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 blk_plug plug;
  97         int o_direct = iocb->ki_flags & IOCB_DIRECT;
  98         int unaligned_aio = 0;
  99         int overwrite = 0;
 100         ssize_t ret;
 101
 102         inode_lock(inode);
 103         ret = generic_write_checks(iocb, from);
 104         if (ret <= 0)
 105                 goto out;
 106
 107         /*
 108          * Unaligned direct AIO must be serialized among each other as zeroing
 109          * of partial blocks of two competing unaligned AIOs can result in data
 110          * corruption.
 111          */
 112         if (o_direct && ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
 113             !is_sync_kiocb(iocb) &&
 114             ext4_unaligned_aio(inode, from, iocb->ki_pos)) {
 115                 unaligned_aio = 1;
 116                 ext4_unwritten_wait(inode);
 117         }
 118
 119         /*
 120          * If we have encountered a bitmap-format file, the size limit
 121          * is smaller than s_maxbytes, which is for extent-mapped files.
 122          */
 123         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
 124                 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 125
 126                 if (iocb->ki_pos >= sbi->s_bitmap_maxbytes) {
 127                         ret = -EFBIG;
 128                         goto out;
 129                 }
 130                 iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
 131         }
 132
 133         iocb->private = &overwrite;
 134         if (o_direct) {
 135                 size_t length = iov_iter_count(from);
 136                 loff_t pos = iocb->ki_pos;
 137                 blk_start_plug(&plug);
 138
 139                 /* check whether we do a DIO overwrite or not */
 140                 if (ext4_should_dioread_nolock(inode) && !unaligned_aio &&
 141                     !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) {
 142                         struct ext4_map_blocks map;
 143                         unsigned int blkbits = inode->i_blkbits;
 144                         int err, len;
 145
 146                         map.m_lblk = pos >> blkbits;
 147                         map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits)
 148                                 - map.m_lblk;
 149                         len = map.m_len;
 150
 151                         err = ext4_map_blocks(NULL, inode, &map, 0);
 152                         /*
 153                          * 'err==len' means that all of blocks has
 154                          * been preallocated no matter they are
 155                          * initialized or not.  For excluding
 156                          * unwritten extents, we need to check
 157                          * m_flags.  There are two conditions that
 158                          * indicate for initialized extents.  1) If we
 159                          * hit extent cache, EXT4_MAP_MAPPED flag is
 160                          * returned; 2) If we do a real lookup,
 161                          * non-flags are returned.  So we should check
 162                          * these two conditions.
 163                          */
 164                         if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
 165                                 overwrite = 1;
 166                 }
 167         }
 168
 169         ret = __generic_file_write_iter(iocb, from);
 170         inode_unlock(inode);
 171
 172         if (ret > 0) {
 173                 ssize_t err;
 174
 175                 err = generic_write_sync(file, iocb->ki_pos - ret, ret);
 176                 if (err < 0)
 177                         ret = err;
 178         }
 179         if (o_direct)
 180                 blk_finish_plug(&plug);
 181
 182         return ret;
 183
 184 out:
 185         inode_unlock(inode);
 186         return ret;
 187 }
 188
 189 #ifdef CONFIG_FS_DAX
 190 static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 191 {
 192         int result;
 193         handle_t *handle = NULL;
 194         struct inode *inode = file_inode(vma->vm_file);
 195         struct super_block *sb = inode->i_sb;
 196         bool write = vmf->flags & FAULT_FLAG_WRITE;
 197
 198         if (write) {
 199                 sb_start_pagefault(sb);
 200                 file_update_time(vma->vm_file);
 201                 down_read(&EXT4_I(inode)->i_mmap_sem);
 202                 handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
 203                                                 EXT4_DATA_TRANS_BLOCKS(sb));
 204         } else
 205                 down_read(&EXT4_I(inode)->i_mmap_sem);
 206
 207         if (IS_ERR(handle))
 208                 result = VM_FAULT_SIGBUS;
 209         else
 210                 result = __dax_fault(vma, vmf, ext4_dax_get_block, NULL);
 211
 212         if (write) {
 213                 if (!IS_ERR(handle))
 214                         ext4_journal_stop(handle);
 215                 up_read(&EXT4_I(inode)->i_mmap_sem);
 216                 sb_end_pagefault(sb);
 217         } else
