diff options
Diffstat (limited to 'block/blk-zoned.c')
| -rw-r--r-- | block/blk-zoned.c | 1091 |
1 files changed, 1088 insertions, 3 deletions
diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 23d9bb21c459..fefcebd70445 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -7,6 +7,7 @@ * * Copyright (c) 2016, Damien Le Moal * Copyright (c) 2016, Western Digital + * Copyright (c) 2024, Western Digital Corporation or its affiliates. */ #include <linux/kernel.h> @@ -16,8 +17,12 @@ #include <linux/mm.h> #include <linux/vmalloc.h> #include <linux/sched/mm.h> +#include <linux/spinlock.h> +#include <linux/atomic.h> +#include <linux/mempool.h> #include "blk.h" +#include "blk-mq-sched.h" #define ZONE_COND_NAME(name) [BLK_ZONE_COND_##name] = #name static const char *const zone_cond_name[] = { @@ -32,6 +37,64 @@ static const char *const zone_cond_name[] = { }; #undef ZONE_COND_NAME +/* + * Per-zone write plug. + * @node: hlist_node structure for managing the plug using a hash table. + * @link: To list the plug in the zone write plug error list of the disk. + * @ref: Zone write plug reference counter. A zone write plug reference is + * always at least 1 when the plug is hashed in the disk plug hash table. + * The reference is incremented whenever a new BIO needing plugging is + * submitted and when a function needs to manipulate a plug. The + * reference count is decremented whenever a plugged BIO completes and + * when a function that referenced the plug returns. The initial + * reference is dropped whenever the zone of the zone write plug is reset, + * finished and when the zone becomes full (last write BIO to the zone + * completes). + * @lock: Spinlock to atomically manipulate the plug. + * @flags: Flags indicating the plug state. + * @zone_no: The number of the zone the plug is managing. + * @wp_offset: The zone write pointer location relative to the start of the zone + * as a number of 512B sectors. + * @bio_list: The list of BIOs that are currently plugged. + * @bio_work: Work struct to handle issuing of plugged BIOs + * @rcu_head: RCU head to free zone write plugs with an RCU grace period. + * @disk: The gendisk the plug belongs to. + */ +struct blk_zone_wplug { + struct hlist_node node; + struct list_head link; + atomic_t ref; + spinlock_t lock; + unsigned int flags; + unsigned int zone_no; + unsigned int wp_offset; + struct bio_list bio_list; + struct work_struct bio_work; + struct rcu_head rcu_head; + struct gendisk *disk; +}; + +/* + * Zone write plug flags bits: + * - BLK_ZONE_WPLUG_PLUGGED: Indicates that the zone write plug is plugged, + * that is, that write BIOs are being throttled due to a write BIO already + * being executed or the zone write plug bio list is not empty. + * - BLK_ZONE_WPLUG_ERROR: Indicates that a write error happened which will be + * recovered with a report zone to update the zone write pointer offset. + * - BLK_ZONE_WPLUG_UNHASHED: Indicates that the zone write plug was removed + * from the disk hash table and that the initial reference to the zone + * write plug set when the plug was first added to the hash table has been + * dropped. This flag is set when a zone is reset, finished or become full, + * to prevent new references to the zone write plug to be taken for + * newly incoming BIOs. A zone write plug flagged with this flag will be + * freed once all remaining references from BIOs or functions are dropped. + */ +#define BLK_ZONE_WPLUG_PLUGGED (1U << 0) +#define BLK_ZONE_WPLUG_ERROR (1U << 1) +#define BLK_ZONE_WPLUG_UNHASHED (1U << 2) + +#define BLK_ZONE_WPLUG_BUSY (BLK_ZONE_WPLUG_PLUGGED | BLK_ZONE_WPLUG_ERROR) + /** * blk_zone_cond_str - Return string XXX in BLK_ZONE_COND_XXX. * @zone_cond: BLK_ZONE_COND_XXX. @@ -425,12 +488,1010 @@ fail: return ret; } -void disk_free_zone_bitmaps(struct gendisk *disk) +static inline bool disk_zone_is_conv(struct gendisk *disk, sector_t sector) +{ + if (!disk->conv_zones_bitmap) + return false; + return test_bit(disk_zone_no(disk, sector), disk->conv_zones_bitmap); +} + +static bool disk_insert_zone_wplug(struct gendisk *disk, + struct blk_zone_wplug *zwplug) +{ + struct blk_zone_wplug *zwplg; + unsigned long flags; + unsigned int idx = + hash_32(zwplug->zone_no, disk->zone_wplugs_hash_bits); + + /* + * Add the new zone write plug to the hash table, but carefully as we + * are racing with other submission