* [PATCH 1/3] dm bio prison: factor bio prison code out to standalone library
@ 2012-09-25 22:35 Mike Snitzer
2012-09-25 22:35 ` [PATCH 2/3] dm thin: remove old bio prison code that now lives in dm-bio-prison.c Mike Snitzer
2012-09-25 22:35 ` [PATCH 3/3] dm bio prison: add "dm_" prefix to bio prison and deferred set interfaces Mike Snitzer
0 siblings, 2 replies; 3+ messages in thread
From: Mike Snitzer @ 2012-09-25 22:35 UTC (permalink / raw)
To: dm-devel
The bio prison code will be useful to other future DM targets. No
functional change, code was factored out to facilitate code re-use.
Old bio-prison code in dm-thin.c was commented out to avoid all the code
removal noise in favor of focusing on the non-removal changes needed to
separate the code out of dm-thin.c
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
---
drivers/md/Kconfig | 7 +
drivers/md/Makefile | 1 +
drivers/md/dm-bio-prison.c | 429 ++++++++++++++++++++++++++++++++++++++++++++
drivers/md/dm-bio-prison.h | 76 ++++++++
drivers/md/dm-thin.c | 40 +++--
5 files changed, 537 insertions(+), 16 deletions(-)
create mode 100644 drivers/md/dm-bio-prison.c
create mode 100644 drivers/md/dm-bio-prison.h
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index d949b78..78c70a8 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -216,6 +216,12 @@ config DM_BUFIO
as a cache, holding recently-read blocks in memory and performing
delayed writes.
+config DM_BIO_PRISON
+ tristate
+ depends on BLK_DEV_DM && EXPERIMENTAL
+ ---help---
+ Some bio locking schemes used by device-mapper targets.
+
source "drivers/md/persistent-data/Kconfig"
config DM_CRYPT
@@ -247,6 +253,7 @@ config DM_THIN_PROVISIONING
tristate "Thin provisioning target (EXPERIMENTAL)"
depends on BLK_DEV_DM && EXPERIMENTAL
select DM_PERSISTENT_DATA
+ select DM_BIO_PRISON
---help---
Provides thin provisioning and snapshots that share a data store.
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 8b2e0df..94dce8b 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_MD_FAULTY) += faulty.o
obj-$(CONFIG_BLK_DEV_MD) += md-mod.o
obj-$(CONFIG_BLK_DEV_DM) += dm-mod.o
obj-$(CONFIG_DM_BUFIO) += dm-bufio.o
+obj-$(CONFIG_DM_BIO_PRISON) += dm-bio-prison.o
obj-$(CONFIG_DM_CRYPT) += dm-crypt.o
obj-$(CONFIG_DM_DELAY) += dm-delay.o
obj-$(CONFIG_DM_FLAKEY) += dm-flakey.o
diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c
new file mode 100644
index 0000000..fdf9c19
--- /dev/null
+++ b/drivers/md/dm-bio-prison.c
@@ -0,0 +1,429 @@
+/*
+ * Copyright (C) 2012 Red Hat UK.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm.h"
+#include "dm-bio-prison.h"
+
+#include <linux/spinlock.h>
+#include <linux/mempool.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+/*----------------------------------------------------------------*/
+
+struct dm_bio_prison_cell {
+ struct hlist_node list;
+ struct bio_prison *prison;
+ struct cell_key key;
+ struct bio *holder;
+ struct bio_list bios;
+};
+
+struct bio_prison {
+ spinlock_t lock;
+ mempool_t *cell_pool;
+
+ unsigned nr_buckets;
+ unsigned hash_mask;
+ struct hlist_head *cells;
+};
+
+/*----------------------------------------------------------------*/
+
+static uint32_t calc_nr_buckets(unsigned nr_cells)
+{
+ uint32_t n = 128;
+
+ nr_cells /= 4;
+ nr_cells = min(nr_cells, 8192u);
+
+ while (n < nr_cells)
+ n <<= 1;
+
+ return n;
+}
+
+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 bio_prison *prison_create(unsigned nr_cells)
+{
+ unsigned i;
+ uint32_t nr_buckets = calc_nr_buckets(nr_cells);
+ size_t len = sizeof(struct bio_prison) +
+ (sizeof(struct hlist_head) * nr_buckets);
+ struct bio_prison *prison = kmalloc(len, GFP_KERNEL);
+
+ if (!prison)
+ return NULL;
+
+ spin_lock_init(&prison->lock);
+ prison->cell_pool = mempool_create_slab_pool(nr_cells, _cell_cache);
+ if (!prison->cell_pool) {
+ kfree(prison);
+ return NULL;
+ }
+
+ prison->nr_buckets = nr_buckets;
+ prison->hash_mask = nr_buckets - 1;
+ prison->cells = (struct hlist_head *) (prison + 1);
+ for (i = 0; i < nr_buckets; i++)
+ INIT_HLIST_HEAD(prison->cells + i);
+
+ return prison;
+}
+EXPORT_SYMBOL_GPL(prison_create);
+
+void prison_destroy(struct bio_prison *prison)
+{
+ mempool_destroy(prison->cell_pool);
+ kfree(prison);
+}
+EXPORT_SYMBOL_GPL(prison_destroy);
+
+static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key)
+{
+ const unsigned long BIG_PRIME = 4294967291UL;
+ uint64_t hash = key->block * BIG_PRIME;
+
+ return (uint32_t) (hash & prison->hash_mask);
+}
+
+static int keys_equal(struct cell_key *lhs, struct cell_key *rhs)
+{
+ return (lhs->virtual == rhs->virtual) &&
+ (lhs->dev == rhs->dev) &&
+ (lhs->block == rhs->block);
+}
+
+static struct dm_bio_prison_cell *__search_bucket(struct hlist_head *bucket,
+ struct cell_key *key)
+{
+ struct dm_bio_prison_cell *cell;
+ struct hlist_node *tmp;
+
+ hlist_for_each_entry(cell, tmp, bucket, list)
+ if (keys_equal(&cell->key, key))
+ return cell;
+
+ return NULL;
+}
+
+int bio_detain(struct bio_prison *prison, struct cell_key *key,
+ struct bio *inmate, struct dm_bio_prison_cell **ref)
+{
+ int r = 1;
+ unsigned long flags;
+ uint32_t hash = hash_key(prison, key);
+ struct dm_bio_prison_cell *cell, *cell2;
+
+ BUG_ON(hash > prison->nr_buckets);
+
+ spin_lock_irqsave(&prison->lock, flags);
+
+ cell = __search_bucket(prison->cells + hash, key);
+ if (cell) {
+ bio_list_add(&cell->bios, inmate);
+ goto out;
+ }
+
+ /*
+ * Allocate a new cell
+ */
+ spin_unlock_irqrestore(&prison->lock, flags);
+ cell2 = mempool_alloc(prison->cell_pool, GFP_NOIO);
+ spin_lock_irqsave(&prison->lock, flags);
+
+ /*
+ * We've been unlocked, so we have to double check that
+ * nobody else has inserted this cell in the meantime.
+ */
+ cell = __search_bucket(prison->cells + hash, key);
+ if (cell) {
+ mempool_free(cell2, prison->cell_pool);
+ bio_list_add(&cell->bios, inmate);
+ goto out;
+ }
+
+ /*
+ * Use new cell.
+ */
+ cell = cell2;
+
+ cell->prison = prison;
+ memcpy(&cell->key, key, sizeof(cell->key));
+ cell->holder = inmate;
+ bio_list_init(&cell->bios);
+ hlist_add_head(&cell->list, prison->cells + hash);
+
+ r = 0;
+
+out:
+ spin_unlock_irqrestore(&prison->lock, flags);
+
+ *ref = cell;
+ return r;
+}
+EXPORT_SYMBOL_GPL(bio_detain);
+
+int bio_detain_if_occupied(struct bio_prison *prison, struct cell_key *key,
+ struct bio *inmate)
+{
+ int r = 0;
+ unsigned long flags;
+ uint32_t hash = hash_key(prison, key);
+ struct dm_bio_prison_cell *cell;
+
+ BUG_ON(hash > prison->nr_buckets);
+
+ spin_lock_irqsave(&prison->lock, flags);
+
+ cell = __search_bucket(prison->cells + hash, key);
+ if (cell) {
+ bio_list_add(&cell->bios, inmate);
+ r = 1;
+ }
+
+ spin_unlock_irqrestore(&prison->lock, flags);
+ return r;
+}
+EXPORT_SYMBOL_GPL(bio_detain_if_occupied);
+
+/*
+ * @inmates must have been initialised prior to this call
+ */
+static void __cell_release(struct dm_bio_prison_cell *cell, struct bio_list *inmates)
+{
+ struct bio_prison *prison = cell->prison;
+
+ hlist_del(&cell->list);
+
+ if (inmates) {
+ bio_list_add(inmates, cell->holder);
+ bio_list_merge(inmates, &cell->bios);
+ }
+
+ mempool_free(cell, prison->cell_pool);
+}
+
+void cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios)
+{
+ unsigned long flags;
+ struct bio_prison *prison = cell->prison;
+
+ spin_lock_irqsave(&prison->lock, flags);
+ __cell_release(cell, bios);
+ spin_unlock_irqrestore(&prison->lock, flags);
+}
+EXPORT_SYMBOL_GPL(cell_release);
+
+/*
+ * There are a couple of places where we put a bio into a cell briefly
+ * before taking it out again. In these situations we know that no other
+ * bio may be in the cell. This function releases the cell, and also does
+ * a sanity check.
+ */
+static void __cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
+{
+ BUG_ON(cell->holder != bio);
+ BUG_ON(!bio_list_empty(&cell->bios));
+
+ __cell_release(cell, NULL);
+}
+
+void cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
+{
+ unsigned long flags;
+ struct bio_prison *prison = cell->prison;
+
+ spin_lock_irqsave(&prison->lock, flags);
+ __cell_release_singleton(cell, bio);
+ spin_unlock_irqrestore(&prison->lock, flags);
+}
+EXPORT_SYMBOL_GPL(cell_release_singleton);
+
+/*
+ * Sometimes we don't want the holder, just the additional bios.
+ */
+static void __cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates)
+{
+ struct bio_prison *prison = cell->prison;
+
+ hlist_del(&cell->list);
+ bio_list_merge(inmates, &cell->bios);
+
+ mempool_free(cell, prison->cell_pool);
+}
+
+void cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates)
+{
+ unsigned long flags;
+ struct bio_prison *prison = cell->prison;
+
+ spin_lock_irqsave(&prison->lock, flags);
+ __cell_release_no_holder(cell, inmates);
+ spin_unlock_irqrestore(&prison->lock, flags);
+}
+EXPORT_SYMBOL_GPL(cell_release_no_holder);
+
+void cell_error(struct dm_bio_prison_cell *cell)
+{
+ struct bio_prison *prison = cell->prison;
+ struct bio_list bios;
+ struct bio *bio;
+ unsigned long flags;
+
+ bio_list_init(&bios);
+
+ spin_lock_irqsave(&prison->lock, flags);
+ __cell_release(cell, &bios);
+ spin_unlock_irqrestore(&prison->lock, flags);
+
+ while ((bio = bio_list_pop(&bios)))
+ bio_io_error(bio);
+}
+EXPORT_SYMBOL_GPL(cell_error);
+
+/*----------------------------------------------------------------*/
+
+#define DEFERRED_SET_SIZE 64
+
+struct deferred_entry {
+ struct deferred_set *ds;
+ unsigned count;
+ struct list_head work_items;
+};
+
+struct deferred_set {
+ spinlock_t lock;
+ unsigned current_entry;
+ unsigned sweeper;
+ struct deferred_entry entries[DEFERRED_SET_SIZE];
+};
+
+struct deferred_set *ds_create(void)
+{
+ int i;
+ struct deferred_set *ds;
+
+ ds = kmalloc(sizeof(*ds), GFP_KERNEL);
+
+ 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(ds_create);
+
+void ds_destroy(struct deferred_set *ds)
+{
+ kfree(ds);
+}
+EXPORT_SYMBOL_GPL(ds_destroy);
+
+struct deferred_entry *ds_inc(struct deferred_set *ds)
+{
+ unsigned long flags;
+ struct 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(ds_inc);
+
+static unsigned ds_next(unsigned index)
+{
+ return (index + 1) % DEFERRED_SET_SIZE;
+}
+
+static void __sweep(struct 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 ds_dec(struct 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(ds_dec);
+
+/*
+ * Returns 1 if deferred or 0 if no pending items to delay job.
+ */
+int ds_add_work(struct 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(ds_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 <dm-devel@redhat.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/md/dm-bio-prison.h b/drivers/md/dm-bio-prison.h
new file mode 100644
index 0000000..0d9d270
--- /dev/null
+++ b/drivers/md/dm-bio-prison.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2012 Red Hat UK. All rights reserved.
+ *
+ * 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 <linux/list.h>
+#include <linux/bio.h>
+
+/*----------------------------------------------------------------*/
+
+/* FIXME: prefix everything */
+
+/*
+ * 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 bio_prison;
+struct dm_bio_prison_cell;
+
+/* FIXME: this needs to be more abstract */
+struct cell_key {
+ int virtual;
+ dm_thin_id dev;
+ dm_block_t block;
+};
+
+struct bio_prison *prison_create(unsigned nr_cells);
+void prison_destroy(struct bio_prison *prison);
+
+/*
+ * This may block if a new cell needs allocating. You must ensure that
+ * cells will be unlocked even if the calling thread is blocked.
+ *
+ * Returns 1 if the cell was already held, 0 if @inmate is the new holder.
