* This file is released under the GPL.
*/
-#include "dm.h"
+#include <linux/device-mapper.h>
+
#include "dm-path-selector.h"
-#include "dm-hw-handler.h"
-#include "dm-bio-list.h"
-#include "dm-bio-record.h"
+#include "dm-uevent.h"
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/workqueue.h>
+#include <scsi/scsi_dh.h>
#include <asm/atomic.h>
+#define DM_MSG_PREFIX "multipath"
#define MESG_STR(x) x, sizeof(x)
/* Path properties */
struct list_head list;
struct priority_group *pg; /* Owning PG */
+ unsigned is_active; /* Path status */
unsigned fail_count; /* Cumulative failure count */
- struct path path;
+ struct dm_path path;
+ struct work_struct deactivate_path;
+ struct work_struct activate_path;
};
#define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path)
spinlock_t lock;
- struct hw_handler hw_handler;
+ const char *hw_handler_name;
+ char *hw_handler_params;
unsigned nr_priority_groups;
struct list_head priority_groups;
unsigned pg_init_required; /* pg_init needs calling? */
unsigned queue_io; /* Must we queue all I/O? */
unsigned queue_if_no_path; /* Queue I/O if last path fails? */
unsigned saved_queue_if_no_path;/* Saved state during suspension */
+ unsigned pg_init_retries; /* Number of times to retry pg_init */
+ unsigned pg_init_count; /* Number of times pg_init called */
struct work_struct process_queued_ios;
- struct bio_list queued_ios;
+ struct list_head queued_ios;
unsigned queue_size;
struct work_struct trigger_event;
/*
- * We must use a mempool of mpath_io structs so that we
+ * We must use a mempool of dm_mpath_io structs so that we
* can resubmit bios on error.
*/
mempool_t *mpio_pool;
/*
* Context information attached to each bio we process.
*/
-struct mpath_io {
+struct dm_mpath_io {
struct pgpath *pgpath;
- struct dm_bio_details details;
+ size_t nr_bytes;
};
typedef int (*action_fn) (struct pgpath *pgpath);
#define MIN_IOS 256 /* Mempool size */
-static kmem_cache_t *_mpio_cache;
+static struct kmem_cache *_mpio_cache;
-struct workqueue_struct *kmultipathd;
-static void process_queued_ios(void *data);
-static void trigger_event(void *data);
+static struct workqueue_struct *kmultipathd, *kmpath_handlerd;
+static void process_queued_ios(struct work_struct *work);
+static void trigger_event(struct work_struct *work);
+static void activate_path(struct work_struct *work);
+static void deactivate_path(struct work_struct *work);
/*-----------------------------------------------
static struct pgpath *alloc_pgpath(void)
{
- struct pgpath *pgpath = kmalloc(sizeof(*pgpath), GFP_KERNEL);
+ struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL);
if (pgpath) {
- memset(pgpath, 0, sizeof(*pgpath));
- pgpath->path.is_active = 1;
+ pgpath->is_active = 1;
+ INIT_WORK(&pgpath->deactivate_path, deactivate_path);
+ INIT_WORK(&pgpath->activate_path, activate_path);
}
return pgpath;
}
-static inline void free_pgpath(struct pgpath *pgpath)
+static void free_pgpath(struct pgpath *pgpath)
{
kfree(pgpath);
}
+static void deactivate_path(struct work_struct *work)
+{
+ struct pgpath *pgpath =
+ container_of(work, struct pgpath, deactivate_path);
+
+ blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
+}
+
static struct priority_group *alloc_priority_group(void)
{
struct priority_group *pg;
- pg = kmalloc(sizeof(*pg), GFP_KERNEL);
- if (!pg)
- return NULL;
+ pg = kzalloc(sizeof(*pg), GFP_KERNEL);
- memset(pg, 0, sizeof(*pg));
- INIT_LIST_HEAD(&pg->pgpaths);
+ if (pg)
+ INIT_LIST_HEAD(&pg->pgpaths);
return pg;
}
static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti)
{
struct pgpath *pgpath, *tmp;
+ struct multipath *m = ti->private;
list_for_each_entry_safe(pgpath, tmp, pgpaths, list) {
list_del(&pgpath->list);
+ if (m->hw_handler_name)
+ scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev));
dm_put_device(ti, pgpath->path.dev);
free_pgpath(pgpath);
}
kfree(pg);
}
-static struct multipath *alloc_multipath(void)
+static struct multipath *alloc_multipath(struct dm_target *ti)
{
struct multipath *m;
- m = kmalloc(sizeof(*m), GFP_KERNEL);
+ m = kzalloc(sizeof(*m), GFP_KERNEL);
if (m) {
- memset(m, 0, sizeof(*m));
INIT_LIST_HEAD(&m->priority_groups);
+ INIT_LIST_HEAD(&m->queued_ios);
spin_lock_init(&m->lock);
m->queue_io = 1;
- INIT_WORK(&m->process_queued_ios, process_queued_ios, m);
