[RFC,v3] dm mpath: add a queue_if_no_path timeout

Message ID	1383667332.4504.8.camel@bobble.lax.corp.google.com (mailing list archive)
State	Rejected, archived
Delegated to:	Mike Snitzer
Headers	show Return-Path: <dm-devel-bounces@redhat.com> Message-ID: <1383667332.4504.8.camel@bobble.lax.corp.google.com> From: Frank Mayhar <fmayhar@google.com> To: Junichi Nomura <j-nomura@ce.jp.nec.com> Date: Tue, 05 Nov 2013 08:02:12 -0800 In-Reply-To: <1383664708.4504.4.camel@bobble.lax.corp.google.com> References: <20130926232241.GC31328@agk-dp.fab.redhat.com> <20130926234957.GA3658@redhat.com> <1382036590.1980.32.camel@bobble.lax.corp.google.com> <20131017191511.GA30452@redhat.com> <1382042759.1980.40.camel@bobble.lax.corp.google.com> <20131017211338.GB30993@redhat.com> <1382129515.1980.46.camel@bobble.lax.corp.google.com> <20131018225350.GB7553@redhat.com> <20131030010246.GA3611@redhat.com> <1383145687.6677.49.camel@bobble.lax.corp.google.com> <20131030154259.GA8206@redhat.com> <1383156565.17572.8.camel@bobble.lax.corp.google.com> <11AF7C027C4C02408624617A49860784EDC2C1@BPXM12GP.gisp.nec.co.jp> <1383229011.17572.12.camel@bobble.lax.corp.google.com> <11AF7C027C4C02408624617A49860784EE0B3F@BPXM12GP.gisp.nec.co.jp> <11AF7C027C4C02408624617A49860784EE0F5E@BPXM12GP.gisp.nec.co.jp> <1383664708.4504.4.camel@bobble.lax.corp.google.com> Mime-Version: 1.0 Cc: device-mapper development <dm-devel@redhat.com>, Mike Snitzer <snitzer@redhat.com>, "Alasdair G. Kergon" <agk@redhat.com> Subject: [dm-devel] [RFC PATCH v3] dm mpath: add a queue_if_no_path timeout Precedence: junk Reply-To: device-mapper development <dm-devel@redhat.com> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com

diff --git a/block/blk-timeout.c b/block/blk-timeout.c index 65f1035..7ea06b0 100644 --- a/block/blk-timeout.c +++ b/block/blk-timeout.c @@ -170,7 +170,7 @@ void blk_add_timer(struct request *req) struct request_queue *q = req->q; unsigned long expiry; - if (!q->rq_timed_out_fn) + if (!q->rq_timed_out_fn || !q->rq_timeout) return; BUG_ON(!list_empty(&req->timeout_list)); diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index de570a5..6f127b7 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -27,6 +27,8 @@ #define DM_PG_INIT_DELAY_MSECS 2000 #define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1) +#define DEFAULT_NO_PATH_TIMEOUT_SECS 0 + /* Path properties */ struct pgpath { struct list_head list; @@ -105,6 +107,8 @@ struct multipath { mempool_t *mpio_pool; struct mutex work_mutex; + + unsigned no_path_timeout; }; /* @@ -117,6 +121,10 @@ struct dm_mpath_io { typedef int (*action_fn) (struct pgpath *pgpath); +static unsigned long global_no_path_timeout = DEFAULT_NO_PATH_TIMEOUT_SECS; +module_param_named(queue_if_no_path_timeout_secs, + global_no_path_timeout, ulong, S_IRUGO | S_IWUSR); + static struct kmem_cache *_mpio_cache; static struct workqueue_struct *kmultipathd, *kmpath_handlerd; @@ -207,6 +215,7 @@ static struct multipath *alloc_multipath(struct dm_target *ti) kfree(m); return NULL; } + m->no_path_timeout = global_no_path_timeout; m->ti = ti; ti->private = m; } @@ -444,6 +453,45 @@ static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, return 0; } +/* + * Block timeout callback, called from the block layer + * + * request_queue lock is held on entry. + * + * Return values: + * BLK_EH_RESET_TIMER if the request should be left running + * BLK_EH_NOT_HANDLED if the request is handled or terminated + * by the driver. + */ +enum blk_eh_timer_return multipath_timed_out(struct dm_target *ti, + struct request *clone) +{ + unsigned long flags; + struct multipath *m = ti->private; + int rc = BLK_EH_RESET_TIMER; + int flush_ios = 0; + + /* + * Only abort request if: + * - queued_ios is not empty + * (protect against races with process_queued_ios) + * - no valid paths are found + */ + spin_lock_irqsave(&m->lock, flags); + if (m->no_path_timeout && + !list_empty(&m->queued_ios) && !m->nr_valid_paths) { + flush_ios = 1; + } + spin_unlock_irqrestore(&m->lock, flags); + + if (flush_ios) { + queue_if_no_path(m, 0, 0); + queue_work(kmultipathd, &m->process_queued_ios); + } + + return rc; +} + /*----------------------------------------------------------------- * The multipath daemon is responsible for resubmitting queued ios. *---------------------------------------------------------------*/ @@ -790,6 +838,7 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m) {0, 6, "invalid number of feature args"}, {1, 50, "pg_init_retries must be between 1 and 50"}, {0, 60000, "pg_init_delay_msecs must be between 0 and 60000"}, + {0, 65535, "queue_if_no_path_timeout_secs must be between 0 and 65535"}, }; r = dm_read_arg_group(_args, as, &argc, &ti->error); @@ -827,6 +876,13 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m) continue; } + if (!strcasecmp(arg_name, "queue_if_no_path_timeout_secs") && + (argc >= 1)) { + r = dm_read_arg(_args + 3, as, &m->no_path_timeout, &ti->error); + argc--; + continue; + } + ti->error = "Unrecognised multipath feature request"; r = -EINVAL; } while (argc && !r); @@ -978,6 +1034,27 @@ static int multipath_map(struct dm_target *ti, struct request *clone, } /* + * Set the no_path_timeout on behalf of a message. Note that this only + * affects new requests; already-queued requests are unaffected. + */ +static int set_no_path_timeout(struct multipath *m, const char *timestr) +{ + unsigned long to; + unsigned long flags; + + if (!timestr || (sscanf(timestr, "%lu", &to) != 1)) { + DMWARN("invalid timeout supplied to set_no_path_timeout"); + return -EINVAL; + } + + spin_lock_irqsave(&m->lock, flags); + m->no_path_timeout = to; + dm_set_timeout(dm_table_get_md(m->ti->table), m->no_path_timeout); + spin_unlock_irqrestore(&m->lock, flags); + return 0; +} + +/* * Take a path out of use. */ static int fail_path(struct pgpath *pgpath) @@ -1384,6 +1461,7 @@ static void multipath_resume(struct dm_target *ti) spin_lock_irqsave(&m->lock, flags); m->queue_if_no_path = m->saved_queue_if_no_path; + dm_set_timeout(dm_table_get_md(m->ti->table), m->no_path_timeout); spin_unlock_irqrestore(&m->lock, flags); } @@ -1421,11 +1499,14 @@ static void multipath_status(struct dm_target *ti, status_type_t type, DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count); else { DMEMIT("%u ", m->queue_if_no_path + + (m->no_path_timeout > 0) * 2 + (m->pg_init_retries > 0) * 2 + (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 + m->retain_attached_hw_handler); if (m->queue_if_no_path) DMEMIT("queue_if_no_path "); + if (m->no_path_timeout) + DMEMIT("queue_if_no_path_timeout_secs %u ", m->no_path_timeout); if (m->pg_init_retries) DMEMIT("pg_init_retries %u ", m->pg_init_retries); if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) @@ -1550,6 +1631,9 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) } else if (!strcasecmp(argv[0], "switch_group")) { r = switch_pg_num(m, argv[1]); goto out; + } else if (!strcasecmp(argv[0], "queue_if_no_path_timeout_secs")) { + r = set_no_path_timeout(m, argv[1]); + goto out; } else if (!strcasecmp(argv[0], "reinstate_path")) action = reinstate_path; else