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/dax.h>
  26 #include <linux/quotaops.h>
  27 #include <linux/pagevec.h>
  28 #include <linux/uio.h>
  29 #include "ext4.h"
  30 #include "ext4_jbd2.h"
  31 #include "xattr.h"
  32 #include "acl.h"
  33
  34 /*
  35  * Called when an inode is released. Note that this is different
  36  * from ext4_file_open: open gets called at every open, but release
  37  * gets called only when /all/ the files are closed.
  38  */
  39 static int ext4_release_file(struct inode *inode, struct file *filp)
  40 {
  41         if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
  42                 ext4_alloc_da_blocks(inode);
  43                 ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
  44         }
  45         /* if we are the last writer on the inode, drop the block reservation */
  46         if ((filp->f_mode & FMODE_WRITE) &&
  47                         (atomic_read(&inode->i_writecount) == 1) &&
  48                         !EXT4_I(inode)->i_reserved_data_blocks)
  49         {
  50                 down_write(&EXT4_I(inode)->i_data_sem);
  51                 ext4_discard_preallocations(inode);
  52                 up_write(&EXT4_I(inode)->i_data_sem);
  53         }
  54         if (is_dx(inode) && filp->private_data)
  55                 ext4_htree_free_dir_info(filp->private_data);
  56
  57         return 0;
  58 }
  59
  60 static void ext4_unwritten_wait(struct inode *inode)
  61 {
  62         wait_queue_head_t *wq = ext4_ioend_wq(inode);
  63
  64         wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0));
  65 }
  66
  67 /*
  68  * This tests whether the IO in question is block-aligned or not.
  69  * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
  70  * are converted to written only after the IO is complete.  Until they are
  71  * mapped, these blocks appear as holes, so dio_zero_block() will assume that
  72  * it needs to zero out portions of the start and/or end block.  If 2 AIO
  73  * threads are at work on the same unwritten block, they must be synchronized
  74  * or one thread will zero the other's data, causing corruption.
  75  */
  76 static int
  77 ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos)
  78 {
  79         struct super_block *sb = inode->i_sb;
  80         int blockmask = sb->s_blocksize - 1;
  81
  82         if (pos >= i_size_read(inode))
  83                 return 0;
  84
  85         if ((pos | iov_iter_alignment(from)) & blockmask)
  86                 return 1;
  87
  88         return 0;
  89 }
  90
  91 static ssize_t
  92 ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
  93 {
  94         struct file *file = iocb->ki_filp;
  95         struct inode *inode = file_inode(iocb->ki_filp);
  96         struct mutex *aio_mutex = NULL;
  97         struct blk_plug plug;
  98         int o_direct = iocb->ki_flags & IOCB_DIRECT;
  99         int overwrite = 0;
 100         ssize_t ret;
 101
 102         /*
 103          * Unaligned direct AIO must be serialized; see comment above
 104          * In the case of O_APPEND, assume that we must always serialize
 105          */
 106         if (o_direct &&
 107             ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
 108             !is_sync_kiocb(iocb) &&
 109             (iocb->ki_flags & IOCB_APPEND ||
 110              ext4_unaligned_aio(inode, from, iocb->ki_pos))) {
 111                 aio_mutex = ext4_aio_mutex(inode);
 112                 mutex_lock(aio_mutex);
 113                 ext4_unwritten_wait(inode);
 114         }
 115
 116         mutex_lock(&inode->i_mutex);
 117         ret = generic_write_checks(iocb, from);
 118         if (ret <= 0)
 119                 goto out;
 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 (iocb->ki_pos >= sbi->s_bitmap_maxbytes) {
 129                         ret = -EFBIG;
 130                         goto out;
 131                 }
 132                 iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
 133         }
 134
 135         iocb->private = &overwrite;
 136         if (o_direct) {
 137                 size_t length = iov_iter_count(from);
 138                 loff_t pos = iocb->ki_pos;
 139                 blk_start_plug(&plug);
 140
 141                 /* check whether we do a DIO overwrite or not */
 142                 if (ext4_should_dioread_nolock(inode) && !aio_mutex &&
 143                     !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) {
 144                         struct ext4_map_blocks map;
 145                         unsigned int blkbits = inode->i_blkbits;
 146                         int err, len;
 147
 148                         map.m_lblk = pos >> blkbits;
 149                         map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits)
 150                                 - map.m_lblk;
 151                         len = map.m_len;
 152
 153                         err = ext4_map_blocks(NULL, inode, &map, 0);
 154                         /*
 155                          * 'err==len' means that all of blocks has
 156                          * been preallocated no matter they are
 157                          * initialized or not.  For excluding
 158                          * unwritten extents, we need to check
 159                          * m_flags.  There are two conditions that
 160                          * indicate for initialized extents.  1) If we
 161                          * hit extent cache, EXT4_MAP_MAPPED flag is
 162                          * returned; 2) If we do a real lookup,
 163                          * non-flags are returned.  So we should check
 164                          * these two conditions.
