From: Joe Thornber Date: Fri, 21 Oct 2016 14:06:40 +0000 (-0400) Subject: dm bio prison v2: new interface for the bio prison X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=742c8fdc31e820503f9267070311d894978d1349;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git dm bio prison v2: new interface for the bio prison The deferred set is gone and all methods have _v2 appended to the end of their names to allow for continued use of the original bio prison in DM thin-provisioning. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- diff --git a/drivers/md/Makefile b/drivers/md/Makefile index 3cbda1af87a0..d378b1db7852 100644 --- a/drivers/md/Makefile +++ b/drivers/md/Makefile @@ -11,6 +11,7 @@ dm-snapshot-y += dm-snap.o dm-exception-store.o dm-snap-transient.o \ dm-mirror-y += dm-raid1.o dm-log-userspace-y \ += dm-log-userspace-base.o dm-log-userspace-transfer.o +dm-bio-prison-y += dm-bio-prison-v1.o dm-bio-prison-v2.o dm-thin-pool-y += dm-thin.o dm-thin-metadata.o dm-cache-y += dm-cache-target.o dm-cache-metadata.o dm-cache-policy.o dm-cache-smq-y += dm-cache-policy-smq.o diff --git a/drivers/md/dm-bio-prison-v1.c b/drivers/md/dm-bio-prison-v1.c new file mode 100644 index 000000000000..ae7da2c30a57 --- /dev/null +++ b/drivers/md/dm-bio-prison-v1.c @@ -0,0 +1,464 @@ +/* + * Copyright (C) 2012 Red Hat, Inc. + * + * This file is released under the GPL. + */ + +#include "dm.h" +#include "dm-bio-prison-v1.h" +#include "dm-bio-prison-v2.h" + +#include +#include +#include +#include + +/*----------------------------------------------------------------*/ + +#define MIN_CELLS 1024 + +struct dm_bio_prison { + spinlock_t lock; + mempool_t *cell_pool; + struct rb_root cells; +}; + +static struct kmem_cache *_cell_cache; + +/*----------------------------------------------------------------*/ + +/* + * @nr_cells should be the number of cells you want in use _concurrently_. + * Don't confuse it with the number of distinct keys. + */ +struct dm_bio_prison *dm_bio_prison_create(void) +{ + struct dm_bio_prison *prison = kmalloc(sizeof(*prison), GFP_KERNEL); + + if (!prison) + return NULL; + + spin_lock_init(&prison->lock); + + prison->cell_pool = mempool_create_slab_pool(MIN_CELLS, _cell_cache); + if (!prison->cell_pool) { + kfree(prison); + return NULL; + } + + prison->cells = RB_ROOT; + + return prison; +} +EXPORT_SYMBOL_GPL(dm_bio_prison_create); + +void dm_bio_prison_destroy(struct dm_bio_prison *prison) +{ + mempool_destroy(prison->cell_pool); + kfree(prison); +} +EXPORT_SYMBOL_GPL(dm_bio_prison_destroy); + +struct dm_bio_prison_cell *dm_bio_prison_alloc_cell(struct dm_bio_prison *prison, gfp_t gfp) +{ + return mempool_alloc(prison->cell_pool, gfp); +} +EXPORT_SYMBOL_GPL(dm_bio_prison_alloc_cell); + +void dm_bio_prison_free_cell(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell) +{ + mempool_free(cell, prison->cell_pool); +} +EXPORT_SYMBOL_GPL(dm_bio_prison_free_cell); + +static void __setup_new_cell(struct dm_cell_key *key, + struct bio *holder, + struct dm_bio_prison_cell *cell) +{ + memcpy(&cell->key, key, sizeof(cell->key)); + cell->holder = holder; + bio_list_init(&cell->bios); +} + +static int cmp_keys(struct dm_cell_key *lhs, + struct dm_cell_key *rhs) +{ + if (lhs->virtual < rhs->virtual) + return -1; + + if (lhs->virtual > rhs->virtual) + return 1; + + if (lhs->dev < rhs->dev) + return -1; + + if (lhs->dev > rhs->dev) + return 1; + + if (lhs->block_end <= rhs->block_begin) + return -1; + + if (lhs->block_begin >= rhs->block_end) + return 1; + + return 0; +} + +static int __bio_detain(struct dm_bio_prison *prison, + struct dm_cell_key *key, + struct bio *inmate, + struct dm_bio_prison_cell *cell_prealloc, + struct dm_bio_prison_cell **cell_result) +{ + int r; + struct rb_node **new = &prison->cells.rb_node, *parent = NULL; + + while (*new) { + struct dm_bio_prison_cell *cell = + container_of(*new, struct dm_bio_prison_cell, node); + + r = cmp_keys(key, &cell->key); + + parent = *new; + if (r < 0) + new = &((*new)->rb_left); + else if (r > 0) + new = &((*new)->rb_right); + else { + if (inmate) + bio_list_add(&cell->bios, inmate); + *cell_result = cell; + return 1; + } + } + + __setup_new_cell(key, inmate, cell_prealloc); + *cell_result = cell_prealloc; + + rb_link_node(&cell_prealloc->node, parent, new); + rb_insert_color(&cell_prealloc->node, &prison->cells); + + return 0; +} + +static int bio_detain(struct dm_bio_prison *prison, + struct dm_cell_key *key, + struct bio *inmate, + struct dm_bio_prison_cell *cell_prealloc, + struct dm_bio_prison_cell **cell_result) +{ + int r; + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + r = __bio_detain(prison, key, inmate, cell_prealloc, cell_result); + spin_unlock_irqrestore(&prison->lock, flags); + + return r; +} + +int dm_bio_detain(struct dm_bio_prison *prison, + struct dm_cell_key *key, + struct bio *inmate, + struct dm_bio_prison_cell *cell_prealloc, + struct dm_bio_prison_cell **cell_result) +{ + return bio_detain(prison, key, inmate, cell_prealloc, cell_result); +} +EXPORT_SYMBOL_GPL(dm_bio_detain); + +int dm_get_cell(struct dm_bio_prison *prison, + struct dm_cell_key *key, + struct dm_bio_prison_cell *cell_prealloc, + struct dm_bio_prison_cell **cell_result) +{ + return bio_detain(prison, key, NULL, cell_prealloc, cell_result); +} +EXPORT_SYMBOL_GPL(dm_get_cell); + +/* + * @inmates must have been initialised prior to this call + */ +static void __cell_release(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell, + struct bio_list *inmates) +{ + rb_erase(&cell->node, &prison->cells); + + if (inmates) { + if (cell->holder) + bio_list_add(inmates, cell->holder); + bio_list_merge(inmates, &cell->bios); + } +} + +void dm_cell_release(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell, + struct bio_list *bios) +{ + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + __cell_release(prison, cell, bios); + spin_unlock_irqrestore(&prison->lock, flags); +} +EXPORT_SYMBOL_GPL(dm_cell_release); + +/* + * Sometimes we don't want the holder, just the additional bios. + */ +static void __cell_release_no_holder(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell, + struct bio_list *inmates) +{ + rb_erase(&cell->node, &prison->cells); + bio_list_merge(inmates, &cell->bios); +} + +void dm_cell_release_no_holder(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell, + struct bio_list *inmates) +{ + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + __cell_release_no_holder(prison, cell, inmates); + spin_unlock_irqrestore(&prison->lock, flags); +} +EXPORT_SYMBOL_GPL(dm_cell_release_no_holder); + +void dm_cell_error(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell, int error) +{ + struct bio_list bios; + struct bio *bio; + + bio_list_init(&bios); + dm_cell_release(prison, cell, &bios); + + while ((bio = bio_list_pop(&bios))) { + bio->bi_error = error; + bio_endio(bio); + } +} +EXPORT_SYMBOL_GPL(dm_cell_error); + +void dm_cell_visit_release(struct dm_bio_prison *prison, + void (*visit_fn)(void *, struct dm_bio_prison_cell *), + void *context, + struct dm_bio_prison_cell *cell) +{ + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + visit_fn(context, cell); + rb_erase(&cell->node, &prison->cells); + spin_unlock_irqrestore(&prison->lock, flags); +} +EXPORT_SYMBOL_GPL(dm_cell_visit_release); + +static int __promote_or_release(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell) +{ + if (bio_list_empty(&cell->bios)) { + rb_erase(&cell->node, &prison->cells); + return 1; + } + + cell->holder = bio_list_pop(&cell->bios); + return 0; +} + +int dm_cell_promote_or_release(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell) +{ + int r; + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + r = __promote_or_release(prison, cell); + spin_unlock_irqrestore(&prison->lock, flags); + + return r; +} +EXPORT_SYMBOL_GPL(dm_cell_promote_or_release); + +/*----------------------------------------------------------------*/ + +#define DEFERRED_SET_SIZE 64 + +struct dm_deferred_entry { + struct dm_deferred_set *ds; + unsigned count; + struct list_head work_items; +}; + +struct dm_deferred_set { + spinlock_t lock; + unsigned current_entry; + unsigned sweeper; + struct dm_deferred_entry entries[DEFERRED_SET_SIZE]; +}; + +struct dm_deferred_set *dm_deferred_set_create(void) +{ + int i; + struct dm_deferred_set *ds; + + ds = kmalloc(sizeof(*ds), GFP_KERNEL); + if (!ds) + return NULL; + + spin_lock_init(&ds->lock); + ds->current_entry = 0; + ds->sweeper = 0; + for (i = 0; i < DEFERRED_SET_SIZE; i++) { + ds->entries[i].ds = ds; + ds->entries[i].count = 0; + INIT_LIST_HEAD(&ds->entries[i].work_items); + } + + return ds; +} +EXPORT_SYMBOL_GPL(dm_deferred_set_create); + +void dm_deferred_set_destroy(struct dm_deferred_set *ds) +{ + kfree(ds); +} +EXPORT_SYMBOL_GPL(dm_deferred_set_destroy); + +struct dm_deferred_entry *dm_deferred_entry_inc(struct dm_deferred_set *ds) +{ + unsigned long flags; + struct dm_deferred_entry *entry; + + spin_lock_irqsave(&ds->lock, flags); + entry = ds->entries + ds->current_entry; + entry->count++; + spin_unlock_irqrestore(&ds->lock, flags); + + return entry; +} +EXPORT_SYMBOL_GPL(dm_deferred_entry_inc); + +static unsigned ds_next(unsigned index) +{ + return (index + 1) % DEFERRED_SET_SIZE; +} + +static void __sweep(struct dm_deferred_set *ds, struct list_head *head) +{ + while ((ds->sweeper != ds->current_entry) && + !ds->entries[ds->sweeper].count) { + list_splice_init(&ds->entries[ds->sweeper].work_items, head); + ds->sweeper = ds_next(ds->sweeper); + } + + if ((ds->sweeper == ds->current_entry) && !ds->entries[ds->sweeper].count) + list_splice_init(&ds->entries[ds->sweeper].work_items, head); +} + +void dm_deferred_entry_dec(struct dm_deferred_entry *entry, struct list_head *head) +{ + unsigned long flags; + + spin_lock_irqsave(&entry->ds->lock, flags); + BUG_ON(!entry->count); + --entry->count; + __sweep(entry->ds, head); + spin_unlock_irqrestore(&entry->ds->lock, flags); +} +EXPORT_SYMBOL_GPL(dm_deferred_entry_dec); + +/* + * Returns 1 if deferred or 0 if no pending items to delay job. + */ +int dm_deferred_set_add_work(struct dm_deferred_set *ds, struct list_head *work) +{ + int r = 1; + unsigned long flags; + unsigned next_entry; + + spin_lock_irqsave(&ds->lock, flags); + if ((ds->sweeper == ds->current_entry) && + !ds->entries[ds->current_entry].count) + r = 0; + else { + list_add(work, &ds->entries[ds->current_entry].work_items); + next_entry = ds_next(ds->current_entry); + if (!ds->entries[next_entry].count) + ds->current_entry = next_entry; + } + spin_unlock_irqrestore(&ds->lock, flags); + + return r; +} +EXPORT_SYMBOL_GPL(dm_deferred_set_add_work); + +/*----------------------------------------------------------------*/ + +static int __init dm_bio_prison_init_v1(void) +{ + _cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0); + if (!_cell_cache) + return -ENOMEM; + + return 0; +} + +static void dm_bio_prison_exit_v1(void) +{ + kmem_cache_destroy(_cell_cache); + _cell_cache = NULL; +} + +static int (*_inits[])(void) __initdata = { + dm_bio_prison_init_v1, + dm_bio_prison_init_v2, +}; + +static void (*_exits[])(void) = { + dm_bio_prison_exit_v1, + dm_bio_prison_exit_v2, +}; + +static int __init dm_bio_prison_init(void) +{ + const int count = ARRAY_SIZE(_inits); + + int r, i; + + 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_bio_prison_exit(void) +{ + int i = ARRAY_SIZE(_exits); + + while (i--) + _exits[i](); +} + +/* + * module hooks + */ +module_init(dm_bio_prison_init); +module_exit(dm_bio_prison_exit); + +MODULE_DESCRIPTION(DM_NAME " bio prison"); +MODULE_AUTHOR("Joe Thornber "); +MODULE_LICENSE("GPL"); diff --git a/drivers/md/dm-bio-prison-v1.h b/drivers/md/dm-bio-prison-v1.h new file mode 100644 index 000000000000..cddd4ac07e2c --- /dev/null +++ b/drivers/md/dm-bio-prison-v1.h @@ -0,0 +1,138 @@ +/* + * Copyright (C) 2011-2017 Red Hat, Inc. + * + * This file is released under the GPL. + */ + +#ifndef DM_BIO_PRISON_H +#define DM_BIO_PRISON_H + +#include "persistent-data/dm-block-manager.h" /* FIXME: for dm_block_t */ +#include "dm-thin-metadata.h" /* FIXME: for dm_thin_id */ + +#include +#include + +/*----------------------------------------------------------------*/ + +/* + * Sometimes we can't deal with a bio straight away. We put them in prison + * where they can't cause any mischief. Bios are put in a cell identified + * by a key, multiple bios can be in the same cell. When the cell is + * subsequently unlocked the bios become available. + */ +struct dm_bio_prison; + +/* + * Keys define a range of blocks within either a virtual or physical + * device. + */ +struct dm_cell_key { + int virtual; + dm_thin_id dev; + dm_block_t block_begin, block_end; +}; + +/* + * Treat this as opaque, only in header so callers can manage allocation + * themselves. + */ +struct dm_bio_prison_cell { + struct list_head user_list; /* for client use */ + struct rb_node node; + + struct dm_cell_key key; + struct bio *holder; + struct bio_list bios; +}; + +struct dm_bio_prison *dm_bio_prison_create(void); +void dm_bio_prison_destroy(struct dm_bio_prison *prison); + +/* + * These two functions just wrap a mempool. This is a transitory step: + * Eventually all bio prison clients should manage their own cell memory. + * + * Like mempool_alloc(), dm_bio_prison_alloc_cell() can only fail if called + * in interrupt context or passed GFP_NOWAIT. + */ +struct dm_bio_prison_cell *dm_bio_prison_alloc_cell(struct dm_bio_prison *prison, + gfp_t gfp); +void dm_bio_prison_free_cell(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell); + +/* + * Creates, or retrieves a cell that overlaps the given key. + * + * Returns 1 if pre-existing cell returned, zero if new cell created using + * @cell_prealloc. + */ +int dm_get_cell(struct dm_bio_prison *prison, + struct dm_cell_key *key, + struct dm_bio_prison_cell *cell_prealloc, + struct dm_bio_prison_cell **cell_result); + +/* + * An atomic op that combines retrieving or creating a cell, and adding a + * bio to it. + * + * Returns 1 if the cell was already held, 0 if @inmate is the new holder. + */ +int dm_bio_detain(struct dm_bio_prison *prison, + struct dm_cell_key *key, + struct bio *inmate, + struct dm_bio_prison_cell *cell_prealloc, + struct dm_bio_prison_cell **cell_result); + +void dm_cell_release(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell, + struct bio_list *bios); +void dm_cell_release_no_holder(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell, + struct bio_list *inmates); +void dm_cell_error(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell, int error); + +/* + * Visits the cell and then releases. Guarantees no new inmates are + * inserted between the visit and release. + */ +void dm_cell_visit_release(struct dm_bio_prison *prison, + void (*visit_fn)(void *, struct dm_bio_prison_cell *), + void *context, struct dm_bio_prison_cell *cell); + +/* + * Rather than always releasing the prisoners in a cell, the client may + * want to promote one of them to be the new holder. There is a race here + * though between releasing an empty cell, and other threads adding new + * inmates. So this function makes the decision with its lock held. + * + * This function can have two outcomes: + * i) An inmate is promoted to be the holder of the cell (return value of 0). + * ii) The cell has no inmate for promotion and is released (return value of 1). + */ +int dm_cell_promote_or_release(struct dm_bio_prison *prison, + struct dm_bio_prison_cell *cell); + +/*----------------------------------------------------------------*/ + +/* + * We use the deferred set to keep track of pending reads to shared blocks. + * We do this to ensure the new mapping caused by a write isn't performed + * until these prior reads have completed. Otherwise the insertion of the + * new mapping could free the old block that the read bios are mapped to. + */ + +struct dm_deferred_set; +struct dm_deferred_entry; + +struct dm_deferred_set *dm_deferred_set_create(void); +void dm_deferred_set_destroy(struct dm_deferred_set *ds); + +struct dm_deferred_entry *dm_deferred_entry_inc(struct dm_deferred_set *ds); +void dm_deferred_entry_dec(struct dm_deferred_entry *entry, struct list_head *head); +int dm_deferred_set_add_work(struct dm_deferred_set *ds, struct list_head *work); + +/*----------------------------------------------------------------*/ + +#endif diff --git a/drivers/md/dm-bio-prison-v2.c b/drivers/md/dm-bio-prison-v2.c new file mode 100644 index 000000000000..c9b11f799cd8 --- /dev/null +++ b/drivers/md/dm-bio-prison-v2.c @@ -0,0 +1,369 @@ +/* + * Copyright (C) 2012-2017 Red Hat, Inc. + * + * This file is released under the GPL. + */ + +#include "dm.h" +#include "dm-bio-prison-v2.h" + +#include +#include +#include +#include +#include + +/*----------------------------------------------------------------*/ + +#define MIN_CELLS 1024 + +struct dm_bio_prison_v2 { + struct workqueue_struct *wq; + + spinlock_t lock; + mempool_t *cell_pool; + struct rb_root cells; +}; + +static struct kmem_cache *_cell_cache; + +/*----------------------------------------------------------------*/ + +/* + * @nr_cells should be the number of cells you want in use _concurrently_. + * Don't confuse it with the number of distinct keys. + */ +struct dm_bio_prison_v2 *dm_bio_prison_create_v2(struct workqueue_struct *wq) +{ + struct dm_bio_prison_v2 *prison = kmalloc(sizeof(*prison), GFP_KERNEL); + + if (!prison) + return NULL; + + prison->wq = wq; + spin_lock_init(&prison->lock); + + prison->cell_pool = mempool_create_slab_pool(MIN_CELLS, _cell_cache); + if (!prison->cell_pool) { + kfree(prison); + return NULL; + } + + prison->cells = RB_ROOT; + + return prison; +} +EXPORT_SYMBOL_GPL(dm_bio_prison_create_v2); + +void dm_bio_prison_destroy_v2(struct dm_bio_prison_v2 *prison) +{ + mempool_destroy(prison->cell_pool); + kfree(prison); +} +EXPORT_SYMBOL_GPL(dm_bio_prison_destroy_v2); + +struct dm_bio_prison_cell_v2 *dm_bio_prison_alloc_cell_v2(struct dm_bio_prison_v2 *prison, gfp_t gfp) +{ + return mempool_alloc(prison->cell_pool, gfp); +} +EXPORT_SYMBOL_GPL(dm_bio_prison_alloc_cell_v2); + +void dm_bio_prison_free_cell_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell) +{ + mempool_free(cell, prison->cell_pool); +} +EXPORT_SYMBOL_GPL(dm_bio_prison_free_cell_v2); + +static void __setup_new_cell(struct dm_cell_key_v2 *key, + struct dm_bio_prison_cell_v2 *cell) +{ + memset(cell, 0, sizeof(*cell)); + memcpy(&cell->key, key, sizeof(cell->key)); + bio_list_init(&cell->bios); +} + +static int cmp_keys(struct dm_cell_key_v2 *lhs, + struct dm_cell_key_v2 *rhs) +{ + if (lhs->virtual < rhs->virtual) + return -1; + + if (lhs->virtual > rhs->virtual) + return 1; + + if (lhs->dev < rhs->dev) + return -1; + + if (lhs->dev > rhs->dev) + return 1; + + if (lhs->block_end <= rhs->block_begin) + return -1; + + if (lhs->block_begin >= rhs->block_end) + return 1; + + return 0; +} + +/* + * Returns true if node found, otherwise it inserts a new one. + */ +static bool __find_or_insert(struct dm_bio_prison_v2 *prison, + struct dm_cell_key_v2 *key, + struct dm_bio_prison_cell_v2 *cell_prealloc, + struct dm_bio_prison_cell_v2 **result) +{ + int r; + struct rb_node **new = &prison->cells.rb_node, *parent = NULL; + + while (*new) { + struct dm_bio_prison_cell_v2 *cell = + container_of(*new, struct dm_bio_prison_cell_v2, node); + + r = cmp_keys(key, &cell->key); + + parent = *new; + if (r < 0) + new = &((*new)->rb_left); + + else if (r > 0) + new = &((*new)->rb_right); + + else { + *result = cell; + return true; + } + } + + __setup_new_cell(key, cell_prealloc); + *result = cell_prealloc; + rb_link_node(&cell_prealloc->node, parent, new); + rb_insert_color(&cell_prealloc->node, &prison->cells); + + return false; +} + +static bool __get(struct dm_bio_prison_v2 *prison, + struct dm_cell_key_v2 *key, + unsigned lock_level, + struct bio *inmate, + struct dm_bio_prison_cell_v2 *cell_prealloc, + struct dm_bio_prison_cell_v2 **cell) +{ + if (__find_or_insert(prison, key, cell_prealloc, cell)) { + if ((*cell)->exclusive_lock) { + if (lock_level <= (*cell)->exclusive_level) { + bio_list_add(&(*cell)->bios, inmate); + return false; + } + } + + (*cell)->shared_count++; + + } else + (*cell)->shared_count = 1; + + return true; +} + +bool dm_cell_get_v2(struct dm_bio_prison_v2 *prison, + struct dm_cell_key_v2 *key, + unsigned lock_level, + struct bio *inmate, + struct dm_bio_prison_cell_v2 *cell_prealloc, + struct dm_bio_prison_cell_v2 **cell_result) +{ + int r; + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + r = __get(prison, key, lock_level, inmate, cell_prealloc, cell_result); + spin_unlock_irqrestore(&prison->lock, flags); + + return r; +} +EXPORT_SYMBOL_GPL(dm_cell_get_v2); + +static bool __put(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell) +{ + BUG_ON(!cell->shared_count); + cell->shared_count--; + + // FIXME: shared locks granted above the lock level could starve this + if (!cell->shared_count) { + if (cell->exclusive_lock){ + if (cell->quiesce_continuation) { + queue_work(prison->wq, cell->quiesce_continuation); + cell->quiesce_continuation = NULL; + } + } else { + rb_erase(&cell->node, &prison->cells); + return true; + } + } + + return false; +} + +bool dm_cell_put_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell) +{ + bool r; + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + r = __put(prison, cell); + spin_unlock_irqrestore(&prison->lock, flags); + + return r; +} +EXPORT_SYMBOL_GPL(dm_cell_put_v2); + +static int __lock(struct dm_bio_prison_v2 *prison, + struct dm_cell_key_v2 *key, + unsigned lock_level, + struct dm_bio_prison_cell_v2 *cell_prealloc, + struct dm_bio_prison_cell_v2 **cell_result) +{ + struct dm_bio_prison_cell_v2 *cell; + + if (__find_or_insert(prison, key, cell_prealloc, &cell)) { + if (cell->exclusive_lock) + return -EBUSY; + + cell->exclusive_lock = true; + cell->exclusive_level = lock_level; + *cell_result = cell; + + // FIXME: we don't yet know what level these shared locks + // were taken at, so have to quiesce them all. + return cell->shared_count > 0; + + } else { + cell = cell_prealloc; + cell->shared_count = 0; + cell->exclusive_lock = true; + cell->exclusive_level = lock_level; + *cell_result = cell; + } + + return 0; +} + +int dm_cell_lock_v2(struct dm_bio_prison_v2 *prison, + struct dm_cell_key_v2 *key, + unsigned lock_level, + struct dm_bio_prison_cell_v2 *cell_prealloc, + struct dm_bio_prison_cell_v2 **cell_result) +{ + int r; + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + r = __lock(prison, key, lock_level, cell_prealloc, cell_result); + spin_unlock_irqrestore(&prison->lock, flags); + + return r; +} +EXPORT_SYMBOL_GPL(dm_cell_lock_v2); + +static void __quiesce(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell, + struct work_struct *continuation) +{ + if (!cell->shared_count) + queue_work(prison->wq, continuation); + else + cell->quiesce_continuation = continuation; +} + +void dm_cell_quiesce_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell, + struct work_struct *continuation) +{ + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + __quiesce(prison, cell, continuation); + spin_unlock_irqrestore(&prison->lock, flags); +} +EXPORT_SYMBOL_GPL(dm_cell_quiesce_v2); + +static int __promote(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell, + unsigned new_lock_level) +{ + if (!cell->exclusive_lock) + return -EINVAL; + + cell->exclusive_level = new_lock_level; + return cell->shared_count > 0; +} + +int dm_cell_lock_promote_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell, + unsigned new_lock_level) +{ + int r; + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + r = __promote(prison, cell, new_lock_level); + spin_unlock_irqrestore(&prison->lock, flags); + + return r; +} +EXPORT_SYMBOL_GPL(dm_cell_lock_promote_v2); + +static bool __unlock(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell, + struct bio_list *bios) +{ + BUG_ON(!cell->exclusive_lock); + + bio_list_merge(bios, &cell->bios); + bio_list_init(&cell->bios); + + if (cell->shared_count) { + cell->exclusive_lock = 0; + return false; + } + + rb_erase(&cell->node, &prison->cells); + return true; +} + +bool dm_cell_unlock_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell, + struct bio_list *bios) +{ + bool r; + unsigned long flags; + + spin_lock_irqsave(&prison->lock, flags); + r = __unlock(prison, cell, bios); + spin_unlock_irqrestore(&prison->lock, flags); + + return r; +} +EXPORT_SYMBOL_GPL(dm_cell_unlock_v2); + +/*----------------------------------------------------------------*/ + +int __init dm_bio_prison_init_v2(void) +{ + _cell_cache = KMEM_CACHE(dm_bio_prison_cell_v2, 0); + if (!_cell_cache) + return -ENOMEM; + + return 0; +} + +void dm_bio_prison_exit_v2(void) +{ + kmem_cache_destroy(_cell_cache); + _cell_cache = NULL; +} diff --git a/drivers/md/dm-bio-prison-v2.h b/drivers/md/dm-bio-prison-v2.h new file mode 100644 index 000000000000..6e04234268db --- /dev/null +++ b/drivers/md/dm-bio-prison-v2.h @@ -0,0 +1,152 @@ +/* + * Copyright (C) 2011-2017 Red Hat, Inc. + * + * This file is released under the GPL. + */ + +#ifndef DM_BIO_PRISON_V2_H +#define DM_BIO_PRISON_V2_H + +#include "persistent-data/dm-block-manager.h" /* FIXME: for dm_block_t */ +#include "dm-thin-metadata.h" /* FIXME: for dm_thin_id */ + +#include +#include +#include + +/*----------------------------------------------------------------*/ + +int dm_bio_prison_init_v2(void); +void dm_bio_prison_exit_v2(void); + +/* + * Sometimes we can't deal with a bio straight away. We put them in prison + * where they can't cause any mischief. Bios are put in a cell identified + * by a key, multiple bios can be in the same cell. When the cell is + * subsequently unlocked the bios become available. + */ +struct dm_bio_prison_v2; + +/* + * Keys define a range of blocks within either a virtual or physical + * device. + */ +struct dm_cell_key_v2 { + int virtual; + dm_thin_id dev; + dm_block_t block_begin, block_end; +}; + +/* + * Treat this as opaque, only in header so callers can manage allocation + * themselves. + */ +struct dm_bio_prison_cell_v2 { + // FIXME: pack these + bool exclusive_lock; + unsigned exclusive_level; + unsigned shared_count; + struct work_struct *quiesce_continuation; + + struct rb_node node; + struct dm_cell_key_v2 key; + struct bio_list bios; +}; + +struct dm_bio_prison_v2 *dm_bio_prison_create_v2(struct workqueue_struct *wq); +void dm_bio_prison_destroy_v2(struct dm_bio_prison_v2 *prison); + +/* + * These two functions just wrap a mempool. This is a transitory step: + * Eventually all bio prison clients should manage their own cell memory. + * + * Like mempool_alloc(), dm_bio_prison_alloc_cell_v2() can only fail if called + * in interrupt context or passed GFP_NOWAIT. + */ +struct dm_bio_prison_cell_v2 *dm_bio_prison_alloc_cell_v2(struct dm_bio_prison_v2 *prison, + gfp_t gfp); +void dm_bio_prison_free_cell_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell); + +/* + * Shared locks have a bio associated with them. + * + * If the lock is granted the caller can continue to use the bio, and must + * call dm_cell_put_v2() to drop the reference count when finished using it. + * + * If the lock cannot be granted then the bio will be tracked within the + * cell, and later given to the holder of the exclusive lock. + * + * See dm_cell_lock_v2() for discussion of the lock_level parameter. + * + * Compare *cell_result with cell_prealloc to see if the prealloc was used. + * If cell_prealloc was used then inmate wasn't added to it. + * + * Returns true if the lock is granted. + */ +bool dm_cell_get_v2(struct dm_bio_prison_v2 *prison, + struct dm_cell_key_v2 *key, + unsigned lock_level, + struct bio *inmate, + struct dm_bio_prison_cell_v2 *cell_prealloc, + struct dm_bio_prison_cell_v2 **cell_result); + +/* + * Decrement the shared reference count for the lock. Returns true if + * returning ownership of the cell (ie. you should free it). + */ +bool dm_cell_put_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell); + +/* + * Locks a cell. No associated bio. Exclusive locks get priority. These + * locks constrain whether the io locks are granted according to level. + * + * Shared locks will still be granted if the lock_level is > (not = to) the + * exclusive lock level. + * + * If an _exclusive_ lock is already held then -EBUSY is returned. + * + * Return values: + * < 0 - error + * 0 - locked; no quiescing needed + * 1 - locked; quiescing needed + */ +int dm_cell_lock_v2(struct dm_bio_prison_v2 *prison, + struct dm_cell_key_v2 *key, + unsigned lock_level, + struct dm_bio_prison_cell_v2 *cell_prealloc, + struct dm_bio_prison_cell_v2 **cell_result); + +void dm_cell_quiesce_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell, + struct work_struct *continuation); + +/* + * Promotes an _exclusive_ lock to a higher lock level. + * + * Return values: + * < 0 - error + * 0 - promoted; no quiescing needed + * 1 - promoted; quiescing needed + */ +int dm_cell_lock_promote_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell, + unsigned new_lock_level); + +/* + * Adds any held bios to the bio list. + * + * There may be shared locks still held at this point even if you quiesced + * (ie. different lock levels). + * + * Returns true if returning ownership of the cell (ie. you should free + * it). + */ +bool dm_cell_unlock_v2(struct dm_bio_prison_v2 *prison, + struct dm_bio_prison_cell_v2 *cell, + struct bio_list *bios); + +/*----------------------------------------------------------------*/ + +#endif diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c deleted file mode 100644 index 03af174485d3..000000000000 --- a/drivers/md/dm-bio-prison.c +++ /dev/null @@ -1,424 +0,0 @@ -/* - * Copyright (C) 2012 Red Hat, Inc. - * - * This file is released under the GPL. - */ - -#include "dm.h" -#include "dm-bio-prison.h" - -#include -#include -#include -#include - -/*----------------------------------------------------------------*/ - -#define MIN_CELLS 1024 - -struct dm_bio_prison { - spinlock_t lock; - mempool_t *cell_pool; - struct rb_root cells; -}; - -static struct kmem_cache *_cell_cache; - -/*----------------------------------------------------------------*/ - -/* - * @nr_cells should be the number of cells you want in use _concurrently_. - * Don't confuse it with the number of distinct keys. - */ -struct dm_bio_prison *dm_bio_prison_create(void) -{ - struct dm_bio_prison *prison = kmalloc(sizeof(*prison), GFP_KERNEL); - - if (!prison) - return NULL; - - spin_lock_init(&prison->lock); - - prison->cell_pool = mempool_create_slab_pool(MIN_CELLS, _cell_cache); - if (!prison->cell_pool) { - kfree(prison); - return NULL; - } - - prison->cells = RB_ROOT; - - return prison; -} -EXPORT_SYMBOL_GPL(dm_bio_prison_create); - -void dm_bio_prison_destroy(struct dm_bio_prison *prison) -{ - mempool_destroy(prison->cell_pool); - kfree(prison); -} -EXPORT_SYMBOL_GPL(dm_bio_prison_destroy); - -struct dm_bio_prison_cell *dm_bio_prison_alloc_cell(struct dm_bio_prison *prison, gfp_t gfp) -{ - return mempool_alloc(prison->cell_pool, gfp); -} -EXPORT_SYMBOL_GPL(dm_bio_prison_alloc_cell); - -void dm_bio_prison_free_cell(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell) -{ - mempool_free(cell, prison->cell_pool); -} -EXPORT_SYMBOL_GPL(dm_bio_prison_free_cell); - -static void __setup_new_cell(struct dm_cell_key *key, - struct bio *holder, - struct dm_bio_prison_cell *cell) -{ - memcpy(&cell->key, key, sizeof(cell->key)); - cell->holder = holder; - bio_list_init(&cell->bios); -} - -static int cmp_keys(struct dm_cell_key *lhs, - struct dm_cell_key *rhs) -{ - if (lhs->virtual < rhs->virtual) - return -1; - - if (lhs->virtual > rhs->virtual) - return 1; - - if (lhs->dev < rhs->dev) - return -1; - - if (lhs->dev > rhs->dev) - return 1; - - if (lhs->block_end <= rhs->block_begin) - return -1; - - if (lhs->block_begin >= rhs->block_end) - return 1; - - return 0; -} - -static int __bio_detain(struct dm_bio_prison *prison, - struct dm_cell_key *key, - struct bio *inmate, - struct dm_bio_prison_cell *cell_prealloc, - struct dm_bio_prison_cell **cell_result) -{ - int r; - struct rb_node **new = &prison->cells.rb_node, *parent = NULL; - - while (*new) { - struct dm_bio_prison_cell *cell = - container_of(*new, struct dm_bio_prison_cell, node); - - r = cmp_keys(key, &cell->key); - - parent = *new; - if (r < 0) - new = &((*new)->rb_left); - else if (r > 0) - new = &((*new)->rb_right); - else { - if (inmate) - bio_list_add(&cell->bios, inmate); - *cell_result = cell; - return 1; - } - } - - __setup_new_cell(key, inmate, cell_prealloc); - *cell_result = cell_prealloc; - - rb_link_node(&cell_prealloc->node, parent, new); - rb_insert_color(&cell_prealloc->node, &prison->cells); - - return 0; -} - -static int bio_detain(struct dm_bio_prison *prison, - struct dm_cell_key *key, - struct bio *inmate, - struct dm_bio_prison_cell *cell_prealloc, - struct dm_bio_prison_cell **cell_result) -{ - int r; - unsigned long flags; - - spin_lock_irqsave(&prison->lock, flags); - r = __bio_detain(prison, key, inmate, cell_prealloc, cell_result); - spin_unlock_irqrestore(&prison->lock, flags); - - return r; -} - -int dm_bio_detain(struct dm_bio_prison *prison, - struct dm_cell_key *key, - struct bio *inmate, - struct dm_bio_prison_cell *cell_prealloc, - struct dm_bio_prison_cell **cell_result) -{ - return bio_detain(prison, key, inmate, cell_prealloc, cell_result); -} -EXPORT_SYMBOL_GPL(dm_bio_detain); - -int dm_get_cell(struct dm_bio_prison *prison, - struct dm_cell_key *key, - struct dm_bio_prison_cell *cell_prealloc, - struct dm_bio_prison_cell **cell_result) -{ - return bio_detain(prison, key, NULL, cell_prealloc, cell_result); -} -EXPORT_SYMBOL_GPL(dm_get_cell); - -/* - * @inmates