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author | David S. Miller <davem@davemloft.net> | 2010-03-15 23:23:54 (GMT) |
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committer | David S. Miller <davem@davemloft.net> | 2010-03-15 23:23:54 (GMT) |
commit | 4961e02f1999e1c3468c09b2669c94d7c3ae82a8 (patch) | |
tree | 44c15abb09d7ba5e17a9aba95ee246648b1c1a8a /drivers/md/dm-mpath.c | |
parent | d14a0ebda7d3daede1a99c01527affb9ceaa4c22 (diff) | |
parent | a3d3203e4bb40f253b1541e310dc0f9305be7c84 (diff) | |
download | linux-fsl-qoriq-4961e02f1999e1c3468c09b2669c94d7c3ae82a8.tar.xz |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Diffstat (limited to 'drivers/md/dm-mpath.c')
-rw-r--r-- | drivers/md/dm-mpath.c | 111 |
1 files changed, 72 insertions, 39 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index e81345a..826bce7 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -69,6 +69,7 @@ struct multipath { struct list_head priority_groups; unsigned pg_init_required; /* pg_init needs calling? */ unsigned pg_init_in_progress; /* Only one pg_init allowed at once */ + wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */ unsigned nr_valid_paths; /* Total number of usable paths */ struct pgpath *current_pgpath; @@ -95,8 +96,6 @@ struct multipath { mempool_t *mpio_pool; struct mutex work_mutex; - - unsigned suspended; /* Don't create new I/O internally when set. */ }; /* @@ -202,6 +201,7 @@ static struct multipath *alloc_multipath(struct dm_target *ti) m->queue_io = 1; INIT_WORK(&m->process_queued_ios, process_queued_ios); INIT_WORK(&m->trigger_event, trigger_event); + init_waitqueue_head(&m->pg_init_wait); mutex_init(&m->work_mutex); m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache); if (!m->mpio_pool) { @@ -235,6 +235,21 @@ static void free_multipath(struct multipath *m) * Path selection *-----------------------------------------------*/ +static void __pg_init_all_paths(struct multipath *m) +{ + struct pgpath *pgpath; + + m->pg_init_count++; + m->pg_init_required = 0; + list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) { + /* Skip failed paths */ + if (!pgpath->is_active) + continue; + if (queue_work(kmpath_handlerd, &pgpath->activate_path)) + m->pg_init_in_progress++; + } +} + static void __switch_pg(struct multipath *m, struct pgpath *pgpath) { m->current_pg = pgpath->pg; @@ -439,7 +454,7 @@ static void process_queued_ios(struct work_struct *work) { struct multipath *m = container_of(work, struct multipath, process_queued_ios); - struct pgpath *pgpath = NULL, *tmp; + struct pgpath *pgpath = NULL; unsigned must_queue = 1; unsigned long flags; @@ -457,14 +472,9 @@ static void process_queued_ios(struct work_struct *work) (!pgpath && !m->queue_if_no_path)) must_queue = 0; - if (m->pg_init_required && !m->pg_init_in_progress && pgpath) { - m->pg_init_count++; - m->pg_init_required = 0; - list_for_each_entry(tmp, &pgpath->pg->pgpaths, list) { - if (queue_work(kmpath_handlerd, &tmp->activate_path)) - m->pg_init_in_progress++; - } - } + if (m->pg_init_required && !m->pg_init_in_progress && pgpath) + __pg_init_all_paths(m); + out: spin_unlock_irqrestore(&m->lock, flags); if (!must_queue) @@ -597,8 +607,8 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps, if (!p) return ERR_PTR(-ENOMEM); - r = dm_get_device(ti, shift(as), ti->begin, ti->len, - dm_table_get_mode(ti->table), &p->path.dev); + r = dm_get_device(ti, shift(as), dm_table_get_mode(ti->table), + &p->path.dev); if (r) { ti->error = "error getting device"; goto bad; @@ -890,9 +900,34 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc, return r; } -static void