lp:~cbrauner/ubuntu/+source/linux/+git/disco

Author: Christian Brauner
Author Date: 2019-05-07 13:24:44 UTC

UBUNTU: SAUCE: shiftfs: allow changing ro/rw for subvolumes

BugLink: https://bugs.launchpad.net/bugs/1832316

This enables toggling between ro/rw for btrfs subvolumes under shiftfs.

Currently, btrfs workloads employing shiftfs cause regression.
With btrfs unprivileged users can already toggle whether a subvolume
will be ro or rw. This is broken on current shiftfs as we haven't
whitelisted these ioctls().
To prevent such regression, we need to whitelist the ioctls
BTRFS_IOC_FS_INFO, BTRFS_IOC_SUBVOL_GETFLAGS, and
BTRFS_IOC_SUBVOL_SETFLAGS. All of them should be safe for unprivileged
users.

Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Author: Christian Brauner
Author Date: 2019-05-07 15:47:52 UTC

UBUNTU: SAUCE: shiftfs: support copy_file_range on btrfs through ioctl()

Unprivileged user can use FICLONE so we need to support it in btrfs as
well to prevent workload regression.
FICLONE first appeared in Linux 4.5. It was previously known as
BTRFS_IOC_CLONE, and were private to Btrfs.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>