4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michal Hocko <[email protected]>


[ Upstream commit d210a9874b8f6166579408131cb74495caff1958 ]

percpu_counter_init failure path doesn't clean up &btp->bt_lru list.
Call list_lru_destroy in that error path. Similarly register_shrinker
error path is not handled.

While it is unlikely to trigger these error path, it is not impossible
especially the later might fail with large NUMAs.  Let's handle the
failure to make the code more robust.

Noticed-by: Tetsuo Handa <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Dave Chinner <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 fs/xfs/xfs_buf.c |   15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1813,22 +1813,27 @@ xfs_alloc_buftarg(
        btp->bt_daxdev = dax_dev;
 
        if (xfs_setsize_buftarg_early(btp, bdev))
-               goto error;
+               goto error_free;
 
        if (list_lru_init(&btp->bt_lru))
-               goto error;
+               goto error_free;
 
        if (percpu_counter_init(&btp->bt_io_count, 0, GFP_KERNEL))
-               goto error;
+               goto error_lru;
 
        btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count;
        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))
+               goto error_pcpu;
        return btp;
 
-error:
+error_pcpu:
+       percpu_counter_destroy(&btp->bt_io_count);
+error_lru:
+       list_lru_destroy(&btp->bt_lru);
+error_free:
        kmem_free(btp);
        return NULL;
 }


Reply via email to