 218                 up_read(&EXT4_I(inode)->i_mmap_sem);
 219
 220         return result;
 221 }
 222
 223 static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
 224                                                 pmd_t *pmd, unsigned int flags)
 225 {
 226         int result;
 227         handle_t *handle = NULL;
 228         struct inode *inode = file_inode(vma->vm_file);
 229         struct super_block *sb = inode->i_sb;
 230         bool write = flags & FAULT_FLAG_WRITE;
 231
 232         if (write) {
 233                 sb_start_pagefault(sb);
 234                 file_update_time(vma->vm_file);
 235                 down_read(&EXT4_I(inode)->i_mmap_sem);
 236                 handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
 237                                 ext4_chunk_trans_blocks(inode,
 238                                                         PMD_SIZE / PAGE_SIZE));
 239         } else
 240                 down_read(&EXT4_I(inode)->i_mmap_sem);
 241
 242         if (IS_ERR(handle))
 243                 result = VM_FAULT_SIGBUS;
 244         else
 245                 result = __dax_pmd_fault(vma, addr, pmd, flags,
 246                                          ext4_dax_get_block, NULL);
 247
 248         if (write) {
 249                 if (!IS_ERR(handle))
 250                         ext4_journal_stop(handle);
 251                 up_read(&EXT4_I(inode)->i_mmap_sem);
 252                 sb_end_pagefault(sb);
 253         } else
 254                 up_read(&EXT4_I(inode)->i_mmap_sem);
 255
 256         return result;
 257 }
 258
 259 /*
 260  * Handle write fault for VM_MIXEDMAP mappings. Similarly to ext4_dax_fault()
 261  * handler we check for races agaist truncate. Note that since we cycle through
 262  * i_mmap_sem, we are sure that also any hole punching that began before we
 263  * were called is finished by now and so if it included part of the file we
 264  * are working on, our pte will get unmapped and the check for pte_same() in
 265  * wp_pfn_shared() fails. Thus fault gets retried and things work out as
 266  * desired.
 267  */
 268 static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma,
 269                                 struct vm_fault *vmf)
 270 {
 271         struct inode *inode = file_inode(vma->vm_file);
 272         struct super_block *sb = inode->i_sb;
 273         loff_t size;
 274         int ret;
 275
 276         sb_start_pagefault(sb);
 277         file_update_time(vma->vm_file);
 278         down_read(&EXT4_I(inode)->i_mmap_sem);
 279         size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
 280         if (vmf->pgoff >= size)
 281                 ret = VM_FAULT_SIGBUS;
 282         else
 283                 ret = dax_pfn_mkwrite(vma, vmf);
 284         up_read(&EXT4_I(inode)->i_mmap_sem);
 285         sb_end_pagefault(sb);
 286
 287         return ret;
 288 }
 289
 290 static const struct vm_operations_struct ext4_dax_vm_ops = {
 291         .fault          = ext4_dax_fault,
 292         .pmd_fault      = ext4_dax_pmd_fault,
 293         .page_mkwrite   = ext4_dax_fault,
 294         .pfn_mkwrite    = ext4_dax_pfn_mkwrite,
 295 };
 296 #else
 297 #define ext4_dax_vm_ops ext4_file_vm_ops
 298 #endif
 299
 300 static const struct vm_operations_struct ext4_file_vm_ops = {
 301         .fault          = ext4_filemap_fault,
 302         .map_pages      = filemap_map_pages,
 303         .page_mkwrite   = ext4_page_mkwrite,
 304 };
 305
 306 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 307 {
 308         struct inode *inode = file->f_mapping->host;
 309
 310         if (ext4_encrypted_inode(inode)) {
 311                 int err = ext4_get_encryption_info(inode);
 312                 if (err)
 313                         return 0;
 314                 if (ext4_encryption_info(inode) == NULL)
 315                         return -ENOKEY;
 316         }
 317         file_accessed(file);
 318         if (IS_DAX(file_inode(file))) {
 319                 vma->vm_ops = &ext4_dax_vm_ops;
 320                 vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
 321         } else {
 322                 vma->vm_ops = &ext4_file_vm_ops;
 323         }
 324         return 0;
 325 }
 326
 327 static int ext4_file_open(struct inode * inode, struct file * filp)
 328 {
 329         struct super_block *sb = inode->i_sb;
 330         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 331         struct vfsmount *mnt = filp->f_path.mnt;
 332         struct dentry *dir;
 333         struct path path;
 334         char buf[64], *cp;
 335         int ret;
 336
 337         if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
 338                      !(sb->s_flags & MS_RDONLY))) {
 339                 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
 340                 /*
 341                  * Sample where the filesystem has been mounted and
 342                  * store it in the superblock for sysadmin convenience
 343                  * when trying to sort through large numbers of block
 344                  * devices or filesystem images.
