diff options
| -rw-r--r-- | drivers/md/dm-log-userspace-base.c | 206 | ||||
| -rw-r--r-- | include/uapi/linux/dm-log-userspace.h | 20 |
2 files changed, 176 insertions, 50 deletions
diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c index 9429159d9ee..b953db6cc22 100644 --- a/drivers/md/dm-log-userspace-base.c +++ b/drivers/md/dm-log-userspace-base.c @@ -10,10 +10,11 @@ #include <linux/device-mapper.h> #include <linux/dm-log-userspace.h> #include <linux/module.h> +#include <linux/workqueue.h> #include "dm-log-userspace-transfer.h" -#define DM_LOG_USERSPACE_VSN "1.1.0" +#define DM_LOG_USERSPACE_VSN "1.3.0" struct flush_entry { int type; @@ -58,6 +59,18 @@ struct log_c { spinlock_t flush_lock; struct list_head mark_list; struct list_head clear_list; + + /* + * Workqueue for flush of clear region requests. + */ + struct workqueue_struct *dmlog_wq; + struct delayed_work flush_log_work; + atomic_t sched_flush; + + /* + * Combine userspace flush and mark requests for efficiency. + */ + uint32_t integrated_flush; }; static mempool_t *flush_entry_pool; @@ -122,6 +135,9 @@ static int build_constructor_string(struct dm_target *ti, *ctr_str = NULL; + /* + * Determine overall size of the string. + */ for (i = 0, str_size = 0; i < argc; i++) str_size += strlen(argv[i]) + 1; /* +1 for space between args */ @@ -141,18 +157,39 @@ static int build_constructor_string(struct dm_target *ti, return str_size; } +static void do_flush(struct work_struct *work) +{ + int r; + struct log_c *lc = container_of(work, struct log_c, flush_log_work.work); + + atomic_set(&lc->sched_flush, 0); + + r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, NULL, 0, NULL, NULL); + + if (r) + dm_table_event(lc->ti->table); +} + /* * userspace_ctr * * argv contains: - * <UUID> <other args> - * Where 'other args' is the userspace implementation specific log - * arguments. An example might be: - * <UUID> clustered-disk <arg count> <log dev> <region_size> [[no]sync] + * <UUID> [integrated_flush] <other args> + * Where 'other args' are the userspace implementation-specific log + * arguments. + * + * Example: + * <UUID> [integrated_flush] clustered-disk <arg count> <log dev> + * <region_size> [[no]sync] + * + * This module strips off the <UUID> and uses it for identification + * purposes when communicating with userspace about a log. * - * So, this module will strip off the <UUID> for identification purposes - * when communicating with userspace about a log; but will pass on everything - * else. + * If integrated_flush is defined, the kernel combines flush + * and mark requests. + * + * The rest of the line, beginning with 'clustered-disk', is passed + * to the userspace ctr function. */ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, unsigned argc, char **argv) @@ -188,12 +225,22 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, return -EINVAL; } + lc->usr_argc = argc; + strncpy(lc->uuid, argv[0], DM_UUID_LEN); + argc--; + argv++; spin_lock_init(&lc->flush_lock); INIT_LIST_HEAD(&lc->mark_list); INIT_LIST_HEAD(&lc->clear_list); - str_size = build_constructor_string(ti, argc - 1, argv + 1, &ctr_str); + if (!strcasecmp(argv[0], "integrated_flush")) { + lc->integrated_flush = 1; + argc--; + argv++; + } + + str_size = build_constructor_string(ti, argc, argv, &ctr_str); if (str_size < 0) { kfree(lc); return str_size; @@ -246,6 +293,19 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, DMERR("Failed to register %s with device-mapper", devices_rdata); } + + if (lc->integrated_flush) { + lc->dmlog_wq = alloc_workqueue("dmlogd", WQ_MEM_RECLAIM, 0); + if (!lc->dmlog_wq) { + DMERR("couldn't start dmlogd"); + r = -ENOMEM; + goto out; + } + + INIT_DELAYED_WORK(&lc->flush_log_work, do_flush); + atomic_set(&lc->sched_flush, 0); + } + out: kfree(devices_rdata); if (r) { @@ -253,7 +313,6 @@ out: kfree(ctr_str); } else { lc->usr_argv_str = ctr_str; - lc->usr_argc = argc; log->context = lc; } @@ -264,9 +323,16 @@ static void userspace_dtr(struct dm_dirty_log *log) { struct log_c *lc = log->context; + if (lc->integrated_flush) { + /* flush workqueue */ + if (atomic_read(&lc->sched_flush)) + flush_delayed_work(&lc->flush_log_work); + + destroy_workqueue(lc->dmlog_wq); + } + (void) dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR, - NULL, 0, - NULL, NULL); + NULL, 0, NULL, NULL); if (lc->log_dev) dm_put_device(lc->ti, lc->log_dev); @@ -283,8 +349,7 @@ static int userspace_presuspend(struct dm_dirty_log *log) struct log_c *lc = log->context; r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_PRESUSPEND, - NULL, 0, - NULL, NULL); + NULL, 0, NULL, NULL); return r; } @@ -294,9 +359,14 @@ static int userspace_postsuspend(struct dm_dirty_log *log) int r; struct log_c *lc = log->context; + /* + * Run planned flush earlier. + */ + if (lc->integrated_flush && atomic_read(&lc->sched_flush)) + flush_delayed_work(&lc->flush_log_work); + r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_POSTSUSPEND, - NULL, 0, - NULL, NULL); + NULL, 0, NULL, NULL); return r; } @@ -308,8 +378,7 @@ static int userspace_resume(struct dm_dirty_log *log) lc->in_sync_hint = 0; r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_RESUME, - NULL, 0, - NULL, NULL); + NULL, 0, NULL, NULL); return r; } @@ -405,7 +474,8 @@ static int flush_one_by_one(struct log_c *lc, struct list_head *flush_list) return r; } -static int flush_by_group(struct log_c *lc, struct list_head *flush_list) +static int flush_by_group(struct log_c *lc, struct list_head *flush_list, + int flush_with_payload) { int r = 0; int count; @@ -431,15 +501,29 @@ static int flush_by_group(struct log_c *lc, struct list_head *flush_list) break; } - r = userspace_do_request(lc, lc->uuid, type, - (char *)(group), - count * sizeof(uint64_t), - NULL, NULL); - if (r) { - /* Group send failed. Attempt one-by-one. */ - list_splice_init(&tmp_list, flush_list); - r = flush_one_by_one(lc, flush_list); - break; + if (flush_with_payload) { + r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, + (char *)(group), + count * sizeof(uint64_t), + NULL, NULL); + /* + * Integrated flush failed. + */ + if (r) + break; + } else { + r = userspace_do_request(lc, lc->uuid, type, + (char *)(group), + count * sizeof(uint64_t), + NULL, NULL); + if (r) { + /* + * Group send failed. Attempt one-by-one. + */ + list_splice_init(&tmp_list, flush_list); + r = flush_one_by_one(lc, flush_list); + break; + } } } @@ -476,6 +560,8 @@ static int userspace_flush(struct dm_dirty_log *log) struct log_c *lc = log->context; LIST_HEAD(mark_list); LIST_HEAD(clear_list); + int mark_list_is_empty; + int clear_list_is_empty; struct flush_entry *fe, *tmp_fe; spin_lock_irqsave(&lc->flush_lock, flags); @@ -483,23 +569,51 @@ static int userspace_flush(struct dm_dirty_log *log) list_splice_init(&lc->clear_list, &clear_list); spin_unlock_irqrestore(&lc->flush_lock, flags); - if (list_empty(&mark_list) && list_empty(&clear_list)) + mark_list_is_empty = list_empty(&mark_list); + clear_list_is_empty = list_empty(&clear_list); + + if (mark_list_is_empty && clear_list_is_empty) return 0; - r = flush_by_group(lc, &mark_list); + r = flush_by_group(lc, &clear_list, 0); if (r) - goto fail; + goto out; - r = flush_by_group(lc, &clear_list); + if (!lc->integrated_flush) { + r = flush_by_group(lc, &mark_list, 0); + if (r) + goto out; + r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, + NULL, 0, NULL, NULL); + goto out; + } + + /* + * Send integrated flush request with mark_list as payload. + */ + r = flush_by_group(lc, &mark_list, 1); if (r) - goto fail; + goto out; - r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, - NULL, 0, NULL, NULL); + if (mark_list_is_empty && !atomic_read(&lc->sched_flush)) { + /* + * When there are only clear