Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/module.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/mount.h> |
| 19 | #include <linux/pagemap.h> |
| 20 | #include <linux/init.h> |
Randy Dunlap | 4d8ebdd | 2006-11-25 11:09:26 -0800 | [diff] [blame] | 21 | #include <linux/kobject.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/namei.h> |
| 23 | #include <linux/debugfs.h> |
Mathieu Desnoyers | 4f36557 | 2006-11-24 13:45:37 -0500 | [diff] [blame] | 24 | #include <linux/fsnotify.h> |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 25 | #include <linux/string.h> |
Mimi Zohar | 9256292 | 2008-10-07 14:00:12 -0400 | [diff] [blame] | 26 | #include <linux/magic.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 27 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | static struct vfsmount *debugfs_mount; |
| 30 | static int debugfs_mount_count; |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 31 | static bool debugfs_registered; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 33 | static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t dev, |
| 34 | void *data, const struct file_operations *fops) |
| 35 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | { |
| 37 | struct inode *inode = new_inode(sb); |
| 38 | |
| 39 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 40 | inode->i_ino = get_next_ino(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | inode->i_mode = mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 43 | switch (mode & S_IFMT) { |
| 44 | default: |
| 45 | init_special_inode(inode, mode, dev); |
| 46 | break; |
| 47 | case S_IFREG: |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 48 | inode->i_fop = fops ? fops : &debugfs_file_operations; |
| 49 | inode->i_private = data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | break; |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 51 | case S_IFLNK: |
| 52 | inode->i_op = &debugfs_link_operations; |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 53 | inode->i_fop = fops; |
| 54 | inode->i_private = data; |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 55 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | case S_IFDIR: |
| 57 | inode->i_op = &simple_dir_inode_operations; |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 58 | inode->i_fop = fops ? fops : &simple_dir_operations; |
| 59 | inode->i_private = data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
Mathieu Desnoyers | bafb232 | 2006-11-24 13:46:30 -0500 | [diff] [blame] | 61 | /* directory inodes start off with i_nlink == 2 |
| 62 | * (for "." entry) */ |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 63 | inc_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | break; |
| 65 | } |
| 66 | } |
| 67 | return inode; |
| 68 | } |
| 69 | |
| 70 | /* SMP-safe */ |
| 71 | static int debugfs_mknod(struct inode *dir, struct dentry *dentry, |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 72 | int mode, dev_t dev, void *data, |
| 73 | const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | { |
Jens Axboe | 71601e2 | 2006-06-08 10:26:39 +0200 | [diff] [blame] | 75 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | int error = -EPERM; |
| 77 | |
| 78 | if (dentry->d_inode) |
| 79 | return -EEXIST; |
| 80 | |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 81 | inode = debugfs_get_inode(dir->i_sb, mode, dev, data, fops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | if (inode) { |
| 83 | d_instantiate(dentry, inode); |
| 84 | dget(dentry); |
| 85 | error = 0; |
| 86 | } |
| 87 | return error; |
| 88 | } |
| 89 | |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 90 | static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, int mode, |
| 91 | void *data, const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | { |
| 93 | int res; |
| 94 | |
| 95 | mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR; |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 96 | res = debugfs_mknod(dir, dentry, mode, 0, data, fops); |
Mathieu Desnoyers | 4f36557 | 2006-11-24 13:45:37 -0500 | [diff] [blame] | 97 | if (!res) { |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 98 | inc_nlink(dir); |
Mathieu Desnoyers | 4f36557 | 2006-11-24 13:45:37 -0500 | [diff] [blame] | 99 | fsnotify_mkdir(dir, dentry); |
