From 1543e317f1da31b75942316931e8f491a8920811 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Thu, 04 Jan 2024 10:08:02 +0000
Subject: [PATCH] disable FB

---
 kernel/block/blk-zoned.c |  585 ++++++++++++++++++++++++++++++++++++++--------------------
 1 files changed, 381 insertions(+), 204 deletions(-)

diff --git a/kernel/block/blk-zoned.c b/kernel/block/blk-zoned.c
index d33e89d..61b4522 100644
--- a/kernel/block/blk-zoned.c
+++ b/kernel/block/blk-zoned.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Zoned block device handling
  *
@@ -12,6 +13,44 @@
 #include <linux/module.h>
 #include <linux/rbtree.h>
 #include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/sched/mm.h>
+
+#include "blk.h"
+
+#define ZONE_COND_NAME(name) [BLK_ZONE_COND_##name] = #name
+static const char *const zone_cond_name[] = {
+	ZONE_COND_NAME(NOT_WP),
+	ZONE_COND_NAME(EMPTY),
+	ZONE_COND_NAME(IMP_OPEN),
+	ZONE_COND_NAME(EXP_OPEN),
+	ZONE_COND_NAME(CLOSED),
+	ZONE_COND_NAME(READONLY),
+	ZONE_COND_NAME(FULL),
+	ZONE_COND_NAME(OFFLINE),
+};
+#undef ZONE_COND_NAME
+
+/**
+ * blk_zone_cond_str - Return string XXX in BLK_ZONE_COND_XXX.
+ * @zone_cond: BLK_ZONE_COND_XXX.
+ *
+ * Description: Centralize block layer function to convert BLK_ZONE_COND_XXX
+ * into string format. Useful in the debugging and tracing zone conditions. For
+ * invalid BLK_ZONE_COND_XXX it returns string "UNKNOWN".
+ */
+const char *blk_zone_cond_str(enum blk_zone_cond zone_cond)
+{
+	static const char *zone_cond_str = "UNKNOWN";
+
+	if (zone_cond < ARRAY_SIZE(zone_cond_name) && zone_cond_name[zone_cond])
+		zone_cond_str = zone_cond_name[zone_cond];
+
+	return zone_cond_str;
+}
+EXPORT_SYMBOL_GPL(blk_zone_cond_str);
 
 static inline sector_t blk_zone_start(struct request_queue *q,
 				      sector_t sector)
@@ -43,6 +82,20 @@
 }
 EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
 
+bool blk_req_zone_write_trylock(struct request *rq)
+{
+	unsigned int zno = blk_rq_zone_no(rq);
+
+	if (test_and_set_bit(zno, rq->q->seq_zones_wlock))
+		return false;
+
+	WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
+	rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(blk_req_zone_write_trylock);
+
 void __blk_req_zone_write_lock(struct request *rq)
 {
 	if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),
@@ -63,238 +116,162 @@
 }
 EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
 
-/*
- * Check that a zone report belongs to the partition.
- * If yes, fix its start sector and write pointer, copy it in the
- * zone information array and return true. Return false otherwise.
+/**
+ * blkdev_nr_zones - Get number of zones
+ * @disk:	Target gendisk
+ *
+ * Return the total number of zones of a zoned block device.  For a block
+ * device without zone capabilities, the number of zones is always 0.
  */
-static bool blkdev_report_zone(struct block_device *bdev,
-			       struct blk_zone *rep,
-			       struct blk_zone *zone)
+unsigned int blkdev_nr_zones(struct gendisk *disk)
 {
-	sector_t offset = get_start_sect(bdev);
+	sector_t zone_sectors = blk_queue_zone_sectors(disk->queue);
 
-	if (rep->start < offset)
-		return false;
-
-	rep->start -= offset;
-	if (rep->start + rep->len > bdev->bd_part->nr_sects)
-		return false;
-
-	if (rep->type == BLK_ZONE_TYPE_CONVENTIONAL)
-		rep->wp = rep->start + rep->len;
-	else
-		rep->wp -= offset;
-	memcpy(zone, rep, sizeof(struct blk_zone));
-
-	return true;
+	if (!blk_queue_is_zoned(disk->queue))
+		return 0;
+	return (get_capacity(disk) + zone_sectors - 1) >> ilog2(zone_sectors);
 }
+EXPORT_SYMBOL_GPL(blkdev_nr_zones);
 
