#include <linux/workqueue.h>
#include <asm/atomic.h>
+#define DM_MSG_PREFIX "multipath"
#define MESG_STR(x) x, sizeof(x)
/* Path properties */
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)
#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;
}
{
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);
- m->mpio_pool = mempool_create(MIN_IOS, mempool_alloc_slab,
- mempool_free_slab, _mpio_cache);
+ 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 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;
}
+/*
+ * 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 bio *bio, struct mpath_io *mpio,
unsigned was_queued)
{
- int r = 1;
+ 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;
r = map_io(m, bio, mpio, 1);
if (r < 0)
bio_endio(bio, bio->bi_size, r);
- else if (r == 1)
+ else if (r == DM_MAPIO_REMAPPED)
generic_make_request(bio);
+ else if (r == DM_MAPIO_REQUEUE)
+ bio_endio(bio, bio->bi_size, -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;
* 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 = 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;
}
/* we need at least a path arg */
if (as->argc < 1) {
- ti->error = ESTR("no device given");
+ ti->error = "no device given";
return NULL;
}
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;
}
}
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");
+ ti->error = "not enough priority group aruments";
return NULL;
}
pg = alloc_priority_group();
if (!pg) {
- ti->error = ESTR("couldn't allocate priority group");
+ ti->error = "couldn't allocate priority group";
return NULL;
}
pg->m = m;
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, 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);
hwht = dm_get_hw_handler(shift(as));
if (!hwht) {
- ti->error = ESTR("unknown hardware handler type");
+ ti->error = "unknown hardware handler type";
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");
+ ti->error = "hardware handler constructor failed";
return r;
}
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;
static struct param _params[] = {
- {0, 1, ESTR("invalid number of feature args")},
+ {0, 1, "invalid number of feature args"},
};
r = read_param(_params, shift(as), &argc, &ti->error);
{
/* 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;
}
- 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;
}
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;
-
return 0;
bad:
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->path.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;
/*
* 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;
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,
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;
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, 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)
return -ENOMEM;
}
- DMINFO("dm-multipath version %u.%u.%u loaded",
+ DMINFO("version %u.%u.%u loaded",
multipath_target.version[0], multipath_target.version[1],
multipath_target.version[2]);
git://git.onelab.eu / linux-2.6.git / blobdiff