Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[sfrench/cifs-2.6.git] / block / blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0dc9e341c2a72c65f6de9dbb5b019903ce95d723..9ce9cac16c3f5a7376f00b98e641e49d3e838592 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -95,18 +95,15 @@ static void blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
 {
        struct mq_inflight *mi = priv;
 
-       if (blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT) {
-               /*
-                * index[0] counts the specific partition that was asked
-                * for. index[1] counts the ones that are active on the
-                * whole device, so increment that if mi->part is indeed
-                * a partition, and not a whole device.
-                */
-               if (rq->part == mi->part)
-                       mi->inflight[0]++;
-               if (mi->part->partno)
-                       mi->inflight[1]++;
-       }
+       /*
+        * index[0] counts the specific partition that was asked for. index[1]
+        * counts the ones that are active on the whole device, so increment
+        * that if mi->part is indeed a partition, and not a whole device.
+        */
+       if (rq->part == mi->part)
+               mi->inflight[0]++;
+       if (mi->part->partno)
+               mi->inflight[1]++;
 }
 
 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
@@ -118,6 +115,25 @@ void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
        blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
 }
 
+static void blk_mq_check_inflight_rw(struct blk_mq_hw_ctx *hctx,
+                                    struct request *rq, void *priv,
+                                    bool reserved)
+{
+       struct mq_inflight *mi = priv;
+
+       if (rq->part == mi->part)
+               mi->inflight[rq_data_dir(rq)]++;
+}
+
+void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+                        unsigned int inflight[2])
+{
+       struct mq_inflight mi = { .part = part, .inflight = inflight, };
+
+       inflight[0] = inflight[1] = 0;
+       blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight_rw, &mi);
+}
+
 void blk_freeze_queue_start(struct request_queue *q)
 {
        int freeze_depth;
@@ -2042,6 +2058,13 @@ static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
 
        seqcount_init(&rq->gstate_seq);
        u64_stats_init(&rq->aborted_gstate_sync);
+       /*
+        * start gstate with gen 1 instead of 0, otherwise it will be equal
+        * to aborted_gstate, and be identified timed out by
+        * blk_mq_terminate_expired.
+        */
+       WRITE_ONCE(rq->gstate, MQ_RQ_GEN_INC);
+
        return 0;
 }
 
@@ -2329,7 +2352,7 @@ static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set,
 
 static void blk_mq_map_swqueue(struct request_queue *q)
 {
-       unsigned int i;
+       unsigned int i, hctx_idx;
        struct blk_mq_hw_ctx *hctx;
        struct blk_mq_ctx *ctx;
        struct blk_mq_tag_set *set = q->tag_set;
@@ -2346,8 +2369,23 @@ static void blk_mq_map_swqueue(struct request_queue *q)
 
        /*
         * Map software to hardware queues.
+        *
+        * If the cpu isn't present, the cpu is mapped to first hctx.
         */
        for_each_possible_cpu(i) {
+               hctx_idx = q->mq_map[i];
+               /* unmapped hw queue can be remapped after CPU topo changed */
+               if (!set->tags[hctx_idx] &&
+                   !__blk_mq_alloc_rq_map(set, hctx_idx)) {
+                       /*
+                        * If tags initialization fail for some hctx,
+                        * that hctx won't be brought online.  In this
+                        * case, remap the current ctx to hctx[0] which
+                        * is guaranteed to always have tags allocated
+                        */
+                       q->mq_map[i] = 0;
+               }
+
                ctx = per_cpu_ptr(q->queue_ctx, i);
                hctx = blk_mq_map_queue(q, i);
 
@@ -2359,8 +2397,21 @@ static void blk_mq_map_swqueue(struct request_queue *q)
        mutex_unlock(&q->sysfs_lock);
 
        queue_for_each_hw_ctx(q, hctx, i) {
-               /* every hctx should get mapped by at least one CPU */
-               WARN_ON(!hctx->nr_ctx);
+               /*
+                * If no software queues are mapped to this hardware queue,
+                * disable it and free the request entries.
+                */
+               if (!hctx->nr_ctx) {
+                       /* Never unmap queue 0.  We need it as a
+                        * fallback in case of a new remap fails
+                        * allocation
+                        */
+                       if (i && set->tags[i])
+                               blk_mq_free_map_and_requests(set, i);
+
+                       hctx->tags = NULL;
+                       continue;
+               }
 
                hctx->tags = set->tags[i];
                WARN_ON(!hctx->tags);