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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include "dm-path-selector.h" |
Mike Anderson | b15546f | 2007-10-19 22:48:02 +0100 | [diff] [blame] | 11 | #include "dm-uevent.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | |
| 13 | #include <linux/ctype.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/mempool.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/pagemap.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/time.h> |
| 20 | #include <linux/workqueue.h> |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 21 | #include <scsi/scsi_dh.h> |
Arun Sharma | 6006349 | 2011-07-26 16:09:06 -0700 | [diff] [blame] | 22 | #include <linux/atomic.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 24 | #define DM_MSG_PREFIX "multipath" |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 25 | #define DM_PG_INIT_DELAY_MSECS 2000 |
| 26 | #define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | |
| 28 | /* Path properties */ |
| 29 | struct pgpath { |
| 30 | struct list_head list; |
| 31 | |
| 32 | struct priority_group *pg; /* Owning PG */ |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 33 | unsigned is_active; /* Path status */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | unsigned fail_count; /* Cumulative failure count */ |
| 35 | |
Josef "Jeff" Sipek | c922d5f | 2006-12-08 02:36:33 -0800 | [diff] [blame] | 36 | struct dm_path path; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 37 | struct delayed_work activate_path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | }; |
| 39 | |
| 40 | #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path) |
| 41 | |
| 42 | /* |
| 43 | * Paths are grouped into Priority Groups and numbered from 1 upwards. |
| 44 | * Each has a path selector which controls which path gets used. |
| 45 | */ |
| 46 | struct priority_group { |
| 47 | struct list_head list; |
| 48 | |
| 49 | struct multipath *m; /* Owning multipath instance */ |
| 50 | struct path_selector ps; |
| 51 | |
| 52 | unsigned pg_num; /* Reference number */ |
| 53 | unsigned bypassed; /* Temporarily bypass this PG? */ |
| 54 | |
| 55 | unsigned nr_pgpaths; /* Number of paths in PG */ |
| 56 | struct list_head pgpaths; |
| 57 | }; |
| 58 | |
| 59 | /* Multipath context */ |
| 60 | struct multipath { |
| 61 | struct list_head list; |
| 62 | struct dm_target *ti; |
| 63 | |
| 64 | spinlock_t lock; |
| 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | unsigned nr_priority_groups; |
| 70 | struct list_head priority_groups; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 71 | |
| 72 | wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */ |
| 73 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | unsigned pg_init_required; /* pg_init needs calling? */ |
Alasdair G Kergon | c3cd4f6 | 2005-07-12 15:53:04 -0700 | [diff] [blame] | 75 | unsigned pg_init_in_progress; /* Only one pg_init allowed at once */ |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 76 | unsigned pg_init_delay_retry; /* Delay pg_init retry? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
| 78 | unsigned nr_valid_paths; /* Total number of usable paths */ |
| 79 | struct pgpath *current_pgpath; |
| 80 | struct priority_group *current_pg; |
| 81 | struct priority_group *next_pg; /* Switch to this PG if set */ |
| 82 | unsigned repeat_count; /* I/Os left before calling PS again */ |
| 83 | |
| 84 | unsigned queue_io; /* Must we queue all I/O? */ |
| 85 | unsigned queue_if_no_path; /* Queue I/O if last path fails? */ |
Alasdair G Kergon | 436d410 | 2005-07-12 15:53:03 -0700 | [diff] [blame] | 86 | unsigned saved_queue_if_no_path;/* Saved state during suspension */ |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 87 | unsigned pg_init_retries; /* Number of times to retry pg_init */ |
| 88 | unsigned pg_init_count; /* Number of times pg_init called */ |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 89 | unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
| 91 | struct work_struct process_queued_ios; |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 92 | struct list_head queued_ios; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | unsigned queue_size; |
| 94 | |
| 95 | struct work_struct trigger_event; |
| 96 | |
| 97 | /* |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 98 | * 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] | 99 | * can resubmit bios on error. |
| 100 | */ |
| 101 | mempool_t *mpio_pool; |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 102 | |
| 103 | struct mutex work_mutex; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | }; |
| 105 | |
| 106 | /* |
| 107 | * Context information attached to each bio we process. |
| 108 | */ |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 109 | struct dm_mpath_io { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | struct pgpath *pgpath; |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 111 | size_t nr_bytes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | }; |
| 113 | |
| 114 | typedef int (*action_fn) (struct pgpath *pgpath); |
| 115 | |
| 116 | #define MIN_IOS 256 /* Mempool size */ |
| 117 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 118 | static struct kmem_cache *_mpio_cache; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 120 | static struct workqueue_struct *kmultipathd, *kmpath_handlerd; |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 121 | static void process_queued_ios(struct work_struct *work); |
| 122 | static void trigger_event(struct work_struct *work); |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 123 | static void activate_path(struct work_struct *work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | |
| 125 | |
| 126 | /*----------------------------------------------- |
| 127 | * Allocation routines |
| 128 | *-----------------------------------------------*/ |
| 129 | |
| 130 | static struct pgpath *alloc_pgpath(void) |
| 131 | { |
Micha³ Miros³aw | e69fae5 | 2006-10-03 01:15:34 -0700 | [diff] [blame] | 132 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
Mike Anderson | 224cb3e | 2008-08-29 09:36:09 +0200 | [diff] [blame] | 134 | if (pgpath) { |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 135 | pgpath->is_active = 1; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 136 | INIT_DELAYED_WORK(&pgpath->activate_path, activate_path); |
Mike Anderson | 224cb3e | 2008-08-29 09:36:09 +0200 | [diff] [blame] | 137 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | |
| 139 | return pgpath; |
| 140 | } |
| 141 | |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 142 | static void free_pgpath(struct pgpath *pgpath) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | { |
| 144 | kfree(pgpath); |
| 145 | } |
| 146 | |
| 147 | static struct priority_group *alloc_priority_group(void) |
| 148 | { |
| 149 | struct priority_group *pg; |
| 150 | |
Micha³ Miros³aw | e69fae5 | 2006-10-03 01:15:34 -0700 | [diff] [blame] | 151 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | |
Micha³ Miros³aw | e69fae5 | 2006-10-03 01:15:34 -0700 | [diff] [blame] | 153 | if (pg) |
| 154 | INIT_LIST_HEAD(&pg->pgpaths); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | |
| 156 | return pg; |
| 157 | } |
| 158 | |
| 159 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) |
| 160 | { |
| 161 | struct pgpath *pgpath, *tmp; |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 162 | struct multipath *m = ti->private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | |
| 164 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { |
| 165 | list_del(&pgpath->list); |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 166 | if (m->hw_handler_name) |
| 167 | scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | dm_put_device(ti, pgpath->path.dev); |
| 169 | free_pgpath(pgpath); |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | static void free_priority_group(struct priority_group *pg, |
| 174 | struct dm_target *ti) |
| 175 | { |
| 176 | struct path_selector *ps = &pg->ps; |
| 177 | |
| 178 | if (ps->type) { |
| 179 | ps->type->destroy(ps); |
| 180 | dm_put_path_selector(ps->type); |
| 181 | } |
| 182 | |
| 183 | free_pgpaths(&pg->pgpaths, ti); |
| 184 | kfree(pg); |
| 185 | } |
| 186 | |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 187 | static struct multipath *alloc_multipath(struct dm_target *ti) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | { |
| 189 | struct multipath *m; |
| 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); |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 194 | INIT_LIST_HEAD(&m->queued_ios); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | spin_lock_init(&m->lock); |
| 196 | m->queue_io = 1; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 197 | m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 198 | INIT_WORK(&m->process_queued_ios, process_queued_ios); |
| 199 | INIT_WORK(&m->trigger_event, trigger_event); |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 200 | init_waitqueue_head(&m->pg_init_wait); |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 201 | mutex_init(&m->work_mutex); |
Matthew Dobson | 93d2341 | 2006-03-26 01:37:50 -0800 | [diff] [blame] | 202 | m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | if (!m->mpio_pool) { |
| 204 | kfree(m); |
| 205 | return NULL; |
| 206 | } |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 207 | m->ti = ti; |
