Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2003 Sistina Software Limited. |
| 3 | * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. |
| 4 | * |
| 5 | * This file is released under the GPL. |
| 6 | */ |
| 7 | |
Mikulas Patocka | 586e80e | 2008-10-21 17:44:59 +0100 | [diff] [blame] | 8 | #include <linux/device-mapper.h> |
| 9 | |
Mike Snitzer | f479082 | 2013-09-12 18:06:12 -0400 | [diff] [blame] | 10 | #include "dm.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include "dm-path-selector.h" |
Mike Anderson | b15546f | 2007-10-19 22:48:02 +0100 | [diff] [blame] | 12 | #include "dm-uevent.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | |
| 14 | #include <linux/ctype.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/mempool.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/pagemap.h> |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/time.h> |
| 21 | #include <linux/workqueue.h> |
Mikulas Patocka | 3599165 | 2012-06-03 00:29:58 +0100 | [diff] [blame] | 22 | #include <linux/delay.h> |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 23 | #include <scsi/scsi_dh.h> |
Arun Sharma | 60063497 | 2011-07-26 16:09:06 -0700 | [diff] [blame] | 24 | #include <linux/atomic.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 26 | #define DM_MSG_PREFIX "multipath" |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 27 | #define DM_PG_INIT_DELAY_MSECS 2000 |
| 28 | #define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
| 30 | /* Path properties */ |
| 31 | struct pgpath { |
| 32 | struct list_head list; |
| 33 | |
| 34 | struct priority_group *pg; /* Owning PG */ |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 35 | unsigned is_active; /* Path status */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | unsigned fail_count; /* Cumulative failure count */ |
| 37 | |
Josef "Jeff" Sipek | c922d5f | 2006-12-08 02:36:33 -0800 | [diff] [blame] | 38 | struct dm_path path; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 39 | struct delayed_work activate_path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | }; |
| 41 | |
| 42 | #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path) |
| 43 | |
| 44 | /* |
| 45 | * Paths are grouped into Priority Groups and numbered from 1 upwards. |
| 46 | * Each has a path selector which controls which path gets used. |
| 47 | */ |
| 48 | struct priority_group { |
| 49 | struct list_head list; |
| 50 | |
| 51 | struct multipath *m; /* Owning multipath instance */ |
| 52 | struct path_selector ps; |
| 53 | |
| 54 | unsigned pg_num; /* Reference number */ |
| 55 | unsigned bypassed; /* Temporarily bypass this PG? */ |
| 56 | |
| 57 | unsigned nr_pgpaths; /* Number of paths in PG */ |
| 58 | struct list_head pgpaths; |
| 59 | }; |
| 60 | |
| 61 | /* Multipath context */ |
| 62 | struct multipath { |
| 63 | struct list_head list; |
| 64 | struct dm_target *ti; |
| 65 | |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 66 | const char *hw_handler_name; |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 67 | char *hw_handler_params; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 68 | |
Mike Snitzer | 1fbdd2b | 2012-06-03 00:29:43 +0100 | [diff] [blame] | 69 | spinlock_t lock; |
| 70 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | unsigned nr_priority_groups; |
| 72 | struct list_head priority_groups; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 73 | |
| 74 | wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */ |
| 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | unsigned pg_init_required; /* pg_init needs calling? */ |
Alasdair G Kergon | c3cd4f6 | 2005-07-12 15:53:04 -0700 | [diff] [blame] | 77 | unsigned pg_init_in_progress; /* Only one pg_init allowed at once */ |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 78 | unsigned pg_init_delay_retry; /* Delay pg_init retry? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
| 80 | unsigned nr_valid_paths; /* Total number of usable paths */ |
| 81 | struct pgpath *current_pgpath; |
| 82 | struct priority_group *current_pg; |
| 83 | struct priority_group *next_pg; /* Switch to this PG if set */ |
| 84 | unsigned repeat_count; /* I/Os left before calling PS again */ |
| 85 | |
Mike Snitzer | 1fbdd2b | 2012-06-03 00:29:43 +0100 | [diff] [blame] | 86 | unsigned queue_io:1; /* Must we queue all I/O? */ |
| 87 | unsigned queue_if_no_path:1; /* Queue I/O if last path fails? */ |
| 88 | unsigned saved_queue_if_no_path:1; /* Saved state during suspension */ |
Mike Snitzer | a58a935 | 2012-07-27 15:08:04 +0100 | [diff] [blame] | 89 | unsigned retain_attached_hw_handler:1; /* If there's already a hw_handler present, don't change it. */ |
Shiva Krishna Merla | 954a73d | 2013-10-30 03:26:38 +0000 | [diff] [blame] | 90 | unsigned pg_init_disabled:1; /* pg_init is not currently allowed */ |
Mike Snitzer | 1fbdd2b | 2012-06-03 00:29:43 +0100 | [diff] [blame] | 91 | |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 92 | unsigned pg_init_retries; /* Number of times to retry pg_init */ |
| 93 | unsigned pg_init_count; /* Number of times pg_init called */ |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 94 | unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | struct work_struct trigger_event; |
| 97 | |
| 98 | /* |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 99 | * We must use a mempool of dm_mpath_io structs so that we |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | * can resubmit bios on error. |
| 101 | */ |
| 102 | mempool_t *mpio_pool; |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 103 | |
| 104 | struct mutex work_mutex; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | }; |
| 106 | |
| 107 | /* |
| 108 | * Context information attached to each bio we process. |
| 109 | */ |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 110 | struct dm_mpath_io { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | struct pgpath *pgpath; |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 112 | size_t nr_bytes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | }; |
| 114 | |
| 115 | typedef int (*action_fn) (struct pgpath *pgpath); |
| 116 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 117 | static struct kmem_cache *_mpio_cache; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 119 | static struct workqueue_struct *kmultipathd, *kmpath_handlerd; |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 120 | static void trigger_event(struct work_struct *work); |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 121 | static void activate_path(struct work_struct *work); |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 122 | static int __pgpath_busy(struct pgpath *pgpath); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | |
| 124 | |
| 125 | /*----------------------------------------------- |
| 126 | * Allocation routines |
| 127 | *-----------------------------------------------*/ |
| 128 | |
| 129 | static struct pgpath *alloc_pgpath(void) |
| 130 | { |
Micha³ Miros³aw | e69fae5 | 2006-10-03 01:15:34 -0700 | [diff] [blame] | 131 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | |
Mike Anderson | 224cb3e | 2008-08-29 09:36:09 +0200 | [diff] [blame] | 133 | if (pgpath) { |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 134 | pgpath->is_active = 1; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 135 | INIT_DELAYED_WORK(&pgpath->activate_path, activate_path); |
Mike Anderson | 224cb3e | 2008-08-29 09:36:09 +0200 | [diff] [blame] | 136 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | |
| 138 | return pgpath; |
| 139 | } |
| 140 | |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 141 | static void free_pgpath(struct pgpath *pgpath) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | { |
| 143 | kfree(pgpath); |
| 144 | } |
| 145 | |
| 146 | static struct priority_group *alloc_priority_group(void) |
| 147 | { |
| 148 | struct priority_group *pg; |
| 149 | |
Micha³ Miros³aw | e69fae5 | 2006-10-03 01:15:34 -0700 | [diff] [blame] | 150 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | |
Micha³ Miros³aw | e69fae5 | 2006-10-03 01:15:34 -0700 | [diff] [blame] | 152 | if (pg) |
| 153 | INIT_LIST_HEAD(&pg->pgpaths); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | |
| 155 | return pg; |
| 156 | } |
| 157 | |
| 158 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) |
| 159 | { |
| 160 | struct pgpath *pgpath, *tmp; |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 161 | struct multipath *m = ti->private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | |
| 163 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { |
| 164 | list_del(&pgpath->list); |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 165 | if (m->hw_handler_name) |
| 166 | scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | dm_put_device(ti, pgpath->path.dev); |
| 168 | free_pgpath(pgpath); |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | static void free_priority_group(struct priority_group *pg, |
| 173 | struct dm_target *ti) |
| 174 | { |
| 175 | struct path_selector *ps = &pg->ps; |
| 176 | |
| 177 | if (ps->type) { |
| 178 | ps->type->destroy(ps); |
| 179 | dm_put_path_selector(ps->type); |
| 180 | } |
| 181 | |
| 182 | free_pgpaths(&pg->pgpaths, ti); |
| 183 | kfree(pg); |
| 184 | } |
| 185 | |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 186 | static struct multipath *alloc_multipath(struct dm_target *ti) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | { |
| 188 | struct multipath *m; |
Mike Snitzer | f479082 | 2013-09-12 18:06:12 -0400 | [diff] [blame] | 189 | unsigned min_ios = dm_get_reserved_rq_based_ios(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | |
Micha³ Miros³aw | e69fae5 | 2006-10-03 01:15:34 -0700 | [diff] [blame] | 191 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | if (m) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | INIT_LIST_HEAD(&m->priority_groups); |
| 194 | spin_lock_init(&m->lock); |
| 195 | m->queue_io = 1; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 196 | m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 197 | INIT_WORK(&m->trigger_event, trigger_event); |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 198 | init_waitqueue_head(&m->pg_init_wait); |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 199 | mutex_init(&m->work_mutex); |
Mike Snitzer | f479082 | 2013-09-12 18:06:12 -0400 | [diff] [blame] | 200 | m->mpio_pool = mempool_create_slab_pool(min_ios, _mpio_cache); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | if (!m->mpio_pool) { |
| 202 | kfree(m); |
| 203 | return NULL; |
