We also support recursive deletion using a subvolume iterator.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Thanks to subvolume iterators, we can also implement recursive snapshot
fairly easily.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is how we can implement stuff like `btrfs subvol list`. Rather than
producing the entire list upfront, the iterator approach uses less
memory in the common case where the whole list is not stored (O(max
subvolume path length)). It supports both pre-order traversal (useful
for, e.g, recursive snapshot) and post-order traversal (useful for
recursive delete).
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
set_default_subvolume() is a trivial ioctl(), but there's no ioctl() for
get_default_subvolume(), so we need to search the root tree.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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>
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>
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>
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>
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>
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>
Omar Sandoval