Messages in this thread | | | Date | Sun, 14 Jun 2015 00:42:36 -0500 | From | Tejun Heo <> | Subject | Re: [PATCH 2/3] vfs, writeback: replace FS_CGROUP_WRITEBACK with MS_CGROUPWB |
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Hello, Christoph.
On Sat, Jun 13, 2015 at 09:16:08AM -0700, Christoph Hellwig wrote: > On Fri, Jun 12, 2015 at 04:57:33PM -0500, Tejun Heo wrote: > > FS_CGROUP_WRITEBACK indicates whether a file_system_type supports > > cgroup writeback; however, different super_blocks of the same > > file_system_type may or may not support cgroup writeback depending on > > filesystem options. This patch replaces FS_CGROUP_WRITEBACK with a > > kernel-internal super_block->s_flags MS_CGROUPWB. The concatenated > > and abbreviated name is for consistency with other MS_* flags. > > Nak. As the uapi part makes it obvious the MS_ namespace is part > of the userspace ABI. Please add a new in-kernel flags field instead.
Are MS_ACTIVE and MS_BORN part of userpace ABI? They seem pretty internal. I don't mind introducing a new internal flag field but it's weird to put this single flag there with other internal flags in ->s_flags.
Assuming we add a new field, how do sb->s_iflags and SB_I_XXX sound? Any better suggestions?
Thanks.
-- tejun
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