 165                          */
 166                         if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
 167                                 overwrite = 1;
 168                 }
 169         }
 170
 171         ret = __generic_file_write_iter(iocb, from);
 172         mutex_unlock(&inode->i_mutex);
 173
 174         if (ret > 0) {
 175                 ssize_t err;
 176
 177                 err = generic_write_sync(file, iocb->ki_pos - ret, ret);
 178                 if (err < 0)
 179                         ret = err;
 180         }
 181         if (o_direct)
 182                 blk_finish_plug(&plug);
 183
 184         if (aio_mutex)
 185                 mutex_unlock(aio_mutex);
 186         return ret;
 187
 188 out:
 189         mutex_unlock(&inode->i_mutex);
 190         if (aio_mutex)
 191                 mutex_unlock(aio_mutex);
 192         return ret;
 193 }
 194
 195 #ifdef CONFIG_FS_DAX
 196 static void ext4_end_io_unwritten(struct buffer_head *bh, int uptodate)
 197 {
 198         struct inode *inode = bh->b_assoc_map->host;
 199         /* XXX: breaks on 32-bit > 16TB. Is that even supported? */
 200         loff_t offset = (loff_t)(uintptr_t)bh->b_private << inode->i_blkbits;
 201         int err;
 202         if (!uptodate)
 203                 return;
 204         WARN_ON(!buffer_unwritten(bh));
 205         err = ext4_convert_unwritten_extents(NULL, inode, offset, bh->b_size);
 206 }
 207
 208 static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 209 {
 210         int result;
 211         handle_t *handle = NULL;
 212         struct super_block *sb = file_inode(vma->vm_file)->i_sb;
 213         bool write = vmf->flags & FAULT_FLAG_WRITE;
 214
 215         if (write) {
 216                 sb_start_pagefault(sb);
 217                 file_update_time(vma->vm_file);
 218                 handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
 219                                                 EXT4_DATA_TRANS_BLOCKS(sb));
 220         }
 221
 222         if (IS_ERR(handle))
 223                 result = VM_FAULT_SIGBUS;
 224         else
 225                 result = __dax_fault(vma, vmf, ext4_get_block_dax,
 226                                                 ext4_end_io_unwritten);
 227
 228         if (write) {
 229                 if (!IS_ERR(handle))
 230                         ext4_journal_stop(handle);
 231                 sb_end_pagefault(sb);
 232         }
 233
 234         return result;
 235 }
 236
 237 static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
 238                                                 pmd_t *pmd, unsigned int flags)
 239 {
 240         int result;
 241         handle_t *handle = NULL;
 242         struct inode *inode = file_inode(vma->vm_file);
 243         struct super_block *sb = inode->i_sb;
 244         bool write = flags & FAULT_FLAG_WRITE;
 245
 246         if (write) {
 247                 sb_start_pagefault(sb);
 248                 file_update_time(vma->vm_file);
 249                 handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
 250                                 ext4_chunk_trans_blocks(inode,
 251                                                         PMD_SIZE / PAGE_SIZE));
 252         }
 253
 254         if (IS_ERR(handle))
 255                 result = VM_FAULT_SIGBUS;
 256         else
 257                 result = __dax_pmd_fault(vma, addr, pmd, flags,
 258                                 ext4_get_block_dax, ext4_end_io_unwritten);
 259
 260         if (write) {
 261                 if (!IS_ERR(handle))
 262                         ext4_journal_stop(handle);
 263                 sb_end_pagefault(sb);
 264         }
 265
 266         return result;
 267 }
 268
 269 static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 270 {
 271         return dax_mkwrite(vma, vmf, ext4_get_block_dax,
 272                                 ext4_end_io_unwritten);
 273 }
 274
 275 static const struct vm_operations_struct ext4_dax_vm_ops = {
 276         .fault          = ext4_dax_fault,
 277         .pmd_fault      = ext4_dax_pmd_fault,
 278         .page_mkwrite   = ext4_dax_mkwrite,
 279         .pfn_mkwrite    = dax_pfn_mkwrite,
 280 };
 281 #else