context, so we may already have a + * zone write plug for the same zone. + */ + spin_lock_irqsave(&disk->zone_wplugs_lock, flags); + hlist_for_each_entry_rcu(zwplg, &disk->zone_wplugs_hash[idx], node) { + if (zwplg->zone_no == zwplug->zone_no) { + spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags); + return false; + } + } + hlist_add_head_rcu(&zwplug->node, &disk->zone_wplugs_hash[idx]); + spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags); + + return true; +} + +static void disk_remove_zone_wplug(struct gendisk *disk, + struct blk_zone_wplug *zwplug) +{ + unsigned long flags; + + spin_lock_irqsave(&disk->zone_wplugs_lock, flags); + zwplug->flags |= BLK_ZONE_WPLUG_UNHASHED; + atomic_dec(&zwplug->ref); + hlist_del_init_rcu(&zwplug->node); + spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags); +} + +static inline bool disk_should_remove_zone_wplug(struct gendisk *disk, + struct blk_zone_wplug *zwplug) +{ + /* If the zone is still busy, the plug cannot be removed. */ + if (zwplug->flags & BLK_ZONE_WPLUG_BUSY) + return false; + + /* We can remove zone write plugs for zones that are empty or full. */ + return !zwplug->wp_offset || zwplug->wp_offset >= disk->zone_capacity; +} + +static struct blk_zone_wplug *disk_get_zone_wplug(struct gendisk *disk, + sector_t sector) +{ + unsigned int zno = disk_zone_no(disk, sector); + unsigned int idx = hash_32(zno, disk->zone_wplugs_hash_bits); + struct blk_zone_wplug *zwplug; + + rcu_read_lock(); + + hlist_for_each_entry_rcu(zwplug, &disk->zone_wplugs_hash[idx], node) { + if (zwplug->zone_no == zno && + atomic_inc_not_zero(&zwplug->ref)) { + rcu_read_unlock(); + return zwplug; + } + } + + rcu_read_unlock(); + + return NULL; +} + +static void disk_free_zone_wplug_rcu(struct rcu_head *rcu_head) +{ + struct blk_zone_wplug *zwplug = + container_of(rcu_head, struct blk_zone_wplug, rcu_head); + + mempool_free(zwplug, zwplug->disk->zone_wplugs_pool); +} + +static inline void disk_put_zone_wplug(struct blk_zone_wplug *zwplug) +{ + if (atomic_dec_and_test(&zwplug->ref)) { + WARN_ON_ONCE(!bio_list_empty(&zwplug->bio_list)); + WARN_ON_ONCE(!list_empty(&zwplug->link)); + + call_rcu(&zwplug->rcu_head, disk_free_zone_wplug_rcu); + } +} + +static void blk_zone_wplug_bio_work(struct work_struct *work); + +/* + * Get a reference on the write plug for the zone containing @sector. + * If the plug does not exist, it is allocated and hashed. + * Return a pointer to the zone write plug with the plug spinlock held. + */ +static struct blk_zone_wplug *disk_get_and_lock_zone_wplug(struct gendisk *disk, + sector_t sector, gfp_t gfp_mask, + unsigned long *flags) { + unsigned int zno = disk_zone_no(disk, sector); + struct blk_zone_wplug *zwplug; + +again: + zwplug = disk_get_zone_wplug(disk, sector); + if (zwplug) { + /* + * Check that a BIO completion or a zone reset or finish + * operation has not already removed the zone write plug from + * the hash table and dropped its reference count. In such case, + * we need to get a new plug so start over from the beginning. + */ + spin_lock_irqsave(&zwplug->lock, *flags); + if (zwplug->flags & BLK_ZONE_WPLUG_UNHASHED) { + spin_unlock_irqrestore(&zwplug->lock, *flags); + disk_put_zone_wplug(zwplug); + goto again; + } + return zwplug; + } + + /* + * Allocate and initialize a zone write plug with an extra reference + * so that it is not freed when the zone write plug becomes idle without + * the zone being full. + */ + zwplug = mempool_alloc(disk->zone_wplugs_pool, gfp_mask); + if (!zwplug) + return NULL; + + INIT_HLIST_NODE(&zwplug->node); + INIT_LIST_HEAD(&zwplug->link); + atomic_set(&zwplug->ref, 2); + spin_lock_init(&zwplug->lock); + zwplug->flags = 0; + zwplug->zone_no = zno; + zwplug->wp_offset = sector & (disk->queue->limits.chunk_sectors - 1); + bio_list_init(&zwplug->bio_list); + INIT_WORK(&zwplug->bio_work, blk_zone_wplug_bio_work); + zwplug->disk = disk; + + spin_lock_irqsave(&zwplug->lock, *flags); + + /* + * Insert the new zone write plug in the hash table. This can fail only + * if another context already inserted a plug. Retry from the beginning + * in such case. + */ + if (!disk_insert_zone_wplug(disk, zwplug)) { + spin_unlock_irqrestore(&zwplug->lock, *flags); + mempool_free(zwplug, disk->zone_wplugs_pool); + goto again; + } + + return zwplug; +} + +static inline void blk_zone_wplug_bio_io_error(struct bio *bio) +{ + struct request_queue *q = bio->bi_bdev->bd_disk->queue; + + bio_clear_flag(bio, BIO_ZONE_WRITE_PLUGGING); + bio_io_error(bio); + blk_queue_exit(q); +} + +/* + * Abort (fail) all plugged BIOs of a zone write plug. + */ +static void disk_zone_wplug_abort(struct blk_zone_wplug *zwplug) +{ + struct bio *bio; + + while ((bio = bio_list_pop(&zwplug->bio_list))) { + blk_zone_wplug_bio_io_error(bio); + disk_put_zone_wplug(zwplug); + } +} + +/* + * Abort (fail) all plugged BIOs of a zone write plug that are not aligned + * with the assumed write pointer location of the zone when the BIO will + * be unplugged. + */ +static void disk_zone_wplug_abort_unaligned(struct gendisk *disk, + struct blk_zone_wplug *zwplug) +{ + unsigned int zone_capacity = disk->zone_capacity; + unsigned int wp_offset = zwplug->wp_offset; + struct bio_list bl = BIO_EMPTY_LIST; + struct bio *bio; + + while ((bio = bio_list_pop(&zwplug->bio_list))) { + if (wp_offset >= zone_capacity || + bio_offset_from_zone_start(bio) != wp_offset) { + blk_zone_wplug_bio_io_error(bio); + disk_put_zone_wplug(zwplug); + continue; + } + + wp_offset += bio_sectors(bio); + bio_list_add(&bl, bio); + } + + bio_list_merge(&zwplug->bio_list, &bl); +} + +/* + * Set a zone write plug write pointer offset to either 0 (zone reset case) + * or to the zone size (zone finish case). This aborts all plugged BIOs, which + * is fine to do as doing a zone reset or zone finish while writes are in-flight + * is a mistake from the user which will most likely cause all plugged BIOs to + * fail anyway. + */ +static void disk_zone_wplug_set_wp_offset(struct gendisk *disk, + struct blk_zone_wplug *zwplug, + unsigned int wp_offset) +{ + unsigned long flags; + + spin_lock_irqsave(&zwplug->lock, flags); + + /* + * Make sure that a BIO completion or another zone reset or finish + * operation has not already removed the plug from the hash table. + */ + if (zwplug->flags & BLK_ZONE_WPLUG_UNHASHED) { + spin_unlock_irqrestore(&zwplug->lock, flags); + return; + } + + /* Update the zone write pointer and abort all plugged BIOs. */ + zwplug->wp_offset = wp_offset; + disk_zone_wplug_abort(zwplug); + + /* + * Updating the write pointer offset puts back the zone + * in a good state. So clear the error flag and decrement the + * error count if we were in error state. + */ + if (zwplug->flags & BLK_ZONE_WPLUG_ERROR) { + zwplug->flags &= ~BLK_ZONE_WPLUG_ERROR; + spin_lock(&disk->zone_wplugs_lock); + list_del_init(&zwplug->link); + spin_unlock(&disk->zone_wplugs_lock); + } + + /* + * The zone write plug now has no BIO plugged: remove it from the + * hash table so that it cannot be seen. The plug will be freed + * when the last reference is dropped. + */ + if (disk_should_remove_zone_wplug(disk, zwplug)) + disk_remove_zone_wplug(disk, zwplug); + + spin_unlock_irqrestore(&zwplug->lock, flags); +} + +static bool blk_zone_wplug_handle_reset_or_finish(struct bio *bio, + unsigned int wp_offset) +{ + struct gendisk *disk = bio->bi_bdev->bd_disk; + sector_t sector = bio->bi_iter.bi_sector; + struct blk_zone_wplug *zwplug; + + /* Conventional zones cannot be reset nor finished. */ + if (disk_zone_is_conv(disk, sector)) { + bio_io_error(bio); + return true; + } + + /* + * If we have a zone write plug, set its write pointer offset to 0 + * (reset case) or to the zone size (finish case). This will abort all + * BIOs plugged for the target zone. It is fine as resetting or + * finishing zones while writes are still in-flight will result in the + * writes failing anyway. + */ + zwplug = disk_get_zone_wplug(disk, sector); + if (zwplug) { + disk_zone_wplug_set_wp_offset(disk, zwplug, wp_offset); + disk_put_zone_wplug(zwplug); + } + + return false; +} + +static bool blk_zone_wplug_handle_reset_all(struct bio *bio) +{ + struct gendisk *disk = bio->bi_bdev->bd_disk; + struct blk_zone_wplug *zwplug; + sector_t sector; + + /* + * Set the write pointer offset of all zone write plugs to 0. This will + * abort all plugged BIOs. It is fine as resetting zones while writes + * are still in-flight will result in the writes failing anyway. + */ + for (sector = 0; sector < get_capacity(disk); + sector += disk->queue->limits.chunk_sectors) { + zwplug = disk_get_zone_wplug(disk, sector); + if (zwplug) { + disk_zone_wplug_set_wp_offset(disk, zwplug, 0); + disk_put_zone_wplug(zwplug); + } + } + + return