 345                  */
 346                 memset(buf, 0, sizeof(buf));
 347                 path.mnt = mnt;
 348                 path.dentry = mnt->mnt_root;
 349                 cp = d_path(&path, buf, sizeof(buf));
 350                 if (!IS_ERR(cp)) {
 351                         handle_t *handle;
 352                         int err;
 353
 354                         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
 355                         if (IS_ERR(handle))
 356                                 return PTR_ERR(handle);
 357                         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 358                         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
 359                         if (err) {
 360                                 ext4_journal_stop(handle);
 361                                 return err;
 362                         }
 363                         strlcpy(sbi->s_es->s_last_mounted, cp,
 364                                 sizeof(sbi->s_es->s_last_mounted));
 365                         ext4_handle_dirty_super(handle, sb);
 366                         ext4_journal_stop(handle);
 367                 }
 368         }
 369         if (ext4_encrypted_inode(inode)) {
 370                 ret = ext4_get_encryption_info(inode);
 371                 if (ret)
 372                         return -EACCES;
 373                 if (ext4_encryption_info(inode) == NULL)
 374                         return -ENOKEY;
 375         }
 376
 377         dir = dget_parent(file_dentry(filp));
 378         if (ext4_encrypted_inode(d_inode(dir)) &&
 379             !ext4_is_child_context_consistent_with_parent(d_inode(dir), inode)) {
 380                 ext4_warning(inode->i_sb,
 381                              "Inconsistent encryption contexts: %lu/%lu",
 382                              (unsigned long) d_inode(dir)->i_ino,
 383                              (unsigned long) inode->i_ino);
 384                 dput(dir);
 385                 return -EPERM;
 386         }
 387         dput(dir);
 388         /*
 389          * Set up the jbd2_inode if we are opening the inode for
 390          * writing and the journal is present
 391          */
 392         if (filp->f_mode & FMODE_WRITE) {
 393                 ret = ext4_inode_attach_jinode(inode);
 394                 if (ret < 0)
 395                         return ret;
 396         }
 397         return dquot_file_open(inode, filp);
 398 }
 399
 400 /*
 401  * Here we use ext4_map_blocks() to get a block mapping for a extent-based
 402  * file rather than ext4_ext_walk_space() because we can introduce
 403  * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same
 404  * function.  When extent status tree has been fully implemented, it will
 405  * track all extent status for a file and we can directly use it to
 406  * retrieve the offset for SEEK_DATA/SEEK_HOLE.
 407  */
 408
 409 /*
 410  * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to
 411  * lookup page cache to check whether or not there has some data between
 412  * [startoff, endoff] because, if this range contains an unwritten extent,
 413  * we determine this extent as a data or a hole according to whether the
 414  * page cache has data or not.
 415  */
 416 static int ext4_find_unwritten_pgoff(struct inode *inode,
 417                                      int whence,
 418                                      ext4_lblk_t end_blk,
 419                                      loff_t *offset)
 420 {
 421         struct pagevec pvec;
 422         unsigned int blkbits;
 423         pgoff_t index;
 424         pgoff_t end;
 425         loff_t endoff;
 426         loff_t startoff;
 427         loff_t lastoff;
 428         int found = 0;
 429
 430         blkbits = inode->i_sb->s_blocksize_bits;
 431         startoff = *offset;
 432         lastoff = startoff;
 433         endoff = (loff_t)end_blk << blkbits;
 434
 435         index = startoff >> PAGE_SHIFT;
 436         end = endoff >> PAGE_SHIFT;
 437
 438         pagevec_init(&pvec, 0);
 439         do {
 440                 int i, num;
 441                 unsigned long nr_pages;
 442
 443                 num = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
 444                 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
 445                                           (pgoff_t)num);
 446                 if (nr_pages == 0) {
 447                         if (whence == SEEK_DATA)
 448                                 break;
 449
 450                         BUG_ON(whence != SEEK_HOLE);
 451                         /*
 452                          * If this is the first time to go into the loop and
 453                          * offset is not beyond the end offset, it will be a
 454                          * hole at this offset
 455                          */
 456                         if (lastoff == startoff || lastoff < endoff)
 457                                 found = 1;
 458                         break;
 459                 }
 460
 461                 /*
 462                  * If this is the first time to go into the loop and
 463                  * offset is smaller than the first page offset, it will be a
 464                  * hole at this offset.
