diff options
Diffstat (limited to 'block/blk-core.c')
-rw-r--r-- | block/blk-core.c | 48 |
1 files changed, 0 insertions, 48 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index ea70e6c80cd3..435af2378614 100644 --- a/block/blk-core.c +++ b/block/blk-core.c | |||
@@ -1010,54 +1010,6 @@ static void add_acct_request(struct request_queue *q, struct request *rq, | |||
1010 | __elv_add_request(q, rq, where); | 1010 | __elv_add_request(q, rq, where); |
1011 | } | 1011 | } |
1012 | 1012 | ||
1013 | /** | ||
1014 | * blk_insert_request - insert a special request into a request queue | ||
1015 | * @q: request queue where request should be inserted | ||
1016 | * @rq: request to be inserted | ||
1017 | * @at_head: insert request at head or tail of queue | ||
1018 | * @data: private data | ||
1019 | * | ||
1020 | * Description: | ||
1021 | * Many block devices need to execute commands asynchronously, so they don't | ||
1022 | * block the whole kernel from preemption during request execution. This is | ||
1023 | * accomplished normally by inserting aritficial requests tagged as | ||
1024 | * REQ_TYPE_SPECIAL in to the corresponding request queue, and letting them | ||
1025 | * be scheduled for actual execution by the request queue. | ||
1026 | * | ||
1027 | * We have the option of inserting the head or the tail of the queue. | ||
1028 | * Typically we use the tail for new ioctls and so forth. We use the head | ||
1029 | * of the queue for things like a QUEUE_FULL message from a device, or a | ||
1030 | * host that is unable to accept a particular command. | ||
1031 | */ | ||
1032 | void blk_insert_request(struct request_queue *q, struct request *rq, | ||
1033 | int at_head, void *data) | ||
1034 | { | ||
1035 | int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK; | ||
1036 | unsigned long flags; | ||
1037 | |||
1038 | /* | ||
1039 | * tell I/O scheduler that this isn't a regular read/write (ie it | ||
1040 | * must not attempt merges on this) and that it acts as a soft | ||
1041 | * barrier | ||
1042 | */ | ||
1043 | rq->cmd_type = REQ_TYPE_SPECIAL; | ||
1044 | |||
1045 | rq->special = data; | ||
1046 | |||
1047 | spin_lock_irqsave(q->queue_lock, flags); | ||
1048 | |||
1049 | /* | ||
1050 | * If command is tagged, release the tag | ||
1051 | */ | ||
1052 | if (blk_rq_tagged(rq)) | ||
1053 | blk_queue_end_tag(q, rq); | ||
1054 | |||
1055 | add_acct_request(q, rq, where); | ||
1056 | __blk_run_queue(q); | ||
1057 | spin_unlock_irqrestore(q->queue_lock, flags); | ||
1058 | } | ||
1059 | EXPORT_SYMBOL(blk_insert_request); | ||
1060 | |||
1061 | static void part_round_stats_single(int cpu, struct hd_struct *part, | 1013 | static void part_round_stats_single(int cpu, struct hd_struct *part, |
1062 | unsigned long now) | 1014 | unsigned long now) |
1063 | { | 1015 | { |