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-rw-r--r--fs/debugfs/Makefile4
-rw-r--r--fs/debugfs/file.c262
-rw-r--r--fs/debugfs/inode.c328
3 files changed, 594 insertions, 0 deletions
diff --git a/fs/debugfs/Makefile b/fs/debugfs/Makefile
new file mode 100644
index 000000000000..840c45696668
--- /dev/null
+++ b/fs/debugfs/Makefile
@@ -0,0 +1,4 @@
1debugfs-objs := inode.o file.o
2
3obj-$(CONFIG_DEBUG_FS) += debugfs.o
4
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
new file mode 100644
index 000000000000..548556ff2506
--- /dev/null
+++ b/fs/debugfs/file.c
@@ -0,0 +1,262 @@
1/*
2 * file.c - part of debugfs, a tiny little debug file system
3 *
4 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2004 IBM Inc.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * debugfs is for people to use instead of /proc or /sys.
12 * See Documentation/DocBook/kernel-api for more details.
13 *
14 */
15
16#include <linux/config.h>
17#include <linux/module.h>
18#include <linux/fs.h>
19#include <linux/pagemap.h>
20#include <linux/debugfs.h>
21
22static ssize_t default_read_file(struct file *file, char __user *buf,
23 size_t count, loff_t *ppos)
24{
25 return 0;
26}
27
28static ssize_t default_write_file(struct file *file, const char __user *buf,
29 size_t count, loff_t *ppos)
30{
31 return count;
32}
33
34static int default_open(struct inode *inode, struct file *file)
35{
36 if (inode->u.generic_ip)
37 file->private_data = inode->u.generic_ip;
38
39 return 0;
40}
41
42struct file_operations debugfs_file_operations = {
43 .read = default_read_file,
44 .write = default_write_file,
45 .open = default_open,
46};
47
48#define simple_type(type, format, temptype, strtolfn) \
49static ssize_t read_file_##type(struct file *file, char __user *user_buf, \
50 size_t count, loff_t *ppos) \
51{ \
52 char buf[32]; \
53 type *val = file->private_data; \
54 \
55 snprintf(buf, sizeof(buf), format "\n", *val); \
56 return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));\
57} \
58static ssize_t write_file_##type(struct file *file, const char __user *user_buf,\
59 size_t count, loff_t *ppos) \
60{ \
61 char *endp; \
62 char buf[32]; \
63 int buf_size; \
64 type *val = file->private_data; \
65 temptype tmp; \
66 \
67 memset(buf, 0x00, sizeof(buf)); \
68 buf_size = min(count, (sizeof(buf)-1)); \
69 if (copy_from_user(buf, user_buf, buf_size)) \
70 return -EFAULT; \
71 \
72 tmp = strtolfn(buf, &endp, 0); \
73 if ((endp == buf) || ((type)tmp != tmp)) \
74 return -EINVAL; \
75 *val = tmp; \
76 return count; \
77} \
78static struct file_operations fops_##type = { \
79 .read = read_file_##type, \
80 .write = write_file_##type, \
81 .open = default_open, \
82};
83simple_type(u8, "%c", unsigned long, simple_strtoul);
84simple_type(u16, "%hi", unsigned long, simple_strtoul);
85simple_type(u32, "%i", unsigned long, simple_strtoul);
86
87/**
88 * debugfs_create_u8 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value.
89 *
90 * @name: a pointer to a string containing the name of the file to create.
91 * @mode: the permission that the file should have
92 * @parent: a pointer to the parent dentry for this file. This should be a
93 * directory dentry if set. If this paramater is NULL, then the
94 * file will be created in the root of the debugfs filesystem.
95 * @value: a pointer to the variable that the file should read to and write
96 * from.
97 *
98 * This function creates a file in debugfs with the given name that
99 * contains the value of the variable @value. If the @mode variable is so
100 * set, it can be read from, and written to.
101 *
102 * This function will return a pointer to a dentry if it succeeds. This
103 * pointer must be passed to the debugfs_remove() function when the file is
104 * to be removed (no automatic cleanup happens if your module is unloaded,
105 * you are responsible here.) If an error occurs, NULL will be returned.
