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 | ||
22 | extern void free_proc_entry(struct proc_dir_entry *); | |
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; | |
61 | struct task_struct *tsk; | |
62 | ||
63 | /* Let go of any associated process */ | |
64 | tsk = PROC_I(inode)->task; | |
65 | if (tsk) | |
66 | put_task_struct(tsk); | |
67 | ||
68 | /* Let go of any associated proc directory entry */ | |
69 | de = PROC_I(inode)->pde; | |
70 | if (de) { | |
71 | if (de->owner) | |
72 | module_put(de->owner); | |
73 | de_put(de); | |
74 | } | |
75 | clear_inode(inode); | |
76 | } | |
77 | ||
78 | struct vfsmount *proc_mnt; | |
79 | ||
80 | static void proc_read_inode(struct inode * inode) | |
81 | { | |
82 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
83 | } | |
84 | ||
85 | static kmem_cache_t * proc_inode_cachep; | |
86 | ||
87 | static struct inode *proc_alloc_inode(struct super_block *sb) | |
88 | { | |
89 | struct proc_inode *ei; | |
90 | struct inode *inode; | |
91 | ||
92 | ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, SLAB_KERNEL); | |
93 | if (!ei) | |
94 | return NULL; | |
95 | ei->task = NULL; | |
96 | ei->type = 0; | |
97 | ei->op.proc_get_link = NULL; | |
98 | ei->pde = NULL; | |
99 | inode = &ei->vfs_inode; | |
100 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
101 | return inode; | |
102 | } | |
103 | ||
104 | static void proc_destroy_inode(struct inode *inode) | |
105 | { | |
106 | kmem_cache_free(proc_inode_cachep, PROC_I(inode)); | |
107 | } | |
108 | ||
109 | static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) | |
110 | { | |
111 | struct proc_inode *ei = (struct proc_inode *) foo; | |
112 | ||
113 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
114 | SLAB_CTOR_CONSTRUCTOR) | |
115 | inode_init_once(&ei->vfs_inode); | |
116 | } | |
117 | ||
118 | int __init proc_init_inodecache(void) | |
119 | { | |
120 | proc_inode_cachep = kmem_cache_create("proc_inode_cache", | |
121 | sizeof(struct proc_inode), | |
122 | 0, SLAB_RECLAIM_ACCOUNT, | |
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 | ||
157 | inode = iget(sb, ino); | |
158 | if (!inode) | |
159 | goto out_fail; | |
160 | ||
161 | PROC_I(inode)->pde = de; | |
162 | if (de) { | |
163 | if (de->mode) { | |
164 | inode->i_mode = de->mode; | |
165 | inode->i_uid = de->uid; | |
166 | inode->i_gid = de->gid; | |
167 | } | |
168 | if (de->size) | |
169 | inode->i_size = de->size; | |
170 | if (de->nlink) | |
171 | inode->i_nlink = de->nlink; | |
172 | if (!try_module_get(de->owner)) | |
173 | goto out_fail; | |
174 | if (de->proc_iops) | |
175 | inode->i_op = de->proc_iops; | |
176 | if (de->proc_fops) | |
177 | inode->i_fop = de->proc_fops; | |
178 | } | |
179 | ||
180 | out: | |
181 | return inode; | |
182 | ||
183 | out_fail: | |
184 | de_put(de); | |
185 | goto out; | |
186 | } | |
187 | ||
188 | int proc_fill_super(struct super_block *s, void *data, int silent) | |
189 | { | |
190 | struct inode * root_inode; | |
191 | ||
192 | s->s_flags |= MS_NODIRATIME; | |
193 | s->s_blocksize = 1024; | |
194 | s->s_blocksize_bits = 10; | |
195 | s->s_magic = PROC_SUPER_MAGIC; | |
196 | s->s_op = &proc_sops; | |
197 | s->s_time_gran = 1; | |
198 | ||
199 | root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root); | |
200 | if (!root_inode) | |
201 | goto out_no_root; | |
202 | /* | |
203 | * Fixup the root inode's nlink value | |
204 | */ | |
205 | root_inode->i_nlink += nr_processes(); | |
206 | root_inode->i_uid = 0; | |
207 | root_inode->i_gid = 0; | |
208 | s->s_root = d_alloc_root(root_inode); | |
209 | if (!s->s_root) | |
210 | goto out_no_root; | |
211 | return 0; | |
212 | ||
213 | out_no_root: | |
214 | printk("proc_read_super: get root inode failed\n"); | |
215 | iput(root_inode); | |
216 | return -ENOMEM; | |
217 | } | |
218 | MODULE_LICENSE("GPL"); |