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path: root/drivers/md/dm-mpath.c
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Diffstat (limited to 'drivers/md/dm-mpath.c')
-rw-r--r--drivers/md/dm-mpath.c153
1 files changed, 104 insertions, 49 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 93f701ea87bc..3aa013506967 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -31,7 +31,7 @@ struct pgpath {
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)
@@ -101,11 +101,11 @@ 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 void process_queued_ios(struct work_struct *work);
+static void trigger_event(struct work_struct *work);
/*-----------------------------------------------
@@ -114,12 +114,10 @@ static void trigger_event(void *data);
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;
}
@@ -133,12 +131,10 @@ 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;
}
@@ -168,23 +164,24 @@ static void free_priority_group(struct priority_group *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;
@@ -232,7 +229,7 @@ static void __switch_pg(struct multipath *m, struct pgpath *pgpath)
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)
@@ -285,10 +282,27 @@ failed:
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;
@@ -313,11 +327,13 @@ static int map_io(struct multipath *m, struct bio *bio, struct mpath_io *mpio,
!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;
@@ -375,16 +391,19 @@ static void dispatch_queued_ios(struct multipath *m)
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;
@@ -424,9 +443,10 @@ out:
* 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);
}
@@ -557,8 +577,7 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
}
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"},
@@ -568,6 +587,7 @@ static struct priority_group *parse_priority_group(struct arg_set *as,
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;
@@ -624,12 +644,12 @@ static struct priority_group *parse_priority_group(struct arg_set *as,
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"},
@@ -661,11 +681,11 @@ static int parse_hw_handler(struct arg_set *as, struct multipath *m,
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, "invalid number of feature args"},
@@ -704,19 +724,17 @@ 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;
@@ -732,7 +750,7 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
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;
@@ -752,8 +770,6 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
goto bad;
}
- ti->private = m;
-
return 0;
bad:
@@ -788,7 +804,7 @@ static int multipath_map(struct dm_target *ti, struct bio *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;
@@ -962,7 +978,7 @@ static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed)
/*
* 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;
@@ -1012,7 +1028,10 @@ static int do_end_io(struct multipath *m, struct bio *bio,
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 {
@@ -1047,7 +1066,7 @@ static int do_end_io(struct multipath *m, struct bio *bio,
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,
@@ -1065,7 +1084,7 @@ 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;
@@ -1266,12 +1285,47 @@ error:
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,
@@ -1281,6 +1335,7 @@ static struct target_type multipath_target = {
.resume = multipath_resume,
.status = multipath_status,
.message = multipath_message,
+ .ioctl = multipath_ioctl,
};
static int __init dm_multipath_init(void)
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-06 01:23:39 +0000