| 208 | ti->private = m; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | } |
| 210 | |
| 211 | return m; |
| 212 | } |
| 213 | |
| 214 | static void free_multipath(struct multipath *m) |
| 215 | { |
| 216 | struct priority_group *pg, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | |
| 218 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { |
| 219 | list_del(&pg->list); |
| 220 | free_priority_group(pg, m->ti); |
| 221 | } |
| 222 | |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 223 | kfree(m->hw_handler_name); |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 224 | kfree(m->hw_handler_params); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | mempool_destroy(m->mpio_pool); |
| 226 | kfree(m); |
| 227 | } |
| 228 | |
| 229 | |
| 230 | /*----------------------------------------------- |
| 231 | * Path selection |
| 232 | *-----------------------------------------------*/ |
| 233 | |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 234 | static void __pg_init_all_paths(struct multipath *m) |
| 235 | { |
| 236 | struct pgpath *pgpath; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 237 | unsigned long pg_init_delay = 0; |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 238 | |
| 239 | m->pg_init_count++; |
| 240 | m->pg_init_required = 0; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 241 | if (m->pg_init_delay_retry) |
| 242 | pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ? |
| 243 | m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS); |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 244 | list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) { |
| 245 | /* Skip failed paths */ |
| 246 | if (!pgpath->is_active) |
| 247 | continue; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 248 | if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path, |
| 249 | pg_init_delay)) |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 250 | m->pg_init_in_progress++; |
| 251 | } |
| 252 | } |
| 253 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | static void __switch_pg(struct multipath *m, struct pgpath *pgpath) |
| 255 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | m->current_pg = pgpath->pg; |
| 257 | |
| 258 | /* 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] | 259 | if (m->hw_handler_name) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | m->pg_init_required = 1; |
| 261 | m->queue_io = 1; |
| 262 | } else { |
| 263 | m->pg_init_required = 0; |
| 264 | m->queue_io = 0; |
| 265 | } |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 266 | |
| 267 | m->pg_init_count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | } |
| 269 | |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 270 | static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg, |
| 271 | size_t nr_bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | { |
Josef "Jeff" Sipek | c922d5f | 2006-12-08 02:36:33 -0800 | [diff] [blame] | 273 | struct dm_path *path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 275 | 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] | 276 | if (!path) |
| 277 | return -ENXIO; |
| 278 | |
| 279 | m->current_pgpath = path_to_pgpath(path); |
| 280 | |
| 281 | if (m->current_pg != pg) |
| 282 | __switch_pg(m, m->current_pgpath); |
| 283 | |
| 284 | return 0; |
| 285 | } |
| 286 | |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 287 | static void __choose_pgpath(struct multipath *m, size_t nr_bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | { |
| 289 | struct priority_group *pg; |
| 290 | unsigned bypassed = 1; |
| 291 | |
| 292 | if (!m->nr_valid_paths) |
| 293 | goto failed; |
| 294 | |
| 295 | /* Were we instructed to switch PG? */ |
| 296 | if (m->next_pg) { |
| 297 | pg = m->next_pg; |
| 298 | m->next_pg = NULL; |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 299 | if (!__choose_path_in_pg(m, pg, nr_bytes)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | return; |
| 301 | } |
| 302 | |
| 303 | /* Don't change PG until it has no remaining paths */ |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 304 | 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] | 305 | return; |
| 306 | |
| 307 | /* |
| 308 | * Loop through priority groups until we find a valid path. |
| 309 | * First time we skip PGs marked 'bypassed'. |
| 310 | * Second time we only try the ones we skipped. |
| 311 | */ |
| 312 | do { |
| 313 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 314 | if (pg->bypassed == bypassed) |
| 315 | continue; |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 316 | if (!__choose_path_in_pg(m, pg, nr_bytes)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | return; |
| 318 | } |
| 319 | } while (bypassed--); |
| 320 | |
| 321 | failed: |
| 322 | m->current_pgpath = NULL; |
| 323 | m->current_pg = NULL; |
| 324 | } |
| 325 | |
Kiyoshi Ueda | 45e1572 | 2006-12-08 02:41:10 -0800 | [diff] [blame] | 326 | /* |
| 327 | * Check whether bios must be queued in the device-mapper core rather |
| 328 | * than here in the target. |
| 329 | * |
| 330 | * m->lock must be held on entry. |
| 331 | * |
| 332 | * If m->queue_if_no_path and m->saved_queue_if_no_path hold the |
| 333 | * same value then we are not between multipath_presuspend() |
| 334 | * and multipath_resume() calls and we have no need to check |
| 335 | * for the DMF_NOFLUSH_SUSPENDING flag. |
| 336 | */ |
| 337 | static int __must_push_back(struct multipath *m) |
| 338 | { |
| 339 | return (m->queue_if_no_path != m->saved_queue_if_no_path && |
| 340 | dm_noflush_suspending(m->ti)); |
| 341 | } |
| 342 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 343 | static int map_io(struct multipath *m, struct request *clone, |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 344 | struct dm_mpath_io *mpio, unsigned was_queued) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | { |
Kiyoshi Ueda | d2a7ad2 | 2006-12-08 02:41:06 -0800 | [diff] [blame] | 346 | int r = DM_MAPIO_REMAPPED; |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 347 | size_t nr_bytes = blk_rq_bytes(clone); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | unsigned long flags; |
| 349 | struct pgpath *pgpath; |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 350 | struct block_device *bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | |
| 352 | spin_lock_irqsave(&m->lock, flags); |
| 353 | |
| 354 | /* Do we need to select a new pgpath? */ |
| 355 | if (!m->current_pgpath || |
| 356 | (!m->queue_io && (m->repeat_count && --m->repeat_count == 0))) |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 357 | __choose_pgpath(m, nr_bytes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | |
| 359 | pgpath = m->current_pgpath; |
| 360 | |
| 361 | if (was_queued) |
| 362 | m->queue_size--; |
| 363 | |
| 364 | if ((pgpath && m->queue_io) || |
Alasdair G Kergon | 436d410 | 2005-07-12 15:53:03 -0700 | [diff] [blame] | 365 | (!pgpath && m->queue_if_no_path)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | /* Queue for the daemon to resubmit */ |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 367 | list_add_tail(&clone->queuelist, &m->queued_ios); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | m->queue_size++; |
Alasdair G Kergon | c3cd4f6 | 2005-07-12 15:53:04 -0700 | [diff] [blame] | 369 | if ((m->pg_init_required && !m->pg_init_in_progress) || |
| 370 | !m->queue_io) |
Alasdair G Kergon | c557308 | 2005-05-05 16:16:07 -0700 | [diff] [blame] | 371 | queue_work(kmultipathd, &m->process_queued_ios); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | pgpath = NULL; |
Kiyoshi Ueda | d2a7ad2 | 2006-12-08 02:41:06 -0800 | [diff] [blame] | 373 | r = DM_MAPIO_SUBMITTED; |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 374 | } else if (pgpath) { |
| 375 | bdev = pgpath->path.dev->bdev; |
| 376 | clone->q = bdev_get_queue(bdev); |
| 377 | clone->rq_disk = bdev->bd_disk; |
| 378 | } else if (__must_push_back(m)) |
Kiyoshi Ueda | 45e1572 | 2006-12-08 02:41:10 -0800 | [diff] [blame] | 379 | r = DM_MAPIO_REQUEUE; |
| 380 | else |
| 381 | r = -EIO; /* Failed */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | |
| 383 | mpio->pgpath = pgpath; |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 384 | mpio->nr_bytes = nr_bytes; |
| 385 | |
| 386 | if (r == DM_MAPIO_REMAPPED && pgpath->pg->ps.type->start_io) |
| 387 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, &pgpath->path, |
| 388 | nr_bytes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | |
| 390 | spin_unlock_irqrestore(&m->lock, flags); |
| 391 | |
| 392 | return r; |
| 393 | } |
| 394 | |
| 395 | /* |
| 396 | * If we run out of usable paths, should we queue I/O or error it? |
| 397 | */ |
Alasdair G Kergon | 485ef69 | 2005-09-27 21:45:45 -0700 | [diff] [blame] | 398 | static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, |
| 399 | unsigned save_old_value) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | { |
| 401 | unsigned long flags; |
| 402 | |
| 403 | spin_lock_irqsave(&m->lock, flags); |
| 404 | |
Alasdair G Kergon | 485ef69 | 2005-09-27 21:45:45 -0700 | [diff] [blame] | 405 | if (save_old_value) |
| 406 | m->saved_queue_if_no_path = m->queue_if_no_path; |
| 407 | else |
| 408 | m->saved_queue_if_no_path = queue_if_no_path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | m->queue_if_no_path = queue_if_no_path; |
