Fix strict gcc warnings that come from using:
("-Wall -Wp,-D_FORTIFY_SOURCE=2")
lomount.c:98: warning: pointer targets in initialization differ in signedness
lomount.c:111: warning: format '%04x' expects type 'unsigned int', but argument 4 has type '__kernel_old_dev_t'
lomount.c:300: warning: pointer targets in passing argument 1 of 'xstrncpy' differ in signedness
lomount.c:307: warning: pointer targets in passing argument 1 of '__builtin___snprintf_chk' differ in signedness
lomount.c:339: warning: pointer targets in passing argument 1 of 'xstrncpy' differ in signedness
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Testcase:
$ mount -oloop /etc/group /mnt
ioctl: LOOP_CLR_FD: Device or resource busy
mount: you must specify the filesystem type
$ losetup /dev/loop0
/dev/loop0: [0803]:1931929 (/etc/group)
Signed-off-by: Matthias Koenig <mkoenig@suse.de>
loop back mounting emits two system calls: mount and mlockall.
mount is obviously needed. mlockall is needed for encryption.
As the result both CAP_SYS_ADMIN and CAP_IPC_LOCK are needed
to do loopback mounting.
The problem is that CAP_IPC_LOCK is always needed through my
command doesn't need encryption.
With the following patch, mount calls mlockall only when
encryption is needed.
Signed-off-by: Masatake YAMATO <jet@gyve.org>
Fix race in losetup
Retry acquiring a loop device if set_loop failed with EBUSY
Signed-Off-By: Matthias Koenig <mkoenig@suse.de>
Signed-off-by: Karel Zak <kzak@redhat.com>
Fix race in mount -o loop
Retry acquiring a loop device if the setup failed with EBUSY.
Signed-Off-By: Matthias Koenig <mkoenig@suse.de>
Signed-off-by: Karel Zak <kzak@redhat.com>
The losetup provides an -f option to discover an unused loop device. As
implemented, it is racy. The problem is that -f prints the loop device
to stdout only when used standalone. This means a script has to do:
lodev=$(losetup -f)
losetup $lodev $filename
which is racy if another script may be running.
This patch add a new option '-s'. The '-s' option prints device name
if the -f option and a file argument are present. For example:
lodev=$(losetup -f -s $filename)
Signed-off-by: Karel Zak <kzak@redhat.com>
This feature has been already supported by mount, but it wasn't accessible by
losetup command. Now you can use "losetup -r".
Signed-off-by: Karel Zak <kzak@redhat.com>
Randy Dunlap
Sascha Sommer
Masatake YAMATO
Karel Zak
Matthias Koenig