must have been initialised prior to this call - */ -static void __cell_release(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell, - struct bio_list *inmates) -{ - rb_erase(&cell->node, &prison->cells); - - if (inmates) { - if (cell->holder) - bio_list_add(inmates, cell->holder); - bio_list_merge(inmates, &cell->bios); - } -} - -void dm_cell_release(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell, - struct bio_list *bios) -{ - unsigned long flags; - - spin_lock_irqsave(&prison->lock, flags); - __cell_release(prison, cell, bios); - spin_unlock_irqrestore(&prison->lock, flags); -} -EXPORT_SYMBOL_GPL(dm_cell_release); - -/* - * Sometimes we don't want the holder, just the additional bios. - */ -static void __cell_release_no_holder(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell, - struct bio_list *inmates) -{ - rb_erase(&cell->node, &prison->cells); - bio_list_merge(inmates, &cell->bios); -} - -void dm_cell_release_no_holder(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell, - struct bio_list *inmates) -{ - unsigned long flags; - - spin_lock_irqsave(&prison->lock, flags); - __cell_release_no_holder(prison, cell, inmates); - spin_unlock_irqrestore(&prison->lock, flags); -} -EXPORT_SYMBOL_GPL(dm_cell_release_no_holder); - -void dm_cell_error(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell, int error) -{ - struct bio_list bios; - struct bio *bio; - - bio_list_init(&bios); - dm_cell_release(prison, cell, &bios); - - while ((bio = bio_list_pop(&bios))) { - bio->bi_error = error; - bio_endio(bio); - } -} -EXPORT_SYMBOL_GPL(dm_cell_error); - -void dm_cell_visit_release(struct dm_bio_prison *prison, - void (*visit_fn)(void *, struct dm_bio_prison_cell *), - void *context, - struct dm_bio_prison_cell *cell) -{ - unsigned long flags; - - spin_lock_irqsave(&prison->lock, flags); - visit_fn(context, cell); - rb_erase(&cell->node, &prison->cells); - spin_unlock_irqrestore(&prison->lock, flags); -} -EXPORT_SYMBOL_GPL(dm_cell_visit_release); - -static int __promote_or_release(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell) -{ - if (bio_list_empty(&cell->bios)) { - rb_erase(&cell->node, &prison->cells); - return 1; - } - - cell->holder = bio_list_pop(&cell->bios); - return 0; -} - -int dm_cell_promote_or_release(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell) -{ - int r; - unsigned long flags; - - spin_lock_irqsave(&prison->lock, flags); - r = __promote_or_release(prison, cell); - spin_unlock_irqrestore(&prison->lock, flags); - - return r; -} -EXPORT_SYMBOL_GPL(dm_cell_promote_or_release); - -/*----------------------------------------------------------------*/ - -#define DEFERRED_SET_SIZE 64 - -struct dm_deferred_entry { - struct dm_deferred_set *ds; - unsigned count; - struct list_head work_items; -}; - -struct dm_deferred_set { - spinlock_t lock; - unsigned current_entry; - unsigned sweeper; - struct dm_deferred_entry entries[DEFERRED_SET_SIZE]; -}; - -struct dm_deferred_set *dm_deferred_set_create(void) -{ - int i; - struct dm_deferred_set *ds; - - ds = kmalloc(sizeof(*ds), GFP_KERNEL); - if (!ds) - return NULL; - - spin_lock_init(&ds->lock); - ds->current_entry = 0; - ds->sweeper = 0; - for (i = 0; i < DEFERRED_SET_SIZE; i++) { - ds->entries[i].ds = ds; - ds->entries[i].count = 0; - INIT_LIST_HEAD(&ds->entries[i].work_items); - } - - return ds; -} -EXPORT_SYMBOL_GPL(dm_deferred_set_create); - -void dm_deferred_set_destroy(struct dm_deferred_set *ds) -{ - kfree(ds); -} -EXPORT_SYMBOL_GPL(dm_deferred_set_destroy); - -struct dm_deferred_entry *dm_deferred_entry_inc(struct dm_deferred_set *ds) -{ - unsigned long flags; - struct dm_deferred_entry *entry; - - spin_lock_irqsave(&ds->lock, flags); - entry = ds->entries + ds->current_entry; - entry->count++; - spin_unlock_irqrestore(&ds->lock, flags); - - return entry; -} -EXPORT_SYMBOL_GPL(dm_deferred_entry_inc); - -static unsigned ds_next(unsigned index) -{ - return (index + 1) % DEFERRED_SET_SIZE; -} - -static void __sweep(struct dm_deferred_set *ds, struct list_head *head) -{ - while ((ds->sweeper != ds->current_entry) && - !ds->entries[ds->sweeper].count) { - list_splice_init(&ds->entries[ds->sweeper].work_items, head); - ds->sweeper = ds_next(ds->sweeper); - } - - if ((ds->sweeper == ds->current_entry) && !ds->entries[ds->sweeper].count) - list_splice_init(&ds->entries[ds->sweeper].work_items, head); -} - -void dm_deferred_entry_dec(struct dm_deferred_entry *entry, struct list_head *head) -{ - unsigned long flags; - - spin_lock_irqsave(&entry->ds->lock, flags); - BUG_ON(!entry->count); - --entry->count; - __sweep(entry->ds, head); - spin_unlock_irqrestore(&entry->ds->lock, flags); -} -EXPORT_SYMBOL_GPL(dm_deferred_entry_dec); - -/* - * Returns 1 if deferred or 0 if no pending items to delay job. - */ -int dm_deferred_set_add_work(struct dm_deferred_set *ds, struct list_head *work) -{ - int r = 1; - unsigned long flags; - unsigned next_entry; - - spin_lock_irqsave(&ds->lock, flags); - if ((ds->sweeper == ds->current_entry) && - !ds->entries[ds->current_entry].count) - r = 0; - else { - list_add(work, &ds->entries[ds->current_entry].work_items); - next_entry = ds_next(ds->current_entry); - if (!ds->entries[next_entry].count) - ds->current_entry = next_entry; - } - spin_unlock_irqrestore(&ds->lock, flags); - - return r; -} -EXPORT_SYMBOL_GPL(dm_deferred_set_add_work); - -/*----------------------------------------------------------------*/ - -static int __init dm_bio_prison_init(void) -{ - _cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0); - if (!