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author | Eric W. Biederman <ebiederm@xmission.com> | 2015-05-13 16:31:40 -0500 |
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committer | Luis Henriques <luis.henriques@canonical.com> | 2015-07-15 10:01:07 +0100 |
commit | ccf3400764f8f43875261d25a899c5966f171c01 (patch) | |
tree | da663ce1f118ead4bf7c54dda39c1460528c81a4 /fs | |
parent | 4e6378f17c02560f052a0fae6e7c2fc1647d06ba (diff) | |
download | linux-stable-ccf3400764f8f43875261d25a899c5966f171c01.tar.gz linux-stable-ccf3400764f8f43875261d25a899c5966f171c01.tar.bz2 linux-stable-ccf3400764f8f43875261d25a899c5966f171c01.zip |
sysfs: Add support for permanently empty directories to serve as mount points.
commit 87d2846fcf88113fae2341da1ca9a71f0d916f2c upstream.
Add two functions sysfs_create_mount_point and
sysfs_remove_mount_point that hang a permanently empty directory off
of a kobject or remove a permanently emptpy directory hanging from a
kobject. Export these new functions so modular filesystems can use
them.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/sysfs/dir.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 0b45ff42f374..94374e435025 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -121,3 +121,37 @@ int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, return kernfs_rename_ns(kn, new_parent, kn->name, new_ns); } + +/** + * sysfs_create_mount_point - create an always empty directory + * @parent_kobj: kobject that will contain this always empty directory + * @name: The name of the always empty directory to add + */ +int sysfs_create_mount_point(struct kobject *parent_kobj, const char *name) +{ + struct kernfs_node *kn, *parent = parent_kobj->sd; + + kn = kernfs_create_empty_dir(parent, name); + if (IS_ERR(kn)) { + if (PTR_ERR(kn) == -EEXIST) + sysfs_warn_dup(parent, name); + return PTR_ERR(kn); + } + + return 0; +} +EXPORT_SYMBOL_GPL(sysfs_create_mount_point); + +/** + * sysfs_remove_mount_point - remove an always empty directory. + * @parent_kobj: kobject that will contain this always empty directory + * @name: The name of the always empty directory to remove + * + */ +void sysfs_remove_mount_point(struct kobject *parent_kobj, const char *name) +{ + struct kernfs_node *parent = parent_kobj->sd; + + kernfs_remove_by_name_ns(parent, name, NULL); +} +EXPORT_SYMBOL_GPL(sysfs_remove_mount_point); |