diff options
Diffstat (limited to 'drivers/md/dm-mpath.c')
| -rw-r--r-- | drivers/md/dm-mpath.c | 344 |
1 files changed, 177 insertions, 167 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 638dae048b4..f4167b013d9 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -7,6 +7,7 @@ #include <linux/device-mapper.h> +#include "dm.h" #include "dm-path-selector.h" #include "dm-uevent.h" @@ -85,15 +86,13 @@ struct multipath { unsigned queue_io:1; /* Must we queue all I/O? */ unsigned queue_if_no_path:1; /* Queue I/O if last path fails? */ unsigned saved_queue_if_no_path:1; /* Saved state during suspension */ + unsigned retain_attached_hw_handler:1; /* If there's already a hw_handler present, don't change it. */ + unsigned pg_init_disabled:1; /* pg_init is not currently allowed */ unsigned pg_init_retries; /* Number of times to retry pg_init */ unsigned pg_init_count; /* Number of times pg_init called */ unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */ - unsigned queue_size; - struct work_struct process_queued_ios; - struct list_head queued_ios; - struct work_struct trigger_event; /* @@ -115,14 +114,12 @@ struct dm_mpath_io { typedef int (*action_fn) (struct pgpath *pgpath); -#define MIN_IOS 256 /* Mempool size */ - static struct kmem_cache *_mpio_cache; static struct workqueue_struct *kmultipathd, *kmpath_handlerd; -static void process_queued_ios(struct work_struct *work); static void trigger_event(struct work_struct *work); static void activate_path(struct work_struct *work); +static int __pgpath_busy(struct pgpath *pgpath); /*----------------------------------------------- @@ -189,19 +186,18 @@ static void free_priority_group(struct priority_group *pg, static struct multipath *alloc_multipath(struct dm_target *ti) { struct multipath *m; + unsigned min_ios = dm_get_reserved_rq_based_ios(); m = kzalloc(sizeof(*m), GFP_KERNEL); if (m) { INIT_LIST_HEAD(&m->priority_groups); - INIT_LIST_HEAD(&m->queued_ios); spin_lock_init(&m->lock); m->queue_io = 1; m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; - 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); + m->mpio_pool = mempool_create_slab_pool(min_ios, _mpio_cache); if (!m->mpio_pool) { kfree(m); return NULL; @@ -254,13 +250,21 @@ static void clear_mapinfo(struct multipath *m, union map_info *info) * Path selection *-----------------------------------------------*/ -static void __pg_init_all_paths(struct multipath *m) +static int __pg_init_all_paths(struct multipath *m) { struct pgpath *pgpath; unsigned long pg_init_delay = 0; + if (m->pg_init_in_progress || m->pg_init_disabled) + return 0; + m->pg_init_count++; m->pg_init_required = 0; + + /* Check here to reset pg_init_required */ + if (!m->current_pg) + return 0; + if (m->pg_init_delay_retry) pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ? m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS); @@ -272,6 +276,7 @@ static void __pg_init_all_paths(struct multipath *m) pg_init_delay)) m->pg_init_in_progress++; } + return m->pg_init_in_progress; } static void __switch_pg(struct multipath *m, struct pgpath *pgpath) @@ -363,19 +368,26 @@ failed: */ static int __must_push_back(struct multipath *m) { - return (m->queue_if_no_path != m->saved_queue_if_no_path && - dm_noflush_suspending(m->ti)); + return (m->queue_if_no_path || + (m->queue_if_no_path != m->saved_queue_if_no_path && + dm_noflush_suspending(m->ti))); } -static int map_io(struct multipath *m, struct request *clone, - union map_info *map_context, unsigned was_queued) +#define pg_ready(m) (!(m)->queue_io && !