Commit 5676e7b6 authored Sep 02, 2014 by Robert Elliott Committed by Jens Axboe Sep 03, 2014

blk-mq: cleanup after blk_mq_init_rq_map failures



In blk-mq.c blk_mq_alloc_tag_set, if:
	set->tags = kmalloc_node()
succeeds, but one of the blk_mq_init_rq_map() calls fails,
	goto out_unwind;
needs to free set->tags so the caller is not obligated
to do so.  None of the current callers (null_blk,
virtio_blk, virtio_blk, or the forthcoming scsi-mq)
do so.

set->tags needs to be set to NULL after doing so,
so other tag cleanup logic doesn't try to free
a stale pointer later.  Also set it to NULL
in blk_mq_free_tag_set.

Tested with error injection on the forthcoming
scsi-mq + hpsa combination.

Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent dc501dc0

block/blk-mq.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -1982,6 +1982,8 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
		out_unwind:
		while (--i >= 0)
		blk_mq_free_rq_map(set, set->tags[i], i);
		kfree(set->tags);
		set->tags = NULL;
		out:
		return -ENOMEM;
		}
		@@ -1997,6 +1999,7 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
		}

		kfree(set->tags);
		set->tags = NULL;
		}
		EXPORT_SYMBOL(blk_mq_free_tag_set);

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