diff mbox

xfs: handle register_shrinker error

Message ID 20171123120828.31881-1-mhocko@kernel.org (mailing list archive)
State Superseded
Headers show

Commit Message

Michal Hocko Nov. 23, 2017, 12:08 p.m. UTC 
From: Michal Hocko <mhocko@suse.com>

xfs_alloc_buftarg doesn't handle register_shrinker error path. While it
is unlikely to trigger it is not impossible especially with large NUMAs.
Let's handle the failure to make the code more robust.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---

Hi,
this is not tested but it looks quite straightforward. There is one more
unchecked register_shrinker in xfs_qm_init_quotainfo but my absolute
lack of familiarity with the code didn't allow me to come up with a
mechanical fix like this one.

 fs/xfs/xfs_buf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Christoph Hellwig Nov. 23, 2017, 1:26 p.m. UTC | #1 
Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

I can take a stab at the quota one.
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Michal Hocko Nov. 23, 2017, 1:41 p.m. UTC | #2 
On Thu 23-11-17 05:26:33, Christoph Hellwig wrote:
> Looks good,
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Thanks!

> I can take a stab at the quota one.

That would be really great!
Tetsuo Handa Nov. 23, 2017, 4:01 p.m. UTC | #3 
Michal Hocko wrote:
> On Thu 23-11-17 05:26:33, Christoph Hellwig wrote:
> > Looks good,
> > 
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> 
> Thanks!
> 
> > I can take a stab at the quota one.
> 
> That would be really great!
> 
Again, it does not look good. Since kmem_free() does only kvfree(),
nothing will release memory allocated by list_lru_init().
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diff mbox

Patch

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 4db6e8d780f6..dd0e18af990c 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1827,7 +1827,10 @@  xfs_alloc_buftarg(
 	btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan;
 	btp->bt_shrinker.seeks = DEFAULT_SEEKS;
 	btp->bt_shrinker.flags = SHRINKER_NUMA_AWARE;
-	register_shrinker(&btp->bt_shrinker);
+	if (register_shrinker(&btp->bt_shrinker)) {
+		percpu_counter_destroy(&btp->bt_io_count);
+		goto error;
+	}
 	return btp;
 
 error: