| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Mike Snitzer | 6046 | 43.81% | 123 | 28.47% |
| Christoph Hellwig | 1296 | 9.39% | 54 | 12.50% |
| Ming Lei | 1266 | 9.17% | 12 | 2.78% |
| Mikulas Patocka | 1025 | 7.43% | 45 | 10.42% |
| Kiyoshi Ueda | 964 | 6.99% | 15 | 3.47% |
| Alasdair G. Kergon | 376 | 2.72% | 29 | 6.71% |
| Michael Christie | 361 | 2.62% | 6 | 1.39% |
| Dan J Williams | 330 | 2.39% | 6 | 1.39% |
| Alan Cox | 327 | 2.37% | 2 | 0.46% |
| Milan Broz | 215 | 1.56% | 11 | 2.55% |
| Andrew Morton | 192 | 1.39% | 11 | 2.55% |
| Damien Le Moal | 174 | 1.26% | 6 | 1.39% |
| Jane Chu | 125 | 0.91% | 2 | 0.46% |
| Vivek Goyal | 119 | 0.86% | 2 | 0.46% |
| Mike Anderson | 109 | 0.79% | 5 | 1.16% |
| Jeff Mahoney | 109 | 0.79% | 6 | 1.39% |
| Bart Van Assche | 79 | 0.57% | 11 | 2.55% |
| Joe Thornber | 51 | 0.37% | 7 | 1.62% |
| Satya Tangirala | 46 | 0.33% | 2 | 0.46% |
| Jun'ichi Nomura | 40 | 0.29% | 9 | 2.08% |
| Tejun Heo | 39 | 0.28% | 7 | 1.62% |
| Jens Axboe | 38 | 0.28% | 6 | 1.39% |
| Toshi Kani | 37 | 0.27% | 1 | 0.23% |
| Tushar Sugandhi | 30 | 0.22% | 2 | 0.46% |
| Eric Dumazet | 28 | 0.20% | 1 | 0.23% |
| Keith Busch | 28 | 0.20% | 2 | 0.46% |
| Kent Overstreet | 24 | 0.17% | 2 | 0.46% |
| Hou Tao | 22 | 0.16% | 1 | 0.23% |
| Darrick J. Wong | 22 | 0.16% | 1 | 0.23% |
| Benjamin Marzinski | 22 | 0.16% | 1 | 0.23% |
| Johannes Thumshirn | 22 | 0.16% | 1 | 0.23% |
| David Teigland | 20 | 0.14% | 1 | 0.23% |
| lijiazi | 19 | 0.14% | 1 | 0.23% |
| Konstantin Khlebnikov | 17 | 0.12% | 1 | 0.23% |
| Michael Lass | 16 | 0.12% | 1 | 0.23% |
| Shin'ichiro Kawasaki | 14 | 0.10% | 1 | 0.23% |
| Elena Reshetova | 11 | 0.08% | 1 | 0.23% |
| Kevin Corry | 11 | 0.08% | 2 | 0.46% |
| Luis R. Rodriguez | 9 | 0.07% | 1 | 0.23% |
| Martin K. Petersen | 9 | 0.07% | 1 | 0.23% |
| Neil Brown | 8 | 0.06% | 2 | 0.46% |
| Tahsin Erdogan | 8 | 0.06% | 1 | 0.23% |
| Hannes Reinecke | 8 | 0.06% | 1 | 0.23% |
| Peter Zijlstra | 7 | 0.05% | 2 | 0.46% |
| Eric Biggers | 6 | 0.04% | 2 | 0.46% |
| Al Viro | 6 | 0.04% | 1 | 0.23% |
| Minfei Huang | 5 | 0.04% | 1 | 0.23% |
| Michał Mirosław | 5 | 0.04% | 1 | 0.23% |
| Sami Tolvanen | 5 | 0.04% | 1 | 0.23% |
| Edward Goggin | 5 | 0.04% | 1 | 0.23% |
| Kirill V Tkhai | 5 | 0.04% | 1 | 0.23% |
| Jeffle Xu | 4 | 0.03% | 1 | 0.23% |
| Shiyang Ruan | 4 | 0.03% | 1 | 0.23% |
| Nikanth Karthikesan | 4 | 0.03% | 1 | 0.23% |
| Peng Wang | 4 | 0.03% | 1 | 0.23% |
| Denis Semakin | 4 | 0.03% | 1 | 0.23% |
| Michael Callahan | 3 | 0.02% | 1 | 0.23% |
| Ingo Molnar | 3 | 0.02% | 1 | 0.23% |
| Gustavo A. R. Silva | 3 | 0.02% | 1 | 0.23% |
| Stefan Bader | 2 | 0.01% | 1 | 0.23% |
| Arjan van de Ven | 2 | 0.01% | 1 | 0.23% |
| Mark Rutland | 2 | 0.01% | 1 | 0.23% |
| Bryn M. Reeves | 1 | 0.01% | 1 | 0.23% |
| Linus Torvalds | 1 | 0.01% | 1 | 0.23% |
| Pranith Kumar | 1 | 0.01% | 1 | 0.23% |
| Richard Kennedy | 1 | 0.01% | 1 | 0.23% |
| Daniel Walker | 1 | 0.01% | 1 | 0.23% |
| Peter Rajnoha | 1 | 0.01% | 1 | 0.23% |
| Pankaj Gupta | 1 | 0.01% | 1 | 0.23% |
| Ajay Joshi | 1 | 0.01% | 1 | 0.23% |
| Total | 13799 | 432 |
/* * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. * * This file is released under the GPL. */ #include "dm-core.h" #include "dm-rq.h" #include "dm-uevent.h" #include "dm-ima.h" #include <linux/init.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/sched/mm.h> #include <linux/sched/signal.h> #include <linux/blkpg.h> #include <linux/bio.h> #include <linux/mempool.h> #include <linux/dax.h> #include <linux/slab.h> #include <linux/idr.h> #include <linux/uio.h> #include <linux/hdreg.h> #include <linux/delay.h> #include <linux/wait.h> #include <linux/pr.h> #include <linux/refcount.h> #include <linux/part_stat.h> #include <linux/blk-crypto.h> #include <linux/blk-crypto-profile.h> #define DM_MSG_PREFIX "core" /* * Cookies are numeric values sent with CHANGE and REMOVE * uevents while resuming, removing or renaming the device. */ #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE" #define DM_COOKIE_LENGTH 24 /* * For REQ_POLLED fs bio, this flag is set if we link mapped underlying * dm_io into one list, and reuse bio->bi_private as the list head. Before * ending this fs bio, we will recover its ->bi_private. */ #define REQ_DM_POLL_LIST REQ_DRV static const char *_name = DM_NAME; static unsigned int major = 0; static unsigned int _major = 0; static DEFINE_IDR(_minor_idr); static DEFINE_SPINLOCK(_minor_lock); static void do_deferred_remove(struct work_struct *w); static DECLARE_WORK(deferred_remove_work, do_deferred_remove); static struct workqueue_struct *deferred_remove_workqueue; atomic_t dm_global_event_nr = ATOMIC_INIT(0); DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq); void dm_issue_global_event(void) { atomic_inc(&dm_global_event_nr); wake_up(&dm_global_eventq); } DEFINE_STATIC_KEY_FALSE(stats_enabled); DEFINE_STATIC_KEY_FALSE(swap_bios_enabled); DEFINE_STATIC_KEY_FALSE(zoned_enabled); /* * One of these is allocated (on-stack) per original bio. */ struct clone_info { struct dm_table *map; struct bio *bio; struct dm_io *io; sector_t sector; unsigned sector_count; bool is_abnormal_io:1; bool submit_as_polled:1; }; static inline struct dm_target_io *clone_to_tio(struct bio *clone) { return container_of(clone, struct dm_target_io, clone); } void *dm_per_bio_data(struct bio *bio, size_t data_size) { if (!dm_tio_flagged(clone_to_tio(bio), DM_TIO_INSIDE_DM_IO)) return (char *)bio - DM_TARGET_IO_BIO_OFFSET - data_size; return (char *)bio - DM_IO_BIO_OFFSET - data_size; } EXPORT_SYMBOL_GPL(dm_per_bio_data); struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size) { struct dm_io *io = (struct dm_io *)((char *)data + data_size); if (io->magic == DM_IO_MAGIC) return (struct bio *)((char *)io + DM_IO_BIO_OFFSET); BUG_ON(io->magic != DM_TIO_MAGIC); return (struct bio *)((char *)io + DM_TARGET_IO_BIO_OFFSET); } EXPORT_SYMBOL_GPL(dm_bio_from_per_bio_data); unsigned dm_bio_get_target_bio_nr(const struct bio *bio) { return container_of(bio, struct dm_target_io, clone)->target_bio_nr; } EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr); #define MINOR_ALLOCED ((void *)-1) #define DM_NUMA_NODE NUMA_NO_NODE static int dm_numa_node = DM_NUMA_NODE; #define DEFAULT_SWAP_BIOS (8 * 1048576 / PAGE_SIZE) static int swap_bios = DEFAULT_SWAP_BIOS; static int get_swap_bios(void) { int latch = READ_ONCE(swap_bios); if (unlikely(latch <= 0)) latch = DEFAULT_SWAP_BIOS; return latch; } struct table_device { struct list_head list; refcount_t count; struct dm_dev dm_dev; }; /* * Bio-based DM's mempools' reserved IOs set by the user. */ #define RESERVED_BIO_BASED_IOS 16 static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS; static int __dm_get_module_param_int(int *module_param, int min, int max) { int param = READ_ONCE(*module_param); int modified_param = 0; bool modified = true; if (param < min) modified_param = min; else if (param > max) modified_param = max; else modified = false; if (modified) { (void)cmpxchg(module_param, param, modified_param); param = modified_param; } return param; } unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max) { unsigned param = READ_ONCE(*module_param); unsigned modified_param = 0; if (!param) modified_param = def; else if (param > max) modified_param = max; if (modified_param) { (void)cmpxchg(module_param, param, modified_param); param = modified_param; } return param; } unsigned dm_get_reserved_bio_based_ios(void) { return __dm_get_module_param(&reserved_bio_based_ios, RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS); } EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios); static unsigned dm_get_numa_node(void) { return __dm_get_module_param_int(&dm_numa_node, DM_NUMA_NODE, num_online_nodes() - 1); } static int __init local_init(void) { int r; r = dm_uevent_init(); if (r) return r; deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1); if (!deferred_remove_workqueue) { r = -ENOMEM; goto out_uevent_exit; } _major = major; r = register_blkdev(_major, _name); if (r < 0) goto out_free_workqueue; if (!_major) _major = r; return 0; out_free_workqueue: destroy_workqueue(deferred_remove_workqueue); out_uevent_exit: dm_uevent_exit(); return r; } static void local_exit(void) { flush_scheduled_work(); destroy_workqueue(deferred_remove_workqueue); unregister_blkdev(_major, _name); dm_uevent_exit(); _major = 0; DMINFO("cleaned up"); } static int (*_inits[])(void) __initdata = { local_init, dm_target_init, dm_linear_init, dm_stripe_init, dm_io_init, dm_kcopyd_init, dm_interface_init, dm_statistics_init, }; static void (*_exits[])(void) = { local_exit, dm_target_exit, dm_linear_exit, dm_stripe_exit, dm_io_exit, dm_kcopyd_exit, dm_interface_exit, dm_statistics_exit, }; static int __init dm_init(void) { const int count = ARRAY_SIZE(_inits); int r, i; #if (IS_ENABLED(CONFIG_IMA) && !IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE)) DMWARN("CONFIG_IMA_DISABLE_HTABLE is disabled." " Duplicate IMA measurements will not be recorded in the IMA log."); #endif for (i = 0; i < count; i++) { r = _inits[i](); if (r) goto bad; } return 0; bad: while (i--) _exits[i](); return r; } static void __exit dm_exit(void) { int i = ARRAY_SIZE(_exits); while (i--) _exits[i](); /* * Should be empty by this point. */ idr_destroy(&_minor_idr); } /* * Block device functions */ int dm_deleting_md(struct mapped_device *md) { return test_bit(DMF_DELETING, &md->flags); } static int dm_blk_open(struct block_device *bdev, fmode_t mode) { struct mapped_device *md; spin_lock(&_minor_lock); md = bdev->bd_disk->private_data; if (!md) goto out; if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) { md = NULL; goto out; } dm_get(md); atomic_inc(&md->open_count); out: spin_unlock(&_minor_lock); return md ? 0 : -ENXIO; } static void dm_blk_close(struct gendisk *disk, fmode_t mode) { struct mapped_device *md; spin_lock(&_minor_lock); md = disk->private_data; if (WARN_ON(!md)) goto out; if (atomic_dec_and_test(&md->open_count) && (test_bit(DMF_DEFERRED_REMOVE, &md->flags))) queue_work(deferred_remove_workqueue, &deferred_remove_work); dm_put(md); out: spin_unlock(&_minor_lock); } int dm_open_count(struct mapped_device *md) { return atomic_read(&md->open_count); } /* * Guarantees nothing is using the device before it's deleted. */ int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred) { int r = 0; spin_lock(&_minor_lock); if (dm_open_count(md)) { r = -EBUSY; if (mark_deferred) set_bit(DMF_DEFERRED_REMOVE, &md->flags); } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags)) r = -EEXIST; else set_bit(DMF_DELETING, &md->flags); spin_unlock(&_minor_lock); return r; } int dm_cancel_deferred_remove(struct mapped_device *md) { int r = 0; spin_lock(&_minor_lock); if (test_bit(DMF_DELETING, &md->flags)) r = -EBUSY; else clear_bit(DMF_DEFERRED_REMOVE, &md->flags); spin_unlock(&_minor_lock); return r; } static void do_deferred_remove(struct work_struct *w) { dm_deferred_remove(); } static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) { struct mapped_device *md = bdev->bd_disk->private_data; return dm_get_geometry(md, geo); } static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx, struct block_device **bdev) { struct dm_target *ti; struct dm_table *map; int r; retry: r = -ENOTTY; map = dm_get_live_table(md, srcu_idx); if (!map || !dm_table_get_size(map)) return r; /* We only support devices that have a single target */ if (map->num_targets != 1) return r; ti = dm_table_get_target(map, 0); if (!ti->type->prepare_ioctl) return r; if (dm_suspended_md(md)) return -EAGAIN; r = ti->type->prepare_ioctl(ti, bdev); if (r == -ENOTCONN && !fatal_signal_pending(current)) { dm_put_live_table(md, *srcu_idx); msleep(10); goto retry; } return r; } static void dm_unprepare_ioctl(struct mapped_device *md, int srcu_idx) { dm_put_live_table(md, srcu_idx); } static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { struct mapped_device *md = bdev->bd_disk->private_data; int r, srcu_idx; r = dm_prepare_ioctl(md, &srcu_idx, &bdev); if (r < 0) goto out; if (r > 0) { /* * Target determined this ioctl is being issued against a * subset of the parent bdev; require extra privileges. */ if (!capable(CAP_SYS_RAWIO)) { DMDEBUG_LIMIT( "%s: sending ioctl %x to DM device without required privilege.", current->comm, cmd); r = -ENOIOCTLCMD; goto out; } } if (!bdev->bd_disk->fops->ioctl) r = -ENOTTY; else r = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg); out: dm_unprepare_ioctl(md, srcu_idx); return r; } u64 dm_start_time_ns_from_clone(struct bio *bio) { return jiffies_to_nsecs(clone_to_tio(bio)->io->start_time); } EXPORT_SYMBOL_GPL(dm_start_time_ns_from_clone); static bool bio_is_flush_with_data(struct bio *bio) { return ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size); } static void dm_io_acct(struct dm_io *io, bool end) { struct dm_stats_aux *stats_aux = &io->stats_aux; unsigned long start_time = io->start_time; struct mapped_device *md = io->md; struct bio *bio = io->orig_bio; unsigned int sectors; /* * If REQ_PREFLUSH set, don't account payload, it will be * submitted (and accounted) after this flush completes. */ if (bio_is_flush_with_data(bio)) sectors = 0; else if (likely(!(dm_io_flagged(io, DM_IO_WAS_SPLIT)))) sectors = bio_sectors(bio); else sectors = io->sectors; if (!end) bdev_start_io_acct(bio->bi_bdev, sectors, bio_op(bio), start_time); else bdev_end_io_acct(bio->bi_bdev, bio_op(bio), start_time); if (static_branch_unlikely(&stats_enabled) && unlikely(dm_stats_used(&md->stats))) { sector_t sector; if (likely(!dm_io_flagged(io, DM_IO_WAS_SPLIT))) sector = bio->bi_iter.bi_sector; else sector = bio_end_sector(bio) - io->sector_offset; dm_stats_account_io(&md->stats, bio_data_dir(bio), sector, sectors, end, start_time, stats_aux); } } static void __dm_start_io_acct(struct dm_io *io) { dm_io_acct(io, false); } static void dm_start_io_acct(struct dm_io *io, struct bio *clone) { /* * Ensure IO accounting is only ever started once. */ if (dm_io_flagged(io, DM_IO_ACCOUNTED)) return; /* Expect no possibility for race unless DM_TIO_IS_DUPLICATE_BIO. */ if (!clone || likely(dm_tio_is_normal(clone_to_tio(clone)))) { dm_io_set_flag(io, DM_IO_ACCOUNTED); } else { unsigned long flags; /* Can afford locking given DM_TIO_IS_DUPLICATE_BIO */ spin_lock_irqsave(&io->lock, flags); if (dm_io_flagged(io, DM_IO_ACCOUNTED)) { spin_unlock_irqrestore(&io->lock, flags); return; } dm_io_set_flag(io, DM_IO_ACCOUNTED); spin_unlock_irqrestore(&io->lock, flags); } __dm_start_io_acct(io); } static void dm_end_io_acct(struct dm_io *io) { dm_io_acct(io, true); } static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio) { struct dm_io *io; struct dm_target_io *tio; struct bio *clone; clone = bio_alloc_clone(NULL, bio, GFP_NOIO, &md->mempools->io_bs); tio = clone_to_tio(clone); tio->flags = 0; dm_tio_set_flag(tio, DM_TIO_INSIDE_DM_IO); tio->io = NULL; io = container_of(tio, struct dm_io, tio); io->magic = DM_IO_MAGIC; io->status = BLK_STS_OK; /* one ref is for submission, the other is for completion */ atomic_set(&io->io_count, 2); this_cpu_inc(*md->pending_io); io->orig_bio = bio; io->md = md; spin_lock_init(&io->lock); io->start_time = jiffies; io->flags = 0; if (static_branch_unlikely(&stats_enabled)) dm_stats_record_start(&md->stats, &io->stats_aux); return io; } static void free_io(struct dm_io *io) { bio_put(&io->tio.clone); } static struct bio *alloc_tio(struct clone_info *ci, struct dm_target *ti, unsigned target_bio_nr, unsigned *len, gfp_t gfp_mask) { struct mapped_device *md = ci->io->md; struct dm_target_io *tio; struct bio *clone; if (!ci->io->tio.io) { /* the dm_target_io embedded in ci->io is available */ tio = &ci->io->tio; /* alloc_io() already initialized embedded clone */ clone = &tio->clone; } else { clone = bio_alloc_clone(NULL, ci->bio, gfp_mask, &md->mempools->bs); if (!clone) return NULL; /* REQ_DM_POLL_LIST shouldn't be inherited */ clone->bi_opf &= ~REQ_DM_POLL_LIST; tio = clone_to_tio(clone); tio->flags = 0; /* also clears DM_TIO_INSIDE_DM_IO */ } tio->magic = DM_TIO_MAGIC; tio->io = ci->io; tio->ti = ti; tio->target_bio_nr = target_bio_nr; tio->len_ptr = len; tio->old_sector = 0; /* Set default bdev, but target must bio_set_dev() before issuing IO */ clone->bi_bdev = md->disk->part0; if (unlikely(ti->needs_bio_set_dev)) bio_set_dev(clone, md->disk->part0); if (len) { clone->bi_iter.bi_size = to_bytes(*len); if (bio_integrity(clone)) bio_integrity_trim(clone); } return clone; } static void free_tio(struct bio *clone) { if (dm_tio_flagged(clone_to_tio(clone), DM_TIO_INSIDE_DM_IO)) return; bio_put(clone); } /* * Add the bio to the list of deferred io. */ static void queue_io(struct mapped_device *md, struct bio *bio) { unsigned long flags; spin_lock_irqsave(&md->deferred_lock, flags); bio_list_add(&md->deferred, bio); spin_unlock_irqrestore(&md->deferred_lock, flags); queue_work(md->wq, &md->work); } /* * Everyone (including functions in this file), should use this * function to access the md->map field, and make sure they call * dm_put_live_table() when finished. */ struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier) { *srcu_idx = srcu_read_lock(&md->io_barrier); return srcu_dereference(md->map, &md->io_barrier); } void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier) { srcu_read_unlock(&md->io_barrier, srcu_idx); } void dm_sync_table(struct mapped_device *md) { synchronize_srcu(&md->io_barrier); synchronize_rcu_expedited(); } /* * A fast alternative to dm_get_live_table/dm_put_live_table. * The caller must not block between these two functions. */ static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU) { rcu_read_lock(); return rcu_dereference(md->map); } static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU) { rcu_read_unlock(); } static inline struct dm_table *dm_get_live_table_bio(struct mapped_device *md, int *srcu_idx, blk_opf_t bio_opf) { if (bio_opf & REQ_NOWAIT) return dm_get_live_table_fast(md); else return dm_get_live_table(md, srcu_idx); } static inline void dm_put_live_table_bio(struct mapped_device *md, int srcu_idx, blk_opf_t bio_opf) { if (bio_opf & REQ_NOWAIT) dm_put_live_table_fast(md); else dm_put_live_table(md, srcu_idx); } static char *_dm_claim_ptr = "I belong to device-mapper"; /* * Open a table device so we can use it as a map destination. */ static int open_table_device(struct table_device *td, dev_t dev, struct mapped_device *md) { struct block_device *bdev; u64 part_off; int r; BUG_ON(td->dm_dev.bdev); bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr); if (IS_ERR(bdev)) return PTR_ERR(bdev); r = bd_link_disk_holder(bdev, dm_disk(md)); if (r) { blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL); return r; } td->dm_dev.bdev = bdev; td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev, &part_off, NULL, NULL); return 0; } /* * Close a table device that we've been using. */ static void close_table_device(struct table_device *td, struct mapped_device *md) { if (!td->dm_dev.bdev) return; bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md)); blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL); put_dax(td->dm_dev.dax_dev); td->dm_dev.bdev = NULL; td->dm_dev.dax_dev = NULL; } static struct table_device *find_table_device(struct