Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Tejun Heo | 6d66f5c | 2007-09-20 17:31:38 +0900 | [diff] [blame] | 2 | * fs/sysfs/symlink.c - operations for initializing and mounting sysfs |
| 3 | * |
| 4 | * Copyright (c) 2001-3 Patrick Mochel |
| 5 | * Copyright (c) 2007 SUSE Linux Products GmbH |
| 6 | * Copyright (c) 2007 Tejun Heo <teheo@suse.de> |
| 7 | * |
| 8 | * This file is released under the GPLv2. |
| 9 | * |
| 10 | * Please see Documentation/filesystems/sysfs.txt for more information. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | */ |
| 12 | |
| 13 | #define DEBUG |
| 14 | |
| 15 | #include <linux/fs.h> |
| 16 | #include <linux/mount.h> |
| 17 | #include <linux/pagemap.h> |
| 18 | #include <linux/init.h> |
| 19 | |
| 20 | #include "sysfs.h" |
| 21 | |
| 22 | /* Random magic number */ |
| 23 | #define SYSFS_MAGIC 0x62656572 |
| 24 | |
Eric W. Biederman | 7d0c7d6 | 2007-08-20 21:36:30 +0900 | [diff] [blame] | 25 | static struct vfsmount *sysfs_mount; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | struct super_block * sysfs_sb = NULL; |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 27 | struct kmem_cache *sysfs_dir_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | |
Josef 'Jeff' Sipek | ee9b6d6 | 2007-02-12 00:55:41 -0800 | [diff] [blame] | 29 | static const struct super_operations sysfs_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | .statfs = simple_statfs, |
Eric W. Biederman | 90bc613 | 2007-07-31 19:15:08 +0900 | [diff] [blame] | 31 | .drop_inode = generic_delete_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | }; |
| 33 | |
Tejun Heo | 5122503 | 2007-06-14 04:27:25 +0900 | [diff] [blame] | 34 | struct sysfs_dirent sysfs_root = { |
Tejun Heo | dc2f75f | 2007-09-20 16:05:12 +0900 | [diff] [blame] | 35 | .s_name = "", |
Tejun Heo | 13b3086 | 2007-06-14 03:45:14 +0900 | [diff] [blame] | 36 | .s_count = ATOMIC_INIT(1), |
Tejun Heo | dc2f75f | 2007-09-20 16:05:12 +0900 | [diff] [blame] | 37 | .s_flags = SYSFS_DIR, |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 38 | .s_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
Eric Sandeen | dc35125 | 2007-06-11 14:02:45 +0900 | [diff] [blame] | 39 | .s_ino = 1, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | }; |
| 41 | |
| 42 | static int sysfs_fill_super(struct super_block *sb, void *data, int silent) |
| 43 | { |
| 44 | struct inode *inode; |
| 45 | struct dentry *root; |
| 46 | |
| 47 | sb->s_blocksize = PAGE_CACHE_SIZE; |
| 48 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 49 | sb->s_magic = SYSFS_MAGIC; |
| 50 | sb->s_op = &sysfs_ops; |
| 51 | sb->s_time_gran = 1; |
| 52 | sysfs_sb = sb; |
| 53 | |
Tejun Heo | e080e43 | 2007-07-18 14:29:06 +0900 | [diff] [blame] | 54 | /* get root inode, initialize and unlock it */ |
| 55 | inode = sysfs_get_inode(&sysfs_root); |
Tejun Heo | fc9f54b | 2007-06-14 03:45:17 +0900 | [diff] [blame] | 56 | if (!inode) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | pr_debug("sysfs: could not get root inode\n"); |
| 58 | return -ENOMEM; |
| 59 | } |
| 60 | |
Tejun Heo | e080e43 | 2007-07-18 14:29:06 +0900 | [diff] [blame] | 61 | /* instantiate and link root dentry */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | root = d_alloc_root(inode); |
| 63 | if (!root) { |
Harvey Harrison | 8e24eea | 2008-04-30 00:55:09 -0700 | [diff] [blame] | 64 | pr_debug("%s: could not get root dentry!\n",__func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | iput(inode); |
| 66 | return -ENOMEM; |
| 67 | } |
| 68 | root->d_fsdata = &sysfs_root; |
| 69 | sb->s_root = root; |
| 70 | return 0; |
| 71 | } |
| 72 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 73 | static int sysfs_get_sb(struct file_system_type *fs_type, |
| 74 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | { |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 76 | return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | } |
| 78 | |
| 79 | static struct file_system_type sysfs_fs_type = { |
| 80 | .name = "sysfs", |
| 81 | .get_sb = sysfs_get_sb, |
Eric W. Biederman | 0333cd8 | 2007-08-20 21:36:29 +0900 | [diff] [blame] | 82 | .kill_sb = kill_anon_super, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | }; |
| 84 | |
| 85 | int __init sysfs_init(void) |
| 86 | { |
| 87 | int err = -ENOMEM; |
| 88 | |
| 89 | sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache", |
| 90 | sizeof(struct sysfs_dirent), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 91 | 0, 0, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | if (!sysfs_dir_cachep) |
| 93 | goto out; |
| 94 | |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 95 | err = sysfs_inode_init(); |
| 96 | if (err) |
| 97 | goto out_err; |
| 98 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | err = register_filesystem(&sysfs_fs_type); |
| 100 | if (!err) { |
| 101 | sysfs_mount = kern_mount(&sysfs_fs_type); |
| 102 | if (IS_ERR(sysfs_mount)) { |
| 103 | printk(KERN_ERR "sysfs: could not mount!\n"); |
| 104 | err = PTR_ERR(sysfs_mount); |
| 105 | sysfs_mount = NULL; |
| 106 | unregister_filesystem(&sysfs_fs_type); |
| 107 | goto out_err; |
| 108 | } |
| 109 | } else |
| 110 | goto out_err; |
| 111 | out: |
| 112 | return err; |
| 113 | out_err: |
| 114 | kmem_cache_destroy(sysfs_dir_cachep); |
| 115 | sysfs_dir_cachep = NULL; |
| 116 | goto out; |
| 117 | } |