- INIT_WORK(&m->trigger_event, trigger_event, m);
+ INIT_WORK(&m->process_queued_ios, process_queued_ios);
+ INIT_WORK(&m->trigger_event, trigger_event);
m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache);
if (!m->mpio_pool) {
kfree(m);
return NULL;
}
+ m->ti = ti;
+ ti->private = m;
}
return m;
static void free_multipath(struct multipath *m)
{
struct priority_group *pg, *tmp;
- struct hw_handler *hwh = &m->hw_handler;
list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) {
list_del(&pg->list);
free_priority_group(pg, m->ti);
}
- if (hwh->type) {
- hwh->type->destroy(hwh);
- dm_put_hw_handler(hwh->type);
- }
-
+ kfree(m->hw_handler_name);
+ kfree(m->hw_handler_params);
mempool_destroy(m->mpio_pool);
kfree(m);
}
static void __switch_pg(struct multipath *m, struct pgpath *pgpath)
{
- struct hw_handler *hwh = &m->hw_handler;
-
m->current_pg = pgpath->pg;
/* Must we initialise the PG first, and queue I/O till it's ready? */
- if (hwh->type && hwh->type->pg_init) {
+ if (m->hw_handler_name) {
m->pg_init_required = 1;
m->queue_io = 1;
} else {
m->pg_init_required = 0;
m->queue_io = 0;
}
+
+ m->pg_init_count = 0;
}
-static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg)
+static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg,
+ size_t nr_bytes)
{
- struct path *path;
+ struct dm_path *path;
- path = pg->ps.type->select_path(&pg->ps, &m->repeat_count);
+ path = pg->ps.type->select_path(&pg->ps, &m->repeat_count, nr_bytes);
if (!path)
return -ENXIO;
return 0;
}
-static void __choose_pgpath(struct multipath *m)
+static void __choose_pgpath(struct multipath *m, size_t nr_bytes)
{
struct priority_group *pg;
unsigned bypassed = 1;
if (m->next_pg) {
pg = m->next_pg;
m->next_pg = NULL;
- if (!__choose_path_in_pg(m, pg))
+ if (!__choose_path_in_pg(m, pg, nr_bytes))
return;
}
/* Don't change PG until it has no remaining paths */
- if (m->current_pg && !__choose_path_in_pg(m, m->current_pg))
+ if (m->current_pg && !__choose_path_in_pg(m, m->current_pg, nr_bytes))
return;
/*
list_for_each_entry(pg, &m->priority_groups, list) {
if (pg->bypassed == bypassed)
continue;
- if (!__choose_path_in_pg(m, pg))
+ if (!__choose_path_in_pg(m, pg, nr_bytes))
return;
}
} while (bypassed--);
m->current_pg = NULL;
}
-static int map_io(struct multipath *m, struct bio *bio, struct mpath_io *mpio,
- unsigned was_queued)
+/*
+ * Check whether bios must be queued in the device-mapper core rather
+ * than here in the target.
+ *
+ * m->lock must be held on entry.
+ *
+ * If m->queue_if_no_path and m->saved_queue_if_no_path hold the
+ * same value then we are not between multipath_presuspend()
+ * and multipath_resume() calls and we have no need to check
+ * for the DMF_NOFLUSH_SUSPENDING flag.
+ */
+static int __must_push_back(struct multipath *m)
+{
+ return (m->queue_if_no_path != m->saved_queue_if_no_path &&
+ dm_noflush_suspending(m->ti));
+}
+
+static int map_io(struct multipath *m, struct request *clone,
+ struct dm_mpath_io *mpio, unsigned was_queued)
{
- int r = 1;
+ int r = DM_MAPIO_REMAPPED;
+ size_t nr_bytes = blk_rq_bytes(clone);
unsigned long flags;
struct pgpath *pgpath;
+ struct block_device *bdev;
spin_lock_irqsave(&m->lock, flags);
/* Do we need to select a new pgpath? */
if (!m->current_pgpath ||
(!m->queue_io && (m->repeat_count && --m->repeat_count == 0)))
- __choose_pgpath(m);
+ __choose_pgpath(m, nr_bytes);
pgpath = m->current_pgpath;
if ((pgpath && m->queue_io) ||
(!pgpath && m->queue_if_no_path)) {
/* Queue for the daemon to resubmit */
- bio_list_add(&m->queued_ios, bio);
+ list_add_tail(&clone->queuelist, &m->queued_ios);
m->queue_size++;
if ((m->pg_init_required && !m->pg_init_in_progress) ||
!m->queue_io)
queue_work(kmultipathd, &m->process_queued_ios);
pgpath = NULL;
- r = 0;
- } else if (!pgpath)
- r = -EIO; /* Failed */
+ r = DM_MAPIO_SUBMITTED;
+ } else if (pgpath) {
+ bdev = pgpath->path.dev->bdev;
+ clone->q = bdev_get_queue(bdev);
+ clone->rq_disk = bdev->bd_disk;
+ } else if (__must_push_back(m))
+ r = DM_MAPIO_REQUEUE;
else
- bio->bi_bdev = pgpath->path.dev->bdev;
+ r = -EIO; /* Failed */
mpio->pgpath = pgpath;
+ mpio->nr_bytes = nr_bytes;
+
+ if (r == DM_MAPIO_REMAPPED && pgpath->pg->ps.type->start_io)
+ pgpath->pg->ps.type->start_io(&pgpath->pg->ps, &pgpath->path,
+ nr_bytes);
