cgroup, writeback: replace SB_I_CGROUPWB with per-inode S_CGROUPWB
Currently, filesystem can indiate cgroup writeback support per
superblock; however, depending on the filesystem, especially if inodes
are used to carry metadata, it can be useful to indicate cgroup
writeback support per inode.
This patch replaces the superblock flag SB_I_CGROUPWB with per-inode
S_CGROUPWB, so that cgroup writeback can be enabled selectively.
* block_dev sets the new flag in bdget() when initializing new inode.
* ext2/4 set the new flag in ext?_set_inode_flags() function.
* btrfs sets the new flag in btrfs_update_iflags() function. Note
that this automatically excludes btree_inode which doesn't use
btrfs_update_iflags() during initialization. This is an intended
behavior change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: linux-btrfs@vger.kernel.org
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
9 files changed