false; +} + +static inline void blk_zone_wplug_add_bio(struct blk_zone_wplug *zwplug, + struct bio *bio, unsigned int nr_segs) +{ + /* + * Grab an extra reference on the BIO request queue usage counter. + * This reference will be reused to submit a request for the BIO for + * blk-mq devices and dropped when the BIO is failed and after + * it is issued in the case of BIO-based devices. + */ + percpu_ref_get(&bio->bi_bdev->bd_disk->queue->q_usage_counter); + + /* + * The BIO is being plugged and thus will have to wait for the on-going + * write and for all other writes already plugged. So polling makes + * no sense. + */ + bio_clear_polled(bio); + + /* + * Reuse the poll cookie field to store the number of segments when + * split to the hardware limits. + */ + bio->__bi_nr_segments = nr_segs; + + /* + * We always receive BIOs after they are split and ready to be issued. + * The block layer passes the parts of a split BIO in order, and the + * user must also issue write sequentially. So simply add the new BIO + * at the tail of the list to preserve the sequential write order. + */ + bio_list_add(&zwplug->bio_list, bio); +} + +/* + * Called from bio_attempt_back_merge() when a BIO was merged with a request. + */ +void blk_zone_write_plug_bio_merged(struct bio *bio) +{ + struct blk_zone_wplug *zwplug; + unsigned long flags; + + /* + * If the BIO was already plugged, then we were called through + * blk_zone_write_plug_attempt_merge() -> blk_attempt_bio_merge(). + * For this case, blk_zone_write_plug_attempt_merge() will handle the + * zone write pointer offset update. + */ + if (bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING)) + return; + + bio_set_flag(bio, BIO_ZONE_WRITE_PLUGGING); + + /* + * Increase the plug reference count and advance the zone write + * pointer offset. + */ + zwplug = disk_get_zone_wplug(bio->bi_bdev->bd_disk, + bio->bi_iter.bi_sector); + spin_lock_irqsave(&zwplug->lock, flags); + zwplug->wp_offset += bio_sectors(bio); + spin_unlock_irqrestore(&zwplug->lock, flags); +} + +/* + * Attempt to merge plugged BIOs with a newly prepared request for a BIO that + * already went through zone write plugging (either a new BIO or one that was + * unplugged). + */ +void blk_zone_write_plug_attempt_merge(struct request *req) +{ + sector_t req_back_sector = blk_rq_pos(req) + blk_rq_sectors(req); + struct request_queue *q = req->q; + struct gendisk *disk = q->disk; + unsigned int zone_capacity = disk->zone_capacity; + struct blk_zone_wplug *zwplug = + disk_get_zone_wplug(disk, blk_rq_pos(req)); + unsigned long flags; + struct bio *bio; + + /* + * Completion of this request needs to be handled with + * blk_zone_write_plug_complete_request(). + */ + req->rq_flags |= RQF_ZONE_WRITE_PLUGGING; + + if (blk_queue_nomerges(q)) + return; + + /* + * Walk through the list of plugged BIOs to check if they can be merged + * into the back of the request. + */ + spin_lock_irqsave(&zwplug->lock, flags); + while (zwplug->wp_offset < zone_capacity) { + bio = bio_list_peek(&zwplug->bio_list); + if (!bio) + break; + + if (bio->bi_iter.bi_sector != req_back_sector || + !blk_rq_merge_ok(req, bio)) + break; + + WARN_ON_ONCE(bio_op(bio) != REQ_OP_WRITE_ZEROES && + !bio->__bi_nr_segments); + + bio_list_pop(&zwplug->bio_list); + if (bio_attempt_back_merge(req, bio, bio->__bi_nr_segments) != + BIO_MERGE_OK) { + bio_list_add_head(&zwplug->bio_list, bio); + break; + } + + /* + * Drop the extra reference on the queue usage we got when + * plugging the BIO and advance the write pointer offset. + */ + blk_queue_exit(q); + zwplug->wp_offset += bio_sectors(bio); + + req_back_sector += bio_sectors(bio); + } + spin_unlock_irqrestore(&zwplug->lock, flags); +} + +static inline void disk_zone_wplug_set_error(struct gendisk *disk, + struct blk_zone_wplug *zwplug) +{ + if (!