region requests, + * we schedule a flush in the future. + */ + queue_delayed_work(lc->dmlog_wq, &lc->flush_log_work, 3 * HZ); + atomic_set(&lc->sched_flush, 1); + } else { + /* + * Cancel pending flush because we + * have already flushed in mark_region. + */ + cancel_delayed_work(&lc->flush_log_work); + atomic_set(&lc->sched_flush, 0); + } -fail: +out: /* - * We can safely remove these entries, even if failure. + * We can safely remove these entries, even after failure. * Calling code will receive an error and will know that * the log facility has failed. */ @@ -603,8 +717,7 @@ static int userspace_get_resync_work(struct dm_dirty_log *log, region_t *region) rdata_size = sizeof(pkg); r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_RESYNC_WORK, - NULL, 0, - (char *)&pkg, &rdata_size); + NULL, 0, (char *)&pkg, &rdata_size); *region = pkg.r; return (r) ? r : (int)pkg.i; @@ -630,8 +743,7 @@ static void userspace_set_region_sync(struct dm_dirty_log *log, pkg.i = (int64_t)in_sync; r = userspace_do_request(lc, lc->uuid, DM_ULOG_SET_REGION_SYNC, - (char *)&pkg, sizeof(pkg), - NULL, NULL); + (char *)&pkg, sizeof(pkg), NULL, NULL); /* * It would be nice to be able to report failures. @@ -657,8 +769,7 @@ static region_t userspace_get_sync_count(struct dm_dirty_log *log) rdata_size = sizeof(sync_count); r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_SYNC_COUNT, - NULL, 0, - (char *)&sync_count, &rdata_size); + NULL, 0, (char *)&sync_count, &rdata_size); if (r) return 0; @@ -685,8 +796,7 @@ static int userspace_status(struct dm_dirty_log *log, status_type_t status_type, switch (status_type) { case STATUSTYPE_INFO: r = userspace_do_request(lc, lc->uuid, DM_ULOG_STATUS_INFO, - NULL, 0, - result, &sz); + NULL, 0, result, &sz); if (r) { sz = 0; @@ -699,8 +809,10 @@ static int userspace_status(struct dm_dirty_log *log, status_type_t status_type, BUG_ON(!table_args); /* There will always be a ' ' */ table_args++; - DMEMIT("%s %u %s %s ", log->type->name, lc->usr_argc, - lc->uuid, table_args); + DMEMIT("%s %u %s ", log->type->name, lc->usr_argc, lc->uuid); + if (lc->integrated_flush) + DMEMIT("integrated_flush "); + DMEMIT("%s ", table_args); break; } return (r) ? 0 : (int)sz; diff --git a/include/uapi/linux/dm-log-userspace.h b/include/uapi/linux/dm-log-userspace.h index 0678c2adc42..0fa0d9ef06a 100644 --- a/include/uapi/linux/dm-log-userspace.h +++ b/include/uapi/linux/dm-log-userspace.h @@ -201,11 +201,18 @@ * int (*flush)(struct dm_dirty_log *log); * * Payload-to-userspace: - * None. + * If the 'integrated_flush' directive is present in the constructor + * table, the payload is as same as DM_ULOG_MARK_REGION: + * uint64_t [] - region(s) to mark + * else + * None * Payload-to-kernel: * None. * - * No incoming or outgoing payload. Simply flush log state to disk. + * If the 'integrated_flush' option was used during the creation of the + * log, mark region requests are carried as payload in the flush request. + * Piggybacking the mark requests in this way allows for fewer communications + * between kernel and userspace. * * When the request has been processed, user-space must return the * dm_ulog_request to the kernel - setting the 'error' field and clearing @@ -385,8 +392,15 @@ * version 2: DM_ULOG_CTR allowed to return a string containing a * device name that is to be registered with DM via * 'dm_get_device'. + * version 3: DM_ULOG_FLUSH is capable of carrying payload for marking + * regions. This "integrated flush" reduces the number of + * requests between the kernel and userspace by effectively + * merging 'mark' and 'flush' requests. A constructor table + * argument ('integrated_flush') is required to turn this + * feature on, so it is backwards compatible with older + * userspace versions. */ -#define DM_ULOG_REQUEST_VERSION 2 +#define DM_ULOG_REQUEST_VERSION 3 struct dm_ulog_request { /* |