 465                  */
 466                 if (lastoff == startoff && whence == SEEK_HOLE &&
 467                     lastoff < page_offset(pvec.pages[0])) {
 468                         found = 1;
 469                         break;
 470                 }
 471
 472                 for (i = 0; i < nr_pages; i++) {
 473                         struct page *page = pvec.pages[i];
 474                         struct buffer_head *bh, *head;
 475
 476                         /*
 477                          * If the current offset is not beyond the end of given
 478                          * range, it will be a hole.
 479                          */
 480                         if (lastoff < endoff && whence == SEEK_HOLE &&
 481                             page->index > end) {
 482                                 found = 1;
 483                                 *offset = lastoff;
 484                                 goto out;
 485                         }
 486
 487                         lock_page(page);
 488
 489                         if (unlikely(page->mapping != inode->i_mapping)) {
 490                                 unlock_page(page);
 491                                 continue;
 492                         }
 493
 494                         if (!page_has_buffers(page)) {
 495                                 unlock_page(page);
 496                                 continue;
 497                         }
 498
 499                         if (page_has_buffers(page)) {
 500                                 lastoff = page_offset(page);
 501                                 bh = head = page_buffers(page);
 502                                 do {
 503                                         if (buffer_uptodate(bh) ||
 504                                             buffer_unwritten(bh)) {
 505                                                 if (whence == SEEK_DATA)
 506                                                         found = 1;
 507                                         } else {
 508                                                 if (whence == SEEK_HOLE)
 509                                                         found = 1;
 510                                         }
 511                                         if (found) {
 512                                                 *offset = max_t(loff_t,
 513                                                         startoff, lastoff);
 514                                                 unlock_page(page);
 515                                                 goto out;
 516                                         }
 517                                         lastoff += bh->b_size;
 518                                         bh = bh->b_this_page;
 519                                 } while (bh != head);
 520                         }
 521
 522                         lastoff = page_offset(page) + PAGE_SIZE;
 523                         unlock_page(page);
 524                 }
 525
 526                 /*
 527                  * The no. of pages is less than our desired, that would be a
 528                  * hole in there.
 529                  */
 530                 if (nr_pages < num && whence == SEEK_HOLE) {
 531                         found = 1;
 532                         *offset = lastoff;
 533                         break;
 534                 }
 535
 536                 index = pvec.pages[i - 1]->index + 1;
 537                 pagevec_release(&pvec);
 538         } while (index <= end);
 539
 540 out:
 541         pagevec_release(&pvec);
 542         return found;
 543 }
 544
 545 /*
 546  * ext4_seek_data() retrieves the offset for SEEK_DATA.
 547  */
 548 static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
 549 {
 550         struct inode *inode = file->f_mapping->host;
 551         struct extent_status es;
 552         ext4_lblk_t start, last, end;
 553         loff_t dataoff, isize;
 554         int blkbits;
 555         int ret;
 556
 557         inode_lock(inode);
 558
 559         isize = i_size_read(inode);
 560         if (offset >= isize) {
 561                 inode_unlock(inode);
 562                 return -ENXIO;
 563         }
 564
 565         blkbits = inode->i_sb->s_blocksize_bits;
 566         start = offset >> blkbits;
 567         last = start;
 568         end = isize >> blkbits;
 569         dataoff = offset;
 570
 571         do {
 572                 ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
 573                 if (ret <= 0) {
 574                         /* No extent found -> no data */
 575                         if (ret == 0)
 576                                 ret = -ENXIO;
 577                         inode_unlock(inode);
 578                         return ret;
 579                 }
 580
 581                 last = es.es_lblk;
 582                 if (last != start)
 583                         dataoff = (loff_t)last << blkbits;
 584                 if (!ext4_es_is_unwritten(&es))
 585                         break;
 586
 587                 /*
 588                  * If there is a unwritten extent at this offset,
 589                  * it will be as a data or a hole according to page
 590                  * cache that has data or not.