spin_unlock_irqrestore(&m->lock, flags);
{
int r;
unsigned long flags;
- struct bio *bio = NULL, *next;
- struct mpath_io *mpio;
+ struct dm_mpath_io *mpio;
union map_info *info;
+ struct request *clone, *n;
+ LIST_HEAD(cl);
spin_lock_irqsave(&m->lock, flags);
- bio = bio_list_get(&m->queued_ios);
+ list_splice_init(&m->queued_ios, &cl);
spin_unlock_irqrestore(&m->lock, flags);
- while (bio) {
- next = bio->bi_next;
- bio->bi_next = NULL;
+ list_for_each_entry_safe(clone, n, &cl, queuelist) {
+ list_del_init(&clone->queuelist);
- info = dm_get_mapinfo(bio);
+ info = dm_get_rq_mapinfo(clone);
mpio = info->ptr;
- r = map_io(m, bio, mpio, 1);
- if (r < 0)
- bio_endio(bio, bio->bi_size, r);
- else if (r == 1)
- generic_make_request(bio);
-
- bio = next;
+ r = map_io(m, clone, mpio, 1);
+ if (r < 0) {
+ mempool_free(mpio, m->mpio_pool);
+ dm_kill_unmapped_request(clone, r);
+ } else if (r == DM_MAPIO_REMAPPED)
+ dm_dispatch_request(clone);
+ else if (r == DM_MAPIO_REQUEUE) {
+ mempool_free(mpio, m->mpio_pool);
+ dm_requeue_unmapped_request(clone);
+ }
}
}
-static void process_queued_ios(void *data)
+static void process_queued_ios(struct work_struct *work)
{
- struct multipath *m = (struct multipath *) data;
- struct hw_handler *hwh = &m->hw_handler;
- struct pgpath *pgpath = NULL;
- unsigned init_required = 0, must_queue = 1;
+ struct multipath *m =
+ container_of(work, struct multipath, process_queued_ios);
+ struct pgpath *pgpath = NULL, *tmp;
+ unsigned must_queue = 1;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
goto out;
if (!m->current_pgpath)
- __choose_pgpath(m);
+ __choose_pgpath(m, 0);
pgpath = m->current_pgpath;
(!pgpath && !m->queue_if_no_path))
must_queue = 0;
- if (m->pg_init_required && !m->pg_init_in_progress) {
+ if (m->pg_init_required && !m->pg_init_in_progress && pgpath) {
+ m->pg_init_count++;
m->pg_init_required = 0;
- m->pg_init_in_progress = 1;
- init_required = 1;
+ list_for_each_entry(tmp, &pgpath->pg->pgpaths, list) {
+ if (queue_work(kmpath_handlerd, &tmp->activate_path))
+ m->pg_init_in_progress++;
+ }
}
-
out:
spin_unlock_irqrestore(&m->lock, flags);
-
- if (init_required)
- hwh->type->pg_init(hwh, pgpath->pg->bypassed, &pgpath->path);
-
if (!must_queue)
dispatch_queued_ios(m);
}
* An event is triggered whenever a path is taken out of use.
* Includes path failure and PG bypass.
*/
-static void trigger_event(void *data)
+static void trigger_event(struct work_struct *work)
{
- struct multipath *m = (struct multipath *) data;
+ struct multipath *m =
+ container_of(work, struct multipath, trigger_event);
dm_table_event(m->ti->table);
}
char *error;
};
-#define ESTR(s) ("dm-multipath: " s)
-
static int read_param(struct param *param, char *str, unsigned *v, char **error)
{
if (!str ||
unsigned ps_argc;
static struct param _params[] = {
- {0, 1024, ESTR("invalid number of path selector args")},
+ {0, 1024, "invalid number of path selector args"},
};
pst = dm_get_path_selector(shift(as));
if (!pst) {
- ti->error = ESTR("unknown path selector type");
+ ti->error = "unknown path selector type";
return -EINVAL;
}
r = read_param(_params, shift(as), &ps_argc, &ti->error);
- if (r)
+ if (r) {
+ dm_put_path_selector(pst);
+ return -EINVAL;
+ }
+
+ if (ps_argc > as->argc) {
+ dm_put_path_selector(pst);
+ ti->error = "not enough arguments for path selector";
return -EINVAL;
+ }
r = pst->create(&pg->ps, ps_argc, as->argv);
if (r) {
dm_put_path_selector(pst);
- ti->error = ESTR("path selector constructor failed");
+ ti->error = "path selector constructor failed";
return r;
}
{
int r;
struct pgpath *p;
+ struct multipath *m = ti->private;
/* we need at least a path arg */
if (as->argc < 1) {
- ti->error = ESTR("no device given");
- return NULL;
+ ti->error = "no device given";
+ return ERR_PTR(-EINVAL);
}
p = alloc_pgpath();
if (!p)
- return NULL;
+ return ERR_PTR(-ENOMEM);
r = dm_get_device(ti, shift(as), ti->begin, ti->len,
dm_table_get_mode(ti->table), &p->path.dev);
if (r) {
- ti->error = ESTR("error getting device");
+ ti->error = "error getting device";
goto bad;
}
+ if (m->hw_handler_name) {
+ struct request_queue *q = bdev_get_queue(p->path.dev->bdev);
+
+ r = scsi_dh_attach(q, m->hw_handler_name);
+ if (r == -EBUSY) {
+ /*
+ * Already attached to different hw_handler,
+ * try to reattach with correct one.