Alasdair G Kergon | c3cd4f6 | 2005-07-12 15:53:04 -0700 | [diff] [blame] | 410 | if (!m->queue_if_no_path && m->queue_size) |
Alasdair G Kergon | c557308 | 2005-05-05 16:16:07 -0700 | [diff] [blame] | 411 | queue_work(kmultipathd, &m->process_queued_ios); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | |
| 413 | spin_unlock_irqrestore(&m->lock, flags); |
| 414 | |
| 415 | return 0; |
| 416 | } |
| 417 | |
| 418 | /*----------------------------------------------------------------- |
| 419 | * The multipath daemon is responsible for resubmitting queued ios. |
| 420 | *---------------------------------------------------------------*/ |
| 421 | |
| 422 | static void dispatch_queued_ios(struct multipath *m) |
| 423 | { |
| 424 | int r; |
| 425 | unsigned long flags; |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 426 | struct dm_mpath_io *mpio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | union map_info *info; |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 428 | struct request *clone, *n; |
| 429 | LIST_HEAD(cl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | |
| 431 | spin_lock_irqsave(&m->lock, flags); |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 432 | list_splice_init(&m->queued_ios, &cl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | spin_unlock_irqrestore(&m->lock, flags); |
| 434 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 435 | list_for_each_entry_safe(clone, n, &cl, queuelist) { |
| 436 | list_del_init(&clone->queuelist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 438 | info = dm_get_rq_mapinfo(clone); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | mpio = info->ptr; |
| 440 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 441 | r = map_io(m, clone, mpio, 1); |
| 442 | if (r < 0) { |
| 443 | mempool_free(mpio, m->mpio_pool); |
| 444 | dm_kill_unmapped_request(clone, r); |
| 445 | } else if (r == DM_MAPIO_REMAPPED) |
| 446 | dm_dispatch_request(clone); |
| 447 | else if (r == DM_MAPIO_REQUEUE) { |
| 448 | mempool_free(mpio, m->mpio_pool); |
| 449 | dm_requeue_unmapped_request(clone); |
| 450 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | } |
| 452 | } |
| 453 | |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 454 | static void process_queued_ios(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | { |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 456 | struct multipath *m = |
| 457 | container_of(work, struct multipath, process_queued_ios); |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 458 | struct pgpath *pgpath = NULL; |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 459 | unsigned must_queue = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | unsigned long flags; |
| 461 | |
| 462 | spin_lock_irqsave(&m->lock, flags); |
| 463 | |
Alasdair G Kergon | c3cd4f6 | 2005-07-12 15:53:04 -0700 | [diff] [blame] | 464 | if (!m->queue_size) |
| 465 | goto out; |
| 466 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | if (!m->current_pgpath) |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 468 | __choose_pgpath(m, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | |
| 470 | pgpath = m->current_pgpath; |
| 471 | |
Alasdair G Kergon | c3cd4f6 | 2005-07-12 15:53:04 -0700 | [diff] [blame] | 472 | if ((pgpath && !m->queue_io) || |
| 473 | (!pgpath && !m->queue_if_no_path)) |
| 474 | must_queue = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | |
Kiyoshi Ueda | fb61264 | 2010-03-06 02:32:18 +0000 | [diff] [blame] | 476 | if (m->pg_init_required && !m->pg_init_in_progress && pgpath) |
| 477 | __pg_init_all_paths(m); |
| 478 | |
Alasdair G Kergon | c3cd4f6 | 2005-07-12 15:53:04 -0700 | [diff] [blame] | 479 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | spin_unlock_irqrestore(&m->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | if (!must_queue) |
| 482 | dispatch_queued_ios(m); |
| 483 | } |
| 484 | |
| 485 | /* |
| 486 | * An event is triggered whenever a path is taken out of use. |
| 487 | * Includes path failure and PG bypass. |
| 488 | */ |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 489 | static void trigger_event(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | { |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 491 | struct multipath *m = |
| 492 | container_of(work, struct multipath, trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | |
| 494 | dm_table_event(m->ti->table); |
| 495 | } |
| 496 | |
| 497 | /*----------------------------------------------------------------- |
| 498 | * Constructor/argument parsing: |
| 499 | * <#multipath feature args> [<arg>]* |
| 500 | * <#hw_handler args> [hw_handler [<arg>]*] |
| 501 | * <#priority groups> |
| 502 | * <initial priority group> |
| 503 | * [<selector> <#selector args> [<arg>]* |
| 504 | * <#paths> <#per-path selector args> |
| 505 | * [<path> [<arg>]* ]+ ]+ |
| 506 | *---------------------------------------------------------------*/ |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 507 | 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] | 508 | struct dm_target *ti) |
| 509 | { |
| 510 | int r; |
| 511 | struct path_selector_type *pst; |
| 512 | unsigned ps_argc; |
| 513 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 514 | static struct dm_arg _args[] = { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 515 | {0, 1024, "invalid number of path selector args"}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | }; |
| 517 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 518 | pst = dm_get_path_selector(dm_shift_arg(as)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | if (!pst) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 520 | ti->error = "unknown path selector type"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | return -EINVAL; |
| 522 | } |
| 523 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 524 | r = dm_read_arg_group(_args, as, &ps_argc, &ti->error); |
Mikulas Patocka | 371b2e3 | 2008-07-21 12:00:24 +0100 | [diff] [blame] | 525 | if (r) { |
| 526 | dm_put_path_selector(pst); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | return -EINVAL; |
Mikulas Patocka | 371b2e3 | 2008-07-21 12:00:24 +0100 | [diff] [blame] | 528 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | |
| 530 | r = pst->create(&pg->ps, ps_argc, as->argv); |
| 531 | if (r) { |
| 532 | dm_put_path_selector(pst); |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 533 | ti->error = "path selector constructor failed"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | return r; |
| 535 | } |
| 536 | |
| 537 | pg->ps.type = pst; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 538 | dm_consume_args(as, ps_argc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | |
| 540 | return 0; |
| 541 | } |
| 542 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 543 | 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] | 544 | struct dm_target *ti) |
| 545 | { |
| 546 | int r; |
| 547 | struct pgpath *p; |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 548 | struct multipath *m = ti->private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | |
| 550 | /* we need at least a path arg */ |
| 551 | if (as->argc < 1) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 552 | ti->error = "no device given"; |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 553 | return ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | } |
| 555 | |
| 556 | p = alloc_pgpath(); |
| 557 | if (!p) |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 558 | return ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 560 | 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] | 561 | &p->path.dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | if (r) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 563 | ti->error = "error getting device"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | goto bad; |
| 565 | } |
| 566 | |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 567 | if (m->hw_handler_name) { |
Hannes Reinecke | a0cf7ea | 2009-06-22 10:12:11 +0100 | [diff] [blame] | 568 | struct request_queue *q = bdev_get_queue(p->path.dev->bdev); |
| 569 | |
| 570 | r = scsi_dh_attach(q, m->hw_handler_name); |
| 571 | if (r == -EBUSY) { |
| 572 | /* |
| 573 | * Already attached to different hw_handler, |
| 574 | * try to reattach with correct one. |
| 575 | */ |
| 576 | scsi_dh_detach(q); |
| 577 | r = scsi_dh_attach(q, m->hw_handler_name); |
| 578 | } |
| 579 | |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 580 | if (r < 0) { |
Hannes Reinecke | a0cf7ea | 2009-06-22 10:12:11 +0100 | [diff] [blame] | 581 | ti->error = "error attaching hardware handler"; |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 582 | dm_put_device(ti, p->path.dev); |
| 583 | goto bad; |
| 584 | } |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 585 | |
| 586 | if (m->hw_handler_params) { |
| 587 | r = scsi_dh_set_params(q, m->hw_handler_params); |
| 588 | if (r < 0) { |
| 589 | ti->error = "unable to set hardware " |
| 590 | "handler parameters"; |
| 591 | scsi_dh_detach(q); |
| 592 | dm_put_device(ti, p->path.dev); |
| 593 | goto bad; |
| 594 | } |
| 595 | } |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 596 | } |
| 597 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
| 599 | if (r) { |
| 600 | dm_put_device(ti, p->path.dev); |
| 601 | goto bad; |
| 602 | } |
| 603 | |
| 604 | return p; |
| 605 | |
| 606 | bad: |
