From 6eca9004dfcb274a502438a591df5b197690afb1 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 25 Oct 2007 10:14:47 +0200 Subject: [BLOCK] Fix bad sharing of tag busy list on queues with shared tag maps For the locking to work, only the tag map and tag bit map may be shared (incidentally, I was just explaining this to Nick yesterday, but I apparently didn't review the code well enough myself). But we also share the busy list! The busy_list must be queue private, or we need a block_queue_tag covering lock as well. So we have to move the busy_list to the queue. This'll work fine, and it'll actually also fix a problem with blk_queue_invalidate_tags() which will invalidate tags across all shared queues. This is a bit confusing, the low level driver should call it for each queue seperately since otherwise you cannot kill tags on just a single queue for eg a hard drive that stops responding. Since the function has no callers currently, it's not an issue. Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index bbf906a0b419..8396db24d019 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -341,7 +341,6 @@ 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 */ - struct list_head busy_list; /* fifo list of busy tags */ int busy; /* current depth */ int max_depth; /* what we will send to device */ int real_max_depth; /* what the array can hold */ @@ -435,6 +434,7 @@ struct request_queue unsigned int dma_alignment; struct blk_queue_tag *queue_tags; + struct list_head tag_busy_list; unsigned int nr_sorted; unsigned int in_flight; -- cgit v1.2.3