+ */
+ scsi_dh_detach(q);
+ r = scsi_dh_attach(q, m->hw_handler_name);
+ }
+
+ if (r < 0) {
+ ti->error = "error attaching hardware handler";
+ dm_put_device(ti, p->path.dev);
+ goto bad;
+ }
+
+ if (m->hw_handler_params) {
+ r = scsi_dh_set_params(q, m->hw_handler_params);
+ if (r < 0) {
+ ti->error = "unable to set hardware "
+ "handler parameters";
+ scsi_dh_detach(q);
+ dm_put_device(ti, p->path.dev);
+ goto bad;
+ }
+ }
+ }
+
r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error);
if (r) {
dm_put_device(ti, p->path.dev);
bad:
free_pgpath(p);
- return NULL;
+ return ERR_PTR(r);
}
static struct priority_group *parse_priority_group(struct arg_set *as,
- struct multipath *m,
- struct dm_target *ti)
+ struct multipath *m)
{
static struct param _params[] = {
- {1, 1024, ESTR("invalid number of paths")},
- {0, 1024, ESTR("invalid number of selector args")}
+ {1, 1024, "invalid number of paths"},
+ {0, 1024, "invalid number of selector args"}
};
int r;
unsigned i, nr_selector_args, nr_params;
struct priority_group *pg;
+ struct dm_target *ti = m->ti;
if (as->argc < 2) {
as->argc = 0;
- ti->error = ESTR("not enough priority group aruments");
- return NULL;
+ ti->error = "not enough priority group arguments";
+ return ERR_PTR(-EINVAL);
}
pg = alloc_priority_group();
if (!pg) {
- ti->error = ESTR("couldn't allocate priority group");
- return NULL;
+ ti->error = "couldn't allocate priority group";
+ return ERR_PTR(-ENOMEM);
}
pg->m = m;
struct pgpath *pgpath;
struct arg_set path_args;
- if (as->argc < nr_params)
+ if (as->argc < nr_params) {
+ ti->error = "not enough path parameters";
goto bad;
+ }
path_args.argc = nr_params;
path_args.argv = as->argv;
pgpath = parse_path(&path_args, &pg->ps, ti);
- if (!pgpath)
+ if (IS_ERR(pgpath)) {
+ r = PTR_ERR(pgpath);
goto bad;
+ }
pgpath->pg = pg;
list_add_tail(&pgpath->list, &pg->pgpaths);
bad:
free_priority_group(pg, ti);
- return NULL;
+ return ERR_PTR(r);
}
-static int parse_hw_handler(struct arg_set *as, struct multipath *m,
- struct dm_target *ti)
+static int parse_hw_handler(struct arg_set *as, struct multipath *m)
{
- int r;
- struct hw_handler_type *hwht;
unsigned hw_argc;
+ int ret;
+ struct dm_target *ti = m->ti;
static struct param _params[] = {
- {0, 1024, ESTR("invalid number of hardware handler args")},
+ {0, 1024, "invalid number of hardware handler args"},
};
- r = read_param(_params, shift(as), &hw_argc, &ti->error);
- if (r)
+ if (read_param(_params, shift(as), &hw_argc, &ti->error))
return -EINVAL;
if (!hw_argc)
return 0;
- hwht = dm_get_hw_handler(shift(as));
- if (!hwht) {
- ti->error = ESTR("unknown hardware handler type");
+ if (hw_argc > as->argc) {
+ ti->error = "not enough arguments for hardware handler";
return -EINVAL;
}
- r = hwht->create(&m->hw_handler, hw_argc - 1, as->argv);
- if (r) {
- dm_put_hw_handler(hwht);
- ti->error = ESTR("hardware handler constructor failed");
- return r;
+ m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL);
+ request_module("scsi_dh_%s", m->hw_handler_name);
+ if (scsi_dh_handler_exist(m->hw_handler_name) == 0) {
+ ti->error = "unknown hardware handler type";
+ ret = -EINVAL;
+ goto fail;
}
- m->hw_handler.type = hwht;
+ if (hw_argc > 1) {
+ char *p;
+ int i, j, len = 4;
+
+ for (i = 0; i <= hw_argc - 2; i++)
+ len += strlen(as->argv[i]) + 1;
+ p = m->hw_handler_params = kzalloc(len, GFP_KERNEL);
+ if (!p) {
+ ti->error = "memory allocation failed";
+ ret = -ENOMEM;
+ goto fail;
+ }
+ j = sprintf(p, "%d", hw_argc - 1);
+ for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1)
+ j = sprintf(p, "%s", as->argv[i]);
+ }
consume(as, hw_argc - 1);
return 0;
+fail:
+ kfree(m->hw_handler_name);
+ m->hw_handler_name = NULL;
+ return ret;
}
-static int parse_features(struct arg_set *as, struct multipath *m,
- struct dm_target *ti)
+static int parse_features(struct arg_set *as, struct multipath *m)
{
int r;
unsigned argc;
+ struct dm_target *ti = m->ti;
+ const char *param_name;
static struct param _params[] = {
- {0, 1, ESTR("invalid number of feature args")},
+ {0, 3, "invalid number of feature args"},
+ {1, 50, "pg_init_retries must be between 1 and 50"},
};
r = read_param(_params, shift(as), &argc, &ti->error);
if (!argc)
return 0;
- if (!strnicmp(shift(as), MESG_STR("queue_if_no_path")))
- return queue_if_no_path(m, 1, 0);
- else {
+ do {
+ param_name = shift(as);
+ argc--;
+
+ if (!strnicmp(param_name, MESG_STR("queue_if_no_path"))) {
+ r = queue_if_no_path(m, 1, 0);
+ continue;
+ }
+
+ if (!strnicmp(param_name, MESG_STR("pg_init_retries")) &&
+ (argc >= 1)) {
