Find the disk a file is located
Go through mapper, loop to find which physical device we
are using
BUG=None
TEST=Tested with the following files:
'/dev/mmcblk0p1', '/var/log/messages', '/tmp/uptime-boot-complete',
'/etc/init/cryptohomed.conf' and '/home/chronos/user/.bashrc'
Tested on secure and unsecure boot device, eMMC and SATA.
Change-Id: I593fa3afd9636135e17cea81bcc1c003cb22e37a
Reviewed-on: https://chromium-review.googlesource.com/203635
Reviewed-by: Puthikorn Voravootivat <[email protected]>
Commit-Queue: Gwendal Grignou <[email protected]>
Tested-by: Gwendal Grignou <[email protected]>
diff --git a/client/bin/base_utils.py b/client/bin/base_utils.py
index 5147a97..b52aa5c 100644
--- a/client/bin/base_utils.py
+++ b/client/bin/base_utils.py
@@ -683,7 +683,7 @@
device = os.path.basename(disk_name)
for line in file('/proc/partitions'):
try:
- major, minor, blocks, name = re.split(r' +', line.strip())
+ _, _, blocks, name = re.split(r' +', line.strip())
except ValueError:
continue
if name == device:
@@ -713,6 +713,45 @@
return utils.system_output(cmd)
+def get_disk_from_filename(filename):
+ """
+ Return the disk device the filename is on.
+ If the file is on tmpfs or other special file systems,
+ return None.
+
+ @param filename: name of file, full path.
+ """
+ re_disk = re.compile('/dev/sd[a-z]|/dev/mmcblk[0-9]*')
+
+ if not os.path.isfile(filename):
+ raise error.TestError('file %s missing' % filename)
+
+ if filename[0] != '/':
+ raise error.TestError('This code works only with full path')
+
+ m = re_disk.match(filename)
+ while not m:
+ if filename[0] != '/':
+ return None
+ if filename == '/dev/root':
+ cmd = 'rootdev -d -s'
+ elif filename.startswith('/dev/mapper'):
+ cmd = 'dmsetup table "%s"' % os.path.basename(filename)
+ dmsetup_output = utils.system_output(cmd).split(' ')
+ if dmsetup_output[2] == 'verity':
+ maj_min = dmsetup_output[4]
+ elif dmsetup_output[2] == 'crypt':
+ maj_min = dmsetup_output[6]
+ cmd = 'realpath "/dev/block/%s"' % maj_min
+ elif filename.startswith('/dev/loop'):
+ cmd = 'losetup -O BACK-FILE "%s" | tail -1' % filename
+ else:
+ cmd = 'df "%s" | tail -1 | cut -f 1 -d" "' % filename
+ filename = utils.system_output(cmd)
+ m = re_disk.match(filename)
+ return m.group(0)
+
+
def load_module(module_name):
# Checks if a module has already been loaded
if module_is_loaded(module_name):