 /**
  * blkdev_report_zones - Get zones information
  * @bdev:	Target block device
  * @sector:	Sector from which to report zones
- * @zones:	Array of zone structures where to return the zones information
- * @nr_zones:	Number of zone structures in the zone array
- * @gfp_mask:	Memory allocation flags (for bio_alloc)
+ * @nr_zones:	Maximum number of zones to report
+ * @cb:		Callback function called for each reported zone
+ * @data:	Private data for the callback
  *
  * Description:
- *    Get zone information starting from the zone containing @sector.
- *    The number of zone information reported may be less than the number
- *    requested by @nr_zones. The number of zones actually reported is
- *    returned in @nr_zones.
+ *    Get zone information starting from the zone containing @sector for at most
+ *    @nr_zones, and call @cb for each zone reported by the device.
+ *    To report all zones in a device starting from @sector, the BLK_ALL_ZONES
+ *    constant can be passed to @nr_zones.
+ *    Returns the number of zones reported by the device, or a negative errno
+ *    value in case of failure.
+ *
+ *    Note: The caller must use memalloc_noXX_save/restore() calls to control
+ *    memory allocations done within this function.
  */
-int blkdev_report_zones(struct block_device *bdev,
-			sector_t sector,
-			struct blk_zone *zones,
-			unsigned int *nr_zones,
-			gfp_t gfp_mask)
+int blkdev_report_zones(struct block_device *bdev, sector_t sector,
+			unsigned int nr_zones, report_zones_cb cb, void *data)
 {
-	struct request_queue *q = bdev_get_queue(bdev);
-	struct blk_zone_report_hdr *hdr;
-	unsigned int nrz = *nr_zones;
-	struct page *page;
-	unsigned int nr_rep;
-	size_t rep_bytes;
-	unsigned int nr_pages;
-	struct bio *bio;
-	struct bio_vec *bv;
-	unsigned int i, n, nz;
-	unsigned int ofst;
-	void *addr;
-	int ret;
+	struct gendisk *disk = bdev->bd_disk;
+	sector_t capacity = get_capacity(disk);
 
-	if (!q)
-		return -ENXIO;
-
-	if (!blk_queue_is_zoned(q))
+	if (!blk_queue_is_zoned(bdev_get_queue(bdev)) ||
+	    WARN_ON_ONCE(!disk->fops->report_zones))
 		return -EOPNOTSUPP;
 
-	if (!nrz)
+	if (!nr_zones || sector >= capacity)
 		return 0;
 
