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authorBart Van Assche <bart.vanassche@wdc.com>2017-11-09 10:49:54 -0800
committerJens Axboe <axboe@kernel.dk>2017-11-10 19:53:25 -0700
commit6a15674d1e90917f1723a814e2e8c949000440f7 (patch)
tree3ef924c704f4c3af2713b778508e0af1a67c3154 /block
parent055f6e18e08f5b7fd98171fce857a0bad87a919d (diff)
downloadlinux-stericsson-6a15674d1e90917f1723a814e2e8c949000440f7.tar.gz
block: Introduce blk_get_request_flags()
A side effect of this patch is that the GFP mask that is passed to several allocation functions in the legacy block layer is changed from GFP_KERNEL into __GFP_DIRECT_RECLAIM. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Martin Steigerwald <martin@lichtvoll.de> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-core.c50
1 files changed, 35 insertions, 15 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index a4362849059a..0f7093dfc010 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1160,7 +1160,7 @@ int blk_update_nr_requests(struct request_queue *q, unsigned int nr)
* @rl: request list to allocate from
* @op: operation and flags
* @bio: bio to allocate request for (can be %NULL)
- * @gfp_mask: allocation mask
+ * @flags: BLQ_MQ_REQ_* flags
*
* Get a free request from @q. This function may fail under memory
* pressure or if @q is dead.
@@ -1170,7 +1170,7 @@ int blk_update_nr_requests(struct request_queue *q, unsigned int nr)
* Returns request pointer on success, with @q->queue_lock *not held*.
*/
static struct request *__get_request(struct request_list *rl, unsigned int op,
- struct bio *bio, gfp_t gfp_mask)
+ struct bio *bio, unsigned int flags)
{
struct request_queue *q = rl->q;
struct request *rq;
@@ -1179,6 +1179,8 @@ static struct request *__get_request(struct request_list *rl, unsigned int op,
struct io_cq *icq = NULL;
const bool is_sync = op_is_sync(op);
int may_queue;
+ gfp_t gfp_mask = flags & BLK_MQ_REQ_NOWAIT ? GFP_ATOMIC :
+ __GFP_DIRECT_RECLAIM;
req_flags_t rq_flags = RQF_ALLOCED;
lockdep_assert_held(q->queue_lock);
@@ -1339,7 +1341,7 @@ rq_starved:
* @q: request_queue to allocate request from
* @op: operation and flags
* @bio: bio to allocate request for (can be %NULL)
- * @gfp_mask: allocation mask
+ * @flags: BLK_MQ_REQ_* flags.
*
* Get a free request from @q. If %__GFP_DIRECT_RECLAIM is set in @gfp_mask,
* this function keeps retrying under memory pressure and fails iff @q is dead.
@@ -1349,7 +1351,7 @@ rq_starved:
* Returns request pointer on success, with @q->queue_lock *not held*.
*/
static struct request *get_request(struct request_queue *q, unsigned int op,
- struct bio *bio, gfp_t gfp_mask)
+ struct bio *bio, unsigned int flags)
{
const bool is_sync = op_is_sync(op);
DEFINE_WAIT(wait);
@@ -1361,7 +1363,7 @@ static struct request *get_request(struct request_queue *q, unsigned int op,
rl = blk_get_rl(q, bio); /* transferred to @rq on success */
retry:
- rq = __get_request(rl, op, bio, gfp_mask);
+ rq = __get_request(rl, op, bio, flags);
if (!IS_ERR(rq))
return rq;
@@ -1370,7 +1372,7 @@ retry:
return ERR_PTR(-EAGAIN);
}
- if (!gfpflags_allow_blocking(gfp_mask) || unlikely(blk_queue_dying(q))) {
+ if ((flags & BLK_MQ_REQ_NOWAIT) || unlikely(blk_queue_dying(q))) {
blk_put_rl(rl);
return rq;
}
@@ -1397,10 +1399,13 @@ retry:
goto retry;
}
+/* flags: BLK_MQ_REQ_PREEMPT and/or BLK_MQ_REQ_NOWAIT. */
static struct request *blk_old_get_request(struct request_queue *q,
- unsigned int op, gfp_t gfp_mask)
+ unsigned int op, unsigned int flags)
{
struct request *rq;
+ gfp_t gfp_mask = flags & BLK_MQ_REQ_NOWAIT ? GFP_ATOMIC :
+ __GFP_DIRECT_RECLAIM;
int ret = 0;
WARN_ON_ONCE(q->mq_ops);
@@ -1413,7 +1418,7 @@ static struct request *blk_old_get_request(struct request_queue *q,
if (ret)
return ERR_PTR(ret);
spin_lock_irq(q->queue_lock);
- rq = get_request(q, op, NULL, gfp_mask);
+ rq = get_request(q, op, NULL, flags);
if (IS_ERR(rq)) {
spin_unlock_irq(q->queue_lock);
blk_queue_exit(q);
@@ -1427,25 +1432,40 @@ static struct request *blk_old_get_request(struct request_queue *q,
return rq;
}
-struct request *blk_get_request(struct request_queue *q, unsigned int op,
- gfp_t gfp_mask)
+/**
+ * blk_get_request_flags - allocate a request
+ * @q: request queue to allocate a request for
+ * @op: operation (REQ_OP_*) and REQ_* flags, e.g. REQ_SYNC.
+ * @flags: BLK_MQ_REQ_* flags, e.g. BLK_MQ_REQ_NOWAIT.
+ */
+struct request *blk_get_request_flags(struct request_queue *q, unsigned int op,
+ unsigned int flags)
{
struct request *req;
+ WARN_ON_ONCE(op & REQ_NOWAIT);
+ WARN_ON_ONCE(flags & ~BLK_MQ_REQ_NOWAIT);
+
if (q->mq_ops) {
- req = blk_mq_alloc_request(q, op,
- (gfp_mask & __GFP_DIRECT_RECLAIM) ?
- 0 : BLK_MQ_REQ_NOWAIT);
+ req = blk_mq_alloc_request(q, op, flags);
if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn)
q->mq_ops->initialize_rq_fn(req);
} else {
- req = blk_old_get_request(q, op, gfp_mask);
+ req = blk_old_get_request(q, op, flags);
if (!IS_ERR(req) && q->initialize_rq_fn)
q->initialize_rq_fn(req);
}
return req;
}
+EXPORT_SYMBOL(blk_get_request_flags);
+
+struct request *blk_get_request(struct request_queue *q, unsigned int op,
+ gfp_t gfp_mask)
+{
+ return blk_get_request_flags(q, op, gfp_mask & __GFP_DIRECT_RECLAIM ?
+ 0 : BLK_MQ_REQ_NOWAIT);
+}
EXPORT_SYMBOL(blk_get_request);
/**
@@ -1871,7 +1891,7 @@ get_rq:
* Returns with the queue unlocked.
*/
blk_queue_enter_live(q);
- req = get_request(q, bio->bi_opf, bio, GFP_NOIO);
+ req = get_request(q, bio->bi_opf, bio, 0);
if (IS_ERR(req)) {
blk_queue_exit(q);
__wbt_done(q->rq_wb, wb_acct);