Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Harry Wei | bd33d12 | 2011-07-16 16:45:13 +0800 | [diff] [blame] | 2 | * inode.c - part of debugfs, a tiny little debug file system |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 26 | #include <linux/seq_file.h> |
| 27 | #include <linux/parser.h> |
Mimi Zohar | 9256292 | 2008-10-07 14:00:12 -0400 | [diff] [blame] | 28 | #include <linux/magic.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 29 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
Kees Cook | 82aceae4 | 2012-08-27 13:32:15 -0700 | [diff] [blame] | 31 | #define DEBUGFS_DEFAULT_MODE 0700 |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 32 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | static struct vfsmount *debugfs_mount; |
| 34 | static int debugfs_mount_count; |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 35 | static bool debugfs_registered; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 37 | static struct inode *debugfs_get_inode(struct super_block *sb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | { |
| 39 | struct inode *inode = new_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 41 | inode->i_ino = get_next_ino(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | } |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 44 | return inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | } |
| 46 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | static inline int debugfs_positive(struct dentry *dentry) |
| 48 | { |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 49 | return d_really_is_positive(dentry) && !d_unhashed(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | } |
| 51 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 52 | struct debugfs_mount_opts { |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 53 | kuid_t uid; |
| 54 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 55 | umode_t mode; |
| 56 | }; |
| 57 | |
| 58 | enum { |
| 59 | Opt_uid, |
| 60 | Opt_gid, |
| 61 | Opt_mode, |
| 62 | Opt_err |
| 63 | }; |
| 64 | |
| 65 | static const match_table_t tokens = { |
| 66 | {Opt_uid, "uid=%u"}, |
| 67 | {Opt_gid, "gid=%u"}, |
| 68 | {Opt_mode, "mode=%o"}, |
| 69 | {Opt_err, NULL} |
| 70 | }; |
| 71 | |
| 72 | struct debugfs_fs_info { |
| 73 | struct debugfs_mount_opts mount_opts; |
| 74 | }; |
| 75 | |
| 76 | static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts) |
| 77 | { |
| 78 | substring_t args[MAX_OPT_ARGS]; |
| 79 | int option; |
| 80 | int token; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 81 | kuid_t uid; |
| 82 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 83 | char *p; |
| 84 | |
| 85 | opts->mode = DEBUGFS_DEFAULT_MODE; |
| 86 | |
| 87 | while ((p = strsep(&data, ",")) != NULL) { |
| 88 | if (!*p) |
| 89 | continue; |
| 90 | |
| 91 | token = match_token(p, tokens, args); |
| 92 | switch (token) { |
| 93 | case Opt_uid: |
| 94 | if (match_int(&args[0], &option)) |
| 95 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 96 | uid = make_kuid(current_user_ns(), option); |
| 97 | if (!uid_valid(uid)) |
| 98 | return -EINVAL; |
| 99 | opts->uid = uid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 100 | break; |
| 101 | case Opt_gid: |
Dave Reisner | f1688e0 | 2013-01-02 08:54:37 -0500 | [diff] [blame] | 102 | if (match_int(&args[0], &option)) |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 103 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 104 | gid = make_kgid(current_user_ns(), option); |
| 105 | if (!gid_valid(gid)) |
| 106 | return -EINVAL; |
| 107 | opts->gid = gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 108 | break; |
| 109 | case Opt_mode: |
| 110 | if (match_octal(&args[0], &option)) |
| 111 | return -EINVAL; |
| 112 | opts->mode = option & S_IALLUGO; |
| 113 | break; |
| 114 | /* |
| 115 | * We might like to report bad mount options here; |
| 116 | * but traditionally debugfs has ignored all mount options |
| 117 | */ |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | return 0; |
| 122 | } |
| 123 | |
| 124 | static int debugfs_apply_options(struct super_block *sb) |
| 125 | { |
| 126 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 127 | struct inode *inode = d_inode(sb->s_root); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 128 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 129 | |
| 130 | inode->i_mode &= ~S_IALLUGO; |
| 131 | inode->i_mode |= opts->mode; |
| 132 | |
| 133 | inode->i_uid = opts->uid; |
| 134 | inode->i_gid = opts->gid; |
| 135 | |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 139 | static int debugfs_remount(struct super_block *sb, int *flags, char *data) |
| 140 | { |
| 141 | int err; |
| 142 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
| 143 | |
Theodore Ts'o | 02b9984 | 2014-03-13 10:14:33 -0400 | [diff] [blame] | 144 | sync_filesystem(sb); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 145 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 146 | if (err) |
| 147 | goto fail; |
| 148 | |
| 149 | debugfs_apply_options(sb); |
| 150 | |
| 151 | fail: |
| 152 | return err; |
| 153 | } |