-	if (sector > bdev->bd_part->nr_sects) {
-		*nr_zones = 0;
-		return 0;
-	}
-
-	/*
-	 * The zone report has a header. So make room for it in the
-	 * payload. Also make sure that the report fits in a single BIO
-	 * that will not be split down the stack.
-	 */
-	rep_bytes = sizeof(struct blk_zone_report_hdr) +
-		sizeof(struct blk_zone) * nrz;
-	rep_bytes = (rep_bytes + PAGE_SIZE - 1) & PAGE_MASK;
-	if (rep_bytes > (queue_max_sectors(q) << 9))
-		rep_bytes = queue_max_sectors(q) << 9;
-
-	nr_pages = min_t(unsigned int, BIO_MAX_PAGES,
-			 rep_bytes >> PAGE_SHIFT);
-	nr_pages = min_t(unsigned int, nr_pages,
-			 queue_max_segments(q));
-
-	bio = bio_alloc(gfp_mask, nr_pages);
-	if (!bio)
-		return -ENOMEM;
-
-	bio_set_dev(bio, bdev);
-	bio->bi_iter.bi_sector = blk_zone_start(q, sector);
-	bio_set_op_attrs(bio, REQ_OP_ZONE_REPORT, 0);
-
-	for (i = 0; i < nr_pages; i++) {
-		page = alloc_page(gfp_mask);
-		if (!page) {
-			ret = -ENOMEM;
-			goto out;
-		}
-		if (!bio_add_page(bio, page, PAGE_SIZE, 0)) {
-			__free_page(page);
-			break;
-		}
-	}
-
-	if (i == 0)
-		ret = -ENOMEM;
-	else
-		ret = submit_bio_wait(bio);
-	if (ret)
-		goto out;
-
-	/*
-	 * Process the report result: skip the header and go through the
-	 * reported zones to fixup and fixup the zone information for
-	 * partitions. At the same time, return the zone information into
-	 * the zone array.
-	 */
-	n = 0;
-	nz = 0;
-	nr_rep = 0;
-	bio_for_each_segment_all(bv, bio, i) {
-
-		if (!bv->bv_page)
-			break;
-
-		addr = kmap_atomic(bv->bv_page);
-
-		/* Get header in the first page */
-		ofst = 0;
-		if (!nr_rep) {
-			hdr = addr;
-			nr_rep = hdr->nr_zones;
-			ofst = sizeof(struct blk_zone_report_hdr);
-		}
-
-		/* Fixup and report zones */
-		while (ofst < bv->bv_len &&
-		       n < nr_rep && nz < nrz) {
-			if (blkdev_report_zone(bdev, addr + ofst, &zones[nz]))
-				nz++;
-			ofst += sizeof(struct blk_zone);
-			n++;
-		}
-
-		kunmap_atomic(addr);
-
-		if (n >= nr_rep || nz >= nrz)
-			break;
-
-	}
-
-	*nr_zones = nz;
-out:
-	bio_for_each_segment_all(bv, bio, i)
-		__free_page(bv->bv_page);
-	bio_put(bio);
-
-	return ret;
+	return disk->fops->report_zones(disk, sector, nr_zones, cb, data);
 }
 EXPORT_SYMBOL_GPL(blkdev_report_zones);
 
+static inline bool blkdev_allow_reset_all_zones(struct block_device *bdev,
+						sector_t sector,
+						sector_t nr_sectors)
+{
+	if (!blk_queue_zone_resetall(bdev_get_queue(bdev)))
+		return false;
+
+	/*
+	 * REQ_OP_ZONE_RESET_ALL can be executed only if the number of sectors
+	 * of the applicable zone range is the entire disk.
+	 */
+	return !sector && nr_sectors == get_capacity(bdev->bd_disk);
+}
+
 /**
- * blkdev_reset_zones - Reset zones write pointer
+ * blkdev_zone_mgmt - Execute a zone management operation on a range of zones
  * @bdev:	Target block device
- * @sector:	Start sector of the first zone to reset
- * @nr_sectors:	Number of sectors, at least the length of one zone
+ * @op:		Operation to be performed on the zones
+ * @sector:	Start sector of the first zone to operate on
+ * @nr_sectors:	Number of sectors, should be at least the length of one zone and
+ *		must be zone size aligned.
  * @gfp_mask:	Memory allocation flags (for bio_alloc)
  *
  * Description:
- *    Reset the write pointer of the zones contained in the range
+ *    Perform the specified operation on the range of zones specified by
  *    @sector..@sector+@nr_sectors. Specifying the entire disk sector range
  *    is valid, but the specified range should not contain conventional zones.
+ *    The operation to execute on each zone can be a zone reset, open, close
+ *    or finish request.
  */
-int blkdev_reset_zones(struct block_device *bdev,
-		       sector_t sector, sector_t nr_sectors,
-		       gfp_t gfp_mask)
+int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
+		     sector_t sector, sector_t nr_sectors,
+		     gfp_t gfp_mask)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
-	sector_t zone_sectors;
+	sector_t zone_sectors = blk_queue_zone_sectors(q);
+	sector_t capacity = get_capacity(bdev->bd_disk);
 	sector_t end_sector = sector + nr_sectors;
-	struct bio *bio;
+	struct bio *bio = NULL;
 	int ret;
-
-	if (!q)
-		return -ENXIO;
 
 	if (!blk_queue_is_zoned(q))
 		return -EOPNOTSUPP;
 
-	if (end_sector > bdev->bd_part->nr_sects)
+	if (bdev_read_only(bdev))
+		return -EPERM;
+
+	if (!op_is_zone_mgmt(op))
+		return -EOPNOTSUPP;
+
+	if (end_sector <= sector || end_sector > capacity)
 		/* Out of range */
 		return -EINVAL;
 
