                                         startoff, lastoff);
 411                                                 unlock_page(page);
 412                                                 goto out;
 413                                         }
 414                                         lastoff += bh->b_size;
 415                                         bh = bh->b_this_page;
 416                                 } while (bh != head);
 417                         }
 418
 419                         lastoff = page_offset(page) + PAGE_SIZE;
 420                         unlock_page(page);
 421                 }
 422
 423                 /*
 424                  * The no. of pages is less than our desired, that would be a
 425                  * hole in there.
 426                  */
 427                 if (nr_pages < num && whence == SEEK_HOLE) {
 428                         found = 1;
 429                         *offset = lastoff;
 430                         break;
 431                 }
 432
 433                 index = pvec.pages[i - 1]->index + 1;
 434                 pagevec_release(&pvec);
 435         } while (index <= end);
 436
 437 out:
 438         pagevec_release(&pvec);
 439         return found;
 440 }
 441
 442 /*
 443  * ext4_seek_data() retrieves the offset for SEEK_DATA.
 444  */
 445 static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
 446 {
 447         struct inode *inode = file->f_mapping->host;
 448         struct ext4_map_blocks map;
 449         struct extent_status es;
 450         ext4_lblk_t start, last, end;
 451         loff_t dataoff, isize;
 452         int blkbits;
 453         int ret = 0;
 454
 455         mutex_lock(&inode->i_mutex);
 456
 457         isize = i_size_read(inode);
 458         if (offset >= isize) {
 459                 mutex_unlock(&inode->i_mutex);
 460                 return -ENXIO;
 461         }
 462
 463         blkbits = inode->i_sb->s_blocksize_bits;
 464         start = offset >> blkbits;
 465         last = start;
 466         end = isize >> blkbits;
 467         dataoff = offset;
 468
 469         do {
 470                 map.m_lblk = last;
 471                 map.m_len = end - last + 1;
 472                 ret = ext4_map_blocks(NULL, inode, &map, 0);
 473                 if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {
 474                         if (last != start)
 475                                 dataoff = (loff_t)last << blkbits;
 476                         break;
 477                 }
 478
 479                 /*
 480                  * If there is a delay extent at this offset,
 481                  * it will be as a data.
 482                  */
 483                 ext4_es_find_delayed_extent_range(inode, last, last, &es);
 484                 if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
 485                         if (last != start)
 486                                 dataoff = (loff_t)last << blkbits;
 487                         break;
 488                 }
 489
 490                 /*
 491                  * If there is a unwritten extent at this offset,
 492                  * it will be as a data or a hole according to page
 493                  * cache that has data or not.
 494                  */
 495                 if (map.m_flags & EXT4_MAP_UNWRITTEN) {
 496                         int unwritten;
 497                         unwritten = ext4_find_unwritten_pgoff(inode, SEEK_DATA,
 498                                                               &map, &dataoff);
 499                         if (unwritten)
 500                                 break;
 501                 }
 502
 503                 last++;
 504                 dataoff = (loff_t)last << blkbits;
 505         } while (last <= end);
 506
 507         mutex_unlock(&inode->i_mutex);
 508
 509         if (dataoff > isize)
 510                 return -ENXIO;
 511
 512         return vfs_setpos(file, dataoff, maxsize);
 513 }
 514
 515 /*
 516  * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
 517  */
 518 static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
 519 {
 520         struct inode *inode = file->f_mapping->host;
 521         struct ext4_map_blocks map;
 522         struct extent_status es;
 523         ext4_lblk_t start, last, end;
 524         loff_t holeoff, isize;
 525         int blkbits;
 526         int ret = 0;
 527
 528         mutex_lock(&inode->i_mutex);
 529
 530         isize = i_size_read(inode);
 531         if (offset >= isize) {
 532                 mutex_unlock(&inode->i_mutex);
 533                 return -ENXIO;
 534         }
 535
 536         blkbits = inode->i_sb->s_blocksize_bits;
 537         start = offset >> blkbits;
 538         last = start;
 539         end = isize >> blkbits;
 540         holeoff = offset;
 541
 542         do {
 543                 map.m_lblk = last;
 544                 map.m_len = end - last + 1;
 545                 ret = ext4_map_blocks(NULL, inode, &map, 0);
 546                 if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {
 547                         last += ret;
 548                         holeoff = (loff_t)last << blkbits;
 549                         continue;
 550                 }
 551
 552                 /*
 553                  * If there is a delay extent at this offset,
 554                  * we will skip this extent.