| 204 | } |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 205 | m->ti = ti; |
| 206 | ti->private = m; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | } |
| 208 | |
| 209 | return m; |
| 210 | } |
| 211 | |
| 212 | static void free_multipath(struct multipath *m) |
| 213 | { |
| 214 | struct priority_group *pg, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
| 216 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { |
| 217 | list_del(&pg->list); |
| 218 | free_priority_group(pg, m->ti); |
| 219 | } |
| 220 | |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 221 | kfree(m->hw_handler_name); |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 222 | kfree(m->hw_handler_params); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | mempool_destroy(m->mpio_pool); |
| 224 | kfree(m); |
| 225 | } |
| 226 | |
Jun'ichi Nomura | 466891f | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 227 | static int set_mapinfo(struct multipath *m, union map_info *info) |
| 228 | { |
| 229 | struct dm_mpath_io *mpio; |
| 230 | |
| 231 | mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC); |
| 232 | if (!mpio) |
| 233 | return -ENOMEM; |
| 234 | |
| 235 | memset(mpio, 0, sizeof(*mpio)); |
| 236 | info->ptr = mpio; |
| 237 | |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | static void clear_mapinfo(struct multipath *m, union map_info *info) |
| 242 | { |
| 243 | struct dm_mpath_io *mpio = info->ptr; |
| 244 | |
| 245 | info->ptr = NULL; |
| 246 | mempool_free(mpio, m->mpio_pool); |
| 247 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | |
| 249 | /*----------------------------------------------- |
| 250 | * Path selection |
| 251 | *-----------------------------------------------*/ |
| 252 | |
Hannes Reinecke | 3e9f1be | 2014-02-28 15:33:45 +0100 | [diff] [blame] | 253 | static int __pg_init_all_paths(struct multipath *m) |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 254 | { |
| 255 | struct pgpath *pgpath; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 256 | unsigned long pg_init_delay = 0; |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 257 | |
Hannes Reinecke | 17f4ff4 | 2014-02-28 15:33:42 +0100 | [diff] [blame] | 258 | if (m->pg_init_in_progress || m->pg_init_disabled) |
Hannes Reinecke | 3e9f1be | 2014-02-28 15:33:45 +0100 | [diff] [blame] | 259 | return 0; |
Hannes Reinecke | 17f4ff4 | 2014-02-28 15:33:42 +0100 | [diff] [blame] | 260 | |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 261 | m->pg_init_count++; |
| 262 | m->pg_init_required = 0; |
Hannes Reinecke | 3e9f1be | 2014-02-28 15:33:45 +0100 | [diff] [blame] | 263 | |
| 264 | /* Check here to reset pg_init_required */ |
| 265 | if (!m->current_pg) |
| 266 | return 0; |
| 267 | |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 268 | if (m->pg_init_delay_retry) |
| 269 | pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ? |
| 270 | m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS); |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 271 | list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) { |
| 272 | /* Skip failed paths */ |
| 273 | if (!pgpath->is_active) |
| 274 | continue; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 275 | if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path, |
| 276 | pg_init_delay)) |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 277 | m->pg_init_in_progress++; |
| 278 | } |
Hannes Reinecke | 3e9f1be | 2014-02-28 15:33:45 +0100 | [diff] [blame] | 279 | return m->pg_init_in_progress; |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 280 | } |
| 281 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | static void __switch_pg(struct multipath *m, struct pgpath *pgpath) |
| 283 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | m->current_pg = pgpath->pg; |
| 285 | |
| 286 | /* Must we initialise the PG first, and queue I/O till it's ready? */ |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 287 | if (m->hw_handler_name) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | m->pg_init_required = 1; |
| 289 | m->queue_io = 1; |
| 290 | } else { |
| 291 | m->pg_init_required = 0; |
| 292 | m->queue_io = 0; |
| 293 | } |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 294 | |
| 295 | m->pg_init_count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | } |
| 297 | |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 298 | static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg, |
| 299 | size_t nr_bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | { |
Josef "Jeff" Sipek | c922d5f | 2006-12-08 02:36:33 -0800 | [diff] [blame] | 301 | struct dm_path *path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 303 | path = pg->ps.type->select_path(&pg->ps, &m->repeat_count, nr_bytes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | if (!path) |
| 305 | return -ENXIO; |
| 306 | |
| 307 | m->current_pgpath = path_to_pgpath(path); |
| 308 | |
| 309 | if (m->current_pg != pg) |
| 310 | __switch_pg(m, m->current_pgpath); |
| 311 | |
| 312 | return 0; |
| 313 | } |
| 314 | |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 315 | static void __choose_pgpath(struct multipath *m, size_t nr_bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | { |
| 317 | struct priority_group *pg; |
| 318 | unsigned bypassed = 1; |
| 319 | |
| 320 | if (!m->nr_valid_paths) |
| 321 | goto failed; |
| 322 | |
| 323 | /* Were we instructed to switch PG? */ |
| 324 | if (m->next_pg) { |
| 325 | pg = m->next_pg; |
| 326 | m->next_pg = NULL; |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 327 | if (!__choose_path_in_pg(m, pg, nr_bytes)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | return; |
| 329 | } |
| 330 | |
| 331 | /* Don't change PG until it has no remaining paths */ |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 332 | if (m->current_pg && !__choose_path_in_pg(m, m->current_pg, nr_bytes)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | return; |
| 334 | |
| 335 | /* |
| 336 | * Loop through priority groups until we find a valid path. |
| 337 | * First time we skip PGs marked 'bypassed'. |
Mike Christie | f220fd4 | 2012-06-03 00:29:45 +0100 | [diff] [blame] | 338 | * Second time we only try the ones we skipped, but set |
| 339 | * pg_init_delay_retry so we do not hammer controllers. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | */ |
| 341 | do { |
| 342 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 343 | if (pg->bypassed == bypassed) |
| 344 | continue; |
Mike Christie | f220fd4 | 2012-06-03 00:29:45 +0100 | [diff] [blame] | 345 | if (!__choose_path_in_pg(m, pg, nr_bytes)) { |
| 346 | if (!bypassed) |
| 347 | m->pg_init_delay_retry = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | return; |
Mike Christie | f220fd4 | 2012-06-03 00:29:45 +0100 | [diff] [blame] | 349 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | } |
| 351 | } while (bypassed--); |
| 352 | |
| 353 | failed: |
| 354 | m->current_pgpath = NULL; |
| 355 | m->current_pg = NULL; |
| 356 | } |
| 357 | |
Kiyoshi Ueda | 45e1572 | 2006-12-08 02:41:10 -0800 | [diff] [blame] | 358 | /* |
| 359 | * Check whether bios must be queued in the device-mapper core rather |
| 360 | * than here in the target. |
| 361 | * |
| 362 | * m->lock must be held on entry. |
| 363 | * |
| 364 | * If m->queue_if_no_path and m->saved_queue_if_no_path hold the |
| 365 | * same value then we are not between multipath_presuspend() |
| 366 | * and multipath_resume() calls and we have no need to check |
| 367 | * for the DMF_NOFLUSH_SUSPENDING flag. |
| 368 | */ |
| 369 | static int __must_push_back(struct multipath *m) |
| 370 | { |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 371 | return (m->queue_if_no_path || |
| 372 | (m->queue_if_no_path != m->saved_queue_if_no_path && |
| 373 | dm_noflush_suspending(m->ti))); |
Kiyoshi Ueda | 45e1572 | 2006-12-08 02:41:10 -0800 | [diff] [blame] | 374 | } |
| 375 | |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 376 | #define pg_ready(m) (!(m)->queue_io && !(m)->pg_init_required) |
| 377 | |
Hannes Reinecke | 36fcffc | 2014-02-28 15:33:47 +0100 | [diff] [blame^] | 378 | /* |
| 379 | * Map cloned requests |
| 380 | */ |
| 381 | static int multipath_map(struct dm_target *ti, struct request *clone, |
| 382 | union map_info *map_context) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | { |
Hannes Reinecke | 36fcffc | 2014-02-28 15:33:47 +0100 | [diff] [blame^] | 384 | struct multipath *m = (struct multipath *) ti->private; |
Hannes Reinecke | e3bde04 | 2014-02-28 15:33:46 +0100 | [diff] [blame] | 385 | int r = DM_MAPIO_REQUEUE; |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 386 | size_t nr_bytes = blk_rq_bytes(clone); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | unsigned long flags; |
| 388 | struct pgpath *pgpath; |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 389 | struct block_device *bdev; |
Hannes Reinecke | e3bde04 | 2014-02-28 15:33:46 +0100 | [diff] [blame] | 390 | struct dm_mpath_io *mpio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | |
| 392 | spin_lock_irqsave(&m->lock, flags); |
| 393 | |
| 394 | /* Do we need to select a new pgpath? */ |
| 395 | if (!m->current_pgpath || |
| 396 | (!m->queue_io && (m->repeat_count && --m->repeat_count == 0))) |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 397 | __choose_pgpath(m, nr_bytes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | |
| 399 | pgpath = m->current_pgpath; |
| 400 | |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 401 | if (pgpath) { |
| 402 | if (pg_ready(m)) { |
Hannes Reinecke | e3bde04 | 2014-02-28 15:33:46 +0100 | [diff] [blame] | 403 | if (set_mapinfo(m, map_context) < 0) |
| 404 | /* ENOMEM, requeue */ |
| 405 | goto out_unlock; |
| 406 | |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 407 | bdev = pgpath->path.dev->bdev; |
| 408 | clone->q = bdev_get_queue(bdev); |
| 409 | clone->rq_disk = bdev->bd_disk; |
Hannes Reinecke | e3bde04 | 2014-02-28 15:33:46 +0100 | [diff] [blame] | 410 | clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; |
| 411 | mpio = map_context->ptr; |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 412 | mpio->pgpath = pgpath; |
| 413 | mpio->nr_bytes = nr_bytes; |
| 414 | if (pgpath->pg->ps.type->start_io) |
| 415 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, |
| 416 | &pgpath->path, |
| 417 | nr_bytes); |
Hannes Reinecke | e3bde04 | 2014-02-28 15:33:46 +0100 | [diff] [blame] | 418 | r = DM_MAPIO_REMAPPED; |
| 419 | goto out_unlock; |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 420 | } |
Hannes Reinecke | e3bde04 | 2014-02-28 15:33:46 +0100 | [diff] [blame] | 421 | __pg_init_all_paths(m); |
| 422 | } else if (!__must_push_back(m)) |
| 423 | r = -EIO; /* Failed */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | |
Hannes Reinecke | e3bde04 | 2014-02-28 15:33:46 +0100 | [diff] [blame] | 425 | out_unlock: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | spin_unlock_irqrestore(&m->lock, flags); |
| 427 | |
| 428 | return r; |
| 429 | } |
| 430 | |
| 431 | /* |
| 432 | * If we run out of usable paths, should we queue I/O or error it? |
| 433 | */ |
Alasdair G Kergon | 485ef69 | 2005-09-27 21:45:45 -0700 | [diff] [blame] | 434 | static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, |
| 435 | unsigned save_old_value) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | { |
| 437 | unsigned long flags; |
| 438 | |
| 439 | spin_lock_irqsave(&m->lock, flags); |
| 440 | |
Alasdair G Kergon | 485ef69 | 2005-09-27 21:45:45 -0700 | [diff] [blame] | 441 | if (save_old_value) |
| 442 | m->saved_queue_if_no_path = m->queue_if_no_path; |
| 443 | else |
| 444 | m->saved_queue_if_no_path = queue_if_no_path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | m->queue_if_no_path = queue_if_no_path; |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 446 | if (!m->queue_if_no_path) |
Hannes Reinecke | 3e9f1be | 2014-02-28 15:33:45 +0100 | [diff] [blame] | 447 | dm_table_run_md_queue_async(m->ti->table); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | |
| 449 | spin_unlock_irqrestore(&m->lock, flags); |
| 450 | |
| 451 | return 0; |
| 452 | } |
| 453 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | /* |
| 455 | * An event is triggered whenever a path is taken out of use. |
| 456 | * Includes path failure and PG bypass. |
| 457 | */ |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 458 | static void trigger_event(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | { |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 460 | struct multipath *m = |
| 461 | container_of(work, struct multipath, trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | |
| 463 | dm_table_event(m->ti->table); |
| 464 | } |
| 465 | |
| 466 | /*----------------------------------------------------------------- |
| 467 | * Constructor/argument parsing: |
| 468 | * <#multipath feature args> [<arg>]* |
| 469 | * <#hw_handler args> [hw_handler [<arg>]*] |
| 470 | * <#priority groups> |
| 471 | * <initial priority group> |
| 472 | * [<selector> <#selector args> [<arg>]* |
| 473 | * <#paths> <#per-path selector args> |
| 474 | * [<path> [<arg>]* ]+ ]+ |
| 475 | *---------------------------------------------------------------*/ |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 476 | static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | struct dm_target *ti) |
| 478 | { |
| 479 | int r; |
| 480 | struct path_selector_type *pst; |
| 481 | unsigned ps_argc; |
| 482 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 483 | static struct dm_arg _args[] = { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 484 | {0, 1024, "invalid number of path selector args"}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | }; |
| 486 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 487 | pst = dm_get_path_selector(dm_shift_arg(as)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | if (!pst) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 489 | ti->error = "unknown path selector type"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | return -EINVAL; |
| 491 | } |
| 492 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 493 | r = dm_read_arg_group(_args, as, &ps_argc, &ti->error); |
Mikulas Patocka | 371b2e3 | 2008-07-21 12:00:24 +0100 | [diff] [blame] | 494 | if (r) { |
| 495 | dm_put_path_selector(pst); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | return -EINVAL; |
Mikulas Patocka | 371b2e3 | 2008-07-21 12:00:24 +0100 | [diff] [blame] | 497 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | |
| 499 | r = pst->create(&pg->ps, ps_argc, as->argv); |
| 500 | if (r) { |
| 501 | dm_put_path_selector(pst); |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 502 | ti->error = "path selector constructor failed"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | return r; |
| 504 | } |
| 505 | |
| 506 | pg->ps.type = pst; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 507 | dm_consume_args(as, ps_argc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | |
| 509 | return 0; |
| 510 | } |
| 511 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 512 | static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | struct dm_target *ti) |
| 514 | { |
| 515 | int r; |
| 516 | struct pgpath *p; |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 517 | struct multipath *m = ti->private; |
Mike Snitzer | a58a935 | 2012-07-27 15:08:04 +0100 | [diff] [blame] | 518 | struct request_queue *q = NULL; |
| 519 | const char *attached_handler_name; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | |
| 521 | /* we need at least a path arg */ |
| 522 | if (as->argc < 1) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 523 | ti->error = "no device given"; |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 524 | return ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | } |
| 526 | |
| 527 | p = alloc_pgpath(); |
| 528 | if (!p) |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 529 | return ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 531 | r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table), |
Nikanth Karthikesan | 8215d6e | 2010-03-06 02:32:27 +0000 | [diff] [blame] | 532 | &p->path.dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | if (r) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 534 | ti->error = "error getting device"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | goto bad; |
| 536 | } |
| 537 | |
Mike Snitzer | a58a935 | 2012-07-27 15:08:04 +0100 | [diff] [blame] | 538 | if (m->retain_attached_hw_handler || m->hw_handler_name) |
| 539 | q = bdev_get_queue(p->path.dev->bdev); |
Hannes Reinecke | a0cf7ea | 2009-06-22 10:12:11 +0100 | [diff] [blame] | 540 | |
Mike Snitzer | a58a935 | 2012-07-27 15:08:04 +0100 | [diff] [blame] | 541 | if (m->retain_attached_hw_handler) { |
| 542 | attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); |
| 543 | if (attached_handler_name) { |
| 544 | /* |
| 545 | * Reset hw_handler_name to match the attached handler |
| 546 | * and clear any hw_handler_params associated with the |
| 547 | * ignored handler. |
| 548 | * |
| 549 | * NB. This modifies the table line to show the actual |
| 550 | * handler instead of the original table passed in. |
| 551 | */ |
| 552 | kfree(m->hw_handler_name); |
| 553 | m->hw_handler_name = attached_handler_name; |
| 554 | |
| 555 | kfree(m->hw_handler_params); |
| 556 | m->hw_handler_params = NULL; |
| 557 | } |
| 558 | } |
| 559 | |
| 560 | if (m->hw_handler_name) { |
| 561 | /* |
| 562 | * Increments scsi_dh reference, even when using an |
| 563 | * already-attached handler. |
| 564 | */ |
Hannes Reinecke | a0cf7ea | 2009-06-22 10:12:11 +0100 | [diff] [blame] | 565 | r = scsi_dh_attach(q, m->hw_handler_name); |
| 566 | if (r == -EBUSY) { |
| 567 | /* |
Mike Snitzer | a58a935 | 2012-07-27 15:08:04 +0100 | [diff] [blame] | 568 | * Already attached to different hw_handler: |
Hannes Reinecke | a0cf7ea | 2009-06-22 10:12:11 +0100 | [diff] [blame] | 569 | * try to reattach with correct one. |
| 570 | */ |
| 571 | scsi_dh_detach(q); |
| 572 | r = scsi_dh_attach(q, m->hw_handler_name); |
| 573 | } |
| 574 | |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 575 | if (r < 0) { |
Hannes Reinecke | a0cf7ea | 2009-06-22 10:12:11 +0100 | [diff] [blame] | 576 | ti->error = "error attaching hardware handler"; |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 577 | dm_put_device(ti, p->path.dev); |
| 578 | goto bad; |
| 579 | } |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 580 | |
| 581 | if (m->hw_handler_params) { |
| 582 | r = scsi_dh_set_params(q, m->hw_handler_params); |
| 583 | if (r < 0) { |
| 584 | ti->error = "unable to set hardware " |
| 585 | "handler parameters"; |
| 586 | scsi_dh_detach(q); |
| 587 | dm_put_device(ti, p->path.dev); |
| 588 | goto bad; |
| 589 | } |
| 590 | } |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 591 | } |
| 592 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
| 594 | if (r) { |
| 595 | dm_put_device(ti, p->path.dev); |
| 596 | goto bad; |
| 597 | } |
| 598 | |
| 599 | return p; |
| 600 | |
| 601 | bad: |
| 602 | free_pgpath(p); |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 603 | return ERR_PTR(r); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 604 | } |
| 605 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 606 | static struct priority_group *parse_priority_group(struct dm_arg_set *as, |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 607 | struct multipath *m) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | { |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 609 | static struct dm_arg _args[] = { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 610 | {1, 1024, "invalid number of paths"}, |
| 611 | {0, 1024, "invalid number of selector args"} |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | }; |
| 613 | |
| 614 | int r; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 615 | unsigned i, nr_selector_args, nr_args; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 616 | struct priority_group *pg; |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 617 | struct dm_target *ti = m->ti; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 618 | |
| 619 | if (as->argc < 2) { |
| 620 | as->argc = 0; |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 621 | ti->error = "not enough priority group arguments"; |
| 622 | return ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | } |
| 624 | |
| 625 | pg = alloc_priority_group(); |
| 626 | if (!pg) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 627 | ti->error = "couldn't allocate priority group"; |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 628 | return ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | } |
| 630 | pg->m = m; |
| 631 | |
| 632 | r = parse_path_selector(as, pg, ti); |
| 633 | if (r) |
| 634 | goto bad; |
| 635 | |
| 636 | /* |
| 637 | * read the paths |
| 638 | */ |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 639 | r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | if (r) |
| 641 | goto bad; |
| 642 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 643 | r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | if (r) |
| 645 | goto bad; |
| 646 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 647 | nr_args = 1 + nr_selector_args; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | for (i = 0; i < pg->nr_pgpaths; i++) { |
| 649 | struct pgpath *pgpath; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 650 | struct dm_arg_set path_args; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 652 | if (as->argc < nr_args) { |
Mikulas Patocka | 148acff | 2008-07-21 12:00:30 +0100 | [diff] [blame] | 653 | ti->error = "not enough path parameters"; |
Alasdair G Kergon | 6bbf79a | 2010-08-12 04:13:49 +0100 | [diff] [blame] | 654 | r = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | goto bad; |
Mikulas Patocka | 148acff | 2008-07-21 12:00:30 +0100 | [diff] [blame] | 656 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 658 | path_args.argc = nr_args; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | path_args.argv = as->argv; |
| 660 | |
| 661 | pgpath = parse_path(&path_args, &pg->ps, ti); |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 662 | if (IS_ERR(pgpath)) { |
| 663 | r = PTR_ERR(pgpath); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | goto bad; |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 665 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | |
| 667 | pgpath->pg = pg; |
| 668 | list_add_tail(&pgpath->list, &pg->pgpaths); |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 669 | dm_consume_args(as, nr_args); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | } |
| 671 | |
| 672 | return pg; |
| 673 | |
| 674 | bad: |
| 675 | free_priority_group(pg, ti); |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 676 | return ERR_PTR(r); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | } |
| 678 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 679 | static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 681 | unsigned hw_argc; |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 682 | int ret; |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 683 | struct dm_target *ti = m->ti; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 684 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 685 | static struct dm_arg _args[] = { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 686 | {0, 1024, "invalid number of hardware handler args"}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | }; |
| 688 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 689 | if (dm_read_arg_group(_args, as, &hw_argc, &ti->error)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | return -EINVAL; |
| 691 | |
| 692 | if (!hw_argc) |
| 693 | return 0; |
| 694 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 695 | m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL); |
Mike Snitzer | 510193a | 2012-05-12 01:43:21 +0100 | [diff] [blame] | 696 | if (!try_then_request_module(scsi_dh_handler_exist(m->hw_handler_name), |
| 697 | "scsi_dh_%s", m->hw_handler_name)) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 698 | ti->error = "unknown hardware handler type"; |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 699 | ret = -EINVAL; |
| 700 | goto fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | } |
Chandra Seetharaman | 14e98c5 | 2008-11-13 23:39:06 +0000 | [diff] [blame] | 702 | |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 703 | if (hw_argc > 1) { |
| 704 | char *p; |
| 705 | int i, j, len = 4; |
| 706 | |
| 707 | for (i = 0; i <= hw_argc - 2; i++) |
| 708 | len += strlen(as->argv[i]) + 1; |
| 709 | p = m->hw_handler_params = kzalloc(len, GFP_KERNEL); |
| 710 | if (!p) { |
| 711 | ti->error = "memory allocation failed"; |
| 712 | ret = -ENOMEM; |
| 713 | goto fail; |
| 714 | } |
| 715 | j = sprintf(p, "%d", hw_argc - 1); |
| 716 | for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1) |
| 717 | j = sprintf(p, "%s", as->argv[i]); |
| 718 | } |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 719 | dm_consume_args(as, hw_argc - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | |
| 721 | return 0; |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 722 | fail: |
| 723 | kfree(m->hw_handler_name); |
| 724 | m->hw_handler_name = NULL; |
| 725 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | } |
| 727 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 728 | static int parse_features(struct dm_arg_set *as, struct multipath *m) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 729 | { |
| 730 | int r; |
| 731 | unsigned argc; |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 732 | struct dm_target *ti = m->ti; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 733 | const char *arg_name; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 735 | static struct dm_arg _args[] = { |
Mike Snitzer | a58a935 | 2012-07-27 15:08:04 +0100 | [diff] [blame] | 736 | {0, 6, "invalid number of feature args"}, |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 737 | {1, 50, "pg_init_retries must be between 1 and 50"}, |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 738 | {0, 60000, "pg_init_delay_msecs must be between 0 and 60000"}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | }; |
| 740 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 741 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | if (r) |
| 743 | return -EINVAL; |
| 744 | |
| 745 | if (!argc) |
| 746 | return 0; |
| 747 | |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 748 | do { |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 749 | arg_name = dm_shift_arg(as); |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 750 | argc--; |
| 751 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 752 | if (!strcasecmp(arg_name, "queue_if_no_path")) { |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 753 | r = queue_if_no_path(m, 1, 0); |
| 754 | continue; |
| 755 | } |
| 756 | |
Mike Snitzer | a58a935 | 2012-07-27 15:08:04 +0100 | [diff] [blame] | 757 | if (!strcasecmp(arg_name, "retain_attached_hw_handler")) { |
| 758 | m->retain_attached_hw_handler = 1; |
| 759 | continue; |
| 760 | } |
| 761 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 762 | if (!strcasecmp(arg_name, "pg_init_retries") && |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 763 | (argc >= 1)) { |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 764 | r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error); |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 765 | argc--; |
| 766 | continue; |
| 767 | } |
| 768 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 769 | if (!strcasecmp(arg_name, "pg_init_delay_msecs") && |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 770 | (argc >= 1)) { |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 771 | r = dm_read_arg(_args + 2, as, &m->pg_init_delay_msecs, &ti->error); |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 772 | argc--; |
| 773 | continue; |
| 774 | } |
| 775 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | ti->error = "Unrecognised multipath feature request"; |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 777 | r = -EINVAL; |
| 778 | } while (argc && !r); |
| 779 | |
| 780 | return r; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | } |
| 782 | |
| 783 | static int multipath_ctr(struct dm_target *ti, unsigned int argc, |
| 784 | char **argv) |
| 785 | { |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 786 | /* target arguments */ |
| 787 | static struct dm_arg _args[] = { |
Mike Snitzer | a490a07 | 2011-03-24 13:54:33 +0000 | [diff] [blame] | 788 | {0, 1024, "invalid number of priority groups"}, |
| 789 | {0, 1024, "invalid initial priority group number"}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 790 | }; |
| 791 | |
| 792 | int r; |
| 793 | struct multipath *m; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 794 | struct dm_arg_set as; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | unsigned pg_count = 0; |
| 796 | unsigned next_pg_num; |
| 797 | |
| 798 | as.argc = argc; |
| 799 | as.argv = argv; |
| 800 | |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 801 | m = alloc_multipath(ti); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 802 | if (!m) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 803 | ti->error = "can't allocate multipath"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 804 | return -EINVAL; |
| 805 | } |
| 806 | |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 807 | r = parse_features(&as, m); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | if (r) |
| 809 | goto bad; |
| 810 | |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 811 | r = parse_hw_handler(&as, m); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 812 | if (r) |
| 813 | goto bad; |
| 814 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 815 | r = dm_read_arg(_args, &as, &m->nr_priority_groups, &ti->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 816 | if (r) |
| 817 | goto bad; |
| 818 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 819 | r = dm_read_arg(_args + 1, &as, &next_pg_num, &ti->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 820 | if (r) |
| 821 | goto bad; |
| 822 | |
Mike Snitzer | a490a07 | 2011-03-24 13:54:33 +0000 | [diff] [blame] | 823 | if ((!m->nr_priority_groups && next_pg_num) || |
| 824 | (m->nr_priority_groups && !next_pg_num)) { |
| 825 | ti->error = "invalid initial priority group"; |
| 826 | r = -EINVAL; |
| 827 | goto bad; |
| 828 | } |
| 829 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | /* parse the priority groups */ |
| 831 | while (as.argc) { |
| 832 | struct priority_group *pg; |
| 833 | |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 834 | pg = parse_priority_group(&as, m); |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 835 | if (IS_ERR(pg)) { |
| 836 | r = PTR_ERR(pg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | goto bad; |
| 838 | } |
| 839 | |
| 840 | m->nr_valid_paths += pg->nr_pgpaths; |
| 841 | list_add_tail(&pg->list, &m->priority_groups); |
| 842 | pg_count++; |
| 843 | pg->pg_num = pg_count; |
| 844 | if (!--next_pg_num) |
| 845 | m->next_pg = pg; |
| 846 | } |
| 847 | |
| 848 | if (pg_count != m->nr_priority_groups) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 849 | ti->error = "priority group count mismatch"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | r = -EINVAL; |
| 851 | goto bad; |
| 852 | } |
| 853 | |
Alasdair G Kergon | 55a62ee | 2013-03-01 22:45:47 +0000 | [diff] [blame] | 854 | ti->num_flush_bios = 1; |
| 855 | ti->num_discard_bios = 1; |
Mike Snitzer | 042bcef | 2013-05-10 14:37:16 +0100 | [diff] [blame] | 856 | ti->num_write_same_bios = 1; |
Mikulas Patocka | 8627921 | 2009-06-22 10:12:24 +0100 | [diff] [blame] | 857 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | return 0; |
| 859 | |
| 860 | bad: |
| 861 | free_multipath(m); |
| 862 | return r; |
| 863 | } |
| 864 | |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 865 | static void multipath_wait_for_pg_init_completion(struct multipath *m) |
| 866 | { |
| 867 | DECLARE_WAITQUEUE(wait, current); |
| 868 | unsigned long flags; |
| 869 | |
| 870 | add_wait_queue(&m->pg_init_wait, &wait); |
| 871 | |
| 872 | while (1) { |
| 873 | set_current_state(TASK_UNINTERRUPTIBLE); |
| 874 | |
| 875 | spin_lock_irqsave(&m->lock, flags); |
| 876 | if (!m->pg_init_in_progress) { |
| 877 | spin_unlock_irqrestore(&m->lock, flags); |
| 878 | break; |
| 879 | } |
| 880 | spin_unlock_irqrestore(&m->lock, flags); |
| 881 | |
| 882 | io_schedule(); |
| 883 | } |
| 884 | set_current_state(TASK_RUNNING); |
| 885 | |
| 886 | remove_wait_queue(&m->pg_init_wait, &wait); |
| 887 | } |
| 888 | |
| 889 | static void flush_multipath_work(struct multipath *m) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 890 | { |
Shiva Krishna Merla | 954a73d | 2013-10-30 03:26:38 +0000 | [diff] [blame] | 891 | unsigned long flags; |
| 892 | |
| 893 | spin_lock_irqsave(&m->lock, flags); |
| 894 | m->pg_init_disabled = 1; |
| 895 | spin_unlock_irqrestore(&m->lock, flags); |
| 896 | |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 897 | flush_workqueue(kmpath_handlerd); |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 898 | multipath_wait_for_pg_init_completion(m); |
Alasdair G Kergon | a044d01 | 2005-07-12 15:53:02 -0700 | [diff] [blame] | 899 | flush_workqueue(kmultipathd); |
Tejun Heo | 4382973 | 2012-08-20 14:51:24 -0700 | [diff] [blame] | 900 | flush_work(&m->trigger_event); |
Shiva Krishna Merla | 954a73d | 2013-10-30 03:26:38 +0000 | [diff] [blame] | 901 | |
| 902 | spin_lock_irqsave(&m->lock, flags); |
| 903 | m->pg_init_disabled = 0; |
| 904 | spin_unlock_irqrestore(&m->lock, flags); |
Kiyoshi Ueda | 6df400a | 2009-12-10 23:52:19 +0000 | [diff] [blame] | 905 | } |
| 906 | |
| 907 | static void multipath_dtr(struct dm_target *ti) |
| 908 | { |
| 909 | struct multipath *m = ti->private; |
| 910 | |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 911 | flush_multipath_work(m); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 912 | free_multipath(m); |
| 913 | } |
| 914 | |
| 915 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 916 | * Take a path out of use. |
| 917 | */ |
| 918 | static int fail_path(struct pgpath *pgpath) |
| 919 | { |
| 920 | unsigned long flags; |
| 921 | struct multipath *m = pgpath->pg->m; |
| 922 | |
| 923 | spin_lock_irqsave(&m->lock, flags); |
| 924 | |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 925 | if (!pgpath->is_active) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 926 | goto out; |
| 927 | |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 928 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 929 | |
| 930 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 931 | pgpath->is_active = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 932 | pgpath->fail_count++; |
| 933 | |
| 934 | m->nr_valid_paths--; |
| 935 | |
| 936 | if (pgpath == m->current_pgpath) |
| 937 | m->current_pgpath = NULL; |
| 938 | |
Mike Anderson | b15546f | 2007-10-19 22:48:02 +0100 | [diff] [blame] | 939 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
| 940 | pgpath->path.dev->name, m->nr_valid_paths); |
| 941 | |
Alasdair G Kergon | fe9cf30 | 2009-01-06 03:05:13 +0000 | [diff] [blame] | 942 | schedule_work(&m->trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 943 | |
| 944 | out: |
| 945 | spin_unlock_irqrestore(&m->lock, flags); |
| 946 | |
| 947 | return 0; |
| 948 | } |
| 949 | |
| 950 | /* |
| 951 | * Reinstate a previously-failed path |
| 952 | */ |
| 953 | static int reinstate_path(struct pgpath *pgpath) |
| 954 | { |
| 955 | int r = 0; |
| 956 | unsigned long flags; |
| 957 | struct multipath *m = pgpath->pg->m; |
| 958 | |
| 959 | spin_lock_irqsave(&m->lock, flags); |
| 960 | |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 961 | if (pgpath->is_active) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 962 | goto out; |
| 963 | |
Alasdair G Kergon | def052d | 2008-07-21 12:00:31 +0100 | [diff] [blame] | 964 | if (!pgpath->pg->ps.type->reinstate_path) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 965 | DMWARN("Reinstate path not supported by path selector %s", |
| 966 | pgpath->pg->ps.type->name); |
| 967 | r = -EINVAL; |
| 968 | goto out; |
| 969 | } |
| 970 | |
| 971 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); |
| 972 | if (r) |
| 973 | goto out; |
| 974 | |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 975 | pgpath->is_active = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 977 | if (!m->nr_valid_paths++) { |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 978 | m->current_pgpath = NULL; |
Hannes Reinecke | 3e9f1be | 2014-02-28 15:33:45 +0100 | [diff] [blame] | 979 | dm_table_run_md_queue_async(m->ti->table); |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 980 | } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 981 | if (queue_work(kmpath_handlerd, &pgpath->activate_path.work)) |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 982 | m->pg_init_in_progress++; |
| 983 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | |
Mike Anderson | b15546f | 2007-10-19 22:48:02 +0100 | [diff] [blame] | 985 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
| 986 | pgpath->path.dev->name, m->nr_valid_paths); |
| 987 | |
Alasdair G Kergon | fe9cf30 | 2009-01-06 03:05:13 +0000 | [diff] [blame] | 988 | schedule_work(&m->trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 989 | |
| 990 | out: |
| 991 | spin_unlock_irqrestore(&m->lock, flags); |
| 992 | |
| 993 | return r; |
| 994 | } |
| 995 | |
| 996 | /* |
| 997 | * Fail or reinstate all paths that match the provided struct dm_dev. |
| 998 | */ |
| 999 | static int action_dev(struct multipath *m, struct dm_dev *dev, |
| 1000 | action_fn action) |
| 1001 | { |
Mike Snitzer | 19040c0 | 2011-03-24 13:54:31 +0000 | [diff] [blame] | 1002 | int r = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | struct pgpath *pgpath; |
| 1004 | struct priority_group *pg; |
| 1005 | |
| 1006 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1007 | list_for_each_entry(pgpath, &pg->pgpaths, list) { |
| 1008 | if (pgpath->path.dev == dev) |
| 1009 | r = action(pgpath); |
| 1010 | } |
| 1011 | } |
| 1012 | |
| 1013 | return r; |
| 1014 | } |
| 1015 | |
| 1016 | /* |
| 1017 | * Temporarily try to avoid having to use the specified PG |
| 1018 | */ |
| 1019 | static void bypass_pg(struct multipath *m, struct priority_group *pg, |
| 1020 | int bypassed) |
| 1021 | { |
| 1022 | unsigned long flags; |
| 1023 | |
| 1024 | spin_lock_irqsave(&m->lock, flags); |
| 1025 | |
| 1026 | pg->bypassed = bypassed; |
| 1027 | m->current_pgpath = NULL; |
| 1028 | m->current_pg = NULL; |
| 1029 | |
| 1030 | spin_unlock_irqrestore(&m->lock, flags); |
| 1031 | |
Alasdair G Kergon | fe9cf30 | 2009-01-06 03:05:13 +0000 | [diff] [blame] | 1032 | schedule_work(&m->trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1033 | } |
| 1034 | |
| 1035 | /* |
| 1036 | * Switch to using the specified PG from the next I/O that gets mapped |
| 1037 | */ |
| 1038 | static int switch_pg_num(struct multipath *m, const char *pgstr) |
| 1039 | { |
| 1040 | struct priority_group *pg; |
| 1041 | unsigned pgnum; |
| 1042 | unsigned long flags; |
Mikulas Patocka | 31998ef | 2012-03-28 18:41:26 +0100 | [diff] [blame] | 1043 | char dummy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1044 | |
Mikulas Patocka | 31998ef | 2012-03-28 18:41:26 +0100 | [diff] [blame] | 1045 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1046 | (pgnum > m->nr_priority_groups)) { |
| 1047 | DMWARN("invalid PG number supplied to switch_pg_num"); |
| 1048 | return -EINVAL; |
| 1049 | } |
| 1050 | |
| 1051 | spin_lock_irqsave(&m->lock, flags); |
| 1052 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1053 | pg->bypassed = 0; |
| 1054 | if (--pgnum) |
| 1055 | continue; |
| 1056 | |
| 1057 | m->current_pgpath = NULL; |
| 1058 | m->current_pg = NULL; |
| 1059 | m->next_pg = pg; |
| 1060 | } |
| 1061 | spin_unlock_irqrestore(&m->lock, flags); |
| 1062 | |
Alasdair G Kergon | fe9cf30 | 2009-01-06 03:05:13 +0000 | [diff] [blame] | 1063 | schedule_work(&m->trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1064 | return 0; |
| 1065 | } |
| 1066 | |
| 1067 | /* |
| 1068 | * Set/clear bypassed status of a PG. |
| 1069 | * PGs are numbered upwards from 1 in the order they were declared. |
| 1070 | */ |
| 1071 | static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) |
| 1072 | { |
| 1073 | struct priority_group *pg; |
| 1074 | unsigned pgnum; |
Mikulas Patocka | 31998ef | 2012-03-28 18:41:26 +0100 | [diff] [blame] | 1075 | char dummy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | |
Mikulas Patocka | 31998ef | 2012-03-28 18:41:26 +0100 | [diff] [blame] | 1077 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1078 | (pgnum > m->nr_priority_groups)) { |
| 1079 | DMWARN("invalid PG number supplied to bypass_pg"); |
| 1080 | return -EINVAL; |
| 1081 | } |
| 1082 | |
| 1083 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1084 | if (!--pgnum) |
| 1085 | break; |
| 1086 | } |
| 1087 | |
| 1088 | bypass_pg(m, pg, bypassed); |
| 1089 | return 0; |
| 1090 | } |
| 1091 | |
| 1092 | /* |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 1093 | * Should we retry pg_init immediately? |
| 1094 | */ |
| 1095 | static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) |
| 1096 | { |
| 1097 | unsigned long flags; |
| 1098 | int limit_reached = 0; |
| 1099 | |
| 1100 | spin_lock_irqsave(&m->lock, flags); |
| 1101 | |
Shiva Krishna Merla | 954a73d | 2013-10-30 03:26:38 +0000 | [diff] [blame] | 1102 | if (m->pg_init_count <= m->pg_init_retries && !m->pg_init_disabled) |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 1103 | m->pg_init_required = 1; |
| 1104 | else |
| 1105 | limit_reached = 1; |
| 1106 | |
| 1107 | spin_unlock_irqrestore(&m->lock, flags); |
| 1108 | |
| 1109 | return limit_reached; |
| 1110 | } |
| 1111 | |
Chandra Seetharaman | 3ae31f6 | 2009-10-21 09:22:46 -0700 | [diff] [blame] | 1112 | static void pg_init_done(void *data, int errors) |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1113 | { |