| 154 | |
| 155 | static int debugfs_show_options(struct seq_file *m, struct dentry *root) |
| 156 | { |
| 157 | struct debugfs_fs_info *fsi = root->d_sb->s_fs_info; |
| 158 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 159 | |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 160 | if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) |
| 161 | seq_printf(m, ",uid=%u", |
| 162 | from_kuid_munged(&init_user_ns, opts->uid)); |
| 163 | if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) |
| 164 | seq_printf(m, ",gid=%u", |
| 165 | from_kgid_munged(&init_user_ns, opts->gid)); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 166 | if (opts->mode != DEBUGFS_DEFAULT_MODE) |
| 167 | seq_printf(m, ",mode=%o", opts->mode); |
| 168 | |
| 169 | return 0; |
| 170 | } |
| 171 | |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 172 | static void debugfs_evict_inode(struct inode *inode) |
| 173 | { |
| 174 | truncate_inode_pages_final(&inode->i_data); |
| 175 | clear_inode(inode); |
| 176 | if (S_ISLNK(inode->i_mode)) |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame^] | 177 | kfree(inode->i_link); |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 178 | } |
| 179 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 180 | static const struct super_operations debugfs_super_operations = { |
| 181 | .statfs = simple_statfs, |
| 182 | .remount_fs = debugfs_remount, |
| 183 | .show_options = debugfs_show_options, |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 184 | .evict_inode = debugfs_evict_inode, |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 185 | }; |
| 186 | |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 187 | static struct vfsmount *debugfs_automount(struct path *path) |
| 188 | { |
| 189 | struct vfsmount *(*f)(void *); |
| 190 | f = (struct vfsmount *(*)(void *))path->dentry->d_fsdata; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 191 | return f(d_inode(path->dentry)->i_private); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 192 | } |
| 193 | |
| 194 | static const struct dentry_operations debugfs_dops = { |
| 195 | .d_delete = always_delete_dentry, |
| 196 | .d_automount = debugfs_automount, |
| 197 | }; |
| 198 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | static int debug_fill_super(struct super_block *sb, void *data, int silent) |
| 200 | { |
| 201 | static struct tree_descr debug_files[] = {{""}}; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 202 | struct debugfs_fs_info *fsi; |
| 203 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 205 | save_mount_options(sb, data); |
| 206 | |
| 207 | fsi = kzalloc(sizeof(struct debugfs_fs_info), GFP_KERNEL); |
| 208 | sb->s_fs_info = fsi; |
| 209 | if (!fsi) { |
| 210 | err = -ENOMEM; |
| 211 | goto fail; |
| 212 | } |
| 213 | |
| 214 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 215 | if (err) |
| 216 | goto fail; |
| 217 | |
| 218 | err = simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); |
| 219 | if (err) |
| 220 | goto fail; |
| 221 | |
| 222 | sb->s_op = &debugfs_super_operations; |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 223 | sb->s_d_op = &debugfs_dops; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 224 | |
| 225 | debugfs_apply_options(sb); |
| 226 | |
| 227 | return 0; |
| 228 | |
| 229 | fail: |
| 230 | kfree(fsi); |
| 231 | sb->s_fs_info = NULL; |
| 232 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | } |
| 234 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 235 | static struct dentry *debug_mount(struct file_system_type *fs_type, |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 236 | int flags, const char *dev_name, |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 237 | void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | { |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 239 | return mount_single(fs_type, flags, data, debug_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | } |
| 241 | |
| 242 | static struct file_system_type debug_fs_type = { |
| 243 | .owner = THIS_MODULE, |
| 244 | .name = "debugfs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 245 | .mount = debug_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | .kill_sb = kill_litter_super, |
| 247 | }; |
Eric W. Biederman | 7f78e03 | 2013-03-02 19:39:14 -0800 | [diff] [blame] | 248 | MODULE_ALIAS_FS("debugfs"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 250 | static struct dentry *start_creating(const char *name, struct dentry *parent) |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 251 | { |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 252 | struct dentry *dentry; |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 253 | int error; |
| 254 | |
| 255 | pr_debug("debugfs: creating file '%s'\n",name); |
| 256 | |
Greg KH | c9e15f2 | 2015-03-30 14:59:15 +0200 | [diff] [blame] | 257 | if (IS_ERR(parent)) |
| 258 | return parent; |
| 259 | |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 260 | error = simple_pin_fs(&debug_fs_type, &debugfs_mount, |
| 261 | &debugfs_mount_count); |