 	/* Check alignment (handle eventual smaller last zone) */
-	zone_sectors = blk_queue_zone_sectors(q);
 	if (sector & (zone_sectors - 1))
 		return -EINVAL;
 
-	if ((nr_sectors & (zone_sectors - 1)) &&
-	    end_sector != bdev->bd_part->nr_sects)
+	if ((nr_sectors & (zone_sectors - 1)) && end_sector != capacity)
 		return -EINVAL;
 
 	while (sector < end_sector) {
-
-		bio = bio_alloc(gfp_mask, 0);
-		bio->bi_iter.bi_sector = sector;
+		bio = blk_next_bio(bio, 0, gfp_mask);
 		bio_set_dev(bio, bdev);
-		bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
 
-		ret = submit_bio_wait(bio);
-		bio_put(bio);
+		/*
+		 * Special case for the zone reset operation that reset all
+		 * zones, this is useful for applications like mkfs.
+		 */
+		if (op == REQ_OP_ZONE_RESET &&
+		    blkdev_allow_reset_all_zones(bdev, sector, nr_sectors)) {
+			bio->bi_opf = REQ_OP_ZONE_RESET_ALL | REQ_SYNC;
+			break;
+		}
 
-		if (ret)
-			return ret;
-
+		bio->bi_opf = op | REQ_SYNC;
+		bio->bi_iter.bi_sector = sector;
 		sector += zone_sectors;
 
 		/* This may take a while, so be nice to others */
 		cond_resched();
-
 	}
 
+	ret = submit_bio_wait(bio);
+	bio_put(bio);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(blkdev_zone_mgmt);
+
+struct zone_report_args {
+	struct blk_zone __user *zones;
+};
+
+static int blkdev_copy_zone_to_user(struct blk_zone *zone, unsigned int idx,
+				    void *data)
+{
+	struct zone_report_args *args = data;
+
+	if (copy_to_user(&args->zones[idx], zone, sizeof(struct blk_zone)))
+		return -EFAULT;
 	return 0;
 }
-EXPORT_SYMBOL_GPL(blkdev_reset_zones);
 
 /*
  * BLKREPORTZONE ioctl processing.
@@ -304,9 +281,9 @@
 			      unsigned int cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
+	struct zone_report_args args;
 	struct request_queue *q;
 	struct blk_zone_report rep;
-	struct blk_zone *zones;
 	int ret;
 
 	if (!argp)
@@ -325,47 +302,47 @@
 	if (!rep.nr_zones)
 		return -EINVAL;
 
-	if (rep.nr_zones > INT_MAX / sizeof(struct blk_zone))
-		return -ERANGE;
+	args.zones = argp + sizeof(struct blk_zone_report);
+	ret = blkdev_report_zones(bdev, rep.sector, rep.nr_zones,
+				  blkdev_copy_zone_to_user, &args);
+	if (ret < 0)
+		return ret;
 
-	zones = kvmalloc_array(rep.nr_zones, sizeof(struct blk_zone),
-			       GFP_KERNEL | __GFP_ZERO);
-	if (!zones)
-		return -ENOMEM;
+	rep.nr_zones = ret;
+	rep.flags = BLK_ZONE_REP_CAPACITY;
+	if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report)))
+		return -EFAULT;
+	return 0;
+}
 
-	ret = blkdev_report_zones(bdev, rep.sector,
-				  zones, &rep.nr_zones,
-				  GFP_KERNEL);
-	if (ret)
-		goto out;
+static int blkdev_truncate_zone_range(struct block_device *bdev, fmode_t mode,
+				      const struct blk_zone_range *zrange)
+{
+	loff_t start, end;
 
-	if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
-		ret = -EFAULT;
-		goto out;
-	}
+	if (zrange->sector + zrange->nr_sectors <= zrange->sector ||
+	    zrange->sector + zrange->nr_sectors > get_capacity(bdev->bd_disk))
+		/* Out of range */
+		return -EINVAL;
 