Moger, Babu | 83c0d5d | 2010-03-06 02:29:45 +0000 | [diff] [blame] | 1114 | struct pgpath *pgpath = data; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1115 | struct priority_group *pg = pgpath->pg; |
| 1116 | struct multipath *m = pg->m; |
| 1117 | unsigned long flags; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1118 | unsigned delay_retry = 0; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1119 | |
| 1120 | /* device or driver problems */ |
| 1121 | switch (errors) { |
| 1122 | case SCSI_DH_OK: |
| 1123 | break; |
| 1124 | case SCSI_DH_NOSYS: |
| 1125 | if (!m->hw_handler_name) { |
| 1126 | errors = 0; |
| 1127 | break; |
| 1128 | } |
Moger, Babu | f7b934c | 2010-03-06 02:29:49 +0000 | [diff] [blame] | 1129 | DMERR("Could not failover the device: Handler scsi_dh_%s " |
| 1130 | "Error %d.", m->hw_handler_name, errors); |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1131 | /* |
| 1132 | * Fail path for now, so we do not ping pong |
| 1133 | */ |
| 1134 | fail_path(pgpath); |
| 1135 | break; |
| 1136 | case SCSI_DH_DEV_TEMP_BUSY: |
| 1137 | /* |
| 1138 | * Probably doing something like FW upgrade on the |
| 1139 | * controller so try the other pg. |
| 1140 | */ |
| 1141 | bypass_pg(m, pg, 1); |
| 1142 | break; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1143 | case SCSI_DH_RETRY: |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1144 | /* Wait before retrying. */ |
| 1145 | delay_retry = 1; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1146 | case SCSI_DH_IMM_RETRY: |
| 1147 | case SCSI_DH_RES_TEMP_UNAVAIL: |
| 1148 | if (pg_init_limit_reached(m, pgpath)) |
| 1149 | fail_path(pgpath); |
| 1150 | errors = 0; |
| 1151 | break; |
| 1152 | default: |
| 1153 | /* |
| 1154 | * We probably do not want to fail the path for a device |
| 1155 | * error, but this is what the old dm did. In future |
| 1156 | * patches we can do more advanced handling. |
| 1157 | */ |
| 1158 | fail_path(pgpath); |
| 1159 | } |
| 1160 | |
| 1161 | spin_lock_irqsave(&m->lock, flags); |
| 1162 | if (errors) { |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 1163 | if (pgpath == m->current_pgpath) { |
| 1164 | DMERR("Could not failover device. Error %d.", errors); |
| 1165 | m->current_pgpath = NULL; |
| 1166 | m->current_pg = NULL; |
| 1167 | } |
Kiyoshi Ueda | d0259bf | 2010-03-06 02:30:02 +0000 | [diff] [blame] | 1168 | } else if (!m->pg_init_required) |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1169 | pg->bypassed = 0; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1170 | |
Kiyoshi Ueda | d0259bf | 2010-03-06 02:30:02 +0000 | [diff] [blame] | 1171 | if (--m->pg_init_in_progress) |
| 1172 | /* Activations of other paths are still on going */ |
| 1173 | goto out; |
| 1174 | |
Hannes Reinecke | 3e9f1be | 2014-02-28 15:33:45 +0100 | [diff] [blame] | 1175 | if (m->pg_init_required) { |
| 1176 | m->pg_init_delay_retry = delay_retry; |
| 1177 | if (__pg_init_all_paths(m)) |
| 1178 | goto out; |
| 1179 | } |
| 1180 | m->queue_io = 0; |
Kiyoshi Ueda | d0259bf | 2010-03-06 02:30:02 +0000 | [diff] [blame] | 1181 | |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 1182 | /* |
| 1183 | * Wake up any thread waiting to suspend. |
| 1184 | */ |
| 1185 | wake_up(&m->pg_init_wait); |
| 1186 | |
Kiyoshi Ueda | d0259bf | 2010-03-06 02:30:02 +0000 | [diff] [blame] | 1187 | out: |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1188 | spin_unlock_irqrestore(&m->lock, flags); |
| 1189 | } |
| 1190 | |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1191 | static void activate_path(struct work_struct *work) |
| 1192 | { |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 1193 | struct pgpath *pgpath = |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1194 | container_of(work, struct pgpath, activate_path.work); |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1195 | |
Chandra Seetharaman | 3ae31f6 | 2009-10-21 09:22:46 -0700 | [diff] [blame] | 1196 | scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), |
Moger, Babu | 83c0d5d | 2010-03-06 02:29:45 +0000 | [diff] [blame] | 1197 | pg_init_done, pgpath); |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1198 | } |
| 1199 | |
Hannes Reinecke | 7e782af | 2013-07-01 15:16:26 +0200 | [diff] [blame] | 1200 | static int noretry_error(int error) |
| 1201 | { |
| 1202 | switch (error) { |
| 1203 | case -EOPNOTSUPP: |
| 1204 | case -EREMOTEIO: |
| 1205 | case -EILSEQ: |
| 1206 | case -ENODATA: |
Jun'ichi Nomura | cc9d3c3 | 2013-09-13 14:54:30 +0900 | [diff] [blame] | 1207 | case -ENOSPC: |
Hannes Reinecke | 7e782af | 2013-07-01 15:16:26 +0200 | [diff] [blame] | 1208 | return 1; |
| 1209 | } |
| 1210 | |
| 1211 | /* Anything else could be a path failure, so should be retried */ |
| 1212 | return 0; |
| 1213 | } |
| 1214 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1215 | /* |
| 1216 | * end_io handling |
| 1217 | */ |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1218 | static int do_end_io(struct multipath *m, struct request *clone, |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 1219 | int error, struct dm_mpath_io *mpio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1220 | { |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1221 | /* |
| 1222 | * We don't queue any clone request inside the multipath target |
| 1223 | * during end I/O handling, since those clone requests don't have |
| 1224 | * bio clones. If we queue them inside the multipath target, |
| 1225 | * we need to make bio clones, that requires memory allocation. |
| 1226 | * (See drivers/md/dm.c:end_clone_bio() about why the clone requests |
| 1227 | * don't have bio clones.) |
| 1228 | * Instead of queueing the clone request here, we queue the original |
| 1229 | * request into dm core, which will remake a clone request and |
| 1230 | * clone bios for it and resubmit it later. |
| 1231 | */ |
| 1232 | int r = DM_ENDIO_REQUEUE; |
Stefan Bader | 640eb3b | 2005-11-21 21:32:35 -0800 | [diff] [blame] | 1233 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1234 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1235 | if (!error && !clone->errors) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1236 | return 0; /* I/O complete */ |
| 1237 | |
Mike Snitzer | f84cb8a | 2013-09-19 12:13:58 -0400 | [diff] [blame] | 1238 | if (noretry_error(error)) { |
| 1239 | if ((clone->cmd_flags & REQ_WRITE_SAME) && |
| 1240 | !clone->q->limits.max_write_same_sectors) { |
| 1241 | struct queue_limits *limits; |
| 1242 | |
| 1243 | /* device doesn't really support WRITE SAME, disable it */ |
| 1244 | limits = dm_get_queue_limits(dm_table_get_md(m->ti->table)); |
| 1245 | limits->max_write_same_sectors = 0; |
| 1246 | } |
Mike Snitzer | 959eb4e | 2010-08-12 04:14:32 +0100 | [diff] [blame] | 1247 | return error; |
Mike Snitzer | f84cb8a | 2013-09-19 12:13:58 -0400 | [diff] [blame] | 1248 | } |
Mike Snitzer | 959eb4e | 2010-08-12 04:14:32 +0100 | [diff] [blame] | 1249 | |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1250 | if (mpio->pgpath) |
| 1251 | fail_path(mpio->pgpath); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1252 | |
Stefan Bader | 640eb3b | 2005-11-21 21:32:35 -0800 | [diff] [blame] | 1253 | spin_lock_irqsave(&m->lock, flags); |
Hannes Reinecke | 751b2a7 | 2011-01-18 10:13:12 +0100 | [diff] [blame] | 1254 | if (!m->nr_valid_paths) { |
| 1255 | if (!m->queue_if_no_path) { |
| 1256 | if (!__must_push_back(m)) |
| 1257 | r = -EIO; |
| 1258 | } else { |
| 1259 | if (error == -EBADE) |
| 1260 | r = error; |
| 1261 | } |
| 1262 | } |
Stefan Bader | 640eb3b | 2005-11-21 21:32:35 -0800 | [diff] [blame] | 1263 | spin_unlock_irqrestore(&m->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1264 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1265 | return r; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1266 | } |
| 1267 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1268 | static int multipath_end_io(struct dm_target *ti, struct request *clone, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1269 | int error, union map_info *map_context) |
| 1270 | { |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 1271 | struct multipath *m = ti->private; |
| 1272 | struct dm_mpath_io *mpio = map_context->ptr; |
Wei Yongjun | a71a261 | 2012-10-12 16:59:42 +0100 | [diff] [blame] | 1273 | struct pgpath *pgpath; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1274 | struct path_selector *ps; |
| 1275 | int r; |
| 1276 | |
Jun'ichi Nomura | 466891f | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 1277 | BUG_ON(!mpio); |
| 1278 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1279 | r = do_end_io(m, clone, error, mpio); |
Wei Yongjun | a71a261 | 2012-10-12 16:59:42 +0100 | [diff] [blame] | 1280 | pgpath = mpio->pgpath; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1281 | if (pgpath) { |
| 1282 | ps = &pgpath->pg->ps; |
| 1283 | if (ps->type->end_io) |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 1284 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1285 | } |
Jun'ichi Nomura | 466891f | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 1286 | clear_mapinfo(m, map_context); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1287 | |
| 1288 | return r; |
| 1289 | } |
| 1290 | |
| 1291 | /* |
| 1292 | * Suspend can't complete until all the I/O is processed so if |
Alasdair G Kergon | 436d410 | 2005-07-12 15:53:03 -0700 | [diff] [blame] | 1293 | * the last path fails we must error any remaining I/O. |
| 1294 | * Note that if the freeze_bdev fails while suspending, the |
| 1295 | * queue_if_no_path state is lost - userspace should reset it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1296 | */ |
| 1297 | static void multipath_presuspend(struct dm_target *ti) |
| 1298 | { |
| 1299 | struct multipath *m = (struct multipath *) ti->private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1300 | |
Alasdair G Kergon | 485ef69 | 2005-09-27 21:45:45 -0700 | [diff] [blame] | 1301 | queue_if_no_path(m, 0, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1302 | } |
| 1303 | |
Kiyoshi Ueda | 6df400a | 2009-12-10 23:52:19 +0000 | [diff] [blame] | 1304 | static void multipath_postsuspend(struct dm_target *ti) |
| 1305 | { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1306 | struct multipath *m = ti->private; |
| 1307 | |
| 1308 | mutex_lock(&m->work_mutex); |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 1309 | flush_multipath_work(m); |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1310 | mutex_unlock(&m->work_mutex); |
Kiyoshi Ueda | 6df400a | 2009-12-10 23:52:19 +0000 | [diff] [blame] | 1311 | } |
