dm mpath: switch to using bitops for state flags (518257b1) · Commits · e / devices / android_kernel_teracube_2e

drivers/md/dm-mpath.c

+75 −56

Original line number	Diff line number	Diff line
		@@ -83,13 +83,7 @@ struct multipath {
		struct priority_group *current_pg;
		struct priority_group next_pg; / Switch to this PG if set */

		bool queue_io:1; /* Must we queue all I/O? */
		bool queue_if_no_path:1; /* Queue I/O if last path fails? */
		bool saved_queue_if_no_path:1; /* Saved state during suspension */
		bool retain_attached_hw_handler:1; /* If there's already a hw_handler present, don't change it. */
		bool pg_init_disabled:1; /* pg_init is not currently allowed */
		bool pg_init_required:1; /* pg_init needs calling? */
		bool pg_init_delay_retry:1; /* Delay pg_init retry? */
		unsigned long flags; /* Multipath state flags */

		unsigned pg_init_retries; /* Number of times to retry pg_init */
		unsigned pg_init_count; /* Number of times pg_init called */
		@@ -122,6 +116,17 @@ static struct workqueue_struct kmultipathd, kmpath_handlerd;
		static void trigger_event(struct work_struct *work);
		static void activate_path(struct work_struct *work);

		/*-----------------------------------------------
		* Multipath state flags.
		-----------------------------------------------/

		#define MPATHF_QUEUE_IO 0 /* Must we queue all I/O? */
		#define MPATHF_QUEUE_IF_NO_PATH 1 /* Queue I/O if last path fails? */
		#define MPATHF_SAVED_QUEUE_IF_NO_PATH 2 /* Saved state during suspension */
		#define MPATHF_RETAIN_ATTACHED_HW_HANDLER 3 /* If there's already a hw_handler present, don't change it. */
		#define MPATHF_PG_INIT_DISABLED 4 /* pg_init is not currently allowed */
		#define MPATHF_PG_INIT_REQUIRED 5 /* pg_init needs calling? */
		#define MPATHF_PG_INIT_DELAY_RETRY 6 /* Delay pg_init retry? */

		/*-----------------------------------------------
		* Allocation routines
		@@ -189,7 +194,7 @@ static struct multipath alloc_multipath(struct dm_target ti, bool use_blk_mq)
		if (m) {
		INIT_LIST_HEAD(&m->priority_groups);
		spin_lock_init(&m->lock);
		m->queue_io = true;
		set_bit(MPATHF_QUEUE_IO, &m->flags);
		m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT;
		INIT_WORK(&m->trigger_event, trigger_event);
		init_waitqueue_head(&m->pg_init_wait);
		@@ -274,17 +279,17 @@ static int __pg_init_all_paths(struct multipath *m)
		struct pgpath *pgpath;
		unsigned long pg_init_delay = 0;

		if (m->pg_init_in_progress \|\| m->pg_init_disabled)
		if (m->pg_init_in_progress \|\| test_bit(MPATHF_PG_INIT_DISABLED, &m->flags))
		return 0;

		m->pg_init_count++;
		m->pg_init_required = false;
		clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);

		/* Check here to reset pg_init_required */
		if (!m->current_pg)
		return 0;

		if (m->pg_init_delay_retry)
		if (test_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags))
		pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ?
		m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS);
		list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) {
		@@ -304,11 +309,11 @@ static void __switch_pg(struct multipath m, struct pgpath pgpath)

		/* Must we initialise the PG first, and queue I/O till it's ready? */
		if (m->hw_handler_name) {
		m->pg_init_required = true;
		m->queue_io = true;
		set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
		set_bit(MPATHF_QUEUE_IO, &m->flags);
		} else {
		m->pg_init_required = false;
		m->queue_io = false;
		clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
		clear_bit(MPATHF_QUEUE_IO, &m->flags);
		}

		m->pg_init_count = 0;
		@@ -337,7 +342,7 @@ static void __choose_pgpath(struct multipath *m, size_t nr_bytes)
		bool bypassed = true;

		if (!m->nr_valid_paths) {
		m->queue_io = false;
		clear_bit(MPATHF_QUEUE_IO, &m->flags);
		goto failed;
		}

		@@ -365,7 +370,7 @@ static void __choose_pgpath(struct multipath *m, size_t nr_bytes)
		continue;
		if (!__choose_path_in_pg(m, pg, nr_bytes)) {
		if (!bypassed)
		m->pg_init_delay_retry = true;
		set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);
		return;
		}
		}
		@@ -389,8 +394,9 @@ static void __choose_pgpath(struct multipath *m, size_t nr_bytes)
		*/
		static int __must_push_back(struct multipath *m)
		{
		return (m->queue_if_no_path \|\|
		(m->queue_if_no_path != m->saved_queue_if_no_path &&
		return (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) \|\|
		((test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) !=
		test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)) &&
		dm_noflush_suspending(m->ti)));
		}

		@@ -411,7 +417,7 @@ static int __multipath_map(struct dm_target ti, struct request clone,
		spin_lock_irq(&m->lock);

		/* Do we need to select a new pgpath? */
		if (!m->current_pgpath \|\| !m->queue_io)
		if (!m->current_pgpath \|\| !test_bit(MPATHF_QUEUE_IO, &m->flags))
		__choose_pgpath(m, nr_bytes);

		pgpath = m->current_pgpath;
		@@ -420,7 +426,8 @@ static int __multipath_map(struct dm_target ti, struct request clone,
		if (!__must_push_back(m))
		r = -EIO; /* Failed */
		goto out_unlock;
		} else if (m->queue_io \|\| m->pg_init_required) {
		} else if (test_bit(MPATHF_QUEUE_IO, &m->flags) \|\|
		test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
		__pg_init_all_paths(m);
		goto out_unlock;
		}
		@@ -503,11 +510,22 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,

		spin_lock_irqsave(&m->lock, flags);

		if (save_old_value)
		m->saved_queue_if_no_path = m->queue_if_no_path;
		if (save_old_value) {
		if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
		set_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
		else
		clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
		} else {
		if (queue_if_no_path)
		set_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
		else
		m->saved_queue_if_no_path = queue_if_no_path;
		m->queue_if_no_path = queue_if_no_path;
		clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
		}
		if (queue_if_no_path)
		set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
		else
		clear_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);

		spin_unlock_irqrestore(&m->lock, flags);

		if (!queue_if_no_path)
		@@ -600,10 +618,10 @@ static struct pgpath parse_path(struct dm_arg_set as, struct path_selector *ps
		goto bad;
		}

		if (m->retain_attached_hw_handler \|\| m->hw_handler_name)
		if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags) \|\| m->hw_handler_name)
		q = bdev_get_queue(p->path.dev->bdev);

		if (m->retain_attached_hw_handler) {
		if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) {
		retain:
		attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
		if (attached_handler_name) {
		@@ -808,7 +826,7 @@ static int parse_features(struct dm_arg_set as, struct multipath m)
		}

		if (!strcasecmp(arg_name, "retain_attached_hw_handler")) {
		m->retain_attached_hw_handler = true;
		set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags);
		continue;
		}

		@@ -944,20 +962,16 @@ static void multipath_wait_for_pg_init_completion(struct multipath *m)

		static void flush_multipath_work(struct multipath *m)
		{
		unsigned long flags;

		spin_lock_irqsave(&m->lock, flags);
		m->pg_init_disabled = true;
		spin_unlock_irqrestore(&m->lock, flags);
		set_bit(MPATHF_PG_INIT_DISABLED, &m->flags);
		smp_mb__after_atomic();

		flush_workqueue(kmpath_handlerd);
		multipath_wait_for_pg_init_completion(m);
		flush_workqueue(kmultipathd);
		flush_work(&m->trigger_event);

		spin_lock_irqsave(&m->lock, flags);
		m->pg_init_disabled = false;
		spin_unlock_irqrestore(&m->lock, flags);
		clear_bit(MPATHF_PG_INIT_DISABLED, &m->flags);
		smp_mb__after_atomic();
		}

		static void multipath_dtr(struct dm_target *ti)
		@@ -1152,8 +1166,8 @@ static bool pg_init_limit_reached(struct multipath m, struct pgpath pgpath)

		spin_lock_irqsave(&m->lock, flags);

		if (m->pg_init_count <= m->pg_init_retries && !m->pg_init_disabled)
		m->pg_init_required = true;
		if (m->pg_init_count <= m->pg_init_retries && !test_bit(MPATHF_PG_INIT_DISABLED, &m->flags))
		set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
		else
		limit_reached = true;