| 100 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | return res; |
| 102 | } |
| 103 | |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 104 | static int debugfs_link(struct inode *dir, struct dentry *dentry, int mode, |
| 105 | void *data, const struct file_operations *fops) |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 106 | { |
| 107 | mode = (mode & S_IALLUGO) | S_IFLNK; |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 108 | return debugfs_mknod(dir, dentry, mode, 0, data, fops); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 109 | } |
| 110 | |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 111 | static int debugfs_create(struct inode *dir, struct dentry *dentry, int mode, |
| 112 | void *data, const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | { |
Mathieu Desnoyers | 4f36557 | 2006-11-24 13:45:37 -0500 | [diff] [blame] | 114 | int res; |
| 115 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | mode = (mode & S_IALLUGO) | S_IFREG; |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 117 | res = debugfs_mknod(dir, dentry, mode, 0, data, fops); |
Mathieu Desnoyers | 4f36557 | 2006-11-24 13:45:37 -0500 | [diff] [blame] | 118 | if (!res) |
| 119 | fsnotify_create(dir, dentry); |
| 120 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | } |
| 122 | |
| 123 | static inline int debugfs_positive(struct dentry *dentry) |
| 124 | { |
| 125 | return dentry->d_inode && !d_unhashed(dentry); |
| 126 | } |
| 127 | |
| 128 | static int debug_fill_super(struct super_block *sb, void *data, int silent) |
| 129 | { |
| 130 | static struct tree_descr debug_files[] = {{""}}; |
| 131 | |
| 132 | return simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); |
| 133 | } |
| 134 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 135 | static struct dentry *debug_mount(struct file_system_type *fs_type, |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 136 | int flags, const char *dev_name, |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 137 | void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | { |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 139 | return mount_single(fs_type, flags, data, debug_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | } |
| 141 | |
| 142 | static struct file_system_type debug_fs_type = { |
| 143 | .owner = THIS_MODULE, |
| 144 | .name = "debugfs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 145 | .mount = debug_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | .kill_sb = kill_litter_super, |
| 147 | }; |
| 148 | |
| 149 | static int debugfs_create_by_name(const char *name, mode_t mode, |
| 150 | struct dentry *parent, |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 151 | struct dentry **dentry, |
| 152 | void *data, |
| 153 | const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | { |
| 155 | int error = 0; |
| 156 | |
| 157 | /* If the parent is not specified, we create it in the root. |
| 158 | * We need the root dentry to do this, which is in the super |
| 159 | * block. A pointer to that is in the struct vfsmount that we |
| 160 | * have around. |
| 161 | */ |
Al Viro | ef52c75 | 2010-01-25 04:50:43 -0500 | [diff] [blame] | 162 | if (!parent) |
| 163 | parent = debugfs_mount->mnt_sb->s_root; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | |
| 165 | *dentry = NULL; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 166 | mutex_lock(&parent->d_inode->i_mutex); |
Christoph Hellwig | 5f45f1a | 2005-06-23 00:09:12 -0700 | [diff] [blame] | 167 | *dentry = lookup_one_len(name, parent, strlen(name)); |
Akinobu Mita | 7bb0386 | 2006-10-19 12:24:42 +0900 | [diff] [blame] | 168 | if (!IS_ERR(*dentry)) { |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 169 | switch (mode & S_IFMT) { |
| 170 | case S_IFDIR: |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 171 | error = debugfs_mkdir(parent->d_inode, *dentry, mode, |
| 172 | data, fops); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 173 | break; |
| 174 | case S_IFLNK: |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 175 | error = debugfs_link(parent->d_inode, *dentry, mode, |
| 176 | data, fops); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 177 | break; |
| 178 | default: |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 179 | error = debugfs_create(parent->d_inode, *dentry, mode, |