+ */
+int bio_detain(struct bio_prison *prison, struct cell_key *key,
+ struct bio *inmate, struct dm_bio_prison_cell **ref);
+int bio_detain_if_occupied(struct bio_prison *prison, struct cell_key *key,
+ struct bio *inmate);
+
+void cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios);
+void cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio); // FIXME: bio arg not needed
+void cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates);
+void cell_error(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 deferred_set;
+struct deferred_entry;
+
+struct deferred_set *ds_create(void);
+void ds_destroy(struct deferred_set *ds);
+
+struct deferred_entry *ds_inc(struct deferred_set *ds);
+void ds_dec(struct deferred_entry *entry, struct list_head *head);
+int ds_add_work(struct deferred_set *ds, struct list_head *work);
+
+/*----------------------------------------------------------------*/
+
+#endif
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 8e73f43..39f4d40 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -5,6 +5,7 @@
*/
#include "dm-thin-metadata.h"
+#include "dm-bio-prison.h"
#include "dm.h"
#include <linux/device-mapper.h>
@@ -21,7 +22,6 @@
* Tunable constants
*/
#define ENDIO_HOOK_POOL_SIZE 1024
-#define DEFERRED_SET_SIZE 64
#define MAPPING_POOL_SIZE 1024
#define PRISON_CELLS 1024
#define COMMIT_PERIOD HZ
@@ -98,6 +98,7 @@
/*----------------------------------------------------------------*/
+#if 0
/*
* 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
@@ -467,6 +468,8 @@ static int ds_add_work(struct deferred_set *ds, struct list_head *work)
return r;
}
+#endif
+
/*----------------------------------------------------------------*/
/*
@@ -552,8 +555,8 @@ struct pool {
struct bio_list retry_on_resume_list;
- struct deferred_set shared_read_ds;
- struct deferred_set all_io_ds;
+ struct deferred_set *shared_read_ds;
+ struct deferred_set *all_io_ds;
struct dm_thin_new_mapping *next_mapping;
mempool_t *mapping_pool;
@@ -1067,7 +1070,7 @@ static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
m->err = 0;
m->bio = NULL;
- if (!ds_add_work(&pool->shared_read_ds, &m->list))
+ if (!ds_add_work(pool->shared_read_ds, &m->list))
m->quiesced = 1;
/*
@@ -1326,7 +1329,7 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
m->err = 0;
m->bio = bio;
- if (!ds_add_work(&pool->all_io_ds, &m->list)) {
+ if (!ds_add_work(pool->all_io_ds, &m->list)) {
spin_lock_irqsave(&pool->lock, flags);
list_add(&m->list, &pool->prepared_discards);
spin_unlock_irqrestore(&pool->lock, flags);
@@ -1410,7 +1413,7 @@ static void process_shared_bio(struct thin_c *tc, struct bio *bio,
else {
struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;
- h->shared_read_entry = ds_inc(&pool->shared_read_ds);
+ h->shared_read_entry = ds_inc(pool->shared_read_ds);
cell_release_singleton(cell, bio);
remap_and_issue(tc, bio, lookup_result->block);
@@ -1718,7 +1721,7 @@ static struct dm_thin_endio_hook *thin_hook_bio(struct thin_c *tc, struct bio *b
h->tc = tc;
h->shared_read_entry = NULL;
- h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : ds_inc(&pool->all_io_ds);
+ h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : ds_inc(pool->all_io_ds);
h->overwrite_mapping = NULL;
return h;
@@ -1938,6 +1941,8 @@ static void __pool_destroy(struct pool *pool)
mempool_free(pool->next_mapping, pool->mapping_pool);
mempool_destroy(pool->mapping_pool);
mempool_destroy(pool->endio_hook_pool);
+ ds_destroy(pool->shared_read_ds);
+ ds_destroy(pool->all_io_ds);
kfree(pool);
}
@@ -2012,8 +2017,14 @@ static struct pool *pool_create(struct mapped_device *pool_md,
pool->low_water_triggered = 0;
pool->no_free_space = 0;
bio_list_init(&pool->retry_on_resume_list);
- ds_init(&pool->shared_read_ds);
- ds_init(&pool->all_io_ds);
+
+ pool->shared_read_ds = ds_create();
+ if (!pool->shared_read_ds)
+ goto bad_shared_ds;
+
+ pool->all_io_ds = ds_create();
+ if (!pool->all_io_ds)
+ goto bad_all_io_ds;
pool->next_mapping = NULL;
pool->mapping_pool = mempool_create_slab_pool(MAPPING_POOL_SIZE,
@@ -2042,6 +2053,10 @@ static struct pool *pool_create(struct mapped_device *pool_md,
bad_endio_hook_pool:
mempool_destroy(pool->mapping_pool);
bad_mapping_pool:
+ ds_destroy(pool->all_io_ds);
+bad_all_io_ds:
+ ds_destroy(pool->shared_read_ds);
+bad_shared_ds:
destroy_workqueue(pool->wq);
bad_wq:
dm_kcopyd_client_destroy(pool->copier);
@@ -3129,10 +3144,6 @@ static int __init dm_thin_init(void)
r = -ENOMEM;
- _cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0);
- if (!_cell_cache)
- goto bad_cell_cache;
-
_new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
if (!_new_mapping_cache)
goto bad_new_mapping_cache;
@@ -3146,8 +3157,6 @@ static int __init dm_thin_init(void)
bad_endio_hook_cache:
kmem_cache_destroy(_new_mapping_cache);
bad_new_mapping_cache:
- kmem_cache_destroy(_cell_cache);
-bad_cell_cache:
dm_unregister_target(&pool_target);
bad_pool_target:
dm_unregister_target(&thin_target);
@@ -3160,7 +3169,6 @@ static void dm_thin_exit(void)
dm_unregister_target(&thin_target);
dm_unregister_target(&pool_target);
- kmem_cache_destroy(_cell_cache);
kmem_cache_destroy(_new_mapping_cache);
kmem_cache_destroy(_endio_hook_cache);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 2/3] dm thin: remove old bio prison code that now lives in dm-bio-prison.c
2012-09-25 22:35 [PATCH 1/3] dm bio prison: factor bio prison code out to standalone library Mike Snitzer
@ 2012-09-25 22:35 ` Mike Snitzer
2012-09-25 22:35 ` [PATCH 3/3] dm bio prison: add "dm_" prefix to bio prison and deferred set interfaces Mike Snitzer
1 sibling, 0 replies; 3+ messages in thread
From: Mike Snitzer @ 2012-09-25 22:35 UTC (permalink / raw)
To: dm-devel
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-thin.c | 374 --------------------------------------------------
1 files changed, 0 insertions(+), 374 deletions(-)
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 39f4d40..1d4831f 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -98,380 +98,6 @@
/*----------------------------------------------------------------*/
-#if 0
-/*
- * 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 bio_prison;
-
-struct cell_key {
- int virtual;
- dm_thin_id dev;
- dm_block_t block;
-};
-
-struct dm_bio_prison_cell {
- struct hlist_node list;
- struct bio_prison *prison;
- struct cell_key key;
- struct bio *holder;
- struct bio_list bios;
-};
-
-struct bio_prison {
- spinlock_t lock;
- mempool_t *cell_pool;
-
- unsigned nr_buckets;
- unsigned hash_mask;
- struct hlist_head *cells;
-};
-
-static uint32_t calc_nr_buckets(unsigned nr_cells)
-{
- uint32_t n = 128;
-
- nr_cells /= 4;
- nr_cells = min(nr_cells, 8192u);
-
- while (n < nr_cells)
- n <<= 1;
-
- return n;
-}
-
-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.