+ r = read_param(_params + 1, shift(as),
+ &m->pg_init_retries, &ti->error);
+ argc--;
+ continue;
+ }
+
ti->error = "Unrecognised multipath feature request";
- return -EINVAL;
- }
+ r = -EINVAL;
+ } while (argc && !r);
+
+ return r;
}
static int multipath_ctr(struct dm_target *ti, unsigned int argc,
{
/* target parameters */
static struct param _params[] = {
- {1, 1024, ESTR("invalid number of priority groups")},
- {1, 1024, ESTR("invalid initial priority group number")},
+ {1, 1024, "invalid number of priority groups"},
+ {1, 1024, "invalid initial priority group number"},
};
int r;
as.argc = argc;
as.argv = argv;
- m = alloc_multipath();
+ m = alloc_multipath(ti);
if (!m) {
- ti->error = ESTR("can't allocate multipath");
+ ti->error = "can't allocate multipath";
return -EINVAL;
}
- r = parse_features(&as, m, ti);
+ r = parse_features(&as, m);
if (r)
goto bad;
- r = parse_hw_handler(&as, m, ti);
+ r = parse_hw_handler(&as, m);
if (r)
goto bad;
while (as.argc) {
struct priority_group *pg;
- pg = parse_priority_group(&as, m, ti);
- if (!pg) {
- r = -EINVAL;
+ pg = parse_priority_group(&as, m);
+ if (IS_ERR(pg)) {
+ r = PTR_ERR(pg);
goto bad;
}
}
if (pg_count != m->nr_priority_groups) {
- ti->error = ESTR("priority group count mismatch");
+ ti->error = "priority group count mismatch";
r = -EINVAL;
goto bad;
}
- ti->private = m;
- m->ti = ti;
+ ti->num_flush_requests = 1;
return 0;
{
struct multipath *m = (struct multipath *) ti->private;
+ flush_workqueue(kmpath_handlerd);
flush_workqueue(kmultipathd);
+ flush_scheduled_work();
free_multipath(m);
}
/*
- * Map bios, recording original fields for later in case we have to resubmit
+ * Map cloned requests
*/
-static int multipath_map(struct dm_target *ti, struct bio *bio,
+static int multipath_map(struct dm_target *ti, struct request *clone,
union map_info *map_context)
{
int r;
- struct mpath_io *mpio;
+ struct dm_mpath_io *mpio;
struct multipath *m = (struct multipath *) ti->private;
- if (bio_barrier(bio))
- return -EOPNOTSUPP;
-
- mpio = mempool_alloc(m->mpio_pool, GFP_NOIO);
- dm_bio_record(&mpio->details, bio);
+ mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC);
+ if (!mpio)
+ /* ENOMEM, requeue */
+ return DM_MAPIO_REQUEUE;
+ memset(mpio, 0, sizeof(*mpio));
map_context->ptr = mpio;
- bio->bi_rw |= (1 << BIO_RW_FAILFAST);
- r = map_io(m, bio, mpio, 0);
- if (r < 0)
+ clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
+ r = map_io(m, clone, mpio, 0);
+ if (r < 0 || r == DM_MAPIO_REQUEUE)
mempool_free(mpio, m->mpio_pool);
return r;
spin_lock_irqsave(&m->lock, flags);
- if (!pgpath->path.is_active)
+ if (!pgpath->is_active)
goto out;
- DMWARN("dm-multipath: Failing path %s.", pgpath->path.dev->name);
+ DMWARN("Failing path %s.", pgpath->path.dev->name);
pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path);
- pgpath->path.is_active = 0;
+ pgpath->is_active = 0;
pgpath->fail_count++;
m->nr_valid_paths--;
if (pgpath == m->current_pgpath)
m->current_pgpath = NULL;
- queue_work(kmultipathd, &m->trigger_event);
+ dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti,
+ pgpath->path.dev->name, m->nr_valid_paths);
+
+ schedule_work(&m->trigger_event);
+ queue_work(kmultipathd, &pgpath->deactivate_path);
out:
spin_unlock_irqrestore(&m->lock, flags);
spin_lock_irqsave(&m->lock, flags);
- if (pgpath->path.is_active)
+ if (pgpath->is_active)
goto out;
- if (!pgpath->pg->ps.type) {
+ if (!pgpath->pg->ps.type->reinstate_path) {
DMWARN("Reinstate path not supported by path selector %s",
pgpath->pg->ps.type->name);
r = -EINVAL;
if (r)
goto out;
- pgpath->path.is_active = 1;
+ pgpath->is_active = 1;
- m->current_pgpath = NULL;
- if (!m->nr_valid_paths++ && m->queue_size)
+ if (!m->nr_valid_paths++ && m->queue_size) {
+ m->current_pgpath = NULL;
queue_work(kmultipathd, &m->process_queued_ios);
+ } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) {
+ if (queue_work(kmpath_handlerd, &pgpath->activate_path))
+ m->pg_init_in_progress++;
+ }
+
+ dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
+ pgpath->path.dev->name, m->nr_valid_paths);
- queue_work(kmultipathd, &m->trigger_event);
+ schedule_work(&m->trigger_event);
out:
spin_unlock_irqrestore(&m->lock, flags);
spin_unlock_irqrestore(&m->lock, flags);
- queue_work(kmultipathd, &m->trigger_event);
+ schedule_work(&m->trigger_event);
}
/*
}
spin_unlock_irqrestore(&m->lock, flags);
- queue_work(kmultipathd, &m->trigger_event);
+ schedule_work(&m->trigger_event);
return 0;
}
}
/*
- * pg_init must call this when it has completed its initialisation
+ * Should we retry pg_init immediately?