| 607 | free_pgpath(p); |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 608 | return ERR_PTR(r); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | } |
| 610 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 611 | static struct priority_group *parse_priority_group(struct dm_arg_set *as, |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 612 | struct multipath *m) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | { |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 614 | static struct dm_arg _args[] = { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 615 | {1, 1024, "invalid number of paths"}, |
| 616 | {0, 1024, "invalid number of selector args"} |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | }; |
| 618 | |
| 619 | int r; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 620 | unsigned i, nr_selector_args, nr_args; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | struct priority_group *pg; |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 622 | struct dm_target *ti = m->ti; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | |
| 624 | if (as->argc < 2) { |
| 625 | as->argc = 0; |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 626 | ti->error = "not enough priority group arguments"; |
| 627 | return ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 628 | } |
| 629 | |
| 630 | pg = alloc_priority_group(); |
| 631 | if (!pg) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 632 | ti->error = "couldn't allocate priority group"; |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 633 | return ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | } |
| 635 | pg->m = m; |
| 636 | |
| 637 | r = parse_path_selector(as, pg, ti); |
| 638 | if (r) |
| 639 | goto bad; |
| 640 | |
| 641 | /* |
| 642 | * read the paths |
| 643 | */ |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 644 | r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | if (r) |
| 646 | goto bad; |
| 647 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 648 | r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 649 | if (r) |
| 650 | goto bad; |
| 651 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 652 | nr_args = 1 + nr_selector_args; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | for (i = 0; i < pg->nr_pgpaths; i++) { |
| 654 | struct pgpath *pgpath; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 655 | struct dm_arg_set path_args; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 657 | if (as->argc < nr_args) { |
Mikulas Patocka | 148acff | 2008-07-21 12:00:30 +0100 | [diff] [blame] | 658 | ti->error = "not enough path parameters"; |
Alasdair G Kergon | 6bbf79a | 2010-08-12 04:13:49 +0100 | [diff] [blame] | 659 | r = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | goto bad; |
Mikulas Patocka | 148acff | 2008-07-21 12:00:30 +0100 | [diff] [blame] | 661 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 663 | path_args.argc = nr_args; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | path_args.argv = as->argv; |
| 665 | |
| 666 | pgpath = parse_path(&path_args, &pg->ps, ti); |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 667 | if (IS_ERR(pgpath)) { |
| 668 | r = PTR_ERR(pgpath); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | goto bad; |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 670 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | |
| 672 | pgpath->pg = pg; |
| 673 | list_add_tail(&pgpath->list, &pg->pgpaths); |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 674 | dm_consume_args(as, nr_args); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | } |
| 676 | |
| 677 | return pg; |
| 678 | |
| 679 | bad: |
| 680 | free_priority_group(pg, ti); |
Benjamin Marzinski | 01460f3 | 2008-10-10 13:36:57 +0100 | [diff] [blame] | 681 | return ERR_PTR(r); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | } |
| 683 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 684 | 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] | 685 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 686 | unsigned hw_argc; |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 687 | int ret; |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 688 | struct dm_target *ti = m->ti; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 690 | static struct dm_arg _args[] = { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 691 | {0, 1024, "invalid number of hardware handler args"}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | }; |
| 693 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 694 | if (dm_read_arg_group(_args, as, &hw_argc, &ti->error)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | return -EINVAL; |
| 696 | |
| 697 | if (!hw_argc) |
| 698 | return 0; |
| 699 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 700 | m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL); |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 701 | request_module("scsi_dh_%s", m->hw_handler_name); |
| 702 | if (scsi_dh_handler_exist(m->hw_handler_name) == 0) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 703 | ti->error = "unknown hardware handler type"; |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 704 | ret = -EINVAL; |
| 705 | goto fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | } |
Chandra Seetharaman | 14e98c5 | 2008-11-13 23:39:06 +0000 | [diff] [blame] | 707 | |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 708 | if (hw_argc > 1) { |
| 709 | char *p; |
| 710 | int i, j, len = 4; |
| 711 | |
| 712 | for (i = 0; i <= hw_argc - 2; i++) |
| 713 | len += strlen(as->argv[i]) + 1; |
| 714 | p = m->hw_handler_params = kzalloc(len, GFP_KERNEL); |
| 715 | if (!p) { |
| 716 | ti->error = "memory allocation failed"; |
| 717 | ret = -ENOMEM; |
| 718 | goto fail; |
| 719 | } |
| 720 | j = sprintf(p, "%d", hw_argc - 1); |
| 721 | for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1) |
| 722 | j = sprintf(p, "%s", as->argv[i]); |
| 723 | } |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 724 | dm_consume_args(as, hw_argc - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | |
| 726 | return 0; |
Chandra Seetharaman | 2bfd2e1 | 2009-08-03 12:42:45 -0700 | [diff] [blame] | 727 | fail: |
| 728 | kfree(m->hw_handler_name); |
| 729 | m->hw_handler_name = NULL; |
| 730 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | } |
| 732 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 733 | static int parse_features(struct dm_arg_set *as, struct multipath *m) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | { |
| 735 | int r; |
| 736 | unsigned argc; |
Micha³ Miros³aw | 28f16c2 | 2006-10-03 01:15:33 -0700 | [diff] [blame] | 737 | struct dm_target *ti = m->ti; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 738 | const char *arg_name; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 740 | static struct dm_arg _args[] = { |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 741 | {0, 5, "invalid number of feature args"}, |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 742 | {1, 50, "pg_init_retries must be between 1 and 50"}, |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 743 | {0, 60000, "pg_init_delay_msecs must be between 0 and 60000"}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | }; |
| 745 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 746 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | if (r) |
| 748 | return -EINVAL; |
| 749 | |
| 750 | if (!argc) |
| 751 | return 0; |
| 752 | |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 753 | do { |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 754 | arg_name = dm_shift_arg(as); |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 755 | argc--; |
| 756 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 757 | if (!strcasecmp(arg_name, "queue_if_no_path")) { |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 758 | r = queue_if_no_path(m, 1, 0); |
| 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 | |
Mikulas Patocka | 8627921 | 2009-06-22 10:12:24 +0100 | [diff] [blame] | 854 | ti->num_flush_requests = 1; |
Mike Snitzer | 959eb4e | 2010-08-12 04:14:32 +0100 | [diff] [blame] | 855 | ti->num_discard_requests = 1; |
Mikulas Patocka | 8627921 | 2009-06-22 10:12:24 +0100 | [diff] [blame] | 856 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | return 0; |
| 858 | |
| 859 | bad: |
| 860 | free_multipath(m); |
| 861 | return r; |
| 862 | } |
| 863 | |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 864 | static void multipath_wait_for_pg_init_completion(struct multipath *m) |
| 865 | { |
| 866 | DECLARE_WAITQUEUE(wait, current); |
| 867 | unsigned long flags; |
| 868 | |
| 869 | add_wait_queue(&m->pg_init_wait, &wait); |
| 870 | |
| 871 | while (1) { |
| 872 | set_current_state(TASK_UNINTERRUPTIBLE); |
| 873 | |
| 874 | spin_lock_irqsave(&m->lock, flags); |
| 875 | if (!m->pg_init_in_progress) { |
| 876 | spin_unlock_irqrestore(&m->lock, flags); |
| 877 | break; |
| 878 | } |
| 879 | spin_unlock_irqrestore(&m->lock, flags); |
| 880 | |
| 881 | io_schedule(); |
| 882 | } |
| 883 | set_current_state(TASK_RUNNING); |
| 884 | |
| 885 | remove_wait_queue(&m->pg_init_wait, &wait); |
| 886 | } |
| 887 | |
| 888 | static void flush_multipath_work(struct multipath *m) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 889 | { |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 890 | flush_workqueue(kmpath_handlerd); |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 891 | multipath_wait_for_pg_init_completion(m); |
