[PATCH 2/2] ext4: Fix off-by-in in loop termination in ext4_find_unwritten_pgoff()
From: Jan Kara <jack@suse.cz>
Date: 2017-05-18 10:49:54
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
There is an off-by-one error in loop termination conditions in ext4_find_unwritten_pgoff() since 'end' may index a page beyond end of desired range if 'endoff' is page aligned. It doesn't have any visible effects but still it is good to fix it. Signed-off-by: Jan Kara <jack@suse.cz> --- fs/ext4/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index bbea2dccd584..2b00bf84c05b 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c@@ -474,7 +474,7 @@ static int ext4_find_unwritten_pgoff(struct inode *inode, endoff = (loff_t)end_blk << blkbits; index = startoff >> PAGE_SHIFT; - end = endoff >> PAGE_SHIFT; + end = (endoff - 1) >> PAGE_SHIFT; pagevec_init(&pvec, 0); do {
--
2.12.0