(m)->pg_init_required) + +/* + * Map cloned requests + */ +static int multipath_map(struct dm_target *ti, struct request *clone, + union map_info *map_context) { - int r = DM_MAPIO_REMAPPED; + struct multipath *m = (struct multipath *) ti->private; + int r = DM_MAPIO_REQUEUE; size_t nr_bytes = blk_rq_bytes(clone); unsigned long flags; struct pgpath *pgpath; struct block_device *bdev; - struct dm_mpath_io *mpio = map_context->ptr; + struct dm_mpath_io *mpio; spin_lock_irqsave(&m->lock, flags); @@ -386,35 +398,33 @@ static int map_io(struct multipath *m, struct request *clone, pgpath = m->current_pgpath; - if (was_queued) - m->queue_size--; - - if ((pgpath && m->queue_io) || - (!pgpath && m->queue_if_no_path)) { - /* Queue for the daemon to resubmit */ - list_add_tail(&clone->queuelist, &m->queued_ios); - m->queue_size++; - if ((m->pg_init_required && !m->pg_init_in_progress) || - !m->queue_io) - queue_work(kmultipathd, &m->process_queued_ios); - pgpath = NULL; - r = DM_MAPIO_SUBMITTED; - } else if (pgpath) { - bdev = pgpath->path.dev->bdev; - clone->q = bdev_get_queue(bdev); - clone->rq_disk = bdev->bd_disk; - } else if (__must_push_back(m)) - r = DM_MAPIO_REQUEUE; - else - r = -EIO; /* Failed */ + if (!pgpath) { + if (!__must_push_back(m)) + r = -EIO; /* Failed */ + goto out_unlock; + } + if (!pg_ready(m)) { + __pg_init_all_paths(m); + goto out_unlock; + } + if (set_mapinfo(m, map_context) < 0) + /* ENOMEM, requeue */ + goto out_unlock; + bdev = pgpath->path.dev->bdev; + clone->q = bdev_get_queue(bdev); + clone->rq_disk = bdev->bd_disk; + clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; + mpio = map_context->ptr; mpio->pgpath = pgpath; mpio->nr_bytes = nr_bytes; - - if (r == DM_MAPIO_REMAPPED && pgpath->pg->ps.type->start_io) - pgpath->pg->ps.type->start_io(&pgpath->pg->ps, &pgpath->path, + if (pgpath->pg->ps.type->start_io) + pgpath->pg->ps.type->start_io(&pgpath->pg->ps, + &pgpath->path, nr_bytes); + r = DM_MAPIO_REMAPPED; +out_unlock: spin_unlock_irqrestore(&m->lock, flags); return r; @@ -435,73 +445,12 @@ static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, else m->saved_queue_if_no_path = queue_if_no_path; m->queue_if_no_path = queue_if_no_path; - if (!m->queue_if_no_path && m->queue_size) - queue_work(kmultipathd, &m->process_queued_ios); - spin_unlock_irqrestore(&m->lock, flags); - return 0; -} - -/*----------------------------------------------------------------- - * The multipath daemon is responsible for resubmitting queued ios. - *---------------------------------------------------------------*/ + if (!queue_if_no_path) + dm_table_run_md_queue_async(m->ti->table); -static void dispatch_queued_ios(struct multipath *m) -{ - int r; - unsigned long flags; - union map_info *info; - struct request *clone, *n; - LIST_HEAD(cl); - - spin_lock_irqsave(&m->lock, flags); - list_splice_init(&m->queued_ios, &cl); - spin_unlock_irqrestore(&m->lock, flags); - - list_for_each_entry_safe(clone, n, &cl, queuelist) { - list_del_init(&clone->queuelist); - - info = dm_get_rq_mapinfo(clone); - - r = map_io(m, clone, info, 1); - if (r < 0) { - clear_mapinfo(m, info); - dm_kill_unmapped_request(clone, r); - } else if (r == DM_MAPIO_REMAPPED) - dm_dispatch_request(clone); - else if (r == DM_MAPIO_REQUEUE) { - clear_mapinfo(m, info); - dm_requeue_unmapped_request(clone); - } - } -} - -static void process_queued_ios(struct work_struct *work) -{ - struct multipath *m = - container_of(work, struct multipath, process_queued_ios); - struct pgpath *pgpath = NULL; - unsigned must_queue = 1; - unsigned long flags; - - spin_lock_irqsave(&m->lock, flags); - - if (!m->current_pgpath) - __choose_pgpath(m, 