*/
-void dm_pg_init_complete(struct path *path, unsigned err_flags)
+static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath)
{
+ unsigned long flags;
+ int limit_reached = 0;
+
+ spin_lock_irqsave(&m->lock, flags);
+
+ if (m->pg_init_count <= m->pg_init_retries)
+ m->pg_init_required = 1;
+ else
+ limit_reached = 1;
+
+ spin_unlock_irqrestore(&m->lock, flags);
+
+ return limit_reached;
+}
+
+static void pg_init_done(void *data, int errors)
+{
+ struct dm_path *path = data;
struct pgpath *pgpath = path_to_pgpath(path);
struct priority_group *pg = pgpath->pg;
struct multipath *m = pg->m;
unsigned long flags;
- /* We insist on failing the path if the PG is already bypassed. */
- if (err_flags && pg->bypassed)
- err_flags |= MP_FAIL_PATH;
-
- if (err_flags & MP_FAIL_PATH)
+ /* device or driver problems */
+ switch (errors) {
+ case SCSI_DH_OK:
+ break;
+ case SCSI_DH_NOSYS:
+ if (!m->hw_handler_name) {
+ errors = 0;
+ break;
+ }
+ DMERR("Cannot failover device because scsi_dh_%s was not "
+ "loaded.", m->hw_handler_name);
+ /*
+ * Fail path for now, so we do not ping pong
+ */
fail_path(pgpath);
-
- if (err_flags & MP_BYPASS_PG)
+ break;
+ case SCSI_DH_DEV_TEMP_BUSY:
+ /*
+ * Probably doing something like FW upgrade on the
+ * controller so try the other pg.
+ */
bypass_pg(m, pg, 1);
+ break;
+ /* TODO: For SCSI_DH_RETRY we should wait a couple seconds */
+ case SCSI_DH_RETRY:
+ case SCSI_DH_IMM_RETRY:
+ case SCSI_DH_RES_TEMP_UNAVAIL:
+ if (pg_init_limit_reached(m, pgpath))
+ fail_path(pgpath);
+ errors = 0;
+ break;
+ default:
+ /*
+ * We probably do not want to fail the path for a device
+ * error, but this is what the old dm did. In future
+ * patches we can do more advanced handling.
+ */
+ fail_path(pgpath);
+ }
spin_lock_irqsave(&m->lock, flags);
- if (err_flags) {
- m->current_pgpath = NULL;
- m->current_pg = NULL;
- } else if (!m->pg_init_required)
+ if (errors) {
+ if (pgpath == m->current_pgpath) {
+ DMERR("Could not failover device. Error %d.", errors);
+ m->current_pgpath = NULL;
+ m->current_pg = NULL;
+ }
+ } else if (!m->pg_init_required) {
m->queue_io = 0;
+ pg->bypassed = 0;
+ }
- m->pg_init_in_progress = 0;
- queue_work(kmultipathd, &m->process_queued_ios);
+ m->pg_init_in_progress--;
+ if (!m->pg_init_in_progress)
+ queue_work(kmultipathd, &m->process_queued_ios);
spin_unlock_irqrestore(&m->lock, flags);
}
+static void activate_path(struct work_struct *work)
+{
+ struct pgpath *pgpath =
+ container_of(work, struct pgpath, activate_path);
+
+ scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev),
+ pg_init_done, &pgpath->path);
+}
+
/*
* end_io handling
*/
-static int do_end_io(struct multipath *m, struct bio *bio,
- int error, struct mpath_io *mpio)
+static int do_end_io(struct multipath *m, struct request *clone,
+ int error, struct dm_mpath_io *mpio)
{
- struct hw_handler *hwh = &m->hw_handler;
- unsigned err_flags = MP_FAIL_PATH; /* Default behavior */
+ /*
+ * We don't queue any clone request inside the multipath target
+ * during end I/O handling, since those clone requests don't have
+ * bio clones. If we queue them inside the multipath target,
+ * we need to make bio clones, that requires memory allocation.
+ * (See drivers/md/dm.c:end_clone_bio() about why the clone requests
+ * don't have bio clones.)
+ * Instead of queueing the clone request here, we queue the original
+ * request into dm core, which will remake a clone request and
+ * clone bios for it and resubmit it later.