_cell_cache) - return -ENOMEM; - - return 0; -} - -static void __exit dm_bio_prison_exit(void) -{ - kmem_cache_destroy(_cell_cache); - _cell_cache = NULL; -} - -/* - * module hooks - */ -module_init(dm_bio_prison_init); -module_exit(dm_bio_prison_exit); - -MODULE_DESCRIPTION(DM_NAME " bio prison"); -MODULE_AUTHOR("Joe Thornber "); -MODULE_LICENSE("GPL"); diff --git a/drivers/md/dm-bio-prison.h b/drivers/md/dm-bio-prison.h deleted file mode 100644 index 54352f009bfd..000000000000 --- a/drivers/md/dm-bio-prison.h +++ /dev/null @@ -1,138 +0,0 @@ -/* - * Copyright (C) 2011-2012 Red Hat, Inc. - * - * This file is released under the GPL. - */ - -#ifndef DM_BIO_PRISON_H -#define DM_BIO_PRISON_H - -#include "persistent-data/dm-block-manager.h" /* FIXME: for dm_block_t */ -#include "dm-thin-metadata.h" /* FIXME: for dm_thin_id */ - -#include -#include - -/*----------------------------------------------------------------*/ - -/* - * Sometimes we can't deal with a bio straight away. We put them in prison - * where they can't cause any mischief. Bios are put in a cell identified - * by a key, multiple bios can be in the same cell. When the cell is - * subsequently unlocked the bios become available. - */ -struct dm_bio_prison; - -/* - * Keys define a range of blocks within either a virtual or physical - * device. - */ -struct dm_cell_key { - int virtual; - dm_thin_id dev; - dm_block_t block_begin, block_end; -}; - -/* - * Treat this as opaque, only in header so callers can manage allocation - * themselves. - */ -struct dm_bio_prison_cell { - struct list_head user_list; /* for client use */ - struct rb_node node; - - struct dm_cell_key key; - struct bio *holder; - struct bio_list bios; -}; - -struct dm_bio_prison *dm_bio_prison_create(void); -void dm_bio_prison_destroy(struct dm_bio_prison *prison); - -/* - * These two functions just wrap a mempool. This is a transitory step: - * Eventually all bio prison clients should manage their own cell memory. - * - * Like mempool_alloc(), dm_bio_prison_alloc_cell() can only fail if called - * in interrupt context or passed GFP_NOWAIT. - */ -struct dm_bio_prison_cell *dm_bio_prison_alloc_cell(struct dm_bio_prison *prison, - gfp_t gfp); -void dm_bio_prison_free_cell(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell); - -/* - * Creates, or retrieves a cell that overlaps the given key. - * - * Returns 1 if pre-existing cell returned, zero if new cell created using - * @cell_prealloc. - */ -int dm_get_cell(struct dm_bio_prison *prison, - struct dm_cell_key *key, - struct dm_bio_prison_cell *cell_prealloc, - struct dm_bio_prison_cell **cell_result); - -/* - * An atomic op that combines retrieving or creating a cell, and adding a - * bio to it. - * - * Returns 1 if the cell was already held, 0 if @inmate is the new holder. - */ -int dm_bio_detain(struct dm_bio_prison *prison, - struct dm_cell_key *key, - struct bio *inmate, - struct dm_bio_prison_cell *cell_prealloc, - struct dm_bio_prison_cell **cell_result); - -void dm_cell_release(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell, - struct bio_list *bios); -void dm_cell_release_no_holder(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell, - struct bio_list *inmates); -void dm_cell_error(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell, int error); - -/* - * Visits the cell and then releases. Guarantees no new inmates are - * inserted between the visit and release. - */ -void dm_cell_visit_release(struct dm_bio_prison *prison, - void (*visit_fn)(void *, struct dm_bio_prison_cell *), - void *context, struct dm_bio_prison_cell *cell); - -/* - * Rather than always releasing the prisoners in a cell, the client may - * want to promote one of them to be the new holder. There is a race here - * though between releasing an empty cell, and other threads adding new - * inmates. So this function makes the decision with its lock held. - * - * This function can have two outcomes: - * i) An inmate is promoted to be the holder of the cell (return value of 0). - * ii) The cell has no inmate for promotion and is released (return value of 1). - */ -int dm_cell_promote_or_release(struct dm_bio_prison *prison, - struct dm_bio_prison_cell *cell); - -/*----------------------------------------------------------------*/ - -/* - * We use the deferred set to keep track of pending reads to shared blocks. - * We do this to ensure the new mapping caused by a write isn't performed - * until these prior reads have completed. Otherwise the insertion of the - * new mapping could free the old block that the read bios are mapped to. - */ - -struct dm_deferred_set; -struct dm_deferred_entry; - -struct dm_deferred_set *dm_deferred_set_create(void); -void dm_deferred_set_destroy(struct dm_deferred_set *ds); - -struct dm_deferred_entry *dm_deferred_entry_inc(struct dm_deferred_set *ds); -void dm_deferred_entry_dec(struct dm_deferred_entry *entry, struct list_head *head); -int dm_deferred_set_add_work(struct dm_deferred_set *ds, struct list_head *work); - -/*----------------------------------------------------------------*/ - -#endif diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 9c689b34e6e7..2eaa414e1509 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -5,7 +5,7 @@ */ #include "dm.h" -#include "dm-bio-prison.h" +#include "dm-bio-prison-v1.h" #include "dm-bio-record.h" #include "dm-cache-metadata.h" diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 2b266a2b5035..9b3e2fcbfb1b 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -5,7 +5,7 @@ */ #include "dm-thin-metadata.h" -#include "dm-bio-prison.h" +#include "dm-bio-prison-v1.h" #include "dm.h" #include