| 262 | if (error) |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 263 | return ERR_PTR(error); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 264 | |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 265 | /* If the parent is not specified, we create it in the root. |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 266 | * We need the root dentry to do this, which is in the super |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 267 | * block. A pointer to that is in the struct vfsmount that we |
| 268 | * have around. |
| 269 | */ |
| 270 | if (!parent) |
| 271 | parent = debugfs_mount->mnt_root; |
| 272 | |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 273 | mutex_lock(&d_inode(parent)->i_mutex); |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 274 | dentry = lookup_one_len(name, parent, strlen(name)); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 275 | if (!IS_ERR(dentry) && d_really_is_positive(dentry)) { |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 276 | dput(dentry); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 277 | dentry = ERR_PTR(-EEXIST); |
| 278 | } |
| 279 | if (IS_ERR(dentry)) |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 280 | mutex_unlock(&d_inode(parent)->i_mutex); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 281 | return dentry; |
| 282 | } |
| 283 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 284 | static struct dentry *failed_creating(struct dentry *dentry) |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 285 | { |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 286 | mutex_unlock(&d_inode(dentry->d_parent)->i_mutex); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 287 | dput(dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 288 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
| 289 | return NULL; |
| 290 | } |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 291 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 292 | static struct dentry *end_creating(struct dentry *dentry) |
| 293 | { |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 294 | mutex_unlock(&d_inode(dentry->d_parent)->i_mutex); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 295 | return dentry; |
| 296 | } |
| 297 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | /** |
| 299 | * debugfs_create_file - create a file in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | * @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] | 301 | * @mode: the permission that the file should have. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | * @parent: a pointer to the parent dentry for this file. This should be a |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 303 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | * file will be created in the root of the debugfs filesystem. |
| 305 | * @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] | 306 | * on. The inode.i_private pointer will point to this value on |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | * the open() call. |
| 308 | * @fops: a pointer to a struct file_operations that should be used for |
| 309 | * this file. |
| 310 | * |
| 311 | * 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] | 312 | * wide range of flexibility in creating a file, or a directory (if you want |
| 313 | * to create a directory, the debugfs_create_dir() function is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | * recommended to be used instead.) |
| 315 | * |
| 316 | * This function will return a pointer to a dentry if it succeeds. This |
| 317 | * pointer must be passed to the debugfs_remove() function when the file is |
| 318 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 319 | * you are responsible here.) If an error occurs, %NULL will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 321 | * 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] | 322 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | */ |
Al Viro | f4ae40a | 2011-07-24 04:33:43 -0400 | [diff] [blame] | 324 | struct dentry *debugfs_create_file(const char *name, umode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | struct dentry *parent, void *data, |
Arjan van de Ven | 99ac48f | 2006-03-28 01:56:41 -0800 | [diff] [blame] | 326 | const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 328 | struct dentry *dentry; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 329 | struct inode *inode; |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 330 | |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 331 | if (!(mode & S_IFMT)) |
| 332 | mode |= S_IFREG; |
| 333 | BUG_ON(!S_ISREG(mode)); |
| 334 | dentry = start_creating(name, parent); |
| 335 | |
| 336 | if (IS_ERR(dentry)) |
| 337 | return NULL; |
| 338 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 339 | inode = debugfs_get_inode(dentry->d_sb); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 340 | if (unlikely(!inode)) |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 341 | return failed_creating(dentry); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 342 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 343 | inode->i_mode = mode; |
| 344 | inode->i_fop = fops ? fops : &debugfs_file_operations; |
| 345 | inode->i_private = data; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 346 | d_instantiate(dentry, inode); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 347 | fsnotify_create(d_inode(dentry->d_parent), dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 348 | return end_creating(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | } |
| 350 | EXPORT_SYMBOL_GPL(debugfs_create_file); |
| 351 | |
| 352 | /** |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 353 | * debugfs_create_file_size - create a file in the debugfs filesystem |
| 354 | * @name: a pointer to a string containing the name of the file to create. |
| 355 | * @mode: the permission that the file should have. |
| 356 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 357 | * directory dentry if set. If this parameter is NULL, then the |
| 358 | * file will be created in the root of the debugfs filesystem. |
| 359 | * @data: a pointer to something that the caller will want to get to later |
| 360 | * on. The inode.i_private pointer will point to this value on |
| 361 | * the open() call. |
| 362 | * @fops: a pointer to a struct file_operations that should be used for |
| 363 | * this file. |
| 364 | * @file_size: initial file size |
| 365 | * |
| 366 | * This is the basic "create a file" function for debugfs. It allows for a |
| 367 | * wide range of flexibility in creating a file, or a directory (if you want |
| 368 | * to create a directory, the debugfs_create_dir() function is |
| 369 | * recommended to be used instead.) |
| 370 | * |
| 371 | * This function will return a pointer to a dentry if it succeeds. This |
| 372 | * pointer must be passed to the debugfs_remove() function when the file is |
| 373 | * to be removed (no automatic cleanup happens if your module is unloaded, |
| 374 | * you are responsible here.) If an error occurs, %NULL will be returned. |
| 375 | * |
| 376 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 377 | * returned. |
| 378 | */ |
| 379 | struct dentry *debugfs_create_file_size(const char *name, umode_t mode, |
| 380 | struct dentry *parent, void *data, |
| 381 | const struct file_operations *fops, |
| 382 | loff_t file_size) |
| 383 | { |
| 384 | struct dentry *de = debugfs_create_file(name, mode, parent, data, fops); |
| 385 | |
| 386 | if (de) |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 387 | d_inode(de)->i_size = file_size; |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 388 | return de; |
| 389 | } |
| 390 | EXPORT_SYMBOL_GPL(debugfs_create_file_size); |
| 391 | |
| 392 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | * debugfs_create_dir - create a directory in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | * @name: a pointer to a string containing the name of the directory to |
| 395 | * create. |
| 396 | * @parent: a pointer to the parent dentry for this file. This should be a |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 397 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | * directory will be created in the root of the debugfs filesystem. |
| 399 | * |
| 400 | * This function creates a directory in debugfs with the given name. |
| 401 | * |
| 402 | * This function will return a pointer to a dentry if it succeeds. This |
| 403 | * pointer must be passed to the debugfs_remove() function when the file is |
| 404 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 405 | * you are responsible here.) If an error occurs, %NULL will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 407 | * 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] | 408 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | */ |
| 410 | struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) |
| 411 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 412 | struct dentry *dentry = start_creating(name, parent); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 413 | struct inode *inode; |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 414 | |
| 415 | if (IS_ERR(dentry)) |
| 416 | return NULL; |
| 417 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 418 | inode = debugfs_get_inode(dentry->d_sb); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 419 | if (unlikely(!inode)) |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 420 | return failed_creating(dentry); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 421 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 422 | inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; |
| 423 | inode->i_op = &simple_dir_inode_operations; |
| 424 | inode->i_fop = &simple_dir_operations; |
| 425 | |
| 426 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 427 | inc_nlink(inode); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 428 | d_instantiate(dentry, inode); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 429 | inc_nlink(d_inode(dentry->d_parent)); |
| 430 | fsnotify_mkdir(d_inode(dentry->d_parent), dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 431 | return end_creating(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | } |
| 433 | EXPORT_SYMBOL_GPL(debugfs_create_dir); |
| 434 | |
| 435 | /** |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 436 | * debugfs_create_automount - create automount point in the debugfs filesystem |
| 437 | * @name: a pointer to a string containing the name of the file to create. |
| 438 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 439 | * directory dentry if set. If this parameter is NULL, then the |
| 440 | * file will be created in the root of the debugfs filesystem. |
| 441 | * @f: function to be called when pathname resolution steps on that one. |
| 442 | * @data: opaque argument to pass to f(). |
| 443 | * |
| 444 | * @f should return what ->d_automount() would. |
| 445 | */ |
| 446 | struct dentry *debugfs_create_automount(const char *name, |
| 447 | struct dentry *parent, |
| 448 | struct vfsmount *(*f)(void *), |
| 449 | void *data) |
| 450 | { |
| 451 | struct dentry *dentry = start_creating(name, parent); |
| 452 | struct inode *inode; |
| 453 | |
| 454 | if (IS_ERR(dentry)) |
| 455 | return NULL; |
| 456 | |
| 457 | inode = debugfs_get_inode(dentry->d_sb); |
| 458 | if (unlikely(!inode)) |
| 459 | return failed_creating(dentry); |
| 460 | |
| 461 | inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; |
| 462 | inode->i_flags |= S_AUTOMOUNT; |
| 463 | inode->i_private = data; |
| 464 | dentry->d_fsdata = (void *)f; |
| 465 | d_instantiate(dentry, inode); |
| 466 | return end_creating(dentry); |
| 467 | } |
| 468 | EXPORT_SYMBOL(debugfs_create_automount); |
| 469 | |
| 470 | /** |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 471 | * debugfs_create_symlink- create a symbolic link in the debugfs filesystem |
| 472 | * @name: a pointer to a string containing the name of the symbolic link to |
| 473 | * create. |
| 474 | * @parent: a pointer to the parent dentry for this symbolic link. This |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 475 | * should be a directory dentry if set. If this parameter is NULL, |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 476 | * then the symbolic link will be created in the root of the debugfs |
| 477 | * filesystem. |
| 478 | * @target: a pointer to a string containing the path to the target of the |
| 479 | * symbolic link. |
| 480 | * |
| 481 | * This function creates a symbolic link with the given name in debugfs that |
| 482 | * links to the given target path. |
| 483 | * |
| 484 | * This function will return a pointer to a dentry if it succeeds. This |
| 485 | * pointer must be passed to the debugfs_remove() function when the symbolic |
| 486 | * link is to be removed (no automatic cleanup happens if your module is |
| 487 | * unloaded, you are responsible here.) If an error occurs, %NULL will be |
| 488 | * returned. |
| 489 | * |
| 490 | * 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] | 491 | * returned. |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 492 | */ |
| 493 | struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, |
| 494 | const char *target) |
| 495 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 496 | struct dentry *dentry; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 497 | struct inode *inode; |
| 498 | char *link = kstrdup(target, GFP_KERNEL); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 499 | if (!link) |
| 500 | return NULL; |
| 501 | |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 502 | dentry = start_creating(name, parent); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 503 | if (IS_ERR(dentry)) { |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 504 | kfree(link); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 505 | return NULL; |
| 506 | } |
| 507 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 508 | inode = debugfs_get_inode(dentry->d_sb); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 509 | if (unlikely(!inode)) { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 510 | kfree(link); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 511 | return failed_creating(dentry); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 512 | } |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 513 | inode->i_mode = S_IFLNK | S_IRWXUGO; |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame^] | 514 | inode->i_op = &simple_symlink_inode_operations; |
| 515 | inode->i_link = link; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 516 | d_instantiate(dentry, inode); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 517 | return end_creating(dentry); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 518 | } |
| 519 | EXPORT_SYMBOL_GPL(debugfs_create_symlink); |
| 520 | |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 521 | static int __debugfs_remove(struct dentry *dentry, struct dentry *parent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | { |
Mathieu Desnoyers | 65c3333 | 2006-11-24 13:50:09 -0500 | [diff] [blame] | 523 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | if (debugfs_positive(dentry)) { |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 526 | dget(dentry); |
