Fix a possible race condition if two processes try to claim the same loop

device at the same time.  We should only CLR_FD if the set status fails,
not if the SET_FD fails.
This commit is contained in:
Rob Landley 2006-06-25 15:29:12 +00:00
parent 768945b762
commit 934da82913

View File

@ -118,9 +118,10 @@ int set_loop(char **device, const char *file, int offset)
safe_strncpy((char *)loopinfo.lo_file_name, file, LO_NAME_SIZE);
loopinfo.lo_offset = offset;
/* Associate free loop device with file. */
if(!ioctl(dfd, LOOP_SET_FD, ffd) &&
!ioctl(dfd, BB_LOOP_SET_STATUS, &loopinfo)) rc=0;
if(!ioctl(dfd, LOOP_SET_FD, ffd)) {
if (!ioctl(dfd, BB_LOOP_SET_STATUS, &loopinfo)) rc=0;
else ioctl(dfd, LOOP_CLR_FD, 0);
}
/* If this block device already set up right, re-use it.
(Yes this is racy, but associating two loop devices with the same