- */
-static struct bio_prison *prison_create(unsigned nr_cells)
-{
- unsigned i;
- uint32_t nr_buckets = calc_nr_buckets(nr_cells);
- size_t len = sizeof(struct bio_prison) +
- (sizeof(struct hlist_head) * nr_buckets);
- struct bio_prison *prison = kmalloc(len, GFP_KERNEL);
-
- if (!prison)
- return NULL;
-
- spin_lock_init(&prison->lock);
- prison->cell_pool = mempool_create_slab_pool(nr_cells, _cell_cache);
- if (!prison->cell_pool) {
- kfree(prison);
- return NULL;
- }
-
- prison->nr_buckets = nr_buckets;
- prison->hash_mask = nr_buckets - 1;
- prison->cells = (struct hlist_head *) (prison + 1);
- for (i = 0; i < nr_buckets; i++)
- INIT_HLIST_HEAD(prison->cells + i);
-
- return prison;
-}
-
-static void prison_destroy(struct bio_prison *prison)
-{
- mempool_destroy(prison->cell_pool);
- kfree(prison);
-}
-
-static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key)
-{
- const unsigned long BIG_PRIME = 4294967291UL;
- uint64_t hash = key->block * BIG_PRIME;
-
- return (uint32_t) (hash & prison->hash_mask);
-}
-
-static int keys_equal(struct cell_key *lhs, struct cell_key *rhs)
-{
- return (lhs->virtual == rhs->virtual) &&
- (lhs->dev == rhs->dev) &&
- (lhs->block == rhs->block);
-}
-
-static struct dm_bio_prison_cell *__search_bucket(struct hlist_head *bucket,
- struct cell_key *key)
-{
- struct dm_bio_prison_cell *cell;
- struct hlist_node *tmp;
-
- hlist_for_each_entry(cell, tmp, bucket, list)
- if (keys_equal(&cell->key, key))
- return cell;
-
- return NULL;
-}
-
-/*
- * This may block if a new cell needs allocating. You must ensure that
- * cells will be unlocked even if the calling thread is blocked.
- *
- * Returns 1 if the cell was already held, 0 if @inmate is the new holder.
- */
-static int bio_detain(struct bio_prison *prison, struct cell_key *key,
- struct bio *inmate, struct dm_bio_prison_cell **ref)
-{
- int r = 1;
- unsigned long flags;
- uint32_t hash = hash_key(prison, key);
- struct dm_bio_prison_cell *cell, *cell2;
-
- BUG_ON(hash > prison->nr_buckets);
-
- spin_lock_irqsave(&prison->lock, flags);
-
- cell = __search_bucket(prison->cells + hash, key);
- if (cell) {
- bio_list_add(&cell->bios, inmate);
- goto out;
- }
-
- /*
- * Allocate a new cell
- */
- spin_unlock_irqrestore(&prison->lock, flags);
- cell2 = mempool_alloc(prison->cell_pool, GFP_NOIO);
- spin_lock_irqsave(&prison->lock, flags);
-
- /*
- * We've been unlocked, so we have to double check that
- * nobody else has inserted this cell in the meantime.
- */
- cell = __search_bucket(prison->cells + hash, key);
- if (cell) {
- mempool_free(cell2, prison->cell_pool);
- bio_list_add(&cell->bios, inmate);
- goto out;
- }
-
- /*
- * Use new cell.
- */
- cell = cell2;
-
- cell->prison = prison;
- memcpy(&cell->key, key, sizeof(cell->key));
- cell->holder = inmate;
- bio_list_init(&cell->bios);
- hlist_add_head(&cell->list, prison->cells + hash);
-
- r = 0;
-
-out:
- spin_unlock_irqrestore(&prison->lock, flags);
-
- *ref = cell;
-
- return r;
-}
-
-/*
- * @inmates must have been initialised prior to this call
- */
-static void __cell_release(struct dm_bio_prison_cell *cell, struct bio_list *inmates)
-{
- struct bio_prison *prison = cell->prison;
-
- hlist_del(&cell->list);
-
- if (inmates) {
- bio_list_add(inmates, cell->holder);
- bio_list_merge(inmates, &cell->bios);
- }
-
- mempool_free(cell, prison->cell_pool);
-}
-
-static void cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios)
-{
- unsigned long flags;
- struct bio_prison *prison = cell->prison;
-
- spin_lock_irqsave(&prison->lock, flags);
- __cell_release(cell, bios);
- spin_unlock_irqrestore(&prison->lock, flags);
-}
-
-/*
- * There are a couple of places where we put a bio into a cell briefly
- * before taking it out again. In these situations we know that no other
- * bio may be in the cell. This function releases the cell, and also does
- * a sanity check.
- */
-static void __cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
-{
- BUG_ON(cell->holder != bio);
- BUG_ON(!bio_list_empty(&cell->bios));
-
- __cell_release(cell, NULL);
-}
-
-static void cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
-{
- unsigned long flags;
- struct bio_prison *prison = cell->prison;
-
- spin_lock_irqsave(&prison->lock, flags);
- __cell_release_singleton(cell, bio);
- spin_unlock_irqrestore(&prison->lock, flags);
-}
-
-/*
- * Sometimes we don't want the holder, just the additional bios.
- */
-static void __cell_release_no_holder(struct dm_bio_prison_cell *cell,
- struct bio_list *inmates)
-{
- struct bio_prison *prison = cell->prison;
-
- hlist_del(&cell->list);
- bio_list_merge(inmates, &cell->bios);
-
- mempool_free(cell, prison->cell_pool);
-}
-
-static void cell_release_no_holder(struct dm_bio_prison_cell *cell,
- struct bio_list *inmates)
-{
- unsigned long flags;
- struct bio_prison *prison = cell->prison;
-
- spin_lock_irqsave(&prison->lock, flags);
- __cell_release_no_holder(cell, inmates);
- spin_unlock_irqrestore(&prison->lock, flags);
-}
-
-static void cell_error(struct dm_bio_prison_cell *cell)
-{
- struct bio_prison *prison = cell->prison;
- struct bio_list bios;
- struct bio *bio;
- unsigned long flags;
-
- bio_list_init(&bios);
-
- spin_lock_irqsave(&prison->lock, flags);
- __cell_release(cell, &bios);
- spin_unlock_irqrestore(&prison->lock, flags);
-
- while ((bio = bio_list_pop(&bios)))
- bio_io_error(bio);
-}
-
-/*----------------------------------------------------------------*/
-
-/*
- * 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 deferred_set;
-struct deferred_entry {
- struct deferred_set *ds;
- unsigned count;
- struct list_head work_items;
-};
-
-struct deferred_set {
- spinlock_t lock;
- unsigned current_entry;
- unsigned sweeper;
- struct deferred_entry entries[DEFERRED_SET_SIZE];
-};
-
-static void ds_init(struct deferred_set *ds)
-{
- int i;
-
- 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);
- }
-}
-
-static struct deferred_entry *ds_inc(struct deferred_set *ds)
-{
- unsigned long flags;
- struct 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;
-}
-
-static unsigned ds_next(unsigned index)
-{
- return (index + 1) % DEFERRED_SET_SIZE;
-}
-
-static void __sweep(struct 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);
-}
-
-static void ds_dec(struct 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);
-}
-
-/*
- * Returns 1 if deferred or 0 if no pending items to delay job.
- */
-static int ds_add_work(struct 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;
-}
-
-#endif
-
-/*----------------------------------------------------------------*/
-
/*
* Key building.
