Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block

Pull core block updates from Jens Axboe:

 - disk events cleanup (Christoph)

 - gendisk and request queue allocation simplifications (Christoph)

 - bdev_disk_changed cleanups (Christoph)

 - IO priority improvements (Bart)

 - Chained bio completion trace fix (Edward)

 - blk-wbt fixes (Jan)

 - blk-wbt enable/disable fix (Zhang)

 - Scheduler dispatch improvements (Jan, Ming)

 - Shared tagset scheduler improvements (John)

 - BFQ updates (Paolo, Luca, Pietro)

 - BFQ lock inversion fix (Jan)

 - Documentation improvements (Kir)

 - CLONE_IO block cgroup fix (Tejun)

 - Remove of ancient and deprecated block dump feature (zhangyi)

 - Discard merge fix (Ming)

 - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas,
   Yang)

* tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits)
  block: fix discard request merge
  block/mq-deadline: Remove a WARN_ON_ONCE() call
  blk-mq: update hctx->dispatch_busy in case of real scheduler
  blk: Fix lock inversion between ioc lock and bfqd lock
  bfq: Remove merged request already in bfq_requests_merged()
  block: pass a gendisk to bdev_disk_changed
  block: move bdev_disk_changed
  block: add the events* attributes to disk_attrs
  block: move the disk events code to a separate file
  block: fix trace completion for chained bio
  block/partitions/msdos: Fix typo inidicator -> indicator
  block, bfq: reset waker pointer with shared queues
  block, bfq: check waker only for queues with no in-flight I/O
  block, bfq: avoid delayed merge of async queues
  block, bfq: boost throughput by extending queue-merging times
  block, bfq: consider also creation time in delayed stable merge
  block, bfq: fix delayed stable merge check
  block, bfq: let also stably merged queues enjoy weight raising
  blk-wbt: make sure throttle is enabled properly
  blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled()
  ...

1 files changed, 89 insertions, 40 deletions

diff --git a/block/partitions/core.c b/block/partitions/core.c
index dc60ecf46fe6..347c56a51d87 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -120,8 +120,7 @@ static void free_partitions(struct parsed_partitions *state)
 	kfree(state);
 }
 
-static struct parsed_partitions *check_partition(struct gendisk *hd,
-		struct block_device *bdev)
+static struct parsed_partitions *check_partition(struct gendisk *hd)
 {
 	struct parsed_partitions *state;
 	int i, res, err;
@@ -136,7 +135,7 @@ static struct parsed_partitions *check_partition(struct gendisk *hd,
 	}
 	state->pp_buf[0] = '\0';
 
-	state->bdev = bdev;
+	state->bdev = hd->part0;
 	disk_name(hd, 0, state->name);
 	snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
 	if (isdigit(state->name[strlen(state->name)-1]))
@@ -260,7 +259,8 @@ static const struct attribute_group *part_attr_groups[] = {
 
 static void part_release(struct device *dev)
 {
-	blk_free_devt(dev->devt);
+	if (MAJOR(dev->devt) == BLOCK_EXT_MAJOR)
+		blk_free_ext_minor(MINOR(dev->devt));
 	bdput(dev_to_bdev(dev));
 }
 
@@ -282,7 +282,7 @@ struct device_type part_type = {
 };
 
 /*
- * Must be called either with bd_mutex held, before a disk can be opened or
+ * Must be called either with open_mutex held, before a disk can be opened or
  * after all disk users are gone.
  */
 static void delete_partition(struct block_device *part)
@@ -311,7 +311,7 @@ static ssize_t whole_disk_show(struct device *dev,
 static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
 
 /*
- * Must be called either with bd_mutex held, before a disk can be opened or
+ * Must be called either with open_mutex held, before a disk can be opened or
  * after all disk users are gone.
  */
 static struct block_device *add_partition(struct gendisk *disk, int partno,
@@ -325,10 +325,8 @@ static struct block_device *add_partition(struct gendisk *disk, int partno,
 	const char *dname;
 	int err;
 
-	/*
-	 * disk_max_parts() won't be zero, either GENHD_FL_EXT_DEVT is set
-	 * or 'minors' is passed to alloc_disk().
-	 */
+	lockdep_assert_held(&disk->open_mutex);
+
 	if (partno >= disk_max_parts(disk))
 		return ERR_PTR(-EINVAL);
 
@@ -379,9 +377,15 @@ static struct block_device *add_partition(struct gendisk *disk, int partno,
 	pdev->type = &part_type;
 	pdev->parent = ddev;
 
-	err = blk_alloc_devt(bdev, &devt);
-	if (err)
-		goto out_put;
+	/* in consecutive minor range? */
+	if (bdev->bd_partno < disk->minors) {
+		devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
+	} else {
+		err = blk_alloc_ext_minor();
+		if (err < 0)
+			goto out_put;
+		devt = MKDEV(BLOCK_EXT_MAJOR, err);
+	}
 	pdev->devt = devt;
 
 	/* delay uevent until 'holders' subdir is created */
@@ -450,29 +454,27 @@ int bdev_add_partition(struct block_device *bdev, int partno,
 {
 	struct block_device *part;
 
-	mutex_lock(&bdev->bd_mutex);
+	mutex_lock(&bdev->bd_disk->open_mutex);
 	if (partition_overlaps(bdev->bd_disk, start, length, -1)) {
-		mutex_unlock(&bdev->bd_mutex);
+		mutex_unlock(&bdev->bd_disk->open_mutex);
 		return -EBUSY;
 	}
 
 	part = add_partition(bdev->bd_disk, partno, start, length,
 			ADDPART_FLAG_NONE, NULL);
-	mutex_unlock(&bdev->bd_mutex);
+	mutex_unlock(&bdev->bd_disk->open_mutex);
 	return PTR_ERR_OR_ZERO(part);
 }
 
 int bdev_del_partition(struct block_device *bdev, int partno)
 {
-	struct block_device *part;
-	int ret;
+	struct block_device *part = NULL;
+	int ret = -ENXIO;
 
