From: Mikulas Patocka Here I'm sending the patch for dm statistics. (it depends on the RCU patch, but it could be trivially fixed to apply without the RCU patch - see functions dm_internal_suspend and dm_internal_resume). --- Documentation/device-mapper/dm-statistics.txt | 44 ++ drivers/md/Makefile | 2 drivers/md/dm-ioctl.c | 144 ++++++++ drivers/md/dm-stats.c | 430 ++++++++++++++++++++++++++ drivers/md/dm-stats.h | 38 ++ drivers/md/dm.c | 48 ++ drivers/md/dm.h | 8 include/uapi/linux/dm-ioctl.h | 5 8 files changed, 716 insertions(+), 3 deletions(-) Index: linux/Documentation/device-mapper/dm-statistics.txt =================================================================== --- /dev/null +++ linux/Documentation/device-mapper/dm-statistics.txt @@ -0,0 +1,44 @@ +dm statistics + +Device mapper can calculate I/O statistics on various regions of +the device. + +Each region specifies a starting sector, ending sector and step. +Individual statistics will be collected for each step-sized area +between starting and ending sector. + +Each region is identified by a region id, it is integer number that is +uniquely assigned when creating the region. The region number must be +supplied when querying statistics about the region or deleting the +region. Unique region ids enable multiple userspace programs request and +process statistics without stepping over each other's data. + +New region is specified with the following message: +dmsetup message 0 @stats_create + range is + "-" - whole device + "-" - a specified range in 512-byte sectors + step is + "" - the number of sectors in each area + "/" - the range is subdivided into the specified + number of areas +The message returns the region id. + +Statistics can be queried with the following message: +dmsetup message 0 @stats_print +This message returns statistics, each area is represented by one line in +this form: +- counters +Counters have the same meaning as /sys/block/*/stat or /proc/diskstats +The counter of merged requests is always zero because merging has no +meaning in device mapper. + +The message +dmsetup message 0 @stats_print_clear +prints the counters and clears them (except in-flight counter, it +reflects the current number of in-flight requests and it is not +cleared). + +The message +dmsetup message 0 @stats_delete +deletes the range with the specified id. Index: linux/drivers/md/Makefile =================================================================== --- linux.orig/drivers/md/Makefile +++ linux/drivers/md/Makefile @@ -3,7 +3,7 @@ # dm-mod-y += dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \ - dm-ioctl.o dm-io.o dm-kcopyd.o dm-sysfs.o + dm-ioctl.o dm-stats.o dm-io.o dm-kcopyd.o dm-sysfs.o dm-multipath-y += dm-path-selector.o dm-mpath.o dm-snapshot-y += dm-snap.o dm-exception-store.o dm-snap-transient.o \ dm-snap-persistent.o Index: linux/drivers/md/dm-ioctl.c =================================================================== --- linux.orig/drivers/md/dm-ioctl.c +++ linux/drivers/md/dm-ioctl.c @@ -1451,6 +1451,141 @@ static int table_status(struct dm_ioctl return 0; } +struct dm_message_output_callback { + struct dm_ioctl *param; + size_t param_size; +}; + +static int dm_output_message_string(struct dm_message_output_callback *c, + const char *string) +{ + size_t len; + char *p; + if (c->param->flags & DM_BUFFER_FULL_FLAG) + return -1; + if (!