 282 #define ext4_dax_vm_ops ext4_file_vm_ops
 283 #endif
 284
 285 static const struct vm_operations_struct ext4_file_vm_ops = {
 286         .fault          = filemap_fault,
 287         .map_pages      = filemap_map_pages,
 288         .page_mkwrite   = ext4_page_mkwrite,
 289 };
 290
 291 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 292 {
 293         struct inode *inode = file->f_mapping->host;
 294
 295         if (ext4_encrypted_inode(inode)) {
 296                 int err = ext4_get_encryption_info(inode);
 297                 if (err)
 298                         return 0;
 299                 if (ext4_encryption_info(inode) == NULL)
 300                         return -ENOKEY;
 301         }
 302         file_accessed(file);
 303         if (IS_DAX(file_inode(file))) {
 304                 vma->vm_ops = &ext4_dax_vm_ops;
 305                 vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
 306         } else {
 307                 vma->vm_ops = &ext4_file_vm_ops;
 308         }
 309         return 0;
 310 }
 311
 312 static int ext4_file_open(struct inode * inode, struct file * filp)
 313 {
 314         struct super_block *sb = inode->i_sb;
 315         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 316         struct vfsmount *mnt = filp->f_path.mnt;
 317         struct path path;
 318         char buf[64], *cp;
 319         int ret;
 320
 321         if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
 322                      !(sb->s_flags & MS_RDONLY))) {
 323                 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
 324                 /*
 325                  * Sample where the filesystem has been mounted and
 326                  * store it in the superblock for sysadmin convenience
 327                  * when trying to sort through large numbers of block
 328                  * devices or filesystem images.
 329                  */
 330                 memset(buf, 0, sizeof(buf));
 331                 path.mnt = mnt;
 332                 path.dentry = mnt->mnt_root;
 333                 cp = d_path(&path, buf, sizeof(buf));
 334                 if (!IS_ERR(cp)) {
 335                         handle_t *handle;
 336                         int err;
 337
 338                         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
 339                         if (IS_ERR(handle))
 340                                 return PTR_ERR(handle);
 341                         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 342                         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
 343                         if (err) {
 344                                 ext4_journal_stop(handle);
 345                                 return err;
 346                         }
 347                         strlcpy(sbi->s_es->s_last_mounted, cp,
 348                                 sizeof(sbi->s_es->s_last_mounted));
 349                         ext4_handle_dirty_super(handle, sb);
 350                         ext4_journal_stop(handle);
 351                 }
 352         }
 353         if (ext4_encrypted_inode(inode)) {
 354                 ret = ext4_get_encryption_info(inode);
 355                 if (ret)
 356                         return -EACCES;
 357                 if (ext4_encryption_info(inode) == NULL)
 358                         return -ENOKEY;
 359         }
 360         /*
 361          * Set up the jbd2_inode if we are opening the inode for
 362          * writing and the journal is present
 363          */
 364         if (filp->f_mode & FMODE_WRITE) {
 365                 ret = ext4_inode_attach_jinode(inode);
 366                 if (ret < 0)
 367                         return ret;
 368         }
 369         return dquot_file_open(inode, filp);
 370 }
 371
 372 /*
 373  * Here we use ext4_map_blocks() to get a block mapping for a extent-based
 374  * file rather than ext4_ext_walk_space() because we can introduce
 375  * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same
 376  * function.  When extent status tree has been fully implemented, it will
 377  * track all extent status for a file and we can directly use it to
 378  * retrieve the offset for SEEK_DATA/SEEK_HOLE.
