---

yaml
---
r: 309278
b: refs/heads/master
c: aaf7c68
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 29e2b09ab5fa790514d47838f3c05497130908b3
+refs/heads/master: aaf7c680682f1999ef2e574f743c45d1674a8b8a

trunk/block/blk-core.c

@@ -29,6 +29,7 @@
 #include <linux/fault-inject.h>
 #include <linux/list_sort.h>
 #include <linux/delay.h>
+#include <linux/ratelimit.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/block.h>
@@ -930,17 +931,6 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
 		rw_flags |= REQ_IO_STAT;
 	spin_unlock_irq(q->queue_lock);
 
-	/* create icq if missing */
-	if ((rw_flags & REQ_ELVPRIV) && unlikely(et->icq_cache && !icq)) {
-		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;
-	}
-
 	/* allocate and init request */
 	rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
 	if (!rq)
@@ -949,17 +939,28 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
 	blk_rq_init(q, rq);
 	rq->cmd_flags = rw_flags | REQ_ALLOCED;
 
+	/* init elvpriv */
 	if (rw_flags & REQ_ELVPRIV) {
-		rq->elv.icq = icq;
-		if (unlikely(elv_set_request(q, rq, bio, gfp_mask))) {
-			mempool_free(rq, q->rq.rq_pool);
-			goto fail_alloc;
+		if (unlikely(et->icq_cache && !icq)) {
+			create_io_context(gfp_mask, q->node);
+			ioc = rq_ioc(bio);
+			if (!ioc)
+				goto fail_elvpriv;
+
+			icq = ioc_create_icq(ioc, q, gfp_mask);
+			if (!icq)
+				goto fail_elvpriv;
 		}
-		/* @rq->elv.icq holds on to io_context until @rq is freed */
+
+		rq->elv.icq = icq;
+		if (unlikely(elv_set_request(q, rq, bio, gfp_mask)))
+			goto fail_elvpriv;
+
+		/* @rq->elv.icq holds io_context until @rq is freed */
 		if (icq)
 			get_io_context(icq->ioc);
 	}
-
+out:
 	/*
 	 * ioc may be NULL here, and ioc_batching will be false. That's
 	 * OK, if the queue is under the request limit then requests need
@@ -972,6 +973,24 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
 	trace_block_getrq(q, bio, rw_flags & 1);
 	return rq;
 
+fail_elvpriv:
+	/*
+	 * elvpriv init failed.  ioc, icq and elvpriv aren't mempool backed
+	 * and may fail indefinitely under memory pressure and thus
+	 * shouldn't stall IO.  Treat this request as !elvpriv.  This will
+	 * disturb iosched and blkcg but weird is bettern than dead.
+	 */
+	printk_ratelimited(KERN_WARNING "%s: request aux data allocation failed, iosched may be disturbed\n",
+			   dev_name(q->backing_dev_info.dev));
+
+	rq->cmd_flags &= ~REQ_ELVPRIV;
+	rq->elv.icq = NULL;
+
+	spin_lock_irq(q->queue_lock);
+	rl->elvpriv--;
+	spin_unlock_irq(q->queue_lock);
+	goto out;
+
 fail_alloc:
 	/*
 	 * Allocation failed presumably due to memory. Undo anything we