Alasdair G Kergon | a044d01 | 2005-07-12 15:53:02 -0700 | [diff] [blame] | 892 | flush_workqueue(kmultipathd); |
Tejun Heo | d5ffa38 | 2011-01-13 19:59:56 +0000 | [diff] [blame] | 893 | flush_work_sync(&m->trigger_event); |
Kiyoshi Ueda | 6df400a | 2009-12-10 23:52:19 +0000 | [diff] [blame] | 894 | } |
| 895 | |
| 896 | static void multipath_dtr(struct dm_target *ti) |
| 897 | { |
| 898 | struct multipath *m = ti->private; |
| 899 | |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 900 | flush_multipath_work(m); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | free_multipath(m); |
| 902 | } |
| 903 | |
| 904 | /* |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 905 | * Map cloned requests |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 906 | */ |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 907 | static int multipath_map(struct dm_target *ti, struct request *clone, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 908 | union map_info *map_context) |
| 909 | { |
| 910 | int r; |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 911 | struct dm_mpath_io *mpio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 912 | struct multipath *m = (struct multipath *) ti->private; |
| 913 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 914 | mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC); |
| 915 | if (!mpio) |
| 916 | /* ENOMEM, requeue */ |
| 917 | return DM_MAPIO_REQUEUE; |
| 918 | memset(mpio, 0, sizeof(*mpio)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 919 | |
| 920 | map_context->ptr = mpio; |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 921 | clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; |
| 922 | r = map_io(m, clone, mpio, 0); |
Kiyoshi Ueda | 45e1572 | 2006-12-08 02:41:10 -0800 | [diff] [blame] | 923 | if (r < 0 || r == DM_MAPIO_REQUEUE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | mempool_free(mpio, m->mpio_pool); |
| 925 | |
| 926 | return r; |
| 927 | } |
| 928 | |
| 929 | /* |
| 930 | * Take a path out of use. |
| 931 | */ |
| 932 | static int fail_path(struct pgpath *pgpath) |
| 933 | { |
| 934 | unsigned long flags; |
| 935 | struct multipath *m = pgpath->pg->m; |
| 936 | |
| 937 | spin_lock_irqsave(&m->lock, flags); |
| 938 | |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 939 | if (!pgpath->is_active) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 940 | goto out; |
| 941 | |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 942 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 943 | |
| 944 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 945 | pgpath->is_active = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | pgpath->fail_count++; |
| 947 | |
| 948 | m->nr_valid_paths--; |
| 949 | |
| 950 | if (pgpath == m->current_pgpath) |
| 951 | m->current_pgpath = NULL; |
| 952 | |
Mike Anderson | b15546f | 2007-10-19 22:48:02 +0100 | [diff] [blame] | 953 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
| 954 | pgpath->path.dev->name, m->nr_valid_paths); |
| 955 | |
Alasdair G Kergon | fe9cf30 | 2009-01-06 03:05:13 +0000 | [diff] [blame] | 956 | schedule_work(&m->trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | |
| 958 | out: |
| 959 | spin_unlock_irqrestore(&m->lock, flags); |
| 960 | |
| 961 | return 0; |
| 962 | } |
| 963 | |
| 964 | /* |
| 965 | * Reinstate a previously-failed path |
| 966 | */ |
| 967 | static int reinstate_path(struct pgpath *pgpath) |
| 968 | { |
| 969 | int r = 0; |
| 970 | unsigned long flags; |
| 971 | struct multipath *m = pgpath->pg->m; |
| 972 | |
| 973 | spin_lock_irqsave(&m->lock, flags); |
| 974 | |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 975 | if (pgpath->is_active) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | goto out; |
| 977 | |
Alasdair G Kergon | def052d | 2008-07-21 12:00:31 +0100 | [diff] [blame] | 978 | if (!pgpath->pg->ps.type->reinstate_path) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | DMWARN("Reinstate path not supported by path selector %s", |
| 980 | pgpath->pg->ps.type->name); |
| 981 | r = -EINVAL; |
| 982 | goto out; |
| 983 | } |
| 984 | |
| 985 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); |
| 986 | if (r) |
| 987 | goto out; |
| 988 | |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 989 | pgpath->is_active = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 990 | |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 991 | if (!m->nr_valid_paths++ && m->queue_size) { |
| 992 | m->current_pgpath = NULL; |
Alasdair G Kergon | c557308 | 2005-05-05 16:16:07 -0700 | [diff] [blame] | 993 | queue_work(kmultipathd, &m->process_queued_ios); |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 994 | } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 995 | if (queue_work(kmpath_handlerd, &pgpath->activate_path.work)) |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 996 | m->pg_init_in_progress++; |
| 997 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 998 | |
Mike Anderson | b15546f | 2007-10-19 22:48:02 +0100 | [diff] [blame] | 999 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
| 1000 | pgpath->path.dev->name, m->nr_valid_paths); |
| 1001 | |
Alasdair G Kergon | fe9cf30 | 2009-01-06 03:05:13 +0000 | [diff] [blame] | 1002 | schedule_work(&m->trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | |
| 1004 | out: |
| 1005 | spin_unlock_irqrestore(&m->lock, flags); |
| 1006 | |
| 1007 | return r; |
| 1008 | } |
| 1009 | |
| 1010 | /* |
| 1011 | * Fail or reinstate all paths that match the provided struct dm_dev. |
| 1012 | */ |
| 1013 | static int action_dev(struct multipath *m, struct dm_dev *dev, |
| 1014 | action_fn action) |
| 1015 | { |
Mike Snitzer | 19040c0 | 2011-03-24 13:54:31 +0000 | [diff] [blame] | 1016 | int r = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1017 | struct pgpath *pgpath; |
| 1018 | struct priority_group *pg; |
| 1019 | |
| 1020 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1021 | list_for_each_entry(pgpath, &pg->pgpaths, list) { |
| 1022 | if (pgpath->path.dev == dev) |
| 1023 | r = action(pgpath); |
| 1024 | } |
| 1025 | } |
| 1026 | |
| 1027 | return r; |
| 1028 | } |
| 1029 | |
| 1030 | /* |
| 1031 | * Temporarily try to avoid having to use the specified PG |
| 1032 | */ |
| 1033 | static void bypass_pg(struct multipath *m, struct priority_group *pg, |
| 1034 | int bypassed) |
| 1035 | { |
| 1036 | unsigned long flags; |
| 1037 | |
| 1038 | spin_lock_irqsave(&m->lock, flags); |
| 1039 | |
| 1040 | pg->bypassed = bypassed; |
| 1041 | m->current_pgpath = NULL; |
| 1042 | m->current_pg = NULL; |
| 1043 | |
| 1044 | spin_unlock_irqrestore(&m->lock, flags); |
| 1045 | |
Alasdair G Kergon | fe9cf30 | 2009-01-06 03:05:13 +0000 | [diff] [blame] | 1046 | schedule_work(&m->trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1047 | } |
| 1048 | |
| 1049 | /* |
| 1050 | * Switch to using the specified PG from the next I/O that gets mapped |
| 1051 | */ |
| 1052 | static int switch_pg_num(struct multipath *m, const char *pgstr) |
| 1053 | { |
| 1054 | struct priority_group *pg; |
| 1055 | unsigned pgnum; |
| 1056 | unsigned long flags; |
| 1057 | |
| 1058 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || |
| 1059 | (pgnum > m->nr_priority_groups)) { |
| 1060 | DMWARN("invalid PG number supplied to switch_pg_num"); |
| 1061 | return -EINVAL; |
| 1062 | } |
| 1063 | |
| 1064 | spin_lock_irqsave(&m->lock, flags); |
| 1065 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1066 | pg->bypassed = 0; |
| 1067 | if (--pgnum) |
| 1068 | continue; |
| 1069 | |
| 1070 | m->current_pgpath = NULL; |
| 1071 | m->current_pg = NULL; |
| 1072 | m->next_pg = pg; |
| 1073 | } |
| 1074 | spin_unlock_irqrestore(&m->lock, flags); |
| 1075 | |
Alasdair G Kergon | fe9cf30 | 2009-01-06 03:05:13 +0000 | [diff] [blame] | 1076 | schedule_work(&m->trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | return 0; |
| 1078 | } |
| 1079 | |
| 1080 | /* |
| 1081 | * Set/clear bypassed status of a PG. |
| 1082 | * PGs are numbered upwards from 1 in the order they were declared. |
| 1083 | */ |
| 1084 | static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) |
| 1085 | { |
| 1086 | struct priority_group *pg; |
| 1087 | unsigned pgnum; |
| 1088 | |
| 1089 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || |
| 1090 | (pgnum > m->nr_priority_groups)) { |
| 1091 | DMWARN("invalid PG number supplied to bypass_pg"); |
| 1092 | return -EINVAL; |
| 1093 | } |
| 1094 | |
| 1095 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1096 | if (!--pgnum) |
| 1097 | break; |
| 1098 | } |
| 1099 | |
| 1100 | bypass_pg(m, pg, bypassed); |
| 1101 | return 0; |
| 1102 | } |
| 1103 | |
| 1104 | /* |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 1105 | * Should we retry pg_init immediately? |
| 1106 | */ |
| 1107 | static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) |
| 1108 | { |
| 1109 | unsigned long flags; |
| 1110 | int limit_reached = 0; |
| 1111 | |
| 1112 | spin_lock_irqsave(&m->lock, flags); |
| 1113 | |
| 1114 | if (m->pg_init_count <= m->pg_init_retries) |
| 1115 | m->pg_init_required = 1; |
| 1116 | else |
| 1117 | limit_reached = 1; |
| 1118 | |
| 1119 | spin_unlock_irqrestore(&m->lock, flags); |
| 1120 | |
| 1121 | return limit_reached; |
| 1122 | } |
| 1123 | |
