linux-stable/fs/kernfs/mount.c
Tejun Heo c637b8acbe kernfs: s/sysfs/kernfs/ in internal functions and whatever is left
kernfs has just been separated out from sysfs and we're already in
full conflict mode.  Nothing can make the situation any worse.  Let's
take the chance to name things properly.

This patch performs the following renames.

* s/sysfs_*()/kernfs_*()/ in all internal functions
* s/sysfs/kernfs/ in internal strings, comments and whatever is remaining
* Uniformly rename various vfs operations so that they're consistently
  named and distinguishable.

This patch is strictly rename only and doesn't introduce any
functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11 17:39:20 -08:00

165 lines
4.1 KiB
C

/*
* fs/kernfs/mount.c - kernfs mount implementation
*
* Copyright (c) 2001-3 Patrick Mochel
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org>
*
* This file is released under the GPLv2.
*/
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/magic.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include "kernfs-internal.h"
struct kmem_cache *kernfs_node_cache;
static const struct super_operations kernfs_sops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
.evict_inode = kernfs_evict_inode,
};
static int kernfs_fill_super(struct super_block *sb)
{
struct kernfs_super_info *info = kernfs_info(sb);
struct inode *inode;
struct dentry *root;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = SYSFS_MAGIC;
sb->s_op = &kernfs_sops;
sb->s_time_gran = 1;
/* get root inode, initialize and unlock it */
mutex_lock(&kernfs_mutex);
inode = kernfs_get_inode(sb, info->root->kn);
mutex_unlock(&kernfs_mutex);
if (!inode) {
pr_debug("kernfs: could not get root inode\n");
return -ENOMEM;
}
/* instantiate and link root dentry */
root = d_make_root(inode);
if (!root) {
pr_debug("%s: could not get root dentry!\n", __func__);
return -ENOMEM;
}
kernfs_get(info->root->kn);
root->d_fsdata = info->root->kn;
sb->s_root = root;
sb->s_d_op = &kernfs_dops;
return 0;
}
static int kernfs_test_super(struct super_block *sb, void *data)
{
struct kernfs_super_info *sb_info = kernfs_info(sb);
struct kernfs_super_info *info = data;
return sb_info->root == info->root && sb_info->ns == info->ns;
}
static int kernfs_set_super(struct super_block *sb, void *data)
{
int error;
error = set_anon_super(sb, data);
if (!error)
sb->s_fs_info = data;
return error;
}
/**
* kernfs_super_ns - determine the namespace tag of a kernfs super_block
* @sb: super_block of interest
*
* Return the namespace tag associated with kernfs super_block @sb.
*/
const void *kernfs_super_ns(struct super_block *sb)
{
struct kernfs_super_info *info = kernfs_info(sb);
return info->ns;
}
/**
* kernfs_mount_ns - kernfs mount helper
* @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
* @ns: optional namespace tag of the mount
*
* This is to be called from each kernfs user's file_system_type->mount()
* implementation, which should pass through the specified @fs_type and
* @flags, and specify the hierarchy and namespace tag to mount via @root
* and @ns, respectively.
*
* 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, const void *ns)
{
struct super_block *sb;
struct kernfs_super_info *info;
int error;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return ERR_PTR(-ENOMEM);
info->root = root;
info->ns = ns;
sb = sget(fs_type, kernfs_test_super, kernfs_set_super, flags, info);
if (IS_ERR(sb) || sb->s_fs_info != info)
kfree(info);
if (IS_ERR(sb))
return ERR_CAST(sb);
if (!sb->s_root) {
error = kernfs_fill_super(sb);
if (error) {
deactivate_locked_super(sb);
return ERR_PTR(error);
}
sb->s_flags |= MS_ACTIVE;
}
return dget(sb->s_root);
}
/**
* kernfs_kill_sb - kill_sb for kernfs
* @sb: super_block being killed
*
* This can be used directly for file_system_type->kill_sb(). If a kernfs
* user needs extra cleanup, it can implement its own kill_sb() and call
* this function at the end.
*/
void kernfs_kill_sb(struct super_block *sb)
{
struct kernfs_super_info *info = kernfs_info(sb);
struct kernfs_node *root_kn = sb->s_root->d_fsdata;
/*
* Remove the superblock from fs_supers/s_instances
* so we can't find it, before freeing kernfs_super_info.
*/
kill_anon_super(sb);
kfree(info);
kernfs_put(root_kn);
}
void __init kernfs_init(void)
{
kernfs_node_cache = kmem_cache_create("kernfs_node_cache",
sizeof(struct kernfs_node),
0, SLAB_PANIC, NULL);
kernfs_inode_init();
}