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                 ret = generic_write_sync(iocb, ret);
 174         if (o_direct)
 175                 blk_finish_plug(&plug);
 176
 177         return ret;
 178
 179 out:
 180         inode_unlock(inode);
 181         return ret;
 182 }
 183
 184 #ifdef CONFIG_FS_DAX
 185 static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 186 {
 187         int result;
 188         handle_t *handle = NULL;
 189         struct inode *inode = file_inode(vma->vm_file);
 190         struct super_block *sb = inode->i_sb;
 191         bool write = vmf->flags & FAULT_FLAG_WRITE;
 192
 193         if (write) {
 194                 sb_start_pagefault(sb);
 195                 file_update_time(vma->vm_file);
 196                 down_read(&EXT4_I(inode)->i_mmap_sem);
 197                 handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
 198                                                 EXT4_DATA_TRANS_BLOCKS(sb));
 199         } else
 200                 down_read(&EXT4_I(inode)->i_mmap_sem);
 201
 202         if (IS_ERR(handle))
 203                 result = VM_FAULT_SIGBUS;
 204         else
 205                 result = __dax_fault(vma, vmf, ext4_dax_mmap_get_block, NULL);
 206
 207         if (write) {
 208                 if (!IS_ERR(handle))
 209                         ext4_journal_stop(handle);
 210                 up_read(&EXT4_I(inode)->i_mmap_sem);
 211                 sb_end_pagefault(sb);
 212         } else
 213                 up_read(&EXT4_I(inode)->i_mmap_sem);
 214
 215         return result;
 216 }
 217
 218 static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
 219                                                 pmd_t *pmd, unsigned int flags)
 220 {
 221         int result;
 222         handle_t *handle = NULL;
 223         struct inode *inode = file_inode(vma->vm_file);
 224         struct super_block *sb = inode->i_sb;
 225         bool write = flags & FAULT_FLAG_WRITE;
 226
 227         if (write) {
 228                 sb_start_pagefault(sb);
 229                 file_update_time(vma->vm_file);
 230                 down_read(&EXT4_I(inode)->i_mmap_sem);
 231                 handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
 232                                 ext4_chunk_trans_blocks(inode,
 233                                                         PMD_SIZE / PAGE_SIZE));
 234         } else
 235                 down_read(&EXT4_I(inode)->i_mmap_sem);
 236
 237         if (IS_ERR(handle))
 238                 result = VM_FAULT_SIGBUS;
 239         else
 240                 result = __dax_pmd_fault(vma, addr, pmd, flags,
 241                                 ext4_dax_mmap_get_block, NULL);
 242
 243         if (write) {
 244                 if (!IS_ERR(handle))
 245                         ext4_journal_stop(handle);
 246                 up_read(&EXT4_I(inode)->i_mmap_sem);
 247                 sb_end_pagefault(sb);
 248         } else
 249                 up_read(&EXT4_I(inode)->i_mmap_sem);
 250
 251         return result;
 252 }
 253
 254 /*
 255  * Handle write fault for VM_MIXEDMAP mappings. Similarly to ext4_dax_fault()
 256  * handler we check for races agaist truncate. Note that since we cycle through
 257  * i_mmap_sem, we are sure that also any hole punching that began before we
 258  * were called is finished by now and so if it included part of the file we
 259  * are working on, our pte will get unmapped and the check for pte_same() in
 260  * wp_pfn_shared() fails. Thus fault gets retried and things work out as
 261  * desired.
