block: rework zone reporting
Avoid the need to allocate a potentially large array of struct blk_zone
in the block layer by switching the ->report_zones method interface to
a callback model. Now the caller simply supplies a callback that is
executed on each reported zone, and private data for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index ae665e4..6fad6f3 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -101,44 +101,35 @@ 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
+ * @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.
- * The caller must use memalloc_noXX_save/restore() calls to control
- * memory allocations done within this function (zone array and command
- * buffer allocation by the device driver).
+ * 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)
+ unsigned int nr_zones, report_zones_cb cb, void *data)
{
- struct request_queue *q = bdev_get_queue(bdev);
struct gendisk *disk = bdev->bd_disk;
sector_t capacity = get_capacity(disk);
- if (!blk_queue_is_zoned(q))
+ if (!blk_queue_is_zoned(bdev_get_queue(bdev)) ||
+ WARN_ON_ONCE(!disk->fops->report_zones))
return -EOPNOTSUPP;
- /*
- * A block device that advertized itself as zoned must have a
- * report_zones method. If it does not have one defined, the device
- * driver has a bug. So warn about that.
- */
- if (WARN_ON_ONCE(!disk->fops->report_zones))
- return -EOPNOTSUPP;
-
- if (!*nr_zones || sector >= capacity) {
- *nr_zones = 0;
+ if (!nr_zones || sector >= capacity)
return 0;
- }
- *nr_zones = min(*nr_zones, __blkdev_nr_zones(q, capacity - sector));
-
- return disk->fops->report_zones(disk, sector, zones, nr_zones);
+ return disk->fops->report_zones(disk, sector, nr_zones, cb, data);
}
EXPORT_SYMBOL_GPL(blkdev_report_zones);
@@ -232,6 +223,20 @@ int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
}
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;
+}
+
/*
* BLKREPORTZONE ioctl processing.
* Called from blkdev_ioctl.
@@ -240,9 +245,9 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
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)
@@ -264,32 +269,16 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
if (!rep.nr_zones)
return -EINVAL;
- rep.nr_zones = min(blkdev_nr_zones(bdev), rep.nr_zones);
+ 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;
-
- ret = blkdev_report_zones(bdev, rep.sector, zones, &rep.nr_zones);
- if (ret)
- goto out;
-
- if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
- ret = -EFAULT;
- goto out;
- }
-
- if (rep.nr_zones) {
- if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
- sizeof(struct blk_zone) * rep.nr_zones))
- ret = -EFAULT;
- }
-
- out:
- kvfree(zones);
-
- return ret;
+ rep.nr_zones = ret;
+ if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report)))
+ return -EFAULT;
+ return 0;
}
/*
@@ -351,31 +340,6 @@ static inline unsigned long *blk_alloc_zone_bitmap(int node,
GFP_NOIO, node);
}
-/*
- * Allocate an array of struct blk_zone to get nr_zones zone information.
- * The allocated array may be smaller than nr_zones.
- */
-static struct blk_zone *blk_alloc_zones(unsigned int *nr_zones)
-{
- struct blk_zone *zones;
- size_t nrz = min(*nr_zones, BLK_ZONED_REPORT_MAX_ZONES);
-
- /*
- * GFP_KERNEL here is meaningless as the caller task context has
- * the PF_MEMALLOC_NOIO flag set in blk_revalidate_disk_zones()
- * with memalloc_noio_save().
- */
- zones = kvcalloc(nrz, sizeof(struct blk_zone), GFP_KERNEL);
- if (!zones) {
- *nr_zones = 0;
- return NULL;
- }
-
- *nr_zones = nrz;
-
- return zones;
-}
-
void blk_queue_free_zone_bitmaps(struct request_queue *q)
{
kfree(q->seq_zones_bitmap);
@@ -384,12 +348,21 @@ void blk_queue_free_zone_bitmaps(struct request_queue *q)
q->seq_zones_wlock = NULL;
}
+struct blk_revalidate_zone_args {
+ struct gendisk *disk;
+ unsigned long *seq_zones_bitmap;
+ unsigned long *seq_zones_wlock;
+ sector_t sector;
+};
+
/*
* Helper function to check the validity of zones of a zoned block device.