 379  */
 380
 381 /*
 382  * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to
 383  * lookup page cache to check whether or not there has some data between
 384  * [startoff, endoff] because, if this range contains an unwritten extent,
 385  * we determine this extent as a data or a hole according to whether the
 386  * page cache has data or not.
 387  */
 388 static int ext4_find_unwritten_pgoff(struct inode *inode,
 389                                      int whence,
 390                                      struct ext4_map_blocks *map,
 391                                      loff_t *offset)
 392 {
 393         struct pagevec pvec;
 394         unsigned int blkbits;
 395         pgoff_t index;
 396         pgoff_t end;
 397         loff_t endoff;
 398         loff_t startoff;
 399         loff_t lastoff;
 400         int found = 0;
 401
 402         blkbits = inode->i_sb->s_blocksize_bits;
 403         startoff = *offset;
 404         lastoff = startoff;
 405         endoff = (loff_t)(map->m_lblk + map->m_len) << blkbits;
 406
 407         index = startoff >> PAGE_CACHE_SHIFT;
 408         end = endoff >> PAGE_CACHE_SHIFT;
 409
 410         pagevec_init(&pvec, 0);
 411         do {
 412                 int i, num;
 413                 unsigned long nr_pages;
 414
 415                 num = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
 416                 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
 417                                           (pgoff_t)num);
 418                 if (nr_pages == 0) {
 419                         if (whence == SEEK_DATA)
 420                                 break;
 421
 422                         BUG_ON(whence != SEEK_HOLE);
 423                         /*
 424                          * If this is the first time to go into the loop and
 425                          * offset is not beyond the end offset, it will be a
 426                          * hole at this offset
 427                          */
 428                         if (lastoff == startoff || lastoff < endoff)
 429                                 found = 1;
 430                         break;
 431                 }
 432
 433                 /*
 434                  * If this is the first time to go into the loop and
 435                  * offset is smaller than the first page offset, it will be a
 436                  * hole at this offset.
 437                  */
 438                 if (lastoff == startoff && whence == SEEK_HOLE &&
 439                     lastoff < page_offset(pvec.pages[0])) {
 440                         found = 1;
 441                         break;
 442                 }
 443
 444                 for (i = 0; i < nr_pages; i++) {
 445                         struct page *page = pvec.pages[i];
 446                         struct buffer_head *bh, *head;
 447
 448                         /*
 449                          * If the current offset is not beyond the end of given
 450                          * range, it will be a hole.
 451                          */
 452                         if (lastoff < endoff && whence == SEEK_HOLE &&
 453                             page->index > end) {
 454                                 found = 1;
 455                                 *offset = lastoff;
 456                                 goto out;
 457                         }
 458
 459                         lock_page(page);
 460
 461                         if (unlikely(page->mapping != inode->i_mapping)) {
 462                                 unlock_page(page);
 463                                 continue;
 464                         }
 465
 466                         if (!page_has_buffers(page)) {
 467                                 unlock_page(page);
 468                                 continue;
 469                         }
 470
 471                         if (page_has_buffers(page)) {
 472                                 lastoff = page_offset(page);
 473                                 bh = head = page_buffers(page);
 474                                 do {
 475                                         if (buffer_uptodate(bh) ||
 476                                             buffer_unwritten(bh)) {
 477                                                 if (whence == SEEK_DATA)
 478                                                         found = 1;
 479                                         } else {
 480                                                 if (whence == SEEK_HOLE)
 481                                                         found = 1;
 482                                         }
 483                                         if (found) {
 484                                                 *offset = max_t(loff_t,
 485                                                         startoff, lastoff);
 486                                                 unlock_page(page);
 487                                                 goto out;
 488                                         }
 489                                         lastoff += bh->b_size;
 490                                         bh = bh->b_this_page;
 491                                 } while (bh != head);
 492                         }
 493
 494                         lastoff = page_offset(page) + PAGE_SIZE;
 495                         unlock_page(page);
 496                 }
 497
 498                 /*
 499                  * The no. of pages is less than our desired, that would be a
 500                  * hole in there.
 501                  */
 502                 if (nr_pages < num && whence == SEEK_HOLE) {
 503                         found = 1;
 504                         *offset = lastoff;
 505                         break;
 506                 }
 507
 508                 index = pvec.pages[i - 1]->index + 1;
 509                 pagevec_release(&pvec);
 510         } while (index <= end);
 511
 512 out:
 513         pagevec_release(&pvec);
 514         return found;
 515 }
 516
 517 /*
 518  * ext4_seek_data() retrieves the offset for SEEK_DATA.
 519  */
 520 static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
 521 {
 522         struct inode *inode = file->f_mapping->host;
 523         struct ext4_map_blocks map;
 524         struct extent_status es;
 525         ext4_lblk_t start, last, end;
 526         loff_t dataoff, isize;
 527         int blkbits;
 528         int ret = 0;
 529
 530         mutex_lock(&inode->i_mutex);
 531
 532         isize = i_size_read(inode);
 533         if (offset >= isize) {
 534                 mutex_unlock(&inode->i_mutex);
 535                 return -ENXIO;
 536         }
 537
 538         blkbits = inode->i_sb->s_blocksize_bits;
 539         start = offset >> blkbits;
 540         last = start;
 541         end = isize >> blkbits;
 542         dataoff = offset;
 543
 544         do {
 545                 map.m_lblk = last;
 546                 map.m_len = end - last + 1;
 547                 ret = ext4_map_blocks(NULL, inode, &map, 0);
 548                 if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {
 549                         if (last != start)
 550                                 dataoff = (loff_t)last << blkbits;
 551                         break;
 552                 }
 553
 554                 /*
 555                  * If there is a delay extent at this offset,
 556                  * it will be as a data.
 557                  */
 558                 ext4_es_find_delayed_extent_range(inode, last, last, &es);
 559                 if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
 560                         if (last != start)
 561                                 dataoff = (loff_t)last << blkbits;
 562                         break;
 563                 }
 564
 565                 /*
 566                  * If there is a unwritten extent at this offset,
 567                  * it will be as a data or a hole according to page
 568                  * cache that has data or not.
 569                  */
 570                 if (map.m_flags & EXT4_MAP_UNWRITTEN) {
 571                         int unwritten;
 572                         unwritten = ext4_find_unwritten_pgoff(inode, SEEK_DATA,
 573                                                               &map, &dataoff);
 574                         if (unwritten)
 575                                 break;
 576                 }
 577
 578                 last++;
 579                 dataoff = (loff_t)last << blkbits;
 580         } while (last <= end);
 581
 582         mutex_unlock(&inode->i_mutex);
 583
 584         if (dataoff > isize)
 585                 return -ENXIO;
 586
 587         return vfs_setpos(file, dataoff, maxsize);
 588 }
 589
 590 /*
 591  * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
 592  */
 593 static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
 594 {
 595         struct inode *inode = file->f_mapping->host;
 596         struct ext4_map_blocks map;
 597         struct extent_status es;
 598         ext4_lblk_t start, last, end;
 599         loff_t holeoff, isize;
 600         int blkbits;
 601         int ret = 0;
 602
 603         mutex_lock(&inode->i_mutex);
 604
 605         isize = i_size_read(inode);
 606         if (offset >= isize) {
 607                 mutex_unlock(&inode->i_mutex);
 608                 return -ENXIO;
 609         }
 610
 611         blkbits = inode->i_sb->s_blocksize_bits;
 612         start = offset >> blkbits;
 613         last = start;
 614         end = isize >> blkbits;
 615         holeoff = offset;
 616
 617         do {
 618                 map.m_lblk = last;
 619                 map.m_len = end - last + 1;
 620                 ret = ext4_map_blocks(NULL, inode, &map, 0);
 621                 if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {
 622                         last += ret;
 623                         holeoff = (loff_t)last << blkbits;
 624                         continue;
 625                 }
 626
 627                 /*
 628                  * If there is a delay extent at this offset,
 629                  * we will skip this extent.