 262  */
 263 static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma,
 264                                 struct vm_fault *vmf)
 265 {
 266         struct inode *inode = file_inode(vma->vm_file);
 267         struct super_block *sb = inode->i_sb;
 268         loff_t size;
 269         int ret;
 270
 271         sb_start_pagefault(sb);
 272         file_update_time(vma->vm_file);
 273         down_read(&EXT4_I(inode)->i_mmap_sem);
 274         size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
 275         if (vmf->pgoff >= size)
 276                 ret = VM_FAULT_SIGBUS;
 277         else
 278                 ret = dax_pfn_mkwrite(vma, vmf);
 279         up_read(&EXT4_I(inode)->i_mmap_sem);
 280         sb_end_pagefault(sb);
 281
 282         return ret;
 283 }
 284
 285 static const struct vm_operations_struct ext4_dax_vm_ops = {
 286         .fault          = ext4_dax_fault,
 287         .pmd_fault      = ext4_dax_pmd_fault,
 288         .page_mkwrite   = ext4_dax_fault,
 289         .pfn_mkwrite    = ext4_dax_pfn_mkwrite,
 290 };
 291 #else
 292 #define ext4_dax_vm_ops ext4_file_vm_ops
 293 #endif
 294
 295 static const struct vm_operations_struct ext4_file_vm_ops = {
 296         .fault          = ext4_filemap_fault,
 297         .map_pages      = filemap_map_pages,
 298         .page_mkwrite   = ext4_page_mkwrite,
 299 };
 300
 301 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 302 {
 303         struct inode *inode = file->f_mapping->host;
 304
 305         if (ext4_encrypted_inode(inode)) {
 306                 int err = ext4_get_encryption_info(inode);
 307                 if (err)
 308                         return 0;
 309                 if (ext4_encryption_info(inode) == NULL)
 310                         return -ENOKEY;
 311         }
 312         file_accessed(file);
 313         if (IS_DAX(file_inode(file))) {
 314                 vma->vm_ops = &ext4_dax_vm_ops;
 315                 vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
 316         } else {
 317                 vma->vm_ops = &ext4_file_vm_ops;
 318         }
 319         return 0;
 320 }
 321
 322 static int ext4_file_open(struct inode * inode, struct file * filp)
 323 {
 324         struct super_block *sb = inode->i_sb;
 325         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 326         struct vfsmount *mnt = filp->f_path.mnt;
 327         struct dentry *dir;
 328         struct path path;
 329         char buf[64], *cp;
 330         int ret;
 331
 332         if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
 333                      !(sb->s_flags & MS_RDONLY))) {
 334                 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
 335                 /*
 336                  * Sample where the filesystem has been mounted and
 337                  * store it in the superblock for sysadmin convenience
 338                  * when trying to sort through large numbers of block
 339                  * devices or filesystem images.
 340                  */
 341                 memset(buf, 0, sizeof(buf));
 342                 path.mnt = mnt;
 343                 path.dentry = mnt->mnt_root;
 344                 cp = d_path(&path, buf, sizeof(buf));
 345                 if (!IS_ERR(cp)) {
 346                         handle_t *handle;
 347                         int err;
 348
 349                         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
 350                         if (IS_ERR(handle))
 351                                 return PTR_ERR(handle);
 352                         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 353                         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
 354                         if (err) {
 355                                 ext4_journal_stop(handle);
 356                                 return err;
 357                         }
 358                         strlcpy(sbi->s_es->s_last_mounted, cp,
 359                                 sizeof(sbi->s_es->s_last_mounted));
 360                         ext4_handle_dirty_super(handle, sb);
 361                         ext4_journal_stop(handle);
 362                 }
 363         }
 364         if (ext4_encrypted_inode(inode)) {
 365                 ret = ext4_get_encryption_info(inode);
 366                 if (ret)
 367                         return -EACCES;
 368                 if (ext4_encryption_info(inode) == NULL)
 369                         return -ENOKEY;
 370         }
 371
 372         dir = dget_parent(file_dentry(filp));
 373         if (ext4_encrypted_inode(d_inode(dir)) &&
 374             !ext4_is_child_context_consistent_with_parent(d_inode(dir), inode)) {
 375                 ext4_warning(inode->i_sb,
 376                              "Inconsistent encryption contexts: %lu/%lu\n",
 377                              (unsigned long) d_inode(dir)->i_ino,
 378                              (unsigned long) inode->i_ino);
 379                 dput(dir);
 380                 return -EPERM;
 381         }
 382         dput(dir);
 383         /*
 384          * Set up the jbd2_inode if we are opening the inode for
 385          * writing and the journal is present
 386          */
 387         if (filp->f_mode & FMODE_WRITE) {
 388                 ret = ext4_inode_attach_jinode(inode);
 389                 if (ret < 0)
 390                         return ret;
 391         }
 392         return dquot_file_open(inode, filp);
 393 }
 394
 395 /*
 396  * Here we use ext4_map_blocks() to get a block mapping for a extent-based
 397  * file rather than ext4_ext_walk_space() because we can introduce
 398  * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same
 399  * function.  When extent status tree has been fully implemented, it will
 400  * track all extent status for a file and we can directly use it to
 401  * retrieve the offset for SEEK_DATA/SEEK_HOLE.
 402  */
 403
 404 /*
 405  * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to
 406  * lookup page cache to check whether or not there has some data between
 407  * [startoff, endoff] because, if this range contains an unwritten extent,
 408  * we determine this extent as a data or a hole according to whether the
 409  * page cache has data or not.
