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author | Christoph Hellwig <hch@lst.de> | 2013-10-28 19:33:58 (GMT) |
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committer | Jens Axboe <axboe@kernel.dk> | 2013-10-28 19:33:58 (GMT) |
commit | 3228f48be2d19b2dd90db96ec16a40187a2946f3 (patch) | |
tree | 2f148dd8e82b287fc7b682cabc5614e3046d8949 /block/blk-core.c | |
parent | 280d45f6c35d8d7a0fe20c36caf426e3ac139cf9 (diff) | |
download | linux-fsl-qoriq-3228f48be2d19b2dd90db96ec16a40187a2946f3.tar.xz |
blk-mq: fix for flush deadlock
The flush state machine takes in a struct request, which then is
submitted multiple times to the underling driver. The old block code
requeses the same request for each of those, so it does not have an
issue with tapping into the request pool. The new one on the other hand
allocates a new request for each of the actualy steps of the flush
sequence. If have already allocated all of the tags for IO, we will
fail allocating the flush request.
Set aside a reserved request just for flushes.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-core.c')
-rw-r--r-- | block/blk-core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 3bb9e9f..9677c65 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1102,7 +1102,7 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw, struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask) { if (q->mq_ops) - return blk_mq_alloc_request(q, rw, gfp_mask); + return blk_mq_alloc_request(q, rw, gfp_mask, false); else return blk_old_get_request(q, rw, gfp_mask); } |