This patchset introduces the btrfs property subgroup. It is the
result of a discussion we had on IRC. I tried to make the properties
interface as generic and extensible as possible. Comments are welcome.
Currently the command group looks like this:
btrfs prop set [-t <type>] /path/to/object <name> <value>
btrfs prop get [-t <type>] /path/to/object [<name>] (omitting name dumps all)
btrfs prop list [-t <type>] /path/to/object (lists properties with description)
The type is used to explicitly specify what type of object you mean. This is
necessary in case the object+property combination is ambiguous. For example
'/path/to/fs/root' could mean the root subvolume, the directory inode or the
filesystem itself. Normally, btrfs-progs will try to detect the type
automatically.
David suggested that it should also be possible to specify objects by
their id/uuid/fsid. I like that idea, but would be happy if someone else
could take over that part :)
For now, I've implemented two properties:
1. read-only. Usable on subvolumes to toggle the read-only flags.
2. label. I looked through btrfs to find good examples of things that
could be moved to the new properties interface and the filesystem
label looked like a good one. There are for sure more, but that is
something for later (and maybe for someone else). I would suggest
to move everthing that makes sense over to the props interface and
mark the old interfaces as deprecated. Comments on this are welcome.
Patch version history:
v1
Initial version.
v2
- Removed the filesystem prefix and implemented it as new command group
- Switched from the <name>[=<value>] form to the set/get <name> [<value>]
form.
- Removed patches "Btrfs-progs: make filesystem_cmd_group non const"
and "Btrfs-progs: move skip_prefix and prefixcmp to utils.c". They
are not needed anymore due to the 'btrfs prop list' command.
- Udjusted the subvol flags patch to be compatible to the "Btrfs: use
_IOR for BTRFS_IOC_SUBVOL_GETFLAGS" patch.
- Using -t <type> instead of <type>: prefix now.
- Changes are based on feedback from Ilya and David.
Alex.
Alexander Block (3):
Btrfs-progs: add BTRFS_IOC_SUBVOL_GET/SETFLAGS to ioctl.h
Btrfs-progs: let get_label return the label instead of of printing it
Btrfs-progs: introduce btrfs property subgroup
Makefile | 5 +-
btrfs.c | 1 +
btrfslabel.c | 13 +-
btrfslabel.h | 4 +-
cmds-filesystem.c | 14 +-
cmds-property.c | 459 +++++++++++++++++++++++++++++++++++++++++++++++++++++
commands.h | 2 +
ioctl.h | 2 +
props.c | 114 +++++++++++++
props.h | 43 +++++
10 files changed, 645 insertions(+), 12 deletions(-)
create mode 100644 cmds-property.c
create mode 100644 props.c
create mode 100644 props.h
--
1.7.10
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