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authorEd Bartosh <ed.bartosh@linux.intel.com>2016-04-28 13:58:04 +0300
committerRichard Purdie <richard.purdie@linuxfoundation.org>2016-05-06 10:31:12 +0100
commitd03cbac7960c8f39019f2f428647e8100ddc5da0 (patch)
tree7015264912dc51b07ca6819dd25f0d48c547d97e /scripts/lib/wic/partition.py
parente93254b482c09aba884160ea6fea3756702cb1e8 (diff)
downloadopenembedded-core-contrib-d03cbac7960c8f39019f2f428647e8100ddc5da0.tar.gz
wic: use truncate utility to create sparse files
Used truncate instead of dd to create wic images for the following reasons: - dd doesn't preserve sparseness - truncate syntax is much more clear - dd requires additional calculations of the image size in blocks - the way dd was used in the code is not always correct. In some cases it was writing one block to the file which makes it not 100% sparse. [YOCTO #9099] (From OE-Core rev: d2d0d18dfd3922411d856b98ab6ba5d64c9c1c9f) Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'scripts/lib/wic/partition.py')
-rw-r--r--scripts/lib/wic/partition.py20
1 files changed, 5 insertions, 15 deletions
diff --git a/scripts/lib/wic/partition.py b/scripts/lib/wic/partition.py
index 227b685137..6d21193902 100644
--- a/scripts/lib/wic/partition.py
+++ b/scripts/lib/wic/partition.py
@@ -220,9 +220,7 @@ class Partition(object):
msger.debug("Added %d extra blocks to %s to get to %d total blocks" % \
(extra_blocks, self.mountpoint, rootfs_size))
- dd_cmd = "dd if=/dev/zero of=%s bs=1024 seek=%d count=0 bs=1k" % \
- (rootfs, rootfs_size)
- exec_cmd(dd_cmd)
+ exec_cmd("truncate %s -s %d" % (rootfs, rootfs_size * 1024))
extra_imagecmd = "-i 8192"
@@ -255,9 +253,7 @@ class Partition(object):
msger.debug("Added %d extra blocks to %s to get to %d total blocks" % \
(extra_blocks, self.mountpoint, rootfs_size))
- dd_cmd = "dd if=/dev/zero of=%s bs=1024 seek=%d count=0 bs=1k" % \
- (rootfs, rootfs_size)
- exec_cmd(dd_cmd)
+ exec_cmd("truncate %s -s %d" % (rootfs, rootfs_size * 1024))
label_str = ""
if self.label:
@@ -320,9 +316,7 @@ class Partition(object):
"""
Prepare an empty ext2/3/4 partition.
"""
- dd_cmd = "dd if=/dev/zero of=%s bs=1k seek=%d count=0" % \
- (rootfs, self.size)
- exec_cmd(dd_cmd)
+ exec_cmd("truncate %s -s %d" % (rootfs, self.size * 1024))
extra_imagecmd = "-i 8192"
@@ -339,9 +333,7 @@ class Partition(object):
"""
Prepare an empty btrfs partition.
"""
- dd_cmd = "dd if=/dev/zero of=%s bs=1k seek=%d count=0" % \
- (rootfs, self.size)
- exec_cmd(dd_cmd)
+ exec_cmd("truncate %s -s %d" % (rootfs, self.size * 1024))
label_str = ""
if self.label:
@@ -402,9 +394,7 @@ class Partition(object):
"""
path = "%s/fs.%s" % (cr_workdir, self.fstype)
- dd_cmd = "dd if=/dev/zero of=%s bs=1k seek=%d count=0" % \
- (path, self.size)
- exec_cmd(dd_cmd)
+ exec_cmd("truncate %s -s %d" % (path, self.size * 1024))
import uuid
label_str = ""