loopfs: start attaching correct namespace during loop_add()
Tag loop devices with the namespace the loopfs instance was mounted in.
This has the consequence that loopfs devices carry the correct sysfs
permissions for all their core files. All other devices files will
continue to be correctly owned by the initial namespaces. Here is sample
output:
root@b1:~# mount -t loop loop /mnt
root@b1:~# ln -sf /mnt/loop-control /dev/loop-control
root@b1:~# losetup -f
/dev/loop8
root@b1:~# ln -sf /mnt/loop8 /dev/loop8
root@b1:~# ls -al /sys/class/block/loop8
lrwxrwxrwx 1 root root 0 Apr 7 13:06 /sys/class/block/loop8 -> ../../devices/virtual/block/loop8
root@b1:~# ls -al /sys/class/block/loop8/
total 0
drwxr-xr-x 9 root root 0 Apr 7 13:06 .
drwxr-xr-x 18 nobody nogroup 0 Apr 7 13:07 ..
-r--r--r-- 1 root root 4096 Apr 7 13:06 alignment_offset
lrwxrwxrwx 1 nobody nogroup 0 Apr 7 13:07 bdi -> ../../bdi/7:8
-r--r--r-- 1 root root 4096 Apr 7 13:06 capability
-r--r--r-- 1 root root 4096 Apr 7 13:06 dev
-r--r--r-- 1 root root 4096 Apr 7 13:06 discard_alignment
-r--r--r-- 1 root root 4096 Apr 7 13:06 events
-r--r--r-- 1 root root 4096 Apr 7 13:06 events_async
-rw-r--r-- 1 root root 4096 Apr 7 13:06 events_poll_msecs
-r--r--r-- 1 root root 4096 Apr 7 13:06 ext_range
-r--r--r-- 1 root root 4096 Apr 7 13:06 hidden
drwxr-xr-x 2 nobody nogroup 0 Apr 7 13:07 holders
-r--r--r-- 1 root root 4096 Apr 7 13:06 inflight
drwxr-xr-x 2 nobody nogroup 0 Apr 7 13:07 integrity
drwxr-xr-x 3 nobody nogroup 0 Apr 7 13:07 mq
drwxr-xr-x 2 root root 0 Apr 7 13:06 power
drwxr-xr-x 3 nobody nogroup 0 Apr 7 13:07 queue
-r--r--r-- 1 root root 4096 Apr 7 13:06 range
-r--r--r-- 1 root root 4096 Apr 7 13:06 removable
-r--r--r-- 1 root root 4096 Apr 7 13:06 ro
-r--r--r-- 1 root root 4096 Apr 7 13:06 size
drwxr-xr-x 2 nobody nogroup 0 Apr 7 13:07 slaves
-r--r--r-- 1 root root 4096 Apr 7 13:06 stat
lrwxrwxrwx 1 nobody nogroup 0 Apr 7 13:07 subsystem -> ../../../../class/block
drwxr-xr-x 2 root root 0 Apr 7 13:06 trace
-rw-r--r-- 1 root root 4096 Apr 7 13:06 uevent
root@b1:~#
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
/* v2 */
unchanged
- Christian Brauner <christian.brauner@ubuntu.com>:
- Adapted commit message otherwise unchanged.
1 file changed
