#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>
struct priority_group *pg; /* Owning PG */
unsigned fail_count; /* Cumulative failure count */
- struct path path;
+ struct dm_path path;
};
#define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path)
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 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;
};
#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 void process_queued_ios(struct work_struct *work);
+static void trigger_event(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));
+ if (pgpath)
pgpath->path.is_active = 1;
- }
return pgpath;
}
-static inline void free_pgpath(struct pgpath *pgpath)
+static void free_pgpath(struct pgpath *pgpath)
{
kfree(pgpath);
}
{
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;
}
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);
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;
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)
{
- struct path *path;
+ struct dm_path *path;
path = pg->ps.type->select_path(&pg->ps, &m->repeat_count);
if (!path)
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)
{
- int r = 1;
+ 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 bio *bio,
+ struct dm_mpath_io *mpio, unsigned was_queued)
+{
+ int r = DM_MAPIO_REMAPPED;
unsigned long flags;
struct pgpath *pgpath;
!m->queue_io)
queue_work(kmultipathd, &m->process_queued_ios);
pgpath = NULL;
- r = 0;
- } else if (!pgpath)
- r = -EIO; /* Failed */
- else
+ r = DM_MAPIO_SUBMITTED;
+ } else if (pgpath)
bio->bi_bdev = pgpath->path.dev->bdev;
+ else if (__must_push_back(m))
+ r = DM_MAPIO_REQUEUE;
+ else
+ r = -EIO; /* Failed */
mpio->pgpath = pgpath;
int r;
unsigned long flags;
struct bio *bio = NULL, *next;
- struct mpath_io *mpio;
+ struct dm_mpath_io *mpio;
union map_info *info;
spin_lock_irqsave(&m->lock, flags);
r = map_io(m, bio, mpio, 1);
if (r < 0)
- bio_endio(bio, bio->bi_size, r);
- else if (r == 1)
+ bio_endio(bio, r);
+ else if (r == DM_MAPIO_REMAPPED)
generic_make_request(bio);
+ else if (r == DM_MAPIO_REQUEUE)
+ bio_endio(bio, -EIO);
bio = next;
}
}
-static void process_queued_ios(void *data)
+static void process_queued_ios(struct work_struct *work)
{
- struct multipath *m = (struct multipath *) data;
+ struct multipath *m =
+ container_of(work, struct multipath, process_queued_ios);
struct hw_handler *hwh = &m->hw_handler;
struct pgpath *pgpath = NULL;
unsigned init_required = 0, must_queue = 1;
must_queue = 0;
if (m->pg_init_required && !m->pg_init_in_progress) {
+ m->pg_init_count++;
m->pg_init_required = 0;
m->pg_init_in_progress = 1;
init_required = 1;
* 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);
}
}
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, "invalid number of paths"},
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;
return NULL;
}
-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;
+ struct dm_target *ti = m->ti;
static struct param _params[] = {
{0, 1024, "invalid number of hardware handler args"},
return -EINVAL;
}
+ m->hw_handler.md = dm_table_get_md(ti->table);
+ dm_put(m->hw_handler.md);
+
r = hwht->create(&m->hw_handler, hw_argc - 1, as->argv);
if (r) {
dm_put_hw_handler(hwht);
return 0;
}
-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, "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,
as.argc = argc;
as.argv = argv;
- m = alloc_multipath();
+ m = alloc_multipath(ti);
if (!m) {
ti->error = "can't allocate multipath";
return -EINVAL;
}
- m->ti = ti;
-
- 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);
+ pg = parse_priority_group(&as, m);
if (!pg) {
r = -EINVAL;
goto bad;
goto bad;
}
- ti->private = m;
-
return 0;
bad:
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);
map_context->ptr = mpio;
bio->bi_rw |= (1 << BIO_RW_FAILFAST);
r = map_io(m, bio, mpio, 0);
- if (r < 0)
+ if (r < 0 || r == DM_MAPIO_REQUEUE)
mempool_free(mpio, m->mpio_pool);
return r;
if (pgpath == m->current_pgpath)
m->current_pgpath = NULL;
+ dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti,
+ pgpath->path.dev->name, m->nr_valid_paths);
+
queue_work(kmultipathd, &m->trigger_event);
out:
if (!m->nr_valid_paths++ && m->queue_size)
queue_work(kmultipathd, &m->process_queued_ios);
+ dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
+ pgpath->path.dev->name, m->nr_valid_paths);
+
queue_work(kmultipathd, &m->trigger_event);
out:
return 0;
}
+/*
+ * Should we retry pg_init immediately?
