[PATCH V15 03/15] Btrfs: subpage-blocksize: Make sure delalloc range intersects with the locked page's range
From: Chandan Rajendra <hidden>
Date: 2016-02-11 17:49:07
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
find_delalloc_range indirectly depends on EXTENT_UPTODDATE to make sure that the delalloc range returned intersects with the file range mapped by the page. Since we now track "uptodate" state in a per-page bitmap (i.e. in btrfs_page_private->bstate), this commit makes an explicit check to make sure that the delalloc range starts from within the file range mapped by the page. Signed-off-by: Chandan Rajendra <redacted> --- fs/btrfs/extent_io.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 3228446..da54e49 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c@@ -1570,6 +1570,7 @@ out: * 1 is returned if we find something, 0 if nothing was in the tree */ static noinline u64 find_delalloc_range(struct extent_io_tree *tree, + struct page *locked_page, u64 *start, u64 *end, u64 max_bytes, struct extent_state **cached_state) {
@@ -1578,6 +1579,9 @@ static noinline u64 find_delalloc_range(struct extent_io_tree *tree, u64 cur_start = *start; u64 found = 0; u64 total_bytes = 0; + u64 page_end; + + page_end = page_offset(locked_page) + PAGE_CACHE_SIZE - 1; spin_lock(&tree->lock);
@@ -1598,7 +1602,8 @@ static noinline u64 find_delalloc_range(struct extent_io_tree *tree, (state->state & EXTENT_BOUNDARY))) { goto out; } - if (!(state->state & EXTENT_DELALLOC)) { + if (!(state->state & EXTENT_DELALLOC) + || (page_end < state->start)) { if (!found) *end = state->end; goto out;
@@ -1736,8 +1741,9 @@ again: /* step one, find a bunch of delalloc bytes starting at start */ delalloc_start = *start; delalloc_end = 0; - found = find_delalloc_range(tree, &delalloc_start, &delalloc_end, - max_bytes, &cached_state); + found = find_delalloc_range(tree, locked_page, + &delalloc_start, &delalloc_end, + max_bytes, &cached_state); if (!found || delalloc_end <= *start) { *start = delalloc_start; *end = delalloc_end;
--
2.1.0