*/
--
1.7.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 3/3] dm bio prison: add "dm_" prefix to bio prison and deferred set interfaces
2012-09-25 22:35 [PATCH 1/3] dm bio prison: factor bio prison code out to standalone library Mike Snitzer
2012-09-25 22:35 ` [PATCH 2/3] dm thin: remove old bio prison code that now lives in dm-bio-prison.c Mike Snitzer
@ 2012-09-25 22:35 ` Mike Snitzer
1 sibling, 0 replies; 3+ messages in thread
From: Mike Snitzer @ 2012-09-25 22:35 UTC (permalink / raw)
To: dm-devel
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-bio-prison.c | 94 ++++++++++++++++++++--------------------
drivers/md/dm-bio-prison.h | 40 ++++++++---------
drivers/md/dm-thin.c | 102 ++++++++++++++++++++++----------------------
3 files changed, 117 insertions(+), 119 deletions(-)
diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c
index fdf9c19..b3b7d60 100644
--- a/drivers/md/dm-bio-prison.c
+++ b/drivers/md/dm-bio-prison.c
@@ -16,13 +16,13 @@
struct dm_bio_prison_cell {
struct hlist_node list;
- struct bio_prison *prison;
- struct cell_key key;
+ struct dm_bio_prison *prison;
+ struct dm_cell_key key;
struct bio *holder;
struct bio_list bios;
};
-struct bio_prison {
+struct dm_bio_prison {
spinlock_t lock;
mempool_t *cell_pool;
@@ -52,13 +52,13 @@ 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 bio_prison *prison_create(unsigned nr_cells)
+struct dm_bio_prison *dm_bio_prison_create(unsigned nr_cells)
{
unsigned i;
uint32_t nr_buckets = calc_nr_buckets(nr_cells);
- size_t len = sizeof(struct bio_prison) +
+ size_t len = sizeof(struct dm_bio_prison) +
(sizeof(struct hlist_head) * nr_buckets);
- struct bio_prison *prison = kmalloc(len, GFP_KERNEL);
+ struct dm_bio_prison *prison = kmalloc(len, GFP_KERNEL);
if (!prison)
return NULL;
@@ -78,16 +78,16 @@ struct bio_prison *prison_create(unsigned nr_cells)
return prison;
}
-EXPORT_SYMBOL_GPL(prison_create);
+EXPORT_SYMBOL_GPL(dm_bio_prison_create);
-void prison_destroy(struct bio_prison *prison)
+void dm_bio_prison_destroy(struct dm_bio_prison *prison)
{
mempool_destroy(prison->cell_pool);
kfree(prison);
}
-EXPORT_SYMBOL_GPL(prison_destroy);
+EXPORT_SYMBOL_GPL(dm_bio_prison_destroy);
-static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key)
+static uint32_t hash_key(struct dm_bio_prison *prison, struct dm_cell_key *key)
{
const unsigned long BIG_PRIME = 4294967291UL;
uint64_t hash = key->block * BIG_PRIME;
@@ -95,7 +95,7 @@ static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key)
return (uint32_t) (hash & prison->hash_mask);
}
-static int keys_equal(struct cell_key *lhs, struct cell_key *rhs)
+static int keys_equal(struct dm_cell_key *lhs, struct dm_cell_key *rhs)
{
return (lhs->virtual == rhs->virtual) &&
(lhs->dev == rhs->dev) &&
@@ -103,7 +103,7 @@ static int keys_equal(struct cell_key *lhs, struct cell_key *rhs)
}
static struct dm_bio_prison_cell *__search_bucket(struct hlist_head *bucket,
- struct cell_key *key)
+ struct dm_cell_key *key)
{
struct dm_bio_prison_cell *cell;
struct hlist_node *tmp;
@@ -115,8 +115,8 @@ static struct dm_bio_prison_cell *__search_bucket(struct hlist_head *bucket,
return NULL;
}
-int bio_detain(struct bio_prison *prison, struct cell_key *key,
- struct bio *inmate, struct dm_bio_prison_cell **ref)
+int dm_bio_detain(struct dm_bio_prison *prison, struct dm_cell_key *key,
+ struct bio *inmate, struct dm_bio_prison_cell **ref)
{
int r = 1;
unsigned long flags;
@@ -170,9 +170,9 @@ out:
*ref = cell;
return r;
}
-EXPORT_SYMBOL_GPL(bio_detain);
+EXPORT_SYMBOL_GPL(dm_bio_detain);
-int bio_detain_if_occupied(struct bio_prison *prison, struct cell_key *key,
+int bio_detain_if_occupied(struct dm_bio_prison *prison, struct dm_cell_key *key,
struct bio *inmate)
{
int r = 0;
@@ -200,7 +200,7 @@ EXPORT_SYMBOL_GPL(bio_detain_if_occupied);
*/
static void __cell_release(struct dm_bio_prison_cell *cell, struct bio_list *inmates)
{
- struct bio_prison *prison = cell->prison;
+ struct dm_bio_prison *prison = cell->prison;
hlist_del(&cell->list);
@@ -212,16 +212,16 @@ static void __cell_release(struct dm_bio_prison_cell *cell, struct bio_list *inm
mempool_free(cell, prison->cell_pool);
}
-void cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios)
+void dm_cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios)
{
unsigned long flags;
- struct bio_prison *prison = cell->prison;
+ struct dm_bio_prison *prison = cell->prison;
spin_lock_irqsave(&prison->lock, flags);
__cell_release(cell, bios);
spin_unlock_irqrestore(&prison->lock, flags);
}
-EXPORT_SYMBOL_GPL(cell_release);
+EXPORT_SYMBOL_GPL(dm_cell_release);
/*
* There are a couple of places where we put a bio into a cell briefly
@@ -237,23 +237,23 @@ static void __cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio
__cell_release(cell, NULL);
}
-void cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
+void dm_cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
{
unsigned long flags;
- struct bio_prison *prison = cell->prison;
+ struct dm_bio_prison *prison = cell->prison;
spin_lock_irqsave(&prison->lock, flags);
__cell_release_singleton(cell, bio);
spin_unlock_irqrestore(&prison->lock, flags);
}
-EXPORT_SYMBOL_GPL(cell_release_singleton);
+EXPORT_SYMBOL_GPL(dm_cell_release_singleton);
/*
* Sometimes we don't want the holder, just the additional bios.
