Commit b17446df authored by Joe Thornber's avatar Joe Thornber Committed by Alasdair G Kergon
Browse files

dm thin: refactor data dev resize 



Refactor device size functions in preparation for similar metadata
device resizing functions.

Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 8c5008fa

drivers/md/dm-thin-metadata.c

+5 −5
Original line number Diff line number Diff line
@@ -1645,12 +1645,12 @@ int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, 
	return r;

}



static int __resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)

static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)

{

	int r;

	dm_block_t old_count;



	r = dm_sm_get_nr_blocks(pmd->data_sm, &old_count);

	r = dm_sm_get_nr_blocks(sm, &old_count);

	if (r)

		return r;
@@ -1658,11 +1658,11 @@ static int __resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 
		return 0;



	if (new_count < old_count) {

		DMERR("cannot reduce size of data device");

		DMERR("cannot reduce size of space map");

		return -EINVAL;

	}



	return dm_sm_extend(pmd->data_sm, new_count - old_count);

	return dm_sm_extend(sm, new_count - old_count);

}



int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
@@ -1671,7 +1671,7 @@ int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 


	down_write(&pmd->root_lock);

	if (!pmd->fail_io)

		r = __resize_data_dev(pmd, new_count);

		r = __resize_space_map(pmd->data_sm, new_count);

	up_write(&pmd->root_lock);



	return r;

drivers/md/dm-thin.c

+59 −28
Original line number Diff line number Diff line
@@ -922,7 +922,7 @@ static int alloc_data_block(struct thin_c *tc, dm_block_t *result) 
		return r;



	if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) {

		DMWARN("%s: reached low water mark, sending event.",

		DMWARN("%s: reached low water mark for data device: sending event.",

		       dm_device_name(pool->pool_md));

		spin_lock_irqsave(&pool->lock, flags);

		pool->low_water_triggered = 1;
@@ -1909,6 +1909,20 @@ static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf, 
	return r;

}



static sector_t get_metadata_dev_size(struct block_device *bdev)

{

	sector_t metadata_dev_size = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;

	char buffer[BDEVNAME_SIZE];



	if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING) {

		DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",

		       bdevname(bdev, buffer), THIN_METADATA_MAX_SECTORS);

		metadata_dev_size = THIN_METADATA_MAX_SECTORS_WARNING;

	}



	return metadata_dev_size;

}



/*

 * thin-pool <metadata dev> <data dev>

 *	     <data block size (sectors)>
@@ -1931,8 +1945,6 @@ static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) 
	unsigned long block_size;

	dm_block_t low_water_blocks;

	struct dm_dev *metadata_dev;

	sector_t metadata_dev_size;

	char b[BDEVNAME_SIZE];



	/*

	 * FIXME Remove validation from scope of lock.
@@ -1953,10 +1965,11 @@ static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) 
		goto out_unlock;

	}



	metadata_dev_size = i_size_read(metadata_dev->bdev->bd_inode) >> SECTOR_SHIFT;

	if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING)

		DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",

		       bdevname(metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS);

	/*

	 * Run for the side-effect of possibly issuing a warning if the

	 * device is too big.

	 */

	(void) get_metadata_dev_size(metadata_dev->bdev);



	r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev);

	if (r) {
@@ -2079,18 +2092,7 @@ static int pool_map(struct dm_target *ti, struct bio *bio) 
	return r;

}



/*

 * Retrieves the number of blocks of the data device from

 * the superblock and compares it to the actual device size,

 * thus resizing the data device in case it has grown.

 *

 * This both copes with opening preallocated data devices in the ctr

 * being followed by a resume

 * -and-

 * calling the resume method individually after userspace has

 * grown the data device in reaction to a table event.

 */

static int pool_preresume(struct dm_target *ti)

static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit)

{

	int r;

	struct pool_c *pt = ti->private;
@@ -2098,12 +2100,7 @@ static int pool_preresume(struct dm_target *ti) 
	sector_t data_size = ti->len;

	dm_block_t sb_data_size;



	/*

	 * Take control of the pool object.

	 */

	r = bind_control_target(pool, ti);

	if (r)

		return r;

	*need_commit = false;



	(void) sector_div(data_size, pool->sectors_per_block);
@@ -2114,7 +2111,7 @@ static int pool_preresume(struct dm_target *ti) 
	}



	if (data_size < sb_data_size) {

		DMERR("pool target too small, is %llu blocks (expected %llu)",

		DMERR("pool target (%llu blocks) too small: expected %llu",

		      (unsigned long long)data_size, sb_data_size);

		return -EINVAL;
@@ -2122,17 +2119,51 @@ static int pool_preresume(struct dm_target *ti) 
		r = dm_pool_resize_data_dev(pool->pmd, data_size);

		if (r) {

			DMERR("failed to resize data device");

			/* FIXME Stricter than necessary: Rollback transaction instead here */

			set_pool_mode(pool, PM_READ_ONLY);

			return r;

		}



		(void) commit_or_fallback(pool);

		*need_commit = true;

	}



	return 0;

}



/*

 * Retrieves the number of blocks of the data device from

 * the superblock and compares it to the actual device size,

 * thus resizing the data device in case it has grown.

 *

 * This both copes with opening preallocated data devices in the ctr

 * being followed by a resume

 * -and-

 * calling the resume method individually after userspace has

 * grown the data device in reaction to a table event.

 */

static int pool_preresume(struct dm_target *ti)

{

	int r;

	bool need_commit1;

	struct pool_c *pt = ti->private;

	struct pool *pool = pt->pool;



	/*

	 * Take control of the pool object.

	 */

	r = bind_control_target(pool, ti);

	if (r)

		return r;



	r = maybe_resize_data_dev(ti, &need_commit1);

	if (r)

		return r;



	if (need_commit1)

		(void) commit_or_fallback(pool);



	return 0;

}



static void pool_resume(struct dm_target *ti)

{

	struct pool_c *pt = ti->private;