if (!strcasecmp(argv[0], "fail_path")) @@ -1728,6 +1812,7 @@ static struct target_type multipath_target = { .ioctl = multipath_ioctl, .iterate_devices = multipath_iterate_devices, .busy = multipath_busy, + .timed_out = multipath_timed_out, }; static int __init dm_multipath_init(void) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 8f87835..32c5399 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -26,6 +26,8 @@ #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t)) #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1) +enum blk_eh_timer_return dm_rq_timed_out(struct request *rq); + struct dm_table { struct mapped_device *md; unsigned type; @@ -1519,6 +1521,7 @@ static void suspend_targets(struct dm_table *t, unsigned postsuspend) ti++; } + blk_queue_rq_timed_out(dm_disk(t->md)->queue, NULL); } void dm_table_presuspend_targets(struct dm_table *t) @@ -1540,10 +1543,14 @@ void dm_table_postsuspend_targets(struct dm_table *t) int dm_table_resume_targets(struct dm_table *t) { int i, r = 0; + int has_timeout = 0; for (i = 0; i < t->num_targets; i++) { struct dm_target *ti = t->targets + i; + if (ti->type->timed_out) + has_timeout = 1; + if (!ti->type->preresume) continue; @@ -1552,6 +1559,9 @@ int dm_table_resume_targets(struct dm_table *t) return r; } + if (has_timeout) + blk_queue_rq_timed_out(dm_disk(t->md)->queue, dm_rq_timed_out); + for (i = 0; i < t->num_targets; i++) { struct dm_target *ti = t->targets + i; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index b3e26c7..bb7a29c 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1026,6 +1026,13 @@ static void end_clone_request(struct request *clone, int error) dm_complete_request(clone, error); } +int dm_set_timeout(struct mapped_device *md, unsigned int tmo) +{ + blk_queue_rq_timeout(md->queue, tmo * HZ); + return 0; +} +EXPORT_SYMBOL_GPL(dm_set_timeout); + /* * Return maximum size of I/O possible at the supplied sector up to the current * target boundary. @@ -1829,6 +1836,21 @@ out: dm_put_live_table(md, srcu_idx); } +enum blk_eh_timer_return dm_rq_timed_out(struct request *rq) +{ + struct request *clone = rq->special; + struct dm_rq_target_io *tio = clone->end_io_data; + + if (!tio) + goto out; /* not mapped */ + + if (tio->ti->type->timed_out) + return tio->ti->type->timed_out(tio->ti, clone); + +out: + return BLK_EH_RESET_TIMER; +} + int dm_underlying_device_busy(struct request_queue *q) { return blk_lld_busy(q); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index ed419c6..84c0368 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -107,6 +107,8 @@ typedef int (*dm_iterate_devices_fn) (struct dm_target *ti, typedef void (*dm_io_hints_fn) (struct dm_target *ti, struct queue_limits *limits); +typedef enum blk_eh_timer_return (*dm_rq_timed_out_fn) (struct dm_target *ti, + struct request *clone); /* * Returns: * 0: The target can handle the next I/O immediately. @@ -162,6 +164,7 @@ struct target_type { dm_busy_fn busy; dm_iterate_devices_fn iterate_devices; dm_io_hints_fn io_hints; + dm_rq_timed_out_fn timed_out; /* For internal device-mapper use. */ struct list_head list; @@ -604,5 +607,6 @@ void dm_dispatch_request(struct request *rq); void dm_requeue_unmapped_request(struct request *rq); void dm_kill_unmapped_request(struct request *rq, int error); int dm_underlying_device_busy(struct request_queue *q); +int dm_set_timeout(struct mapped_device *md, unsigned int tmo); #endif /* _LINUX_DEVICE_MAPPER_H */

[RFC,v3] dm mpath: add a queue_if_no_path timeout

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