Chandra Seetharaman | 3ae31f6 | 2009-10-21 09:22:46 -0700 | [diff] [blame] | 1124 | static void pg_init_done(void *data, int errors) |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1125 | { |
Moger, Babu | 83c0d5d | 2010-03-06 02:29:45 +0000 | [diff] [blame] | 1126 | struct pgpath *pgpath = data; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1127 | struct priority_group *pg = pgpath->pg; |
| 1128 | struct multipath *m = pg->m; |
| 1129 | unsigned long flags; |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1130 | unsigned delay_retry = 0; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1131 | |
| 1132 | /* device or driver problems */ |
| 1133 | switch (errors) { |
| 1134 | case SCSI_DH_OK: |
| 1135 | break; |
| 1136 | case SCSI_DH_NOSYS: |
| 1137 | if (!m->hw_handler_name) { |
| 1138 | errors = 0; |
| 1139 | break; |
| 1140 | } |
Moger, Babu | f7b934c | 2010-03-06 02:29:49 +0000 | [diff] [blame] | 1141 | DMERR("Could not failover the device: Handler scsi_dh_%s " |
| 1142 | "Error %d.", m->hw_handler_name, errors); |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1143 | /* |
| 1144 | * Fail path for now, so we do not ping pong |
| 1145 | */ |
| 1146 | fail_path(pgpath); |
| 1147 | break; |
| 1148 | case SCSI_DH_DEV_TEMP_BUSY: |
| 1149 | /* |
| 1150 | * Probably doing something like FW upgrade on the |
| 1151 | * controller so try the other pg. |
| 1152 | */ |
| 1153 | bypass_pg(m, pg, 1); |
| 1154 | break; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1155 | case SCSI_DH_RETRY: |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1156 | /* Wait before retrying. */ |
| 1157 | delay_retry = 1; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1158 | case SCSI_DH_IMM_RETRY: |
| 1159 | case SCSI_DH_RES_TEMP_UNAVAIL: |
| 1160 | if (pg_init_limit_reached(m, pgpath)) |
| 1161 | fail_path(pgpath); |
| 1162 | errors = 0; |
| 1163 | break; |
| 1164 | default: |
| 1165 | /* |
| 1166 | * We probably do not want to fail the path for a device |
| 1167 | * error, but this is what the old dm did. In future |
| 1168 | * patches we can do more advanced handling. |
| 1169 | */ |
| 1170 | fail_path(pgpath); |
| 1171 | } |
| 1172 | |
| 1173 | spin_lock_irqsave(&m->lock, flags); |
| 1174 | if (errors) { |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 1175 | if (pgpath == m->current_pgpath) { |
| 1176 | DMERR("Could not failover device. Error %d.", errors); |
| 1177 | m->current_pgpath = NULL; |
| 1178 | m->current_pg = NULL; |
| 1179 | } |
Kiyoshi Ueda | d0259bf | 2010-03-06 02:30:02 +0000 | [diff] [blame] | 1180 | } else if (!m->pg_init_required) |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1181 | pg->bypassed = 0; |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1182 | |
Kiyoshi Ueda | d0259bf | 2010-03-06 02:30:02 +0000 | [diff] [blame] | 1183 | if (--m->pg_init_in_progress) |
| 1184 | /* Activations of other paths are still on going */ |
| 1185 | goto out; |
| 1186 | |
| 1187 | if (!m->pg_init_required) |
| 1188 | m->queue_io = 0; |
| 1189 | |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1190 | m->pg_init_delay_retry = delay_retry; |
Kiyoshi Ueda | d0259bf | 2010-03-06 02:30:02 +0000 | [diff] [blame] | 1191 | queue_work(kmultipathd, &m->process_queued_ios); |
| 1192 | |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 1193 | /* |
| 1194 | * Wake up any thread waiting to suspend. |
| 1195 | */ |
| 1196 | wake_up(&m->pg_init_wait); |
| 1197 | |
Kiyoshi Ueda | d0259bf | 2010-03-06 02:30:02 +0000 | [diff] [blame] | 1198 | out: |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1199 | spin_unlock_irqrestore(&m->lock, flags); |
| 1200 | } |
| 1201 | |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1202 | static void activate_path(struct work_struct *work) |
| 1203 | { |
Chandra Seetharaman | e54f77d | 2009-06-22 10:12:12 +0100 | [diff] [blame] | 1204 | struct pgpath *pgpath = |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1205 | container_of(work, struct pgpath, activate_path.work); |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1206 | |
Chandra Seetharaman | 3ae31f6 | 2009-10-21 09:22:46 -0700 | [diff] [blame] | 1207 | scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), |
Moger, Babu | 83c0d5d | 2010-03-06 02:29:45 +0000 | [diff] [blame] | 1208 | pg_init_done, pgpath); |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1209 | } |
| 1210 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1211 | /* |
| 1212 | * end_io handling |
| 1213 | */ |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1214 | static int do_end_io(struct multipath *m, struct request *clone, |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 1215 | int error, struct dm_mpath_io *mpio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1216 | { |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1217 | /* |
| 1218 | * We don't queue any clone request inside the multipath target |
| 1219 | * during end I/O handling, since those clone requests don't have |
| 1220 | * bio clones. If we queue them inside the multipath target, |
| 1221 | * we need to make bio clones, that requires memory allocation. |
| 1222 | * (See drivers/md/dm.c:end_clone_bio() about why the clone requests |
| 1223 | * don't have bio clones.) |
| 1224 | * Instead of queueing the clone request here, we queue the original |
| 1225 | * request into dm core, which will remake a clone request and |
| 1226 | * clone bios for it and resubmit it later. |
| 1227 | */ |
| 1228 | int r = DM_ENDIO_REQUEUE; |
Stefan Bader | 640eb3b | 2005-11-21 21:32:35 -0800 | [diff] [blame] | 1229 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1230 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1231 | if (!error && !clone->errors) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | return 0; /* I/O complete */ |
| 1233 | |
Martin K. Petersen | 6f13f6f | 2011-05-29 13:02:55 +0100 | [diff] [blame] | 1234 | if (error == -EOPNOTSUPP || error == -EREMOTEIO || error == -EILSEQ) |
Mike Snitzer | 959eb4e | 2010-08-12 04:14:32 +0100 | [diff] [blame] | 1235 | return error; |
| 1236 | |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1237 | if (mpio->pgpath) |
| 1238 | fail_path(mpio->pgpath); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1239 | |
Stefan Bader | 640eb3b | 2005-11-21 21:32:35 -0800 | [diff] [blame] | 1240 | spin_lock_irqsave(&m->lock, flags); |
Hannes Reinecke | 751b2a7 | 2011-01-18 10:13:12 +0100 | [diff] [blame] | 1241 | if (!m->nr_valid_paths) { |
| 1242 | if (!m->queue_if_no_path) { |
| 1243 | if (!__must_push_back(m)) |
| 1244 | r = -EIO; |
| 1245 | } else { |
| 1246 | if (error == -EBADE) |
| 1247 | r = error; |
| 1248 | } |
| 1249 | } |
Stefan Bader | 640eb3b | 2005-11-21 21:32:35 -0800 | [diff] [blame] | 1250 | spin_unlock_irqrestore(&m->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1251 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1252 | return r; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1253 | } |
| 1254 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1255 | static int multipath_end_io(struct dm_target *ti, struct request *clone, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1256 | int error, union map_info *map_context) |
| 1257 | { |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 1258 | struct multipath *m = ti->private; |
| 1259 | struct dm_mpath_io *mpio = map_context->ptr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1260 | struct pgpath *pgpath = mpio->pgpath; |
| 1261 | struct path_selector *ps; |
| 1262 | int r; |
| 1263 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1264 | r = do_end_io(m, clone, error, mpio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1265 | if (pgpath) { |
| 1266 | ps = &pgpath->pg->ps; |
| 1267 | if (ps->type->end_io) |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 1268 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1269 | } |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1270 | mempool_free(mpio, m->mpio_pool); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1271 | |
| 1272 | return r; |
| 1273 | } |
| 1274 | |
| 1275 | /* |
| 1276 | * 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] | 1277 | * the last path fails we must error any remaining I/O. |
| 1278 | * Note that if the freeze_bdev fails while suspending, the |
| 1279 | * queue_if_no_path state is lost - userspace should reset it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1280 | */ |
| 1281 | static void multipath_presuspend(struct dm_target *ti) |
| 1282 | { |
| 1283 | struct multipath *m = (struct multipath *) ti->private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1284 | |
Alasdair G Kergon | 485ef69 | 2005-09-27 21:45:45 -0700 | [diff] [blame] | 1285 | queue_if_no_path(m, 0, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1286 | } |
| 1287 | |
Kiyoshi Ueda | 6df400a | 2009-12-10 23:52:19 +0000 | [diff] [blame] | 1288 | static void multipath_postsuspend(struct dm_target *ti) |
| 1289 | { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1290 | struct multipath *m = ti->private; |
| 1291 | |
| 1292 | mutex_lock(&m->work_mutex); |
Kiyoshi Ueda | 2bded7b | 2010-03-06 02:32:13 +0000 | [diff] [blame] | 1293 | flush_multipath_work(m); |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1294 | mutex_unlock(&m->work_mutex); |
Kiyoshi Ueda | 6df400a | 2009-12-10 23:52:19 +0000 | [diff] [blame] | 1295 | } |
| 1296 | |
Alasdair G Kergon | 436d410 | 2005-07-12 15:53:03 -0700 | [diff] [blame] | 1297 | /* |
| 1298 | * Restore the queue_if_no_path setting. |