+ */
+ int r = DM_ENDIO_REQUEUE;
unsigned long flags;
- if (!error)
+ if (!error && !clone->errors)
return 0; /* I/O complete */
- if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio))
- return error;
-
if (error == -EOPNOTSUPP)
return error;
- spin_lock_irqsave(&m->lock, flags);
- if (!m->nr_valid_paths) {
- if (!m->queue_if_no_path) {
- spin_unlock_irqrestore(&m->lock, flags);
- return -EIO;
- } else {
- spin_unlock_irqrestore(&m->lock, flags);
- goto requeue;
- }
- }
- spin_unlock_irqrestore(&m->lock, flags);
-
- if (hwh->type && hwh->type->error)
- err_flags = hwh->type->error(hwh, bio);
-
- if (mpio->pgpath) {
- if (err_flags & MP_FAIL_PATH)
- fail_path(mpio->pgpath);
+ if (mpio->pgpath)
+ fail_path(mpio->pgpath);
- if (err_flags & MP_BYPASS_PG)
- bypass_pg(m, mpio->pgpath->pg, 1);
- }
-
- if (err_flags & MP_ERROR_IO)
- return -EIO;
-
- requeue:
- dm_bio_restore(&mpio->details, bio);
-
- /* queue for the daemon to resubmit or fail */
spin_lock_irqsave(&m->lock, flags);
- bio_list_add(&m->queued_ios, bio);
- m->queue_size++;
- if (!m->queue_io)
- queue_work(kmultipathd, &m->process_queued_ios);
+ if (!m->nr_valid_paths && !m->queue_if_no_path && !__must_push_back(m))
+ r = -EIO;
spin_unlock_irqrestore(&m->lock, flags);
- return 1; /* io not complete */
+ return r;
}
-static int multipath_end_io(struct dm_target *ti, struct bio *bio,
+static int multipath_end_io(struct dm_target *ti, struct request *clone,
int error, union map_info *map_context)
{
- struct multipath *m = (struct multipath *) ti->private;
- struct mpath_io *mpio = (struct mpath_io *) map_context->ptr;
+ struct multipath *m = ti->private;
+ struct dm_mpath_io *mpio = map_context->ptr;
struct pgpath *pgpath = mpio->pgpath;
struct path_selector *ps;
int r;
- r = do_end_io(m, bio, error, mpio);
+ r = do_end_io(m, clone, error, mpio);
if (pgpath) {
ps = &pgpath->pg->ps;
if (ps->type->end_io)
- ps->type->end_io(ps, &pgpath->path);
+ ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes);
}
- if (r <= 0)
- mempool_free(mpio, m->mpio_pool);
+ mempool_free(mpio, m->mpio_pool);
return r;
}
int sz = 0;
unsigned long flags;
struct multipath *m = (struct multipath *) ti->private;
- struct hw_handler *hwh = &m->hw_handler;
struct priority_group *pg;
struct pgpath *p;
unsigned pg_num;
/* Features */
if (type == STATUSTYPE_INFO)
- DMEMIT("1 %u ", m->queue_size);
- else if (m->queue_if_no_path)
- DMEMIT("1 queue_if_no_path ");
- else
- DMEMIT("0 ");
+ DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count);
+ else {
+ DMEMIT("%u ", m->queue_if_no_path +
+ (m->pg_init_retries > 0) * 2);
+ if (m->queue_if_no_path)
+ DMEMIT("queue_if_no_path ");
+ if (m->pg_init_retries)
+ DMEMIT("pg_init_retries %u ", m->pg_init_retries);
+ }
- if (hwh->type && hwh->type->status)
- sz += hwh->type->status(hwh, type, result + sz, maxlen - sz);
- else if (!hwh->type || type == STATUSTYPE_INFO)
+ if (!m->hw_handler_name || type == STATUSTYPE_INFO)
DMEMIT("0 ");
else
- DMEMIT("1 %s ", hwh->type->name);
+ DMEMIT("1 %s ", m->hw_handler_name);
DMEMIT("%u ", m->nr_priority_groups);
list_for_each_entry(p, &pg->pgpaths, list) {
DMEMIT("%s %s %u ", p->path.dev->name,
- p->path.is_active ? "A" : "F",
+ p->is_active ? "A" : "F",
p->fail_count);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps,
r = dm_get_device(ti, argv[1], ti->begin, ti->len,
dm_table_get_mode(ti->table), &dev);
if (r) {
- DMWARN("dm-multipath message: error getting device %s",
+ DMWARN("message: error getting device %s",
argv[1]);
return -EINVAL;
}
return -EINVAL;
}
+static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
+ unsigned long arg)
+{
+ struct multipath *m = (struct multipath *) ti->private;
+ struct block_device *bdev = NULL;
+ fmode_t mode = 0;
+ unsigned long flags;
+ int r = 0;
+
+ spin_lock_irqsave(&m->lock, flags);
+
+ if (!m->current_pgpath)
+ __choose_pgpath(m, 0);
+
+ if (m->current_pgpath) {
+ bdev = m->current_pgpath->path.dev->bdev;
+ mode = m->current_pgpath->path.dev->mode;
+ }
+
+ if (m->queue_io)
+ r = -EAGAIN;
+ else if (!bdev)
+ r = -EIO;
+
+ spin_unlock_irqrestore(&m->lock, flags);
+
+ return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+}
+
+static int multipath_iterate_devices(struct dm_target *ti,
+ iterate_devices_callout_fn fn, void *data)
+{
+ struct multipath *m = ti->private;
+ struct priority_group *pg;
+ struct pgpath *p;
+ int ret = 0;
+
+ list_for_each_entry(pg, &m->priority_groups, list) {
+ list_for_each_entry(p, &pg->pgpaths, list) {
+ ret = fn(ti, p->path.dev, ti->begin, ti->len, data);
+ if (ret)
+ goto out;
+ }
+ }
+
+out:
+ return ret;
+}
+
+static int __pgpath_busy(struct pgpath *pgpath)
+{
+ struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
+
+ return dm_underlying_device_busy(q);
+}
+
+/*
+ * We return "busy", only when we can map I/Os but underlying devices
+ * are busy (so even if we map I/Os now, the I/Os will wait on
+ * the underlying queue).