(c->param->flags & DM_MESSAGE_OUT_FLAG)) { + p = get_result_buffer(c->param, c->param_size, &len); + if (!len) { + c->param->flags |= DM_BUFFER_FULL_FLAG; + return -1; + } + *p = 0; + c->param->data_size = c->param->data_start + 1; + c->param->flags |= DM_MESSAGE_OUT_FLAG; + } + p = (char *)c->param + c->param->data_size - 1; + len = strlen(string); + if (c->param->data_size + len > c->param_size) { + c->param->flags |= DM_BUFFER_FULL_FLAG; + c->param->flags &= ~DM_MESSAGE_OUT_FLAG; + return -1; + } + c->param->data_size += len; + strcpy(p, string); + return 0; +} + +/* + * Process device-mapper dependent messages. + * Returns a number <= 0 if message was processed by device mapper. + * Returns 1 if message should be delivered to the target. + */ +static int message_for_md(struct mapped_device *md, + struct dm_message_output_callback *c, + unsigned argc, char **argv) +{ + int id; + char dummy; + if (!strcasecmp(argv[0], "@stats_create")) { + unsigned long long start, end, step; + unsigned div; + char id_string[11]; + + if (dm_request_based(md)) + goto no_rq_based_stats; + + if (argc != 3) + goto invalid_message; + + if (!strcmp(argv[1], "-")) { + start = 0; + end = dm_get_size(md); + if (!end) + end = 1; + } else if (sscanf(argv[1], "%llu-%llu%c", &start, &end, &dummy) != 2 || + start != (sector_t)start || end != (sector_t)end) + goto invalid_message; + + if (start >= end) + goto invalid_message; + + if (sscanf(argv[2], "/%u%c", &div, &dummy) == 1) { + step = end - start; + if (do_div(step, div)) + step++; + if (!step) + step = 1; + } else if (sscanf(argv[2], "%llu%c", &step, &dummy) != 1 || step != (sector_t)step || !step) + goto invalid_message; + + /* + * Suspend/resume to make sure there is no i/o in flight, so that newly + * created statistics will be exact. + */ + dm_internal_suspend(md); + id = dm_stats_create(dm_get_stats(md), start, end, step); + dm_internal_resume(md); + + if (id < 0) + return id; + + snprintf(id_string, sizeof id_string, "%d", id); + dm_output_message_string(c, id_string); + + return 0; + } else if (!strcasecmp(argv[0], "@stats_delete")) { + if (dm_request_based(md)) + goto no_rq_based_stats; + + if (argc != 2) + goto invalid_message; + + if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0) + goto invalid_message; + + return dm_stats_delete(dm_get_stats(md), id); + } else if (!strcasecmp(argv[0], "@stats_print")) { + if (dm_request_based(md)) + goto no_rq_based_stats; + + if (argc != 2) + goto invalid_message; + if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0) + goto invalid_message; + return dm_stats_print(dm_get_stats(md), id, false, c, + dm_output_message_string); + } else if (!strcasecmp(argv[0], "@stats_print_clear")) { + if (dm_request_based(md)) + goto no_rq_based_stats; + + if (argc != 2) + goto invalid_message; + if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0) + goto invalid_message; + return dm_stats_print(dm_get_stats(md), id, true, c, + dm_output_message_string); + } + return 1; + +no_rq_based_stats: + DMWARN("Statistics are only supported for bio based devices"); + return -EOPNOTSUPP; + +invalid_message: + DMWARN("Invalid parameters for message %s", argv[0]); + return -EINVAL; +} + /* * Pass a message to the target that's at the supplied device offset. */ @@ -1463,6 +1598,7 @@ static int target_message(struct dm_ioct struct dm_target *ti; struct dm_target_msg *tmsg = (void *) param + param->data_start; int srcu_idx; + struct dm_message_output_callback c = { param, param_size }; md = find_device(param); if (!md) @@ -1486,6 +1622,10 @@ static int target_message(struct dm_ioct goto out_argv; } + r = message_for_md(md, &c, argc, argv); + if (r <= 0) + goto out_argv; + table = dm_get_live_table(md, &srcu_idx); if (!table) goto out_table; @@ -1511,7 +1651,8 @@ static int target_message(struct dm_ioct out_argv: kfree(argv); out: - param->data_size = 0; + if (!