| 1299 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1300 | static void multipath_resume(struct dm_target *ti) |
| 1301 | { |
| 1302 | struct multipath *m = (struct multipath *) ti->private; |
| 1303 | unsigned long flags; |
| 1304 | |
| 1305 | spin_lock_irqsave(&m->lock, flags); |
Alasdair G Kergon | 436d410 | 2005-07-12 15:53:03 -0700 | [diff] [blame] | 1306 | m->queue_if_no_path = m->saved_queue_if_no_path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1307 | spin_unlock_irqrestore(&m->lock, flags); |
| 1308 | } |
| 1309 | |
| 1310 | /* |
| 1311 | * Info output has the following format: |
| 1312 | * num_multipath_feature_args [multipath_feature_args]* |
| 1313 | * num_handler_status_args [handler_status_args]* |
| 1314 | * num_groups init_group_number |
| 1315 | * [A|D|E num_ps_status_args [ps_status_args]* |
| 1316 | * num_paths num_selector_args |
| 1317 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ |
| 1318 | * |
| 1319 | * Table output has the following format (identical to the constructor string): |
| 1320 | * num_feature_args [features_args]* |
| 1321 | * num_handler_args hw_handler [hw_handler_args]* |
| 1322 | * num_groups init_group_number |
| 1323 | * [priority selector-name num_ps_args [ps_args]* |
| 1324 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ |
| 1325 | */ |
| 1326 | static int multipath_status(struct dm_target *ti, status_type_t type, |
| 1327 | char *result, unsigned int maxlen) |
| 1328 | { |
| 1329 | int sz = 0; |
| 1330 | unsigned long flags; |
| 1331 | struct multipath *m = (struct multipath *) ti->private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1332 | struct priority_group *pg; |
| 1333 | struct pgpath *p; |
| 1334 | unsigned pg_num; |
| 1335 | char state; |
| 1336 | |
| 1337 | spin_lock_irqsave(&m->lock, flags); |
| 1338 | |
| 1339 | /* Features */ |
| 1340 | if (type == STATUSTYPE_INFO) |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 1341 | DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count); |
| 1342 | else { |
| 1343 | DMEMIT("%u ", m->queue_if_no_path + |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1344 | (m->pg_init_retries > 0) * 2 + |
| 1345 | (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2); |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 1346 | if (m->queue_if_no_path) |
| 1347 | DMEMIT("queue_if_no_path "); |
| 1348 | if (m->pg_init_retries) |
| 1349 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); |
Chandra Seetharaman | 4e2d19e | 2011-01-13 20:00:01 +0000 | [diff] [blame] | 1350 | if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) |
| 1351 | DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs); |
Dave Wysochanski | c9e4558 | 2007-10-19 22:47:53 +0100 | [diff] [blame] | 1352 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1353 | |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1354 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1355 | DMEMIT("0 "); |
| 1356 | else |
Chandra Seetharaman | cfae5c9 | 2008-05-01 14:50:11 -0700 | [diff] [blame] | 1357 | DMEMIT("1 %s ", m->hw_handler_name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1358 | |
| 1359 | DMEMIT("%u ", m->nr_priority_groups); |
| 1360 | |
| 1361 | if (m->next_pg) |
| 1362 | pg_num = m->next_pg->pg_num; |
| 1363 | else if (m->current_pg) |
| 1364 | pg_num = m->current_pg->pg_num; |
| 1365 | else |
Mike Snitzer | a490a07 | 2011-03-24 13:54:33 +0000 | [diff] [blame] | 1366 | pg_num = (m->nr_priority_groups ? 1 : 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1367 | |
| 1368 | DMEMIT("%u ", pg_num); |
| 1369 | |
| 1370 | switch (type) { |
| 1371 | case STATUSTYPE_INFO: |
| 1372 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1373 | if (pg->bypassed) |
| 1374 | state = 'D'; /* Disabled */ |
| 1375 | else if (pg == m->current_pg) |
| 1376 | state = 'A'; /* Currently Active */ |
| 1377 | else |
| 1378 | state = 'E'; /* Enabled */ |
| 1379 | |
| 1380 | DMEMIT("%c ", state); |
| 1381 | |
| 1382 | if (pg->ps.type->status) |
| 1383 | sz += pg->ps.type->status(&pg->ps, NULL, type, |
| 1384 | result + sz, |
| 1385 | maxlen - sz); |
| 1386 | else |
| 1387 | DMEMIT("0 "); |
| 1388 | |
| 1389 | DMEMIT("%u %u ", pg->nr_pgpaths, |
| 1390 | pg->ps.type->info_args); |
| 1391 | |
| 1392 | list_for_each_entry(p, &pg->pgpaths, list) { |
| 1393 | DMEMIT("%s %s %u ", p->path.dev->name, |
Kiyoshi Ueda | 6680073 | 2008-10-10 13:36:58 +0100 | [diff] [blame] | 1394 | p->is_active ? "A" : "F", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1395 | p->fail_count); |
| 1396 | if (pg->ps.type->status) |
| 1397 | sz += pg->ps.type->status(&pg->ps, |
| 1398 | &p->path, type, result + sz, |
| 1399 | maxlen - sz); |
| 1400 | } |
| 1401 | } |
| 1402 | break; |
| 1403 | |
| 1404 | case STATUSTYPE_TABLE: |
| 1405 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1406 | DMEMIT("%s ", pg->ps.type->name); |
| 1407 | |
| 1408 | if (pg->ps.type->status) |
| 1409 | sz += pg->ps.type->status(&pg->ps, NULL, type, |
| 1410 | result + sz, |
| 1411 | maxlen - sz); |
| 1412 | else |
| 1413 | DMEMIT("0 "); |
| 1414 | |
| 1415 | DMEMIT("%u %u ", pg->nr_pgpaths, |
| 1416 | pg->ps.type->table_args); |
| 1417 | |
| 1418 | list_for_each_entry(p, &pg->pgpaths, list) { |
| 1419 | DMEMIT("%s ", p->path.dev->name); |
| 1420 | if (pg->ps.type->status) |
| 1421 | sz += pg->ps.type->status(&pg->ps, |
| 1422 | &p->path, type, result + sz, |
| 1423 | maxlen - sz); |
| 1424 | } |
| 1425 | } |
| 1426 | break; |
| 1427 | } |
| 1428 | |
| 1429 | spin_unlock_irqrestore(&m->lock, flags); |
| 1430 | |
| 1431 | return 0; |
| 1432 | } |
| 1433 | |
| 1434 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) |
| 1435 | { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1436 | int r = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1437 | struct dm_dev *dev; |
| 1438 | struct multipath *m = (struct multipath *) ti->private; |
| 1439 | action_fn action; |
| 1440 | |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1441 | mutex_lock(&m->work_mutex); |
| 1442 | |
Kiyoshi Ueda | c2f3d24 | 2009-12-10 23:52:27 +0000 | [diff] [blame] | 1443 | if (dm_suspended(ti)) { |
| 1444 | r = -EBUSY; |
| 1445 | goto out; |
| 1446 | } |
| 1447 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1448 | if (argc == 1) { |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1449 | if (!strcasecmp(argv[0], "queue_if_no_path")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1450 | r = queue_if_no_path(m, 1, 0); |
| 1451 | goto out; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1452 | } else if (!strcasecmp(argv[0], "fail_if_no_path")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1453 | r = queue_if_no_path(m, 0, 0); |
| 1454 | goto out; |
| 1455 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1456 | } |
| 1457 | |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1458 | if (argc != 2) { |
| 1459 | DMWARN("Unrecognised multipath message received."); |
| 1460 | goto out; |
| 1461 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1462 | |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1463 | if (!strcasecmp(argv[0], "disable_group")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1464 | r = bypass_pg_num(m, argv[1], 1); |
| 1465 | goto out; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1466 | } else if (!strcasecmp(argv[0], "enable_group")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1467 | r = bypass_pg_num(m, argv[1], 0); |
| 1468 | goto out; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1469 | } else if (!strcasecmp(argv[0], "switch_group")) { |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1470 | r = switch_pg_num(m, argv[1]); |
| 1471 | goto out; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1472 | } else if (!strcasecmp(argv[0], "reinstate_path")) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1473 | action = reinstate_path; |
Mike Snitzer | 498f010 | 2011-08-02 12:32:04 +0100 | [diff] [blame] | 1474 | else if (!strcasecmp(argv[0], "fail_path")) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1475 | action = fail_path; |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1476 | else { |
| 1477 | DMWARN("Unrecognised multipath message received."); |
| 1478 | goto out; |
| 1479 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1480 | |
Nikanth Karthikesan | 8215d6e | 2010-03-06 02:32:27 +0000 | [diff] [blame] | 1481 | 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] | 1482 | if (r) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 1483 | DMWARN("message: error getting device %s", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1484 | argv[1]); |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1485 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1486 | } |
| 1487 | |
| 1488 | r = action_dev(m, dev, action); |
| 1489 | |
| 1490 | dm_put_device(ti, dev); |
| 1491 | |
Mike Anderson | 6380f26 | 2009-12-10 23:52:21 +0000 | [diff] [blame] | 1492 | out: |
| 1493 | mutex_unlock(&m->work_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | return r; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1495 | } |
| 1496 | |
Al Viro | 647b3d0 | 2007-08-28 22:15:59 -0400 | [diff] [blame] | 1497 | static int multipath_ioctl(struct dm_target *ti, unsigned int cmd, |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1498 | unsigned long arg) |
| 1499 | { |
| 1500 | struct multipath *m = (struct multipath *) ti->private; |
| 1501 | struct block_device *bdev = NULL; |
Al Viro | 633a08b | 2007-08-29 20:34:12 -0400 | [diff] [blame] | 1502 | fmode_t mode = 0; |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1503 | unsigned long flags; |
| 1504 | int r = 0; |
| 1505 | |
| 1506 | spin_lock_irqsave(&m->lock, flags); |
| 1507 | |
| 1508 | if (!m->current_pgpath) |
Kiyoshi Ueda | 02ab823 | 2009-06-22 10:12:27 +0100 | [diff] [blame] | 1509 | __choose_pgpath(m, 0); |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1510 | |
Milan Broz | e90dae1 | 2006-10-03 01:15:22 -0700 | [diff] [blame] | 1511 | if (m->current_pgpath) { |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1512 | bdev = m->current_pgpath->path.dev->bdev; |
Al Viro | 633a08b | 2007-08-29 20:34:12 -0400 | [diff] [blame] | 1513 | mode = m->current_pgpath->path.dev->mode; |
Milan Broz | e90dae1 | 2006-10-03 01:15:22 -0700 | [diff] [blame] | 1514 | } |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1515 | |
| 1516 | if (m->queue_io) |
| 1517 | r = -EAGAIN; |
| 1518 | else if (!bdev) |
| 1519 | r = -EIO; |
| 1520 | |
| 1521 | spin_unlock_irqrestore(&m->lock, flags); |
| 1522 | |
Al Viro | 633a08b | 2007-08-29 20:34:12 -0400 | [diff] [blame] | 1523 | return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg); |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1524 | } |
| 1525 | |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 1526 | static int multipath_iterate_devices(struct dm_target *ti, |
| 1527 | iterate_devices_callout_fn fn, void *data) |
| 1528 | { |
| 1529 | struct multipath *m = ti->private; |
| 1530 | struct priority_group *pg; |
| 1531 | struct pgpath *p; |
| 1532 | int ret = 0; |
| 1533 | |
| 1534 | list_for_each_entry(pg, &m->priority_groups, list) { |
| 1535 | list_for_each_entry(p, &pg->pgpaths, list) { |
Mike Snitzer | 5dea271 | 2009-07-23 20:30:42 +0100 | [diff] [blame] | 1536 | ret = fn(ti, p->path.dev, ti->begin, ti->len, data); |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 1537 | if (ret) |
| 1538 | goto out; |
| 1539 | } |
| 1540 | } |
| 1541 | |
| 1542 | out: |
| 1543 | return ret; |
| 1544 | } |
| 1545 | |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1546 | static int __pgpath_busy(struct pgpath *pgpath) |
| 1547 | { |
| 1548 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); |
| 1549 | |
| 1550 | return dm_underlying_device_busy(q); |
| 1551 | } |
| 1552 | |
| 1553 | /* |
| 1554 | * We return "busy", only when we can map I/Os but underlying devices |
| 1555 | * are busy (so even if we map I/Os now, the I/Os will wait on |
| 1556 | * the underlying queue). |
| 1557 | * In other words, if we want to kill I/Os or queue them inside us |
| 1558 | * due to map unavailability, we don't return "busy". Otherwise, |
| 1559 | * dm core won't give us the I/Os and we can't do what we want. |
| 1560 | */ |
| 1561 | static int multipath_busy(struct dm_target *ti) |
| 1562 | { |
| 1563 | int busy = 0, has_active = 0; |
| 1564 | struct multipath *m = ti->private; |
| 1565 | struct priority_group *pg; |
| 1566 | struct pgpath *pgpath; |
| 1567 | unsigned long flags; |
| 1568 | |
| 1569 | spin_lock_irqsave(&m->lock, flags); |
| 1570 | |
| 1571 | /* Guess which priority_group will be used at next mapping time */ |
| 1572 | if (unlikely(!m->current_pgpath && m->next_pg)) |
| 1573 | pg = m->next_pg; |
| 1574 | else if (likely(m->current_pg)) |
| 1575 | pg = m->current_pg; |
| 1576 | else |
| 1577 | /* |
| 1578 | * We don't know which pg will be used at next mapping time. |
| 1579 | * We don't call __choose_pgpath() here to avoid to trigger |
| 1580 | * pg_init just by busy checking. |
| 1581 | * So we don't know whether underlying devices we will be using |
| 1582 | * at next mapping time are busy or not. Just try mapping. |
| 1583 | */ |
| 1584 | goto out; |
| 1585 | |
| 1586 | /* |
| 1587 | * If there is one non-busy active path at least, the path selector |
| 1588 | * will be able to select it. So we consider such a pg as not busy. |
| 1589 | */ |
| 1590 | busy = 1; |
| 1591 | list_for_each_entry(pgpath, &pg->pgpaths, list) |
| 1592 | if (pgpath->is_active) { |
| 1593 | has_active = 1; |
| 1594 | |
| 1595 | if (!__pgpath_busy(pgpath)) { |
| 1596 | busy = 0; |
| 1597 | break; |
| 1598 | } |
| 1599 | } |
| 1600 | |
| 1601 | if (!has_active) |
| 1602 | /* |
| 1603 | * No active path in this pg, so this pg won't be used and |
| 1604 | * the current_pg will be changed at next mapping time. |
| 1605 | * We need to try mapping to determine it. |
| 1606 | */ |
| 1607 | busy = 0; |
| 1608 | |
| 1609 | out: |
| 1610 | spin_unlock_irqrestore(&m->lock, flags); |
| 1611 | |
| 1612 | return busy; |
| 1613 | } |
| 1614 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1615 | /*----------------------------------------------------------------- |
| 1616 | * Module setup |
| 1617 | *---------------------------------------------------------------*/ |
| 1618 | static struct target_type multipath_target = { |
| 1619 | .name = "multipath", |
Mike Snitzer | 19040c0 | 2011-03-24 13:54:31 +0000 | [diff] [blame] | 1620 | .version = {1, 3, 0}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | .module = THIS_MODULE, |
| 1622 | .ctr = multipath_ctr, |
| 1623 | .dtr = multipath_dtr, |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1624 | .map_rq = multipath_map, |
| 1625 | .rq_end_io = multipath_end_io, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1626 | .presuspend = multipath_presuspend, |
Kiyoshi Ueda | 6df400a | 2009-12-10 23:52:19 +0000 | [diff] [blame] | 1627 | .postsuspend = multipath_postsuspend, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1628 | .resume = multipath_resume, |
| 1629 | .status = multipath_status, |
| 1630 | .message = multipath_message, |
Milan Broz | 9af4aa3 | 2006-10-03 01:15:20 -0700 | [diff] [blame] | 1631 | .ioctl = multipath_ioctl, |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 1632 | .iterate_devices = multipath_iterate_devices, |
Kiyoshi Ueda | f40c67f | 2009-06-22 10:12:37 +0100 | [diff] [blame] | 1633 | .busy = multipath_busy, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1634 | }; |
| 1635 | |
| 1636 | static int __init dm_multipath_init(void) |
| 1637 | { |
| 1638 | int r; |
| 1639 | |
| 1640 | /* allocate a slab for the dm_ios */ |
Alasdair G Kergon | 028867a | 2007-07-12 17:26:32 +0100 | [diff] [blame] | 1641 | _mpio_cache = KMEM_CACHE(dm_mpath_io, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1642 | if (!_mpio_cache) |
| 1643 | return -ENOMEM; |
| 1644 | |
| 1645 | r = dm_register_target(&multipath_target); |
| 1646 | if (r < 0) { |
Alasdair G Kergon | 0cd3312 | 2007-07-12 17:27:01 +0100 | [diff] [blame] | 1647 | DMERR("register failed %d", r); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1648 | kmem_cache_destroy(_mpio_cache); |
| 1649 | return -EINVAL; |
| 1650 | } |
| 1651 | |
Tejun Heo | 4d4d66a | 2011-01-13 19:59:57 +0000 | [diff] [blame] | 1652 | kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0); |
Alasdair G Kergon | c557308 | 2005-05-05 16:16:07 -0700 | [diff] [blame] | 1653 | if (!kmultipathd) { |
Alasdair G Kergon | 0cd3312 | 2007-07-12 17:27:01 +0100 | [diff] [blame] | 1654 | DMERR("failed to create workqueue kmpathd"); |
Alasdair G Kergon | c557308 | 2005-05-05 16:16:07 -0700 | [diff] [blame] | 1655 | dm_unregister_target(&multipath_target); |
| 1656 | kmem_cache_destroy(_mpio_cache); |
| 1657 | return -ENOMEM; |
| 1658 | } |
| 1659 | |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1660 | /* |
| 1661 | * A separate workqueue is used to handle the device handlers |
| 1662 | * to avoid overloading existing workqueue. Overloading the |
| 1663 | * old workqueue would also create a bottleneck in the |
| 1664 | * path of the storage hardware device activation. |
| 1665 | */ |
Tejun Heo | 4d4d66a | 2011-01-13 19:59:57 +0000 | [diff] [blame] | 1666 | kmpath_handlerd = alloc_ordered_workqueue("kmpath_handlerd", |
| 1667 | WQ_MEM_RECLAIM); |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1668 | if (!kmpath_handlerd) { |
| 1669 | DMERR("failed to create workqueue kmpath_handlerd"); |
| 1670 | destroy_workqueue(kmultipathd); |
| 1671 | dm_unregister_target(&multipath_target); |
| 1672 | kmem_cache_destroy(_mpio_cache); |
| 1673 | return -ENOMEM; |
| 1674 | } |
| 1675 | |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 1676 | DMINFO("version %u.%u.%u loaded", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1677 | multipath_target.version[0], multipath_target.version[1], |
| 1678 | multipath_target.version[2]); |
| 1679 | |
| 1680 | return r; |
| 1681 | } |
| 1682 | |
| 1683 | static void __exit dm_multipath_exit(void) |
| 1684 | { |
Chandra Seetharaman | bab7cfc | 2008-05-01 14:50:22 -0700 | [diff] [blame] | 1685 | destroy_workqueue(kmpath_handlerd); |
Alasdair G Kergon | c557308 | 2005-05-05 16:16:07 -0700 | [diff] [blame] | 1686 | destroy_workqueue(kmultipathd); |
| 1687 | |
Mikulas Patocka | 10d3bd0 | 2009-01-06 03:04:58 +0000 | [diff] [blame] | 1688 | dm_unregister_target(&multipath_target); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1689 | kmem_cache_destroy(_mpio_cache); |
| 1690 | } |
| 1691 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1692 | module_init(dm_multipath_init); |
| 1693 | module_exit(dm_multipath_exit); |
| 1694 | |
| 1695 | MODULE_DESCRIPTION(DM_NAME " multipath target"); |
| 1696 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); |
| 1697 | MODULE_LICENSE("GPL"); |