blk-tag: Use atomic_t type for bqt->busy. bqt->busy is an integer that keeps count of number of outstanding tags. For host-wide shared tag map, busy is accessed in a queue lock (not host lock) which corrupts the busy value. Change busy to atomic_t and use atomic macros to access it. Signed-off-by: Abhijeet Joglekar <abjoglek@xxxxxxxxx> --- block/blk-tag.c | 8 ++++---- include/linux/blkdev.h | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/block/blk-tag.c b/block/blk-tag.c index 32667be..8f37d08 100644 --- a/block/blk-tag.c +++ b/block/blk-tag.c @@ -38,7 +38,7 @@ static int __blk_free_tags(struct blk_queue_tag *bqt) retval = atomic_dec_and_test(&bqt->refcnt); if (retval) { - BUG_ON(bqt->busy); + BUG_ON(atomic_read(&bqt->busy)); kfree(bqt->tag_index); bqt->tag_index = NULL; @@ -147,7 +147,7 @@ static struct blk_queue_tag *__blk_queue_init_tags(struct request_queue *q, if (init_tag_map(q, tags, depth)) goto fail; - tags->busy = 0; + atomic_set(&tags->busy, 0); atomic_set(&tags->refcnt, 1); return tags; fail: @@ -313,7 +313,7 @@ void blk_queue_end_tag(struct request_queue *q, struct request *rq) * unlock memory barrier semantics. */ clear_bit_unlock(tag, bqt->tag_map); - bqt->busy--; + atomic_dec(&bqt->busy); } EXPORT_SYMBOL(blk_queue_end_tag); @@ -368,7 +368,7 @@ int blk_queue_start_tag(struct request_queue *q, struct request *rq) bqt->tag_index[tag] = rq; blkdev_dequeue_request(rq); list_add(&rq->queuelist, &q->tag_busy_list); - bqt->busy++; + atomic_inc(&bqt->busy); return 0; } EXPORT_SYMBOL(blk_queue_start_tag); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 88d6808..106531e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -274,7 +274,7 @@ enum blk_queue_state { struct blk_queue_tag { struct request **tag_index; /* map of busy tags */ unsigned long *tag_map; /* bit map of free/busy tags */ - int busy; /* current depth */ + atomic_t busy; /* current depth */ int max_depth; /* what we will send to device */ int real_max_depth; /* what the array can hold */ atomic_t refcnt; /* map can be shared */ -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html