David Howells | 7ceab50 | 2015-03-05 12:46:49 +0000 | [diff] [blame] | 527 | if (d_is_dir(dentry)) |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 528 | ret = simple_rmdir(d_inode(parent), dentry); |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 529 | else |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 530 | simple_unlink(d_inode(parent), dentry); |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 531 | if (!ret) |
| 532 | d_delete(dentry); |
| 533 | dput(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | } |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 535 | return ret; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 536 | } |
| 537 | |
| 538 | /** |
| 539 | * debugfs_remove - removes a file or directory from the debugfs filesystem |
| 540 | * @dentry: a pointer to a the dentry of the file or directory to be |
| 541 | * removed. |
| 542 | * |
| 543 | * This function removes a file or directory in debugfs that was previously |
| 544 | * created with a call to another debugfs function (like |
| 545 | * debugfs_create_file() or variants thereof.) |
| 546 | * |
| 547 | * This function is required to be called in order for the file to be |
| 548 | * removed, no automatic cleanup of files will happen when a module is |
| 549 | * removed, you are responsible here. |
| 550 | */ |
| 551 | void debugfs_remove(struct dentry *dentry) |
| 552 | { |
| 553 | struct dentry *parent; |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 554 | int ret; |
| 555 | |
Arend van Spriel | a59d629 | 2012-05-23 15:13:07 +0200 | [diff] [blame] | 556 | if (IS_ERR_OR_NULL(dentry)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 557 | return; |
| 558 | |
| 559 | parent = dentry->d_parent; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 560 | if (!parent || d_really_is_negative(parent)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 561 | return; |
| 562 | |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 563 | mutex_lock(&d_inode(parent)->i_mutex); |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 564 | ret = __debugfs_remove(dentry, parent); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 565 | mutex_unlock(&d_inode(parent)->i_mutex); |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 566 | if (!ret) |
| 567 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | } |
| 569 | EXPORT_SYMBOL_GPL(debugfs_remove); |
| 570 | |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 571 | /** |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 572 | * debugfs_remove_recursive - recursively removes a directory |
| 573 | * @dentry: a pointer to a the dentry of the directory to be removed. |
| 574 | * |
| 575 | * This function recursively removes a directory tree in debugfs that |
| 576 | * was previously created with a call to another debugfs function |
| 577 | * (like debugfs_create_file() or variants thereof.) |
| 578 | * |
| 579 | * This function is required to be called in order for the file to be |
| 580 | * removed, no automatic cleanup of files will happen when a module is |
| 581 | * removed, you are responsible here. |
| 582 | */ |
| 583 | void debugfs_remove_recursive(struct dentry *dentry) |
| 584 | { |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 585 | struct dentry *child, *parent; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 586 | |
Arend van Spriel | a59d629 | 2012-05-23 15:13:07 +0200 | [diff] [blame] | 587 | if (IS_ERR_OR_NULL(dentry)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 588 | return; |
| 589 | |
| 590 | parent = dentry->d_parent; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 591 | if (!parent || d_really_is_negative(parent)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 592 | return; |
| 593 | |
| 594 | parent = dentry; |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 595 | down: |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 596 | mutex_lock(&d_inode(parent)->i_mutex); |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 597 | loop: |
| 598 | /* |
| 599 | * The parent->d_subdirs is protected by the d_lock. Outside that |
| 600 | * lock, the child can be unlinked and set to be freed which can |
| 601 | * use the d_u.d_child as the rcu head and corrupt this list. |
| 602 | */ |
| 603 | spin_lock(&parent->d_lock); |
Al Viro | 946e51f | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 604 | list_for_each_entry(child, &parent->d_subdirs, d_child) { |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 605 | if (!debugfs_positive(child)) |
| 606 | continue; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 607 | |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 608 | /* perhaps simple_empty(child) makes more sense */ |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 609 | if (!list_empty(&child->d_subdirs)) { |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 610 | spin_unlock(&parent->d_lock); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 611 | mutex_unlock(&d_inode(parent)->i_mutex); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 612 | parent = child; |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 613 | goto down; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 614 | } |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 615 | |
