diff options
| -rw-r--r-- | drivers/md/dm-ioctl.c | 13 | ||||
| -rw-r--r-- | drivers/md/dm-table.c | 111 | ||||
| -rw-r--r-- | drivers/md/dm.c | 162 | ||||
| -rw-r--r-- | drivers/md/dm.h | 25 |
4 files changed, 285 insertions, 26 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 1c871736f48c..7f77f18fcafa 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1050,6 +1050,12 @@ static int populate_table(struct dm_table *table, next = spec->next; } + r = dm_table_set_type(table); + if (r) { + DMWARN("unable to set table type"); + return r; + } + return dm_table_complete(table); } @@ -1095,6 +1101,13 @@ static int table_load(struct dm_ioctl *param, size_t param_size) goto out; } + r = dm_table_alloc_md_mempools(t); + if (r) { + DMWARN("unable to allocate mempools for this table"); + dm_table_destroy(t); + goto out; + } + down_write(&_hash_lock); hc = dm_get_mdptr(md); if (!hc || hc->md != md) { diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index c5f784419f23..aaeb82ed2852 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -41,6 +41,7 @@ struct dm_table { struct mapped_device *md; atomic_t holders; + unsigned type; /* btree table */ unsigned int depth; @@ -65,6 +66,8 @@ struct dm_table { /* events get handed up using this callback */ void (*event_fn)(void *); void *event_context; + + struct dm_md_mempools *mempools; }; /* @@ -258,6 +261,8 @@ void dm_table_destroy(struct dm_table *t) if (t->devices.next != &t->devices) free_devices(&t->devices); + dm_free_md_mempools(t->mempools); + kfree(t); } @@ -764,6 +769,99 @@ int dm_table_add_target(struct dm_table *t, const char *type, return r; } +int dm_table_set_type(struct dm_table *t) +{ + unsigned i; + unsigned bio_based = 0, request_based = 0; + struct dm_target *tgt; + struct dm_dev_internal *dd; + struct list_head *devices; + + for (i = 0; i < t->num_targets; i++) { + tgt = t->targets + i; + if (dm_target_request_based(tgt)) + request_based = 1; + else + bio_based = 1; + + if (bio_based && request_based) { + DMWARN("Inconsistent table: different target types" + " can't be mixed up"); + return -EINVAL; + } + } + + if (bio_based) { + /* We must use this table as bio-based */ + t->type = DM_TYPE_BIO_BASED; + return 0; + } + + BUG_ON(!request_based); /* No targets in this table */ + + /* Non-request-stackable devices can't be used for request-based dm */ + devices = dm_table_get_devices(t); + list_for_each_entry(dd, devices, list) { + if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) { + DMWARN("table load rejected: including" + " non-request-stackable devices"); + return -EINVAL; + } + } + + /* + * Request-based dm supports only tables that have a single target now. + * To support multiple targets, request splitting support is needed, + * and that needs lots of changes in the block-layer. + * (e.g. request completion process for partial completion.) + */ + if (t->num_targets > 1) { + DMWARN("Request-based dm doesn't support multiple targets yet"); + return -EINVAL; + } + + t->type = DM_TYPE_REQUEST_BASED; + + return 0; +} + +unsigned dm_table_get_type(struct dm_table *t) +{ + return t->type; +} + +bool dm_table_request_based(struct dm_table *t) +{ + return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED; +} + +int dm_table_alloc_md_mempools(struct dm_table *t) +{ + unsigned type = dm_table_get_type(t); + + if (unlikely(type == DM_TYPE_NONE)) { + DMWARN("no table type is set, can't allocate mempools"); + return -EINVAL; + } + + t->mempools = dm_alloc_md_mempools(type); + if (!t->mempools) + return -ENOMEM; + + return 0; +} + +void dm_table_free_md_mempools(struct dm_table *t) +{ + dm_free_md_mempools(t->mempools); + t->mempools = NULL; +} + +struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t) +{ + return t->mempools; +} + static int setup_indexes(struct dm_table *t) { int i; @@ -985,6 +1083,19 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q); dm_table_set_integrity(t); + + /* + * QUEUE_FLAG_STACKABLE must be set after all queue settings are + * visible to other CPUs because, once the flag is set, incoming bios + * are processed by request-based dm, which refers to the queue + * settings. + * Until the flag set, bios are passed to bio-based dm and queued to + * md->deferred where queue settings are not needed yet. + * Those bios are passed to request-based dm at the resume time. + */ + smp_mb(); + if (dm_table_request_based(t)) + queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q); } unsigned int dm_table_get_num_targets(struct dm_table *t) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index be003e5fea3d..5a843c1f4d64 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -190,6 +190,15 @@ struct mapped_device { struct bio barrier_bio; }; +/* + * For mempools pre-allocation at the table loading time. + */ +struct dm_md_mempools { + mempool_t *io_pool; + mempool_t *tio_pool; + struct bio_set *bs; +}; + #define MIN_IOS 256 static struct kmem_cache *_io_cache; static struct kmem_cache *_tio_cache; @@ -1739,10 +1748,22 @@ static struct mapped_device *alloc_dev(int minor) INIT_LIST_HEAD(&md->uevent_list); spin_lock_init(&md->uevent_lock); - md->queue = blk_alloc_queue(GFP_KERNEL); + md->queue = blk_init_queue(dm_request_fn, NULL); if (!md->queue) goto bad_queue; + /* + * Request-based dm devices cannot be stacked on top of bio-based dm + * devices. The type of this dm device has not been decided yet, + * although we initialized the queue using blk_init_queue(). + * The type is decided at the first table loading time. + * To prevent problematic device stacking, clear the queue flag + * for request stacking support until then. + * + * This queue is new, so no concurrency on the queue_flags. + */ + queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue); + md->saved_make_request_fn = md->queue->make_request_fn; md->queue->queuedata = md; md->queue->backing_dev_info.congested_fn = dm_any_congested; md->queue->backing_dev_info.congested_data = md; @@ -1751,18 +1772,9 @@ static struct mapped_device *alloc_dev(int minor) blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); md->queue->unplug_fn = dm_unplug_all; blk_queue_merge_bvec(md->queue, dm_merge_bvec); - - md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); - if (!md->io_pool) - goto bad_io_pool; - - md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); - if (!md->tio_pool) - goto bad_tio_pool; - - md->bs = bioset_create(16, 0); - if (!md->bs) - goto bad_no_bioset; + blk_queue_softirq_done(md->queue, dm_softirq_done); + blk_queue_prep_rq(md->queue, dm_prep_fn); + blk_queue_lld_busy(md->queue, dm_lld_busy); md->disk = alloc_disk(1); if (!md->disk) @@ -1804,12 +1816,6 @@ bad_bdev: bad_thread: put_disk(md->disk); bad_disk: - bioset_free(md->bs); -bad_no_bioset: - mempool_destroy(md->tio_pool); -bad_tio_pool: - mempool_destroy(md->io_pool); -bad_io_pool: blk_cleanup_queue(md->queue); bad_queue: free_minor(minor); @@ -1829,9 +1835,12 @@ static void free_dev(struct mapped_device *md) unlock_fs(md); bdput(md->bdev); destroy_workqueue(md->wq); - mempool_destroy(md->tio_pool); - mempool_destroy(md->io_pool); - bioset_free(md->bs); + if (md->tio_pool) + mempool_destroy(md->tio_pool); + if (md->io_pool) + mempool_destroy(md->io_pool); + if (md->bs) + bioset_free(md->bs); blk_integrity_unregister(md->disk); del_gendisk(md->disk); free_minor(minor); @@ -1846,6 +1855,29 @@ static void free_dev(struct mapped_device *md) kfree(md); } +static void __bind_mempools(struct mapped_device *md, struct dm_table *t) +{ + struct dm_md_mempools *p; + + if (md->io_pool && md->tio_pool && md->bs) + /* the md already has necessary mempools */ + goto out; + + p = dm_table_get_md_mempools(t); + BUG_ON(!p || md->io_pool || md->tio_pool || md->bs); + + md->io_pool = p->io_pool; + p->io_pool = NULL; + md->tio_pool = p->tio_pool; + p->tio_pool = NULL; + md->bs = p->bs; + p->bs = NULL; + +out: + /* mempool bind completed, now no need any mempools in the table */ + dm_table_free_md_mempools(t); +} + /* * Bind a table to the device. */ @@ -1897,6 +1929,18 @@ static int __bind(struct mapped_device *md, struct dm_table *t, dm_table_event_callback(t, event_callback, md); + /* + * The queue hasn't been stopped yet, if the old table type wasn't + * for request-based during suspension. So stop it to prevent + * I/O mapping before resume. + * This must be done before setting the queue restrictions, + * because request-based dm may be run just after the setting. + */ + if (dm_table_request_based(t) && !blk_queue_stopped(q)) + stop_queue(q); + + __bind_mempools(md, t); + write_lock(&md->map_lock); md->map = t; dm_table_set_restrictions(t, q, limits); @@ -2110,10 +2154,14 @@ static void dm_wq_work(struct work_struct *work) up_write(&md->io_lock); - if (bio_barrier(c)) - process_barrier(md, c); - else - __split_and_process_bio(md, c); + if (dm_request_based(md)) + generic_make_request(c); + else { + if (bio_barrier(c)) + process_barrier(md, c); + else + __split_and_process_bio(md, c); + } down_write(&md->io_lock); } @@ -2146,6 +2194,13 @@ int dm_swap_table(struct mapped_device *md, struct dm_table *table) if (r) goto out; + /* cannot change the device type, once a table is bound */ + if (md->map && + (dm_table_get_type(md->map) != dm_table_get_type(table))) { + DMWARN("can't change the device type after a table is bound"); + goto out; + } + __unbind(md); r = __bind(md, table, &limits); @@ -2542,6 +2597,61 @@ int dm_noflush_suspending(struct dm_target *ti) } EXPORT_SYMBOL_GPL(dm_noflush_suspending); +struct dm_md_mempools *dm_alloc_md_mempools(unsigned type) +{ + struct dm_md_mempools *pools = kmalloc(sizeof(*pools), GFP_KERNEL); + + if (!pools) + return NULL; + + pools->io_pool = (type == DM_TYPE_BIO_BASED) ? + mempool_create_slab_pool(MIN_IOS, _io_cache) : + mempool_create_slab_pool(MIN_IOS, _rq_bio_info_cache); + if (!pools->io_pool) + goto free_pools_and_out; + + pools->tio_pool = (type == DM_TYPE_BIO_BASED) ? + mempool_create_slab_pool(MIN_IOS, _tio_cache) : + mempool_create_slab_pool(MIN_IOS, _rq_tio_cache); + if (!pools->tio_pool) + goto free_io_pool_and_out; + + pools->bs = (type == DM_TYPE_BIO_BASED) ? + bioset_create(16, 0) : bioset_create(MIN_IOS, 0); + if (!pools->bs) + goto free_tio_pool_and_out; + + return pools; + +free_tio_pool_and_out: + mempool_destroy(pools->tio_pool); + +free_io_pool_and_out: + mempool_destroy(pools->io_pool); + +free_pools_and_out: + kfree(pools); + + return NULL; +} + +void dm_free_md_mempools(struct dm_md_mempools *pools) +{ + if (!pools) + return; + + if (pools->io_pool) + mempool_destroy(pools->io_pool); + + if (pools->tio_pool) + mempool_destroy(pools->tio_pool); + + if (pools->bs) + bioset_free(pools->bs); + + kfree(pools); +} + static struct block_device_operations dm_blk_dops = { .open = dm_blk_open, .release = dm_blk_close, diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 8dcabb1caff1..a7663eba17e2 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -23,6 +23,13 @@ #define DM_SUSPEND_NOFLUSH_FLAG (1 << 1) /* + * Type of table and mapped_device's mempool + */ +#define DM_TYPE_NONE 0 +#define DM_TYPE_BIO_BASED 1 +#define DM_TYPE_REQUEST_BASED 2 + +/* * List of devices that a metadevice uses and should open/close. */ struct dm_dev_internal { @@ -32,6 +39,7 @@ struct dm_dev_internal { }; struct dm_table; +struct dm_md_mempools; /*----------------------------------------------------------------- * Internal table functions. @@ -51,12 +59,23 @@ void dm_table_postsuspend_targets(struct dm_table *t); int dm_table_resume_targets(struct dm_table *t); int dm_table_any_congested(struct dm_table *t, int bdi_bits); int dm_table_any_busy_target(struct dm_table *t); +int dm_table_set_type(struct dm_table *t); +unsigned dm_table_get_type(struct dm_table *t); +bool dm_table_request_based(struct dm_table *t); +int dm_table_alloc_md_mempools(struct dm_table *t); +void dm_table_free_md_mempools(struct dm_table *t); +struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t); /* * To check the return value from dm_table_find_target(). */ #define dm_target_is_valid(t) ((t)->table) +/* + * To check whether the target type is request-based or not (bio-based). + */ +#define dm_target_request_based(t) ((t)->type->map_rq != NULL) + /*----------------------------------------------------------------- * A registry of target types. *---------------------------------------------------------------*/ @@ -102,4 +121,10 @@ void dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, int dm_kcopyd_init(void); void dm_kcopyd_exit(void); +/* + * Mempool operations + */ +struct dm_md_mempools *dm_alloc_md_mempools(unsigned type); +void dm_free_md_mempools(struct dm_md_mempools *pools); + #endif |