-	if (rep.nr_zones) {
-		if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
-				 sizeof(struct blk_zone) * rep.nr_zones))
-			ret = -EFAULT;
-	}
+	start = zrange->sector << SECTOR_SHIFT;
+	end = ((zrange->sector + zrange->nr_sectors) << SECTOR_SHIFT) - 1;
 
- out:
-	kvfree(zones);
-
-	return ret;
+	return truncate_bdev_range(bdev, mode, start, end);
 }
 
 /*
- * BLKRESETZONE ioctl processing.
+ * BLKRESETZONE, BLKOPENZONE, BLKCLOSEZONE and BLKFINISHZONE ioctl processing.
  * Called from blkdev_ioctl.
  */
-int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
-			     unsigned int cmd, unsigned long arg)
+int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
+			   unsigned int cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	struct request_queue *q;
 	struct blk_zone_range zrange;
+	enum req_opf op;
+	int ret;
 
 	if (!argp)
 		return -EINVAL;
@@ -383,6 +360,206 @@
 	if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
 		return -EFAULT;
 
-	return blkdev_reset_zones(bdev, zrange.sector, zrange.nr_sectors,
-				  GFP_KERNEL);
+	switch (cmd) {
+	case BLKRESETZONE:
+		op = REQ_OP_ZONE_RESET;
+
+		/* Invalidate the page cache, including dirty pages. */
+		ret = blkdev_truncate_zone_range(bdev, mode, &zrange);
+		if (ret)
+			return ret;
+		break;
+	case BLKOPENZONE:
+		op = REQ_OP_ZONE_OPEN;
+		break;
+	case BLKCLOSEZONE:
+		op = REQ_OP_ZONE_CLOSE;
+		break;
+	case BLKFINISHZONE:
+		op = REQ_OP_ZONE_FINISH;
+		break;
+	default:
+		return -ENOTTY;
+	}
+
+	ret = blkdev_zone_mgmt(bdev, op, zrange.sector, zrange.nr_sectors,
+			       GFP_KERNEL);
+
+	/*
+	 * Invalidate the page cache again for zone reset: writes can only be
+	 * direct for zoned devices so concurrent writes would not add any page
+	 * to the page cache after/during reset. The page cache may be filled
+	 * again due to concurrent reads though and dropping the pages for
+	 * these is fine.
+	 */
+	if (!ret && cmd == BLKRESETZONE)
+		ret = blkdev_truncate_zone_range(bdev, mode, &zrange);
+
+	return ret;
 }
+
+static inline unsigned long *blk_alloc_zone_bitmap(int node,
+						   unsigned int nr_zones)
+{
+	return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
+			    GFP_NOIO, node);
+}
+
+void blk_queue_free_zone_bitmaps(struct request_queue *q)
+{
+	kfree(q->conv_zones_bitmap);
+	q->conv_zones_bitmap = NULL;
+	kfree(q->seq_zones_wlock);
+	q->seq_zones_wlock = NULL;
+}
+
+struct blk_revalidate_zone_args {
+	struct gendisk	*disk;
+	unsigned long	*conv_zones_bitmap;
+	unsigned long	*seq_zones_wlock;
+	unsigned int	nr_zones;
+	sector_t	zone_sectors;
+	sector_t	sector;
+};
+
+/*
+ * Helper function to check the validity of zones of a zoned block device.
+ */
+static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
+				  void *data)
+{
+	struct blk_revalidate_zone_args *args = data;
+	struct gendisk *disk = args->disk;
+	struct request_queue *q = disk->queue;
+	sector_t capacity = get_capacity(disk);
+
+	/*
+	 * All zones must have the same size, with the exception on an eventual
+	 * smaller last zone.
+	 */
+	if (zone->start == 0) {
+		if (zone->len == 0 || !is_power_of_2(zone->len)) {
+			pr_warn("%s: Invalid zoned device with non power of two zone size (%llu)\n",
+				disk->disk_name, zone->len);
+			return -ENODEV;
+		}
+
+		args->zone_sectors = zone->len;
+		args->nr_zones = (capacity + zone->len - 1) >> ilog2(zone->len);
+	} else if (zone->start + args->zone_sectors < capacity) {
+		if (zone->len != args->zone_sectors) {