| 180 | data, fops); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 181 | break; |
| 182 | } |
Mathieu Desnoyers | 65c3333 | 2006-11-24 13:50:09 -0500 | [diff] [blame] | 183 | dput(*dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | } else |
Akinobu Mita | 7bb0386 | 2006-10-19 12:24:42 +0900 | [diff] [blame] | 185 | error = PTR_ERR(*dentry); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 186 | mutex_unlock(&parent->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | |
| 188 | return error; |
| 189 | } |
| 190 | |
| 191 | /** |
| 192 | * debugfs_create_file - create a file in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | * @name: a pointer to a string containing the name of the file to create. |
Alberto Bertogli | be030e6 | 2009-10-31 18:26:52 -0300 | [diff] [blame] | 194 | * @mode: the permission that the file should have. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 196 | * directory dentry if set. If this paramater is NULL, then the |
| 197 | * file will be created in the root of the debugfs filesystem. |
| 198 | * @data: a pointer to something that the caller will want to get to later |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 199 | * on. The inode.i_private pointer will point to this value on |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | * the open() call. |
| 201 | * @fops: a pointer to a struct file_operations that should be used for |
| 202 | * this file. |
| 203 | * |
| 204 | * This is the basic "create a file" function for debugfs. It allows for a |
Alberto Bertogli | be030e6 | 2009-10-31 18:26:52 -0300 | [diff] [blame] | 205 | * wide range of flexibility in creating a file, or a directory (if you want |
| 206 | * to create a directory, the debugfs_create_dir() function is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | * recommended to be used instead.) |
| 208 | * |
| 209 | * This function will return a pointer to a dentry if it succeeds. This |
| 210 | * pointer must be passed to the debugfs_remove() function when the file is |
| 211 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 212 | * you are responsible here.) If an error occurs, %NULL will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 214 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
Cornelia Huck | 873760f | 2007-02-14 07:57:47 +0100 | [diff] [blame] | 215 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | */ |
| 217 | struct dentry *debugfs_create_file(const char *name, mode_t mode, |
| 218 | struct dentry *parent, void *data, |
Arjan van de Ven | 99ac48f | 2006-03-28 01:56:41 -0800 | [diff] [blame] | 219 | const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | { |
| 221 | struct dentry *dentry = NULL; |
| 222 | int error; |
| 223 | |
| 224 | pr_debug("debugfs: creating file '%s'\n",name); |
| 225 | |
Mathieu Desnoyers | 63223a0 | 2006-11-24 13:48:19 -0500 | [diff] [blame] | 226 | error = simple_pin_fs(&debug_fs_type, &debugfs_mount, |
| 227 | &debugfs_mount_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | if (error) |
| 229 | goto exit; |
| 230 | |
Mathieu Desnoyers | d3a3b0a | 2009-11-17 14:40:26 -0800 | [diff] [blame] | 231 | error = debugfs_create_by_name(name, mode, parent, &dentry, |
| 232 | data, fops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | if (error) { |
| 234 | dentry = NULL; |
Mathieu Desnoyers | 63223a0 | 2006-11-24 13:48:19 -0500 | [diff] [blame] | 235 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | goto exit; |
| 237 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | exit: |
| 239 | return dentry; |
| 240 | } |
| 241 | EXPORT_SYMBOL_GPL(debugfs_create_file); |
| 242 | |
| 243 | /** |
| 244 | * debugfs_create_dir - create a directory in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | * @name: a pointer to a string containing the name of the directory to |
| 246 | * create. |
| 247 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 248 | * directory dentry if set. If this paramater is NULL, then the |
| 249 | * directory will be created in the root of the debugfs filesystem. |
| 250 | * |
| 251 | * This function creates a directory in debugfs with the given name. |
| 252 | * |
| 253 | * This function will return a pointer to a dentry if it succeeds. This |