(zwplug->flags & BLK_ZONE_WPLUG_ERROR)) { + unsigned long flags; + + /* + * Increase the plug reference count. The reference will be + * dropped in disk_zone_wplugs_work() once the error state + * is handled. + */ + zwplug->flags |= BLK_ZONE_WPLUG_ERROR; + atomic_inc(&zwplug->ref); + + spin_lock_irqsave(&disk->zone_wplugs_lock, flags); + list_add_tail(&zwplug->link, &disk->zone_wplugs_err_list); + spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags); + } +} + +/* + * Check and prepare a BIO for submission by incrementing the write pointer + * offset of its zone write plug. + */ +static bool blk_zone_wplug_prepare_bio(struct blk_zone_wplug *zwplug, + struct bio *bio) +{ + struct gendisk *disk = bio->bi_bdev->bd_disk; + + /* + * Check that the user is not attempting to write to a full zone. + * We know such BIO will fail, and that would potentially overflow our + * write pointer offset beyond the end of the zone. + */ + if (zwplug->wp_offset >= disk->zone_capacity) + goto err; + + /* + * Check for non-sequential writes early because we avoid a + * whole lot of error handling trouble if we don't send it off + * to the driver. + */ + if (bio_offset_from_zone_start(bio) != zwplug->wp_offset) + goto err; + + /* Advance the zone write pointer offset. */ + zwplug->wp_offset += bio_sectors(bio); + + return true; + +err: + /* We detected an invalid write BIO: schedule error recovery. */ + disk_zone_wplug_set_error(disk, zwplug); + kblockd_schedule_work(&disk->zone_wplugs_work); + return false; +} + +static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs) +{ + struct gendisk *disk = bio->bi_bdev->bd_disk; + sector_t sector = bio->bi_iter.bi_sector; + struct blk_zone_wplug *zwplug; + gfp_t gfp_mask = GFP_NOIO; + unsigned long flags; + + /* + * BIOs must be fully contained within a zone so that we use the correct + * zone write plug for the entire BIO. For blk-mq devices, the block + * layer should already have done any splitting required to ensure this + * and this BIO should thus not be straddling zone boundaries. For + * BIO-based devices, it is the responsibility of the driver to split + * the bio before submitting it. + */ + if (WARN_ON_ONCE(bio_straddles_zones(bio))) { + bio_io_error(bio); + return true; + } + + /* Conventional zones do not need write plugging. */ + if (disk_zone_is_conv(disk, sector)) + return false; + + if (bio->bi_opf & REQ_NOWAIT) + gfp_mask = GFP_NOWAIT; + + zwplug = disk_get_and_lock_zone_wplug(disk, sector, gfp_mask, &flags); + if (!zwplug) { + bio_io_error(bio); + return true; + } + + /* Indicate that this BIO is being handled using zone write plugging. */ + bio_set_flag(bio, BIO_ZONE_WRITE_PLUGGING); + + /* + * If the zone is already plugged or has a pending error, add the BIO + * to the plug BIO list. Otherwise, plug and let the BIO execute. + */ + if (zwplug->flags & BLK_ZONE_WPLUG_BUSY) + goto plug; + + /* + * If an error is detected when preparing the BIO, add it to the BIO + * list so that error recovery can deal with it. + */ + if (!blk_zone_wplug_prepare_bio(zwplug, bio)) + goto plug; + + zwplug->flags |= BLK_ZONE_WPLUG_PLUGGED; + + spin_unlock_irqrestore(&zwplug->lock, flags); + + return false; + +plug: + zwplug->flags |= BLK_ZONE_WPLUG_PLUGGED; + blk_zone_wplug_add_bio(zwplug, bio, nr_segs); + + spin_unlock_irqrestore(&zwplug->lock, flags); + + return true; +} + +/** + * blk_zone_plug_bio - Handle a zone write BIO with zone write plugging + * @bio: The BIO being submitted + * @nr_segs: The number of physical segments of @bio + * + * Handle write and write zeroes operations using zone write plugging. + * + * Return true whenever @bio execution needs to be delayed through the zone + * write plug. Otherwise, return false to let the submission path process + * @bio normally. + */ +bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) +{ + struct block_device *bdev = bio->bi_bdev; + + if (!bdev->bd_disk->zone_wplugs_hash) + return false; + + /* + * If the BIO already has the plugging flag set, then it was already + * handled through this path and this is a submission from the zone + * plug bio submit work. + */ + if (bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING)) + return false; + + /* + * We do not need to do anything special for empty flush BIOs, e.g + * BIOs such as issued by blkdev_issue_flush(). The is because it is + * the responsibility of the user to first wait for the completion of + * write operations for flush to have any effect on the persistence of + * the written data. + */ + if (op_is_flush(bio->bi_opf) && !bio_sectors(bio)) + return false; + + /* + * Regular writes and write zeroes need to be handled through the target + * zone write plug. This includes writes with REQ_FUA | REQ_PREFLUSH + * which may need to go through the flush machinery depending on the + * target device capabilities. Plugging such writes is fine as the flush + * machinery operates at the request level, below the plug, and + * completion of the flush sequence will go through the regular BIO + * completion, which will handle zone write plugging. + * Zone reset, reset all and finish commands need special treatment + * to correctly track the write pointer offset of zones. These commands + * are not plugged as we do not need serialization with write + * operations. It is the responsibility of the user to not issue reset + * and finish commands when write operations are in flight. + */ + switch (bio_op(bio)) { + case REQ_OP_WRITE: + case REQ_OP_WRITE_ZEROES: + return blk_zone_wplug_handle_write(bio, nr_segs); + case REQ_OP_ZONE_RESET: + return blk_zone_wplug_handle_reset_or_finish(bio, 0); + case REQ_OP_ZONE_FINISH: + return blk_zone_wplug_handle_reset_or_finish(bio, + bdev_zone_sectors(bdev)); + case REQ_OP_ZONE_RESET_ALL: + return blk_zone_wplug_handle_reset_all(bio); + default: + return false; + } + + return false; +} +EXPORT_SYMBOL_GPL(blk_zone_plug_bio); + +static void disk_zone_wplug_unplug_bio(struct gendisk *disk, + struct blk_zone_wplug *zwplug) +{ + unsigned long flags; + + spin_lock_irqsave(&zwplug->lock, flags); + + /* + * If we had an error, schedule error recovery. The recovery work + * will restart submission of plugged BIOs. + */ + if (zwplug->flags & BLK_ZONE_WPLUG_ERROR) { + spin_unlock_irqrestore(&zwplug->lock, flags); + kblockd_schedule_work(&disk->zone_wplugs_work); + return; + } + + /* Schedule submission of the next plugged BIO if we have one. */ + if (!bio_list_empty(&zwplug->bio_list)) { + spin_unlock_irqrestore(&zwplug->lock, flags); + kblockd_schedule_work(&zwplug->bio_work); + return; + } + + zwplug->flags &= ~BLK_ZONE_WPLUG_PLUGGED; + + /* + * If the zone is full (it was fully written or finished, or empty + * (it was reset), remove its zone write plug from the hash table. + */ + if (disk_should_remove_zone_wplug(disk, zwplug)) + disk_remove_zone_wplug(disk, zwplug); + + spin_unlock_irqrestore(&zwplug->lock, flags); +} + +void blk_zone_write_plug_bio_endio(struct bio *bio) +{ + struct gendisk *disk = bio->bi_bdev->bd_disk; + struct blk_zone_wplug *zwplug = + disk_get_zone_wplug(bio->bi_bdev->bd_disk, + bio->bi_iter.bi_sector); + unsigned long flags; + + if (WARN_ON_ONCE(!zwplug)) + return; + + /* Make sure we do not see this BIO again by clearing the plug flag. */ + bio_clear_flag(bio, BIO_ZONE_WRITE_PLUGGING); + + /* + * If the BIO failed, mark the plug as having an error to trigger + * recovery. + */ + if (bio->bi_status != BLK_STS_OK) { + spin_lock_irqsave(&zwplug->lock, flags); + disk_zone_wplug_set_error(disk, zwplug); + spin_unlock_irqrestore(&zwplug->lock, flags); + } + + /* + * For BIO-based devices, blk_zone_write_plug_complete_request() + * is not called. So we need to schedule execution of the next + * plugged BIO here. + */ + if (bio->bi_bdev->bd_has_submit_bio) + disk_zone_wplug_unplug_bio(disk, zwplug); + + /* Drop the reference we took when the BIO was issued. */ + atomic_dec(&zwplug->ref); + disk_put_zone_wplug(zwplug); +} + +void blk_zone_write_plug_complete_request(struct request *req) +{ + struct gendisk *disk = req->q->disk; + struct blk_zone_wplug *zwplug = disk_get_zone_wplug(disk, req->__sector); + + if (WARN_ON_ONCE(!zwplug)) + return; + + req->rq_flags &= ~RQF_ZONE_WRITE_PLUGGING; + + disk_zone_wplug_unplug_bio(disk, zwplug); + + /* + * Drop the reference we took when the request was initialized in + * blk_zone_write_plug_attempt_merge(). + */ + atomic_dec(&zwplug->ref); + disk_put_zone_wplug(zwplug); +} + +static void blk_zone_wplug_bio_work(struct work_struct *work) +{ + struct blk_zone_wplug *zwplug = + container_of(work, struct blk_zone_wplug, bio_work); + struct block_device *bdev; + unsigned long flags; + struct bio *bio; + + /* + * Submit the next plugged BIO. If we do not have any, clear + * the plugged flag. + */ + spin_lock_irqsave(&zwplug->lock, flags); + + bio = bio_list_pop(&zwplug->bio_list); + if (!bio) { + zwplug->flags &= ~BLK_ZONE_WPLUG_PLUGGED; + spin_unlock_irqrestore(&zwplug->lock, flags); + return; + } + + if (!blk_zone_wplug_prepare_bio(zwplug, bio)) { + /* Error recovery will decide what to do with the BIO. */ + bio_list_add_head(&zwplug->bio_list, bio); + spin_unlock_irqrestore(&zwplug->lock, flags); + return; + } + + spin_unlock_irqrestore(&zwplug->lock, flags); + + bdev = bio->bi_bdev; + submit_bio_noacct_nocheck(bio); + + /* + * blk-mq devices will reuse the extra reference on the request queue + * usage counter we took when the BIO was plugged, but the submission + * path for BIO-based devices will not do that. So drop this extra + * reference here. + */ + if (bdev->bd_has_submit_bio) + blk_queue_exit(bdev->bd_disk->queue); +} + +static unsigned int blk_zone_wp_offset(struct blk_zone *zone) +{ + switch (zone->cond) { + case BLK_ZONE_COND_IMP_OPEN: + case BLK_ZONE_COND_EXP_OPEN: + case BLK_ZONE_COND_CLOSED: + return zone->wp - zone->start; + case BLK_ZONE_COND_FULL: + return zone->len; + case BLK_ZONE_COND_EMPTY: + return 0; + case BLK_ZONE_COND_NOT_WP: + case BLK_ZONE_COND_OFFLINE: + case BLK_ZONE_COND_READONLY: + default: + /* + * Conventional, offline and read-only zones do not have a valid + * write pointer. + */ + return UINT_MAX; + } +} + +static int blk_zone_wplug_report_zone_cb(struct blk_zone *zone, + unsigned int idx, void *data) +{ + struct blk_zone *zonep = data; + + *zonep = *zone; + return 0; +} + +static void disk_zone_wplug_handle_error(struct gendisk *disk, + struct blk_zone_wplug *zwplug) +{ + sector_t zone_start_sector = + bdev_zone_sectors(disk->part0) * zwplug->zone_no; + unsigned int noio_flag; + struct blk_zone zone; + unsigned long flags; + int ret; + + /* Get the current zone information from the device. */ + noio_flag = memalloc_noio_save(); + ret = disk->fops->report_zones(disk, zone_start_sector, 1, + blk_zone_wplug_report_zone_cb, &zone); + memalloc_noio_restore(noio_flag); + + spin_lock_irqsave(&zwplug->lock, flags); + + /* + * A zone reset or finish may have cleared the error already. In such + * case, do nothing as the report zones may have seen the "old" write + * pointer value before the reset/finish operation completed. + */ + if (!(zwplug->flags & BLK_ZONE_WPLUG_ERROR)) + goto unlock; + + zwplug->flags &= ~BLK_ZONE_WPLUG_ERROR; + + if (ret != 1) { + /* + * We failed to get the zone information, meaning that something + * is likely really wrong with the device. Abort all remaining + * plugged BIOs as otherwise we could endup waiting forever on + * plugged BIOs to complete if there is a queue freeze on-going. + */ + disk_zone_wplug_abort(zwplug); + goto unplug; + } + + /* Update the zone write pointer offset. */ + zwplug->wp_offset = blk_zone_wp_offset(&zone); + disk_zone_wplug_abort_unaligned(disk, zwplug); + + /* Restart BIO submission if we still have any BIO left. */ + if (!bio_list_empty(&zwplug->bio_list)) { + WARN_ON_ONCE(!(zwplug->flags & BLK_ZONE_WPLUG_PLUGGED)); + kblockd_schedule_work(&zwplug->bio_work); + goto unlock; + } + +unplug: + zwplug->flags &= ~BLK_ZONE_WPLUG_PLUGGED; + if (disk_should_remove_zone_wplug(disk, zwplug)) + disk_remove_zone_wplug(disk, zwplug); + +unlock: + spin_unlock_irqrestore(&zwplug->lock, flags); +} + +static void disk_zone_wplugs_work(struct work_struct *work) +{ + struct gendisk *disk = + container_of(work, struct gendisk, zone_wplugs_work); + struct blk_zone_wplug *zwplug; + unsigned long flags; + + spin_lock_irqsave(&disk->zone_wplugs_lock, flags); + + while (!list_empty(&disk->zone_wplugs_err_list)) { + zwplug = list_first_entry(&disk->zone_wplugs_err_list, + struct blk_zone_wplug, link); + list_del_init(&zwplug->link); + spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags); + + disk_zone_wplug_handle_error(disk, zwplug); + disk_put_zone_wplug(zwplug); + + spin_lock_irqsave(&disk->zone_wplugs_lock, flags); + } + + spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags); +} + +static inline unsigned int disk_zone_wplugs_hash_size(struct gendisk *disk) +{ + return 1U << disk->zone_wplugs_hash_bits; +} + +void disk_init_zone_resources(struct gendisk *disk) +{ + spin_lock_init(&disk->zone_wplugs_lock); + INIT_LIST_HEAD(&disk->zone_wplugs_err_list); + INIT_WORK(&disk->zone_wplugs_work, disk_zone_wplugs_work); +} + +/* + * For the size of a disk zone write plug hash table, use the size of the + * zone write plug mempool, which is the maximum of the disk open zones and + * active zones limits. But do not exceed 4KB (512 hlist head entries), that is, + * 9 bits. For a disk that has no limits, mempool size defaults to 128. + */ +#define BLK_ZONE_WPLUG_MAX_HASH_BITS 9 +#define BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE 128 + +static int