*/
-static bool blk_zone_valid(struct gendisk *disk, struct blk_zone *zone,
- sector_t *sector)
+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 zone_sectors = blk_queue_zone_sectors(q);
sector_t capacity = get_capacity(disk);
@@ -409,14 +382,14 @@ static bool blk_zone_valid(struct gendisk *disk, struct blk_zone *zone,
zone->len > zone_sectors) {
pr_warn("%s: Invalid zoned device with larger last zone size\n",
disk->disk_name);
- return false;
+ return -ENODEV;
}
/* Check for holes in the zone report */
- if (zone->start != *sector) {
+ if (zone->start != args->sector) {
pr_warn("%s: Zone gap at sectors %llu..%llu\n",
- disk->disk_name, *sector, zone->start);
- return false;
+ disk->disk_name, args->sector, zone->start);
+ return -ENODEV;
}
/* Check zone type */
@@ -428,12 +401,38 @@ static bool blk_zone_valid(struct gendisk *disk, struct blk_zone *zone,
default:
pr_warn("%s: Invalid zone type 0x%x at sectors %llu\n",
disk->disk_name, (int)zone->type, zone->start);
- return false;
+ return -ENODEV;
}
- *sector += zone->len;
+ if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL)
+ set_bit(idx, args->seq_zones_bitmap);
- return true;
+ args->sector += zone->len;
+ return 0;
+}
+
+static int blk_update_zone_info(struct gendisk *disk, unsigned int nr_zones,
+ struct blk_revalidate_zone_args *args)
+{
+ /*
+ * Ensure that all memory allocations in this context are done as
+ * if GFP_NOIO was specified.
+ */
+ unsigned int noio_flag = memalloc_noio_save();
+ struct request_queue *q = disk->queue;
+ int ret;
+
+ args->seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
+ if (!args->seq_zones_wlock)
+ return -ENOMEM;
+ args->seq_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
+ if (!args->seq_zones_bitmap)
+ return -ENOMEM;
+
+ ret = disk->fops->report_zones(disk, 0, nr_zones,
+ blk_revalidate_zone_cb, args);
+ memalloc_noio_restore(noio_flag);
+ return ret;
}
/**
@@ -449,11 +448,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
{
struct request_queue *q = disk->queue;
unsigned int nr_zones = __blkdev_nr_zones(q, get_capacity(disk));
- unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL;
- unsigned int i, rep_nr_zones = 0, z = 0, nrz;
- struct blk_zone *zones = NULL;
- unsigned int noio_flag;
- sector_t sector = 0;
+ struct blk_revalidate_zone_args args = { .disk = disk };
int ret = 0;
if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
@@ -468,82 +463,28 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
return 0;
}
- /*
- * Ensure that all memory allocations in this context are done as
- * if GFP_NOIO was specified.
- */
- noio_flag = memalloc_noio_save();
+ if (nr_zones)
+ ret = blk_update_zone_info(disk, nr_zones, &args);
- if (!nr_zones)
- goto update;
-
- /* Allocate bitmaps */
- ret = -ENOMEM;
- seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
- if (!seq_zones_wlock)
- goto out;
- seq_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
- if (!seq_zones_bitmap)
- goto out;
-
- /*
- * Get zone information to check the zones and initialize
- * seq_zones_bitmap.
- */
- rep_nr_zones = nr_zones;
- zones = blk_alloc_zones(&rep_nr_zones);
- if (!zones)
- goto out;
-
- while (z < nr_zones) {
- nrz = min(nr_zones - z, rep_nr_zones);
- ret = disk->fops->report_zones(disk, sector, zones, &nrz);
- if (ret)
- goto out;
- if (!nrz)
- break;
- for (i = 0; i < nrz; i++) {
- if (!blk_zone_valid(disk, &zones[i], §or)) {
- ret = -ENODEV;
- goto out;
- }
- if (zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL)
- set_bit(z, seq_zones_bitmap);
- z++;
- }
- }
-
- if (WARN_ON(z != nr_zones)) {
- ret = -EIO;
- goto out;
- }
-
-update:
/*
* Install the new bitmaps, making sure the queue is stopped and
* all I/Os are completed (i.e. a scheduler is not referencing the
* bitmaps).
*/
blk_mq_freeze_queue(q);
- q->nr_zones = nr_zones;
- swap(q->seq_zones_wlock, seq_zones_wlock);
- swap(q->seq_zones_bitmap, seq_zones_bitmap);
+ if (ret >= 0) {
+ q->nr_zones = nr_zones;
+ swap(q->seq_zones_wlock, args.seq_zones_wlock);
+ swap(q->seq_zones_bitmap, args.seq_zones_bitmap);
+ 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);
-out:
- memalloc_noio_restore(noio_flag);
-
- kvfree(zones);
- kfree(seq_zones_wlock);
- kfree(seq_zones_bitmap);
-
- if (ret) {
- pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
- blk_mq_freeze_queue(q);
- blk_queue_free_zone_bitmaps(q);
- blk_mq_unfreeze_queue(q);
- }
-
+ kfree(args.seq_zones_wlock);
+ kfree(args.seq_zones_bitmap);
return ret;
}
EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);