Whoever wrote this was braindead. Also it doesn''t work right if you
have
VACANCY''s since we assumed you would only have that at the end of the
file,
which won''t be the case in the near future. I tested this with
generic/285 and
generic/286 as well as the btrfs tests that use fssum since it uses
seek_hole/seek_data to verify things are ok. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---
fs/btrfs/file.c | 93 +++++++++++++--------------------------------------------
1 file changed, 20 insertions(+), 73 deletions(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index d12107e..728f56f 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 +2427,38 @@ 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);
+ if (whence == SEEK_HOLE &&
+ (em->block_start == EXTENT_MAP_HOLE ||
+ test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
+ break;
+ } else if (whence == SEEK_DATA) {
+ if (em->block_start < EXTENT_MAP_LAST_BYTE &&
+ !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+ break;
+ if (em->block_start == EXTENT_MAP_DELALLOC)
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;
- }
- }
}
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;
--
1.8.3.1
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs"
in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Roman Mamedov
2013-Oct-18 16:11 UTC
Re: [PATCH] Btrfs: fix up seek_hole/seek_data handling
On Fri, 18 Oct 2013 11:48:21 -0400 Josef Bacik <jbacik@fusionio.com> wrote:> Whoever wrote this was braindead.You do realize you sent a number of people googling for "Delalloc is such a pain. If we have a hole and we have pending" just out of curiosity? :)) -- With respect, Roman
On Fri, Oct 18, 2013 at 10:11:15PM +0600, Roman Mamedov wrote:> On Fri, 18 Oct 2013 11:48:21 -0400 > Josef Bacik <jbacik@fusionio.com> wrote: > > > Whoever wrote this was braindead. > > You do realize you sent a number of people googling for "Delalloc is such a > pain. If we have a hole and we have pending" just out of curiosity? :)) >When I say things like this you can just assume it was me who wrote it ;). Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Oct 18, 2013 at 10:11:15PM +0600, Roman Mamedov wrote:> On Fri, 18 Oct 2013 11:48:21 -0400 > Josef Bacik <jbacik@fusionio.com> wrote: > > > Whoever wrote this was braindead. > > You do realize you sent a number of people googling for "Delalloc is such a > pain. If we have a hole and we have pending" just out of curiosity? :))Hmm? git blame, friend :). Not that we needed to. We knew exactly who he was referring to the moment we read the comment. We love us some Josef. - z -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html