Merge tag 'block-5.11-2020-12-23' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A few stragglers in here, but mostly just straight fixes. In
  particular:

   - Set of rnbd fixes for issues around changes for the merge window
     (Gioh, Jack, Md Haris Iqbal)

   - iocost tracepoint addition (Baolin)

   - Copyright/maintainers update (Christoph)

   - Remove old blk-mq fast path CPU warning (Daniel)

   - loop max_part fix (Josh)

   - Remote IPI threaded IRQ fix (Sebastian)

   - dasd stable fixes (Stefan)

   - bcache merge window fixup and style fixup (Yi, Zheng)"

* tag 'block-5.11-2020-12-23' of git://git.kernel.dk/linux-block:
  md/bcache: convert comma to semicolon
  bcache:remove a superfluous check in register_bcache
  block: update some copyrights
  block: remove a pointless self-reference in block_dev.c
  MAINTAINERS: add fs/block_dev.c to the block section
  blk-mq: Don't complete on a remote CPU in force threaded mode
  s390/dasd: fix list corruption of lcu list
  s390/dasd: fix list corruption of pavgroup group list
  s390/dasd: prevent inconsistent LCU device data
  s390/dasd: fix hanging device offline processing
  blk-iocost: Add iocg idle state tracepoint
  nbd: Respect max_part for all partition scans
  block/rnbd-clt: Does not request pdu to rtrs-clt
  block/rnbd-clt: Dynamically allocate sglist for rnbd_iu
  block/rnbd: Set write-back cache and fua same to the target device
  block/rnbd: Fix typos
  block/rnbd-srv: Protect dev session sysfs removal
  block/rnbd-clt: Fix possible memleak
  block/rnbd-clt: Get rid of warning regarding size argument in strlcpy
  blk-mq: Remove 'running from the wrong CPU' warning

MAINTAINERS

@@ -3199,6 +3199,7 @@ S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
 F:	block/
 F:	drivers/block/
+F:	fs/block_dev.c
 F:	include/linux/blk*
 F:	kernel/trace/blktrace.c
 F:	lib/sbitmap.c

block/blk-iocost.c

@@ -2185,6 +2185,9 @@ static int ioc_check_iocgs(struct ioc *ioc, struct ioc_now *now)
 							    WEIGHT_ONE);
 			}
 
+			TRACE_IOCG_PATH(iocg_idle, iocg, now,
+					atomic64_read(&iocg->active_period),
+					atomic64_read(&ioc->cur_period), vtime);
 			__propagate_weights(iocg, 0, 0, false, now);
 			list_del_init(&iocg->active_list);
 		}

block/blk-mq.c

@@ -650,6 +650,14 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq)
 	if (!IS_ENABLED(CONFIG_SMP) ||
 	    !test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags))
 		return false;
+	/*
+	 * With force threaded interrupts enabled, raising softirq from an SMP
+	 * function call will always result in waking the ksoftirqd thread.
+	 * This is probably worse than completing the request on a different
+	 * cache domain.
+	 */
+	if (force_irqthreads)
+		return false;
 
 	/* same CPU or cache domain?  Complete locally */
 	if (cpu == rq->mq_ctx->cpu ||
@@ -1495,31 +1503,6 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
 {
 	int srcu_idx;
 
-	/*
-	 * We should be running this queue from one of the CPUs that
-	 * are mapped to it.
-	 *
-	 * There are at least two related races now between setting
-	 * hctx->next_cpu from blk_mq_hctx_next_cpu() and running
-	 * __blk_mq_run_hw_queue():
-	 *
-	 * - hctx->next_cpu is found offline in blk_mq_hctx_next_cpu(),
-	 *   but later it becomes online, then this warning is harmless
-	 *   at all
-	 *
-	 * - hctx->next_cpu is found online in blk_mq_hctx_next_cpu(),
-	 *   but later it becomes offline, then the warning can't be
-	 *   triggered, and we depend on blk-mq timeout handler to
-	 *   handle dispatched requests to this hctx
-	 */
-	if (!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
-		cpu_online(hctx->next_cpu)) {
-		printk(KERN_WARNING "run queue from wrong CPU %d, hctx %s\n",
-			raw_smp_processor_id(),
-			cpumask_empty(hctx->cpumask) ? "inactive": "active");
-		dump_stack();
-	}
-
 	/*
 	 * We can't run the queue inline with ints disabled. Ensure that
 	 * we catch bad users of this early.

block/genhd.c

@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
  *  gendisk handling
+ *
+ * Portions Copyright (C) 2020 Christoph Hellwig
  */
 
 #include <linux/module.h>

block/partitions/core.c

@@ -2,6 +2,7 @@
 /*
  * Copyright (C) 1991-1998  Linus Torvalds
  * Re-organised Feb 1998 Russell King
+ * Copyright (C) 2020 Christoph Hellwig
  */
 #include <linux/fs.h>
 #include <linux/slab.h>

drivers/block/nbd.c

@@ -318,7 +318,8 @@ static int nbd_set_size(struct nbd_device *nbd, loff_t bytesize,
 	blk_queue_logical_block_size(nbd->disk->queue, blksize);
 	blk_queue_physical_block_size(nbd->disk->queue, blksize);
 
-	set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
+	if (max_part)
+		set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
 	if (!set_capacity_and_notify(nbd->disk, bytesize >> 9))
 		kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
 	return 0;
@@ -1476,9 +1477,11 @@ static int nbd_open(struct block_device *bdev, fmode_t mode)
 		refcount_set(&nbd->config_refs, 1);
 		refcount_inc(&nbd->refs);
 		mutex_unlock(&nbd->config_lock);
-		set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
+		if (max_part)
+			set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 	} else if (nbd_disconnected(nbd->config)) {
-		set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
+		if (max_part)
+			set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 	}
 out:
 	mutex_unlock(&nbd_index_mutex);

drivers/block/rnbd/rnbd-clt-sysfs.c

@@ -432,7 +432,7 @@ void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev)
 	 * i.e. rnbd_clt_unmap_dev_store() leading to a sysfs warning because
 	 * of sysfs link already was removed already.
 	 */
-	if (strlen(dev->blk_symlink_name) && try_module_get(THIS_MODULE)) {
+	if (dev->blk_symlink_name && try_module_get(THIS_MODULE)) {
 		sysfs_remove_link(rnbd_devs_kobj, dev->blk_symlink_name);
 		kfree(dev->blk_symlink_name);
 		module_put(THIS_MODULE);
@@ -521,7 +521,8 @@ static int rnbd_clt_add_dev_symlink(struct rnbd_clt_dev *dev)
 	return 0;
 
 out_err:
-	dev->blk_symlink_name[0] = '\0';
+	kfree(dev->blk_symlink_name);
+	dev->blk_symlink_name = NULL ;
 	return ret;
 }