+ * In other words, if we want to kill I/Os or queue them inside us
+ * due to map unavailability, we don't return "busy". Otherwise,
+ * dm core won't give us the I/Os and we can't do what we want.
+ */
+static int multipath_busy(struct dm_target *ti)
+{
+ int busy = 0, has_active = 0;
+ struct multipath *m = ti->private;
+ struct priority_group *pg;
+ struct pgpath *pgpath;
+ unsigned long flags;
+
+ spin_lock_irqsave(&m->lock, flags);
+
+ /* Guess which priority_group will be used at next mapping time */
+ if (unlikely(!m->current_pgpath && m->next_pg))
+ pg = m->next_pg;
+ else if (likely(m->current_pg))
+ pg = m->current_pg;
+ else
+ /*
+ * We don't know which pg will be used at next mapping time.
+ * We don't call __choose_pgpath() here to avoid to trigger
+ * pg_init just by busy checking.
+ * So we don't know whether underlying devices we will be using
+ * at next mapping time are busy or not. Just try mapping.
+ */
+ goto out;
+
+ /*
+ * If there is one non-busy active path at least, the path selector
+ * will be able to select it. So we consider such a pg as not busy.
+ */
+ busy = 1;
+ list_for_each_entry(pgpath, &pg->pgpaths, list)
+ if (pgpath->is_active) {
+ has_active = 1;
+
+ if (!__pgpath_busy(pgpath)) {
+ busy = 0;
+ break;
+ }
+ }
+
+ if (!has_active)
+ /*
+ * No active path in this pg, so this pg won't be used and
+ * the current_pg will be changed at next mapping time.
+ * We need to try mapping to determine it.
+ */
+ busy = 0;
+
+out:
+ spin_unlock_irqrestore(&m->lock, flags);
+
+ return busy;
+}
+
/*-----------------------------------------------------------------
* Module setup
*---------------------------------------------------------------*/
static struct target_type multipath_target = {
.name = "multipath",
- .version = {1, 0, 4},
+ .version = {1, 1, 0},
.module = THIS_MODULE,
.ctr = multipath_ctr,
.dtr = multipath_dtr,
- .map = multipath_map,
- .end_io = multipath_end_io,
+ .map_rq = multipath_map,
+ .rq_end_io = multipath_end_io,
.presuspend = multipath_presuspend,
.resume = multipath_resume,
.status = multipath_status,
.message = multipath_message,
+ .ioctl = multipath_ioctl,
+ .iterate_devices = multipath_iterate_devices,
+ .busy = multipath_busy,
};
static int __init dm_multipath_init(void)
int r;
/* allocate a slab for the dm_ios */
- _mpio_cache = kmem_cache_create("dm_mpath", sizeof(struct mpath_io),
- 0, 0, NULL, NULL);
+ _mpio_cache = KMEM_CACHE(dm_mpath_io, 0);
if (!_mpio_cache)
return -ENOMEM;
r = dm_register_target(&multipath_target);
if (r < 0) {
- DMERR("%s: register failed %d", multipath_target.name, r);
+ DMERR("register failed %d", r);
kmem_cache_destroy(_mpio_cache);
return -EINVAL;
}
kmultipathd = create_workqueue("kmpathd");
if (!kmultipathd) {
- DMERR("%s: failed to create workqueue kmpathd",
- multipath_target.name);
+ DMERR("failed to create workqueue kmpathd");
dm_unregister_target(&multipath_target);
kmem_cache_destroy(_mpio_cache);
return -ENOMEM;
}
- DMINFO("dm-multipath version %u.%u.%u loaded",
+ /*
+ * A separate workqueue is used to handle the device handlers
+ * to avoid overloading existing workqueue. Overloading the
+ * old workqueue would also create a bottleneck in the
+ * path of the storage hardware device activation.
+ */
+ kmpath_handlerd = create_singlethread_workqueue("kmpath_handlerd");
+ if (!kmpath_handlerd) {
+ DMERR("failed to create workqueue kmpath_handlerd");
+ destroy_workqueue(kmultipathd);
+ dm_unregister_target(&multipath_target);
+ kmem_cache_destroy(_mpio_cache);
+ return -ENOMEM;
+ }
+
+ DMINFO("version %u.%u.%u loaded",
multipath_target.version[0], multipath_target.version[1],
multipath_target.version[2]);
static void __exit dm_multipath_exit(void)
{
- int r;
-
+ destroy_workqueue(kmpath_handlerd);
destroy_workqueue(kmultipathd);
- r = dm_unregister_target(&multipath_target);
- if (r < 0)
- DMERR("%s: target unregister failed %d",
- multipath_target.name, r);
+ dm_unregister_target(&multipath_target);
kmem_cache_destroy(_mpio_cache);
}
-EXPORT_SYMBOL_GPL(dm_pg_init_complete);
-
module_init(dm_multipath_init);
module_exit(dm_multipath_exit);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff