From c9482a5bdcc09be9096f40e858c5fe39c389cd52 Mon Sep 17 00:00:00 2001 From: Jianyu Zhan Date: Sat, 26 Apr 2014 15:40:28 +0800 Subject: [PATCH] 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 Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds --- fs/kernfs/mount.c | 11 ++++++----- fs/sysfs/mount.c | 4 +++- include/linux/kernfs.h | 13 ++++++++----- kernel/cgroup.c | 4 +++- 4 files changed, 20 insertions(+), 12 deletions(-) diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 6a5f04a..95dcd1d 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; @@ -70,7 +70,7 @@ static int kernfs_fill_super(struct super_block *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; @@ -131,6 +131,7 @@ 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 * @@ -142,8 +143,8 @@ 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; @@ -166,7 +167,7 @@ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, *new_sb_created = !sb->s_root; if (!sb->s_root) { - 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 8794423..8a49486 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -13,6 +13,7 @@ #define DEBUG #include +#include #include #include #include @@ -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 ca1be5c..52bf567 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -297,8 +297,8 @@ 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); @@ -391,7 +391,8 @@ 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) { } @@ -449,9 +450,11 @@ 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 3f1ca93..ceee0c5 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -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; -- 1.9.1