diff mbox

[resend] UBIFS: Add log overlap assertions

Message ID 53D85A81.3010106@huawei.com
State Accepted
Headers show

Commit Message

hujianyang July 30, 2014, 2:37 a.m. UTC
We use a circle area to record the log nodes in ubifs. This log area
should not be overlapped. But after researching the code, I found
some conditions may lead log head wraps log ltail. Although we've
fixed the problems discovered, there may be some other issues still
left.

This patch adds assertions where lhead changes to next leb to make
sure ltail is not wrapped.


Signed-off-by: hujianyang <hujianyang@huawei.com>
---
 fs/ubifs/log.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Artem Bityutskiy July 31, 2014, 12:54 p.m. UTC | #1
On Wed, 2014-07-30 at 10:37 +0800, hujianyang wrote:
> We use a circle area to record the log nodes in ubifs. This log area
> should not be overlapped. But after researching the code, I found
> some conditions may lead log head wraps log ltail. Although we've
> fixed the problems discovered, there may be some other issues still
> left.
> 
> This patch adds assertions where lhead changes to next leb to make
> sure ltail is not wrapped.

Pushed to linux-ubifs.
diff mbox

Patch

diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c
index 7e818ec..c14628f 100644
--- a/fs/ubifs/log.c
+++ b/fs/ubifs/log.c
@@ -244,6 +244,7 @@  int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)

 	if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
 		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+		ubifs_assert(c->lhead_lnum != c->ltail_lnum);
 		c->lhead_offs = 0;
 	}

@@ -408,6 +409,7 @@  int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
 	/* Switch to the next log LEB */
 	if (c->lhead_offs) {
 		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+		ubifs_assert(c->lhead_lnum != c->ltail_lnum);
 		c->lhead_offs = 0;
 	}