diff options
Diffstat (limited to 'drivers/md/dm-zone.c')
| -rw-r--r-- | drivers/md/dm-zone.c | 647 |
1 files changed, 647 insertions, 0 deletions
diff --git a/drivers/md/dm-zone.c b/drivers/md/dm-zone.c new file mode 100644 index 000000000..eb9832b22 --- /dev/null +++ b/drivers/md/dm-zone.c @@ -0,0 +1,647 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Western Digital Corporation or its affiliates. + */ + +#include <linux/blkdev.h> +#include <linux/mm.h> +#include <linux/sched/mm.h> +#include <linux/slab.h> +#include <linux/bitmap.h> + +#include "dm-core.h" + +#define DM_MSG_PREFIX "zone" + +#define DM_ZONE_INVALID_WP_OFST UINT_MAX + +/* + * For internal zone reports bypassing the top BIO submission path. + */ +static int dm_blk_do_report_zones(struct mapped_device *md, struct dm_table *t, + sector_t sector, unsigned int nr_zones, + report_zones_cb cb, void *data) +{ + struct gendisk *disk = md->disk; + int ret; + struct dm_report_zones_args args = { + .next_sector = sector, + .orig_data = data, + .orig_cb = cb, + }; + + do { + struct dm_target *tgt; + + tgt = dm_table_find_target(t, args.next_sector); + if (WARN_ON_ONCE(!tgt->type->report_zones)) + return -EIO; + + args.tgt = tgt; + ret = tgt->type->report_zones(tgt, &args, + nr_zones - args.zone_idx); + if (ret < 0) + return ret; + } while (args.zone_idx < nr_zones && + args.next_sector < get_capacity(disk)); + + return args.zone_idx; +} + +/* + * User facing dm device block device report zone operation. This calls the + * report_zones operation for each target of a device table. This operation is + * generally implemented by targets using dm_report_zones(). + */ +int dm_blk_report_zones(struct gendisk *disk, sector_t sector, + unsigned int nr_zones, report_zones_cb cb, void *data) +{ + struct mapped_device *md = disk->private_data; + struct dm_table *map; + int srcu_idx, ret; + + if (dm_suspended_md(md)) + return -EAGAIN; + + map = dm_get_live_table(md, &srcu_idx); + if (!map) + return -EIO; + + ret = dm_blk_do_report_zones(md, map, sector, nr_zones, cb, data); + + dm_put_live_table(md, srcu_idx); + + return ret; +} + +static int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx, + void *data) +{ + struct dm_report_zones_args *args = data; + sector_t sector_diff = args->tgt->begin - args->start; + + /* + * Ignore zones beyond the target range. + */ + if (zone->start >= args->start + args->tgt->len) + return 0; + + /* + * Remap the start sector and write pointer position of the zone + * to match its position in the target range. + */ + zone->start += sector_diff; + if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) { + if (zone->cond == BLK_ZONE_COND_FULL) + zone->wp = zone->start + zone->len; + else if (zone->cond == BLK_ZONE_COND_EMPTY) + zone->wp = zone->start; + else + zone->wp += sector_diff; + } + + args->next_sector = zone->start + zone->len; + return args->orig_cb(zone, args->zone_idx++, args->orig_data); +} + +/* + * Helper for drivers of zoned targets to implement struct target_type + * report_zones operation. + */ +int dm_report_zones(struct block_device *bdev, sector_t start, sector_t sector, + struct dm_report_zones_args *args, unsigned int nr_zones) +{ + /* + * Set the target mapping start sector first so that + * dm_report_zones_cb() can correctly remap zone information. + */ + args->start = start; + + return blkdev_report_zones(bdev, sector, nr_zones, + dm_report_zones_cb, args); +} +EXPORT_SYMBOL_GPL(dm_report_zones); + +bool dm_is_zone_write(struct mapped_device *md, struct bio *bio) +{ + struct request_queue *q = md->queue; + + if (!blk_queue_is_zoned(q)) + return false; + + switch (bio_op(bio)) { + case REQ_OP_WRITE_ZEROES: + case REQ_OP_WRITE: + return !op_is_flush(bio->bi_opf) && bio_sectors(bio); + default: + return false; + } +} + +void dm_cleanup_zoned_dev(struct mapped_device *md) +{ + if (md->disk) { + bitmap_free(md->disk->conv_zones_bitmap); + md->disk->conv_zones_bitmap = NULL; + bitmap_free(md->disk->seq_zones_wlock); + md->disk->seq_zones_wlock = NULL; + } + + kvfree(md->zwp_offset); + md->zwp_offset = NULL; + md->nr_zones = 0; +} + +static unsigned int dm_get_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: + 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. Use 0 as for an empty zone. + */ + return 0; + } +} + +static int dm_zone_revalidate_cb(struct blk_zone *zone, unsigned int idx, + void *data) +{ + struct mapped_device *md = data; + struct gendisk *disk = md->disk; + + switch (zone->type) { + case BLK_ZONE_TYPE_CONVENTIONAL: + if (!disk->conv_zones_bitmap) { + disk->conv_zones_bitmap = bitmap_zalloc(disk->nr_zones, + GFP_NOIO); + if (!disk->conv_zones_bitmap) + return -ENOMEM; + } + set_bit(idx, disk->conv_zones_bitmap); + break; + case BLK_ZONE_TYPE_SEQWRITE_REQ: + case BLK_ZONE_TYPE_SEQWRITE_PREF: + if (!disk->seq_zones_wlock) { + disk->seq_zones_wlock = bitmap_zalloc(disk->nr_zones, + GFP_NOIO); + if (!disk->seq_zones_wlock) + return -ENOMEM; + } + if (!md->zwp_offset) { + md->zwp_offset = + kvcalloc(disk->nr_zones, sizeof(unsigned int), + GFP_KERNEL); + if (!md->zwp_offset) + return -ENOMEM; + } + md->zwp_offset[idx] = dm_get_zone_wp_offset(zone); + + break; + default: + DMERR("Invalid zone type 0x%x at sectors %llu", + (int)zone->type, zone->start); + return -ENODEV; + } + + return 0; +} + +/* + * Revalidate the zones of a mapped device to initialize resource necessary + * for zone append emulation. Note that we cannot simply use the block layer + * blk_revalidate_disk_zones() function here as the mapped device is suspended + * (this is called from __bind() context). + */ +static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t) +{ + struct gendisk *disk = md->disk; + unsigned int noio_flag; + int ret; + + /* + * Check if something changed. If yes, cleanup the current resources + * and reallocate everything. + */ + if (!disk->nr_zones || disk->nr_zones != md->nr_zones) + dm_cleanup_zoned_dev(md); + if (md->nr_zones) + return 0; + + /* + * Scan all zones to initialize everything. Ensure that all vmalloc + * operations in this context are done as if GFP_NOIO was specified. + */ + noio_flag = memalloc_noio_save(); + ret = dm_blk_do_report_zones(md, t, 0, disk->nr_zones, + dm_zone_revalidate_cb, md); + memalloc_noio_restore(noio_flag); + if (ret < 0) + goto err; + if (ret != disk->nr_zones) { + ret = -EIO; + goto err; + } + + md->nr_zones = disk->nr_zones; + + return 0; + +err: + DMERR("Revalidate zones failed %d", ret); + dm_cleanup_zoned_dev(md); + return ret; +} + +static int device_not_zone_append_capable(struct dm_target *ti, + struct dm_dev *dev, sector_t start, + sector_t len, void *data) +{ + return !bdev_is_zoned(dev->bdev); +} + +static bool dm_table_supports_zone_append(struct dm_table *t) +{ + for (unsigned int i = 0; i < t->num_targets; i++) { + struct dm_target *ti = dm_table_get_target(t, i); + + if (ti->emulate_zone_append) + return false; + + if (!ti->type->iterate_devices || + ti->type->iterate_devices(ti, device_not_zone_append_capable, NULL)) + return false; + } + + return true; +} + +int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q) +{ + struct mapped_device *md = t->md; + + /* + * For a zoned target, the number of zones should be updated for the + * correct value to be exposed in sysfs queue/nr_zones. + */ + WARN_ON_ONCE(queue_is_mq(q)); + md->disk->nr_zones = bdev_nr_zones(md->disk->part0); + + /* Check if zone append is natively supported */ + if (dm_table_supports_zone_append(t)) { + clear_bit(DMF_EMULATE_ZONE_APPEND, &md->flags); + dm_cleanup_zoned_dev(md); + return 0; + } + + /* + * Mark the mapped device as needing zone append emulation and + * initialize the emulation resources once the capacity is set. + */ + set_bit(DMF_EMULATE_ZONE_APPEND, &md->flags); + if (!get_capacity(md->disk)) + return 0; + + return dm_revalidate_zones(md, t); +} + +static int dm_update_zone_wp_offset_cb(struct blk_zone *zone, unsigned int idx, + void *data) +{ + unsigned int *wp_offset = data; + + *wp_offset = dm_get_zone_wp_offset(zone); + + return 0; +} + +static int dm_update_zone_wp_offset(struct mapped_device *md, unsigned int zno, + unsigned int *wp_ofst) +{ + sector_t sector = zno * bdev_zone_sectors(md->disk->part0); + unsigned int noio_flag; + struct dm_table *t; + int srcu_idx, ret; + + t = dm_get_live_table(md, &srcu_idx); + if (!t) + return -EIO; + + /* + * Ensure that all memory allocations in this context are done as if + * GFP_NOIO was specified. + */ + noio_flag = memalloc_noio_save(); + ret = dm_blk_do_report_zones(md, t, sector, 1, + dm_update_zone_wp_offset_cb, wp_ofst); + memalloc_noio_restore(noio_flag); + + dm_put_live_table(md, srcu_idx); + + if (ret != 1) + return -EIO; + + return 0; +} + +struct orig_bio_details { + enum req_op op; + unsigned int nr_sectors; +}; + +/* + * First phase of BIO mapping for targets with zone append emulation: + * check all BIO that change a zone writer pointer and change zone + * append operations into regular write operations. + */ +static bool dm_zone_map_bio_begin(struct mapped_device *md, + unsigned int zno, struct bio *clone) +{ + sector_t zsectors = bdev_zone_sectors(md->disk->part0); + unsigned int zwp_offset = READ_ONCE(md->zwp_offset[zno]); + + /* + * If the target zone is in an error state, recover by inspecting the + * zone to get its current write pointer position. Note that since the + * target zone is already locked, a BIO issuing context should never + * see the zone write in the DM_ZONE_UPDATING_WP_OFST state. + */ + if (zwp_offset == DM_ZONE_INVALID_WP_OFST) { + if (dm_update_zone_wp_offset(md, zno, &zwp_offset)) + return false; + WRITE_ONCE(md->zwp_offset[zno], zwp_offset); + } + + switch (bio_op(clone)) { + case REQ_OP_ZONE_RESET: + case REQ_OP_ZONE_FINISH: + return true; + case REQ_OP_WRITE_ZEROES: + case REQ_OP_WRITE: + /* Writes must be aligned to the zone write pointer */ + if ((clone->bi_iter.bi_sector & (zsectors - 1)) != zwp_offset) + return false; + break; + case REQ_OP_ZONE_APPEND: + /* + * Change zone append operations into a non-mergeable regular + * writes directed at the current write pointer position of the + * target zone. + */ + clone->bi_opf = REQ_OP_WRITE | REQ_NOMERGE | + (clone->bi_opf & (~REQ_OP_MASK)); + clone->bi_iter.bi_sector += zwp_offset; + break; + default: + DMWARN_LIMIT("Invalid BIO operation"); + return false; + } + + /* Cannot write to a full zone */ + if (zwp_offset >= zsectors) + return false; + + return true; +} + +/* + * Second phase of BIO mapping for targets with zone append emulation: + * update the zone write pointer offset array to account for the additional + * data written to a zone. Note that at this point, the remapped clone BIO + * may already have completed, so we do not touch it. + */ +static blk_status_t dm_zone_map_bio_end(struct mapped_device *md, unsigned int zno, + struct orig_bio_details *orig_bio_details, + unsigned int nr_sectors) +{ + unsigned int zwp_offset = READ_ONCE(md->zwp_offset[zno]); + + /* The clone BIO may already have been completed and failed */ + if (zwp_offset == DM_ZONE_INVALID_WP_OFST) + return BLK_STS_IOERR; + + /* Update the zone wp offset */ + switch (orig_bio_details->op) { + case REQ_OP_ZONE_RESET: + WRITE_ONCE(md->zwp_offset[zno], 0); + return BLK_STS_OK; + case REQ_OP_ZONE_FINISH: + WRITE_ONCE(md->zwp_offset[zno], + bdev_zone_sectors(md->disk->part0)); + return BLK_STS_OK; + case REQ_OP_WRITE_ZEROES: + case REQ_OP_WRITE: + WRITE_ONCE(md->zwp_offset[zno], zwp_offset + nr_sectors); + return BLK_STS_OK; + case REQ_OP_ZONE_APPEND: + /* + * Check that the target did not truncate the write operation + * emulating a zone append. + */ + if (nr_sectors != orig_bio_details->nr_sectors) { + DMWARN_LIMIT("Truncated write for zone append"); + return BLK_STS_IOERR; + } + WRITE_ONCE(md->zwp_offset[zno], zwp_offset + nr_sectors); + return BLK_STS_OK; + default: + DMWARN_LIMIT("Invalid BIO operation"); + return BLK_STS_IOERR; + } +} + +static inline void dm_zone_lock(struct gendisk *disk, unsigned int zno, + struct bio *clone) +{ + if (WARN_ON_ONCE(bio_flagged(clone, BIO_ZONE_WRITE_LOCKED))) + return; + + wait_on_bit_lock_io(disk->seq_zones_wlock, zno, TASK_UNINTERRUPTIBLE); + bio_set_flag(clone, BIO_ZONE_WRITE_LOCKED); +} + +static inline void dm_zone_unlock(struct gendisk *disk, unsigned int zno, + struct bio *clone) +{ + if (!bio_flagged(clone, BIO_ZONE_WRITE_LOCKED)) + return; + + WARN_ON_ONCE(!test_bit(zno, disk->seq_zones_wlock)); + clear_bit_unlock(zno, disk->seq_zones_wlock); + smp_mb__after_atomic(); + wake_up_bit(disk->seq_zones_wlock, zno); + + bio_clear_flag(clone, BIO_ZONE_WRITE_LOCKED); +} + +static bool dm_need_zone_wp_tracking(struct bio *bio) +{ + /* + * Special processing is not needed for operations that do not need the + * zone write lock, that is, all operations that target conventional + * zones and all operations that do not modify directly a sequential + * zone write pointer. + */ + if (op_is_flush(bio->bi_opf) && !bio_sectors(bio)) + return false; + switch (bio_op(bio)) { + case REQ_OP_WRITE_ZEROES: + case REQ_OP_WRITE: + case REQ_OP_ZONE_RESET: + case REQ_OP_ZONE_FINISH: + case REQ_OP_ZONE_APPEND: + return bio_zone_is_seq(bio); + default: + return false; + } +} + +/* + * Special IO mapping for targets needing zone append emulation. + */ +int dm_zone_map_bio(struct dm_target_io *tio) +{ + struct dm_io *io = tio->io; + struct dm_target *ti = tio->ti; + struct mapped_device *md = io->md; + struct bio *clone = &tio->clone; + struct orig_bio_details orig_bio_details; + unsigned int zno; + blk_status_t sts; + int r; + + /* + * IOs that do not change a zone write pointer do not need + * any additional special processing. + */ + if (!dm_need_zone_wp_tracking(clone)) + return ti->type->map(ti, clone); + + /* Lock the target zone */ + zno = bio_zone_no(clone); + dm_zone_lock(md->disk, zno, clone); + + orig_bio_details.nr_sectors = bio_sectors(clone); + orig_bio_details.op = bio_op(clone); + + /* + * Check that the bio and the target zone write pointer offset are + * both valid, and if the bio is a zone append, remap it to a write. + */ + if (!dm_zone_map_bio_begin(md, zno, clone)) { + dm_zone_unlock(md->disk, zno, clone); + return DM_MAPIO_KILL; + } + + /* Let the target do its work */ + r = ti->type->map(ti, clone); + switch (r) { + case DM_MAPIO_SUBMITTED: + /* + * The target submitted the clone BIO. The target zone will + * be unlocked on completion of the clone. + */ + sts = dm_zone_map_bio_end(md, zno, &orig_bio_details, + *tio->len_ptr); + break; + case DM_MAPIO_REMAPPED: + /* + * The target only remapped the clone BIO. In case of error, + * unlock the target zone here as the clone will not be + * submitted. + */ + sts = dm_zone_map_bio_end(md, zno, &orig_bio_details, + *tio->len_ptr); + if (sts != BLK_STS_OK) + dm_zone_unlock(md->disk, zno, clone); + break; + case DM_MAPIO_REQUEUE: + case DM_MAPIO_KILL: + default: + dm_zone_unlock(md->disk, zno, clone); + sts = BLK_STS_IOERR; + break; + } + + if (sts != BLK_STS_OK) + return DM_MAPIO_KILL; + + return r; +} + +/* + * IO completion callback called from clone_endio(). + */ +void dm_zone_endio(struct dm_io *io, struct bio *clone) +{ + struct mapped_device *md = io->md; + struct gendisk *disk = md->disk; + struct bio *orig_bio = io->orig_bio; + unsigned int zwp_offset; + unsigned int zno; + + /* + * For targets that do not emulate zone append, we only need to + * handle native zone-append bios. + */ + if (!dm_emulate_zone_append(md)) { + /* + * Get the offset within the zone of the written sector + * and add that to the original bio sector position. + */ + if (clone->bi_status == BLK_STS_OK && + bio_op(clone) == REQ_OP_ZONE_APPEND) { + sector_t mask = + (sector_t)bdev_zone_sectors(disk->part0) - 1; + + orig_bio->bi_iter.bi_sector += + clone->bi_iter.bi_sector & mask; + } + + return; + } + + /* + * For targets that do emulate zone append, if the clone BIO does not + * own the target zone write lock, we have nothing to do. + */ + if (!bio_flagged(clone, BIO_ZONE_WRITE_LOCKED)) + return; + + zno = bio_zone_no(orig_bio); + + if (clone->bi_status != BLK_STS_OK) { + /* + * BIOs that modify a zone write pointer may leave the zone + * in an unknown state in case of failure (e.g. the write + * pointer was only partially advanced). In this case, set + * the target zone write pointer as invalid unless it is + * already being updated. + */ + WRITE_ONCE(md->zwp_offset[zno], DM_ZONE_INVALID_WP_OFST); + } else if (bio_op(orig_bio) == REQ_OP_ZONE_APPEND) { + /* + * Get the written sector for zone append operation that were + * emulated using regular write operations. + */ + zwp_offset = READ_ONCE(md->zwp_offset[zno]); + if (WARN_ON_ONCE(zwp_offset < bio_sectors(orig_bio))) + WRITE_ONCE(md->zwp_offset[zno], + DM_ZONE_INVALID_WP_OFST); + else + orig_bio->bi_iter.bi_sector += + zwp_offset - bio_sectors(orig_bio); + } + + dm_zone_unlock(disk, zno, clone); +} |