*/
static void __cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates)
{
- struct bio_prison *prison = cell->prison;
+ struct dm_bio_prison *prison = cell->prison;
hlist_del(&cell->list);
bio_list_merge(inmates, &cell->bios);
@@ -261,20 +261,20 @@ static void __cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio
mempool_free(cell, prison->cell_pool);
}
-void cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates)
+void dm_cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates)
{
unsigned long flags;
- struct bio_prison *prison = cell->prison;
+ struct dm_bio_prison *prison = cell->prison;
spin_lock_irqsave(&prison->lock, flags);
__cell_release_no_holder(cell, inmates);
spin_unlock_irqrestore(&prison->lock, flags);
}
-EXPORT_SYMBOL_GPL(cell_release_no_holder);
+EXPORT_SYMBOL_GPL(dm_cell_release_no_holder);
-void cell_error(struct dm_bio_prison_cell *cell)
+void dm_cell_error(struct dm_bio_prison_cell *cell)
{
- struct bio_prison *prison = cell->prison;
+ struct dm_bio_prison *prison = cell->prison;
struct bio_list bios;
struct bio *bio;
unsigned long flags;
@@ -288,29 +288,29 @@ void cell_error(struct dm_bio_prison_cell *cell)
while ((bio = bio_list_pop(&bios)))
bio_io_error(bio);
}
-EXPORT_SYMBOL_GPL(cell_error);
+EXPORT_SYMBOL_GPL(dm_cell_error);
/*----------------------------------------------------------------*/
#define DEFERRED_SET_SIZE 64
-struct deferred_entry {
- struct deferred_set *ds;
+struct dm_deferred_entry {
+ struct dm_deferred_set *ds;
unsigned count;
struct list_head work_items;
};
-struct deferred_set {
+struct dm_deferred_set {
spinlock_t lock;
unsigned current_entry;
unsigned sweeper;
- struct deferred_entry entries[DEFERRED_SET_SIZE];
+ struct dm_deferred_entry entries[DEFERRED_SET_SIZE];
};
-struct deferred_set *ds_create(void)
+struct dm_deferred_set *dm_ds_create(void)
{
int i;
- struct deferred_set *ds;
+ struct dm_deferred_set *ds;
ds = kmalloc(sizeof(*ds), GFP_KERNEL);
@@ -325,18 +325,18 @@ struct deferred_set *ds_create(void)
return ds;
}
-EXPORT_SYMBOL_GPL(ds_create);
+EXPORT_SYMBOL_GPL(dm_ds_create);
-void ds_destroy(struct deferred_set *ds)
+void dm_ds_destroy(struct dm_deferred_set *ds)
{
kfree(ds);
}
-EXPORT_SYMBOL_GPL(ds_destroy);
+EXPORT_SYMBOL_GPL(dm_ds_destroy);
-struct deferred_entry *ds_inc(struct deferred_set *ds)
+struct dm_deferred_entry *dm_ds_inc(struct dm_deferred_set *ds)
{
unsigned long flags;
- struct deferred_entry *entry;
+ struct dm_deferred_entry *entry;
spin_lock_irqsave(&ds->lock, flags);
entry = ds->entries + ds->current_entry;
@@ -345,14 +345,14 @@ struct deferred_entry *ds_inc(struct deferred_set *ds)
return entry;
}
-EXPORT_SYMBOL_GPL(ds_inc);
+EXPORT_SYMBOL_GPL(dm_ds_inc);
static unsigned ds_next(unsigned index)
{
return (index + 1) % DEFERRED_SET_SIZE;
}
-static void __sweep(struct deferred_set *ds, struct list_head *head)
+static void __sweep(struct dm_deferred_set *ds, struct list_head *head)
{
while ((ds->sweeper != ds->current_entry) &&
!ds->entries[ds->sweeper].count) {
@@ -364,7 +364,7 @@ static void __sweep(struct deferred_set *ds, struct list_head *head)
list_splice_init(&ds->entries[ds->sweeper].work_items, head);
}
-void ds_dec(struct deferred_entry *entry, struct list_head *head)
+void dm_ds_dec(struct dm_deferred_entry *entry, struct list_head *head)
{
unsigned long flags;
@@ -374,12 +374,12 @@ void ds_dec(struct deferred_entry *entry, struct list_head *head)
__sweep(entry->ds, head);
spin_unlock_irqrestore(&entry->ds->lock, flags);
}
-EXPORT_SYMBOL_GPL(ds_dec);
+EXPORT_SYMBOL_GPL(dm_ds_dec);
/*
* Returns 1 if deferred or 0 if no pending items to delay job.
*/
-int ds_add_work(struct deferred_set *ds, struct list_head *work)
+int dm_ds_add_work(struct dm_deferred_set *ds, struct list_head *work)
{
int r = 1;
unsigned long flags;
@@ -399,7 +399,7 @@ int ds_add_work(struct deferred_set *ds, struct list_head *work)
return r;
}
-EXPORT_SYMBOL_GPL(ds_add_work);
+EXPORT_SYMBOL_GPL(dm_ds_add_work);
/*----------------------------------------------------------------*/
diff --git a/drivers/md/dm-bio-prison.h b/drivers/md/dm-bio-prison.h
index 0d9d270..76bf9c7 100644
--- a/drivers/md/dm-bio-prison.h
+++ b/drivers/md/dm-bio-prison.h
@@ -15,26 +15,24 @@
/*----------------------------------------------------------------*/
-/* FIXME: prefix everything */
-
/*
* 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 bio_prison;
+struct dm_bio_prison;
struct dm_bio_prison_cell;
/* FIXME: this needs to be more abstract */
-struct cell_key {
+struct dm_cell_key {
int virtual;
dm_thin_id dev;
dm_block_t block;
};
-struct bio_prison *prison_create(unsigned nr_cells);
-void prison_destroy(struct bio_prison *prison);
+struct dm_bio_prison *dm_bio_prison_create(unsigned nr_cells);
+void dm_bio_prison_destroy(struct dm_bio_prison *prison);
/*
* This may block if a new cell needs allocating. You must ensure that
@@ -42,15 +40,15 @@ void prison_destroy(struct bio_prison *prison);
*
* Returns 1 if the cell was already held, 0 if @inmate is the new holder.
*/
-int bio_detain(struct bio_prison *prison, struct cell_key *key,
- struct bio *inmate, struct dm_bio_prison_cell **ref);
-int bio_detain_if_occupied(struct bio_prison *prison, struct cell_key *key,
- struct bio *inmate);
+int dm_bio_detain(struct dm_bio_prison *prison, struct dm_cell_key *key,
+ struct bio *inmate, struct dm_bio_prison_cell **ref);
+int dm_bio_detain_if_occupied(struct dm_bio_prison *prison, struct dm_cell_key *key,
+ struct bio *inmate);
-void cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios);
-void cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio); // FIXME: bio arg not needed
-void cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates);
-void cell_error(struct dm_bio_prison_cell *cell);
+void dm_cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios);
+void dm_cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio); // FIXME: bio arg not needed
+void dm_cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates);
+void dm_cell_error(struct dm_bio_prison_cell *cell);
/*----------------------------------------------------------------*/
@@ -61,15 +59,15 @@ void cell_error(struct dm_bio_prison_cell *cell);
* new mapping could free the old block that the read bios are mapped to.
*/
-struct deferred_set;
-struct deferred_entry;
+struct dm_deferred_set;
+struct dm_deferred_entry;
-struct deferred_set *ds_create(void);
-void ds_destroy(struct deferred_set *ds);
+struct dm_deferred_set *dm_ds_create(void);
+void dm_ds_destroy(struct dm_deferred_set *ds);
-struct deferred_entry *ds_inc(struct deferred_set *ds);
-void ds_dec(struct deferred_entry *entry, struct list_head *head);
-int ds_add_work(struct deferred_set *ds, struct list_head *work);
+struct dm_deferred_entry *dm_ds_inc(struct dm_deferred_set *ds);
+void dm_ds_dec(struct dm_deferred_entry *entry, struct list_head *head);
+int dm_ds_add_work(struct dm_deferred_set *ds, struct list_head *work);
/*----------------------------------------------------------------*/
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 1d4831f..ef9ce66 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -102,7 +102,7 @@
* Key building.
