diff options
| -rw-r--r-- | drivers/md/dm-mpath.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 97c095220c79..2bc18c9c3abc 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -20,6 +20,7 @@ #include <linux/pagemap.h> #include <linux/slab.h> #include <linux/time.h> +#include <linux/timer.h> #include <linux/workqueue.h> #include <linux/delay.h> #include <scsi/scsi_dh.h> @@ -29,6 +30,9 @@ #define DM_MSG_PREFIX "multipath" #define DM_PG_INIT_DELAY_MSECS 2000 #define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1) +#define QUEUE_IF_NO_PATH_TIMEOUT_DEFAULT 0 + +static unsigned long queue_if_no_path_timeout_secs = QUEUE_IF_NO_PATH_TIMEOUT_DEFAULT; /* Path properties */ struct pgpath { @@ -91,6 +95,8 @@ struct multipath { struct work_struct process_queued_bios; struct bio_list queued_bios; + + struct timer_list nopath_timer; /* Timeout for queue_if_no_path */ }; /* @@ -108,6 +114,7 @@ static void trigger_event(struct work_struct *work); static void activate_or_offline_path(struct pgpath *pgpath); static void activate_path_work(struct work_struct *work); static void process_queued_bios(struct work_struct *work); +static void queue_if_no_path_timeout_work(struct timer_list *t); /*----------------------------------------------- * Multipath state flags. @@ -195,6 +202,8 @@ static struct multipath *alloc_multipath(struct dm_target *ti) m->ti = ti; ti->private = m; + + timer_setup(&m->nopath_timer, queue_if_no_path_timeout_work, 0); } return m; @@ -718,6 +727,43 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path, } /* + * If the queue_if_no_path timeout fires, turn off queue_if_no_path and + * process any queued I/O. + */ +static void queue_if_no_path_timeout_work(struct timer_list *t) +{ + struct multipath *m = from_timer(m, t, nopath_timer); + struct mapped_device *md = dm_table_get_md(m->ti->table); + + DMWARN("queue_if_no_path timeout on %s, failing queued IO", dm_device_name(md)); + queue_if_no_path(m, false, false); +} + +/* + * Enable the queue_if_no_path timeout if necessary. + * Called with m->lock held. + */ +static void enable_nopath_timeout(struct multipath *m) +{ + unsigned long queue_if_no_path_timeout = + READ_ONCE(queue_if_no_path_timeout_secs) * HZ; + + lockdep_assert_held(&m->lock); + + if (queue_if_no_path_timeout > 0 && + atomic_read(&m->nr_valid_paths) == 0 && + test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { + mod_timer(&m->nopath_timer, + jiffies + queue_if_no_path_timeout); + } +} + +static void disable_nopath_timeout(struct multipath *m) +{ + del_timer_sync(&m->nopath_timer); +} + +/* * An event is triggered whenever a path is taken out of use. * Includes path failure and PG bypass. */ @@ -1090,6 +1136,7 @@ static int multipath_ctr(struct dm_target *ti, unsigned argc, char **argv) struct dm_arg_set as; unsigned pg_count = 0; unsigned next_pg_num; + unsigned long flags; as.argc = argc; as.argv = argv; @@ -1154,6 +1201,10 @@ static int multipath_ctr(struct dm_target *ti, unsigned argc, char **argv) goto bad; } + spin_lock_irqsave(&m->lock, flags); + enable_nopath_timeout(m); + spin_unlock_irqrestore(&m->lock, flags); + ti->num_flush_bios = 1; ti->num_discard_bios = 1; ti->num_write_same_bios = 1; @@ -1208,6 +1259,7 @@ static void multipath_dtr(struct dm_target *ti) { struct multipath *m = ti->private; + disable_nopath_timeout(m); flush_multipath_work(m); free_multipath(m); } @@ -1241,6 +1293,8 @@ static int fail_path(struct pgpath *pgpath) schedule_work(&m->trigger_event); + enable_nopath_timeout(m); + out: spin_unlock_irqrestore(&m->lock, flags); @@ -1291,6 +1345,9 @@ out: process_queued_io_list(m); } + if (pgpath->is_active) + disable_nopath_timeout(m); + return r; } @@ -1789,6 +1846,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv, struct dm_dev *dev; struct multipath *m = ti->private; action_fn action; + unsigned long flags; mutex_lock(&m->work_mutex); @@ -1800,9 +1858,13 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv, if (argc == 1) { if (!strcasecmp(argv[0], "queue_if_no_path")) { r = queue_if_no_path(m, true, false); + spin_lock_irqsave(&m->lock, flags); + enable_nopath_timeout(m); + spin_unlock_irqrestore(&m->lock, flags); goto out; } else if (!strcasecmp(argv[0], "fail_if_no_path")) { r = queue_if_no_path(m, false, false); + disable_nopath_timeout(m); goto out; } } @@ -2065,6 +2127,10 @@ static void __exit dm_multipath_exit(void) module_init(dm_multipath_init); module_exit(dm_multipath_exit); +module_param_named(queue_if_no_path_timeout_secs, + queue_if_no_path_timeout_secs, ulong, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(queue_if_no_path_timeout_secs, "No available paths queue IO timeout in seconds"); + MODULE_DESCRIPTION(DM_NAME " multipath target"); MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); MODULE_LICENSE("GPL"); |