xfs: fortify xfs_alloc_buftarg error handling

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 <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Michal Hocko 2017-11-23 17:13:40 +01:00 committed by Darrick J. Wong
parent 509955823c
commit d210a9874b

View File

@ -1815,22 +1815,27 @@ 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;
}