dm thin metadata: add format option to dm_pool_metadata_open

Add a parameter to dm_pool_metadata_open to indicate whether or not an
unformatted metadata area should be formatted.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

3 files changed, 12 insertions, 10 deletions

diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 1b6d2857b3f1..5ae31185e47c 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -624,7 +624,7 @@ bad_unlock_sblock:
         return r;
 }
 
-static int __open_or_format_metadata(struct dm_pool_metadata *pmd)
+static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
 {
         int r, unformatted;
 
@@ -633,12 +633,12 @@ static int __open_or_format_metadata(struct dm_pool_metadata *pmd)
                 return r;
 
         if (unformatted)
-                return __format_metadata(pmd);
-        else
-                return __open_metadata(pmd);
+                return format_device ? __format_metadata(pmd) : -EPERM;
+
+        return __open_metadata(pmd);
 }
 
-static int __create_persistent_data_objects(struct dm_pool_metadata *pmd)
+static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
 {
         int r;
 
@@ -650,7 +650,7 @@ static int __create_persistent_data_objects(struct dm_pool_metadata *pmd)
                 return PTR_ERR(pmd->bm);
         }
 
-        r = __open_or_format_metadata(pmd);
+        r = __open_or_format_metadata(pmd, format_device);
         if (r)
                 dm_block_manager_destroy(pmd->bm);
 
@@ -792,7 +792,8 @@ out_locked:
 }
 
 struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
-                                               sector_t data_block_size)
+                                               sector_t data_block_size,
+                                               bool format_device)
 {
         int r;
         struct dm_pool_metadata *pmd;
@@ -809,7 +810,7 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
         pmd->bdev = bdev;
         pmd->data_block_size = data_block_size;
 
-        r = __create_persistent_data_objects(pmd);
+        r = __create_persistent_data_objects(pmd, format_device);
         if (r) {
                 kfree(pmd);
                 return ERR_PTR(r);
diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h
index 7b47c0a9a8e3..7e6656c49bd5 100644
--- a/drivers/md/dm-thin-metadata.h
+++ b/drivers/md/dm-thin-metadata.h
@@ -38,7 +38,8 @@ typedef uint64_t dm_thin_id;
  * Reopens or creates a new, empty metadata volume.
  */
 struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
-                                               sector_t data_block_size);
+                                               sector_t data_block_size,
+                                               bool format_device);
 
 int dm_pool_metadata_close(struct dm_pool_metadata *pmd);
 
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 026215566abd..bc9d08c0218b 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -1712,7 +1712,7 @@ static struct pool *pool_create(struct mapped_device *pool_md,
         struct pool *pool;
         struct dm_pool_metadata *pmd;
 
-        pmd = dm_pool_metadata_open(metadata_dev, block_size);
+        pmd = dm_pool_metadata_open(metadata_dev, block_size, true);
         if (IS_ERR(pmd)) {
                 *error = "Error creating metadata object";
                 return (struct pool *)pmd;