* [PATCH] xfs: Fix leak of discard bio
@ 2017-08-02 8:37 Jan Kara
2017-08-02 11:33 ` Dave Chinner
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Jan Kara @ 2017-08-02 8:37 UTC (permalink / raw)
To: linux-xfs; +Cc: Christoph Hellwig, Darrick J . Wong, Jan Kara, stable
The bio describing discard operation is allocated by
__blkdev_issue_discard() which returns us a reference to it. That
reference is never released and thus we leak this bio. Drop the bio
reference once it completes in xlog_discard_endio().
CC: stable@vger.kernel.org
Fixes: 4560e78f40cb55bd2ea8f1ef4001c5baa88531c7
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/xfs/xfs_log_cil.c | 1 +
1 file changed, 1 insertion(+)
Note, this is untested. It's just something I've noticed when looking at the
code.
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index fbe72b134bef..43aa42a3a5d3 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -539,6 +539,7 @@ xlog_discard_endio(
INIT_WORK(&ctx->discard_endio_work, xlog_discard_endio_work);
queue_work(xfs_discard_wq, &ctx->discard_endio_work);
+ bio_put(bio);
}
static void
--
2.12.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] xfs: Fix leak of discard bio
2017-08-02 8:37 [PATCH] xfs: Fix leak of discard bio Jan Kara
@ 2017-08-02 11:33 ` Dave Chinner
2017-08-02 13:17 ` Jan Kara
2017-08-02 19:37 ` Darrick J. Wong
2017-08-05 13:56 ` Christoph Hellwig
2 siblings, 1 reply; 5+ messages in thread
From: Dave Chinner @ 2017-08-02 11:33 UTC (permalink / raw)
To: Jan Kara; +Cc: linux-xfs, Christoph Hellwig, Darrick J . Wong, stable
On Wed, Aug 02, 2017 at 10:37:41AM +0200, Jan Kara wrote:
> The bio describing discard operation is allocated by
> __blkdev_issue_discard() which returns us a reference to it. That
> reference is never released and thus we leak this bio. Drop the bio
> reference once it completes in xlog_discard_endio().
>
> CC: stable@vger.kernel.org
> Fixes: 4560e78f40cb55bd2ea8f1ef4001c5baa88531c7
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
> fs/xfs/xfs_log_cil.c | 1 +
> 1 file changed, 1 insertion(+)
>
> Note, this is untested. It's just something I've noticed when looking at the
> code.
>
> diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
> index fbe72b134bef..43aa42a3a5d3 100644
> --- a/fs/xfs/xfs_log_cil.c
> +++ b/fs/xfs/xfs_log_cil.c
> @@ -539,6 +539,7 @@ xlog_discard_endio(
>
> INIT_WORK(&ctx->discard_endio_work, xlog_discard_endio_work);
> queue_work(xfs_discard_wq, &ctx->discard_endio_work);
> + bio_put(bio);
> }
At a quick glance, it does seem that we are leaking the bio here. It
appears to me that ext4_process_freed_data() also has the same
problem and leaks the discard_bio....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] xfs: Fix leak of discard bio
2017-08-02 11:33 ` Dave Chinner
@ 2017-08-02 13:17 ` Jan Kara
0 siblings, 0 replies; 5+ messages in thread
From: Jan Kara @ 2017-08-02 13:17 UTC (permalink / raw)
To: Dave Chinner
Cc: Jan Kara, linux-xfs, Christoph Hellwig, Darrick J . Wong, stable
On Wed 02-08-17 21:33:49, Dave Chinner wrote:
> On Wed, Aug 02, 2017 at 10:37:41AM +0200, Jan Kara wrote:
> > The bio describing discard operation is allocated by
> > __blkdev_issue_discard() which returns us a reference to it. That
> > reference is never released and thus we leak this bio. Drop the bio
> > reference once it completes in xlog_discard_endio().
> >
> > CC: stable@vger.kernel.org
> > Fixes: 4560e78f40cb55bd2ea8f1ef4001c5baa88531c7
> > Signed-off-by: Jan Kara <jack@suse.cz>
> > ---
> > fs/xfs/xfs_log_cil.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > Note, this is untested. It's just something I've noticed when looking at the
> > code.
> >
> > diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
> > index fbe72b134bef..43aa42a3a5d3 100644
> > --- a/fs/xfs/xfs_log_cil.c
> > +++ b/fs/xfs/xfs_log_cil.c
> > @@ -539,6 +539,7 @@ xlog_discard_endio(
> >
> > INIT_WORK(&ctx->discard_endio_work, xlog_discard_endio_work);
> > queue_work(xfs_discard_wq, &ctx->discard_endio_work);
> > + bio_put(bio);
> > }
>
> At a quick glance, it does seem that we are leaking the bio here. It
> appears to me that ext4_process_freed_data() also has the same
> problem and leaks the discard_bio....
Yes, and a fix of that prompted me to look into how XFS does things ;)
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] xfs: Fix leak of discard bio
2017-08-02 8:37 [PATCH] xfs: Fix leak of discard bio Jan Kara
2017-08-02 11:33 ` Dave Chinner
@ 2017-08-02 19:37 ` Darrick J. Wong
2017-08-05 13:56 ` Christoph Hellwig
2 siblings, 0 replies; 5+ messages in thread
From: Darrick J. Wong @ 2017-08-02 19:37 UTC (permalink / raw)
To: Jan Kara; +Cc: linux-xfs, Christoph Hellwig, stable
On Wed, Aug 02, 2017 at 10:37:41AM +0200, Jan Kara wrote:
> The bio describing discard operation is allocated by
> __blkdev_issue_discard() which returns us a reference to it. That
> reference is never released and thus we leak this bio. Drop the bio
> reference once it completes in xlog_discard_endio().
>
> CC: stable@vger.kernel.org
> Fixes: 4560e78f40cb55bd2ea8f1ef4001c5baa88531c7
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
> fs/xfs/xfs_log_cil.c | 1 +
> 1 file changed, 1 insertion(+)
>
> Note, this is untested. It's just something I've noticed when looking at the
> code.
>
> diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
> index fbe72b134bef..43aa42a3a5d3 100644
> --- a/fs/xfs/xfs_log_cil.c
> +++ b/fs/xfs/xfs_log_cil.c
> @@ -539,6 +539,7 @@ xlog_discard_endio(
>
> INIT_WORK(&ctx->discard_endio_work, xlog_discard_endio_work);
> queue_work(xfs_discard_wq, &ctx->discard_endio_work);
> + bio_put(bio);
It would seem that we /do/ leak the bio here. :(
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
--D
> }
>
> static void
> --
> 2.12.3
>
> --
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] xfs: Fix leak of discard bio
2017-08-02 8:37 [PATCH] xfs: Fix leak of discard bio Jan Kara
2017-08-02 11:33 ` Dave Chinner
2017-08-02 19:37 ` Darrick J. Wong
@ 2017-08-05 13:56 ` Christoph Hellwig
2 siblings, 0 replies; 5+ messages in thread
From: Christoph Hellwig @ 2017-08-05 13:56 UTC (permalink / raw)
To: Jan Kara; +Cc: linux-xfs, Christoph Hellwig, Darrick J . Wong, stable
Looks fine,
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-08-02 8:37 [PATCH] xfs: Fix leak of discard bio Jan Kara
2017-08-02 11:33 ` Dave Chinner
2017-08-02 13:17 ` Jan Kara
2017-08-02 19:37 ` Darrick J. Wong
2017-08-05 13:56 ` Christoph Hellwig
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