106 *
107 * If debugfs is not enabled in the kernel, the value -ENODEV will be
108 * returned. It is not wise to check for this value, but rather, check for
109 * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
110 * code.
111 */
112struct dentry *debugfs_create_u8(const char *name, mode_t mode,
113 struct dentry *parent, u8 *value)
114{
115 return debugfs_create_file(name, mode, parent, value, &fops_u8);
116}
117EXPORT_SYMBOL_GPL(debugfs_create_u8);
118
119/**
120 * debugfs_create_u16 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value.
121 *
122 * @name: a pointer to a string containing the name of the file to create.
123 * @mode: the permission that the file should have
124 * @parent: a pointer to the parent dentry for this file. This should be a
125 * directory dentry if set. If this paramater is NULL, then the
126 * file will be created in the root of the debugfs filesystem.
127 * @value: a pointer to the variable that the file should read to and write
128 * from.
129 *
130 * This function creates a file in debugfs with the given name that
131 * contains the value of the variable @value. If the @mode variable is so
132 * set, it can be read from, and written to.
133 *
134 * This function will return a pointer to a dentry if it succeeds. This
135 * pointer must be passed to the debugfs_remove() function when the file is
136 * to be removed (no automatic cleanup happens if your module is unloaded,
137 * you are responsible here.) If an error occurs, NULL will be returned.
138 *
139 * If debugfs is not enabled in the kernel, the value -ENODEV will be
140 * returned. It is not wise to check for this value, but rather, check for
141 * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
142 * code.
143 */
144struct dentry *debugfs_create_u16(const char *name, mode_t mode,
145 struct dentry *parent, u16 *value)
146{
147 return debugfs_create_file(name, mode, parent, value, &fops_u16);
148}
149EXPORT_SYMBOL_GPL(debugfs_create_u16);
150
151/**
152 * debugfs_create_u32 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value.
153 *
154 * @name: a pointer to a string containing the name of the file to create.
155 * @mode: the permission that the file should have
156 * @parent: a pointer to the parent dentry for this file. This should be a
157 * directory dentry if set. If this paramater is NULL, then the
158 * file will be created in the root of the debugfs filesystem.
159 * @value: a pointer to the variable that the file should read to and write
160 * from.
161 *
162 * This function creates a file in debugfs with the given name that
163 * contains the value of the variable @value. If the @mode variable is so
164 * set, it can be read from, and written to.
165 *
166 * This function will return a pointer to a dentry if it succeeds. This
167 * pointer must be passed to the debugfs_remove() function when the file is
168 * to be removed (no automatic cleanup happens if your module is unloaded,
169 * you are responsible here.) If an error occurs, NULL will be returned.
170 *
171 * If debugfs is not enabled in the kernel, the value -ENODEV will be
172 * returned. It is not wise to check for this value, but rather, check for
173 * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
174 * code.
175 */
176struct dentry *debugfs_create_u32(const char *name, mode_t mode,
177 struct dentry *parent, u32 *value)
178{
179 return debugfs_create_file(name, mode, parent, value, &fops_u32);
180}
181EXPORT_SYMBOL_GPL(debugfs_create_u32);
182
183static ssize_t read_file_bool(struct file *file, char __user *user_buf,
184 size_t count, loff_t *ppos)
185{
186 char buf[3];
187 u32 *val = file->private_data;
188
189 if (*val)
190 buf[0] = 'Y';
191 else
192 buf[0] = 'N';
193 buf[1] = '\n';
194 buf[2] = 0x00;
195 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
196}
197
198static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
199 size_t count, loff_t *ppos)
200{
201 char buf[32];
202 int buf_size;
203 u32 *val = file->private_data;
204
205 buf_size = min(count, (sizeof(buf)-1));
206 if (copy_from_user(buf, user_buf, buf_size))
207 return -EFAULT;
208
209 switch (buf[0]) {
210 case 'y':
211 case 'Y':
212 case '1':
213 *val = 1;
214 break;
215 case 'n':
216 case 'N':
217 case '0':
218 *val = 0;
219 break;
220 }
221
222 return count;
223}
224
225static struct file_operations fops_bool = {
226 .read = read_file_bool,
227 .write = write_file_bool,
228 .open = default_open,
229};
230
231/**
232 * debugfs_create_bool - create a file in the debugfs filesystem that is used to read and write a boolean value.
233 *
234 * @name: a pointer to a string containing the name of the file to create.
235 * @mode: the permission that the file should have
236 * @parent: a pointer to the parent dentry for this file. This should be a
237 * directory dentry if set. If this paramater is NULL, then the
238 * file will be created in the root of the debugfs filesystem.
239 * @value: a pointer to the variable that the file should read to and write
240 * from.
241 *
242 * This function creates a file in debugfs with the given name that
243 * contains the value of the variable @value. If the @mode variable is so
244 * set, it can be read from, and written to.
245 *
246 * This function will return a pointer to a dentry if it succeeds. This
247 * pointer must be passed to the debugfs_remove() function when the file is
248 * to be removed (no automatic cleanup happens if your module is unloaded,
249 * you are responsible here.) If an error occurs, NULL will be returned.
250 *
251 * If debugfs is not enabled in the kernel, the value -ENODEV will be
252 * returned. It is not wise to check for this value, but rather, check for
253 * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
254 * code.
255 */
256struct dentry *debugfs_create_bool(const char *name, mode_t mode,
257 struct dentry *parent, u32 *value)
258{
259 return debugfs_create_file(name, mode, parent, value, &fops_bool);
260}
261EXPORT_SYMBOL_GPL(debugfs_create_bool);
262
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
new file mode 100644
index 000000000000..b529786699e7
--- /dev/null
+++ b/fs/debugfs/inode.c
@@ -0,0 +1,328 @@
1/*
2 * file.c - part of debugfs, a tiny little debug file system
3 *
4 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2004 IBM Inc.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * debugfs is for people to use instead of /proc or /sys.
12 * See Documentation/DocBook/kernel-api for more details.
13 *
14 */
15
16/* uncomment to get debug messages from the debug filesystem, ah the irony. */
17/* #define DEBUG */
18
19#include <linux/config.h>
20#include <linux/module.h>
21#include <linux/fs.h>
22#include <linux/mount.h>
23#include <linux/pagemap.h>
24#include <linux/init.h>
25#include <linux/namei.h>
26#include <linux/debugfs.h>
27
28#define DEBUGFS_MAGIC 0x64626720
29
30/* declared over in file.c */
31extern struct file_operations debugfs_file_operations;
32
33static struct vfsmount *debugfs_mount;
34static int debugfs_mount_count;
35
36static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t dev)
37{
38 struct inode *inode = new_inode(sb);
39
40 if (inode) {
41 inode->i_mode = mode;
42 inode->i_uid = 0;
43 inode->i_gid = 0;
44 inode->i_blksize = PAGE_CACHE_SIZE;
45 inode->i_blocks = 0;
46 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
47 switch (mode & S_IFMT) {
48 default:
49 init_special_inode(inode, mode, dev);
50 break;
51 case S_IFREG:
52 inode->i_fop = &debugfs_file_operations;
53 break;
54 case S_IFDIR:
55 inode->i_op = &simple_dir_inode_operations;
56 inode->i_fop = &simple_dir_operations;
57
58 /* directory inodes start off with i_nlink == 2 (for "." entry) */
59 inode->i_nlink++;
60 break;
61 }
62 }
63 return inode;
64}
65
66/* SMP-safe */
67static int debugfs_mknod(struct inode *dir, struct dentry *dentry,
68 int mode, dev_t dev)
69{
70 struct inode *inode = debugfs_get_inode(dir->i_sb, mode, dev);
71 int error = -EPERM;
72
73 if (dentry->d_inode)
74 return -EEXIST;
75
76 if (inode) {
77 d_instantiate(dentry, inode);
78 dget(dentry);
79 error = 0;
80 }
81 return error;
82}
83
84static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
85{
86 int res;
87
88 mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
89 res = debugfs_mknod(dir, dentry, mode, 0);
