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authorDavid S. Miller <davem@davemloft.net>2012-02-19 21:03:15 (GMT)
committerDavid S. Miller <davem@davemloft.net>2012-02-19 21:03:15 (GMT)
commit32efe08d77f5902ce7315fc9003c010ffffb8268 (patch)
tree40a88e6bae4e797cafce33f16a25e350c038f9bb /block/blk-core.c
parentda1943164677ae2cdd630196b79089d476726348 (diff)
parentb01543dfe67bb1d191998e90d20534dc354de059 (diff)
downloadlinux-fsl-qoriq-32efe08d77f5902ce7315fc9003c010ffffb8268.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c Small minor conflict in bnx2x, wherein one commit changed how statistics were stored in software, and another commit fixed endianness bugs wrt. reading the values provided by the chip in memory. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'block/blk-core.c')
-rw-r--r--block/blk-core.c33
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;