+ */
+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;
+}
+
/*
* pg_init must call this when it has completed its initialisation
*/
-void dm_pg_init_complete(struct path *path, unsigned err_flags)
+void dm_pg_init_complete(struct dm_path *path, unsigned err_flags)
{
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)
+ /*
+ * If requested, retry pg_init until maximum number of retries exceeded.
+ * If retry not requested and PG already bypassed, always fail the path.
+ */
+ if (err_flags & MP_RETRY) {
+ if (pg_init_limit_reached(m, pgpath))
+ err_flags |= MP_FAIL_PATH;
+ } else if (err_flags && pg->bypassed)
err_flags |= MP_FAIL_PATH;
if (err_flags & MP_FAIL_PATH)
bypass_pg(m, pg, 1);
spin_lock_irqsave(&m->lock, flags);
- if (err_flags) {
+ if (err_flags & ~MP_RETRY) {
m->current_pgpath = NULL;
m->current_pg = NULL;
} else if (!m->pg_init_required)
* end_io handling
*/
static int do_end_io(struct multipath *m, struct bio *bio,
- int error, struct mpath_io *mpio)
+ int error, struct dm_mpath_io *mpio)
{
struct hw_handler *hwh = &m->hw_handler;
unsigned err_flags = MP_FAIL_PATH; /* Default behavior */
spin_lock_irqsave(&m->lock, flags);
if (!m->nr_valid_paths) {
- if (!m->queue_if_no_path) {
+ if (__must_push_back(m)) {
+ spin_unlock_irqrestore(&m->lock, flags);
+ return DM_ENDIO_REQUEUE;
+ } else if (!m->queue_if_no_path) {
spin_unlock_irqrestore(&m->lock, flags);
return -EIO;
} else {
queue_work(kmultipathd, &m->process_queued_ios);
spin_unlock_irqrestore(&m->lock, flags);
- return 1; /* io not complete */
+ return DM_ENDIO_INCOMPLETE; /* io not complete */
}
static int multipath_end_io(struct dm_target *ti, struct bio *bio,
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;
if (ps->type->end_io)
ps->type->end_io(ps, &pgpath->path);
}
- if (r <= 0)
+ if (r != DM_ENDIO_INCOMPLETE)
mempool_free(mpio, m->mpio_pool);
return r;
/* 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);
return -EINVAL;
}
+static int multipath_ioctl(struct dm_target *ti, struct inode *inode,
+ struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ struct multipath *m = (struct multipath *) ti->private;
+ struct block_device *bdev = NULL;
+ unsigned long flags;
+ struct file fake_file = {};
+ struct dentry fake_dentry = {};
+ int r = 0;
+
+ fake_file.f_path.dentry = &fake_dentry;
+
+ spin_lock_irqsave(&m->lock, flags);
+
+ if (!m->current_pgpath)
+ __choose_pgpath(m);
+
+ if (m->current_pgpath) {
+ bdev = m->current_pgpath->path.dev->bdev;
+ fake_dentry.d_inode = bdev->bd_inode;
+ fake_file.f_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->bd_inode, &fake_file,
+ bdev->bd_disk, cmd, arg);
+}
+
/*-----------------------------------------------------------------
* Module setup
*---------------------------------------------------------------*/
static struct target_type multipath_target = {
.name = "multipath",
- .version = {1, 0, 4},
+ .version = {1, 0, 5},
.module = THIS_MODULE,
.ctr = multipath_ctr,
.dtr = multipath_dtr,
.resume = multipath_resume,
.status = multipath_status,
.message = multipath_message,
+ .ioctl = multipath_ioctl,
};
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;
r = dm_unregister_target(&multipath_target);
if (r < 0)
- DMERR("%s: target unregister failed %d",
- multipath_target.name, r);
+ DMERR("target unregister failed %d", r);
kmem_cache_destroy(_mpio_cache);
}
projects / linux-2.6-omap-h63xx.git / blobdiff