90 if (!res)
91 dir->i_nlink++;
92 return res;
93}
94
95static int debugfs_create(struct inode *dir, struct dentry *dentry, int mode)
96{
97 mode = (mode & S_IALLUGO) | S_IFREG;
98 return debugfs_mknod(dir, dentry, mode, 0);
99}
100
101static inline int debugfs_positive(struct dentry *dentry)
102{
103 return dentry->d_inode && !d_unhashed(dentry);
104}
105
106static int debug_fill_super(struct super_block *sb, void *data, int silent)
107{
108 static struct tree_descr debug_files[] = {{""}};
109
110 return simple_fill_super(sb, DEBUGFS_MAGIC, debug_files);
111}
112
113static struct dentry * get_dentry(struct dentry *parent, const char *name)
114{
115 struct qstr qstr;
116
117 qstr.name = name;
118 qstr.len = strlen(name);
119 qstr.hash = full_name_hash(name,qstr.len);
120 return lookup_hash(&qstr,parent);
121}
122
123static struct super_block *debug_get_sb(struct file_system_type *fs_type,
124 int flags, const char *dev_name,
125 void *data)
126{
127 return get_sb_single(fs_type, flags, data, debug_fill_super);
128}
129
130static struct file_system_type debug_fs_type = {
131 .owner = THIS_MODULE,
132 .name = "debugfs",
133 .get_sb = debug_get_sb,
134 .kill_sb = kill_litter_super,
135};
136
137static int debugfs_create_by_name(const char *name, mode_t mode,
138 struct dentry *parent,
139 struct dentry **dentry)
140{
141 int error = 0;
142
143 /* If the parent is not specified, we create it in the root.
144 * We need the root dentry to do this, which is in the super
145 * block. A pointer to that is in the struct vfsmount that we
146 * have around.
147 */
148 if (!parent ) {
149 if (debugfs_mount && debugfs_mount->mnt_sb) {
150 parent = debugfs_mount->mnt_sb->s_root;
151 }
152 }
153 if (!parent) {
154 pr_debug("debugfs: Ah! can not find a parent!\n");
155 return -EFAULT;
156 }
157
158 *dentry = NULL;
159 down(&parent->d_inode->i_sem);
160 *dentry = get_dentry (parent, name);
161 if (!IS_ERR(dentry)) {
162 if ((mode & S_IFMT) == S_IFDIR)
163 error = debugfs_mkdir(parent->d_inode, *dentry, mode);
164 else
165 error = debugfs_create(parent->d_inode, *dentry, mode);
166 } else
167 error = PTR_ERR(dentry);
168 up(&parent->d_inode->i_sem);
169
170 return error;
171}
172
173/**
174 * debugfs_create_file - create a file in the debugfs filesystem
175 *
176 * @name: a pointer to a string containing the name of the file to create.
177 * @mode: the permission that the file should have
178 * @parent: a pointer to the parent dentry for this file. This should be a
179 * directory dentry if set. If this paramater is NULL, then the
180 * file will be created in the root of the debugfs filesystem.
181 * @data: a pointer to something that the caller will want to get to later
182 * on. The inode.u.generic_ip pointer will point to this value on
183 * the open() call.
184 * @fops: a pointer to a struct file_operations that should be used for
185 * this file.
186 *
187 * This is the basic "create a file" function for debugfs. It allows for a
188 * wide range of flexibility in createing a file, or a directory (if you
189 * want to create a directory, the debugfs_create_dir() function is
190 * recommended to be used instead.)
191 *
192 * This function will return a pointer to a dentry if it succeeds. This
193 * pointer must be passed to the debugfs_remove() function when the file is
194 * to be removed (no automatic cleanup happens if your module is unloaded,
195 * you are responsible here.) If an error occurs, NULL will be returned.
196 *
197 * If debugfs is not enabled in the kernel, the value -ENODEV will be
198 * returned. It is not wise to check for this value, but rather, check for
199 * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
200 * code.