*/
static void build_data_key(struct dm_thin_device *td,
- dm_block_t b, struct cell_key *key)
+ dm_block_t b, struct dm_cell_key *key)
{
key->virtual = 0;
key->dev = dm_thin_dev_id(td);
@@ -110,7 +110,7 @@ static void build_data_key(struct dm_thin_device *td,
}
static void build_virtual_key(struct dm_thin_device *td, dm_block_t b,
- struct cell_key *key)
+ struct dm_cell_key *key)
{
key->virtual = 1;
key->dev = dm_thin_dev_id(td);
@@ -163,7 +163,7 @@ struct pool {
unsigned low_water_triggered:1; /* A dm event has been sent */
unsigned no_free_space:1; /* A -ENOSPC warning has been issued */
- struct bio_prison *prison;
+ struct dm_bio_prison *prison;
struct dm_kcopyd_client *copier;
struct workqueue_struct *wq;
@@ -181,8 +181,8 @@ struct pool {
struct bio_list retry_on_resume_list;
- struct deferred_set *shared_read_ds;
- struct deferred_set *all_io_ds;
+ struct dm_deferred_set *shared_read_ds;
+ struct dm_deferred_set *all_io_ds;
struct dm_thin_new_mapping *next_mapping;
mempool_t *mapping_pool;
@@ -289,8 +289,8 @@ static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev
struct dm_thin_endio_hook {
struct thin_c *tc;
- struct deferred_entry *shared_read_entry;
- struct deferred_entry *all_io_entry;
+ struct dm_deferred_entry *shared_read_entry;
+ struct dm_deferred_entry *all_io_entry;
struct dm_thin_new_mapping *overwrite_mapping;
};
@@ -506,7 +506,7 @@ static void cell_defer(struct thin_c *tc, struct dm_bio_prison_cell *cell,
unsigned long flags;
spin_lock_irqsave(&pool->lock, flags);
- cell_release(cell, &pool->deferred_bios);
+ dm_cell_release(cell, &pool->deferred_bios);
spin_unlock_irqrestore(&tc->pool->lock, flags);
wake_worker(pool);
@@ -525,7 +525,7 @@ static void cell_defer_except(struct thin_c *tc, struct dm_bio_prison_cell *cell
bio_list_init(&bios);
spin_lock_irqsave(&pool->lock, flags);
- cell_release_no_holder(cell, &pool->deferred_bios);
+ dm_cell_release_no_holder(cell, &pool->deferred_bios);
spin_unlock_irqrestore(&pool->lock, flags);
wake_worker(pool);
@@ -535,7 +535,7 @@ static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
{
if (m->bio)
m->bio->bi_end_io = m->saved_bi_end_io;
- cell_error(m->cell);
+ dm_cell_error(m->cell);
list_del(&m->list);
mempool_free(m, m->tc->pool->mapping_pool);
}
@@ -550,7 +550,7 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m)
bio->bi_end_io = m->saved_bi_end_io;
if (m->err) {
- cell_error(m->cell);
+ dm_cell_error(m->cell);
goto out;
}
@@ -562,7 +562,7 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m)
r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);
if (r) {
DMERR("dm_thin_insert_block() failed");
- cell_error(m->cell);
+ dm_cell_error(m->cell);
goto out;
}
@@ -696,7 +696,7 @@ static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
m->err = 0;
m->bio = NULL;
- if (!ds_add_work(pool->shared_read_ds, &m->list))
+ if (!dm_ds_add_work(pool->shared_read_ds, &m->list))
m->quiesced = 1;
/*
@@ -728,7 +728,7 @@ static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
if (r < 0) {
mempool_free(m, pool->mapping_pool);
DMERR("dm_kcopyd_copy() failed");
- cell_error(cell);
+ dm_cell_error(cell);
}
}
}
@@ -793,7 +793,7 @@ static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
if (r < 0) {
mempool_free(m, pool->mapping_pool);
DMERR("dm_kcopyd_zero() failed");
- cell_error(cell);
+ dm_cell_error(cell);
}
}
}
@@ -905,7 +905,7 @@ static void no_space(struct dm_bio_prison_cell *cell)
struct bio_list bios;
bio_list_init(&bios);
- cell_release(cell, &bios);
+ dm_cell_release(cell, &bios);
while ((bio = bio_list_pop(&bios)))
retry_on_resume(bio);
@@ -917,13 +917,13 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
unsigned long flags;
struct pool *pool = tc->pool;
struct dm_bio_prison_cell *cell, *cell2;
- struct cell_key key, key2;
+ struct dm_cell_key key, key2;
dm_block_t block = get_bio_block(tc, bio);
struct dm_thin_lookup_result lookup_result;
struct dm_thin_new_mapping *m;
build_virtual_key(tc->td, block, &key);
- if (bio_detain(tc->pool->prison, &key, bio, &cell))
+ if (dm_bio_detain(tc->pool->prison, &key, bio, &cell))
return;
r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
@@ -935,8 +935,8 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
* on this block.
*/
build_data_key(tc->td, lookup_result.block, &key2);
- if (bio_detain(tc->pool->prison, &key2, bio, &cell2)) {
- cell_release_singleton(cell, bio);
+ if (dm_bio_detain(tc->pool->prison, &key2, bio, &cell2)) {
+ dm_cell_release_singleton(cell, bio);
break;
}
@@ -955,7 +955,7 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
m->err = 0;
m->bio = bio;
- if (!ds_add_work(pool->all_io_ds, &m->list)) {
+ if (!dm_ds_add_work(pool->all_io_ds, &m->list)) {
spin_lock_irqsave(&pool->lock, flags);
list_add(&m->list, &pool->prepared_discards);
spin_unlock_irqrestore(&pool->lock, flags);
@@ -967,8 +967,8 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
* a block boundary. So we submit the discard of a
* partial block appropriately.
*/
- cell_release_singleton(cell, bio);
- cell_release_singleton(cell2, bio);
+ dm_cell_release_singleton(cell, bio);
+ dm_cell_release_singleton(cell2, bio);
if ((!lookup_result.shared) && pool->pf.discard_passdown)
remap_and_issue(tc, bio, lookup_result.block);
else
@@ -980,20 +980,20 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
/*
* It isn't provisioned, just forget it.
*/
- cell_release_singleton(cell, bio);
+ dm_cell_release_singleton(cell, bio);
bio_endio(bio, 0);
break;
default:
DMERR("discard: find block unexpectedly returned %d", r);
- cell_release_singleton(cell, bio);
+ dm_cell_release_singleton(cell, bio);
bio_io_error(bio);
break;
}
}
static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
- struct cell_key *key,
+ struct dm_cell_key *key,
struct dm_thin_lookup_result *lookup_result,
struct dm_bio_prison_cell *cell)
{
@@ -1013,7 +1013,7 @@ static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
default:
DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);
- cell_error(cell);
+ dm_cell_error(cell);
break;
}
}
@@ -1024,14 +1024,14 @@ static void process_shared_bio(struct thin_c *tc, struct bio *bio,
{
struct dm_bio_prison_cell *cell;
struct pool *pool = tc->pool;
- struct cell_key key;
+ struct dm_cell_key key;
/*
* If cell is already occupied, then sharing is already in the process
* of being broken so we have nothing further to do here.
