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authorMing Lei <ming.lei@redhat.com>2018-08-02 13:23:26 +0300
committerJens Axboe <axboe@kernel.dk>2018-08-02 23:41:58 +0300
commit75d6e175fc511e95ae3eb8f708680133bc211ed3 (patch)
tree8a0a8ef6c94333a8d42e76b123d8fadc82af4c35
parentb233f127042dba991229e3882c6217c80492f6ef (diff)
downloadlinux-75d6e175fc511e95ae3eb8f708680133bc211ed3.tar.xz
blk-mq: fix updating tags depth
The passed 'nr' from userspace represents the total depth, meantime inside 'struct blk_mq_tags', 'nr_tags' stores the total tag depth, and 'nr_reserved_tags' stores the reserved part. There are two issues in blk_mq_tag_update_depth() now: 1) for growing tags, we should have used the passed 'nr', and keep the number of reserved tags not changed. 2) the passed 'nr' should have been used for checking against 'tags->nr_tags', instead of number of the normal part. This patch fixes the above two cases, and avoids kernel crash caused by wrong resizing sbitmap queue. Cc: "Ewan D. Milne" <emilne@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Omar Sandoval <osandov@fb.com> Tested by: Marco Patalano <mpatalan@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-mq-tag.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 09b2ee6694fb..c43b3398d7b4 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -399,8 +399,6 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
if (tdepth <= tags->nr_reserved_tags)
return -EINVAL;
- tdepth -= tags->nr_reserved_tags;
-
/*
* If we are allowed to grow beyond the original size, allocate
* a new set of tags before freeing the old one.
@@ -420,7 +418,8 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
if (tdepth > 16 * BLKDEV_MAX_RQ)
return -EINVAL;
- new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, 0);
+ new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth,
+ tags->nr_reserved_tags);
if (!new)
return -ENOMEM;
ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth);
@@ -437,7 +436,8 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
* Don't need (or can't) update reserved tags here, they
* remain static and should never need resizing.
*/
- sbitmap_queue_resize(&tags->bitmap_tags, tdepth);
+ sbitmap_queue_resize(&tags->bitmap_tags,
+ tdepth - tags->nr_reserved_tags);
}
return 0;