(param->flags & (DM_MESSAGE_OUT_FLAG | DM_BUFFER_FULL_FLAG))) + param->data_size = 0; dm_put(md); return r; } @@ -1691,6 +1832,7 @@ static int validate_params(uint cmd, str param->flags &= ~DM_BUFFER_FULL_FLAG; param->flags &= ~DM_UEVENT_GENERATED_FLAG; param->flags &= ~DM_SECURE_DATA_FLAG; + param->flags &= ~DM_MESSAGE_OUT_FLAG; /* Ignores parameters */ if (cmd == DM_REMOVE_ALL_CMD || Index: linux/drivers/md/dm-stats.c =================================================================== --- /dev/null +++ linux/drivers/md/dm-stats.c @@ -0,0 +1,430 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "dm-stats.h" + +static volatile int dm_stat_need_rcu_barrier; + +struct dm_stat_percpu { + unsigned long sectors[2]; + unsigned long ios[2]; + unsigned long ticks[2]; + unsigned long io_ticks; + unsigned long time_in_queue; +}; + +struct dm_stat_shared { + atomic_t in_flight[2]; + unsigned long stamp; + struct dm_stat_percpu tmp; +}; + +struct dm_stat { + struct list_head list_entry; + int id; + size_t n_entries; + sector_t start; + sector_t end; + sector_t step; + struct rcu_head rcu_head; + struct dm_stat_percpu *stat_percpu[NR_CPUS]; + struct dm_stat_shared stat_shared[0]; +}; + +static void *kvzalloc(size_t alloc_size, int node) +{ + void *p; + if (alloc_size <= KMALLOC_MAX_SIZE) { + p = kzalloc_node(alloc_size, GFP_KERNEL | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN, node); + if (p) + return p; + } + return vzalloc_node(alloc_size, node); +} + +static void kvfree(void *ptr) +{ + if (is_vmalloc_addr(ptr)) + vfree(ptr); + else + kfree(ptr); +} + +static void dm_stat_free(struct rcu_head *head) +{ + struct dm_stat *m = container_of(head, struct dm_stat, rcu_head); + int cpu; + for_each_possible_cpu(cpu) + kvfree(m->stat_percpu[cpu]); + kvfree(m); +} + +static int dm_stat_in_flight(struct dm_stat_shared *s) +{ + return atomic_read(&s->in_flight[0]) + atomic_read(&s->in_flight[1]); +} + +void dm_stats_init_device(struct dm_stats *st) +{ + mutex_init(&st->mutex); + INIT_LIST_HEAD(&st->list); +} + +void dm_stats_exit_device(struct dm_stats *st) +{ + size_t ni; + while (!list_empty(&st->list)) { + struct dm_stat *m = container_of(st->list.next, struct dm_stat, list_entry); + list_del(&m->list_entry); + for (ni = 0; ni < m->n_entries; ni++) { + struct dm_stat_shared *s = &m->stat_shared[ni]; + if (dm_stat_in_flight(s)) { + printk(KERN_CRIT "dm-stats: leaked in-flight counter at index %lu (start %llu, end %llu, step %llu): reads %d, writes %d\n", + (unsigned long)ni, + (unsigned long long)m->start, + (unsigned long long)m->end, + (unsigned long long)m->step, + atomic_read(&s->in_flight[0]), + atomic_read(&s->in_flight[1]) + ); + BUG(); + } + } + dm_stat_free(&m->rcu_head); + } +} + +int dm_stats_create(struct dm_stats *st, sector_t start, sector_t end, sector_t step) +{ + struct list_head *l; + struct dm_stat *s; + sector_t n_entries; + size_t ni; + size_t shared_alloc_size; + size_t percpu_alloc_size; + int cpu; + int ret_id; + + if (end < start || !step) + return -EINVAL; + + n_entries = end - start; + if (sector_div(n_entries, step)) + n_entries++; + + if (n_entries != (size_t)n_entries || !(n_entries + 1)) + return -EOVERFLOW; + + shared_alloc_size = sizeof(struct dm_stat) + (size_t)n_entries * sizeof(struct dm_stat_shared); + if ((shared_alloc_size - sizeof(struct dm_stat)) / sizeof(struct dm_stat_shared) != n_entries) + return -EOVERFLOW; + + percpu_alloc_size = (size_t)n_entries * sizeof(struct dm_stat_percpu); + if (percpu_alloc_size / sizeof(struct dm_stat_percpu) != n_entries) + return -EOVERFLOW; + + s = kvzalloc(shared_alloc_size, NUMA_NO_NODE); + if (!s) + return -ENOMEM; + + s->n_entries = n_entries; + s->start = start; + s->end = end; + s->step = step; + s->id = 0; + + for (ni = 0; ni < n_entries; ni++) { + atomic_set(&s->stat_shared[ni].in_flight[0], 0); + atomic_set(&s->stat_shared[ni].in_flight[1], 0); + } + + for_each_possible_cpu(cpu) { + struct dm_stat_percpu *pc = kvzalloc(percpu_alloc_size, cpu_to_node(cpu)); + if (!pc) { + dm_stat_free(&s->rcu_head); + return -ENOMEM; + } + s->stat_percpu[cpu] = pc; + } + + mutex_lock(&st->mutex); + list_for_each(l, &st->list) { + struct