xfs: fortify xfs_alloc_buftarg error handling (d210a987) · Commits · 戴 / test

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>

fs/xfs/xfs_buf.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -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;
		}

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