Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/proc/inode.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/time.h> | |
8 | #include <linux/proc_fs.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/string.h> | |
12 | #include <linux/stat.h> | |
13 | #include <linux/file.h> | |
14 | #include <linux/limits.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/smp_lock.h> | |
18 | ||
19 | #include <asm/system.h> | |
20 | #include <asm/uaccess.h> | |
21 | ||
fee781e6 | 22 | #include "internal.h" |
1da177e4 LT |
23 | |
24 | static inline struct proc_dir_entry * de_get(struct proc_dir_entry *de) | |
25 | { | |
26 | if (de) | |
27 | atomic_inc(&de->count); | |
28 | return de; | |
29 | } | |
30 | ||
31 | /* | |
32 | * Decrements the use count and checks for deferred deletion. | |
33 | */ | |
34 | static void de_put(struct proc_dir_entry *de) | |
35 | { | |
36 | if (de) { | |
37 | lock_kernel(); | |
38 | if (!atomic_read(&de->count)) { | |
39 | printk("de_put: entry %s already free!\n", de->name); | |
40 | unlock_kernel(); | |
41 | return; | |
42 | } | |
43 | ||
44 | if (atomic_dec_and_test(&de->count)) { | |
45 | if (de->deleted) { | |
46 | printk("de_put: deferred delete of %s\n", | |
47 | de->name); | |
48 | free_proc_entry(de); | |
49 | } | |
50 | } | |
51 | unlock_kernel(); | |
52 | } | |
53 | } | |
54 | ||
55 | /* | |
56 | * Decrement the use count of the proc_dir_entry. | |
57 | */ | |
58 | static void proc_delete_inode(struct inode *inode) | |
59 | { | |
60 | struct proc_dir_entry *de; | |
1da177e4 | 61 | |
fef26658 MF |
62 | truncate_inode_pages(&inode->i_data, 0); |
63 | ||
99f89551 | 64 | /* Stop tracking associated processes */ |
13b41b09 | 65 | put_pid(PROC_I(inode)->pid); |
1da177e4 LT |
66 | |
67 | /* Let go of any associated proc directory entry */ | |
68 | de = PROC_I(inode)->pde; | |
69 | if (de) { | |
70 | if (de->owner) | |
71 | module_put(de->owner); | |
72 | de_put(de); | |
73 | } | |
74 | clear_inode(inode); | |
75 | } | |
76 | ||
77 | struct vfsmount *proc_mnt; | |
78 | ||
79 | static void proc_read_inode(struct inode * inode) | |
80 | { | |
81 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
82 | } | |
83 | ||
e18b890b | 84 | static struct kmem_cache * proc_inode_cachep; |
1da177e4 LT |
85 | |
86 | static struct inode *proc_alloc_inode(struct super_block *sb) | |
87 | { | |
88 | struct proc_inode *ei; | |
89 | struct inode *inode; | |
90 | ||
e94b1766 | 91 | ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
92 | if (!ei) |
93 | return NULL; | |
13b41b09 | 94 | ei->pid = NULL; |
aed7a6c4 | 95 | ei->fd = 0; |
1da177e4 LT |
96 | ei->op.proc_get_link = NULL; |
97 | ei->pde = NULL; | |
98 | inode = &ei->vfs_inode; | |
99 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
100 | return inode; | |
101 | } | |
102 | ||
103 | static void proc_destroy_inode(struct inode *inode) | |
104 | { | |
105 | kmem_cache_free(proc_inode_cachep, PROC_I(inode)); | |
106 | } | |
107 | ||
e18b890b | 108 | static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) |
1da177e4 LT |
109 | { |
110 | struct proc_inode *ei = (struct proc_inode *) foo; | |
111 | ||
112 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
113 | SLAB_CTOR_CONSTRUCTOR) | |
114 | inode_init_once(&ei->vfs_inode); | |
115 | } | |
116 | ||
117 | int __init proc_init_inodecache(void) | |
118 | { | |
119 | proc_inode_cachep = kmem_cache_create("proc_inode_cache", | |
120 | sizeof(struct proc_inode), | |
fffb60f9 PJ |
121 | 0, (SLAB_RECLAIM_ACCOUNT| |
122 | SLAB_MEM_SPREAD), | |
1da177e4 LT |
123 | init_once, NULL); |
124 | if (proc_inode_cachep == NULL) | |
125 | return -ENOMEM; | |
126 | return 0; | |
127 | } | |
128 | ||
129 | static int proc_remount(struct super_block *sb, int *flags, char *data) | |
130 | { | |
131 | *flags |= MS_NODIRATIME; | |
132 | return 0; | |
133 | } | |
134 | ||
135 | static struct super_operations proc_sops = { | |
136 | .alloc_inode = proc_alloc_inode, | |
137 | .destroy_inode = proc_destroy_inode, | |
138 | .read_inode = proc_read_inode, | |
139 | .drop_inode = generic_delete_inode, | |
140 | .delete_inode = proc_delete_inode, | |
141 | .statfs = simple_statfs, | |
142 | .remount_fs = proc_remount, | |
143 | }; | |
144 | ||
145 | struct inode *proc_get_inode(struct super_block *sb, unsigned int ino, | |
146 | struct proc_dir_entry *de) | |
147 | { | |
148 | struct inode * inode; | |
149 | ||
150 | /* | |
151 | * Increment the use count so the dir entry can't disappear. | |
152 | */ | |
153 | de_get(de); | |
154 | ||
155 | WARN_ON(de && de->deleted); | |
156 | ||
e9543659 KK |
157 | if (de != NULL && !try_module_get(de->owner)) |
158 | goto out_mod; | |
159 | ||
1da177e4 LT |
160 | inode = iget(sb, ino); |
161 | if (!inode) | |
e9543659 KK |
162 | goto out_ino; |
163 | ||
1da177e4 LT |
164 | PROC_I(inode)->pde = de; |
165 | if (de) { | |
166 | if (de->mode) { | |
167 | inode->i_mode = de->mode; | |
168 | inode->i_uid = de->uid; | |
169 | inode->i_gid = de->gid; | |
170 | } | |
171 | if (de->size) | |
172 | inode->i_size = de->size; | |
173 | if (de->nlink) | |
174 | inode->i_nlink = de->nlink; | |
1da177e4 LT |
175 | if (de->proc_iops) |
176 | inode->i_op = de->proc_iops; | |
177 | if (de->proc_fops) | |
178 | inode->i_fop = de->proc_fops; | |
179 | } | |
180 | ||
1da177e4 LT |
181 | return inode; |
182 | ||
e9543659 KK |
183 | out_ino: |
184 | if (de != NULL) | |
185 | module_put(de->owner); | |
186 | out_mod: | |
1da177e4 | 187 | de_put(de); |
e9543659 | 188 | return NULL; |
1da177e4 LT |
189 | } |
190 | ||
191 | int proc_fill_super(struct super_block *s, void *data, int silent) | |
192 | { | |
193 | struct inode * root_inode; | |
194 | ||
92d03285 | 195 | s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC; |
1da177e4 LT |
196 | s->s_blocksize = 1024; |
197 | s->s_blocksize_bits = 10; | |
198 | s->s_magic = PROC_SUPER_MAGIC; | |
199 | s->s_op = &proc_sops; | |
200 | s->s_time_gran = 1; | |
201 | ||
202 | root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root); | |
203 | if (!root_inode) | |
204 | goto out_no_root; | |
1da177e4 LT |
205 | root_inode->i_uid = 0; |
206 | root_inode->i_gid = 0; | |
207 | s->s_root = d_alloc_root(root_inode); | |
208 | if (!s->s_root) | |
209 | goto out_no_root; | |
210 | return 0; | |
211 | ||
212 | out_no_root: | |
213 | printk("proc_read_super: get root inode failed\n"); | |
214 | iput(root_inode); | |
215 | return -ENOMEM; | |
216 | } | |
217 | MODULE_LICENSE("GPL"); |