| 254 | * pointer must be passed to the debugfs_remove() function when the file is |
| 255 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 256 | * you are responsible here.) If an error occurs, %NULL will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 258 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
Cornelia Huck | 873760f | 2007-02-14 07:57:47 +0100 | [diff] [blame] | 259 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | */ |
| 261 | struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) |
| 262 | { |
| 263 | return debugfs_create_file(name, |
| 264 | S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
| 265 | parent, NULL, NULL); |
| 266 | } |
| 267 | EXPORT_SYMBOL_GPL(debugfs_create_dir); |
| 268 | |
| 269 | /** |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 270 | * debugfs_create_symlink- create a symbolic link in the debugfs filesystem |
| 271 | * @name: a pointer to a string containing the name of the symbolic link to |
| 272 | * create. |
| 273 | * @parent: a pointer to the parent dentry for this symbolic link. This |
| 274 | * should be a directory dentry if set. If this paramater is NULL, |
| 275 | * then the symbolic link will be created in the root of the debugfs |
| 276 | * filesystem. |
| 277 | * @target: a pointer to a string containing the path to the target of the |
| 278 | * symbolic link. |
| 279 | * |
| 280 | * This function creates a symbolic link with the given name in debugfs that |
| 281 | * links to the given target path. |
| 282 | * |
| 283 | * This function will return a pointer to a dentry if it succeeds. This |
| 284 | * pointer must be passed to the debugfs_remove() function when the symbolic |
| 285 | * link is to be removed (no automatic cleanup happens if your module is |
| 286 | * unloaded, you are responsible here.) If an error occurs, %NULL will be |
| 287 | * returned. |
| 288 | * |
| 289 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
Cornelia Huck | 873760f | 2007-02-14 07:57:47 +0100 | [diff] [blame] | 290 | * returned. |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 291 | */ |
| 292 | struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, |
| 293 | const char *target) |
| 294 | { |
| 295 | struct dentry *result; |
| 296 | char *link; |
| 297 | |
| 298 | link = kstrdup(target, GFP_KERNEL); |
| 299 | if (!link) |
| 300 | return NULL; |
| 301 | |
| 302 | result = debugfs_create_file(name, S_IFLNK | S_IRWXUGO, parent, link, |
| 303 | NULL); |
| 304 | if (!result) |
| 305 | kfree(link); |
| 306 | return result; |
| 307 | } |
| 308 | EXPORT_SYMBOL_GPL(debugfs_create_symlink); |
| 309 | |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 310 | static int __debugfs_remove(struct dentry *dentry, struct dentry *parent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | { |
Mathieu Desnoyers | 65c3333 | 2006-11-24 13:50:09 -0500 | [diff] [blame] | 312 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | if (debugfs_positive(dentry)) { |
| 315 | if (dentry->d_inode) { |
Mathieu Desnoyers | 29a7f3a | 2006-11-24 13:51:14 -0500 | [diff] [blame] | 316 | dget(dentry); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 317 | switch (dentry->d_inode->i_mode & S_IFMT) { |
| 318 | case S_IFDIR: |
Mathieu Desnoyers | 65c3333 | 2006-11-24 13:50:09 -0500 | [diff] [blame] | 319 | ret = simple_rmdir(parent->d_inode, dentry); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 320 | break; |
| 321 | case S_IFLNK: |
| 322 | kfree(dentry->d_inode->i_private); |
| 323 | /* fall through */ |
| 324 | default: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | simple_unlink(parent->d_inode, dentry); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 326 | break; |
| 327 | } |
Mathieu Desnoyers | 29a7f3a | 2006-11-24 13:51:14 -0500 | [diff] [blame] | 328 | if (!ret) |
| 329 | d_delete(dentry); |
| 330 | dput(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | } |
| 332 | } |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 333 | return ret; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 334 | } |
| 335 | |
| 336 | /** |
| 337 | * debugfs_remove - removes a file or directory from the debugfs filesystem |
| 338 | * @dentry: a pointer to a the dentry of the file or directory to be |
| 339 | * removed. |
| 340 | * |
| 341 | * This function removes a file or directory in debugfs that was previously |
