diff options
| author |   Shaohua Li <shli@fb.com> | 2017-07-12 11:49:51 -0700 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2017-07-29 09:00:03 -0600 |
| commit | aa8188253474b4053bc2900d9fcb545ce68bdf5c (patch) | |
| tree | 7d7afd563e9f2cd46cf8c0a0299aab42fcf764e9 /include | |
| parent | kernfs: introduce kernfs_node_id (diff) | |
| download | linux-dev-aa8188253474b4053bc2900d9fcb545ce68bdf5c.tar.xz linux-dev-aa8188253474b4053bc2900d9fcb545ce68bdf5c.zip | |
kernfs: add exportfs operations
Now we have the facilities to implement exportfs operations. The idea is
cgroup can export the fhandle info to userspace, then userspace uses
fhandle to find the cgroup name. Another example is userspace can get
fhandle for a cgroup and BPF uses the fhandle to filter info for the
cgroup.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/kernfs.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 06a0c5913e1d..d149361e5875 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -69,6 +69,12 @@ enum kernfs_root_flag { * following flag enables that behavior. */ KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK = 0x0002, + + /* + * The filesystem supports exportfs operation, so userspace can use + * fhandle to access nodes of the fs. + */ + KERNFS_ROOT_SUPPORT_EXPORTOP = 0x0004, }; /* type-specific structures for kernfs_node union members */ @@ -98,6 +104,12 @@ struct kernfs_elem_attr { /* represent a kernfs node */ union kernfs_node_id { struct { + /* + * blktrace will export this struct as a simplified 'struct + * fid' (which is a big data struction), so userspace can use + * it to find kernfs node. The layout must match the first two + * fields of 'struct fid' exactly. + */ u32 ino; u32 generation; }; |