flush_multipath_work(void) +static void multipath_wait_for_pg_init_completion(struct multipath *m) +{ + DECLARE_WAITQUEUE(wait, current); + unsigned long flags; + + add_wait_queue(&m->pg_init_wait, &wait); + + while (1) { + set_current_state(TASK_UNINTERRUPTIBLE); + + spin_lock_irqsave(&m->lock, flags); + if (!m->pg_init_in_progress) { + spin_unlock_irqrestore(&m->lock, flags); + break; + } + spin_unlock_irqrestore(&m->lock, flags); + + io_schedule(); + } + set_current_state(TASK_RUNNING); + + remove_wait_queue(&m->pg_init_wait, &wait); +} + +static void flush_multipath_work(struct multipath *m) { flush_workqueue(kmpath_handlerd); + multipath_wait_for_pg_init_completion(m); flush_workqueue(kmultipathd); flush_scheduled_work(); } @@ -901,7 +936,7 @@ static void multipath_dtr(struct dm_target *ti) { struct multipath *m = ti->private; - flush_multipath_work(); + flush_multipath_work(m); free_multipath(m); } @@ -1128,8 +1163,7 @@ static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) static void pg_init_done(void *data, int errors) { - struct dm_path *path = data; - struct pgpath *pgpath = path_to_pgpath(path); + struct pgpath *pgpath = data; struct priority_group *pg = pgpath->pg; struct multipath *m = pg->m; unsigned long flags; @@ -1143,8 +1177,8 @@ static void pg_init_done(void *data, int errors) errors = 0; break; } - DMERR("Cannot failover device because scsi_dh_%s was not " - "loaded.", m->hw_handler_name); + DMERR("Could not failover the device: Handler scsi_dh_%s " + "Error %d.", m->hw_handler_name, errors); /* * Fail path for now, so we do not ping pong */ @@ -1181,14 +1215,24 @@ static void pg_init_done(void *data, int errors) m->current_pgpath = NULL; m->current_pg = NULL; } - } else if (!m->pg_init_required) { - m->queue_io = 0; + } else if (!m->pg_init_required) pg->bypassed = 0; - } - m->pg_init_in_progress--; - if (!m->pg_init_in_progress) - queue_work(kmultipathd, &m->process_queued_ios); + if (--m->pg_init_in_progress) + /* Activations of other paths are still on going */ + goto out; + + if (!m->pg_init_required) + m->queue_io = 0; + + queue_work(kmultipathd, &m->process_queued_ios); + + /* + * Wake up any thread waiting to suspend. + */ + wake_up(&m->pg_init_wait); + +out: spin_unlock_irqrestore(&m->lock, flags); } @@ -1198,7 +1242,7 @@ static void activate_path(struct work_struct *work) container_of(work, struct pgpath, activate_path); scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), - pg_init_done, &pgpath->path); + pg_init_done, pgpath); } /* @@ -1276,8 +1320,7 @@ static void multipath_postsuspend(struct dm_target *ti) struct multipath *m = ti->private; mutex_lock(&m->work_mutex); - m->suspended = 1; - flush_multipath_work(); + flush_multipath_work(m); mutex_unlock(&m->work_mutex); } @@ -1289,10 +1332,6 @@ static void multipath_resume(struct dm_target *ti) struct multipath *m = (struct multipath *) ti->private; unsigned long flags; - mutex_lock(&m->work_mutex); - m->suspended = 0; - mutex_unlock(&m->work_mutex); - spin_lock_irqsave(&m->lock, flags); m->queue_if_no_path = m->saved_queue_if_no_path; spin_unlock_irqrestore(&m->lock, flags); @@ -1428,11 +1467,6 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) mutex_lock(&m->work_mutex); - if (m->suspended) { - r = -EBUSY; - goto out; - } - if (dm_suspended(ti)) { r = -EBUSY; goto out; @@ -1471,8 +1505,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) goto out; } - r = dm_get_device(ti, argv[1], ti->begin, ti->len, - dm_table_get_mode(ti->table), &dev); + r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev); if (r) { DMWARN("message: error getting device %s", argv[1]); |