mirror/borg
1
0
Fork 0
mirror of https://github.com/borgbackup/borg.git synced 2025-02-23 06:31:58 +00:00
Code Issues Releases Wiki Activity

Merge pull request #5329 from ThomasWaldmann/fix-recover-segment-master

Browse source 
check --repair: fix potential data loss (master)
This commit is contained in:
TW 2020-09-08 21:28:02 +02:00 committed by GitHub
commit f928747ff7
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 15 additions and 17 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

32
src/borg/repository.py
View file

@ -1486,23 +1486,21 @@ def recover_segment(self, segment, filename):
logger.info('attempting to recover ' + filename)
if segment in self.fds:
del self.fds[segment]
backup_filename = filename + '.beforerecover'
os.rename(filename, backup_filename)
if os.path.getsize(backup_filename) < MAGIC_LEN + self.header_fmt.size:
if os.path.getsize(filename) < MAGIC_LEN + self.header_fmt.size:
# this is either a zero-byte file (which would crash mmap() below) or otherwise
# just too small to be a valid non-empty segment file, so do a shortcut here:
with open(filename, 'wb') as fd:
with SaveFile(filename, binary=True) as fd:
fd.write(MAGIC)
return
with open(backup_filename, 'rb') as backup_fd:
# note: file must not be 0 size or mmap() will crash.
with mmap.mmap(backup_fd.fileno(), 0, access=mmap.ACCESS_READ) as mm:
# memoryview context manager is problematic, see https://bugs.python.org/issue35686
data = memoryview(mm)
d = data
try:
with open(filename, 'wb') as fd:
fd.write(MAGIC)
with SaveFile(filename, binary=True) as dst_fd:
with open(filename, 'rb') as src_fd:
# note: file must not be 0 size or mmap() will crash.
with mmap.mmap(src_fd.fileno(), 0, access=mmap.ACCESS_READ) as mm:
# memoryview context manager is problematic, see https://bugs.python.org/issue35686
data = memoryview(mm)
d = data
try:
dst_fd.write(MAGIC)
while len(d) >= self.header_fmt.size:
crc, size, tag = self.header_fmt.unpack(d[:self.header_fmt.size])
if size < self.header_fmt.size or size > len(d):
@ -1511,11 +1509,11 @@ def recover_segment(self, segment, filename):
if crc32(d[4:size]) & 0xffffffff != crc:
d = d[1:]
continue
fd.write(d[:size])
dst_fd.write(d[:size])
d = d[size:]
finally:
del d
data.release()
finally:
del d
data.release()
def read(self, segment, offset, id, read_data=True):
"""