| 342 | * created with a call to another debugfs function (like |
| 343 | * debugfs_create_file() or variants thereof.) |
| 344 | * |
| 345 | * This function is required to be called in order for the file to be |
| 346 | * removed, no automatic cleanup of files will happen when a module is |
| 347 | * removed, you are responsible here. |
| 348 | */ |
| 349 | void debugfs_remove(struct dentry *dentry) |
| 350 | { |
| 351 | struct dentry *parent; |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 352 | int ret; |
| 353 | |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 354 | if (!dentry) |
| 355 | return; |
| 356 | |
| 357 | parent = dentry->d_parent; |
| 358 | if (!parent || !parent->d_inode) |
| 359 | return; |
| 360 | |
| 361 | mutex_lock(&parent->d_inode->i_mutex); |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 362 | ret = __debugfs_remove(dentry, parent); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 363 | mutex_unlock(&parent->d_inode->i_mutex); |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 364 | if (!ret) |
| 365 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | } |
| 367 | EXPORT_SYMBOL_GPL(debugfs_remove); |
| 368 | |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 369 | /** |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 370 | * debugfs_remove_recursive - recursively removes a directory |
| 371 | * @dentry: a pointer to a the dentry of the directory to be removed. |
| 372 | * |
| 373 | * This function recursively removes a directory tree in debugfs that |
| 374 | * was previously created with a call to another debugfs function |
| 375 | * (like debugfs_create_file() or variants thereof.) |
| 376 | * |
| 377 | * This function is required to be called in order for the file to be |
| 378 | * removed, no automatic cleanup of files will happen when a module is |
| 379 | * removed, you are responsible here. |
| 380 | */ |
| 381 | void debugfs_remove_recursive(struct dentry *dentry) |
| 382 | { |
| 383 | struct dentry *child; |
| 384 | struct dentry *parent; |
| 385 | |
| 386 | if (!dentry) |
| 387 | return; |
| 388 | |
| 389 | parent = dentry->d_parent; |
| 390 | if (!parent || !parent->d_inode) |
| 391 | return; |
| 392 | |
| 393 | parent = dentry; |
| 394 | mutex_lock(&parent->d_inode->i_mutex); |
| 395 | |
| 396 | while (1) { |
| 397 | /* |
| 398 | * When all dentries under "parent" has been removed, |
| 399 | * walk up the tree until we reach our starting point. |
| 400 | */ |
| 401 | if (list_empty(&parent->d_subdirs)) { |
| 402 | mutex_unlock(&parent->d_inode->i_mutex); |
| 403 | if (parent == dentry) |
| 404 | break; |
| 405 | parent = parent->d_parent; |
| 406 | mutex_lock(&parent->d_inode->i_mutex); |
| 407 | } |
| 408 | child = list_entry(parent->d_subdirs.next, struct dentry, |
| 409 | d_u.d_child); |
Steven Rostedt | 56a83cc | 2009-04-25 00:39:40 -0400 | [diff] [blame] | 410 | next_sibling: |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 411 | |
| 412 | /* |
| 413 | * If "child" isn't empty, walk down the tree and |
| 414 | * remove all its descendants first. |
| 415 | */ |
| 416 | if (!list_empty(&child->d_subdirs)) { |
| 417 | mutex_unlock(&parent->d_inode->i_mutex); |
| 418 | parent = child; |
| 419 | mutex_lock(&parent->d_inode->i_mutex); |
| 420 | continue; |
| 421 | } |
| 422 | __debugfs_remove(child, parent); |
| 423 | if (parent->d_subdirs.next == &child->d_u.d_child) { |
| 424 | /* |
Steven Rostedt | 56a83cc | 2009-04-25 00:39:40 -0400 | [diff] [blame] | 425 | * Try the next sibling. |
| 426 | */ |
| 427 | if (child->d_u.d_child.next != &parent->d_subdirs) { |
| 428 | child = list_entry(child->d_u.d_child.next, |
| 429 | struct dentry, |
| 430 | d_u.d_child); |
| 431 | goto next_sibling; |
| 432 | } |
| 433 | |
| 434 | /* |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 435 | * Avoid infinite loop if we fail to remove |
| 436 | * one dentry. |
| 437 | */ |
| 438 | mutex_unlock(&parent->d_inode->i_mutex); |
| 439 | break; |
| 440 | } |
| 441 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
| 442 | } |
| 443 | |
| 444 | parent = dentry->d_parent; |
| 445 | mutex_lock(&parent->d_inode->i_mutex); |
| 446 | __debugfs_remove(dentry, parent); |
| 447 | mutex_unlock(&parent->d_inode->i_mutex); |
| 448 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
| 449 | } |
| 450 | EXPORT_SYMBOL_GPL(debugfs_remove_recursive); |
| 451 | |
| 452 | /** |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 453 | * debugfs_rename - rename a file/directory in the debugfs filesystem |
| 454 | * @old_dir: a pointer to the parent dentry for the renamed object. This |
| 455 | * should be a directory dentry. |
| 456 | * @old_dentry: dentry of an object to be renamed. |
| 457 | * @new_dir: a pointer to the parent dentry where the object should be |
| 458 | * moved. This should be a directory dentry. |
| 459 | * @new_name: a pointer to a string containing the target name. |
| 460 | * |
| 461 | * This function renames a file/directory in debugfs. The target must not |
| 462 | * exist for rename to succeed. |
| 463 | * |
| 464 | * This function will return a pointer to old_dentry (which is updated to |
| 465 | * reflect renaming) if it succeeds. If an error occurs, %NULL will be |
| 466 | * returned. |
| 467 | * |
| 468 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 469 | * returned. |
| 470 | */ |
| 471 | struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, |
| 472 | struct dentry *new_dir, const char *new_name) |
| 473 | { |
| 474 | int error; |
| 475 | struct dentry *dentry = NULL, *trap; |
| 476 | const char *old_name; |
| 477 | |
| 478 | trap = lock_rename(new_dir, old_dir); |
| 479 | /* Source or destination directories don't exist? */ |
| 480 | if (!old_dir->d_inode || !new_dir->d_inode) |
| 481 | goto exit; |
| 482 | /* Source does not exist, cyclic rename, or mountpoint? */ |
| 483 | if (!old_dentry->d_inode || old_dentry == trap || |
| 484 | d_mountpoint(old_dentry)) |
| 485 | goto exit; |
| 486 | dentry = lookup_one_len(new_name, new_dir, strlen(new_name)); |
| 487 | /* Lookup failed, cyclic rename or target exists? */ |
| 488 | if (IS_ERR(dentry) || dentry == trap || dentry->d_inode) |
| 489 | goto exit; |
| 490 | |
| 491 | old_name = fsnotify_oldname_init(old_dentry->d_name.name); |
| 492 | |
| 493 | error = simple_rename(old_dir->d_inode, old_dentry, new_dir->d_inode, |
| 494 | dentry); |
| 495 | if (error) { |
| 496 | fsnotify_oldname_free(old_name); |
| 497 | goto exit; |
| 498 | } |
| 499 | d_move(old_dentry, dentry); |
| 500 | fsnotify_move(old_dir->d_inode, new_dir->d_inode, old_name, |
Al Viro | 123df29 | 2009-12-25 04:57:57 -0500 | [diff] [blame] | 501 | S_ISDIR(old_dentry->d_inode->i_mode), |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 502 | NULL, old_dentry); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 503 | fsnotify_oldname_free(old_name); |
| 504 | unlock_rename(new_dir, old_dir); |
| 505 | dput(dentry); |
| 506 | return old_dentry; |
| 507 | exit: |
| 508 | if (dentry && !IS_ERR(dentry)) |
| 509 | dput(dentry); |
| 510 | unlock_rename(new_dir, old_dir); |
| 511 | return NULL; |
| 512 | } |
| 513 | EXPORT_SYMBOL_GPL(debugfs_rename); |
| 514 | |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 515 | /** |
| 516 | * debugfs_initialized - Tells whether debugfs has been registered |
| 517 | */ |
| 518 | bool debugfs_initialized(void) |
| 519 | { |
| 520 | return debugfs_registered; |
| 521 | } |
| 522 | EXPORT_SYMBOL_GPL(debugfs_initialized); |
| 523 | |
| 524 | |
Greg Kroah-Hartman | 191e186 | 2007-10-29 20:13:17 +0100 | [diff] [blame] | 525 | static struct kobject *debug_kobj; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | |
| 527 | static int __init debugfs_init(void) |
| 528 | { |
| 529 | int retval; |
| 530 | |
Greg Kroah-Hartman | 0ff21e4 | 2007-11-06 10:36:58 -0800 | [diff] [blame] | 531 | debug_kobj = kobject_create_and_add("debug", kernel_kobj); |
Greg Kroah-Hartman | 191e186 | 2007-10-29 20:13:17 +0100 | [diff] [blame] | 532 | if (!debug_kobj) |
| 533 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | |
| 535 | retval = register_filesystem(&debug_fs_type); |
| 536 | if (retval) |
Greg Kroah-Hartman | 197b12d | 2007-12-20 08:13:05 -0800 | [diff] [blame] | 537 | kobject_put(debug_kobj); |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 538 | else |
| 539 | debugfs_registered = true; |
| 540 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | return retval; |
| 542 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | core_initcall(debugfs_init); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | |