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| author | Tejun Heo <tj@kernel.org> | 2014-02-03 14:09:15 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-07 16:00:41 -0800 |
| commit | 0c23b2259a4850494e2c53e864ea840597c6cdd3 (patch) | |
| tree | f4d061ea433e443edd43d1f0a186e06aeb2ed95e /fs/kernfs | |
| parent | 2536390da0d300b2734c721235c082498879841d (diff) | |
| download | linux-0c23b2259a4850494e2c53e864ea840597c6cdd3.tar.gz linux-0c23b2259a4850494e2c53e864ea840597c6cdd3.tar.bz2 linux-0c23b2259a4850494e2c53e864ea840597c6cdd3.zip | |
kernfs: implement kernfs_node_from_dentry(), kernfs_root_from_sb() and kernfs_rename()
Implement helpers to determine node from dentry and root from
super_block. Also add a kernfs_rename_ns() wrapper which assumes NULL
namespace. These generally make sense and will be used by cgroup.
v2: Some dummy implementations for !CONFIG_SYSFS was missing. Fixed.
Reported by kbuild test robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/kernfs')
| -rw-r--r-- | fs/kernfs/dir.c | 18 | ||||
| -rw-r--r-- | fs/kernfs/mount.c | 14 |
2 files changed, 32 insertions, 0 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 3cff0a233cd1..42a250f83b98 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -350,6 +350,24 @@ const struct dentry_operations kernfs_dops = { .d_release = kernfs_dop_release, }; +/** + * kernfs_node_from_dentry - determine kernfs_node associated with a dentry + * @dentry: the dentry in question + * + * Return the kernfs_node associated with @dentry. If @dentry is not a + * kernfs one, %NULL is returned. + * + * While the returned kernfs_node will stay accessible as long as @dentry + * is accessible, the returned node can be in any state and the caller is + * fully responsible for determining what's accessible. + */ +struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry) +{ + if (dentry->d_op == &kernfs_dops) + return dentry->d_fsdata; + return NULL; +} + static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, const char *name, umode_t mode, unsigned flags) diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 70cc6983d9b5..e5b28b0ebc37 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -48,6 +48,20 @@ static const struct super_operations kernfs_sops = { .show_options = kernfs_sop_show_options, }; +/** + * kernfs_root_from_sb - determine kernfs_root associated with a super_block + * @sb: the super_block in question + * + * Return the kernfs_root associated with @sb. If @sb is not a kernfs one, + * %NULL is returned. + */ +struct kernfs_root *kernfs_root_from_sb(struct super_block *sb) +{ + if (sb->s_op == &kernfs_sops) + return kernfs_info(sb)->root; + return NULL; +} + static int kernfs_fill_super(struct super_block *sb) { struct kernfs_super_info *info = kernfs_info(sb); |