dm_stat *m = container_of(l, struct dm_stat, list_entry); + if (m->id < s->id) + BUG(); + if (m->id > s->id) + break; + if (s->id == INT_MAX) { + mutex_unlock(&st->mutex); + return -ENFILE; + } + s->id++; + } + ret_id = s->id; + list_add_tail_rcu(&s->list_entry, l); + mutex_unlock(&st->mutex); + + return ret_id; +} + +static struct dm_stat *dm_stats_find(struct dm_stats *st, int id) +{ + struct dm_stat *m; + + mutex_lock(&st->mutex); + + list_for_each_entry(m, &st->list, list_entry) { + if (m->id > id) + break; + if (m->id == id) + return m; + } + + mutex_unlock(&st->mutex); + + return NULL; +} + +int dm_stats_delete(struct dm_stats *st, int id) +{ + struct dm_stat *m; + int cpu; + + m = dm_stats_find(st, id); + if (!m) + return -ENOENT; + + list_del_rcu(&m->list_entry); + mutex_unlock(&st->mutex); + + /* + * vfree can't be called from RCU callback + */ + for_each_possible_cpu(cpu) + if (is_vmalloc_addr(m->stat_percpu)) + goto do_sync_free; + if (is_vmalloc_addr(m)) { +do_sync_free: + synchronize_rcu_expedited(); + dm_stat_free(&m->rcu_head); + } else { + dm_stat_need_rcu_barrier = 1; + call_rcu(&m->rcu_head, dm_stat_free); + } + return 0; +} + +static void dm_stat_round(struct dm_stat_shared *s, struct dm_stat_percpu *p) +{ + /* + * This is racy, but so is part_round_stats_single. + */ + unsigned long now = jiffies; + unsigned inf; + if (now == s->stamp) + return; + inf = dm_stat_in_flight(s); + if (inf) { + p->io_ticks += now - s->stamp; + p->time_in_queue += inf * (now - s->stamp); + } + s->stamp = now; +} + +static void dm_stat_for_entry(struct dm_stat *m, size_t entry, + unsigned long bi_rw, unsigned len, bool end, + unsigned long duration) +{ + unsigned long idx = bi_rw & REQ_WRITE; + struct dm_stat_shared *s = &m->stat_shared[entry]; + struct dm_stat_percpu *p; + + /* + * For strict correctness we should use local_irq_disable/enable + * instead of preempt_disable/enable. + * + * This is racy if the driver finishes bios from non-interrupt + * context as well as from interrupt context or from more different + * interrupts. + * + * However, the race only results in not counting some events, + * so it is acceptable. + * + * part_stat_lock()/part_stat_unlock() have this race too. + */ + preempt_disable(); + p = &m->stat_percpu[smp_processor_id()][entry]; + + if (!end) { + dm_stat_round(s, p); + atomic_inc(&s->in_flight[idx]); + } else { + dm_stat_round(s, p); + atomic_dec(&s->in_flight[idx]); + p->sectors[idx] += len; + p->ios[idx] += 1; + p->ticks[idx] += duration; + } + + preempt_enable(); +} + +static bool dm_stats_should_drop_bio(struct bio *bio) +{ + return !bio->bi_size; +} + +void dm_stats_bio(struct dm_stats *st, struct bio *bio, bool end, + unsigned long duration) +{ + struct dm_stat *m; + sector_t end_sector; + + if (unlikely(dm_stats_should_drop_bio(bio))) + return; + + end_sector = bio->bi_sector + bio_sectors(bio); + + rcu_read_lock(); + + list_for_each_entry_rcu(m, &st->list, list_entry) { + sector_t rel_sector, offset; + unsigned todo; + size_t entry; + if (end_sector <= m->start || bio->bi_sector >= m->end) + continue; + if (unlikely(bio->bi_sector < m->start)) { + rel_sector = 0; + todo = end_sector - m->start; + } else { + rel_sector = bio->bi_sector - m->start; + todo = end_sector - bio->bi_sector; + } + if (unlikely(end_sector > m->end)) + todo -= end_sector - m->end; + offset = sector_div(rel_sector, m->step); + entry = rel_sector; + do { + unsigned fragment_len; + BUG_ON(entry >= m->n_entries); + fragment_len = todo; + if (fragment_len > m->step - offset) + fragment_len = m->step - offset; + dm_stat_for_entry(m, entry, bio->bi_rw, fragment_len, + end, duration); + todo -= fragment_len; + entry++; + offset = 0; + } while (unlikely(todo != 0)); + } + + rcu_read_unlock(); +} + +int dm_stats_print(struct dm_stats *st, int id, bool clear, + struct dm_message_output_callback *c, + int (*callback)(struct dm_message_output_callback *, const char *)) +{ + struct dm_stat *m; + size_t x; + sector_t start, end; + + m = dm_stats_find(st, id); + if (!m) + return -ENOENT; + + start = m->start; + + for (x = 0; x < m->n_entries; x++, start = end) { + int cpu; + struct dm_stat_shared *s = &m->stat_shared[x]; + struct dm_stat_percpu *p; + const int LD = sizeof(unsigned long) > 4 ? 20 : 10; + const int SD = sizeof(sector_t) > 4 ? 20 : 10; + char out_string[SD+1+SD+1+LD+3+LD+1+LD+1+LD+3+LD+1+LD+1+10+1+LD+1+LD+2]; + + end = start + m->step; + if (unlikely(end > m->end)) + end = m->end; + + local_irq_disable(); + p = &m->stat_percpu[smp_processor_id()][x]; + dm_stat_round(s, p); + local_irq_enable(); + + memset(&s->tmp, 0, sizeof s->tmp); + for_each_possible_cpu(cpu) { + p = &m->stat_percpu[cpu][x]; + s->tmp.sectors[0] += p->sectors[0]; + s->tmp.sectors[1] += p->sectors[1]; + s->tmp.ios[0] += p->ios[0]; + s->tmp.ios[1] += p->ios[1]; + s->tmp.ticks[0] += p->ticks[0]; + s->tmp.ticks[1] += p->ticks[1]; + s->tmp.io_ticks += p->io_ticks; + s->tmp.time_in_queue += p->time_in_queue; + } + + snprintf(out_string, sizeof(out_string), + "%llu-%llu %lu %u %lu %lu %lu %u %lu %lu %d %lu %lu\n", + (unsigned long long)start, + (unsigned long long)end, + s->tmp.ios[0], + 0U, + s->tmp.sectors[0], + s->tmp.ticks[0], + s->tmp.ios[1], + 0U, + s->tmp.sectors[1], + s->tmp.ticks[1], + dm_stat_in_flight(s), + s->tmp.io_ticks, + s->tmp.time_in_queue + ); + if (callback(c, out_string)) + goto buffer_overflow; + } + + if (clear) { + for (x = 0; x < m->n_entries; x++) { + struct dm_stat_shared *s = &m->stat_shared[x]; + struct dm_stat_percpu *p; + local_irq_disable(); + p = &m->stat_percpu[smp_processor_id()][x]; + p->sectors[0] -= s->tmp.sectors[0]; + p->sectors[1] -= s->tmp.sectors[1]; + p->ios[0] -= s->tmp.ios[0]; + p->ios[1] -= s->tmp.ios[1]; + p->ticks[0] -= s->tmp.ticks[0]; + p->ticks[1] -= s->tmp.ticks[1]; + p->io_ticks -= s->tmp.io_ticks; + p->time_in_queue -= s->tmp.time_in_queue; + local_irq_enable(); + } + } + +buffer_overflow: + mutex_unlock(&st->mutex); + + return 0; +} + +int __init dm_stats_init(void) +{ + dm_stat_need_rcu_barrier = 0; + return 0; +} + +void dm_stats_exit(void) +{ + if (dm_stat_need_rcu_barrier) + rcu_barrier(); +} Index: linux/drivers/md/dm-stats.h =================================================================== --- /dev/null +++ linux/drivers/md/dm-stats.h @@ -0,0 +1,38 @@ +#ifndef DM_STATS_H +#define DM_STATS_H + +#include +#include +#include +#include +#include + +int dm_stats_init(void); +void dm_stats_exit(void); + +struct dm_stats { + struct mutex mutex; + struct list_head list; /* list of struct dm_stat */ +}; + +void dm_stats_init_device(struct dm_stats *st); +void dm_stats_exit_device(struct dm_stats *st); + +int dm_stats_create(struct dm_stats *st, sector_t start, sector_t end, sector_t step); +int dm_stats_delete(struct dm_stats *st, int id); + +void dm_stats_bio(struct dm_stats *st, struct bio *bio, bool end, + unsigned long duration); + +struct dm_message_output_callback; + +int dm_stats_print(struct dm_stats *st, int id, bool clear, + struct dm_message_output_callback *c, + int (*callback)(struct dm_message_output_callback *, const char *)); + +static inline bool dm_stats_used(struct dm_stats *st) +{ + return !list_empty(&st->list); +} + +#endif Index: linux/drivers/md/dm.c =================================================================== --- linux.orig/drivers/md/dm.c +++ linux/drivers/md/dm.c @@ -176,6 +176,8 @@ struct mapped_device { struct bio_set *bs; + struct dm_stats stats; + /* * Event handling. */ @@ -284,6 +286,7 @@ static int (*_inits[])(void) __initdata dm_io_init, dm_kcopyd_init, dm_interface_init, + dm_stats_init, }; static