dm thin: detect metadata device resizing
Allow the dm thin pool metadata device to be extended.
Whenever a pool is resumed, detect whether the size of the metadata
device has increased, and if so, extend the metadata to use the new
space.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index ef021b0..f4632f9 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -1923,6 +1923,15 @@
return metadata_dev_size;
}
+static dm_block_t get_metadata_dev_size_in_blocks(struct block_device *bdev)
+{
+ sector_t metadata_dev_size = get_metadata_dev_size(bdev);
+
+ sector_div(metadata_dev_size, THIN_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
+
+ return metadata_dev_size;
+}
+
/*
* thin-pool <metadata dev> <data dev>
* <data block size (sectors)>
@@ -2132,6 +2141,41 @@
return 0;
}
+static int maybe_resize_metadata_dev(struct dm_target *ti, bool *need_commit)
+{
+ int r;
+ struct pool_c *pt = ti->private;
+ struct pool *pool = pt->pool;
+ dm_block_t metadata_dev_size, sb_metadata_dev_size;
+
+ *need_commit = false;
+
+ metadata_dev_size = get_metadata_dev_size(pool->md_dev);
+
+ r = dm_pool_get_metadata_dev_size(pool->pmd, &sb_metadata_dev_size);
+ if (r) {
+ DMERR("failed to retrieve data device size");
+ return r;
+ }
+
+ if (metadata_dev_size < sb_metadata_dev_size) {
+ DMERR("metadata device (%llu sectors) too small: expected %llu",
+ metadata_dev_size, sb_metadata_dev_size);
+ return -EINVAL;
+
+ } else if (metadata_dev_size > sb_metadata_dev_size) {
+ r = dm_pool_resize_metadata_dev(pool->pmd, metadata_dev_size);
+ if (r) {
+ DMERR("failed to resize metadata device");
+ 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,
@@ -2146,7 +2190,7 @@
static int pool_preresume(struct dm_target *ti)
{
int r;
- bool need_commit1;
+ bool need_commit1, need_commit2;
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
@@ -2161,7 +2205,11 @@
if (r)
return r;
- if (need_commit1)
+ r = maybe_resize_metadata_dev(ti, &need_commit2);
+ if (r)
+ return r;
+
+ if (need_commit1 || need_commit2)
(void) commit_or_fallback(pool);
return 0;
@@ -2583,7 +2631,7 @@
.name = "thin-pool",
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
DM_TARGET_IMMUTABLE,
- .version = {1, 7, 0},
+ .version = {1, 8, 0},
.module = THIS_MODULE,
.ctr = pool_ctr,
.dtr = pool_dtr,