 591                  */
 592                 if (ext4_find_unwritten_pgoff(inode, SEEK_DATA,
 593                                               es.es_lblk + es.es_len, &dataoff))
 594                         break;
 595                 last += es.es_len;
 596                 dataoff = (loff_t)last << blkbits;
 597                 cond_resched();
 598         } while (last <= end);
 599
 600         inode_unlock(inode);
 601
 602         if (dataoff > isize)
 603                 return -ENXIO;
 604
 605         return vfs_setpos(file, dataoff, maxsize);
 606 }
 607
 608 /*
 609  * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
 610  */
 611 static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
 612 {
 613         struct inode *inode = file->f_mapping->host;
 614         struct extent_status es;
 615         ext4_lblk_t start, last, end;
 616         loff_t holeoff, isize;
 617         int blkbits;
 618         int ret;
 619
 620         inode_lock(inode);
 621
 622         isize = i_size_read(inode);
 623         if (offset >= isize) {
 624                 inode_unlock(inode);
 625                 return -ENXIO;
 626         }
 627
 628         blkbits = inode->i_sb->s_blocksize_bits;
 629         start = offset >> blkbits;
 630         last = start;
 631         end = isize >> blkbits;
 632         holeoff = offset;
 633
 634         do {
 635                 ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
 636                 if (ret < 0) {
 637                         inode_unlock(inode);
 638                         return ret;
 639                 }
 640                 /* Found a hole? */
 641                 if (ret == 0 || es.es_lblk > last) {
 642                         if (last != start)
 643                                 holeoff = (loff_t)last << blkbits;
 644                         break;
 645                 }
 646                 /*
 647                  * If there is a unwritten extent at this offset,
 648                  * it will be as a data or a hole according to page
 649                  * cache that has data or not.
 650                  */
 651                 if (ext4_es_is_unwritten(&es) &&
 652                     ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
 653                                               last + es.es_len, &holeoff))
 654                         break;
 655
 656                 last += es.es_len;
 657                 holeoff = (loff_t)last << blkbits;
 658                 cond_resched();
 659         } while (last <= end);
 660
 661         inode_unlock(inode);
 662
 663         if (holeoff > isize)
 664                 holeoff = isize;
 665
 666         return vfs_setpos(file, holeoff, maxsize);
 667 }
 668
 669 /*
 670  * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
 671  * by calling generic_file_llseek_size() with the appropriate maxbytes
 672  * value for each.
 673  */
 674 loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
 675 {
 676         struct inode *inode = file->f_mapping->host;
 677         loff_t maxbytes;
 678
 679         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
 680                 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
 681         else
 682                 maxbytes = inode->i_sb->s_maxbytes;
 683
 684         switch (whence) {
 685         case SEEK_SET:
 686         case SEEK_CUR:
 687         case SEEK_END:
 688                 return generic_file_llseek_size(file, offset, whence,
 689                                                 maxbytes, i_size_read(inode));
 690         case SEEK_DATA:
 691                 return ext4_seek_data(file, offset, maxbytes);
 692         case SEEK_HOLE:
 693                 return ext4_seek_hole(file, offset, maxbytes);
 694         }
 695
 696         return -EINVAL;
 697 }
 698
 699 const struct file_operations ext4_file_operations = {
 700         .llseek         = ext4_llseek,
 701         .read_iter      = generic_file_read_iter,
 702         .write_iter     = ext4_file_write_iter,
 703         .unlocked_ioctl = ext4_ioctl,
 704 #ifdef CONFIG_COMPAT
 705         .compat_ioctl   = ext4_compat_ioctl,
 706 #endif
 707         .mmap           = ext4_file_mmap,
 708         .open           = ext4_file_open,
 709         .release        = ext4_release_file,
 710         .fsync          = ext4_sync_file,
 711         .splice_read    = generic_file_splice_read,
 712         .splice_write   = iter_file_splice_write,
 713         .fallocate      = ext4_fallocate,
 714 };
 715
 716 const struct inode_operations ext4_file_inode_operations = {
 717         .setattr        = ext4_setattr,
 718         .getattr        = ext4_getattr,
 719         .setxattr       = generic_setxattr,
 720         .getxattr       = generic_getxattr,
 721         .listxattr      = ext4_listxattr,
 722         .removexattr    = generic_removexattr,
 723         .get_acl        = ext4_get_acl,
 724         .set_acl        = ext4_set_acl,
 725         .fiemap         = ext4_fiemap,
 726 };
 727