diff mbox

[3/6] Btrfs: fix off-by-one error of the same page check in btrfs_punch_hole()

Message ID 50BF27B9.7030501@cn.fujitsu.com (mailing list archive)
State New, archived
Headers show

Commit Message

Miao Xie Dec. 5, 2012, 10:53 a.m. UTC
(start + len) is the start of the adjacent extent, not the end of the current
extent, so we should not use it to check the hole is on the same page or not.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
 fs/btrfs/file.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
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Patch

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index bd5afcc..b477da2 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1881,8 +1881,8 @@  static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 	unsigned long nr;
 	int ret = 0;
 	int err = 0;
-	bool same_page = (offset >> PAGE_CACHE_SHIFT) ==
-		((offset + len) >> PAGE_CACHE_SHIFT);
+	bool same_page = ((offset >> PAGE_CACHE_SHIFT) ==
+			  ((offset + len - 1) >> PAGE_CACHE_SHIFT));
 
 	btrfs_wait_ordered_range(inode, offset, len);