Commit d67ee213 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm: add presuspend_undo hook to target_type 



The DM thin-pool target now must undo the changes performed during
pool_presuspend() so introduce presuspend_undo hook in target_type.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Acked-by: default avatarJoe Thornber <ejt@redhat.com>
parent 4d341d82

drivers/md/dm-table.c

+29 −7
Original line number Diff line number Diff line
@@ -1521,18 +1521,32 @@ fmode_t dm_table_get_mode(struct dm_table *t) 
}

EXPORT_SYMBOL(dm_table_get_mode);



static void suspend_targets(struct dm_table *t, unsigned postsuspend)

enum suspend_mode {

	PRESUSPEND,

	PRESUSPEND_UNDO,

	POSTSUSPEND,

};



static void suspend_targets(struct dm_table *t, enum suspend_mode mode)

{

	int i = t->num_targets;

	struct dm_target *ti = t->targets;



	while (i--) {

		if (postsuspend) {

		switch (mode) {

		case PRESUSPEND:

			if (ti->type->presuspend)

				ti->type->presuspend(ti);

			break;

		case PRESUSPEND_UNDO:

			if (ti->type->presuspend_undo)

				ti->type->presuspend_undo(ti);

			break;

		case POSTSUSPEND:

			if (ti->type->postsuspend)

				ti->type->postsuspend(ti);

		} else if (ti->type->presuspend)

			ti->type->presuspend(ti);



			break;

		}

		ti++;

	}

}
@@ -1542,7 +1556,15 @@ void dm_table_presuspend_targets(struct dm_table *t) 
	if (!t)

		return;



	suspend_targets(t, 0);

	suspend_targets(t, PRESUSPEND);

}



void dm_table_presuspend_undo_targets(struct dm_table *t)

{

	if (!t)

		return;



	suspend_targets(t, PRESUSPEND_UNDO);

}



void dm_table_postsuspend_targets(struct dm_table *t)
@@ -1550,7 +1572,7 @@ void dm_table_postsuspend_targets(struct dm_table *t) 
	if (!t)

		return;



	suspend_targets(t, 1);

	suspend_targets(t, POSTSUSPEND);

}



int dm_table_resume_targets(struct dm_table *t)

drivers/md/dm.c

+8 −2
Original line number Diff line number Diff line
@@ -2756,7 +2756,10 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) 
	if (noflush)

		set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);



	/* This does not get reverted if there's an error later. */

	/*

	 * This gets reverted if there's an error later and the targets

	 * provide the .presuspend_undo hook.

	 */

	dm_table_presuspend_targets(map);



	/*
@@ -2767,9 +2770,11 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) 
	 */

	if (!noflush && do_lockfs) {

		r = lock_fs(md);

		if (r)

		if (r) {

			dm_table_presuspend_undo_targets(map);

			goto out_unlock;

		}

	}



	/*

	 * Here we must make sure that no processes are submitting requests
@@ -2816,6 +2821,7 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) 
			start_queue(md->queue);



		unlock_fs(md);

		dm_table_presuspend_undo_targets(map);

		goto out_unlock; /* pushback list is already flushed, so skip flush */

	}

drivers/md/dm.h

+1 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, 
			       struct queue_limits *limits);

struct list_head *dm_table_get_devices(struct dm_table *t);

void dm_table_presuspend_targets(struct dm_table *t);

void dm_table_presuspend_undo_targets(struct dm_table *t);

void dm_table_postsuspend_targets(struct dm_table *t);

int dm_table_resume_targets(struct dm_table *t);

int dm_table_any_congested(struct dm_table *t, int bdi_bits);

include/linux/device-mapper.h

+2 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ typedef int (*dm_request_endio_fn) (struct dm_target *ti, 
				    union map_info *map_context);



typedef void (*dm_presuspend_fn) (struct dm_target *ti);

typedef void (*dm_presuspend_undo_fn) (struct dm_target *ti);

typedef void (*dm_postsuspend_fn) (struct dm_target *ti);

typedef int (*dm_preresume_fn) (struct dm_target *ti);

typedef void (*dm_resume_fn) (struct dm_target *ti);
@@ -145,6 +146,7 @@ struct target_type { 
	dm_endio_fn end_io;

	dm_request_endio_fn rq_end_io;

	dm_presuspend_fn presuspend;

	dm_presuspend_undo_fn presuspend_undo;

	dm_postsuspend_fn postsuspend;

	dm_preresume_fn preresume;

	dm_resume_fn resume;

include/uapi/linux/dm-ioctl.h

+2 −2
Original line number Diff line number Diff line
@@ -267,9 +267,9 @@ enum { 
#define DM_DEV_SET_GEOMETRY	_IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)



#define DM_VERSION_MAJOR	4

#define DM_VERSION_MINOR	28

#define DM_VERSION_MINOR	29

#define DM_VERSION_PATCHLEVEL	0

#define DM_VERSION_EXTRA	"-ioctl (2014-09-17)"

#define DM_VERSION_EXTRA	"-ioctl (2014-10-28)"



/* Status bits */

#define DM_READONLY_FLAG	(1 << 0) /* In/Out */