From: Jianyu Zhan <nasa4836@gmail.com>
Date: Sat, 26 Apr 2014 07:40:28 +0000 (+0800)
Subject: kernfs: move the last knowledge of sysfs out from kernfs
X-Git-Tag: firefly_0821_release~176^2~3465^2~40^2~1
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=26fc9cd200ec;p=firefly-linux-kernel-4.4.55.git
kernfs: move the last knowledge of sysfs out from kernfs
There is still one residue of sysfs remaining: the sb_magic
SYSFS_MAGIC. However this should be kernfs user specific,
so this patch moves it out. Kerrnfs user should specify their
magic number while mouting.
Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index f25a7c0c3cdc..d171b98a6cdd 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -62,7 +62,7 @@ struct kernfs_root *kernfs_root_from_sb(struct super_block *sb)
return NULL;
}
-static int kernfs_fill_super(struct super_block *sb)
+static int kernfs_fill_super(struct super_block *sb, unsigned long magic)
{
struct kernfs_super_info *info = kernfs_info(sb);
struct inode *inode;
@@ -71,7 +71,7 @@ static int kernfs_fill_super(struct super_block *sb)
info->sb = sb;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
- sb->s_magic = SYSFS_MAGIC;
+ sb->s_magic = magic;
sb->s_op = &kernfs_sops;
sb->s_time_gran = 1;
@@ -132,6 +132,7 @@ const void *kernfs_super_ns(struct super_block *sb)
* @fs_type: file_system_type of the fs being mounted
* @flags: mount flags specified for the mount
* @root: kernfs_root of the hierarchy being mounted
+ * @magic: file system specific magic number
* @new_sb_created: tell the caller if we allocated a new superblock
* @ns: optional namespace tag of the mount
*
@@ -143,8 +144,8 @@ const void *kernfs_super_ns(struct super_block *sb)
* The return value can be passed to the vfs layer verbatim.
*/
struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
- struct kernfs_root *root, bool *new_sb_created,
- const void *ns)
+ struct kernfs_root *root, unsigned long magic,
+ bool *new_sb_created, const void *ns)
{
struct super_block *sb;
struct kernfs_super_info *info;
@@ -169,7 +170,7 @@ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
if (!sb->s_root) {
struct kernfs_super_info *info = kernfs_info(sb);
- error = kernfs_fill_super(sb);
+ error = kernfs_fill_super(sb, magic);
if (error) {
deactivate_locked_super(sb);
return ERR_PTR(error);
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 8794423f7efb..8a49486bf30c 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -13,6 +13,7 @@
#define DEBUG
#include <linux/fs.h>
+#include <linux/magic.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/user_namespace.h>
@@ -38,7 +39,8 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type,
}
ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
- root = kernfs_mount_ns(fs_type, flags, sysfs_root, &new_sb, ns);
+ root = kernfs_mount_ns(fs_type, flags, sysfs_root,
+ SYSFS_MAGIC, &new_sb, ns);
if (IS_ERR(root) || !new_sb)
kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
return root;
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index c841688a78a3..17aa1cce6f8e 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -301,8 +301,8 @@ void kernfs_notify(struct kernfs_node *kn);
const void *kernfs_super_ns(struct super_block *sb);
struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
- struct kernfs_root *root, bool *new_sb_created,
- const void *ns);
+ struct kernfs_root *root, unsigned long magic,
+ bool *new_sb_created, const void *ns);
void kernfs_kill_sb(struct super_block *sb);
void kernfs_init(void);
@@ -395,7 +395,8 @@ static inline const void *kernfs_super_ns(struct super_block *sb)
static inline struct dentry *
kernfs_mount_ns(struct file_system_type *fs_type, int flags,
- struct kernfs_root *root, bool *new_sb_created, const void *ns)
+ struct kernfs_root *root, unsigned long magic,
+ bool *new_sb_created, const void *ns)
{ return ERR_PTR(-ENOSYS); }
static inline void kernfs_kill_sb(struct super_block *sb) { }
@@ -453,9 +454,11 @@ static inline int kernfs_rename(struct kernfs_node *kn,
static inline struct dentry *
kernfs_mount(struct file_system_type *fs_type, int flags,
- struct kernfs_root *root, bool *new_sb_created)
+ struct kernfs_root *root, unsigned long magic,
+ bool *new_sb_created)
{
- return kernfs_mount_ns(fs_type, flags, root, new_sb_created, NULL);
+ return kernfs_mount_ns(fs_type, flags, root,
+ magic, new_sb_created, NULL);
}
#endif /* __LINUX_KERNFS_H */
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 3f1ca934a237..ceee0c54c6a4 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -33,6 +33,7 @@
#include <linux/init_task.h>
#include <linux/kernel.h>
#include <linux/list.h>
+#include <linux/magic.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/mount.h>
@@ -1604,7 +1605,8 @@ out_unlock:
if (ret)
return ERR_PTR(ret);
- dentry = kernfs_mount(fs_type, flags, root->kf_root, &new_sb);
+ dentry = kernfs_mount(fs_type, flags, root->kf_root,
+ CGROUP_SUPER_MAGIC, &new_sb);
if (IS_ERR(dentry) || !new_sb)
cgroup_put(&root->cgrp);
return dentry;