On Wed, Dec 9, 2020 at 10:19 AM Thomas De Schampheleire <[email protected]> wrote: > From: Philippe Belet <[email protected]> > > When mounting, in parallel, multiple loop devices (squashfs for the > submitter's case), the following behavior can be observed: > > stat64(/path/to/image, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0 > openat(AT_FDCWD, /path/to/image, O_RDWR|O_LARGEFILE) = 3 > openat(AT_FDCWD, /dev/loop-control, O_RDWR|O_LARGEFILE|O_CLOEXEC) = 4 > ioctl(4, LOOP_CTL_GET_FREE) = 12 > close(4) = 0 > openat(AT_FDCWD, /dev/loop12, O_RDWR|O_LARGEFILE) = 4 > ioctl(4, LOOP_GET_STATUS64, {lo_offset=0, lo_number=12, > lo_flags=LO_FLAGS_AUTOCLEAR, lo_file_name=/path/to/image, ...}) = 0 > close(4) = 0 > close(3) = 0 > write(2, "mount: can't setup loop device\n", 31mount: can't setup loop device > ) = 31 > exit_group(0) = ? > +++ exited with 0 +++ > > The ioctl LOOP_CTL_GET_FREE has resulted in the same result for > a competing mount process. The subsequent ioctl LOOP_GET_STATUS64 > fails, having succeeded for the competing mount process. Next we > see a series of other system calls. > > The mount code checks the errno value of the last close() > syscall
No it does not. errno is not cleared to zero on successful syscalls, it's left untouched. Does just this change: - return errno; + return loopfd; fix the problem? _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