 555                  */
 556                 ext4_es_find_delayed_extent_range(inode, last, last, &es);
 557                 if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
 558                         last = es.es_lblk + es.es_len;
 559                         holeoff = (loff_t)last << blkbits;
 560                         continue;
 561                 }
 562
 563                 /*
 564                  * If there is a unwritten extent at this offset,
 565                  * it will be as a data or a hole according to page
 566                  * cache that has data or not.
 567                  */
 568                 if (map.m_flags & EXT4_MAP_UNWRITTEN) {
 569                         int unwritten;
 570                         unwritten = ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
 571                                                               &map, &holeoff);
 572                         if (!unwritten) {
 573                                 last += ret;
 574                                 holeoff = (loff_t)last << blkbits;
 575                                 continue;
 576                         }
 577                 }
 578
 579                 /* find a hole */
 580                 break;
 581         } while (last <= end);
 582
 583         mutex_unlock(&inode->i_mutex);
 584
 585         if (holeoff > isize)
 586                 holeoff = isize;
 587
 588         return vfs_setpos(file, holeoff, maxsize);
 589 }
 590
 591 /*
 592  * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
 593  * by calling generic_file_llseek_size() with the appropriate maxbytes
 594  * value for each.
 595  */
 596 loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
 597 {
 598         struct inode *inode = file->f_mapping->host;
 599         loff_t maxbytes;
 600
 601         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
 602                 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
 603         else
 604                 maxbytes = inode->i_sb->s_maxbytes;
 605
 606         switch (whence) {
 607         case SEEK_SET:
 608         case SEEK_CUR:
 609         case SEEK_END:
 610                 return generic_file_llseek_size(file, offset, whence,
 611                                                 maxbytes, i_size_read(inode));
 612         case SEEK_DATA:
 613                 return ext4_seek_data(file, offset, maxbytes);
 614         case SEEK_HOLE:
 615                 return ext4_seek_hole(file, offset, maxbytes);
 616         }
 617
 618         return -EINVAL;
 619 }
 620
 621 const struct file_operations ext4_file_operations = {
 622         .llseek         = ext4_llseek,
 623         .read           = new_sync_read,
 624         .write          = new_sync_write,
 625         .read_iter      = generic_file_read_iter,
 626         .write_iter     = ext4_file_write_iter,
 627         .unlocked_ioctl = ext4_ioctl,
 628 #ifdef CONFIG_COMPAT
 629         .compat_ioctl   = ext4_compat_ioctl,
 630 #endif
 631         .mmap           = ext4_file_mmap,
 632         .open           = ext4_file_open,
 633         .release        = ext4_release_file,
 634         .fsync          = ext4_sync_file,
 635         .splice_read    = generic_file_splice_read,
 636         .splice_write   = iter_file_splice_write,
 637         .fallocate      = ext4_fallocate,
 638 };
 639
 640 #ifdef CONFIG_FS_DAX
 641 const struct file_operations ext4_dax_file_operations = {
 642         .llseek         = ext4_llseek,
 643         .read           = new_sync_read,
 644         .write          = new_sync_write,
 645         .read_iter      = generic_file_read_iter,
 646         .write_iter     = ext4_file_write_iter,
 647         .unlocked_ioctl = ext4_ioctl,
 648 #ifdef CONFIG_COMPAT
 649         .compat_ioctl   = ext4_compat_ioctl,
 650 #endif
 651         .mmap           = ext4_file_mmap,
 652         .open           = ext4_file_open,
 653         .release        = ext4_release_file,
 654         .fsync          = ext4_sync_file,
 655         /* Splice not yet supported with DAX */
 656         .fallocate      = ext4_fallocate,
 657 };
 658 #endif
 659
 660 const struct inode_operations ext4_file_inode_operations = {
 661         .setattr        = ext4_setattr,
 662         .getattr        = ext4_getattr,
 663         .setxattr       = generic_setxattr,
 664         .getxattr       = generic_getxattr,
 665         .listxattr      = ext4_listxattr,
 666         .removexattr    = generic_removexattr,
 667         .get_acl        = ext4_get_acl,
 668         .set_acl        = ext4_set_acl,
 669         .fiemap         = ext4_fiemap,
 670 };
 671