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authorJens Axboe <axboe@fb.com>2017-04-27 07:45:46 -0600
committerJens Axboe <axboe@fb.com>2017-04-27 07:45:46 -0600
commit339318080b028fe347c279672da63c1cd5e52044 (patch)
treebfab790c1986205cbcdab48e341b379056bf7863 /block
parenta4e84aae8139aca9fbfbced1f45c51ca81b57488 (diff)
downloadop-kernel-dev-339318080b028fe347c279672da63c1cd5e52044.zip
op-kernel-dev-339318080b028fe347c279672da63c1cd5e52044.tar.gz
blk-mq-sched: alloate reserved tags out of normal pool
At least one driver, mtip32xx, has a hard coded dependency on the value of the reserved tag used for internal commands. While that should really be fixed up, for now let's ensure that we just bypass the scheduler tags an allocation marked as reserved. They are used for house keeping or error handling, so we can safely ignore them in the scheduler. Tested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
-rw-r--r--block/blk-mq-sched.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index e79e9f1..8b361e1 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -82,7 +82,11 @@ struct request *blk_mq_sched_get_request(struct request_queue *q,
if (likely(!data->hctx))
data->hctx = blk_mq_map_queue(q, data->ctx->cpu);
- if (e) {
+ /*
+ * For a reserved tag, allocate a normal request since we might
+ * have driver dependencies on the value of the internal tag.
+ */
+ if (e && !(data->flags & BLK_MQ_REQ_RESERVED)) {
data->flags |= BLK_MQ_REQ_INTERNAL;
/*
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