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-rw-r--r--fs/btrfs/file.c94
1 files changed, 19 insertions, 75 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 72da4df53c9a..bf3465cf455a 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2405,14 +2405,12 @@ out_reserve_fail:
static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
- struct extent_map *em;
+ struct extent_map *em = NULL;
struct extent_state *cached_state = NULL;
u64 lockstart = *offset;
u64 lockend = i_size_read(inode);
u64 start = *offset;
- u64 orig_start = *offset;
u64 len = i_size_read(inode);
- u64 last_end = 0;
int ret = 0;
lockend = max_t(u64, root->sectorsize, lockend);
@@ -2429,89 +2427,35 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
&cached_state);
- /*
- * Delalloc is such a pain. If we have a hole and we have pending
- * delalloc for a portion of the hole we will get back a hole that
- * exists for the entire range since it hasn't been actually written
- * yet. So to take care of this case we need to look for an extent just
- * before the position we want in case there is outstanding delalloc
- * going on here.
- */
- if (whence == SEEK_HOLE && start != 0) {
- if (start <= root->sectorsize)
- em = btrfs_get_extent_fiemap(inode, NULL, 0, 0,
- root->sectorsize, 0);
- else
- em = btrfs_get_extent_fiemap(inode, NULL, 0,
- start - root->sectorsize,
- root->sectorsize, 0);
- if (IS_ERR(em)) {
- ret = PTR_ERR(em);
- goto out;
- }
- last_end = em->start + em->len;
- if (em->block_start == EXTENT_MAP_DELALLOC)
- last_end = min_t(u64, last_end, inode->i_size);
- free_extent_map(em);
- }
-
- while (1) {
+ while (start < inode->i_size) {
em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
+ em = NULL;
break;
}
- if (em->block_start == EXTENT_MAP_HOLE) {
- if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
- if (last_end <= orig_start) {
- free_extent_map(em);
- ret = -ENXIO;
- break;
- }
- }
-
- if (whence == SEEK_HOLE) {
- *offset = start;
- free_extent_map(em);
- break;
- }
- } else {
- if (whence == SEEK_DATA) {
- if (em->block_start == EXTENT_MAP_DELALLOC) {
- if (start >= inode->i_size) {
- free_extent_map(em);
- ret = -ENXIO;
- break;
- }
- }
-
- if (!test_bit(EXTENT_FLAG_PREALLOC,
- &em->flags)) {
- *offset = start;
- free_extent_map(em);
- break;
- }
- }
- }
+ if (whence == SEEK_HOLE &&
+ (em->block_start == EXTENT_MAP_HOLE ||
+ test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
+ break;
+ else if (whence == SEEK_DATA &&
+ (em->block_start != EXTENT_MAP_HOLE &&
+ !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
+ break;
start = em->start + em->len;
- last_end = em->start + em->len;
-
- if (em->block_start == EXTENT_MAP_DELALLOC)
- last_end = min_t(u64, last_end, inode->i_size);
-
- if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
- free_extent_map(em);
- ret = -ENXIO;
- break;
- }
free_extent_map(em);
+ em = NULL;
cond_resched();
}
- if (!ret)
- *offset = min(*offset, inode->i_size);
-out:
+ free_extent_map(em);
+ if (!ret) {
+ if (whence == SEEK_DATA && start >= inode->i_size)
+ ret = -ENXIO;
+ else
+ *offset = min_t(loff_t, start, inode->i_size);
+ }
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
&cached_state, GFP_NOFS);
return ret;