0); - - pgpath = m->current_pgpath; - - if ((pgpath && !m->queue_io) || - (!pgpath && !m->queue_if_no_path)) - must_queue = 0; - - if (m->pg_init_required && !m->pg_init_in_progress && pgpath) - __pg_init_all_paths(m); - - spin_unlock_irqrestore(&m->lock, flags); - if (!must_queue) - dispatch_queued_ios(m); + return 0; } /* @@ -568,6 +517,8 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps int r; struct pgpath *p; struct multipath *m = ti->private; + struct request_queue *q = NULL; + const char *attached_handler_name; /* we need at least a path arg */ if (as->argc < 1) { @@ -586,13 +537,37 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps goto bad; } - if (m->hw_handler_name) { - struct request_queue *q = bdev_get_queue(p->path.dev->bdev); + if (m->retain_attached_hw_handler || m->hw_handler_name) + q = bdev_get_queue(p->path.dev->bdev); + if (m->retain_attached_hw_handler) { + attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); + if (attached_handler_name) { + /* + * Reset hw_handler_name to match the attached handler + * and clear any hw_handler_params associated with the + * ignored handler. + * + * NB. This modifies the table line to show the actual + * handler instead of the original table passed in. + */ + kfree(m->hw_handler_name); + m->hw_handler_name = attached_handler_name; + + kfree(m->hw_handler_params); + m->hw_handler_params = NULL; + } + } + + if (m->hw_handler_name) { + /* + * Increments scsi_dh reference, even when using an + * already-attached handler. + */ r = scsi_dh_attach(q, m->hw_handler_name); if (r == -EBUSY) { /* - * Already attached to different hw_handler, + * Already attached to different hw_handler: * try to reattach with correct one. */ scsi_dh_detach(q); @@ -760,7 +735,7 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m) const char *arg_name; static struct dm_arg _args[] = { - {0, 5, "invalid number of feature args"}, + {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"}, }; @@ -781,6 +756,11 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m) continue; } + if (!strcasecmp(arg_name, "retain_attached_hw_handler")) { + m->retain_attached_hw_handler = 1; + continue; + } + if (!strcasecmp(arg_name, "pg_init_retries") && (argc >= 1)) { r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error); @@ -873,8 +853,9 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc, goto bad; } - ti->num_flush_requests = 1; - ti->num_discard_requests = 1; + ti->num_flush_bios = 1; + ti->num_discard_bios = 1; + ti->num_write_same_bios = 1; return 0; @@ -909,10 +890,20 @@ static void multipath_wait_for_pg_init_completion(struct multipath *m) static void flush_multipath_work(struct multipath *m) { + unsigned long flags; + + spin_lock_irqsave(&m->lock, flags); + m->pg_init_disabled = 1; + spin_unlock_irqrestore(&m->lock, flags); + flush_workqueue(kmpath_handlerd); multipath_wait_for_pg_init_completion(m); flush_workqueue(kmultipathd); - flush_work_sync(&m->trigger_event); + flush_work(&m->trigger_event); + + spin_lock_irqsave(&m->lock, flags); + m->pg_init_disabled = 0; + spin_unlock_irqrestore(&m->lock, flags); } static void multipath_dtr(struct dm_target *ti) @@ -924,27 +915,6 @@ static void multipath_dtr(struct dm_target *ti) } /* - * Map cloned requests - */ -static int multipath_map(struct dm_target *ti, struct request *clone, - union map_info *map_context) -{ - int r; - struct multipath *m = (struct multipath *) ti->private; - - if (set_mapinfo(m, map_context) < 0) - /* ENOMEM, requeue */ - return DM_MAPIO_REQUEUE; - - clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; - r = map_io(m, clone, map_context, 0); - if (r < 0 || r == DM_MAPIO_REQUEUE) - clear_mapinfo(m, map_context); - - return r; -} - -/* * Take a path out of use. */ static int fail_path(struct pgpath *pgpath) @@ -984,7 +954,7 @@ out: */ static int reinstate_path(struct pgpath *pgpath) { - int r = 0; + int r = 0, run_queue = 0; unsigned long flags; struct multipath *m = pgpath->pg->m; @@ -1006,9 +976,9 @@ static int reinstate_path(struct pgpath *pgpath) pgpath->is_active = 1; - if (!m->nr_valid_paths++ && m->queue_size) { + if (!m->nr_valid_paths++) { m->current_pgpath = NULL; - queue_work(kmultipathd, &m->process_queued_ios); + run_queue = 1; } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { if (queue_work(kmpath_handlerd, &pgpath->activate_path.work)) m->pg_init_in_progress++; @@ -1021,6 +991,8 @@ static int reinstate_path(struct pgpath *pgpath) out: spin_unlock_irqrestore(&m->lock, flags); + if (run_queue) + dm_table_run_md_queue_async(m->ti->table); return r; } @@ -1131,7 +1103,7 @@ static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) spin_lock_irqsave(&m->lock, flags); - if (m->pg_init_count <= m->pg_init_retries) + if (m->pg_init_count <= m->pg_init_retries && !m->pg_init_disabled) m->pg_init_required = 1; else limit_reached = 1; @@ -1204,11 +1176,12 @@ static void pg_init_done(void *data, int errors) /* Activations of other paths are still on going */ goto out; - if (!m->pg_init_required) - m->queue_io = 0; - - m->pg_init_delay_retry = delay_retry; - queue_work(kmultipathd, &m->process_queued_ios); + if (m->pg_init_required) { + m->pg_init_delay_retry = delay_retry; + if (__pg_init_all_paths(m)) + goto out; + } + m->queue_io = 0; /* * Wake up any thread waiting to suspend. @@ -1224,8 +1197,26 @@ static void activate_path(struct work_struct *work) struct pgpath *pgpath = container_of(work, struct pgpath, activate_path.work); - scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), - pg_init_done, pgpath); + if (pgpath->is_active) + scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), + pg_init_done, pgpath); + else + pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED); +} + +static int noretry_error(int error) +{ + switch (error) { + case -EOPNOTSUPP: + case -EREMOTEIO: + case -EILSEQ: + case -ENODATA: + case -ENOSPC: + return 1; + } + + /* Anything else could be a path failure, so should be retried */ + return 0; } /* @@ -1251,7 +1242,7 @@ static int do_end_io(struct multipath *m, struct request *clone, if (!error && !clone->errors) return 0; /* I/O complete */ - if (error == -EOPNOTSUPP || error == -EREMOTEIO || error == -EILSEQ) + if (noretry_error(error)) return error; if (mpio->pgpath) @@ -1277,13 +1268,14 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone, { struct multipath *m = ti->private; struct dm_mpath_io *mpio = map_context->ptr; - struct pgpath *pgpath = mpio->pgpath; + struct pgpath *pgpath; struct path_selector *ps; int r; BUG_ON(!mpio); r = do_end_io(m, clone, error, mpio); + pgpath = mpio->pgpath; if (pgpath) { ps = &pgpath->pg->ps; if (ps->type->end_io) @@ -1345,8 +1337,8 @@ static void multipath_resume(struct dm_target *ti) * [priority selector-name num_ps_args [ps_args]* * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ */ -static int multipath_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) +static void multipath_status(struct dm_target *ti, status_type_t type, + unsigned status_flags, char *result, unsigned maxlen) { int sz = 0; unsigned long flags; @@ -1360,17 +1352,20 @@ static int multipath_status(struct dm_target *ti, status_type_t type, /* Features */ if (type == STATUSTYPE_INFO) - DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count); + DMEMIT("2 %u %u ", m->queue_io, m->pg_init_count); else { DMEMIT("%u ", m->queue_if_no_path + (m->pg_init_retries > 0) * 2 + - (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 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->pg_init_retries) DMEMIT("pg_init_retries %u ", m->pg_init_retries); if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs); + if (m->retain_attached_hw_handler) + DMEMIT("retain_attached_hw_handler "); } if (!m->hw_handler_name || type == STATUSTYPE_INFO) @@ -1449,8 +1444,6 @@ static int multipath_status(struct dm_target *ti, status_type_t type, } spin_unlock_irqrestore(&m->lock, flags); - - return 0; } static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) @@ -1478,7 +1471,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) } if (argc != 2) { - DMWARN("Unrecognised multipath message received."); + DMWARN("Invalid multipath message arguments. Expected 2 arguments, got %d.", argc); goto out; } @@ -1496,7 +1489,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) else if (!strcasecmp(argv[0], "fail_path")) action = fail_path; else { - DMWARN("Unrecognised multipath message received."); + DMWARN("Unrecognised multipath message received: %s", argv[0]); goto out; } @@ -1520,12 +1513,12 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd, unsigned long arg) { struct multipath *m = ti->private; + struct pgpath *pgpath; struct block_device *bdev; fmode_t mode; unsigned long flags; int r; -again: bdev = NULL; mode = 0; r = 0; @@ -1535,13 +1528,15 @@ again: if (!m->current_pgpath) __choose_pgpath(m, 0); - if (m->current_pgpath) { - bdev = m->current_pgpath->path.dev->bdev; - mode = m->current_pgpath->path.dev->mode; + pgpath = m->current_pgpath; + + if (pgpath) { + bdev = pgpath->path.dev->bdev; + mode = pgpath->path.dev->mode; } - if (m->queue_io) - r = -EAGAIN; + if ((pgpath && m->queue_io) || (!pgpath && m->queue_if_no_path)) + r = -ENOTCONN; else if (!bdev) r = -EIO; @@ -1550,13 +1545,22 @@ again: /* * Only pass ioctls through if the device sizes match exactly. */ - if (!r && ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT) - r = scsi_verify_blk_ioctl(NULL, cmd); + if (!bdev || ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT) { + int err = scsi_verify_blk_ioctl(NULL, cmd); + if (err) + r = err; + } - if (r == -EAGAIN && !fatal_signal_pending(current)) { - queue_work(kmultipathd, &m->process_queued_ios); - msleep(10); - goto again; + if (r == -ENOTCONN && !fatal_signal_pending(current)) { + spin_lock_irqsave(&m->lock, flags); + if (!m->current_pg) { + /* Path status changed, redo selection */ + __choose_pgpath(m, 0); + } + if (m->pg_init_required) + __pg_init_all_paths(m); + spin_unlock_irqrestore(&m->lock, flags); + dm_table_run_md_queue_async(m->ti->table); } return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg); @@ -1607,6 +1611,12 @@ static int multipath_busy(struct dm_target *ti) spin_lock_irqsave(&m->lock, flags); + /* pg_init in progress or no paths available */ + if (m->pg_init_in_progress || + (!m->nr_valid_paths && m->queue_if_no_path)) { + busy = 1; + goto out; + } /* Guess which priority_group will be used at next mapping time */ if (unlikely(!m->current_pgpath && m->next_pg)) pg = m->next_pg; @@ -1656,7 +1666,7 @@ out: *---------------------------------------------------------------*/ static struct target_type multipath_target = { .name = "multipath", - .version = {1, 4, 0}, + .version = {1, 7, 0}, .module = THIS_MODULE, .ctr = multipath_ctr, .dtr = multipath_dtr, |