list_head *l, dev_t dev, fmode_t mode) { struct table_device *td; list_for_each_entry(td, l, list) if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode) return td; return NULL; } int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, struct dm_dev **result) { int r; struct table_device *td; mutex_lock(&md->table_devices_lock); td = find_table_device(&md->table_devices, dev, mode); if (!td) { td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id); if (!td) { mutex_unlock(&md->table_devices_lock); return -ENOMEM; } td->dm_dev.mode = mode; td->dm_dev.bdev = NULL; if ((r = open_table_device(td, dev, md))) { mutex_unlock(&md->table_devices_lock); kfree(td); return r; } format_dev_t(td->dm_dev.name, dev); refcount_set(&td->count, 1); list_add(&td->list, &md->table_devices); } else { refcount_inc(&td->count); } mutex_unlock(&md->table_devices_lock); *result = &td->dm_dev; return 0; } void dm_put_table_device(struct mapped_device *md, struct dm_dev *d) { struct table_device *td = container_of(d, struct table_device, dm_dev); mutex_lock(&md->table_devices_lock); if (refcount_dec_and_test(&td->count)) { close_table_device(td, md); list_del(&td->list); kfree(td); } mutex_unlock(&md->table_devices_lock); } static void free_table_devices(struct list_head *devices) { struct list_head *tmp, *next; list_for_each_safe(tmp, next, devices) { struct table_device *td = list_entry(tmp, struct table_device, list); DMWARN("dm_destroy: %s still exists with %d references", td->dm_dev.name, refcount_read(&td->count)); kfree(td); } } /* * Get the geometry associated with a dm device */ int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) { *geo = md->geometry; return 0; } /* * Set the geometry of a device. */ int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) { sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; if (geo->start > sz) { DMERR("Start sector is beyond the geometry limits."); return -EINVAL; } md->geometry = *geo; return 0; } static int __noflush_suspending(struct mapped_device *md) { return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); } static void dm_requeue_add_io(struct dm_io *io, bool first_stage) { struct mapped_device *md = io->md; if (first_stage) { struct dm_io *next = md->requeue_list; md->requeue_list = io; io->next = next; } else { bio_list_add_head(&md->deferred, io->orig_bio); } } static void dm_kick_requeue(struct mapped_device *md, bool first_stage) { if (first_stage) queue_work(md->wq, &md->requeue_work); else queue_work(md->wq, &md->work); } /* * Return true if the dm_io's original bio is requeued. * io->status is updated with error if requeue disallowed. */ static bool dm_handle_requeue(struct dm_io *io, bool first_stage) { struct bio *bio = io->orig_bio; bool handle_requeue = (io->status == BLK_STS_DM_REQUEUE); bool handle_polled_eagain = ((io->status == BLK_STS_AGAIN) && (bio->bi_opf & REQ_POLLED)); struct mapped_device *md = io->md; bool requeued = false; if (handle_requeue || handle_polled_eagain) { unsigned long flags; if (bio->bi_opf & REQ_POLLED) { /* * Upper layer won't help us poll split bio * (io->orig_bio may only reflect a subset of the * pre-split original) so clear REQ_POLLED. */ bio_clear_polled(bio); } /* * Target requested pushing back the I/O or * polled IO hit BLK_STS_AGAIN. */ spin_lock_irqsave(&md->deferred_lock, flags); if ((__noflush_suspending(md) && !WARN_ON_ONCE(dm_is_zone_write(md, bio))) || handle_polled_eagain || first_stage) { dm_requeue_add_io(io, first_stage); requeued = true; } else { /* * noflush suspend was interrupted or this is * a write to a zoned target. */ io->status = BLK_STS_IOERR; } spin_unlock_irqrestore(&md->deferred_lock, flags); } if (requeued) dm_kick_requeue(md, first_stage); return requeued; } static void __dm_io_complete(struct dm_io *io, bool first_stage) { struct bio *bio = io->orig_bio; struct mapped_device *md = io->md; blk_status_t io_error; bool requeued; requeued = dm_handle_requeue(io, first_stage); if (requeued && first_stage) return; io_error = io->status; if (dm_io_flagged(io, DM_IO_ACCOUNTED)) dm_end_io_acct(io); else if (!io_error) { /* * Must handle target that DM_MAPIO_SUBMITTED only to * then bio_endio() rather than dm_submit_bio_remap() */ __dm_start_io_acct(io); dm_end_io_acct(io); } free_io(io); smp_wmb(); this_cpu_dec(*md->pending_io); /* nudge anyone waiting on suspend queue */ if (unlikely(wq_has_sleeper(&md->wait))) wake_up(&md->wait); /* Return early if the original bio was requeued */ if (requeued) return; if (bio_is_flush_with_data(bio)) { /* * Preflush done for flush with data, reissue * without REQ_PREFLUSH. */ bio->bi_opf &= ~REQ_PREFLUSH; queue_io(md, bio); } else { /* done with normal IO or empty flush */ if (io_error) bio->bi_status = io_error; bio_endio(bio); } } static void dm_wq_requeue_work(struct work_struct *work) { struct mapped_device *md = container_of(work, struct mapped_device, requeue_work); unsigned long flags; struct dm_io *io; /* reuse deferred lock to simplify dm_handle_requeue */ spin_lock_irqsave(&md->deferred_lock, flags); io = md->requeue_list; md->requeue_list = NULL; spin_unlock_irqrestore(&md->deferred_lock, flags); while (io) { struct dm_io *next = io->next; dm_io_rewind(io, &md->disk->bio_split); io->next = NULL; __dm_io_complete(io, false); io = next; } } /* * Two staged requeue: * * 1) io->orig_bio points to the real original bio, and the part mapped to * this io must be requeued, instead of other parts of the original bio. * * 2) io->orig_bio points to new cloned bio which matches the requeued dm_io. */ static void dm_io_complete(struct dm_io *io) { bool first_requeue; /* * Only dm_io that has been split needs two stage requeue, otherwise * we may run into long bio clone chain during suspend and OOM could * be triggered. * * Also flush data dm_io won't be marked as DM_IO_WAS_SPLIT, so they * also aren't handled via the first stage requeue. */ if (dm_io_flagged(io, DM_IO_WAS_SPLIT)) first_requeue = true; else first_requeue = false; __dm_io_complete(io, first_requeue); } /* * Decrements the number of outstanding ios that a bio has been * cloned into, completing the original io if necc. */ static inline void __dm_io_dec_pending(struct dm_io *io) { if (atomic_dec_and_test(&io->io_count)) dm_io_complete(io); } static void dm_io_set_error(struct dm_io *io, blk_status_t error) { unsigned long flags; /* Push-back supersedes any I/O errors */ spin_lock_irqsave(&io->lock, flags); if (!(io->status == BLK_STS_DM_REQUEUE && __noflush_suspending(io->md))) { io->status = error; } spin_unlock_irqrestore(&io->lock, flags); } static void dm_io_dec_pending(struct dm_io *io, blk_status_t error) { if (unlikely(error)) dm_io_set_error(io, error); __dm_io_dec_pending(io); } void disable_discard(struct mapped_device *md) { struct queue_limits *limits = dm_get_queue_limits(md); /* device doesn't really support DISCARD, disable it */ limits->max_discard_sectors = 0; } void disable_write_zeroes(struct mapped_device *md) { struct queue_limits *limits = dm_get_queue_limits(md); /* device doesn't really support WRITE ZEROES, disable it */ limits->max_write_zeroes_sectors = 0; } static bool swap_bios_limit(struct dm_target *ti, struct bio *bio) { return unlikely((bio->bi_opf & REQ_SWAP) != 0) && unlikely(ti->limit_swap_bios); } static void clone_endio(struct bio *bio) { blk_status_t error = bio->bi_status; struct dm_target_io *tio = clone_to_tio(bio); struct dm_target *ti = tio->ti; dm_endio_fn endio = ti->type->end_io; struct dm_io *io = tio->io; struct mapped_device *md = io->md; if (unlikely(error == BLK_STS_TARGET)) { if (bio_op(bio) == REQ_OP_DISCARD && !bdev_max_discard_sectors(bio->bi_bdev)) disable_discard(md); else if (bio_op(bio) == REQ_OP_WRITE_ZEROES && !bdev_write_zeroes_sectors(bio->bi_bdev)) disable_write_zeroes(md); } if (static_branch_unlikely(&zoned_enabled) && unlikely(bdev_is_zoned(bio->bi_bdev))) dm_zone_endio(io, bio); if (endio) { int r = endio(ti, bio, &error); switch (r) { case DM_ENDIO_REQUEUE: if (static_branch_unlikely(&zoned_enabled)) { /* * Requeuing writes to a sequential zone of a zoned * target will break the sequential write pattern: * fail such IO. */ if (WARN_ON_ONCE(dm_is_zone_write(md, bio))) error = BLK_STS_IOERR; else error = BLK_STS_DM_REQUEUE; } else error = BLK_STS_DM_REQUEUE; fallthrough; case DM_ENDIO_DONE: break; case DM_ENDIO_INCOMPLETE: /* The target will handle the io */ return; default: DMCRIT("unimplemented target endio return value: %d", r); BUG(); } } if (static_branch_unlikely(&swap_bios_enabled) && unlikely(swap_bios_limit(ti, bio))) up(&md->swap_bios_semaphore); free_tio(bio); dm_io_dec_pending(io, error); } /* * Return maximum size of I/O possible at the supplied sector up to the current * target boundary. */ static inline sector_t max_io_len_target_boundary(struct dm_target *ti, sector_t target_offset) { return ti->len - target_offset; } static sector_t max_io_len(struct dm_target *ti, sector_t sector) { sector_t target_offset = dm_target_offset(ti, sector); sector_t len = max_io_len_target_boundary(ti, target_offset); /* * Does the target need to split IO even further? * - varied (per target) IO splitting is a tenet of DM; this * explains why stacked chunk_sectors based splitting via * bio_split_to_limits() isn't possible here. */ if (!ti->max_io_len) return len; return min_t(sector_t, len, min(queue_max_sectors(ti->table->md->queue), blk_chunk_sectors_left(target_offset, ti->max_io_len))); } int dm_set_target_max_io_len(struct dm_target *ti, sector_t len) { if (len > UINT_MAX) { DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)", (unsigned long