diff options
author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-03-09 20:35:53 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-03-09 20:35:53 (GMT) |
commit | 263a5c8e16c34199ddf6de3f102e789ffa3ee26e (patch) | |
tree | 4f049e339d522b2ab0ba3bed3ec217e4bbc83d35 /block/blk-core.c | |
parent | 54d20f006ceff1f2f1e69d0e54049b6c0765c039 (diff) | |
parent | 192cfd58774b4d17b2fe8bdc77d89c2ef4e0591d (diff) | |
download | linux-263a5c8e16c34199ddf6de3f102e789ffa3ee26e.tar.xz |
Merge 3.3-rc6 into driver-core-next
This was done to resolve a conflict in the drivers/base/cpu.c file.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block/blk-core.c')
-rw-r--r-- | block/blk-core.c | 33 |
1 files changed, 17 insertions, 16 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index e6c05a9..3a78b00 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -642,7 +642,7 @@ static inline void blk_free_request(struct request_queue *q, struct request *rq) if (rq->cmd_flags & REQ_ELVPRIV) { elv_put_request(q, rq); if (rq->elv.icq) - put_io_context(rq->elv.icq->ioc, q); + put_io_context(rq->elv.icq->ioc); } mempool_free(rq, q->rq.rq_pool); @@ -872,13 +872,15 @@ retry: spin_unlock_irq(q->queue_lock); /* create icq if missing */ - if (unlikely(et->icq_cache && !icq)) + if ((rw_flags & REQ_ELVPRIV) && unlikely(et->icq_cache && !icq)) { icq = ioc_create_icq(q, gfp_mask); + if (!icq) + goto fail_icq; + } - /* rqs are guaranteed to have icq on elv_set_request() if requested */ - if (likely(!et->icq_cache || icq)) - rq = blk_alloc_request(q, icq, rw_flags, gfp_mask); + rq = blk_alloc_request(q, icq, rw_flags, gfp_mask); +fail_icq: if (unlikely(!rq)) { /* * Allocation failed presumably due to memory. Undo anything @@ -1210,7 +1212,6 @@ static bool bio_attempt_back_merge(struct request_queue *q, struct request *req, req->ioprio = ioprio_best(req->ioprio, bio_prio(bio)); drive_stat_acct(req, 0); - elv_bio_merged(q, req, bio); return true; } @@ -1241,7 +1242,6 @@ static bool bio_attempt_front_merge(struct request_queue *q, req->ioprio = ioprio_best(req->ioprio, bio_prio(bio)); drive_stat_acct(req, 0); - elv_bio_merged(q, req, bio); return true; } @@ -1255,13 +1255,12 @@ static bool bio_attempt_front_merge(struct request_queue *q, * on %current's plugged list. Returns %true if merge was successful, * otherwise %false. * - * This function is called without @q->queue_lock; however, elevator is - * accessed iff there already are requests on the plugged list which in - * turn guarantees validity of the elevator. - * - * Note that, on successful merge, elevator operation - * elevator_bio_merged_fn() will be called without queue lock. Elevator - * must be ready for this. + * Plugging coalesces IOs from the same issuer for the same purpose without + * going through @q->queue_lock. As such it's more of an issuing mechanism + * than scheduling, and the request, while may have elvpriv data, is not + * added on the elevator at this point. In addition, we don't have + * reliable access to the elevator outside queue lock. Only check basic + * merging parameters without querying the elevator. */ static bool attempt_plug_merge(struct request_queue *q, struct bio *bio, unsigned int *request_count) @@ -1280,10 +1279,10 @@ static bool attempt_plug_merge(struct request_queue *q, struct bio *bio, (*request_count)++; - if (rq->q != q) + if (rq->q != q || !blk_rq_merge_ok(rq, bio)) continue; - el_ret = elv_try_merge(rq, bio); + el_ret = blk_try_merge(rq, bio); if (el_ret == ELEVATOR_BACK_MERGE) { ret = bio_attempt_back_merge(q, rq, bio); if (ret) @@ -1345,12 +1344,14 @@ void blk_queue_bio(struct request_queue *q, struct bio *bio) el_ret = elv_merge(q, &req, bio); if (el_ret == ELEVATOR_BACK_MERGE) { if (bio_attempt_back_merge(q, req, bio)) { + elv_bio_merged(q, req, bio); if (!attempt_back_merge(q, req)) elv_merged_request(q, req, el_ret); goto out_unlock; } } else if (el_ret == ELEVATOR_FRONT_MERGE) { if (bio_attempt_front_merge(q, req, bio)) { + elv_bio_merged(q, req, bio); if (!attempt_front_merge(q, req)) elv_merged_request(q, req, el_ret); goto out_unlock; |