block: implement bio_associate_current()

[linux-2.6-block.git] / block / blk-core.c

diff --git a/block/blk-core.c b/block/blk-core.c
index b2d0fcd8f87fbb1ea9bab53d6a31800a05a11a92..991c1d6ef245f758260092033eac9267ebc39dbf 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -696,7 +696,7 @@ static inline void blk_free_request(struct request_queue *q, struct request *rq)
 }
 
 static struct request *
-blk_alloc_request(struct request_queue *q, struct io_cq *icq,
+blk_alloc_request(struct request_queue *q, struct bio *bio, struct io_cq *icq,
                  unsigned int flags, gfp_t gfp_mask)
 {
        struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
@@ -710,7 +710,7 @@ blk_alloc_request(struct request_queue *q, struct io_cq *icq,
 
        if (flags & REQ_ELVPRIV) {
                rq->elv.icq = icq;
-               if (unlikely(elv_set_request(q, rq, gfp_mask))) {
+               if (unlikely(elv_set_request(q, rq, bio, gfp_mask))) {
                        mempool_free(rq, q->rq.rq_pool);
                        return NULL;
                }
@@ -809,6 +809,22 @@ static bool blk_rq_should_init_elevator(struct bio *bio)
        return true;
 }
 
+/**
+ * rq_ioc - determine io_context for request allocation
+ * @bio: request being allocated is for this bio (can be %NULL)
+ *
+ * Determine io_context to use for request allocation for @bio.  May return
+ * %NULL if %current->io_context doesn't exist.
+ */
+static struct io_context *rq_ioc(struct bio *bio)
+{
+#ifdef CONFIG_BLK_CGROUP
+       if (bio && bio->bi_ioc)
+               return bio->bi_ioc;
+#endif
+       return current->io_context;
+}
+
 /**
  * get_request - get a free request
  * @q: request_queue to allocate request from
@@ -836,7 +852,7 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
        int may_queue;
 retry:
        et = q->elevator->type;
-       ioc = current->io_context;
+       ioc = rq_ioc(bio);
 
        if (unlikely(blk_queue_dead(q)))
                return NULL;
@@ -919,14 +935,16 @@ retry:
 
        /* create icq if missing */
        if ((rw_flags & REQ_ELVPRIV) && unlikely(et->icq_cache && !icq)) {
-               ioc = create_io_context(gfp_mask, q->node);
-               if (ioc)
-                       icq = ioc_create_icq(ioc, q, gfp_mask);
+               create_io_context(gfp_mask, q->node);
+               ioc = rq_ioc(bio);
+               if (!ioc)
+                       goto fail_alloc;
+               icq = ioc_create_icq(ioc, q, gfp_mask);
                if (!icq)
                        goto fail_alloc;
        }
 
-       rq = blk_alloc_request(q, icq, rw_flags, gfp_mask);
+       rq = blk_alloc_request(q, bio, icq, rw_flags, gfp_mask);
        if (unlikely(!rq))
                goto fail_alloc;