-	part = bdget_disk(bdev->bd_disk, partno);
+	mutex_lock(&bdev->bd_disk->open_mutex);
+	part = xa_load(&bdev->bd_disk->part_tbl, partno);
 	if (!part)
-		return -ENXIO;
-
-	mutex_lock(&part->bd_mutex);
-	mutex_lock_nested(&bdev->bd_mutex, 1);
+		goto out_unlock;
 
 	ret = -EBUSY;
 	if (part->bd_openers)
@@ -481,24 +483,21 @@ int bdev_del_partition(struct block_device *bdev, int partno)
 	delete_partition(part);
 	ret = 0;
 out_unlock:
-	mutex_unlock(&bdev->bd_mutex);
-	mutex_unlock(&part->bd_mutex);
-	bdput(part);
+	mutex_unlock(&bdev->bd_disk->open_mutex);
 	return ret;
 }
 
 int bdev_resize_partition(struct block_device *bdev, int partno,
 		sector_t start, sector_t length)
 {
-	struct block_device *part;
-	int ret = 0;
+	struct block_device *part = NULL;
+	int ret = -ENXIO;
 
-	part = bdget_disk(bdev->bd_disk, partno);
+	mutex_lock(&bdev->bd_disk->open_mutex);
+	part = xa_load(&bdev->bd_disk->part_tbl, partno);
 	if (!part)
-		return -ENXIO;
+		goto out_unlock;
 
-	mutex_lock(&part->bd_mutex);
-	mutex_lock_nested(&bdev->bd_mutex, 1);
 	ret = -EINVAL;
 	if (start != part->bd_start_sect)
 		goto out_unlock;
@@ -511,9 +510,7 @@ int bdev_resize_partition(struct block_device *bdev, int partno,
 
 	ret = 0;
 out_unlock:
-	mutex_unlock(&part->bd_mutex);
-	mutex_unlock(&bdev->bd_mutex);
-	bdput(part);
+	mutex_unlock(&bdev->bd_disk->open_mutex);
 	return ret;
 }
 
@@ -538,7 +535,7 @@ void blk_drop_partitions(struct gendisk *disk)
 	struct block_device *part;
 	unsigned long idx;
 
-	lockdep_assert_held(&disk->part0->bd_mutex);
+	lockdep_assert_held(&disk->open_mutex);
 
 	xa_for_each_start(&disk->part_tbl, idx, part, 1) {
 		if (!bdgrab(part))
@@ -548,7 +545,7 @@ void blk_drop_partitions(struct gendisk *disk)
 	}
 }
 
-static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
+static bool blk_add_partition(struct gendisk *disk,
 		struct parsed_partitions *state, int p)
 {
 	sector_t size = state->parts[p].size;
@@ -598,7 +595,7 @@ static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
 	return true;
 }
 
-int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
+static int blk_add_partitions(struct gendisk *disk)
 {
 	struct parsed_partitions *state;
 	int ret = -EAGAIN, p;
@@ -606,7 +603,7 @@ int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
 	if (!disk_part_scan_enabled(disk))
 		return 0;
 
-	state = check_partition(disk, bdev);
+	state = check_partition(disk);
 	if (!state)
 		return 0;
 	if (IS_ERR(state)) {
@@ -650,7 +647,7 @@ int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
 	kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 
 	for (p = 1; p < state->limit; p++)
-		if (!blk_add_partition(disk, bdev, state, p))
+		if (!blk_add_partition(disk, state, p))
 			goto out_free_state;
 
 	ret = 0;
@@ -659,6 +656,58 @@ out_free_state:
 	return ret;
 }
 
+int bdev_disk_changed(struct gendisk *disk, bool invalidate)
+{
+	int ret = 0;
+
+	lockdep_assert_held(&disk->open_mutex);
+
+	if (!(disk->flags & GENHD_FL_UP))
+		return -ENXIO;
+
+rescan:
+	if (disk->open_partitions)
+		return -EBUSY;
+	sync_blockdev(disk->part0);
+	invalidate_bdev(disk->part0);
+	blk_drop_partitions(disk);
+
+	clear_bit(GD_NEED_PART_SCAN, &disk->state);
+
+	/*
+	 * Historically we only set the capacity to zero for devices that
+	 * support partitions (independ of actually having partitions created).
+	 * Doing that is rather inconsistent, but changing it broke legacy
+	 * udisks polling for legacy ide-cdrom devices.  Use the crude check
+	 * below to get the sane behavior for most device while not breaking
+	 * userspace for this particular setup.
+	 */
+	if (invalidate) {
+		if (disk_part_scan_enabled(disk) ||
+		    !(disk->flags & GENHD_FL_REMOVABLE))
+			set_capacity(disk, 0);
+	}
+
+	if (get_capacity(disk)) {
+		ret = blk_add_partitions(disk);
+		if (ret == -EAGAIN)
+			goto rescan;
+	} else if (invalidate) {
+		/*
+		 * Tell userspace that the media / partition table may have
+		 * changed.
+		 */
+		kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+	}
+
+	return ret;
+}
+/*
+ * Only exported for loop and dasd for historic reasons.  Don't use in new
+ * code!
+ */
+EXPORT_SYMBOL_GPL(bdev_disk_changed);
+
 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
 {
 	struct address_space *mapping = state->bdev->bd_inode->i_mapping;