Commit Graph

11 Commits

Author SHA1 Message Date
Omar Sandoval 172c0d1a12 libbtrfsutil: add btrfs_util_[gs]et_read_only()
In the future, btrfs_util_[gs]et_subvolume_flags() might be useful, but
since these are the only subvolume flags we've defined in all this time,
this will do for now.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-06 11:28:36 +01:00
Omar Sandoval 0d36261bd5 libbtrfsutil: add btrfs_util_subvolume_info()
This gets the the information in `btrfs subvolume show` from the root
item.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-06 11:28:36 +01:00
Omar Sandoval 8b87811f94 libbtrfsutil: add btrfs_util_subvolume_path()
We can just walk up root backrefs with BTRFS_IOC_TREE_SEARCH and inode
paths with BTRFS_IOC_INO_LOOKUP.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-06 11:28:36 +01:00
Omar Sandoval f676a8ad11 libbtrfsutil: add btrfs_util_create_subvolume()
Doing the ioctl() directly isn't too bad, but passing in a full path is
more convenient than opening the parent and passing the path component.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-06 11:28:36 +01:00
Omar Sandoval 92d4035074 libbtrfsutil: add btrfs_util_is_subvolume() and btrfs_util_subvolume_id()
These are the most trivial helpers in the library and will be used to
implement several of the more involved functions.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-06 11:28:36 +01:00
Omar Sandoval 1b2775bdb0 libbtrfsutil: copy in Btrfs UAPI headers
Systems with older kernels won't have these available, and the copies in
btrfs-progs aren't quite compatible, so for now, let's just copy these
in. We can potentially deduplicate some of this in the future.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-06 11:28:36 +01:00
Omar Sandoval 71d135ef44 libbtrfsutil: fix Python tests
These were broken when the patch series got shuffled around.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-06 11:28:36 +01:00
Omar Sandoval 9615c23d15 libbtrfsutil: add filesystem sync helpers
Namely, sync, start_sync, and wait_sync.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-24 01:37:17 +01:00
Omar Sandoval bad4208da3 libbtrfsutil: add qgroup inheritance helpers
We want to hide struct btrfs_qgroup_inherit from the user because that
comes from the Btrfs UAPI headers. Instead, wrap it in a struct
btrfs_util_qgroup_inherit and provide helpers to manipulate it. This
will be used for subvolume and snapshot creation.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-24 01:37:17 +01:00
Omar Sandoval 23c01b3c1b libbtrfsutil: add Python bindings
The C libbtrfsutil library isn't very useful for scripting, so we also
want bindings for Python. Writing unit tests in Python is also much
easier than doing so in C. Only Python 3 is supported; if someone really
wants Python 2 support, they can write their own bindings. This commit
is just the scaffolding.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-24 01:37:17 +01:00
Omar Sandoval 502e2a3510 Add libbtrfsutil
Currently, users wishing to manage Btrfs filesystems programatically
have to shell out to btrfs-progs and parse the output. This isn't ideal.
The goal of libbtrfsutil is to provide a library version of as many of
the operations of btrfs-progs as possible and to migrate btrfs-progs to
use it.

Rather than simply refactoring the existing btrfs-progs code, the code
has to be written from scratch for a couple of reasons:

* A lot of the btrfs-progs code was not designed with a nice library API
  in mind in terms of reusability, naming, and error reporting.
* libbtrfsutil is licensed under the LGPL, whereas btrfs-progs is under
  the GPL, which makes it dubious to directly copy or move the code.

Eventually, most of the low-level btrfs-progs code should either live in
libbtrfsutil or the shared kernel/userspace filesystem code, and
btrfs-progs will just be the CLI wrapper.

This first commit just includes the build system changes, license,
README, and error reporting helper.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-24 01:37:16 +01:00