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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/md/dm-rq.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/md/dm-rq.c | 596 |
1 files changed, 596 insertions, 0 deletions
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c new file mode 100644 index 000000000..80f46e01b --- /dev/null +++ b/drivers/md/dm-rq.c @@ -0,0 +1,596 @@ +/* + * Copyright (C) 2016 Red Hat, Inc. All rights reserved. + * + * This file is released under the GPL. + */ + +#include "dm-core.h" +#include "dm-rq.h" + +#include <linux/blk-mq.h> + +#define DM_MSG_PREFIX "core-rq" + +/* + * One of these is allocated per request. + */ +struct dm_rq_target_io { + struct mapped_device *md; + struct dm_target *ti; + struct request *orig, *clone; + struct kthread_work work; + blk_status_t error; + union map_info info; + struct dm_stats_aux stats_aux; + unsigned long duration_jiffies; + unsigned int n_sectors; + unsigned int completed; +}; + +#define DM_MQ_NR_HW_QUEUES 1 +#define DM_MQ_QUEUE_DEPTH 2048 +static unsigned int dm_mq_nr_hw_queues = DM_MQ_NR_HW_QUEUES; +static unsigned int dm_mq_queue_depth = DM_MQ_QUEUE_DEPTH; + +/* + * Request-based DM's mempools' reserved IOs set by the user. + */ +#define RESERVED_REQUEST_BASED_IOS 256 +static unsigned int reserved_rq_based_ios = RESERVED_REQUEST_BASED_IOS; + +unsigned int dm_get_reserved_rq_based_ios(void) +{ + return __dm_get_module_param(&reserved_rq_based_ios, + RESERVED_REQUEST_BASED_IOS, DM_RESERVED_MAX_IOS); +} + +static unsigned int dm_get_blk_mq_nr_hw_queues(void) +{ + return __dm_get_module_param(&dm_mq_nr_hw_queues, 1, 32); +} + +static unsigned int dm_get_blk_mq_queue_depth(void) +{ + return __dm_get_module_param(&dm_mq_queue_depth, + DM_MQ_QUEUE_DEPTH, BLK_MQ_MAX_DEPTH); +} + +int dm_request_based(struct mapped_device *md) +{ + return queue_is_mq(md->queue); +} + +void dm_start_queue(struct request_queue *q) +{ + blk_mq_unquiesce_queue(q); + blk_mq_kick_requeue_list(q); +} + +void dm_stop_queue(struct request_queue *q) +{ + blk_mq_quiesce_queue(q); +} + +/* + * Partial completion handling for request-based dm + */ +static void end_clone_bio(struct bio *clone) +{ + struct dm_rq_clone_bio_info *info = + container_of(clone, struct dm_rq_clone_bio_info, clone); + struct dm_rq_target_io *tio = info->tio; + unsigned int nr_bytes = info->orig->bi_iter.bi_size; + blk_status_t error = clone->bi_status; + bool is_last = !clone->bi_next; + + bio_put(clone); + + if (tio->error) + /* + * An error has already been detected on the request. + * Once error occurred, just let clone->end_io() handle + * the remainder. + */ + return; + else if (error) { + /* + * Don't notice the error to the upper layer yet. + * The error handling decision is made by the target driver, + * when the request is completed. + */ + tio->error = error; + goto exit; + } + + /* + * I/O for the bio successfully completed. + * Notice the data completion to the upper layer. + */ + tio->completed += nr_bytes; + + /* + * Update the original request. + * Do not use blk_mq_end_request() here, because it may complete + * the original request before the clone, and break the ordering. + */ + if (is_last) + exit: + blk_update_request(tio->orig, BLK_STS_OK, tio->completed); +} + +static struct dm_rq_target_io *tio_from_request(struct request *rq) +{ + return blk_mq_rq_to_pdu(rq); +} + +static void rq_end_stats(struct mapped_device *md, struct request *orig) +{ + if (unlikely(dm_stats_used(&md->stats))) { + struct dm_rq_target_io *tio = tio_from_request(orig); + tio->duration_jiffies = jiffies - tio->duration_jiffies; + dm_stats_account_io(&md->stats, rq_data_dir(orig), + blk_rq_pos(orig), tio->n_sectors, true, + tio->duration_jiffies, &tio->stats_aux); + } +} + +/* + * Don't touch any member of the md after calling this function because + * the md may be freed in dm_put() at the end of this function. + * Or do dm_get() before calling this function and dm_put() later. + */ +static void rq_completed(struct mapped_device *md) +{ + /* + * dm_put() must be at the end of this function. See the comment above + */ + dm_put(md); +} + +/* + * Complete the clone and the original request. + * Must be called without clone's queue lock held, + * see end_clone_request() for more details. + */ +static void dm_end_request(struct request *clone, blk_status_t error) +{ + struct dm_rq_target_io *tio = clone->end_io_data; + struct mapped_device *md = tio->md; + struct request *rq = tio->orig; + + blk_rq_unprep_clone(clone); + tio->ti->type->release_clone_rq(clone, NULL); + + rq_end_stats(md, rq); + blk_mq_end_request(rq, error); + rq_completed(md); +} + +static void __dm_mq_kick_requeue_list(struct request_queue *q, unsigned long msecs) +{ + blk_mq_delay_kick_requeue_list(q, msecs); +} + +void dm_mq_kick_requeue_list(struct mapped_device *md) +{ + __dm_mq_kick_requeue_list(md->queue, 0); +} +EXPORT_SYMBOL(dm_mq_kick_requeue_list); + +static void dm_mq_delay_requeue_request(struct request *rq, unsigned long msecs) +{ + blk_mq_requeue_request(rq, false); + __dm_mq_kick_requeue_list(rq->q, msecs); +} + +static void dm_requeue_original_request(struct dm_rq_target_io *tio, bool delay_requeue) +{ + struct mapped_device *md = tio->md; + struct request *rq = tio->orig; + unsigned long delay_ms = delay_requeue ? 100 : 0; + + rq_end_stats(md, rq); + if (tio->clone) { + blk_rq_unprep_clone(tio->clone); + tio->ti->type->release_clone_rq(tio->clone, NULL); + } + + dm_mq_delay_requeue_request(rq, delay_ms); + rq_completed(md); +} + +static void dm_done(struct request *clone, blk_status_t error, bool mapped) +{ + int r = DM_ENDIO_DONE; + struct dm_rq_target_io *tio = clone->end_io_data; + dm_request_endio_fn rq_end_io = NULL; + + if (tio->ti) { + rq_end_io = tio->ti->type->rq_end_io; + + if (mapped && rq_end_io) + r = rq_end_io(tio->ti, clone, error, &tio->info); + } + + if (unlikely(error == BLK_STS_TARGET)) { + if (req_op(clone) == REQ_OP_DISCARD && + !clone->q->limits.max_discard_sectors) + disable_discard(tio->md); + else if (req_op(clone) == REQ_OP_WRITE_ZEROES && + !clone->q->limits.max_write_zeroes_sectors) + disable_write_zeroes(tio->md); + } + + switch (r) { + case DM_ENDIO_DONE: + /* The target wants to complete the I/O */ + dm_end_request(clone, error); + break; + case DM_ENDIO_INCOMPLETE: + /* The target will handle the I/O */ + return; + case DM_ENDIO_REQUEUE: + /* The target wants to requeue the I/O */ + dm_requeue_original_request(tio, false); + break; + case DM_ENDIO_DELAY_REQUEUE: + /* The target wants to requeue the I/O after a delay */ + dm_requeue_original_request(tio, true); + break; + default: + DMCRIT("unimplemented target endio return value: %d", r); + BUG(); + } +} + +/* + * Request completion handler for request-based dm + */ +static void dm_softirq_done(struct request *rq) +{ + bool mapped = true; + struct dm_rq_target_io *tio = tio_from_request(rq); + struct request *clone = tio->clone; + + if (!clone) { + struct mapped_device *md = tio->md; + + rq_end_stats(md, rq); + blk_mq_end_request(rq, tio->error); + rq_completed(md); + return; + } + + if (rq->rq_flags & RQF_FAILED) + mapped = false; + + dm_done(clone, tio->error, mapped); +} + +/* + * Complete the clone and the original request with the error status + * through softirq context. + */ +static void dm_complete_request(struct request *rq, blk_status_t error) +{ + struct dm_rq_target_io *tio = tio_from_request(rq); + + tio->error = error; + if (likely(!blk_should_fake_timeout(rq->q))) + blk_mq_complete_request(rq); +} + +/* + * Complete the not-mapped clone and the original request with the error status + * through softirq context. + * Target's rq_end_io() function isn't called. + * This may be used when the target's clone_and_map_rq() function fails. + */ +static void dm_kill_unmapped_request(struct request *rq, blk_status_t error) +{ + rq->rq_flags |= RQF_FAILED; + dm_complete_request(rq, error); +} + +static enum rq_end_io_ret end_clone_request(struct request *clone, + blk_status_t error) +{ + struct dm_rq_target_io *tio = clone->end_io_data; + + dm_complete_request(tio->orig, error); + return RQ_END_IO_NONE; +} + +static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig, + void *data) +{ + struct dm_rq_target_io *tio = data; + struct dm_rq_clone_bio_info *info = + container_of(bio, struct dm_rq_clone_bio_info, clone); + + info->orig = bio_orig; + info->tio = tio; + bio->bi_end_io = end_clone_bio; + + return 0; +} + +static int setup_clone(struct request *clone, struct request *rq, + struct dm_rq_target_io *tio, gfp_t gfp_mask) +{ + int r; + + r = blk_rq_prep_clone(clone, rq, &tio->md->mempools->bs, gfp_mask, + dm_rq_bio_constructor, tio); + if (r) + return r; + + clone->end_io = end_clone_request; + clone->end_io_data = tio; + + tio->clone = clone; + + return 0; +} + +static void init_tio(struct dm_rq_target_io *tio, struct request *rq, + struct mapped_device *md) +{ + tio->md = md; + tio->ti = NULL; + tio->clone = NULL; + tio->orig = rq; + tio->error = 0; + tio->completed = 0; + /* + * Avoid initializing info for blk-mq; it passes + * target-specific data through info.ptr + * (see: dm_mq_init_request) + */ + if (!md->init_tio_pdu) + memset(&tio->info, 0, sizeof(tio->info)); +} + +/* + * Returns: + * DM_MAPIO_* : the request has been processed as indicated + * DM_MAPIO_REQUEUE : the original request needs to be immediately requeued + * < 0 : the request was completed due to failure + */ +static int map_request(struct dm_rq_target_io *tio) +{ + int r; + struct dm_target *ti = tio->ti; + struct mapped_device *md = tio->md; + struct request *rq = tio->orig; + struct request *clone = NULL; + blk_status_t ret; + + r = ti->type->clone_and_map_rq(ti, rq, &tio->info, &clone); + switch (r) { + case DM_MAPIO_SUBMITTED: + /* The target has taken the I/O to submit by itself later */ + break; + case DM_MAPIO_REMAPPED: + if (setup_clone(clone, rq, tio, GFP_ATOMIC)) { + /* -ENOMEM */ + ti->type->release_clone_rq(clone, &tio->info); + return DM_MAPIO_REQUEUE; + } + + /* The target has remapped the I/O so dispatch it */ + trace_block_rq_remap(clone, disk_devt(dm_disk(md)), + blk_rq_pos(rq)); + ret = blk_insert_cloned_request(clone); + switch (ret) { + case BLK_STS_OK: + break; + case BLK_STS_RESOURCE: + case BLK_STS_DEV_RESOURCE: + blk_rq_unprep_clone(clone); + blk_mq_cleanup_rq(clone); + tio->ti->type->release_clone_rq(clone, &tio->info); + tio->clone = NULL; + return DM_MAPIO_REQUEUE; + default: + /* must complete clone in terms of original request */ + dm_complete_request(rq, ret); + } + break; + case DM_MAPIO_REQUEUE: + /* The target wants to requeue the I/O */ + break; + case DM_MAPIO_DELAY_REQUEUE: + /* The target wants to requeue the I/O after a delay */ + dm_requeue_original_request(tio, true); + break; + case DM_MAPIO_KILL: + /* The target wants to complete the I/O */ + dm_kill_unmapped_request(rq, BLK_STS_IOERR); + break; + default: + DMCRIT("unimplemented target map return value: %d", r); + BUG(); + } + + return r; +} + +/* DEPRECATED: previously used for request-based merge heuristic in dm_request_fn() */ +ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf) +{ + return sprintf(buf, "%u\n", 0); +} + +ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md, + const char *buf, size_t count) +{ + return count; +} + +static void dm_start_request(struct mapped_device *md, struct request *orig) +{ + blk_mq_start_request(orig); + + if (unlikely(dm_stats_used(&md->stats))) { + struct dm_rq_target_io *tio = tio_from_request(orig); + tio->duration_jiffies = jiffies; + tio->n_sectors = blk_rq_sectors(orig); + dm_stats_account_io(&md->stats, rq_data_dir(orig), + blk_rq_pos(orig), tio->n_sectors, false, 0, + &tio->stats_aux); + } + + /* + * Hold the md reference here for the in-flight I/O. + * We can't rely on the reference count by device opener, + * because the device may be closed during the request completion + * when all bios are completed. + * See the comment in rq_completed() too. + */ + dm_get(md); +} + +static int dm_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, + unsigned int