Kernel has removed support for this feature in 5.7 so let's remove
support from progs as well.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Subvolume iteration has a window between when we get a root ref (with
BTRFS_IOC_TREE_SEARCH or BTRFS_IOC_GET_SUBVOL_ROOTREF) and when we look
up the path of the parent directory (with BTRFS_IOC_INO_LOOKUP{,_USER}).
If the subvolume is moved or deleted and its old parent directory is
deleted during that window, then BTRFS_IOC_INO_LOOKUP{,_USER} will fail
with ENOENT. The iteration will then fail with ENOENT as well.
We originally encountered this bug with an application that called
`btrfs subvolume show` (which iterates subvolumes to find snapshots) in
parallel with other threads creating and deleting subvolumes. It can be
reproduced almost instantly with the included test cases.
Subvolume iteration should be robust against concurrent modifications to
subvolumes. So, if a subvolume's parent directory no longer exists, just
skip the subvolume, as it must have been deleted or moved elsewhere.
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In file test_filesystem.py the class name should be TestFilesystem, this
looks like a typo and does not affect functionality.
Signed-off-by: David Sterba <dsterba@suse.com>
The caller owns the fd passed to btrfs_util_subvolume_id_fd(), so we
shouldn't close it on error. Fix it, add a regression test, and bump the
library patch version.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I apparently didn't test this on a pre-4.18 kernel.
test_subvolume_info_unprivileged() checks for an ENOTTY, but this
doesn't seem to work correctly with subTest().
test_subvolume_iterator_unprivileged() doesn't have a check at all. Add
an explicit check to both before doing the actual test.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We can use the new BTRFS_IOC_GET_SUBVOL_ROOTREF and
BTRFS_IOC_INO_LOOKUP_USER ioctls to allow non-root users to list
subvolumes.
This is based on a patch from Misono Tomohiro but takes a different
approach (mainly, this approach is more similar to the existing tree
search approach).
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Attempt to use the BTRFS_IOC_GET_SUBVOL_INFO ioctl (added in kernel
4.18) for subvolume_info() if not root. Also, rename
get_subvolume_info_root() -> get_subvolume_info_privileged() for
consistency with further changes.
This is based on a patch from Misono Tomohiro.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Some upcoming tests will need to create a second Btrfs filesystem, so
add support for this to the test helpers.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
These will be used for testing some upcoming changes which allow
unprivileged operations.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We're leaking file descriptors, which makes it impossible to clean up
the temporary mount point created by the test.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
async became a keyword in Python 3.7, so, e.g., create_subvolume('foo',
async=True) is now a syntax error. Fix it with the Python convention of
adding a trailing underscore to the keyword (async -> async_). This is
what several other Python libraries did to handle this.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Right now, we're defaulting to top=5 (i.e, all subvolumes). The
documented default is top=0 (i.e, only beneath the given path). This is
the expected behavior. Fix it and make the test cases cover it.
Reported-by: Jonathan Lemon <bsd@fb.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since "btrfs-progs: mkfs: add uuid and otime to ROOT_ITEM of, FS_TREE",
the top-level subvolume has a non-zero UUID, ctime, and otime. Fix the
subvolume_info() test to not check for zero.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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>
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>
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>
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>
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>
Nikolay Borisov
Omar Sandoval
David Sterba