Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
authored by
Jianyu Zhan
and committed by
Linus Torvalds
c9482a5b
cae61ba3
+20
-12
+6
-5
fs/kernfs/mount.c
+6
-5
fs/kernfs/mount.c
···
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return NULL;
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}
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-
static int kernfs_fill_super(struct super_block *sb)
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+
static int kernfs_fill_super(struct super_block *sb, unsigned long magic)
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{
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struct kernfs_super_info *info = kernfs_info(sb);
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struct inode *inode;
···
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sb->s_blocksize = PAGE_CACHE_SIZE;
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sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
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-
sb->s_magic = SYSFS_MAGIC;
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+
sb->s_magic = magic;
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sb->s_op = &kernfs_sops;
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sb->s_time_gran = 1;
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···
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* @fs_type: file_system_type of the fs being mounted
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* @flags: mount flags specified for the mount
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* @root: kernfs_root of the hierarchy being mounted
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+
* @magic: file system specific magic number
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* @new_sb_created: tell the caller if we allocated a new superblock
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* @ns: optional namespace tag of the mount
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*
···
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* The return value can be passed to the vfs layer verbatim.
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*/
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struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
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-
struct kernfs_root *root, bool *new_sb_created,
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-
const void *ns)
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struct kernfs_root *root, unsigned long magic,
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+
bool *new_sb_created, const void *ns)
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{
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struct super_block *sb;
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struct kernfs_super_info *info;
···
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*new_sb_created = !sb->s_root;
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if (!sb->s_root) {
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-
error = kernfs_fill_super(sb);
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+
error = kernfs_fill_super(sb, magic);
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if (error) {
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deactivate_locked_super(sb);
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return ERR_PTR(error);
+3
-1
fs/sysfs/mount.c
+3
-1
fs/sysfs/mount.c
···
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#define DEBUG
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#include <linux/fs.h>
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+
#include <linux/magic.h>
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#include <linux/mount.h>
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#include <linux/init.h>
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#include <linux/user_namespace.h>
···
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}
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ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
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-
root = kernfs_mount_ns(fs_type, flags, sysfs_root, &new_sb, ns);
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+
root = kernfs_mount_ns(fs_type, flags, sysfs_root,
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+
SYSFS_MAGIC, &new_sb, ns);
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if (IS_ERR(root) || !new_sb)
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kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
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return root;
+8
-5
include/linux/kernfs.h
+8
-5
include/linux/kernfs.h
···
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const void *kernfs_super_ns(struct super_block *sb);
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struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
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-
struct kernfs_root *root, bool *new_sb_created,
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-
const void *ns);
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+
struct kernfs_root *root, unsigned long magic,
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bool *new_sb_created, const void *ns);
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void kernfs_kill_sb(struct super_block *sb);
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void kernfs_init(void);
···
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static inline struct dentry *
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kernfs_mount_ns(struct file_system_type *fs_type, int flags,
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-
struct kernfs_root *root, bool *new_sb_created, const void *ns)
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+
struct kernfs_root *root, unsigned long magic,
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+
bool *new_sb_created, const void *ns)
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{ return ERR_PTR(-ENOSYS); }
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static inline void kernfs_kill_sb(struct super_block *sb) { }
···
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static inline struct dentry *
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kernfs_mount(struct file_system_type *fs_type, int flags,
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-
struct kernfs_root *root, bool *new_sb_created)
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+
struct kernfs_root *root, unsigned long magic,
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bool *new_sb_created)
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{
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-
return kernfs_mount_ns(fs_type, flags, root, new_sb_created, NULL);
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+
return kernfs_mount_ns(fs_type, flags, root,
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+
magic, new_sb_created, NULL);
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}
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#endif /* __LINUX_KERNFS_H */
+3
-1
kernel/cgroup.c
+3
-1
kernel/cgroup.c
···
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#include <linux/init_task.h>
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/magic.h>
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#include <linux/mm.h>
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#include <linux/mutex.h>
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#include <linux/mount.h>
···
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if (ret)
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return ERR_PTR(ret);
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-
dentry = kernfs_mount(fs_type, flags, root->kf_root, &new_sb);
1607
+
dentry = kernfs_mount(fs_type, flags, root->kf_root,
1608
+
CGROUP_SUPER_MAGIC, &new_sb);
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if (IS_ERR(dentry) || !new_sb)
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cgroup_put(&root->cgrp);
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return dentry;