hctx_idx, unsigned int numa_node) +{ + struct mapped_device *md = set->driver_data; + struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq); + + /* + * Must initialize md member of tio, otherwise it won't + * be available in dm_mq_queue_rq. + */ + tio->md = md; + + if (md->init_tio_pdu) { + /* target-specific per-io data is immediately after the tio */ + tio->info.ptr = tio + 1; + } + + return 0; +} + +static blk_status_t dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd) +{ + struct request *rq = bd->rq; + struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq); + struct mapped_device *md = tio->md; + struct dm_target *ti = md->immutable_target; + + /* + * blk-mq's unquiesce may come from outside events, such as + * elevator switch, updating nr_requests or others, and request may + * come during suspend, so simply ask for blk-mq to requeue it. + */ + if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) + return BLK_STS_RESOURCE; + + if (unlikely(!ti)) { + int srcu_idx; + struct dm_table *map; + + map = dm_get_live_table(md, &srcu_idx); + if (unlikely(!map)) { + dm_put_live_table(md, srcu_idx); + return BLK_STS_RESOURCE; + } + ti = dm_table_find_target(map, 0); + dm_put_live_table(md, srcu_idx); + } + + if (ti->type->busy && ti->type->busy(ti)) + return BLK_STS_RESOURCE; + + dm_start_request(md, rq); + + /* Init tio using md established in .init_request */ + init_tio(tio, rq, md); + + /* + * Establish tio->ti before calling map_request(). + */ + tio->ti = ti; + + /* Direct call is fine since .queue_rq allows allocations */ + if (map_request(tio) == DM_MAPIO_REQUEUE) { + /* Undo dm_start_request() before requeuing */ + rq_end_stats(md, rq); + rq_completed(md); + return BLK_STS_RESOURCE; + } + + return BLK_STS_OK; +} + +static const struct blk_mq_ops dm_mq_ops = { + .queue_rq = dm_mq_queue_rq, + .complete = dm_softirq_done, + .init_request = dm_mq_init_request, +}; + +int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t) +{ + struct dm_target *immutable_tgt; + int err; + + md->tag_set = kzalloc_node(sizeof(struct blk_mq_tag_set), GFP_KERNEL, md->numa_node_id); + if (!md->tag_set) + return -ENOMEM; + + md->tag_set->ops = &dm_mq_ops; + md->tag_set->queue_depth = dm_get_blk_mq_queue_depth(); + md->tag_set->numa_node = md->numa_node_id; + md->tag_set->flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING; + md->tag_set->nr_hw_queues = dm_get_blk_mq_nr_hw_queues(); + md->tag_set->driver_data = md; + + md->tag_set->cmd_size = sizeof(struct dm_rq_target_io); + immutable_tgt = dm_table_get_immutable_target(t); + if (immutable_tgt && immutable_tgt->per_io_data_size) { + /* any target-specific per-io data is immediately after the tio */ + md->tag_set->cmd_size += immutable_tgt->per_io_data_size; + md->init_tio_pdu = true; + } + + err = blk_mq_alloc_tag_set(md->tag_set); + if (err) + goto out_kfree_tag_set; + + err = blk_mq_init_allocated_queue(md->tag_set, md->queue); + if (err) + goto out_tag_set; + return 0; + +out_tag_set: + blk_mq_free_tag_set(md->tag_set); +out_kfree_tag_set: + kfree(md->tag_set); + md->tag_set = NULL; + + return err; +} + +void dm_mq_cleanup_mapped_device(struct mapped_device *md) +{ + if (md->tag_set) { + blk_mq_free_tag_set(md->tag_set); + kfree(md->tag_set); + md->tag_set = NULL; + } +} + +module_param(reserved_rq_based_ios, uint, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(reserved_rq_based_ios, "Reserved IOs in request-based mempools"); + +/* Unused, but preserved for userspace compatibility */ +static bool use_blk_mq = true; +module_param(use_blk_mq, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(use_blk_mq, "Use block multiqueue for request-based DM devices"); + +module_param(dm_mq_nr_hw_queues, uint, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(dm_mq_nr_hw_queues, "Number of hardware queues for request-based dm-mq devices"); + +module_param(dm_mq_queue_depth, uint, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(dm_mq_queue_depth, "Queue depth for request-based dm-mq devices"); |