 630                  */
 631                 ext4_es_find_delayed_extent_range(inode, last, last, &es);
 632                 if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
 633                         last = es.es_lblk + es.es_len;
 634                         holeoff = (loff_t)last << blkbits;
 635                         continue;
 636                 }
 637
 638                 /*
 639                  * If there is a unwritten extent at this offset,
 640                  * it will be as a data or a hole according to page
 641                  * cache that has data or not.
 642                  */
 643                 if (map.m_flags & EXT4_MAP_UNWRITTEN) {
 644                         int unwritten;
 645                         unwritten = ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
 646                                                               &map, &holeoff);
 647                         if (!unwritten) {
 648                                 last += ret;
 649                                 holeoff = (loff_t)last << blkbits;
 650                                 continue;
 651                         }
 652                 }
 653
 654                 /* find a hole */
 655                 break;
 656         } while (last <= end);
 657
 658         mutex_unlock(&inode->i_mutex);
 659
 660         if (holeoff > isize)
 661                 holeoff = isize;
 662
 663         return vfs_setpos(file, holeoff, maxsize);
 664 }
 665
 666 /*
 667  * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
 668  * by calling generic_file_llseek_size() with the appropriate maxbytes
 669  * value for each.
 670  */
 671 loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
 672 {
 673         struct inode *inode = file->f_mapping->host;
 674         loff_t maxbytes;
 675
 676         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
 677                 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
 678         else
 679                 maxbytes = inode->i_sb->s_maxbytes;
 680
 681         switch (whence) {
 682         case SEEK_SET:
 683         case SEEK_CUR:
 684         case SEEK_END:
 685                 return generic_file_llseek_size(file, offset, whence,
 686                                                 maxbytes, i_size_read(inode));
 687         case SEEK_DATA:
 688                 return ext4_seek_data(file, offset, maxbytes);
 689         case SEEK_HOLE:
 690                 return ext4_seek_hole(file, offset, maxbytes);
 691         }
 692
 693         return -EINVAL;
 694 }
 695
 696 const struct file_operations ext4_file_operations = {
 697         .llseek         = ext4_llseek,
 698         .read_iter      = generic_file_read_iter,
 699         .write_iter     = ext4_file_write_iter,
 700         .unlocked_ioctl = ext4_ioctl,
 701 #ifdef CONFIG_COMPAT
 702         .compat_ioctl   = ext4_compat_ioctl,
 703 #endif
 704         .mmap           = ext4_file_mmap,
 705         .open           = ext4_file_open,
 706         .release        = ext4_release_file,
 707         .fsync          = ext4_sync_file,
 708         .splice_read    = generic_file_splice_read,
 709         .splice_write   = iter_file_splice_write,
 710         .fallocate      = ext4_fallocate,
 711 };
 712
 713 const struct inode_operations ext4_file_inode_operations = {
 714         .setattr        = ext4_setattr,
 715         .getattr        = ext4_getattr,
 716         .setxattr       = generic_setxattr,
 717         .getxattr       = generic_getxattr,
 718         .listxattr      = ext4_listxattr,
 719         .removexattr    = generic_removexattr,
 720         .get_acl        = ext4_get_acl,
 721         .set_acl        = ext4_set_acl,
 722         .fiemap         = ext4_fiemap,
 723 };
 724