[PATCH] md: Set/get state of array via sysfs (9e653b63) · Commits · 戴 / test

Documentation/md.txt

+39 −0

Original line number	Diff line number	Diff line
		@@ -216,6 +216,45 @@ All md devices contain:
		period as a number of seconds. The default is 200msec (0.200).
		Writing a value of 0 disables safemode.

		array_state
		This file contains a single word which describes the current
		state of the array. In many cases, the state can be set by
		writing the word for the desired state, however some states
		cannot be explicitly set, and some transitions are not allowed.

		clear
		No devices, no size, no level
		Writing is equivalent to STOP_ARRAY ioctl
		inactive
		May have some settings, but array is not active
		all IO results in error
		When written, doesn't tear down array, but just stops it
		suspended (not supported yet)
		All IO requests will block. The array can be reconfigured.
		Writing this, if accepted, will block until array is quiessent
		readonly
		no resync can happen. no superblocks get written.
		write requests fail
		read-auto
		like readonly, but behaves like 'clean' on a write request.

		clean - no pending writes, but otherwise active.
		When written to inactive array, starts without resync
		If a write request arrives then
		if metadata is known, mark 'dirty' and switch to 'active'.
		if not known, block and switch to write-pending
		If written to an active array that has pending writes, then fails.
		active
		fully active: IO and resync can be happening.
		When written to inactive array, starts with resync

		write-pending
		clean, but writes are blocked waiting for 'active' to be written.

		active-idle
		like active, but no writes have been seen for a while (safe_mode_delay).


		sync_speed_min
		sync_speed_max
		This are similar to /proc/sys/dev/raid/speed_limit_{min,max}

drivers/md/md.c

+188 −9

Original line number	Diff line number	Diff line
		@@ -2185,6 +2185,176 @@ chunk_size_store(mddev_t mddev, const char buf, size_t len)
		static struct md_sysfs_entry md_chunk_size =
		__ATTR(chunk_size, 0644, chunk_size_show, chunk_size_store);

		/*
		* The array state can be:
		*
		* clear
		* No devices, no size, no level
		* Equivalent to STOP_ARRAY ioctl
		* inactive
		* May have some settings, but array is not active
		* all IO results in error
		* When written, doesn't tear down array, but just stops it
		* suspended (not supported yet)
		* All IO requests will block. The array can be reconfigured.
		* Writing this, if accepted, will block until array is quiessent
		* readonly
		* no resync can happen. no superblocks get written.
		* write requests fail
		* read-auto
		* like readonly, but behaves like 'clean' on a write request.
		*
		* clean - no pending writes, but otherwise active.
		* When written to inactive array, starts without resync
		* If a write request arrives then
		* if metadata is known, mark 'dirty' and switch to 'active'.
		* if not known, block and switch to write-pending
		* If written to an active array that has pending writes, then fails.
		* active
		* fully active: IO and resync can be happening.
		* When written to inactive array, starts with resync
		*
		* write-pending
		* clean, but writes are blocked waiting for 'active' to be written.
		*
		* active-idle
		* like active, but no writes have been seen for a while (100msec).
		*
		*/
		enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
		write_pending, active_idle, bad_word};
		char *array_states[] = {
		"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
		"write-pending", "active-idle", NULL };

		static int match_word(const char word, char *list)
		{
		int n;
		for (n=0; list[n]; n++)
		if (cmd_match(word, list[n]))
		break;
		return n;
		}

		static ssize_t
		array_state_show(mddev_t mddev, char page)
		{
		enum array_state st = inactive;

		if (mddev->pers)
		switch(mddev->ro) {
		case 1:
		st = readonly;
		break;
		case 2:
		st = read_auto;
		break;
		case 0:
		if (mddev->in_sync)
		st = clean;
		else if (mddev->safemode)
		st = active_idle;
		else
		st = active;
		}
		else {
		if (list_empty(&mddev->disks) &&
		mddev->raid_disks == 0 &&
		mddev->size == 0)
		st = clear;
		else
		st = inactive;
		}
		return sprintf(page, "%s\n", array_states[st]);
		}

		static int do_md_stop(mddev_t * mddev, int ro);
		static int do_md_run(mddev_t * mddev);
		static int restart_array(mddev_t *mddev);

		static ssize_t
		array_state_store(mddev_t mddev, const char buf, size_t len)
		{
		int err = -EINVAL;
		enum array_state st = match_word(buf, array_states);
		switch(st) {
		case bad_word:
		break;
		case clear:
		/* stopping an active array */
		if (mddev->pers) {
		if (atomic_read(&mddev->active) > 1)
		return -EBUSY;
		err = do_md_stop(mddev, 0);
		}
		break;
		case inactive:
		/* stopping an active array */
		if (mddev->pers) {
		if (atomic_read(&mddev->active) > 1)
		return -EBUSY;
		err = do_md_stop(mddev, 2);
		}
		break;
		case suspended:
		break; /* not supported yet */
		case readonly:
		if (mddev->pers)
		err = do_md_stop(mddev, 1);
		else {
		mddev->ro = 1;
		err = do_md_run(mddev);
		}
		break;
		case read_auto:
		/* stopping an active array */
		if (mddev->pers) {
		err = do_md_stop(mddev, 1);
		if (err == 0)
		mddev->ro = 2; /* FIXME mark devices writable */
		} else {
		mddev->ro = 2;
		err = do_md_run(mddev);
		}
		break;
		case clean:
		if (mddev->pers) {
		restart_array(mddev);
		spin_lock_irq(&mddev->write_lock);
		if (atomic_read(&mddev->writes_pending) == 0) {
		mddev->in_sync = 1;
		mddev->sb_dirty = 1;
		}
		spin_unlock_irq(&mddev->write_lock);
		} else {
		mddev->ro = 0;
		mddev->recovery_cp = MaxSector;
		err = do_md_run(mddev);
		}
		break;
		case active:
		if (mddev->pers) {
		restart_array(mddev);
		mddev->sb_dirty = 0;
		wake_up(&mddev->sb_wait);
		err = 0;
		} else {
		mddev->ro = 0;
		err = do_md_run(mddev);
		}
		break;
		case write_pending:
		case active_idle:
		/* these cannot be set */
		break;
		}
		if (err)
		return err;
		else
		return len;
		}
		static struct md_sysfs_entry md_array_state = __ATTR(array_state, 0644, array_state_show, array_state_store);

		static ssize_t
		null_show(mddev_t mddev, char page)
		{
		@@ -2553,6 +2723,7 @@ static struct attribute *md_default_attrs[] = {
		&md_metadata.attr,
		&md_new_device.attr,
		&md_safe_delay.attr,
		&md_array_state.attr,
		NULL,
		};

		@@ -2919,11 +3090,8 @@ static int restart_array(mddev_t *mddev)
		md_wakeup_thread(mddev->thread);
		md_wakeup_thread(mddev->sync_thread);
		err = 0;
		} else {
		printk(KERN_ERR "md: %s has no personality assigned.\n",
		mdname(mddev));
		} else
		err = -EINVAL;
		}

		out:
		return err;
		@@ -2955,7 +3123,12 @@ static void restore_bitmap_write_access(struct file *file)
		spin_unlock(&inode->i_lock);
		}

		static int do_md_stop(mddev_t * mddev, int ro)
		/* mode:
		* 0 - completely stop and dis-assemble array
		* 1 - switch to readonly
		* 2 - stop but do not disassemble array
		*/
		static int do_md_stop(mddev_t * mddev, int mode)
		{
		int err = 0;
		struct gendisk *disk = mddev->gendisk;
		@@ -2977,12 +3150,15 @@ static int do_md_stop(mddev_t * mddev, int ro)

		invalidate_partition(disk, 0);

		if (ro) {
		switch(mode) {
		case 1: /* readonly */
		err = -ENXIO;
		if (mddev->ro==1)
		goto out;
		mddev->ro = 1;
		} else {
		break;
		case 0: /* disassemble */
		case 2: /* stop */
		bitmap_flush(mddev);
		md_super_wait(mddev);
		if (mddev->ro)
		@@ -3002,7 +3178,7 @@ static int do_md_stop(mddev_t * mddev, int ro)
		mddev->in_sync = 1;
		md_update_sb(mddev);
		}
		if (ro)
		if (mode == 1)
		set_disk_ro(disk, 1);
		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
		}
		@@ -3010,7 +3186,7 @@ static int do_md_stop(mddev_t * mddev, int ro)
		/*
		* Free resources if final stop
		*/
		if (!ro) {
		if (mode == 0) {
		mdk_rdev_t *rdev;
		struct list_head *tmp;
		struct gendisk *disk;
		@@ -3034,6 +3210,9 @@ static int do_md_stop(mddev_t * mddev, int ro)
		export_array(mddev);

		mddev->array_size = 0;
		mddev->size = 0;
		mddev->raid_disks = 0;

		disk = mddev->gendisk;
		if (disk)
		set_capacity(disk, 0);

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