ocfs2: fix a misuse a of brelse after failing ocfs2_check_dir_entry
diff mbox

Message ID HK2PR06MB04522E81177A3E01EF47A828D56F0@HK2PR06MB0452.apcprd06.prod.outlook.com
State New
Headers show

Commit Message

Changwei Ge May 27, 2018, 3:16 a.m. UTC
From: Changwei Ge <ge.changwei@h3c.com>

Somehow, file system metadata was corrupted, which causes
ocfs2_check_dir_entry() to fail in function ocfs2_dir_foreach_blk_el().

According to the original design intention, if above happens we should
skip the problematic block and continue to retrieve dir entry. But there
is obviouse misuse of brelse around related code.

After failure of ocfs2_check_dir_entry(), currunt code just moves to next
position and uses the problematic buffer head again and again during
which the problematic buffer head is released for multiple times. I
suppose, this a serious issue which is long-lived in ocfs2. This may
cause other file systems which is also used in a the same host insane.

So we should also consider about bakcporting this patch into
linux -stable.

Suggested-by: Changkuo Shi <shi.changkuo@h3c.com>
Signed-off-by: Changwei Ge <ge.changwei@h3c.com>
---
 fs/ocfs2/dir.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Greg KH May 27, 2018, 5:42 a.m. UTC | #1
On Sun, May 27, 2018 at 03:16:52AM +0000, Changwei Ge wrote:
> From: Changwei Ge <ge.changwei@h3c.com>
> 
> Somehow, file system metadata was corrupted, which causes
> ocfs2_check_dir_entry() to fail in function ocfs2_dir_foreach_blk_el().
> 
> According to the original design intention, if above happens we should
> skip the problematic block and continue to retrieve dir entry. But there
> is obviouse misuse of brelse around related code.
> 
> After failure of ocfs2_check_dir_entry(), currunt code just moves to next
> position and uses the problematic buffer head again and again during
> which the problematic buffer head is released for multiple times. I
> suppose, this a serious issue which is long-lived in ocfs2. This may
> cause other file systems which is also used in a the same host insane.
> 
> So we should also consider about bakcporting this patch into
> linux -stable.
> 
> Suggested-by: Changkuo Shi <shi.changkuo@h3c.com>
> Signed-off-by: Changwei Ge <ge.changwei@h3c.com>
> ---
>  fs/ocfs2/dir.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://urldefense.proofpoint.com/v2/url?u=https-3A__www.kernel.org_doc_html_latest_process_stable-2Dkernel-2Drules.html&d=DwIBAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=C7gAd4uDxlAvTdc0vmU6X8CMk6L2iDY8-HD0qT6Fo7Y&m=ZFGNdxMGJOFwcOvw1WPDqEeWXHqRt00lPWocekbXDwg&s=bqQ638ETryFkKttOq4dXSro7DV0OgJy7WTajPiK6fxw&e=
for how to do this properly.

</formletter>

Patch
diff mbox

diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index b048d4f..c121abb 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -1897,8 +1897,7 @@  static int ocfs2_dir_foreach_blk_el(struct inode *inode,
 				/* On error, skip the f_pos to the
 				   next block. */
 				ctx->pos = (ctx->pos | (sb->s_blocksize - 1)) + 1;
-				brelse(bh);
-				continue;
+				break;
 			}
 			if (le64_to_cpu(de->inode)) {
 				unsigned char d_type = DT_UNKNOWN;