This patch implements functionality of following ioctls:
BTRFS_IOC_INO_LOOKUP - Reading tree root id and path
Read tree root id and path for a given file or directory.
The name and tree root id are returned in an ioctl's third
argument that represents a pointer to a following type:
struct btrfs_ioctl_ino_lookup_args {
__u64 treeid;
__u64 objectid;
char name[BTRFS_INO_LOOKUP_PATH_MAX];
};
Before calling this ioctl, field 'objectid' should be filled
with the object id value for which the tree id and path are
to be read. Value 'BTRFS_FIRST_FREE_OBJECTID' represents the
object id for the first available btrfs object (directory or
file).
BTRFS_IOC_INO_PATHS - Reading paths to all files
Read path to all files with a certain inode number. The paths
are returned in the ioctl's third argument which represents
a pointer to a following type:
struct btrfs_ioctl_ino_path_args {
__u64 inum; /* in */
__u64 size; /* in */
__u64 reserved[4];
/* struct btrfs_data_container *fspath; out */
__u64 fspath; /* out */
};
Before calling this ioctl, the 'inum' and 'size' field should
be filled with the aproppriate inode number and size of the
directory where file paths should be looked for. For now, the
paths are returned in an '__u64' (unsigned long long) value
'fspath'.
BTRFS_IOC_LOGICAL_INO - Reading inode numbers
Read inode numbers for files on a certain logical adress. The
inode numbers are returned in the ioctl's third argument which
represents a pointer to a following type:
struct btrfs_ioctl_logical_ino_args {
__u64 logical; /* in */
__u64 size; /* in */
__u64 reserved[3]; /* must be 0 for now */
__u64 flags; /* in, v2 only */
/* struct btrfs_data_container *inodes; out */
__u64 inodes;
};
Before calling this ioctl, the 'logical' and 'size' field should
be filled with the aproppriate logical adress and size of where
the inode numbers of files should be looked for. For now, the
inode numbers are returned in an '__u64' (unsigned long long)
value 'inodes'.
BTRFS_IOC_LOGICAL_INO_V2 - Reading inode numbers
Same as the above mentioned ioctl except that it allows passing
a flags 'BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET'.
BTRFS_IOC_INO_LOOKUP_USER - Reading subvolume name and path
Read name and path of a subvolume. The tree root id and
path are read in an ioctl's third argument which represents a
pointer to a following type:
struct btrfs_ioctl_ino_lookup_user_args {
/* in, inode number containing the subvolume of 'subvolid' */
__u64 dirid;
/* in */
__u64 treeid;
/* out, name of the subvolume of 'treeid' */
char name[BTRFS_VOL_NAME_MAX + 1];
/*
* out, constructed path from the directory with which the ioctl is
* called to dirid
*/
char path[BTRFS_INO_LOOKUP_USER_PATH_MAX];
};
Before calling this ioctl, the 'dirid' and 'treeid' field should
be filled with aproppriate values which represent the inode number
of the directory that contains the subvolume and treeid of the
subvolume.
Implementation notes:
All of the ioctls in this patch use structure types as third arguments.
That is the reason why aproppriate thunk definitions were added in file
'syscall_types.h'.
Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Tested-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200823195014.116226-6-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
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