| 1312 | |
Alasdair G Kergon | 436d410 | 2005-07-12 15:53:03 -0700 | [diff] [blame] | 1313 | /* |
| 1314 | * Restore the queue_if_no_path setting. |
| 1315 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1316 | static void multipath_resume(struct dm_target *ti) |
| 1317 | { |
| 1318 | struct multipath *m = (struct multipath *) ti->private; |
| 1319 | unsigned long flags; |
| 1320 | |
| 1321 | spin_lock_irqsave(&m->lock, flags); |
Alasdair G Kergon | 436d410 | 2005-07-12 15:53:03 -0700 | [diff] [blame] | 1322 | m->queue_if_no_path = m->saved_queue_if_no_path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1323 | spin_unlock_irqrestore(&m->lock, flags); |
| 1324 | } |
| 1325 | |
| 1326 | /* |
| 1327 | * Info output has the following format: |
| 1328 | * num_multipath_feature_args [multipath_feature_args]* |
| 1329 | * num_handler_status_args [handler_status_args]* |
| 1330 | * num_groups init_group_number |
| 1331 | * [A|D|E num_ps_status_args [ps_status_args]* |
| 1332 | * num_paths num_selector_args |
| 1333 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ |
| 1334 | * |
| 1335 | * Table output has the following format (identical to the constructor string): |
| 1336 | * num_feature_args [features_args]* |
| 1337 | * num_handler_args hw_handler [hw_handler_args]* |
| 1338 | * num_groups init_group_number |
| 1339 | * [priority selector-name num_ps_args [ps_args]* |
| 1340 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ |
| 1341 | */ |
Mikulas Patocka | fd7c092 | 2013-03-01 22:45:44 +0000 | [diff] [blame] | 1342 | static void multipath_status(struct dm_target *ti, status_type_t type, |
| 1343 | unsigned status_flags, char *result, unsigned maxlen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1344 | { |
| 1345 | int sz = 0; |
| 1346 | unsigned long flags; |
| 1347 | struct multipath *m = (struct multipath *) ti->private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1348 | struct priority_group *pg; |
| 1349 | struct pgpath *p; |
| 1350 | unsigned pg_num; |
| 1351 | char state; |
| 1352 | |
| 1353 | spin_lock_irqsave(&m->lock, flags); |
| 1354 | |
| 1355 | /* Features */ |
| 1356 | if (type == STATUSTYPE_INFO) |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 1357 | DMEMIT("2 %u %u ", m->queue_io, m->pg_init_count); |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 1358 | else { |
| 1359 | DMEMIT("%u ", m->queue_if_no_path + |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1360 | (m->pg_init_retries > 0) * 2 + |
Mike Snitzer | a58a935 | 2012-07-27 15:08:04 +0100 | [diff] [blame] | 1361 | (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 + |
| 1362 | m->retain_attached_hw_handler); |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 1363 | if (m->queue_if_no_path) |
| 1364 | DMEMIT("queue_if_no_path "); |
| 1365 | if (m->pg_init_retries) |
| 1366 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1367 | if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) |
| 1368 | DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs); |
Mike Snitzer | a58a935 | 2012-07-27 15:08:04 +0100 | [diff] [blame] | 1369 | if (m->retain_attached_hw_handler) |
| 1370 | DMEMIT("retain_attached_hw_handler "); |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 1371 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1372 | |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1373 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1374 | DMEMIT("0 "); |
| 1375 | else |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1376 | DMEMIT("1 %s ", m->hw_handler_name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1377 | |
| 1378 | DMEMIT("%u ", m->nr_priority_groups); |
| 1379 | |
| 1380 | if (m->next_pg) |
| 1381 | pg_num = m->next_pg->pg_num; |
| 1382 | else if (m->current_pg) |
| 1383 | pg_num = m->current_pg->pg_num; |
| 1384 | else |
Mike Snitzer | a490a07 | 2011-03-24 13:54:33 +0000 | [diff] [blame] | 1385 | pg_num = (m->nr_priority_groups ? 1 : 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1386 | |
| 1387 | DMEMIT("%u ", pg_num); |
| 1388 | |
| 1389 | switch (type) { |
| 1390 | case STATUSTYPE_INFO: |
| 1391 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1392 | if (pg->bypassed) |
| 1393 | state = 'D'; /* Disabled */ |
| 1394 | else if (pg == m->current_pg) |
| 1395 | state = 'A'; /* Currently Active */ |
| 1396 | else |
| 1397 | state = 'E'; /* Enabled */ |
| 1398 | |
| 1399 | DMEMIT("%c ", state); |
| 1400 | |
| 1401 | if (pg->ps.type->status) |
| 1402 | sz += pg->ps.type->status(&pg->ps, NULL, type, |
| 1403 | result + sz, |
| 1404 | maxlen - sz); |
| 1405 | else |
| 1406 | DMEMIT("0 "); |
| 1407 | |
| 1408 | DMEMIT("%u %u ", pg->nr_pgpaths, |
| 1409 | pg->ps.type->info_args); |
| 1410 | |
| 1411 | list_for_each_entry(p, &pg->pgpaths, list) { |
| 1412 | DMEMIT("%s %s %u ", p->path.dev->name, |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 1413 | p->is_active ? "A" : "F", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1414 | p->fail_count); |
| 1415 | if (pg->ps.type->status) |
| 1416 | sz += pg->ps.type->status(&pg->ps, |
| 1417 | &p->path, type, result + sz, |
| 1418 | maxlen - sz); |
| 1419 | } |
| 1420 | } |
| 1421 | break; |
| 1422 | |
| 1423 | case STATUSTYPE_TABLE: |
| 1424 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1425 | DMEMIT("%s ", pg->ps.type->name); |
| 1426 | |
| 1427 | if (pg->ps.type->status) |
| 1428 | sz += pg->ps.type->status(&pg->ps, NULL, type, |
| 1429 | result + sz, |
| 1430 | maxlen - sz); |
| 1431 | else |
| 1432 | DMEMIT("0 "); |
| 1433 | |
| 1434 | DMEMIT("%u %u ", pg->nr_pgpaths, |
| 1435 | pg->ps.type->table_args); |
| 1436 | |
| 1437 | list_for_each_entry(p, &pg->pgpaths, list) { |
| 1438 | DMEMIT("%s ", p->path.dev->name); |
| 1439 | if (pg->ps.type->status) |
| 1440 | sz += pg->ps.type->status(&pg->ps, |
| 1441 | &p->path, type, result + sz, |
| 1442 | maxlen - sz); |
| 1443 | } |
| 1444 | } |
| 1445 | break; |
| 1446 | } |
| 1447 | |
| 1448 | spin_unlock_irqrestore(&m->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1449 | } |
| 1450 | |
| 1451 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) |
| 1452 | { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1453 | int r = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1454 | struct dm_dev *dev; |
| 1455 | struct multipath *m = (struct multipath *) ti->private; |
| 1456 | action_fn action; |
| 1457 | |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1458 | mutex_lock(&m->work_mutex); |
| 1459 | |
Kiyoshi Ueda | c2f3d24 | 2009-12-10 23:52:27 +0000 | [diff] [blame] | 1460 | if (dm_suspended(ti)) { |
| 1461 | r = -EBUSY; |
| 1462 | goto out; |
| 1463 | } |
| 1464 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | if (argc == 1) { |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1466 | if (!strcasecmp(argv[0], "queue_if_no_path")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1467 | r = queue_if_no_path(m, 1, 0); |
| 1468 | goto out; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1469 | } else if (!strcasecmp(argv[0], "fail_if_no_path")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1470 | r = queue_if_no_path(m, 0, 0); |
| 1471 | goto out; |
| 1472 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1473 | } |
| 1474 | |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1475 | if (argc != 2) { |
| 1476 | DMWARN("Unrecognised multipath message received."); |
| 1477 | goto out; |
| 1478 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1479 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1480 | if (!strcasecmp(argv[0], "disable_group")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1481 | r = bypass_pg_num(m, argv[1], 1); |
| 1482 | goto out; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1483 | } else if (!strcasecmp(argv[0], "enable_group")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1484 | r = bypass_pg_num(m, argv[1], 0); |
| 1485 | goto out; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1486 | } else if (!strcasecmp(argv[0], "switch_group")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1487 | r = switch_pg_num(m, argv[1]); |
| 1488 | goto out; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1489 | } else if (!strcasecmp(argv[0], "reinstate_path")) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1490 | action = reinstate_path; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1491 | else if (!strcasecmp(argv[0], "fail_path")) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1492 | action = fail_path; |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1493 | else { |
| 1494 | DMWARN("Unrecognised multipath message received."); |
| 1495 | goto out; |
| 1496 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1497 | |
Nikanth Karthikesan | 8215d6e | 2010-03-06 02:32:27 +0000 | [diff] [blame] | 1498 | r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1499 | if (r) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 1500 | DMWARN("message: error getting device %s", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1501 | argv[1]); |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1502 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1503 | } |
| 1504 | |
| 1505 | r = action_dev(m, dev, action); |
| 1506 | |
| 1507 | dm_put_device(ti, dev); |
| 1508 | |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1509 | out: |
| 1510 | mutex_unlock(&m->work_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1511 | return r; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1512 | } |
| 1513 | |
Al Viro | 647b3d0 | 2007-08-28 22:15:59 -0400 | [diff] [blame] | 1514 | static int multipath_ioctl(struct dm_target *ti, unsigned int cmd, |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1515 | unsigned long arg) |
| 1516 | { |
Mikulas Patocka | 3599165 | 2012-06-03 00:29:58 +0100 | [diff] [blame] | 1517 | struct multipath *m = ti->private; |
Mike Snitzer | 7ba10aa | 2012-09-26 23:45:41 +0100 | [diff] [blame] | 1518 | struct pgpath *pgpath; |
Mikulas Patocka | 3599165 | 2012-06-03 00:29:58 +0100 | [diff] [blame] | 1519 | struct block_device *bdev; |
| 1520 | fmode_t mode; |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1521 | unsigned long flags; |
Mikulas Patocka | 3599165 | 2012-06-03 00:29:58 +0100 | [diff] [blame] | 1522 | int r; |
| 1523 | |
Mikulas Patocka | 3599165 | 2012-06-03 00:29:58 +0100 | [diff] [blame] | 1524 | bdev = NULL; |
| 1525 | mode = 0; |
| 1526 | r = 0; |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1527 | |
| 1528 | spin_lock_irqsave(&m->lock, flags); |
| 1529 | |