 410  */
 411 static int ext4_find_unwritten_pgoff(struct inode *inode,
 412                                      int whence,
 413                                      ext4_lblk_t end_blk,
 414                                      loff_t *offset)
 415 {
 416         struct pagevec pvec;
 417         unsigned int blkbits;
 418         pgoff_t index;
 419         pgoff_t end;
 420         loff_t endoff;
 421         loff_t startoff;
 422         loff_t lastoff;
 423         int found = 0;
 424
 425         blkbits = inode->i_sb->s_blocksize_bits;
 426         startoff = *offset;
 427         lastoff = startoff;
 428         endoff = (loff_t)end_blk << blkbits;
 429
 430         index = startoff >> PAGE_SHIFT;
 431         end = endoff >> PAGE_SHIFT;
 432
 433         pagevec_init(&pvec, 0);
 434         do {
 435                 int i, num;
 436                 unsigned long nr_pages;
 437
 438                 num = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
 439                 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
 440                                           (pgoff_t)num);
 441                 if (nr_pages == 0) {
 442                         if (whence == SEEK_DATA)
 443                                 break;
 444
 445                         BUG_ON(whence != SEEK_HOLE);
 446                         /*
 447                          * If this is the first time to go into the loop and
 448                          * offset is not beyond the end offset, it will be a
 449                          * hole at this offset
 450                          */
 451                         if (lastoff == startoff || lastoff < endoff)
 452                                 found = 1;
 453                         break;
 454                 }
 455
 456                 /*
 457                  * If this is the first time to go into the loop and
 458                  * offset is smaller than the first page offset, it will be a
 459                  * hole at this offset.
 460                  */
 461                 if (lastoff == startoff && whence == SEEK_HOLE &&
 462                     lastoff < page_offset(pvec.pages[0])) {
 463                         found = 1;
 464                         break;
 465                 }
 466
 467                 for (i = 0; i < nr_pages; i++) {
 468                         struct page *page = pvec.pages[i];
 469                         struct buffer_head *bh, *head;
 470
 471                         /*
 472                          * If the current offset is not beyond the end of given
 473                          * range, it will be a hole.
 474                          */
 475                         if (lastoff < endoff && whence == SEEK_HOLE &&
 476                             page->index > end) {
 477                                 found = 1;
 478                                 *offset = lastoff;
 479                                 goto out;
 480                         }
 481
 482                         lock_page(page);
 483
 484                         if (unlikely(page->mapping != inode->i_mapping)) {
 485                                 unlock_page(page);
 486                                 continue;
 487                         }
 488
 489                         if (!page_has_buffers(page)) {
 490                                 unlock_page(page);
 491                                 continue;
 492                         }
 493
 494                         if (page_has_buffers(page)) {
 495                                 lastoff = page_offset(page);
 496                                 bh = head = page_buffers(page);
 497                                 do {
 498                                         if (buffer_uptodate(bh) ||
 499                                             buffer_unwritten(bh)) {
 500                                                 if (whence == SEEK_DATA)
 501                                                         found = 1;
 502                                         } else {
 503                                                 if (whence == SEEK_HOLE)
 504                                                         found = 1;
 505                                         }
 506                                         if (found) {
 507                                                 *offset = max_t(loff_t,
 508                                                         startoff, lastoff);
 509                                                 unlock_page(page);
 510                                                 goto out;
 511                                         }
 512                                         lastoff += bh->b_size;
 513                                         bh = bh->b_this_page;
 514                                 } while (bh != head);
 515                         }
 516
 517                         lastoff = page_offset(page) + PAGE_SIZE;
 518                         unlock_page(page);
 519                 }
 520
 521                 /*
 522                  * The no. of pages is less than our desired, that would be a
 523                  * hole in there.
 524                  */
 525                 if (nr_pages < num && whence == SEEK_HOLE) {
 526                         found = 1;
 527                         *offset = lastoff;
 528                         break;
 529                 }
 530
 531                 index = pvec.pages[i - 1]->index + 1;
 532                 pagevec_release(&pvec);
 533         } while (index <= end);
 534
 535 out:
 536         pagevec_release(&pvec);
 537         return found;
 538 }
 539
 540 /*
 541  * ext4_seek_data() retrieves the offset for SEEK_DATA.
 542  */
 543 static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
 544 {
 545         struct inode *inode = file->f_mapping->host;
 546         struct extent_status es;
 547         ext4_lblk_t start, last, end;
 548         loff_t dataoff, isize;
 549         int blkbits;
 550         int ret;
 551
 552         inode_lock(inode);
 553
 554         isize = i_size_read(inode);
 555         if (offset >= isize) {
 556                 inode_unlock(inode);
 557                 return -ENXIO;
 558         }
 559
 560         blkbits = inode->i_sb->s_blocksize_bits;
 561         start = offset >> blkbits;
 562         last = start;
 563         end = isize >> blkbits;
 564         dataoff = offset;
 565
 566         do {
 567                 ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
 568                 if (ret <= 0) {
 569                         /* No extent found -> no data */
 570                         if (ret == 0)
 571                                 ret = -ENXIO;
 572                         inode_unlock(inode);
 573                         return ret;
 574                 }
 575
 576                 last = es.es_lblk;
 577                 if (last != start)
 578                         dataoff = (loff_t)last << blkbits;
 579                 if (!ext4_es_is_unwritten(&es))
 580                         break;
 581
 582                 /*
 583                  * If there is a unwritten extent at this offset,
 584                  * it will be as a data or a hole according to page
 585                  * cache that has data or not.
