The conv_zones_bitmap field of struct gendisk is used to define a bitmap to identify the conventional zones of a zoned block device. The bit for a zone is set in this bitmap if the zone is a conventional one, that is, if the zone type is BLK_ZONE_TYPE_CONVENTIONAL. For such zone, this always corresponds to the zone condition BLK_ZONE_COND_NOT_WP. In other words, conv_zones_bitmap tracks a single condition of the zones of a zoned block device.
In preparation for tracking more zone conditions, change conv_zones_bitmap into an array of zone conditions, using 1 byte per zone. This increases the memory usage from 1 bit per zone to 1 byte per zone, that is, from 16 KiB to about 100 KiB for a 30 TB SMR HDD with 256 MiB zones. This is a trade-off to allow fast cached report zones later on top of this change. Rename the conv_zones_bitmap field of struct gendisk to zones_cond. Add a blk_revalidate_zone_cond() function to initialize the zones_cond array of a disk during device scan and to update it on device revalidation. Move the allocation of the zones_cond array to disk_revalidate_zone_resources(), making sure that this array is always allocated, even for devices that do not need zone write plugs (zone resources), to ensure that bdev_zone_is_seq() can be re-implemented to use the zone condition array in place of the conv zones bitmap. Finally, the function bdev_zone_is_seq() is rewritten to use a test on the condition of the target zone. Signed-off-by: Damien Le Moal <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> --- block/blk-zoned.c | 153 +++++++++++++++++++++++++++++------------ include/linux/blkdev.h | 37 +++------- 2 files changed, 117 insertions(+), 73 deletions(-) diff --git a/block/blk-zoned.c b/block/blk-zoned.c index d4fc87b0be6b..f62862274f9a 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -114,6 +114,33 @@ const char *blk_zone_cond_str(enum blk_zone_cond zone_cond) } EXPORT_SYMBOL_GPL(blk_zone_cond_str); +/** + * bdev_zone_is_seq - check if a sector belongs to a sequential write zone + * @bdev: block device to check + * @sector: sector number + * + * Check if @sector on @bdev is contained in a sequential write required zone. + */ +bool bdev_zone_is_seq(struct block_device *bdev, sector_t sector) +{ + struct gendisk *disk = bdev->bd_disk; + unsigned int zno = disk_zone_no(disk, sector); + bool is_seq = false; + u8 *zones_cond; + + if (!bdev_is_zoned(bdev)) + return false; + + rcu_read_lock(); + zones_cond = rcu_dereference(disk->zones_cond); + if (zones_cond && zno < disk->nr_zones) + is_seq = zones_cond[zno] != BLK_ZONE_COND_NOT_WP; + rcu_read_unlock(); + + return is_seq; +} +EXPORT_SYMBOL_GPL(bdev_zone_is_seq); + /* * Zone report arguments for block device drivers report_zones operation. * @cb: report_zones_cb callback for each reported zone. @@ -1458,22 +1485,16 @@ static void disk_destroy_zone_wplugs_hash_table(struct gendisk *disk) disk->zone_wplugs_hash_bits = 0; } -static unsigned int disk_set_conv_zones_bitmap(struct gendisk *disk, - unsigned long *bitmap) +static void disk_set_zones_cond_array(struct gendisk *disk, u8 *zones_cond) { - unsigned int nr_conv_zones = 0; unsigned long flags; spin_lock_irqsave(&disk->zone_wplugs_lock, flags); - if (bitmap) - nr_conv_zones = bitmap_weight(bitmap, disk->nr_zones); - bitmap = rcu_replace_pointer(disk->conv_zones_bitmap, bitmap, - lockdep_is_held(&disk->zone_wplugs_lock)); + zones_cond = rcu_replace_pointer(disk->zones_cond, zones_cond, + lockdep_is_held(&disk->zone_wplugs_lock)); spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags); - kfree_rcu_mightsleep(bitmap); - - return nr_conv_zones; + kfree_rcu_mightsleep(zones_cond); } void disk_free_zone_resources(struct gendisk *disk) @@ -1497,7 +1518,7 @@ void disk_free_zone_resources(struct gendisk *disk) mempool_destroy(disk->zone_wplugs_pool); disk->zone_wplugs_pool = NULL; - disk_set_conv_zones_bitmap(disk, NULL); + disk_set_zones_cond_array(disk, NULL); disk->zone_capacity = 0; disk->last_zone_capacity = 0; disk->nr_zones = 0; @@ -1516,12 +1537,31 @@ static inline bool disk_need_zone_resources(struct gendisk *disk) queue_emulates_zone_append(disk->queue); } +struct blk_revalidate_zone_args { + struct gendisk *disk; + u8 *zones_cond; + unsigned int nr_zones; + unsigned int nr_conv_zones; + unsigned int zone_capacity; + unsigned int last_zone_capacity; + sector_t sector; +}; + static int disk_revalidate_zone_resources(struct gendisk *disk, - unsigned int nr_zones) + struct blk_revalidate_zone_args *args) { struct queue_limits *lim = &disk->queue->limits; unsigned int pool_size; + args->disk = disk; + args->nr_zones = + DIV_ROUND_UP_ULL(get_capacity(disk), lim->chunk_sectors); + + /* Cached zone conditions: 1 byte per zone */ + args->zones_cond = kzalloc(args->nr_zones, GFP_NOIO); + if (!args->zones_cond) + return -ENOMEM; + if (!disk_need_zone_resources(disk)) return 0; @@ -1531,7 +1571,8 @@ static int disk_revalidate_zone_resources(struct gendisk *disk, */ pool_size = max(lim->max_open_zones, lim->max_active_zones); if (!pool_size) - pool_size = min(BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE, nr_zones); + pool_size = + min(BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE, args->nr_zones); if (!disk->zone_wplugs_hash) return disk_alloc_zone_resources(disk, pool_size); @@ -1539,15 +1580,6 @@ static int disk_revalidate_zone_resources(struct gendisk *disk, return 0; } -struct blk_revalidate_zone_args { - struct gendisk *disk; - unsigned long *conv_zones_bitmap; - unsigned int nr_zones; - unsigned int zone_capacity; - unsigned int last_zone_capacity; - sector_t sector; -}; - /* * Update the disk zone resources information and device queue limits. * The disk queue is frozen when this is executed. @@ -1556,7 +1588,7 @@ static int disk_update_zone_resources(struct gendisk *disk, struct blk_revalidate_zone_args *args) { struct request_queue *q = disk->queue; - unsigned int nr_seq_zones, nr_conv_zones; + unsigned int nr_seq_zones; unsigned int pool_size, memflags; struct queue_limits lim; int ret = 0; @@ -1566,24 +1598,24 @@ static int disk_update_zone_resources(struct gendisk *disk, memflags = blk_mq_freeze_queue(q); disk->nr_zones = args->nr_zones; - disk->zone_capacity = args->zone_capacity; - disk->last_zone_capacity = args->last_zone_capacity; - nr_conv_zones = - disk_set_conv_zones_bitmap(disk, args->conv_zones_bitmap); - if (nr_conv_zones >= disk->nr_zones) { + if (args->nr_conv_zones >= disk->nr_zones) { pr_warn("%s: Invalid number of conventional zones %u / %u\n", - disk->disk_name, nr_conv_zones, disk->nr_zones); + disk->disk_name, args->nr_conv_zones, disk->nr_zones); ret = -ENODEV; goto unfreeze; } + disk->zone_capacity = args->zone_capacity; + disk->last_zone_capacity = args->last_zone_capacity; + disk_set_zones_cond_array(disk, args->zones_cond); + /* - * Some devices can advertize zone resource limits that are larger than + * Some devices can advertise zone resource limits that are larger than * the number of sequential zones of the zoned block device, e.g. a * small ZNS namespace. For such case, assume that the zoned device has * no zone resource limits. */ - nr_seq_zones = disk->nr_zones - nr_conv_zones; + nr_seq_zones = disk->nr_zones - args->nr_conv_zones; if (lim.max_open_zones >= nr_seq_zones) lim.max_open_zones = 0; if (lim.max_active_zones >= nr_seq_zones) @@ -1624,6 +1656,44 @@ static int disk_update_zone_resources(struct gendisk *disk, return ret; } +static int blk_revalidate_zone_cond(struct blk_zone *zone, unsigned int idx, + struct blk_revalidate_zone_args *args) +{ + enum blk_zone_cond cond = zone->cond; + + /* Check that the zone condition is consistent with the zone type. */ + switch (cond) { + case BLK_ZONE_COND_NOT_WP: + if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) + goto invalid_condition; + break; + case BLK_ZONE_COND_IMP_OPEN: + case BLK_ZONE_COND_EXP_OPEN: + case BLK_ZONE_COND_CLOSED: + case BLK_ZONE_COND_EMPTY: + case BLK_ZONE_COND_FULL: + case BLK_ZONE_COND_OFFLINE: + case BLK_ZONE_COND_READONLY: + if (zone->type != BLK_ZONE_TYPE_SEQWRITE_REQ) + goto invalid_condition; + break; + default: + pr_warn("%s: Invalid zone condition 0x%X\n", + args->disk->disk_name, cond); + return -ENODEV; + } + + args->zones_cond[idx] = cond; + + return 0; + +invalid_condition: + pr_warn("%s: Invalid zone condition 0x%x for type 0x%x\n", + args->disk->disk_name, cond, zone->type); + + return -ENODEV; +} + static int blk_revalidate_conv_zone(struct blk_zone *zone, unsigned int idx, struct blk_revalidate_zone_args *args) { @@ -1638,17 +1708,7 @@ static int blk_revalidate_conv_zone(struct blk_zone *zone, unsigned int idx, if (disk_zone_is_last(disk, zone)) args->last_zone_capacity = zone->capacity; - if (!disk_need_zone_resources(disk)) - return 0; - - if (!args->conv_zones_bitmap) { - args->conv_zones_bitmap = - bitmap_zalloc(args->nr_zones, GFP_NOIO); - if (!args->conv_zones_bitmap) - return -ENOMEM; - } - - set_bit(idx, args->conv_zones_bitmap); + args->nr_conv_zones++; return 0; } @@ -1746,6 +1806,11 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx, return -ENODEV; } + /* Check zone condition */ + ret = blk_revalidate_zone_cond(zone, idx, args); + if (ret) + return ret; + /* Check zone type */ switch (zone->type) { case BLK_ZONE_TYPE_CONVENTIONAL: @@ -1813,10 +1878,8 @@ int blk_revalidate_disk_zones(struct gendisk *disk) * Ensure that all memory allocations in this context are done as if * GFP_NOIO was specified. */ - args.disk = disk; - args.nr_zones = (capacity + zone_sectors - 1) >> ilog2(zone_sectors); noio_flag = memalloc_noio_save(); - ret = disk_revalidate_zone_resources(disk, args.nr_zones); + ret = disk_revalidate_zone_resources(disk, &args); if (ret) { memalloc_noio_restore(noio_flag); return ret; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 2f75fb15f55f..53bcfbc2f68f 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -196,7 +196,7 @@ struct gendisk { unsigned int nr_zones; unsigned int zone_capacity; unsigned int last_zone_capacity; - unsigned long __rcu *conv_zones_bitmap; + u8 __rcu *zones_cond; unsigned int zone_wplugs_hash_bits; atomic_t nr_zone_wplugs; spinlock_t zone_wplugs_lock; @@ -925,12 +925,20 @@ static inline unsigned int bdev_zone_capacity(struct block_device *bdev, { return disk_zone_capacity(bdev->bd_disk, pos); } + +bool bdev_zone_is_seq(struct block_device *bdev, sector_t sector); + #else /* CONFIG_BLK_DEV_ZONED */ static inline unsigned int disk_nr_zones(struct gendisk *disk) { return 0; } +static inline bool bdev_zone_is_seq(struct block_device *bdev, sector_t sector) +{ + return false; +} + static inline bool bio_needs_zone_write_plugging(struct bio *bio) { return false; @@ -1533,33 +1541,6 @@ static inline bool bdev_is_zone_aligned(struct block_device *bdev, return bdev_is_zone_start(bdev, sector); } -/** - * bdev_zone_is_seq - check if a sector belongs to a sequential write zone - * @bdev: block device to check - * @sector: sector number - * - * Check if @sector on @bdev is contained in a sequential write required zone. - */ -static inline bool bdev_zone_is_seq(struct block_device *bdev, sector_t sector) -{ - bool is_seq = false; - -#if IS_ENABLED(CONFIG_BLK_DEV_ZONED) - if (bdev_is_zoned(bdev)) { - struct gendisk *disk = bdev->bd_disk; - unsigned long *bitmap; - - rcu_read_lock(); - bitmap = rcu_dereference(disk->conv_zones_bitmap); - is_seq = !bitmap || - !test_bit(disk_zone_no(disk, sector), bitmap); - rcu_read_unlock(); - } -#endif - - return is_seq; -} - int blk_zone_issue_zeroout(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask); -- 2.51.0
