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authorKeith Busch <keith.busch@intel.com>2017-05-30 14:39:11 -0400
committerJens Axboe <axboe@fb.com>2017-05-30 12:32:37 -0600
commite4dc2b32df5573b077f6723e01cf761d236d5113 (patch)
tree33a61d78cffb1db47474a60157d550c55e0ce6a8 /block
parentfa9765323a93473d3853d04c9903958453c92ad4 (diff)
downloadlinux-e4dc2b32df5573b077f6723e01cf761d236d5113.tar.bz2
blk-mq: Take tagset lock when updating hw queues
The tagset lock needs to be held when iterating the tag_list, so a lockdep assert was added when updating number of hardware queues. The drivers calling this API, however, were unaware of the new requirement, so are failing the assertion. This patch takes the lock within the blk-mq function so the drivers do not have to be modified in order to be safe. Fixes: 705cda97e ("blk-mq: Make it safe to use RCU to iterate over blk_mq_tag_set.tag_list") Reported-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
-rw-r--r--block/blk-mq.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index f2224ffd225d..1bcccedcc74f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2641,7 +2641,8 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
return ret;
}
-void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
+static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
+ int nr_hw_queues)
{
struct request_queue *q;
@@ -2665,6 +2666,13 @@ void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
list_for_each_entry(q, &set->tag_list, tag_set_list)
blk_mq_unfreeze_queue(q);
}
+
+void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
+{
+ mutex_lock(&set->tag_list_lock);
+ __blk_mq_update_nr_hw_queues(set, nr_hw_queues);
+ mutex_unlock(&set->tag_list_lock);
+}
EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
/* Enable polling stats and return whether they were already enabled. */