GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-26 00:21:17 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

kernfs: implement kernfs_root->supers list

Browse source 
Currently, there's no way to find out which super_blocks are
associated with a given kernfs_root.  Let's implement it - the planned
inotify extension to kernfs_notify() needs it.

Make kernfs_super_info point back to the super_block and chain it at
kernfs_root->supers.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tejun Heo 2014-04-09 11:07:30 -04:00 • committed by Greg Kroah-Hartman
parent a798c10faf
commit 7d568a8383
4 changed files with 21 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

1
fs/kernfs/dir.c
View file

@ -711,6 +711,7 @@ struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops,
return ERR_PTR(-ENOMEM); return ERR_PTR(-ENOMEM);
ida_init(&root->ino_ida); ida_init(&root->ino_ida);
INIT_LIST_HEAD(&root->supers);
kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO,
KERNFS_DIR); KERNFS_DIR);

5
fs/kernfs/kernfs-internal.h
View file

@ -49,6 +49,8 @@ static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
* mount.c * mount.c
*/ */
struct kernfs_super_info { struct kernfs_super_info {
struct super_block *sb;
/* /*
* The root associated with this super_block. Each super_block is * The root associated with this super_block. Each super_block is
* identified by the root and ns it's associated with. * identified by the root and ns it's associated with.
@ -62,6 +64,9 @@ struct kernfs_super_info {
* an array and compare kernfs_node tag against every entry. * an array and compare kernfs_node tag against every entry.
*/ */
const void *ns; const void *ns;
/* anchored at kernfs_root->supers, protected by kernfs_mutex */
struct list_head node;
}; };
#define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info)) #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))

11
fs/kernfs/mount.c
View file

@ -68,6 +68,7 @@ static int kernfs_fill_super(struct super_block *sb)
struct inode *inode; struct inode *inode;
struct dentry *root; struct dentry *root;
info->sb = sb;
sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT; sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = SYSFS_MAGIC; sb->s_magic = SYSFS_MAGIC;
@ -166,12 +167,18 @@ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
*new_sb_created = !sb->s_root; *new_sb_created = !sb->s_root;
if (!sb->s_root) { if (!sb->s_root) {
struct kernfs_super_info *info = kernfs_info(sb);
error = kernfs_fill_super(sb); error = kernfs_fill_super(sb);
if (error) { if (error) {
deactivate_locked_super(sb); deactivate_locked_super(sb);
return ERR_PTR(error); return ERR_PTR(error);
} }
sb->s_flags |= MS_ACTIVE; sb->s_flags |= MS_ACTIVE;
mutex_lock(&kernfs_mutex);
list_add(&info->node, &root->supers);
mutex_unlock(&kernfs_mutex);
} }
return dget(sb->s_root); return dget(sb->s_root);
@ -190,6 +197,10 @@ void kernfs_kill_sb(struct super_block *sb)
struct kernfs_super_info *info = kernfs_info(sb); struct kernfs_super_info *info = kernfs_info(sb);
struct kernfs_node *root_kn = sb->s_root->d_fsdata; struct kernfs_node *root_kn = sb->s_root->d_fsdata;
mutex_lock(&kernfs_mutex);
list_del(&info->node);
mutex_unlock(&kernfs_mutex);
/* /*
* Remove the superblock from fs_supers/s_instances * Remove the superblock from fs_supers/s_instances
* so we can't find it, before freeing kernfs_super_info. * so we can't find it, before freeing kernfs_super_info.

4
include/linux/kernfs.h
View file

@ -144,6 +144,10 @@ struct kernfs_root {
/* private fields, do not use outside kernfs proper */ /* private fields, do not use outside kernfs proper */
struct ida ino_ida; struct ida ino_ida;
struct kernfs_syscall_ops *syscall_ops; struct kernfs_syscall_ops *syscall_ops;
/* list of kernfs_super_info of this root, protected by kernfs_mutex */
struct list_head supers;
wait_queue_head_t deactivate_waitq; wait_queue_head_t deactivate_waitq;
}; };