dm thin: refactor data dev resize

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

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Joe Thornber 2013-05-10 14:37:18 +01:00 committed by Alasdair G Kergon
parent 8c5008fac4
commit b17446df2e
2 changed files with 66 additions and 35 deletions

View File

@ -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;

View File

@ -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) {
@ -2079,6 +2092,43 @@ static int pool_map(struct dm_target *ti, struct bio *bio)
return r;
}
static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit)
{
int r;
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
sector_t data_size = ti->len;
dm_block_t sb_data_size;
*need_commit = false;
(void) sector_div(data_size, pool->sectors_per_block);
r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
if (r) {
DMERR("failed to retrieve data device size");
return r;
}
if (data_size < sb_data_size) {
DMERR("pool target (%llu blocks) too small: expected %llu",
(unsigned long long)data_size, sb_data_size);
return -EINVAL;
} else if (data_size > sb_data_size) {
r = dm_pool_resize_data_dev(pool->pmd, data_size);
if (r) {
DMERR("failed to resize data device");
set_pool_mode(pool, PM_READ_ONLY);
return r;
}
*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,
@ -2093,10 +2143,9 @@ static int pool_map(struct dm_target *ti, struct bio *bio)
static int pool_preresume(struct dm_target *ti)
{
int r;
bool need_commit1;
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
sector_t data_size = ti->len;
dm_block_t sb_data_size;
/*
* Take control of the pool object.
@ -2105,30 +2154,12 @@ static int pool_preresume(struct dm_target *ti)
if (r)
return r;
(void) sector_div(data_size, pool->sectors_per_block);
r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
if (r) {
DMERR("failed to retrieve data device size");
r = maybe_resize_data_dev(ti, &need_commit1);
if (r)
return r;
}
if (data_size < sb_data_size) {
DMERR("pool target too small, is %llu blocks (expected %llu)",
(unsigned long long)data_size, sb_data_size);
return -EINVAL;
} else if (data_size > sb_data_size) {
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;
}
if (need_commit1)
(void) commit_or_fallback(pool);
}
return 0;
}