| 1530 | if (!m->current_pgpath) |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 1531 | __choose_pgpath(m, 0); |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1532 | |
Mike Snitzer | 7ba10aa | 2012-09-26 23:45:41 +0100 | [diff] [blame] | 1533 | pgpath = m->current_pgpath; |
| 1534 | |
| 1535 | if (pgpath) { |
| 1536 | bdev = pgpath->path.dev->bdev; |
| 1537 | mode = pgpath->path.dev->mode; |
Milan Broz | e90dae1 | 2006-10-03 01:15:22 -0700 | [diff] [blame] | 1538 | } |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1539 | |
Mike Snitzer | 7ba10aa | 2012-09-26 23:45:41 +0100 | [diff] [blame] | 1540 | if ((pgpath && m->queue_io) || (!pgpath && m->queue_if_no_path)) |
Hannes Reinecke | 6c182cd | 2013-07-10 23:41:15 +0100 | [diff] [blame] | 1541 | r = -ENOTCONN; |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1542 | else if (!bdev) |
| 1543 | r = -EIO; |
| 1544 | |
| 1545 | spin_unlock_irqrestore(&m->lock, flags); |
| 1546 | |
Paolo Bonzini | ec8013b | 2012-01-12 16:01:29 +0100 | [diff] [blame] | 1547 | /* |
| 1548 | * Only pass ioctls through if the device sizes match exactly. |
| 1549 | */ |
Hannes Reinecke | a1989b3 | 2014-02-26 10:07:04 +0100 | [diff] [blame] | 1550 | if (!bdev || ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT) { |
| 1551 | int err = scsi_verify_blk_ioctl(NULL, cmd); |
| 1552 | if (err) |
| 1553 | r = err; |
| 1554 | } |
Paolo Bonzini | ec8013b | 2012-01-12 16:01:29 +0100 | [diff] [blame] | 1555 | |
Hannes Reinecke | 3e9f1be | 2014-02-28 15:33:45 +0100 | [diff] [blame] | 1556 | if (r == -ENOTCONN && !fatal_signal_pending(current)) { |
| 1557 | spin_lock_irqsave(&m->lock, flags); |
| 1558 | if (!m->current_pg) { |
| 1559 | /* Path status changed, redo selection */ |
| 1560 | __choose_pgpath(m, 0); |
| 1561 | } |
| 1562 | if (m->pg_init_required) |
| 1563 | __pg_init_all_paths(m); |
| 1564 | spin_unlock_irqrestore(&m->lock, flags); |
| 1565 | dm_table_run_md_queue_async(m->ti->table); |
| 1566 | } |
Mikulas Patocka | 3599165 | 2012-06-03 00:29:58 +0100 | [diff] [blame] | 1567 | |
Al Viro | 633a08b | 2007-08-29 20:34:12 -0400 | [diff] [blame] | 1568 | return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg); |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1569 | } |
| 1570 | |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 1571 | static int multipath_iterate_devices(struct dm_target *ti, |
| 1572 | iterate_devices_callout_fn fn, void *data) |
| 1573 | { |
| 1574 | struct multipath *m = ti->private; |
| 1575 | struct priority_group *pg; |
| 1576 | struct pgpath *p; |
| 1577 | int ret = 0; |
| 1578 | |
| 1579 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1580 | list_for_each_entry(p, &pg->pgpaths, list) { |
Mike Snitzer | 5dea271 | 2009-07-23 20:30:42 +0100 | [diff] [blame] | 1581 | ret = fn(ti, p->path.dev, ti->begin, ti->len, data); |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 1582 | if (ret) |
| 1583 | goto out; |
| 1584 | } |
| 1585 | } |
| 1586 | |
| 1587 | out: |
| 1588 | return ret; |
| 1589 | } |
| 1590 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1591 | static int __pgpath_busy(struct pgpath *pgpath) |
| 1592 | { |
| 1593 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); |
| 1594 | |
| 1595 | return dm_underlying_device_busy(q); |
| 1596 | } |
| 1597 | |
| 1598 | /* |
| 1599 | * We return "busy", only when we can map I/Os but underlying devices |
| 1600 | * are busy (so even if we map I/Os now, the I/Os will wait on |
| 1601 | * the underlying queue). |
| 1602 | * In other words, if we want to kill I/Os or queue them inside us |
| 1603 | * due to map unavailability, we don't return "busy". Otherwise, |
| 1604 | * dm core won't give us the I/Os and we can't do what we want. |
| 1605 | */ |
| 1606 | static int multipath_busy(struct dm_target *ti) |
| 1607 | { |
| 1608 | int busy = 0, has_active = 0; |
| 1609 | struct multipath *m = ti->private; |
| 1610 | struct priority_group *pg; |
| 1611 | struct pgpath *pgpath; |
| 1612 | unsigned long flags; |
| 1613 | |
| 1614 | spin_lock_irqsave(&m->lock, flags); |
| 1615 | |
Hannes Reinecke | b63349a | 2013-10-01 11:49:56 +0200 | [diff] [blame] | 1616 | /* pg_init in progress, requeue until done */ |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 1617 | if (!pg_ready(m)) { |
Hannes Reinecke | b63349a | 2013-10-01 11:49:56 +0200 | [diff] [blame] | 1618 | busy = 1; |
| 1619 | goto out; |
| 1620 | } |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1621 | /* Guess which priority_group will be used at next mapping time */ |
| 1622 | if (unlikely(!m->current_pgpath && m->next_pg)) |
| 1623 | pg = m->next_pg; |
| 1624 | else if (likely(m->current_pg)) |
| 1625 | pg = m->current_pg; |
| 1626 | else |
| 1627 | /* |
| 1628 | * We don't know which pg will be used at next mapping time. |
| 1629 | * We don't call __choose_pgpath() here to avoid to trigger |
| 1630 | * pg_init just by busy checking. |
| 1631 | * So we don't know whether underlying devices we will be using |
| 1632 | * at next mapping time are busy or not. Just try mapping. |
| 1633 | */ |
| 1634 | goto out; |
| 1635 | |
| 1636 | /* |
| 1637 | * If there is one non-busy active path at least, the path selector |
| 1638 | * will be able to select it. So we consider such a pg as not busy. |
| 1639 | */ |
| 1640 | busy = 1; |
| 1641 | list_for_each_entry(pgpath, &pg->pgpaths, list) |
| 1642 | if (pgpath->is_active) { |
| 1643 | has_active = 1; |
| 1644 | |
| 1645 | if (!__pgpath_busy(pgpath)) { |
| 1646 | busy = 0; |
| 1647 | break; |
| 1648 | } |
| 1649 | } |
| 1650 | |
| 1651 | if (!has_active) |
| 1652 | /* |
| 1653 | * No active path in this pg, so this pg won't be used and |
| 1654 | * the current_pg will be changed at next mapping time. |
| 1655 | * We need to try mapping to determine it. |
| 1656 | */ |
| 1657 | busy = 0; |
| 1658 | |
| 1659 | out: |
| 1660 | spin_unlock_irqrestore(&m->lock, flags); |
| 1661 | |
| 1662 | return busy; |
| 1663 | } |
| 1664 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1665 | /*----------------------------------------------------------------- |
| 1666 | * Module setup |
| 1667 | *---------------------------------------------------------------*/ |
| 1668 | static struct target_type multipath_target = { |
| 1669 | .name = "multipath", |
Hannes Reinecke | e809917 | 2014-02-28 15:33:44 +0100 | [diff] [blame] | 1670 | .version = {1, 7, 0}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1671 | .module = THIS_MODULE, |
| 1672 | .ctr = multipath_ctr, |
| 1673 | .dtr = multipath_dtr, |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1674 | .map_rq = multipath_map, |
| 1675 | .rq_end_io = multipath_end_io, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1676 | .presuspend = multipath_presuspend, |
Kiyoshi Ueda | 6df400a | 2009-12-10 23:52:19 +0000 | [diff] [blame] | 1677 | .postsuspend = multipath_postsuspend, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1678 | .resume = multipath_resume, |
| 1679 | .status = multipath_status, |
| 1680 | .message = multipath_message, |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1681 | .ioctl = multipath_ioctl, |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 1682 | .iterate_devices = multipath_iterate_devices, |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1683 | .busy = multipath_busy, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1684 | }; |
| 1685 | |
| 1686 | static int __init dm_multipath_init(void) |
| 1687 | { |
| 1688 | int r; |
| 1689 | |
| 1690 | /* allocate a slab for the dm_ios */ |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 1691 | _mpio_cache = KMEM_CACHE(dm_mpath_io, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1692 | if (!_mpio_cache) |
| 1693 | return -ENOMEM; |
| 1694 | |
| 1695 | r = dm_register_target(&multipath_target); |
| 1696 | if (r < 0) { |
Alasdair G Kergon | 0cd3312 | 2007-07-12 17:27:01 +0100 | [diff] [blame] | 1697 | DMERR("register failed %d", r); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1698 | kmem_cache_destroy(_mpio_cache); |
| 1699 | return -EINVAL; |
| 1700 | } |
| 1701 | |
Tejun Heo | 4d4d66a | 2011-01-13 19:59:57 +0000 | [diff] [blame] | 1702 | kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0); |
Alasdair G Kergon | c557308 | 2005-05-05 16:16:07 -0700 | [diff] [blame] | 1703 | if (!kmultipathd) { |
Alasdair G Kergon | 0cd3312 | 2007-07-12 17:27:01 +0100 | [diff] [blame] | 1704 | DMERR("failed to create workqueue kmpathd"); |
Alasdair G Kergon | c557308 | 2005-05-05 16:16:07 -0700 | [diff] [blame] | 1705 | dm_unregister_target(&multipath_target); |
| 1706 | kmem_cache_destroy(_mpio_cache); |
| 1707 | return -ENOMEM; |
| 1708 | } |
| 1709 | |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1710 | /* |
| 1711 | * A separate workqueue is used to handle the device handlers |
| 1712 | * to avoid overloading existing workqueue. Overloading the |
| 1713 | * old workqueue would also create a bottleneck in the |
| 1714 | * path of the storage hardware device activation. |
| 1715 | */ |
Tejun Heo | 4d4d66a | 2011-01-13 19:59:57 +0000 | [diff] [blame] | 1716 | kmpath_handlerd = alloc_ordered_workqueue("kmpath_handlerd", |
| 1717 | WQ_MEM_RECLAIM); |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1718 | if (!kmpath_handlerd) { |
| 1719 | DMERR("failed to create workqueue kmpath_handlerd"); |
| 1720 | destroy_workqueue(kmultipathd); |
| 1721 | dm_unregister_target(&multipath_target); |
| 1722 | kmem_cache_destroy(_mpio_cache); |
| 1723 | return -ENOMEM; |
| 1724 | } |
| 1725 | |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 1726 | DMINFO("version %u.%u.%u loaded", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1727 | multipath_target.version[0], multipath_target.version[1], |
| 1728 | multipath_target.version[2]); |
| 1729 | |
| 1730 | return r; |
| 1731 | } |
| 1732 | |
| 1733 | static void __exit dm_multipath_exit(void) |
| 1734 | { |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1735 | destroy_workqueue(kmpath_handlerd); |
Alasdair G Kergon | c557308 | 2005-05-05 16:16:07 -0700 | [diff] [blame] | 1736 | destroy_workqueue(kmultipathd); |
| 1737 | |
Mikulas Patocka | 10d3bd0 | 2009-01-06 03:04:58 +0000 | [diff] [blame] | 1738 | dm_unregister_target(&multipath_target); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1739 | kmem_cache_destroy(_mpio_cache); |
| 1740 | } |
| 1741 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1742 | module_init(dm_multipath_init); |
| 1743 | module_exit(dm_multipath_exit); |
| 1744 | |
| 1745 | MODULE_DESCRIPTION(DM_NAME " multipath target"); |
| 1746 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); |
| 1747 | MODULE_LICENSE("GPL"); |