 586                  */
 587                 if (ext4_find_unwritten_pgoff(inode, SEEK_DATA,
 588                                               es.es_lblk + es.es_len, &dataoff))
 589                         break;
 590                 last += es.es_len;
 591                 dataoff = (loff_t)last << blkbits;
 592                 cond_resched();
 593         } while (last <= end);
 594
 595         inode_unlock(inode);
 596
 597         if (dataoff > isize)
 598                 return -ENXIO;
 599
 600         return vfs_setpos(file, dataoff, maxsize);
 601 }
 602
 603 /*
 604  * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
 605  */
 606 static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
 607 {
 608         struct inode *inode = file->f_mapping->host;
 609         struct extent_status es;
 610         ext4_lblk_t start, last, end;
 611         loff_t holeoff, isize;
 612         int blkbits;
 613         int ret;
 614
 615         inode_lock(inode);
 616
 617         isize = i_size_read(inode);
 618         if (offset >= isize) {
 619                 inode_unlock(inode);
 620                 return -ENXIO;
 621         }
 622
 623         blkbits = inode->i_sb->s_blocksize_bits;
 624         start = offset >> blkbits;
 625         last = start;
 626         end = isize >> blkbits;
 627         holeoff = offset;
 628
 629         do {
 630                 ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
 631                 if (ret < 0) {
 632                         inode_unlock(inode);
 633                         return ret;
 634                 }
 635                 /* Found a hole? */
 636                 if (ret == 0 || es.es_lblk > last) {
 637                         if (last != start)
 638                                 holeoff = (loff_t)last << blkbits;
 639                         break;
 640                 }
 641                 /*
 642                  * If there is a unwritten extent at this offset,
 643                  * it will be as a data or a hole according to page
 644                  * cache that has data or not.
 645                  */
 646                 if (ext4_es_is_unwritten(&es) &&
 647                     ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
 648                                               last + es.es_len, &holeoff))
 649                         break;
 650
 651                 last += es.es_len;
 652                 holeoff = (loff_t)last << blkbits;
 653                 cond_resched();
 654         } while (last <= end);
 655
 656         inode_unlock(inode);
 657
 658         if (holeoff > isize)
 659                 holeoff = isize;
 660
 661         return vfs_setpos(file, holeoff, maxsize);
 662 }
 663
 664 /*
 665  * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
 666  * by calling generic_file_llseek_size() with the appropriate maxbytes
 667  * value for each.
 668  */
 669 loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
 670 {
 671         struct inode *inode = file->f_mapping->host;
 672         loff_t maxbytes;
 673
 674         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
 675                 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
 676         else
 677                 maxbytes = inode->i_sb->s_maxbytes;
 678
 679         switch (whence) {
 680         case SEEK_SET:
 681         case SEEK_CUR:
 682         case SEEK_END:
 683                 return generic_file_llseek_size(file, offset, whence,
 684                                                 maxbytes, i_size_read(inode));
 685         case SEEK_DATA:
 686                 return ext4_seek_data(file, offset, maxbytes);
 687         case SEEK_HOLE:
 688                 return ext4_seek_hole(file, offset, maxbytes);
 689         }
 690
 691         return -EINVAL;
 692 }
 693
 694 const struct file_operations ext4_file_operations = {
 695         .llseek         = ext4_llseek,
 696         .read_iter      = generic_file_read_iter,
 697         .write_iter     = ext4_file_write_iter,
 698         .unlocked_ioctl = ext4_ioctl,
 699 #ifdef CONFIG_COMPAT
 700         .compat_ioctl   = ext4_compat_ioctl,
 701 #endif
 702         .mmap           = ext4_file_mmap,
 703         .open           = ext4_file_open,
 704         .release        = ext4_release_file,
 705         .fsync          = ext4_sync_file,
 706         .splice_read    = generic_file_splice_read,
 707         .splice_write   = iter_file_splice_write,
 708         .fallocate      = ext4_fallocate,
 709 };
 710
 711 const struct inode_operations ext4_file_inode_operations = {
 712         .setattr        = ext4_setattr,
 713         .getattr        = ext4_getattr,
 714         .setxattr       = generic_setxattr,
 715         .getxattr       = generic_getxattr,
 716         .listxattr      = ext4_listxattr,
 717         .removexattr    = generic_removexattr,
 718         .get_acl        = ext4_get_acl,
 719         .set_acl        = ext4_set_acl,
 720         .fiemap         = ext4_fiemap,
 721 };
 722