*/
build_data_key(tc->td, lookup_result->block, &key);
- if (bio_detain(pool->prison, &key, bio, &cell))
+ if (dm_bio_detain(pool->prison, &key, bio, &cell))
return;
if (bio_data_dir(bio) == WRITE && bio->bi_size)
@@ -1039,9 +1039,9 @@ static void process_shared_bio(struct thin_c *tc, struct bio *bio,
else {
struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;
- h->shared_read_entry = ds_inc(pool->shared_read_ds);
+ h->shared_read_entry = dm_ds_inc(pool->shared_read_ds);
- cell_release_singleton(cell, bio);
+ dm_cell_release_singleton(cell, bio);
remap_and_issue(tc, bio, lookup_result->block);
}
}
@@ -1056,7 +1056,7 @@ static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block
* Remap empty bios (flushes) immediately, without provisioning.
*/
if (!bio->bi_size) {
- cell_release_singleton(cell, bio);
+ dm_cell_release_singleton(cell, bio);
remap_and_issue(tc, bio, 0);
return;
}
@@ -1066,7 +1066,7 @@ static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block
*/
if (bio_data_dir(bio) == READ) {
zero_fill_bio(bio);
- cell_release_singleton(cell, bio);
+ dm_cell_release_singleton(cell, bio);
bio_endio(bio, 0);
return;
}
@@ -1087,7 +1087,7 @@ static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block
default:
DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);
set_pool_mode(tc->pool, PM_READ_ONLY);
- cell_error(cell);
+ dm_cell_error(cell);
break;
}
}
@@ -1097,7 +1097,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio)
int r;
dm_block_t block = get_bio_block(tc, bio);
struct dm_bio_prison_cell *cell;
- struct cell_key key;
+ struct dm_cell_key key;
struct dm_thin_lookup_result lookup_result;
/*
@@ -1105,7 +1105,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio)
* being provisioned so we have nothing further to do here.
*/
build_virtual_key(tc->td, block, &key);
- if (bio_detain(tc->pool->prison, &key, bio, &cell))
+ if (dm_bio_detain(tc->pool->prison, &key, bio, &cell))
return;
r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
@@ -1120,7 +1120,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio)
* TODO: this will probably have to change when discard goes
* back in.
*/
- cell_release_singleton(cell, bio);
+ dm_cell_release_singleton(cell, bio);
if (lookup_result.shared)
process_shared_bio(tc, bio, block, &lookup_result);
@@ -1130,7 +1130,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio)
case -ENODATA:
if (bio_data_dir(bio) == READ && tc->origin_dev) {
- cell_release_singleton(cell, bio);
+ dm_cell_release_singleton(cell, bio);
remap_to_origin_and_issue(tc, bio);
} else
provision_block(tc, bio, block, cell);
@@ -1138,7 +1138,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio)
default:
DMERR("dm_thin_find_block() failed, error = %d", r);
- cell_release_singleton(cell, bio);
+ dm_cell_release_singleton(cell, bio);
bio_io_error(bio);
break;
}
@@ -1347,7 +1347,7 @@ static struct dm_thin_endio_hook *thin_hook_bio(struct thin_c *tc, struct bio *b
h->tc = tc;
h->shared_read_entry = NULL;
- h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : ds_inc(pool->all_io_ds);
+ h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : dm_ds_inc(pool->all_io_ds);
h->overwrite_mapping = NULL;
return h;
@@ -1557,7 +1557,7 @@ static void __pool_destroy(struct pool *pool)
if (dm_pool_metadata_close(pool->pmd) < 0)
DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
- prison_destroy(pool->prison);
+ dm_bio_prison_destroy(pool->prison);
dm_kcopyd_client_destroy(pool->copier);
if (pool->wq)
@@ -1567,8 +1567,8 @@ static void __pool_destroy(struct pool *pool)
mempool_free(pool->next_mapping, pool->mapping_pool);
mempool_destroy(pool->mapping_pool);
mempool_destroy(pool->endio_hook_pool);
- ds_destroy(pool->shared_read_ds);
- ds_destroy(pool->all_io_ds);
+ dm_ds_destroy(pool->shared_read_ds);
+ dm_ds_destroy(pool->all_io_ds);
kfree(pool);
}
@@ -1607,7 +1607,7 @@ static struct pool *pool_create(struct mapped_device *pool_md,
pool->sectors_per_block_shift = __ffs(block_size);
pool->low_water_blocks = 0;
pool_features_init(&pool->pf);
- pool->prison = prison_create(PRISON_CELLS);
+ pool->prison = dm_bio_prison_create(PRISON_CELLS);
if (!pool->prison) {
*error = "Error creating pool's bio prison";
err_p = ERR_PTR(-ENOMEM);
@@ -1644,11 +1644,11 @@ static struct pool *pool_create(struct mapped_device *pool_md,
pool->no_free_space = 0;
bio_list_init(&pool->retry_on_resume_list);
- pool->shared_read_ds = ds_create();
+ pool->shared_read_ds = dm_ds_create();
if (!pool->shared_read_ds)
goto bad_shared_ds;
- pool->all_io_ds = ds_create();
+ pool->all_io_ds = dm_ds_create();
if (!pool->all_io_ds)
goto bad_all_io_ds;
@@ -1679,15 +1679,15 @@ static struct pool *pool_create(struct mapped_device *pool_md,
bad_endio_hook_pool:
mempool_destroy(pool->mapping_pool);
bad_mapping_pool:
- ds_destroy(pool->all_io_ds);
+ dm_ds_destroy(pool->all_io_ds);
bad_all_io_ds:
- ds_destroy(pool->shared_read_ds);
+ dm_ds_destroy(pool->shared_read_ds);
bad_shared_ds:
destroy_workqueue(pool->wq);
bad_wq:
dm_kcopyd_client_destroy(pool->copier);
bad_kcopyd_client:
- prison_destroy(pool->prison);
+ dm_bio_prison_destroy(pool->prison);
bad_prison:
kfree(pool);
bad_pool:
@@ -2624,7 +2624,7 @@ static int thin_endio(struct dm_target *ti,
if (h->shared_read_entry) {
INIT_LIST_HEAD(&work);
- ds_dec(h->shared_read_entry, &work);
+ dm_ds_dec(h->shared_read_entry, &work);
spin_lock_irqsave(&pool->lock, flags);
list_for_each_entry_safe(m, tmp, &work, list) {
@@ -2637,7 +2637,7 @@ static int thin_endio(struct dm_target *ti,
if (h->all_io_entry) {
INIT_LIST_HEAD(&work);
- ds_dec(h->all_io_entry, &work);
+ dm_ds_dec(h->all_io_entry, &work);
spin_lock_irqsave(&pool->lock, flags);
list_for_each_entry_safe(m, tmp, &work, list)
list_add(&m->list, &pool->prepared_discards);
--
1.7.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-09-25 22:35 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-09-25 22:35 [PATCH 1/3] dm bio prison: factor bio prison code out to standalone library Mike Snitzer
2012-09-25 22:35 ` [PATCH 2/3] dm thin: remove old bio prison code that now lives in dm-bio-prison.c Mike Snitzer
2012-09-25 22:35 ` [PATCH 3/3] dm bio prison: add "dm_" prefix to bio prison and deferred set interfaces Mike Snitzer
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).