+			pr_warn("%s: Invalid zoned device with non constant zone size\n",
+				disk->disk_name);
+			return -ENODEV;
+		}
+	} else {
+		if (zone->len > args->zone_sectors) {
+			pr_warn("%s: Invalid zoned device with larger last zone size\n",
+				disk->disk_name);
+			return -ENODEV;
+		}
+	}
+
+	/* Check for holes in the zone report */
+	if (zone->start != args->sector) {
+		pr_warn("%s: Zone gap at sectors %llu..%llu\n",
+			disk->disk_name, args->sector, zone->start);
+		return -ENODEV;
+	}
+
+	/* Check zone type */
+	switch (zone->type) {
+	case BLK_ZONE_TYPE_CONVENTIONAL:
+		if (!args->conv_zones_bitmap) {
+			args->conv_zones_bitmap =
+				blk_alloc_zone_bitmap(q->node, args->nr_zones);
+			if (!args->conv_zones_bitmap)
+				return -ENOMEM;
+		}
+		set_bit(idx, args->conv_zones_bitmap);
+		break;
+	case BLK_ZONE_TYPE_SEQWRITE_REQ:
+	case BLK_ZONE_TYPE_SEQWRITE_PREF:
+		if (!args->seq_zones_wlock) {
+			args->seq_zones_wlock =
+				blk_alloc_zone_bitmap(q->node, args->nr_zones);
+			if (!args->seq_zones_wlock)
+				return -ENOMEM;
+		}
+		break;
+	default:
+		pr_warn("%s: Invalid zone type 0x%x at sectors %llu\n",
+			disk->disk_name, (int)zone->type, zone->start);
+		return -ENODEV;
+	}
+
+	args->sector += zone->len;
+	return 0;
+}
+
+/**
+ * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
+ * @disk:	Target disk
+ * @update_driver_data:	Callback to update driver data on the frozen disk
+ *
+ * Helper function for low-level device drivers to (re) allocate and initialize
+ * a disk request queue zone bitmaps. This functions should normally be called
+ * within the disk ->revalidate method for blk-mq based drivers.  For BIO based
+ * drivers only q->nr_zones needs to be updated so that the sysfs exposed value
+ * is correct.
+ * If the @update_driver_data callback function is not NULL, the callback is
+ * executed with the device request queue frozen after all zones have been
+ * checked.
+ */
+int blk_revalidate_disk_zones(struct gendisk *disk,
+			      void (*update_driver_data)(struct gendisk *disk))
+{
+	struct request_queue *q = disk->queue;
+	struct blk_revalidate_zone_args args = {
+		.disk		= disk,
+	};
+	unsigned int noio_flag;
+	int ret;
+
+	if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
+		return -EIO;
+	if (WARN_ON_ONCE(!queue_is_mq(q)))
+		return -EIO;
+
+	if (!get_capacity(disk))
+		return -EIO;
+
+	/*
+	 * Ensure that all memory allocations in this context are done as if
+	 * GFP_NOIO was specified.
+	 */
+	noio_flag = memalloc_noio_save();
+	ret = disk->fops->report_zones(disk, 0, UINT_MAX,
+				       blk_revalidate_zone_cb, &args);
+	memalloc_noio_restore(noio_flag);
+
+	/*
+	 * Install the new bitmaps and update nr_zones only once the queue is
+	 * stopped and all I/Os are completed (i.e. a scheduler is not
+	 * referencing the bitmaps).
+	 */
+	blk_mq_freeze_queue(q);
+	if (ret >= 0) {
+		blk_queue_chunk_sectors(q, args.zone_sectors);
+		q->nr_zones = args.nr_zones;
+		swap(q->seq_zones_wlock, args.seq_zones_wlock);
+		swap(q->conv_zones_bitmap, args.conv_zones_bitmap);
+		if (update_driver_data)
+			update_driver_data(disk);
+		ret = 0;
+	} else {
+		pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
+		blk_queue_free_zone_bitmaps(q);
+	}
+	blk_mq_unfreeze_queue(q);
+
+	kfree(args.seq_zones_wlock);
+	kfree(args.conv_zones_bitmap);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);

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