void (*_exits[])(void) = { @@ -294,6 +297,7 @@ static void (*_exits[])(void) = { dm_io_exit, dm_kcopyd_exit, dm_interface_exit, + dm_stats_exit, }; static int __init dm_init(void) @@ -402,6 +406,16 @@ int dm_lock_for_deletion(struct mapped_d return r; } +sector_t dm_get_size(struct mapped_device *md) +{ + return get_capacity(md->disk); +} + +struct dm_stats *dm_get_stats(struct mapped_device *md) +{ + return &md->stats; +} + static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) { struct mapped_device *md = bdev->bd_disk->private_data; @@ -486,6 +500,9 @@ static void start_io_acct(struct dm_io * part_stat_unlock(); atomic_set(&dm_disk(md)->part0.in_flight[rw], atomic_inc_return(&md->pending[rw])); + + if (unlikely(dm_stats_used(&md->stats))) + dm_stats_bio(&md->stats, io->bio, false, 0); } static void end_io_acct(struct dm_io *io) @@ -501,6 +518,9 @@ static void end_io_acct(struct dm_io *io part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration); part_stat_unlock(); + if (unlikely(dm_stats_used(&md->stats))) + dm_stats_bio(&md->stats, bio, true, duration); + /* * After this is decremented the bio must not be touched if it is * a flush. @@ -1529,7 +1549,7 @@ static void _dm_request(struct request_q return; } -static int dm_request_based(struct mapped_device *md) +int dm_request_based(struct mapped_device *md) { return blk_queue_stackable(md->queue); } @@ -1993,6 +2013,8 @@ static struct mapped_device *alloc_dev(i md->flush_bio.bi_bdev = md->bdev; md->flush_bio.bi_rw = WRITE_FLUSH; + dm_stats_init_device(&md->stats); + /* Populate the mapping, nobody knows we exist yet */ spin_lock(&_minor_lock); old_md = idr_replace(&_minor_idr, md, minor); @@ -2046,6 +2068,7 @@ static void free_dev(struct mapped_devic put_disk(md->disk); blk_cleanup_queue(md->queue); + dm_stats_exit_device(&md->stats); module_put(THIS_MODULE); kfree(md); } @@ -2722,6 +2745,29 @@ out: return r; } +void dm_internal_suspend(struct mapped_device *md) +{ + mutex_lock(&md->suspend_lock); + if (dm_suspended_md(md)) + return; + + set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); + synchronize_srcu(&md->io_barrier); + flush_workqueue(md->wq); + dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); +} + +void dm_internal_resume(struct mapped_device *md) +{ + if (dm_suspended_md(md)) + goto done; + + dm_queue_flush(md); + +done: + mutex_unlock(&md->suspend_lock); +} + /*----------------------------------------------------------------- * Event notification. *---------------------------------------------------------------*/ Index: linux/drivers/md/dm.h =================================================================== --- linux.orig/drivers/md/dm.h +++ linux/drivers/md/dm.h @@ -16,6 +16,8 @@ #include #include +#include "dm-stats.h" + /* * Suspend feature flags */ @@ -146,10 +148,16 @@ void dm_destroy(struct mapped_device *md void dm_destroy_immediate(struct mapped_device *md); int dm_open_count(struct mapped_device *md); int dm_lock_for_deletion(struct mapped_device *md); +int dm_request_based(struct mapped_device *md); +sector_t dm_get_size(struct mapped_device *md); +struct dm_stats *dm_get_stats(struct mapped_device *md); int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, unsigned cookie); +void dm_internal_suspend(struct mapped_device *md); +void dm_internal_resume(struct mapped_device *md); + int dm_io_init(void); void dm_io_exit(void); Index: linux/include/uapi/linux/dm-ioctl.h =================================================================== --- linux.orig/include/uapi/linux/dm-ioctl.h +++ linux/include/uapi/linux/dm-ioctl.h @@ -336,4 +336,9 @@ enum { */ #define DM_SECURE_DATA_FLAG (1 << 15) /* In */ +/* + * If set, message generated output. + */ +#define DM_MESSAGE_OUT_FLAG (1 << 16) /* Out */ + #endif /* _LINUX_DM_IOCTL_H */