When creating a new backing file, we can optionally fully claim its
storage in the fs by writing to all of it, or simply seek to the end
and write a byte, in which case the fs may allocate it as a sparse file.
Signed-off-by: Andy Grover <agrover@xxxxxxxxxx>
---
targetcli/ui_backstore.py | 43 +++++++++++++++++++++++++++++--------------
1 files changed, 29 insertions(+), 14 deletions(-)
diff --git a/targetcli/ui_backstore.py b/targetcli/ui_backstore.py
index ad25732..b8f6963 100644
--- a/targetcli/ui_backstore.py
+++ b/targetcli/ui_backstore.py
@@ -226,7 +226,26 @@ class UIFileIOBackstore(UIBackstore):
def __init__(self, parent):
UIBackstore.__init__(self, 'fileio', parent)
- def ui_command_create(self, name, file_or_dev, size=None, buffered=None):
+ def _create_file(self, filename, size, sparse=True):
+ f = open(filename, "w+")
+ try:
+ if sparse:
+ f.seek(size-1)
+ f.write("\0")
+ else:
+ self.shell.log.info("Writing %s bytes" % size)
+ while size > 0:
+ write_size = min(size, 1024)
+ f.write("\0" * write_size)
+ size -= write_size
+ except IOError:
+ f.close()
+ os.remove(filename)
+ raise ExecutionError("Could not expand file to size")
+ f.close()
+
+ def ui_command_create(self, name, file_or_dev, size=None, buffered=None,
+ sparse=None):
'''
Creates a FileIO storage object. If I{file_or_dev} is a path to a
regular file to be used as backend, then the I{size} parameter is
@@ -235,7 +254,10 @@ class UIFileIOBackstore(UIBackstore):
the file to be used, I{file} the path to the file or I{dev} the path to
a block device. The I{buffered} parameter is a boolean stating
whether or not to enable buffered mode. It is disabled by default
- (synchronous mode).
+ (synchronous mode). The I{sparse} parameter is only applicable when
+ creating a new backing file. It is a boolean stating if the
+ created file should be created as a sparse file (the default), or
+ fully initialized.
SIZE SYNTAX
===========
@@ -249,8 +271,10 @@ class UIFileIOBackstore(UIBackstore):
'''
self.assert_root()
self.assert_available_so_name(name)
- self.shell.log.debug("Using params size=%s buffered=%s"
- % (size, buffered))
+ self.shell.log.debug("Using params size=%s buffered=%s sparse=%s"
+ % (size, buffered, sparse))
+
+ sparse = self.ui_eval_param(sparse, 'bool', True)
backstore = FileIOBackstore(self.next_hba_index(), mode='create')
@@ -275,16 +299,7 @@ class UIFileIOBackstore(UIBackstore):
if not size:
raise ExecutionError("Attempting to create file for new" +
" fileio backstore, need a size")
-
- f = open(file_or_dev, "w+")
- try:
- f.seek(human_to_bytes(size)-1)
- f.write('\0')
- except IOError:
- f.close()
- os.remove(file_or_dev)
- raise ExecutionError("Could not expand file to size")
- f.close()
+ self._create_file(file_or_dev, human_to_bytes(size), sparse)
try:
so = FileIOStorageObject(
--
1.7.1
--
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