201 */
202struct dentry *debugfs_create_file(const char *name, mode_t mode,
203 struct dentry *parent, void *data,
204 struct file_operations *fops)
205{
206 struct dentry *dentry = NULL;
207 int error;
208
209 pr_debug("debugfs: creating file '%s'\n",name);
210
211 error = simple_pin_fs("debugfs", &debugfs_mount, &debugfs_mount_count);
212 if (error)
213 goto exit;
214
215 error = debugfs_create_by_name(name, mode, parent, &dentry);
216 if (error) {
217 dentry = NULL;
218 goto exit;
219 }
220
221 if (dentry->d_inode) {
222 if (data)
223 dentry->d_inode->u.generic_ip = data;
224 if (fops)
225 dentry->d_inode->i_fop = fops;
226 }
227exit:
228 return dentry;
229}
230EXPORT_SYMBOL_GPL(debugfs_create_file);
231
232/**
233 * debugfs_create_dir - create a directory in the debugfs filesystem
234 *
235 * @name: a pointer to a string containing the name of the directory to
236 * create.
237 * @parent: a pointer to the parent dentry for this file. This should be a
238 * directory dentry if set. If this paramater is NULL, then the
239 * directory will be created in the root of the debugfs filesystem.
240 *
241 * This function creates a directory in debugfs with the given name.
242 *
243 * This function will return a pointer to a dentry if it succeeds. This
244 * pointer must be passed to the debugfs_remove() function when the file is
245 * to be removed (no automatic cleanup happens if your module is unloaded,
246 * you are responsible here.) If an error occurs, NULL will be returned.
247 *
248 * If debugfs is not enabled in the kernel, the value -ENODEV will be
249 * returned. It is not wise to check for this value, but rather, check for
250 * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
251 * code.
252 */
253struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
254{
255 return debugfs_create_file(name,
256 S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
257 parent, NULL, NULL);
258}
259EXPORT_SYMBOL_GPL(debugfs_create_dir);
260
261/**
262 * debugfs_remove - removes a file or directory from the debugfs filesystem
263 *
264 * @dentry: a pointer to a the dentry of the file or directory to be
265 * removed.
266 *
267 * This function removes a file or directory in debugfs that was previously
268 * created with a call to another debugfs function (like
269 * debufs_create_file() or variants thereof.)
270 *
271 * This function is required to be called in order for the file to be
272 * removed, no automatic cleanup of files will happen when a module is
273 * removed, you are responsible here.
274 */
275void debugfs_remove(struct dentry *dentry)
276{
277 struct dentry *parent;
278
279 if (!dentry)
280 return;
281
282 parent = dentry->d_parent;
283 if (!parent || !parent->d_inode)
284 return;
285
286 down(&parent->d_inode->i_sem);
287 if (debugfs_positive(dentry)) {
288 if (dentry->d_inode) {
289 if (S_ISDIR(dentry->d_inode->i_mode))
290 simple_rmdir(parent->d_inode, dentry);
291 else
292 simple_unlink(parent->d_inode, dentry);
293 dput(dentry);
294 }
295 }
296 up(&parent->d_inode->i_sem);
297 simple_release_fs(&debugfs_mount, &debugfs_mount_count);
298}
299EXPORT_SYMBOL_GPL(debugfs_remove);
300
301static decl_subsys(debug, NULL, NULL);
302
303static int __init debugfs_init(void)
304{
305 int retval;
306
307 kset_set_kset_s(&debug_subsys, kernel_subsys);
308 retval = subsystem_register(&debug_subsys);
309 if (retval)
310 return retval;
311
312 retval = register_filesystem(&debug_fs_type);
313 if (retval)
314 subsystem_unregister(&debug_subsys);
315 return retval;
316}
317
318static void __exit debugfs_exit(void)
319{
320 simple_release_fs(&debugfs_mount, &debugfs_mount_count);
321 unregister_filesystem(&debug_fs_type);
322 subsystem_unregister(&debug_subsys);
323}
324
325core_initcall(debugfs_init);
326module_exit(debugfs_exit);
327MODULE_LICENSE("GPL");
328
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