For partitions, retrieve the logical block size of the parent device

Partitions have a sysfs "size" but no "logical_block_size".
As a consequence, we need to look at the parent device to
determine the physical block size of a partition.

This patch fixes an exception raised in `targetcli` when
partitions are listed under /backstores/block:

  FileNotFoundError: [Errno 2] No such file or directory:
  '/sys/block/sdb/sdb1/queue/logical_block_size'

Signed-off-by: Christophe Vu-Brugier <cvubrugier@yahoo.fr>

1 files changed, 4 insertions, 2 deletions

diff --git a/rtslib/utils.py b/rtslib/utils.py
index 5e5d9d2..e1b417d 100644
--- a/rtslib/utils.py
+++ b/rtslib/utils.py
@@ -116,8 +116,10 @@ def get_blockdev_size(path):
     name = os.path.basename(os.path.realpath(path))
 
     # size is in 512-byte sectors, we want to return number of logical blocks
-    def get_size(path):
+    def get_size(path, is_partition=False):
         sect_size = int(fread("%s/size" % path))
+        if is_partition:
+            path = os.path.split(path)[0]
         logical_block_size = int(fread("%s/queue/logical_block_size" % path))
         return sect_size / (logical_block_size / 512)
 
@@ -132,7 +134,7 @@ def get_blockdev_size(path):
             disk = m.groups()[0]
             if disk[-1] == 'p' and disk[-2].isdigit():
                 disk = disk[:-1]
-            return get_size("/sys/block/%s/%s" % (disk, m.group()))
+            return get_size("/sys/block/%s/%s" % (disk, m.group()), True)
         else:
             raise