		@@ -1219,19 +1233,23 @@ static void pg_init_done(void *data, int errors)
		m->current_pgpath = NULL;
		m->current_pg = NULL;
		}
		} else if (!m->pg_init_required)
		} else if (!test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
		pg->bypassed = false;

		if (--m->pg_init_in_progress)
		/* Activations of other paths are still on going */
		goto out;

		if (m->pg_init_required) {
		m->pg_init_delay_retry = delay_retry;
		if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
		if (delay_retry)
		set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);
		else
		clear_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);

		if (__pg_init_all_paths(m))
		goto out;
		}
		m->queue_io = false;
		clear_bit(MPATHF_QUEUE_IO, &m->flags);

		/*
		* Wake up any thread waiting to suspend.
		@@ -1300,7 +1318,7 @@ static int do_end_io(struct multipath m, struct request clone,

		spin_lock_irqsave(&m->lock, flags);
		if (!m->nr_valid_paths) {
		if (!m->queue_if_no_path) {
		if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
		if (!__must_push_back(m))
		r = -EIO;
		} else {
		@@ -1364,11 +1382,12 @@ static void multipath_postsuspend(struct dm_target *ti)
		static void multipath_resume(struct dm_target *ti)
		{
		struct multipath *m = ti->private;
		unsigned long flags;

		spin_lock_irqsave(&m->lock, flags);
		m->queue_if_no_path = m->saved_queue_if_no_path;
		spin_unlock_irqrestore(&m->lock, flags);
		if (test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags))
		set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
		else
		clear_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
		smp_mb__after_atomic();
		}

		/*
		@@ -1402,19 +1421,19 @@ static void multipath_status(struct dm_target *ti, status_type_t type,

		/* Features */
		if (type == STATUSTYPE_INFO)
		DMEMIT("2 %u %u ", m->queue_io, m->pg_init_count);
		DMEMIT("2 %u %u ", test_bit(MPATHF_QUEUE_IO, &m->flags), m->pg_init_count);
		else {
		DMEMIT("%u ", m->queue_if_no_path +
		DMEMIT("%u ", test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) +
		(m->pg_init_retries > 0) * 2 +
		(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 +
		m->retain_attached_hw_handler);
		if (m->queue_if_no_path)
		test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags));
		if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
		DMEMIT("queue_if_no_path ");
		if (m->pg_init_retries)
		DMEMIT("pg_init_retries %u ", m->pg_init_retries);
		if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT)
		DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs);
		if (m->retain_attached_hw_handler)
		if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags))
		DMEMIT("retain_attached_hw_handler ");
		}

		@@ -1572,7 +1591,7 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
		__choose_pgpath(m, 0);

		if (m->current_pgpath) {
		if (!m->queue_io) {
		if (!test_bit(MPATHF_QUEUE_IO, &m->flags)) {
		*bdev = m->current_pgpath->path.dev->bdev;
		*mode = m->current_pgpath->path.dev->mode;
		r = 0;
		@@ -1582,7 +1601,7 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
		}
		} else {
		/* No path is available */
		if (m->queue_if_no_path)
		if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
		r = -ENOTCONN;
		else
		r = -EIO;
		@@ -1596,7 +1615,7 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
		/* Path status changed, redo selection */
		__choose_pgpath(m, 0);
		}
		if (m->pg_init_required)
		if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
		__pg_init_all_paths(m);
		spin_unlock_irqrestore(&m->lock, flags);
		dm_table_run_md_queue_async(m->ti->table);
		@@ -1657,7 +1676,7 @@ static int multipath_busy(struct dm_target *ti)

		/* pg_init in progress or no paths available */
		if (m->pg_init_in_progress \|\|
		(!m->nr_valid_paths && m->queue_if_no_path)) {
		(!m->nr_valid_paths && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))) {
		busy = true;
		goto out;
		}