The test cli-tests/008-subvolume-get-set-default fails when compiled
with 'D=ubsan', the access to search header items does not follow the
type alignment, so use the accessors.
The error:
subvolume get-default: default id is not 256, but
libbtrfsutil/subvolume.c:361:13: runtime error: member access within
misaligned address 0x7ffc147e4b6f for type 'const struct
btrfs_ioctl_search_header', which requires 8 byte alignment
Note that using the accessors does not fix the ubsan warning, as it
warns on taking the address of a member whose _base_ type is unaligned,
ie. it's the 'sh'.
Fixing that would need to play tricks with pointers to do &sh->type
manually, but to avoid triggering ubsan.
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>
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>
Factor out main logic of btrfs_util_subvolume_info_fd(). This is a
preparation work to relax the root privilege of this function. No
functional changes.
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we fail to reallocate the ID array, we still need to free it.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Deleted free space cache inodes also get an orphan item in the root
tree, but we shouldn't report those as deleted subvolumes. Deleted
subvolumes will still have the root item, so we can just do an extra
tree search.
Reported-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Omar Sandoval <osandov@fb.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>
David Sterba