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confluent/confluent_client/bin/dir2img
Jarrod Johnson 231582dd0f Workaround mtools on cluster fs
When a lock is acquired by mtools,
it does not ensure it releases the
lock before exit.

Workaround this by doing a blocking
lock and unlock after any
invocation of mtools.
2020-06-16 16:36:02 -04:00

53 lines
1.9 KiB
Python

#!/usr/bin/python
# This will take a given directory and make a 'big floppy image'
# out of it, suitable for nodemedia upload.
import fcntl
import glob
import os
import subprocess
import sys
def create_image(directory, image):
ents = 0
datasz = 512
for dir in os.walk(sys.argv[1]):
ents += 1
for filen in dir[2]:
ents += 1
filename = os.path.join(dir[0], filen)
currsz = os.path.getsize(filename)
# assuming up to 65k cluster
currsz = (currsz // 512 +1) * 512
datasz += currsz
datasz += ents * 32768
datasz = datasz // 512 + 1
with open(image, 'wb') as imgfile:
imgfile.seek(datasz * 512 - 1)
imgfile.write(b'\x00')
subprocess.check_call(['mformat', '-i', image, '-r', '16', '-d', '1', '-t',
str(datasz), '-s', '1','-h', '1', '::'])
# Some clustered filesystems will have the lock from mformat
# linger after close (mformat doesn't unlock)
# do a blocking wait for shared lock and then explicitly
# unlock between calls to mtools
with open(image, 'rb') as imgfile:
fcntl.flock(imgfile.fileno(), fcntl.LOCK_SH)
fcntl.flock(imgfile.fileno(), fcntl.LOCK_UN)
cpycmd = ['mcopy', '-i', image, '-s']
cpycmd.extend(glob.glob('{0}/*'.format(directory)))
cpycmd.append('::')
subprocess.check_call(cpycmd)
# though not necessary for us, make sure dir2img doesn't have a lingering
# flock from mcopy for any subsequent commands
with open(image, 'rb') as imgfile:
fcntl.flock(imgfile.fileno(), fcntl.LOCK_SH)
fcntl.flock(imgfile.fileno(), fcntl.LOCK_UN)
if __name__ == '__main__':
if len(sys.argv) < 3:
sys.stderr.write("Usage: {0} <directory> <imagefile>".format(
sys.argv[0]))
sys.exit(1)
create_image(sys.argv[1], sys.argv[2])