long)len, UINT_MAX); ti->error = "Maximum size of target IO is too large"; return -EINVAL; } ti->max_io_len = (uint32_t) len; return 0; } EXPORT_SYMBOL_GPL(dm_set_target_max_io_len); static struct dm_target *dm_dax_get_live_target(struct mapped_device *md, sector_t sector, int *srcu_idx) __acquires(md->io_barrier) { struct dm_table *map; struct dm_target *ti; map = dm_get_live_table(md, srcu_idx); if (!map) return NULL; ti = dm_table_find_target(map, sector); if (!ti) return NULL; return ti; } static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, enum dax_access_mode mode, void **kaddr, pfn_t *pfn) { struct mapped_device *md = dax_get_private(dax_dev); sector_t sector = pgoff * PAGE_SECTORS; struct dm_target *ti; long len, ret = -EIO; int srcu_idx; ti = dm_dax_get_live_target(md, sector, &srcu_idx); if (!ti) goto out; if (!ti->type->direct_access) goto out; len = max_io_len(ti, sector) / PAGE_SECTORS; if (len < 1) goto out; nr_pages = min(len, nr_pages); ret = ti->type->direct_access(ti, pgoff, nr_pages, mode, kaddr, pfn); out: dm_put_live_table(md, srcu_idx); return ret; } static int dm_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, size_t nr_pages) { struct mapped_device *md = dax_get_private(dax_dev); sector_t sector = pgoff * PAGE_SECTORS; struct dm_target *ti; int ret = -EIO; int srcu_idx; ti = dm_dax_get_live_target(md, sector, &srcu_idx); if (!ti) goto out; if (WARN_ON(!ti->type->dax_zero_page_range)) { /* * ->zero_page_range() is mandatory dax operation. If we are * here, something is wrong. */ goto out; } ret = ti->type->dax_zero_page_range(ti, pgoff, nr_pages); out: dm_put_live_table(md, srcu_idx); return ret; } static size_t dm_dax_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i) { struct mapped_device *md = dax_get_private(dax_dev); sector_t sector = pgoff * PAGE_SECTORS; struct dm_target *ti; int srcu_idx; long ret = 0; ti = dm_dax_get_live_target(md, sector, &srcu_idx); if (!ti || !ti->type->dax_recovery_write) goto out; ret = ti->type->dax_recovery_write(ti, pgoff, addr, bytes, i); out: dm_put_live_table(md, srcu_idx); return ret; } /* * A target may call dm_accept_partial_bio only from the map routine. It is * allowed for all bio types except REQ_PREFLUSH, REQ_OP_ZONE_* zone management * operations, REQ_OP_ZONE_APPEND (zone append writes) and any bio serviced by * __send_duplicate_bios(). * * dm_accept_partial_bio informs the dm that the target only wants to process * additional n_sectors sectors of the bio and the rest of the data should be * sent in a next bio. * * A diagram that explains the arithmetics: * +--------------------+---------------+-------+ * | 1 | 2 | 3 | * +--------------------+---------------+-------+ * * <-------------- *tio->len_ptr ---------------> * <----- bio_sectors -----> * <-- n_sectors --> * * Region 1 was already iterated over with bio_advance or similar function. * (it may be empty if the target doesn't use bio_advance) * Region 2 is the remaining bio size that the target wants to process. * (it may be empty if region 1 is non-empty, although there is no reason * to make it empty) * The target requires that region 3 is to be sent in the next bio. * * If the target wants to receive multiple copies of the bio (via num_*bios, etc), * the partially processed part (the sum of regions 1+2) must be the same for all * copies of the bio. */ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors) { struct dm_target_io *tio = clone_to_tio(bio); struct dm_io *io = tio->io; unsigned bio_sectors = bio_sectors(bio); BUG_ON(dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO)); BUG_ON(op_is_zone_mgmt(bio_op(bio))); BUG_ON(bio_op(bio) == REQ_OP_ZONE_APPEND); BUG_ON(bio_sectors > *tio->len_ptr); BUG_ON(n_sectors > bio_sectors); *tio->len_ptr -= bio_sectors - n_sectors; bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT; /* * __split_and_process_bio() may have already saved mapped part * for accounting but it is being reduced so update accordingly. */ dm_io_set_flag(io, DM_IO_WAS_SPLIT); io->sectors = n_sectors; io->sector_offset = bio_sectors(io->orig_bio); } EXPORT_SYMBOL_GPL(dm_accept_partial_bio); /* * @clone: clone bio that DM core passed to target's .map function * @tgt_clone: clone of @clone bio that target needs submitted * * Targets should use this interface to submit bios they take * ownership of when returning DM_MAPIO_SUBMITTED. * * Target should also enable ti->accounts_remapped_io */ void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone) { struct dm_target_io *tio = clone_to_tio(clone); struct dm_io *io = tio->io; /* establish bio that will get submitted */ if (!tgt_clone) tgt_clone = clone; /* * Account io->origin_bio to DM dev on behalf of target * that took ownership of IO with DM_MAPIO_SUBMITTED. */ dm_start_io_acct(io, clone); trace_block_bio_remap(tgt_clone, disk_devt(io->md->disk), tio->old_sector); submit_bio_noacct(tgt_clone); } EXPORT_SYMBOL_GPL(dm_submit_bio_remap); static noinline void __set_swap_bios_limit(struct mapped_device *md, int latch) { mutex_lock(&md->swap_bios_lock); while (latch < md->swap_bios) { cond_resched(); down(&md->swap_bios_semaphore); md->swap_bios--; } while (latch > md->swap_bios) { cond_resched(); up(&md->swap_bios_semaphore); md->swap_bios++; } mutex_unlock(&md->swap_bios_lock); } static void __map_bio(struct bio *clone) { struct dm_target_io *tio = clone_to_tio(clone); struct dm_target *ti = tio->ti; struct dm_io *io = tio->io; struct mapped_device *md = io->md; int r; clone->bi_end_io = clone_endio; /* * Map the clone. */ tio->old_sector = clone->bi_iter.bi_sector; if (static_branch_unlikely(&swap_bios_enabled) && unlikely(swap_bios_limit(ti, clone))) { int latch = get_swap_bios(); if (unlikely(latch != md->swap_bios)) __set_swap_bios_limit(md, latch); down(&md->swap_bios_semaphore); } if (static_branch_unlikely(&zoned_enabled)) { /* * Check if the IO needs a special mapping due to zone append * emulation on zoned target. In this case, dm_zone_map_bio() * calls the target map operation. */ if (unlikely(dm_emulate_zone_append(md))) r = dm_zone_map_bio(tio); else r = ti->type->map(ti, clone); } else r = ti->type->map(ti, clone); switch (r) { case DM_MAPIO_SUBMITTED: /* target has assumed ownership of this io */ if (!ti->accounts_remapped_io) dm_start_io_acct(io, clone); break; case DM_MAPIO_REMAPPED: dm_submit_bio_remap(clone, NULL); break; case DM_MAPIO_KILL: case DM_MAPIO_REQUEUE: if (static_branch_unlikely(&swap_bios_enabled) && unlikely(swap_bios_limit(ti, clone))) up(&md->swap_bios_semaphore); free_tio(clone); if (r == DM_MAPIO_KILL) dm_io_dec_pending(io, BLK_STS_IOERR); else dm_io_dec_pending(io, BLK_STS_DM_REQUEUE); break; default: DMCRIT("unimplemented target map return value: %d", r); BUG(); } } static void setup_split_accounting(struct clone_info *ci, unsigned len) { struct dm_io *io = ci->io; if (ci->sector_count > len) { /* * Split needed, save the mapped part for accounting. * NOTE: dm_accept_partial_bio() will update accordingly. */ dm_io_set_flag(io, DM_IO_WAS_SPLIT); io->sectors = len; io->sector_offset = bio_sectors(ci->bio); } } static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci, struct dm_target *ti, unsigned num_bios) { struct bio *bio; int try; for (try = 0; try < 2; try++) { int bio_nr; if (try) mutex_lock(&ci->io->md->table_devices_lock); for (bio_nr = 0; bio_nr < num_bios; bio_nr++) { bio = alloc_tio(ci, ti, bio_nr, NULL, try ? GFP_NOIO : GFP_NOWAIT); if (!bio) break; bio_list_add(blist, bio); } if (try) mutex_unlock(&ci->io->md->table_devices_lock); if (bio_nr == num_bios) return; while ((bio = bio_list_pop(blist))) free_tio(bio); } } static int __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti, unsigned int num_bios, unsigned *len) { struct bio_list blist = BIO_EMPTY_LIST; struct bio *clone; unsigned int ret = 0; switch (num_bios) { case 0: break; case 1: if (len) setup_split_accounting(ci, *len); clone = alloc_tio(ci, ti, 0, len, GFP_NOIO); __map_bio(clone); ret = 1; break; default: /* dm_accept_partial_bio() is not supported with shared tio->len_ptr */ alloc_multiple_bios(&blist, ci, ti, num_bios); while ((clone = bio_list_pop(&blist))) { dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO); __map_bio(clone); ret += 1; } break; } return ret; } static void __send_empty_flush(struct clone_info *ci) { struct dm_table *t = ci->map; struct bio flush_bio; /* * Use an on-stack bio for this, it's safe since we don't * need to reference it after submit. It's just used as * the basis for the clone(s). */ bio_init(&flush_bio, ci->io->md->disk->part0, NULL, 0, REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC); ci->bio = &flush_bio; ci->sector_count = 0; ci->io->tio.clone.bi_iter.bi_size = 0; for (unsigned int i = 0; i < t->num_targets; i++) { unsigned int bios; struct dm_target *ti = dm_table_get_target(t, i); atomic_add(ti->num_flush_bios, &ci->io->io_count); bios = __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL); atomic_sub(ti->num_flush_bios - bios, &ci->io->io_count); } /* * alloc_io() takes one extra reference for submission, so the * reference won't reach 0 without the following subtraction */ atomic_sub(1, &ci->io->io_count); bio_uninit(ci->bio); } static void __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti, unsigned num_bios) { unsigned len; unsigned int bios; len = min_t(sector_t, ci->sector_count, max_io_len_target_boundary(ti, dm_target_offset(ti, ci->sector))); atomic_add(num_bios, &ci->io->io_count); bios = __send_duplicate_bios(ci, ti, num_bios, &len); /* * alloc_io() takes one extra reference for submission, so the * reference won't reach 0 without the following (+1) subtraction */ atomic_sub(num_bios - bios + 1, &ci->io->io_count); ci->sector += len; ci->sector_count -= len; } static bool is_abnormal_io(struct bio *bio) { enum req_op op = bio_op(bio); if (op != REQ_OP_READ && op != REQ_OP_WRITE && op != REQ_OP_FLUSH) { switch (op) { case REQ_OP_DISCARD: case REQ_OP_SECURE_ERASE: case REQ_OP_WRITE_ZEROES: return true; default: break; } } return false; } static blk_status_t __process_abnormal_io(struct clone_info *ci, struct dm_target *ti) { unsigned num_bios = 0; switch (bio_op(ci->bio)) { case REQ_OP_DISCARD: num_bios = ti->num_discard_bios; break; case REQ_OP_SECURE_ERASE: num_bios = ti->num_secure_erase_bios; break; case REQ_OP_WRITE_ZEROES: num_bios = ti->num_write_zeroes_bios; break; default: break; } /* * Even though the device advertised support for this type of * request, that does not mean every target supports it, and * reconfiguration might also have changed that since the * check was performed. */ if (unlikely(!num_bios)) return BLK_STS_NOTSUPP; __send_changing_extent_only(ci, ti, num_bios); return BLK_STS_OK; } /* * Reuse ->bi_private as dm_io list head for storing all dm_io instances * associated with this bio, and this bio's bi_private needs to be * stored in dm_io->data before the reuse. * * bio->bi_private is owned by fs or upper layer, so block layer won't * touch it after splitting. Meantime it won't be changed by anyone after * bio is submitted. So this reuse is safe. */ static inline struct dm_io **dm_poll_list_head(struct bio *bio) { return (struct dm_io **)&bio->bi_private; } static void dm_queue_poll_io(struct bio *bio, struct dm_io *io) { struct dm_io **head = dm_poll_list_head(bio); if (!(bio->bi_opf & REQ_DM_POLL_LIST)) { bio->bi_opf |= REQ_DM_POLL_LIST; /* * Save .bi_private into dm_io, so that we can reuse * .bi_private as dm_io list head for storing dm_io list */ io->data = bio->bi_private; /* tell block layer to poll for completion */ bio->bi_cookie = ~BLK_QC_T_NONE; io->next = NULL; } else { /* * bio recursed due to split, reuse original poll list, * and save bio->bi_private too. */ io->data = (*head)->data; io->next = *head; } *head = io; } /* * Select the correct strategy for processing a non-flush bio. */ static blk_status_t __split_and_process_bio(struct clone_info *ci) { struct bio *clone; struct dm_target *ti; unsigned len; ti = dm_table_find_target(ci->map, ci->sector); if (unlikely(!ti)) return BLK_STS_IOERR; if (unlikely((ci->bio->bi_opf & REQ_NOWAIT) != 0) && unlikely(!dm_target_supports_nowait(ti->type))) return BLK_STS_NOTSUPP; if (unlikely(ci->is_abnormal_io)) return __process_abnormal_io(ci, ti); /* * Only support bio polling for normal IO, and the target io is * exactly inside the dm_io instance (verified in dm_poll_dm_io) */ ci->submit_as_polled = !!(ci->bio->bi_opf & REQ_POLLED); len = min_t(sector_t, max_io_len(ti, ci->sector), ci->sector_count); setup_split_accounting(ci, len); clone = alloc_tio(ci, ti, 0, &len, GFP_NOIO); __map_bio(clone); ci->sector += len; ci->sector_count -= len; return BLK_STS_OK; } static void init_clone_info(struct clone_info *ci, struct mapped_device *md, struct dm_table *map, struct bio *bio, bool is_abnormal) { ci->map = map; ci->io = alloc_io(md, bio); ci->bio = bio; ci->is_abnormal_io = is_abnormal; ci->submit_as_polled = false; ci->sector = bio->bi_iter.bi_sector; ci->sector_count = bio_sectors(bio); /* Shouldn't happen but sector_count was being set to 0 so... */ if (static_branch_unlikely(&zoned_enabled) && WARN_ON_ONCE(op_is_zone_mgmt(bio_op(bio)) && ci->sector_count)) ci->sector_count = 0; } /* * Entry point to split a bio into clones and submit them to the targets. */ static void dm_split_and_process_bio(struct mapped_device *md, struct dm_table *map, struct bio *bio) { struct clone_info ci; struct dm_io *io; blk_status_t error = BLK_STS_OK; bool is_abnormal; is_abnormal = is_abnormal_io(bio); if (unlikely(is_abnormal)) { /* * Use bio_split_to_limits() for abnormal IO (e.g. discard, etc) * otherwise associated queue_limits won't be imposed. */ bio = bio_split_to_limits(bio); } init_clone_info(&ci, md, map, bio, is_abnormal); io = ci.io; if (bio->bi_opf & REQ_PREFLUSH) { __send_empty_flush(&ci); /* dm_io_complete submits any data associated with flush */ goto out; } error = __split_and_process_bio(&ci); if (error || !ci.sector_count) goto out; /* * Remainder must be passed to submit_bio_noacct() so it gets handled * *after* bios already submitted have been completely processed. */ bio_trim(bio, io->sectors, ci.sector_count); trace_block_split(bio, bio->bi_iter.bi_sector); bio_inc_remaining(bio); submit_bio_noacct(bio); out: /* * Drop the extra reference count for non-POLLED bio, and hold one * reference for POLLED bio, which will be released in dm_poll_bio * * Add every dm_io instance into the dm_io list head which is stored * in bio->bi_private, so that dm_poll_bio can poll them all. */ if (error || !ci.submit_as_polled) { /* * In case of submission failure, the extra reference for * submitting io isn't consumed yet */ if (error) atomic_dec(&io->io_count); dm_io_dec_pending(io, error); } else dm_queue_poll_io(bio, io); } static void dm_submit_bio(struct bio *bio) { struct mapped_device *md = bio->bi_bdev->bd_disk->private_data; int srcu_idx; struct dm_table *map; blk_opf_t bio_opf = bio->bi_opf; map = dm_get_live_table_bio(md, &srcu_idx, bio_opf); /* If suspended, or map not yet available, queue this IO for later */ if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) || unlikely(!map)) { if (bio->bi_opf & REQ_NOWAIT) bio_wouldblock_error(bio); else if (bio->bi_opf & REQ_RAHEAD) bio_io_error(bio); else queue_io(md, bio); goto out; } dm_split_and_process_bio(md, map, bio); out: dm_put_live_table_bio(md, srcu_idx, bio_opf); } static bool dm_poll_dm_io(struct dm_io *io, struct io_comp_batch *iob, unsigned int flags) { WARN_ON_ONCE(!dm_tio_is_normal(&io->tio)); /* don't poll if the mapped io is done */ if (atomic_read(&io->io_count) > 1) bio_poll(&io->tio.clone, iob, flags); /* bio_poll holds the last reference */ return atomic_read(&io->io_count) == 1; } static int dm_poll_bio(struct bio *bio, struct io_comp_batch *iob, unsigned int flags) { struct dm_io **head = dm_poll_list_head(bio); struct dm_io *list = *head; struct dm_io *tmp = NULL; struct dm_io *curr, *next; /* Only poll normal bio which was marked as REQ_DM_POLL_LIST */ if (!(bio->bi_opf & REQ_DM_POLL_LIST)) return 0; WARN_ON_ONCE(!list); /* * Restore .bi_private before possibly completing dm_io. * * bio_poll() is only possible once @bio has been completely * submitted via submit_bio_noacct()'s depth-first submission. * So there is no dm_queue_poll_io() race associated with * clearing REQ_DM_POLL_LIST here. */ bio->bi_opf &= ~REQ_DM_POLL_LIST; bio->bi_private = list->data; for (curr = list, next = curr->next; curr; curr = next, next = curr ? curr->next : NULL) { if (dm_poll_dm_io(curr, iob, flags)) { /* * clone_endio() has already occurred, so no * error handling is needed here. */ __dm_io_dec_pending(curr); } else { curr->next = tmp; tmp = curr; } } /* Not done? */ if (tmp) { bio->bi_opf |= REQ_DM_POLL_LIST; /* Reset bio->bi_private to dm_io list head */ *head = tmp; return 0; } return 1; } /*----------------------------------------------------------------- * An IDR is used to keep track of allocated minor numbers. *---------------------------------------------------------------*/ static void free_minor(int minor) { spin_lock(&_minor_lock); idr_remove(&_minor_idr, minor); spin_unlock(&_minor_lock); } /* * See if the device with a specific minor # is free. */ static int specific_minor(int minor) { int r; if (minor >= (1 << MINORBITS)) return -EINVAL; idr_preload(GFP_KERNEL); spin_lock(&_minor_lock); r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT); spin_unlock(&_minor_lock); idr_preload_end(); if (r < 0) return r == -ENOSPC ? -EBUSY : r; return 0; } static int next_free_minor(int *minor) { int r; idr_preload(GFP_KERNEL); spin_lock(&_minor_lock); r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT); spin_unlock(&_minor_lock); idr_preload_end(); if (r < 0) return r; *minor = r; return 0; } static const struct block_device_operations dm_blk_dops; static const struct block_device_operations dm_rq_blk_dops; static const struct dax_operations dm_dax_ops; static void dm_wq_work(struct work_struct *work); #ifdef CONFIG_BLK_INLINE_ENCRYPTION static void dm_queue_destroy_crypto_profile(struct request_queue *q) { dm_destroy_crypto_profile(q->crypto_profile); } #else /* CONFIG_BLK_INLINE_ENCRYPTION */ static inline void dm_queue_destroy_crypto_profile(struct request_queue *q) { } #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */ static void cleanup_mapped_device(struct mapped_device *md) { if (md->wq) destroy_workqueue(md->wq); dm_free_md_mempools(md->mempools); if (md->dax_dev) { dax_remove_host(md->disk); kill_dax(md->dax_dev); put_dax(md->dax_dev); md->dax_dev = NULL; } dm_cleanup_zoned_dev(md); if (md->disk) { spin_lock(&_minor_lock); md->disk->private_data = NULL; spin_unlock(&_minor_lock); if (dm_get_md_type(md) != DM_TYPE_NONE) { dm_sysfs_exit(md); del_gendisk(md->disk); } dm_queue_destroy_crypto_profile(md->queue); put_disk(md->disk); } if (md->pending_io) { free_percpu(md->pending_io); md->pending_io = NULL; } cleanup_srcu_struct(&md->io_barrier); mutex_destroy(&md->suspend_lock); mutex_destroy(&md->type_lock); mutex_destroy(&md->table_devices_lock); mutex_destroy(&md->swap_bios_lock); dm_mq_cleanup_mapped_device(md); } /* * Allocate and initialise a blank device with a given minor. */ static struct mapped_device *alloc_dev(int minor) { int r, numa_node_id = dm_get_numa_node(); struct mapped_device *md; void *old_md; md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id); if (!md) { DMERR("unable to allocate device, out of memory."); return NULL; } if (!try_module_get(THIS_MODULE)) goto bad_module_get; /* get a minor number for the dev */ if (minor == DM_ANY_MINOR) r = next_free_minor(&minor); else r = specific_minor(minor); if (r < 0) goto bad_minor; r = init_srcu_struct(&md->io_barrier); if (r < 0) goto bad_io_barrier; md->numa_node_id = numa_node_id; md->init_tio_pdu = false; md->type = DM_TYPE_NONE; mutex_init(&md->suspend_lock); mutex_init(&md->type_lock); mutex_init(&md->table_devices_lock); spin_lock_init(&md->deferred_lock); atomic_set(&md->holders, 1); atomic_set(&md->open_count, 0); atomic_set(&md->event_nr, 0); atomic_set(&md->uevent_seq, 0); INIT_LIST_HEAD(&md->uevent_list); INIT_LIST_HEAD(&md->table_devices); spin_lock_init(&md->uevent_lock); /* * default to bio-based until DM table is loaded and md->type * established. If request-based table is loaded: blk-mq will * override accordingly. */ md->disk = blk_alloc_disk(md->numa_node_id); if (!md->disk) goto bad; md->queue = md->disk->queue; init_waitqueue_head(&md->wait); INIT_WORK(&md->work, dm_wq_work); INIT_WORK(&md->requeue_work, dm_wq_requeue_work); init_waitqueue_head(&md->eventq); init_completion(&md->kobj_holder.completion); md->requeue_list = NULL; md->swap_bios = get_swap_bios(); sema_init(&md->swap_bios_semaphore, md->swap_bios); mutex_init(&md->swap_bios_lock); md->disk->major = _major; md->disk->first_minor = minor; md->disk->minors = 1; md->disk->flags |= GENHD_FL_NO_PART; md->disk->fops = &dm_blk_dops; md->disk->private_data = md; sprintf(md->disk->disk_name, "dm-%d", minor); if (IS_ENABLED(CONFIG_FS_DAX)) { md->dax_dev = alloc_dax(md, &dm_dax_ops); if (IS_ERR(md->dax_dev)) { md->dax_dev = NULL; goto bad; } set_dax_nocache(md->dax_dev); set_dax_nomc(md->dax_dev); if (dax_add_host(md->dax_dev, md->disk)) goto bad; } format_dev_t(md->name, MKDEV(_major, minor)); md->wq = alloc_workqueue("kdmflush/%s", WQ_MEM_RECLAIM, 0, md->name); if (!md->wq) goto bad; md->pending_io = alloc_percpu(unsigned long); if (!md->pending_io) goto bad; dm_stats_init(&md->stats); /* Populate the mapping, nobody knows we exist yet */ spin_lock(&_minor_lock); old_md = idr_replace(&_minor_idr, md, minor); spin_unlock(&_minor_lock); BUG_ON(old_md != MINOR_ALLOCED); return md; bad: cleanup_mapped_device(md); bad_io_barrier: free_minor(minor); bad_minor: module_put(THIS_MODULE); bad_module_get: kvfree(md); return NULL; } static void unlock_fs(struct mapped_device *md); static void free_dev(struct mapped_device *md) { int minor = MINOR(disk_devt(md->disk)); unlock_fs(md); cleanup_mapped_device(md); free_table_devices(&md->table_devices); dm_stats_cleanup(&md->stats); free_minor(minor); module_put(THIS_MODULE); kvfree(md); } /* * Bind a table to the device. */ static void event_callback(void *context) { unsigned long flags; LIST_HEAD(uevents); struct mapped_device *md = (struct mapped_device *) context; spin_lock_irqsave(&md->uevent_lock, flags); list_splice_init(&md->uevent_list, &uevents); spin_unlock_irqrestore(&md->uevent_lock, flags); dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); atomic_inc(&md->event_nr); wake_up(&md->eventq); dm_issue_global_event(); } /* * Returns old map, which caller must destroy. */ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, struct queue_limits *limits) { struct dm_table *old_map; sector_t size; int ret; lockdep_assert_held(&md->suspend_lock); size = dm_table_get_size(t); /* * Wipe any geometry if the size of the table changed. */ if (size != dm_get_size(md)) memset(&md->geometry, 0, sizeof(md->geometry)); if (!get_capacity(md->disk)) set_capacity(md->disk, size); else set_capacity_and_notify(md->disk, size); dm_table_event_callback(t, event_callback, md); if (dm_table_request_based(t)) { /* * Leverage the fact that request-based DM targets are * immutable singletons - used to optimize dm_mq_queue_rq. */ md->immutable_target = dm_table_get_immutable_target(t); /* * There is no need to reload with request-based dm because the * size of front_pad doesn't change. * * Note for future: If you are to reload bioset, prep-ed * requests in the queue may refer to bio from the old bioset, * so you must walk through the queue to unprep. */ if (!md->mempools) { md->mempools = t->mempools; t->mempools = NULL; } } else { /* * The md may already have mempools that need changing. * If so, reload bioset because front_pad may have changed * because a different table was loaded. */ dm_free_md_mempools(md->mempools); md->mempools = t->mempools; t->mempools = NULL; } ret = dm_table_set_restrictions(t, md->queue, limits); if (ret) { old_map = ERR_PTR(ret); goto out; } old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); rcu_assign_pointer(md->map, (void *)t); md->immutable_target_type = dm_table_get_immutable_target_type(t); if (old_map) dm_sync_table(md); out: return old_map; } /* * Returns unbound table for the caller to free. */ static struct dm_table *__unbind(struct mapped_device *md) { struct dm_table *map = rcu_dereference_protected(md->map, 1); if (!map) return NULL; dm_table_event_callback(map, NULL, NULL); RCU_INIT_POINTER(md->map, NULL); dm_sync_table(md); return map; } /* * Constructor for a new device. */ int dm_create(int minor, struct mapped_device **result) { struct mapped_device *md; md = alloc_dev(minor); if (!md) return -ENXIO; dm_ima_reset_data(md); *result = md; return 0; } /* * Functions to manage md->type. * All are required to hold md->type_lock. */ void dm_lock_md_type(struct mapped_device *md) { mutex_lock(&md->type_lock); } void dm_unlock_md_type(struct mapped_device *md) { mutex_unlock(&md->type_lock); } void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type) { BUG_ON(!mutex_is_locked(&md->type_lock)); md->type = type; } enum dm_queue_mode dm_get_md_type(struct mapped_device *md) { return md->type; } struct target_type *dm_get_immutable_target_type(struct mapped_device *md) { return md->immutable_target_type; } /* * The queue_limits are only valid as long as you have a reference * count on 'md'. */ struct queue_limits *dm_get_queue_limits(struct mapped_device *md) { BUG_ON(!atomic_read(&md->holders)); return &md->queue->limits; } EXPORT_SYMBOL_GPL(dm_get_queue_limits); /* * Setup the DM device's queue based on md's type */ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t) { enum dm_queue_mode type = dm_table_get_type(t); struct queue_limits limits; int r; switch (type) { case DM_TYPE_REQUEST_BASED: md->disk->fops = &dm_rq_blk_dops; r = dm_mq_init_request_queue(md, t); if (r) { DMERR("Cannot initialize queue for request-based dm mapped device"); return r; } break; case DM_TYPE_BIO_BASED: case DM_TYPE_DAX_BIO_BASED: break; case DM_TYPE_NONE: WARN_ON_ONCE(true); break; } r = dm_calculate_queue_limits(t, &limits); if (r) { DMERR("Cannot calculate initial queue limits"); return r; } r = dm_table_set_restrictions(t, md->queue, &limits); if (r) return r; r = add_disk(md->disk); if (r) return r; r = dm_sysfs_init(md); if (r) { del_gendisk(md->disk); return r; } md->type = type; return 0; } struct mapped_device *dm_get_md(dev_t dev) { struct mapped_device *md; unsigned minor = MINOR(dev); if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) return NULL; spin_lock(&_minor_lock); md = idr_find(&_minor_idr, minor); if (!md || md == MINOR_ALLOCED || (MINOR(disk_devt(dm_disk(md))) != minor) || test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) { md = NULL; goto out; } dm_get(md); out: spin_unlock(&_minor_lock); return md; } EXPORT_SYMBOL_GPL(dm_get_md); void *dm_get_mdptr(struct mapped_device *md) { return md->interface_ptr; } void dm_set_mdptr(struct mapped_device *md, void *ptr) { md->interface_ptr = ptr; } void dm_get(struct mapped_device *md) { atomic_inc(&md->holders); BUG_ON(test_bit(DMF_FREEING, &md->flags)); } int dm_hold(struct mapped_device *md) { spin_lock(&_minor_lock); if (test_bit(DMF_FREEING, &md->flags)) { spin_unlock(&_minor_lock); return -EBUSY; } dm_get(md); spin_unlock(&_minor_lock); return 0; } EXPORT_SYMBOL_GPL(dm_hold); const char *dm_device_name(struct mapped_device *md) { return md->name; } EXPORT_SYMBOL_GPL(dm_device_name); static void __dm_destroy(struct mapped_device *md, bool wait) { struct dm_table *map; int srcu_idx; might_sleep(); spin_lock(&_minor_lock); idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md)))); set_bit(DMF_FREEING, &md->flags); spin_unlock(&_minor_lock); blk_mark_disk_dead(md->disk); /* * Take suspend_lock so that presuspend and postsuspend methods * do not race with internal suspend. */ mutex_lock(&md->suspend_lock); map = dm_get_live_table(md, &srcu_idx); if (!dm_suspended_md(md)) { dm_table_presuspend_targets(map); set_bit(DMF_SUSPENDED, &md->flags); set_bit(DMF_POST_SUSPENDING, &md->flags); dm_table_postsuspend_targets(map); } /* dm_put_live_table must be before msleep, otherwise deadlock is possible */ dm_put_live_table(md, srcu_idx); mutex_unlock(&md->suspend_lock); /* * Rare, but there may be I/O requests still going to complete, * for example. Wait for all references to disappear. * No one should increment the reference count of the mapped_device, * after the mapped_device state becomes DMF_FREEING. */ if (wait) while (atomic_read(&md->holders)) msleep(1); else if (atomic_read(&md->holders)) DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)", dm_device_name(md), atomic_read(&md->holders)); dm_table_destroy(__unbind(md)); free_dev(md); } void dm_destroy(struct mapped_device *md) { __dm_destroy(md, true); } void dm_destroy_immediate(struct mapped_device *md) { __dm_destroy(md, false); } void dm_put(struct mapped_device *md) { atomic_dec(&md->holders); } EXPORT_SYMBOL_GPL(dm_put); static bool dm_in_flight_bios(struct mapped_device *md) { int cpu; unsigned long sum = 0; for_each_possible_cpu(cpu) sum += *per_cpu_ptr(md->pending_io, cpu); return sum != 0; } static int dm_wait_for_bios_completion(struct mapped_device *md, unsigned int task_state) { int r = 0; DEFINE_WAIT(wait); while (true) { prepare_to_wait(&md->wait, &wait, task_state); if (!dm_in_flight_bios(md)) break; if (signal_pending_state(task_state, current)) { r = -EINTR; break; } io_schedule(); } finish_wait(&md->wait, &wait); smp_rmb(); return r; } static int dm_wait_for_completion(struct mapped_device *md, unsigned int task_state) { int r = 0; if (!queue_is_mq(md->queue)) return dm_wait_for_bios_completion(md, task_state); while (true) { if (!blk_mq_queue_inflight(md->queue)) break; if (signal_pending_state(task_state, current)) { r = -EINTR; break; } msleep(5); } return r; } /* * Process the deferred bios */ static void dm_wq_work(struct work_struct *work) { struct mapped_device *md = container_of(work, struct mapped_device, work); struct bio *bio; while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { spin_lock_irq(&md->deferred_lock); bio = bio_list_pop(&md->deferred); spin_unlock_irq(&md->deferred_lock); if (!bio) break; submit_bio_noacct(bio); } } static void dm_queue_flush(struct mapped_device *md) { clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); smp_mb__after_atomic(); queue_work(md->wq, &md->work); } /* * Swap in a new table, returning the old one for the caller to destroy. */ struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table) { struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL); struct queue_limits limits; int r; mutex_lock(&md->suspend_lock); /* device must be suspended */ if (!dm_suspended_md(md)) goto out; /* * If the new table has no data devices, retain the existing limits. * This helps multipath with queue_if_no_path if all paths disappear, * then new I/O is queued based on these limits, and then some paths * reappear. */ if (dm_table_has_no_data_devices(table)) { live_map = dm_get_live_table_fast(md); if (live_map) limits = md->queue->limits; dm_put_live_table_fast(md); } if (!live_map) { r = dm_calculate_queue_limits(table, &limits); if (r) { map = ERR_PTR(r); goto out; } } map = __bind(md, table, &limits); dm_issue_global_event(); out: mutex_unlock(&md->suspend_lock); return map; } /* * Functions to lock and unlock any filesystem running on the * device. */ static int lock_fs(struct mapped_device *md) { int r; WARN_ON(test_bit(DMF_FROZEN, &md->flags)); r = freeze_bdev(md->disk->part0); if (!r) set_bit(DMF_FROZEN, &md->flags); return r; } static void unlock_fs(struct mapped_device *md) { if (!test_bit(DMF_FROZEN, &md->flags)) return; thaw_bdev(md->disk->part0); clear_bit(DMF_FROZEN, &md->flags); } /* * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY * * If __dm_suspend returns 0, the device is completely quiescent * now. There is no request-processing activity. All new requests * are being added to md->deferred list. */ static int __dm_suspend(struct mapped_device *md, struct dm_table *map, unsigned suspend_flags, unsigned int task_state, int dmf_suspended_flag) { bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG; bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG; int r; lockdep_assert_held(&md->suspend_lock); /* * DMF_NOFLUSH_SUSPENDING must be set before presuspend. * This flag is cleared before dm_suspend returns. */ if (noflush) set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); else DMDEBUG("%s: suspending with flush", dm_device_name(md)); /* * This gets reverted if there's an error later and the targets * provide the .presuspend_undo hook. */ dm_table_presuspend_targets(map); /* * Flush I/O to the device. * Any I/O submitted after lock_fs() may not be flushed. * noflush takes precedence over do_lockfs. * (lock_fs() flushes I/Os and waits for them to complete.) */ if (!noflush && do_lockfs) { r = lock_fs(md); if (r) { dm_table_presuspend_undo_targets(map); return r; } } /* * Here we must make sure that no processes are submitting requests * to target drivers i.e. no one may be executing * dm_split_and_process_bio from dm_submit_bio. * * To get all processes out of dm_split_and_process_bio in dm_submit_bio, * we take the write lock. To prevent any process from reentering * dm_split_and_process_bio from dm_submit_bio and quiesce the thread * (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND and call * flush_workqueue(md->wq). */ set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); if (map) synchronize_srcu(&md->io_barrier); /* * Stop md->queue before flushing md->wq in case request-based * dm defers requests to md->wq from md->queue. */ if (dm_request_based(md)) dm_stop_queue(md->queue); flush_workqueue(md->wq); /* * At this point no more requests are entering target request routines. * We call dm_wait_for_completion to wait for all existing requests * to finish. */ r = dm_wait_for_completion(md, task_state); if (!r) set_bit(dmf_suspended_flag, &md->flags); if (noflush) clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); if (map) synchronize_srcu(&md->io_barrier); /* were we interrupted ? */ if (r < 0) { dm_queue_flush(md); if (dm_request_based(md)) dm_start_queue(md->queue); unlock_fs(md); dm_table_presuspend_undo_targets(map); /* pushback list is already flushed, so skip flush */ } return r; } /* * We need to be able to change a mapping table under a mounted * filesystem. For example we might want to move some data in * the background. Before the table can be swapped with * dm_bind_table, dm_suspend must be called to flush any in * flight bios and ensure that any further io gets deferred. */ /* * Suspend mechanism in request-based dm. * * 1. Flush all I/Os by lock_fs() if needed. * 2. Stop dispatching any I/O by stopping the request_queue. * 3. Wait for all in-flight I/Os to be completed or requeued. * * To abort suspend, start the request_queue. */ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) { struct dm_table *map = NULL; int r = 0; retry: mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING); if (dm_suspended_md(md)) { r = -EINVAL; goto out_unlock; } if (dm_suspended_internally_md(md)) { /* already internally suspended, wait for internal resume */ mutex_unlock(&md->suspend_lock); r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE); if (r) return r; goto retry; } map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED); if (r) goto out_unlock; set_bit(DMF_POST_SUSPENDING, &md->flags); dm_table_postsuspend_targets(map); clear_bit(DMF_POST_SUSPENDING, &md->flags); out_unlock: mutex_unlock(&md->suspend_lock); return r; } static int __dm_resume(struct mapped_device *md, struct dm_table *map) { if (map) { int r = dm_table_resume_targets(map); if (r) return r; } dm_queue_flush(md); /* * Flushing deferred I/Os must be done after targets are resumed * so that mapping of targets can work correctly. * Request-based dm is queueing the deferred I/Os in its request_queue. */ if (dm_request_based(md)) dm_start_queue(md->queue); unlock_fs(md); return 0; } int dm_resume(struct mapped_device *md) { int r; struct dm_table *map = NULL; retry: r = -EINVAL; mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING); if (!dm_suspended_md(md)) goto out; if (dm_suspended_internally_md(md)) { /* already internally suspended, wait for internal resume */ mutex_unlock(&md->suspend_lock); r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE); if (r) return r; goto retry; } map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); if (!map || !dm_table_get_size(map)) goto out; r = __dm_resume(md, map); if (r) goto out; clear_bit(DMF_SUSPENDED, &md->flags); out: mutex_unlock(&md->suspend_lock); return r; } /* * Internal suspend/resume works like userspace-driven suspend. It waits * until all bios finish and prevents issuing new bios to the target drivers. * It may be used only from the kernel. */ static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags) { struct dm_table *map = NULL; lockdep_assert_held(&md->suspend_lock); if (md->internal_suspend_count++) return; /* nested internal suspend */ if (dm_suspended_md(md)) { set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); return; /* nest suspend */ } map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); /* * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend * would require changing .presuspend to return an error -- avoid this * until there is a need for more elaborate variants of internal suspend. */ (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE, DMF_SUSPENDED_INTERNALLY); set_bit(DMF_POST_SUSPENDING, &md->flags); dm_table_postsuspend_targets(map); clear_bit(DMF_POST_SUSPENDING, &md->flags); } static void __dm_internal_resume(struct mapped_device *md) { BUG_ON(!md->internal_suspend_count); if (--md->internal_suspend_count) return; /* resume from nested internal suspend */ if (dm_suspended_md(md)) goto done; /* resume from nested suspend */ /* * NOTE: existing callers don't need to call dm_table_resume_targets * (which may fail -- so best to avoid it for now by passing NULL map) */ (void) __dm_resume(md, NULL); done: clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); smp_mb__after_atomic(); wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY); } void dm_internal_suspend_noflush(struct mapped_device *md) { mutex_lock(&md->suspend_lock); __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG); mutex_unlock(&md->suspend_lock); } EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush); void dm_internal_resume(struct mapped_device *md) { mutex_lock(&md->suspend_lock); __dm_internal_resume(md); mutex_unlock(&md->suspend_lock); } EXPORT_SYMBOL_GPL(dm_internal_resume); /* * Fast variants of internal suspend/resume hold md->suspend_lock, * which prevents interaction with userspace-driven suspend. */ void dm_internal_suspend_fast(struct mapped_device *md) { mutex_lock(&md->suspend_lock); if (dm_suspended_md(md) || dm_suspended_internally_md(md)) return; set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); synchronize_srcu(&md->io_barrier); flush_workqueue(md->wq); dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); } EXPORT_SYMBOL_GPL(dm_internal_suspend_fast); void dm_internal_resume_fast(struct mapped_device *md) { if (dm_suspended_md(md) || dm_suspended_internally_md(md)) goto done; dm_queue_flush(md); done: mutex_unlock(&md->suspend_lock); } EXPORT_SYMBOL_GPL(dm_internal_resume_fast); /*----------------------------------------------------------------- * Event notification. *---------------------------------------------------------------*/ int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, unsigned cookie) { int r; unsigned noio_flag; char udev_cookie[DM_COOKIE_LENGTH]; char *envp[] = { udev_cookie, NULL }; noio_flag = memalloc_noio_save(); if (!cookie) r = kobject_uevent(&disk_to_dev(md->disk)->kobj, action); else { snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u", DM_COOKIE_ENV_VAR_NAME, cookie); r = kobject_uevent_env(&disk_to_dev(md->disk)->kobj, action, envp); } memalloc_noio_restore(noio_flag); return r; } uint32_t dm_next_uevent_seq(struct mapped_device *md) { return atomic_add_return(1, &md->uevent_seq); } uint32_t dm_get_event_nr(struct mapped_device *md) { return atomic_read(&md->event_nr); } int dm_wait_event(struct mapped_device *md, int event_nr) { return wait_event_interruptible(md->eventq, (event_nr != atomic_read(&md->event_nr))); } void dm_uevent_add(struct mapped_device *md, struct list_head *elist) { unsigned long flags; spin_lock_irqsave(&md->uevent_lock, flags); list_add(elist, &md->uevent_list); spin_unlock_irqrestore(&md->uevent_lock, flags); } /* * The gendisk is only valid as long as you have a reference * count on 'md'. */ struct gendisk *dm_disk(struct mapped_device *md) { return md->disk; } EXPORT_SYMBOL_GPL(dm_disk); struct kobject *dm_kobject(struct mapped_device *md) { return &md->kobj_holder.kobj; } struct mapped_device *dm_get_from_kobject(struct kobject *kobj) { struct mapped_device *md; md = container_of(kobj, struct mapped_device, kobj_holder.kobj); spin_lock(&_minor_lock); if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) { md = NULL; goto out; } dm_get(md); out: spin_unlock(&_minor_lock); return md; } int dm_suspended_md(struct mapped_device *md) { return test_bit(DMF_SUSPENDED, &md->flags); } static int dm_post_suspending_md(struct mapped_device *md) { return test_bit(DMF_POST_SUSPENDING, &md->flags); } int dm_suspended_internally_md(struct mapped_device *md) { return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); } int dm_test_deferred_remove_flag(struct mapped_device *md) { return test_bit(DMF_DEFERRED_REMOVE, &md->flags); } int dm_suspended(struct dm_target *ti) { return dm_suspended_md(ti->table->md); } EXPORT_SYMBOL_GPL(dm_suspended); int dm_post_suspending(struct dm_target *ti) { return dm_post_suspending_md(ti->table->md); } EXPORT_SYMBOL_GPL(dm_post_suspending); int dm_noflush_suspending(struct dm_target *ti) { return __noflush_suspending(ti->table->md); } EXPORT_SYMBOL_GPL(dm_noflush_suspending); void dm_free_md_mempools(struct dm_md_mempools *pools) { if (!pools) return; bioset_exit(&pools->bs); bioset_exit(&pools->io_bs); kfree(pools); } struct dm_pr { u64 old_key; u64 new_key; u32 flags; bool abort; bool fail_early; int ret; enum pr_type type; }; static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn, struct dm_pr *pr) { struct mapped_device *md = bdev->bd_disk->private_data; struct dm_table *table; struct dm_target *ti; int ret = -ENOTTY, srcu_idx; table = dm_get_live_table(md, &srcu_idx); if (!table || !dm_table_get_size(table)) goto out; /* We only support devices that have a single target */ if (table->num_targets != 1) goto out; ti = dm_table_get_target(table, 0); if (dm_suspended_md(md)) { ret = -EAGAIN; goto out; } ret = -EINVAL; if (!ti->type->iterate_devices) goto out; ti->type->iterate_devices(ti, fn, pr); ret = 0; out: dm_put_live_table(md, srcu_idx); return ret; } /* * For register / unregister we need to manually call out to every path. */ static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { struct dm_pr *pr = data; const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; int ret; if (!ops || !ops->pr_register) { pr->ret = -EOPNOTSUPP; return -1; } ret = ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags); if (!ret) return 0; if (!pr->ret) pr->ret = ret; if (pr->fail_early) return -1; return 0; } static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key, u32 flags) { struct dm_pr pr = { .old_key = old_key, .new_key = new_key, .flags = flags, .fail_early = true, .ret = 0, }; int ret; ret = dm_call_pr(bdev, __dm_pr_register, &pr); if (ret) { /* Didn't even get to register a path */ return ret; } if (!pr.ret) return 0; ret = pr.ret; if (!new_key) return ret; /* unregister all paths if we failed to register any path */ pr.old_key = new_key; pr.new_key = 0; pr.flags = 0; pr.fail_early = false; (void) dm_call_pr(bdev, __dm_pr_register, &pr); return ret; } static int __dm_pr_reserve(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { struct dm_pr *pr = data; const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; if (!ops || !ops->pr_reserve) { pr->ret = -EOPNOTSUPP; return -1; } pr->ret = ops->pr_reserve(dev->bdev, pr->old_key, pr->type, pr->flags); if (!pr->ret) return -1; return 0; } static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type, u32 flags) { struct dm_pr pr = { .old_key = key, .flags = flags, .type = type, .fail_early = false, .ret = 0, }; int ret; ret = dm_call_pr(bdev, __dm_pr_reserve, &pr); if (ret) return ret; return pr.ret; } /* * If there is a non-All Registrants type of reservation, the release must be * sent down the holding path. For the cases where there is no reservation or * the path is not the holder the device will also return success, so we must * try each path to make sure we got the correct path. */ static int __dm_pr_release(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { struct dm_pr *pr = data; const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; if (!ops || !ops->pr_release) { pr->ret = -EOPNOTSUPP; return -1; } pr->ret = ops->pr_release(dev->bdev, pr->old_key, pr->type); if (pr->ret) return -1; return 0; } static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type) { struct dm_pr pr = { .old_key = key, .type = type, .fail_early = false, }; int ret; ret = dm_call_pr(bdev, __dm_pr_release, &pr); if (ret) return ret; return pr.ret; } static int __dm_pr_preempt(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { struct dm_pr *pr = data; const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; if (!ops || !ops->pr_preempt) { pr->ret = -EOPNOTSUPP; return -1; } pr->ret = ops->pr_preempt(dev->bdev, pr->old_key, pr->new_key, pr->type, pr->abort); if (!pr->ret) return -1; return 0; } static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key, enum pr_type type, bool abort) { struct dm_pr pr = { .new_key = new_key, .old_key = old_key, .type = type, .fail_early = false, }; int ret; ret = dm_call_pr(bdev, __dm_pr_preempt, &pr); if (ret) return ret; return pr.ret; } static int dm_pr_clear(struct block_device *bdev, u64 key) { struct mapped_device *md = bdev->bd_disk->private_data; const struct pr_ops *ops; int r, srcu_idx; r = dm_prepare_ioctl(md, &srcu_idx, &bdev); if (r < 0) goto out; ops = bdev->bd_disk->fops->pr_ops; if (ops && ops->pr_clear) r = ops->pr_clear(bdev, key); else r = -EOPNOTSUPP; out: dm_unprepare_ioctl(md, srcu_idx); return r; } static const struct pr_ops dm_pr_ops = { .pr_register = dm_pr_register, .pr_reserve = dm_pr_reserve, .pr_release = dm_pr_release, .pr_preempt = dm_pr_preempt, .pr_clear = dm_pr_clear, }; static const struct block_device_operations dm_blk_dops = { .submit_bio = dm_submit_bio, .poll_bio = dm_poll_bio, .open = dm_blk_open, .release = dm_blk_close, .ioctl = dm_blk_ioctl, .getgeo = dm_blk_getgeo, .report_zones = dm_blk_report_zones, .pr_ops = &dm_pr_ops, .owner = THIS_MODULE }; static const struct block_device_operations dm_rq_blk_dops = { .open = dm_blk_open, .release = dm_blk_close, .ioctl = dm_blk_ioctl, .getgeo = dm_blk_getgeo, .pr_ops = &dm_pr_ops, .owner = THIS_MODULE }; static const struct dax_operations dm_dax_ops = { .direct_access = dm_dax_direct_access, .zero_page_range = dm_dax_zero_page_range, .recovery_write = dm_dax_recovery_write, }; /* * module hooks */ module_init(dm_init); module_exit(dm_exit); module_param(major, uint, 0); MODULE_PARM_DESC(major, "The major number of the device mapper"); module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools"); module_param(dm_numa_node, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations"); module_param(swap_bios, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(swap_bios, "Maximum allowed inflight swap IOs"); MODULE_DESCRIPTION(DM_NAME " driver"); MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); MODULE_LICENSE("GPL");
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