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btrfs: use folio_contains() for EOF detection

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Currently we use the following pattern to detect if the folio contains
the end of a file:

	if (folio->index == end_index)
		folio_zero_range();

But that only works if the folio is page sized.

For the following case, it will not work and leave the range beyond EOF
uninitialized:

  The page size is 4K, and the fs block size is also 4K.

	16K        20K       24K
        |          |     |   |
	                 |
                         EOF at 22K

And we have a large folio sized 8K at file offset 16K.

In that case, the old "folio->index == end_index" will not work, thus
the range [22K, 24K) will not be zeroed out.

Fix the following call sites which use the above pattern:

- add_ra_bio_pages()

- extent_writepage()

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo
2025-05-15 14:30:43 +02:00
committed by David Sterba
parent e1fcad644b
commit 2b14b74b99
2 changed files with 4 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/btrfs/compression.c
+1 -1
View File
@@ -523,7 +523,7 @@ static noinline int add_ra_bio_pages(struct inode *inode,
free_extent_map(em);
unlock_extent(tree, cur, page_end, NULL);
if (folio->index == end_index) {
if (folio_contains(folio, end_index)) {
size_t zero_offset = offset_in_folio(folio, isize);
if (zero_offset) {
fs/btrfs/extent_io.c
+3 -3
View File
@@ -221,7 +221,7 @@ static void __process_folios_contig(struct address_space *mapping,
}
static noinline void unlock_delalloc_folio(const struct inode *inode,
const struct folio *locked_folio,
struct folio *locked_folio,
u64 start, u64 end)
{
ASSERT(locked_folio);
@@ -231,7 +231,7 @@ static noinline void unlock_delalloc_folio(const struct inode *inode,
}
static noinline int lock_delalloc_folios(struct inode *inode,
const struct folio *locked_folio,
struct folio *locked_folio,
u64 start, u64 end)
{
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
@@ -1707,7 +1707,7 @@ static int extent_writepage(struct folio *folio, struct btrfs_bio_ctrl *bio_ctrl
return 0;
}
if (folio->index == end_index)
if (folio_contains(folio, end_index))
folio_zero_range(folio, pg_offset, folio_size(folio) - pg_offset);
/*