disk_alloc_zone_resources(struct gendisk *disk, + unsigned int pool_size) +{ + unsigned int i; + + disk->zone_wplugs_hash_bits = + min(ilog2(pool_size) + 1, BLK_ZONE_WPLUG_MAX_HASH_BITS); + + disk->zone_wplugs_hash = + kcalloc(disk_zone_wplugs_hash_size(disk), + sizeof(struct hlist_head), GFP_KERNEL); + if (!disk->zone_wplugs_hash) + return -ENOMEM; + + for (i = 0; i < disk_zone_wplugs_hash_size(disk); i++) + INIT_HLIST_HEAD(&disk->zone_wplugs_hash[i]); + + disk->zone_wplugs_pool = mempool_create_kmalloc_pool(pool_size, + sizeof(struct blk_zone_wplug)); + if (!disk->zone_wplugs_pool) { + kfree(disk->zone_wplugs_hash); + disk->zone_wplugs_hash = NULL; + disk->zone_wplugs_hash_bits = 0; + return -ENOMEM; + } + + return 0; +} + +static void disk_destroy_zone_wplugs_hash_table(struct gendisk *disk) +{ + struct blk_zone_wplug *zwplug; + unsigned int i; + + if (!disk->zone_wplugs_hash) + return; + + /* Free all the zone write plugs we have. */ + for (i = 0; i < disk_zone_wplugs_hash_size(disk); i++) { + while (!hlist_empty(&disk->zone_wplugs_hash[i])) { + zwplug = hlist_entry(disk->zone_wplugs_hash[i].first, + struct blk_zone_wplug, node); + atomic_inc(&zwplug->ref); + disk_remove_zone_wplug(disk, zwplug); + disk_put_zone_wplug(zwplug); + } + } + + kfree(disk->zone_wplugs_hash); + disk->zone_wplugs_hash = NULL; + disk->zone_wplugs_hash_bits = 0; +} + +void disk_free_zone_resources(struct gendisk *disk) +{ + cancel_work_sync(&disk->zone_wplugs_work); + + disk_destroy_zone_wplugs_hash_table(disk); + + /* + * Wait for the zone write plugs to be RCU-freed before + * destorying the mempool. + */ + rcu_barrier(); + + mempool_destroy(disk->zone_wplugs_pool); + disk->zone_wplugs_pool = NULL; + kfree(disk->conv_zones_bitmap); disk->conv_zones_bitmap = NULL; kfree(disk->seq_zones_wlock); disk->seq_zones_wlock = NULL; + + disk->zone_capacity = 0; + disk->nr_zones = 0; +} + +static int disk_revalidate_zone_resources(struct gendisk *disk, + unsigned int nr_zones) +{ + struct queue_limits *lim = &disk->queue->limits; + unsigned int pool_size; + + /* + * If the device has no limit on the maximum number of open and active + * zones, use BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE. + */ + 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); + + if (!disk->zone_wplugs_hash) + return disk_alloc_zone_resources(disk, pool_size); + + /* Resize the zone write plug memory pool if needed. */ + if (disk->zone_wplugs_pool->min_nr != pool_size) + return mempool_resize(disk->zone_wplugs_pool, pool_size); + + return 0; } struct blk_revalidate_zone_args { @@ -453,6 +1514,9 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx, struct request_queue *q = disk->queue; sector_t capacity = get_capacity(disk); sector_t zone_sectors = q->limits.chunk_sectors; + struct blk_zone_wplug *zwplug; + unsigned long flags; + unsigned int wp_offset; /* Check for bad zones and holes in the zone report */ if (zone->start != args->sector) { @@ -524,6 +1588,22 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx, disk->disk_name); return -ENODEV; } + + /* + * We need to track the write pointer of all zones that are not + * empty nor full. So make sure we have a zone write plug for + * such zone. + */ + wp_offset = blk_zone_wp_offset(zone); + if (wp_offset && wp_offset < zone_sectors) { + zwplug = disk_get_and_lock_zone_wplug(disk, zone->start, + GFP_NOIO, &flags); + if (!zwplug) + return -ENOMEM; + spin_unlock_irqrestore(&zwplug->lock, flags); + disk_put_zone_wplug(zwplug); + } + break; case BLK_ZONE_TYPE_SEQWRITE_PREF: default: @@ -560,7 +1640,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk, sector_t capacity = get_capacity(disk); struct blk_revalidate_zone_args args = { }; unsigned int noio_flag; - int ret; + int ret = -ENOMEM; if (WARN_ON_ONCE(!blk_queue_is_zoned(q))) return -EIO; @@ -593,6 +1673,11 @@ int blk_revalidate_disk_zones(struct gendisk *disk, 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); + if (ret) { + memalloc_noio_restore(noio_flag); + return ret; + } ret = disk->fops->report_zones(disk, 0, UINT_MAX, blk_revalidate_zone_cb, &args); if (!ret) { @@ -627,7 +1712,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk, ret = 0; } else { pr_warn("%s: failed to revalidate zones\n", disk->disk_name); - disk_free_zone_bitmaps(disk); + disk_free_zone_resources(disk); } blk_mq_unfreeze_queue(q); |