mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-10-31 09:36:25 +00:00
d8c76e6f45
This is mostly included for parity with dec_nlink(), where we will have some more hooks. This one should stay pretty darn straightforward for now. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
110 lines
2.4 KiB
C
110 lines
2.4 KiB
C
/*
|
|
* mount.c - operations for initializing and mounting sysfs.
|
|
*/
|
|
|
|
#define DEBUG
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/init.h>
|
|
|
|
#include "sysfs.h"
|
|
|
|
/* Random magic number */
|
|
#define SYSFS_MAGIC 0x62656572
|
|
|
|
struct vfsmount *sysfs_mount;
|
|
struct super_block * sysfs_sb = NULL;
|
|
kmem_cache_t *sysfs_dir_cachep;
|
|
|
|
static struct super_operations sysfs_ops = {
|
|
.statfs = simple_statfs,
|
|
.drop_inode = generic_delete_inode,
|
|
};
|
|
|
|
static struct sysfs_dirent sysfs_root = {
|
|
.s_sibling = LIST_HEAD_INIT(sysfs_root.s_sibling),
|
|
.s_children = LIST_HEAD_INIT(sysfs_root.s_children),
|
|
.s_element = NULL,
|
|
.s_type = SYSFS_ROOT,
|
|
.s_iattr = NULL,
|
|
};
|
|
|
|
static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
|
|
{
|
|
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 = &sysfs_ops;
|
|
sb->s_time_gran = 1;
|
|
sysfs_sb = sb;
|
|
|
|
inode = sysfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
|
|
&sysfs_root);
|
|
if (inode) {
|
|
inode->i_op = &sysfs_dir_inode_operations;
|
|
inode->i_fop = &sysfs_dir_operations;
|
|
/* directory inodes start off with i_nlink == 2 (for "." entry) */
|
|
inc_nlink(inode);
|
|
} else {
|
|
pr_debug("sysfs: could not get root inode\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
root = d_alloc_root(inode);
|
|
if (!root) {
|
|
pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
|
|
iput(inode);
|
|
return -ENOMEM;
|
|
}
|
|
root->d_fsdata = &sysfs_root;
|
|
sb->s_root = root;
|
|
return 0;
|
|
}
|
|
|
|
static int sysfs_get_sb(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
|
|
{
|
|
return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt);
|
|
}
|
|
|
|
static struct file_system_type sysfs_fs_type = {
|
|
.name = "sysfs",
|
|
.get_sb = sysfs_get_sb,
|
|
.kill_sb = kill_litter_super,
|
|
};
|
|
|
|
int __init sysfs_init(void)
|
|
{
|
|
int err = -ENOMEM;
|
|
|
|
sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
|
|
sizeof(struct sysfs_dirent),
|
|
0, 0, NULL, NULL);
|
|
if (!sysfs_dir_cachep)
|
|
goto out;
|
|
|
|
err = register_filesystem(&sysfs_fs_type);
|
|
if (!err) {
|
|
sysfs_mount = kern_mount(&sysfs_fs_type);
|
|
if (IS_ERR(sysfs_mount)) {
|
|
printk(KERN_ERR "sysfs: could not mount!\n");
|
|
err = PTR_ERR(sysfs_mount);
|
|
sysfs_mount = NULL;
|
|
unregister_filesystem(&sysfs_fs_type);
|
|
goto out_err;
|
|
}
|
|
} else
|
|
goto out_err;
|
|
out:
|
|
return err;
|
|
out_err:
|
|
kmem_cache_destroy(sysfs_dir_cachep);
|
|
sysfs_dir_cachep = NULL;
|
|
goto out;
|
|
}
|