| 616 | spin_unlock(&parent->d_lock); |
| 617 | |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 618 | if (!__debugfs_remove(child, parent)) |
| 619 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 620 | |
| 621 | /* |
| 622 | * The parent->d_lock protects agaist child from unlinking |
| 623 | * from d_subdirs. When releasing the parent->d_lock we can |
| 624 | * no longer trust that the next pointer is valid. |
| 625 | * Restart the loop. We'll skip this one with the |
| 626 | * debugfs_positive() check. |
| 627 | */ |
| 628 | goto loop; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 629 | } |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 630 | spin_unlock(&parent->d_lock); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 631 | |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 632 | mutex_unlock(&d_inode(parent)->i_mutex); |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 633 | child = parent; |
| 634 | parent = parent->d_parent; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 635 | mutex_lock(&d_inode(parent)->i_mutex); |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 636 | |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 637 | if (child != dentry) |
| 638 | /* go up */ |
| 639 | goto loop; |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 640 | |
| 641 | if (!__debugfs_remove(child, parent)) |
| 642 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 643 | mutex_unlock(&d_inode(parent)->i_mutex); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 644 | } |
| 645 | EXPORT_SYMBOL_GPL(debugfs_remove_recursive); |
| 646 | |
| 647 | /** |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 648 | * debugfs_rename - rename a file/directory in the debugfs filesystem |
| 649 | * @old_dir: a pointer to the parent dentry for the renamed object. This |
| 650 | * should be a directory dentry. |
| 651 | * @old_dentry: dentry of an object to be renamed. |
| 652 | * @new_dir: a pointer to the parent dentry where the object should be |
| 653 | * moved. This should be a directory dentry. |
| 654 | * @new_name: a pointer to a string containing the target name. |
| 655 | * |
| 656 | * This function renames a file/directory in debugfs. The target must not |
| 657 | * exist for rename to succeed. |
| 658 | * |
| 659 | * This function will return a pointer to old_dentry (which is updated to |
| 660 | * reflect renaming) if it succeeds. If an error occurs, %NULL will be |
| 661 | * returned. |
| 662 | * |
| 663 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 664 | * returned. |
| 665 | */ |
| 666 | struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, |
| 667 | struct dentry *new_dir, const char *new_name) |
| 668 | { |
| 669 | int error; |
| 670 | struct dentry *dentry = NULL, *trap; |
| 671 | const char *old_name; |
| 672 | |
| 673 | trap = lock_rename(new_dir, old_dir); |
| 674 | /* Source or destination directories don't exist? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 675 | if (d_really_is_negative(old_dir) || d_really_is_negative(new_dir)) |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 676 | goto exit; |
| 677 | /* Source does not exist, cyclic rename, or mountpoint? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 678 | if (d_really_is_negative(old_dentry) || old_dentry == trap || |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 679 | d_mountpoint(old_dentry)) |
| 680 | goto exit; |
| 681 | dentry = lookup_one_len(new_name, new_dir, strlen(new_name)); |
| 682 | /* Lookup failed, cyclic rename or target exists? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 683 | if (IS_ERR(dentry) || dentry == trap || d_really_is_positive(dentry)) |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 684 | goto exit; |
| 685 | |
| 686 | old_name = fsnotify_oldname_init(old_dentry->d_name.name); |
| 687 | |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 688 | error = simple_rename(d_inode(old_dir), old_dentry, d_inode(new_dir), |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 689 | dentry); |
| 690 | if (error) { |
| 691 | fsnotify_oldname_free(old_name); |
| 692 | goto exit; |
| 693 | } |
| 694 | d_move(old_dentry, dentry); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 695 | fsnotify_move(d_inode(old_dir), d_inode(new_dir), old_name, |
David Howells | e36cb0b | 2015-01-29 12:02:35 +0000 | [diff] [blame] | 696 | d_is_dir(old_dentry), |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 697 | NULL, old_dentry); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 698 | fsnotify_oldname_free(old_name); |
| 699 | unlock_rename(new_dir, old_dir); |
| 700 | dput(dentry); |
| 701 | return old_dentry; |
| 702 | exit: |
| 703 | if (dentry && !IS_ERR(dentry)) |
| 704 | dput(dentry); |
| 705 | unlock_rename(new_dir, old_dir); |
| 706 | return NULL; |
| 707 | } |
| 708 | EXPORT_SYMBOL_GPL(debugfs_rename); |
| 709 | |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 710 | /** |
| 711 | * debugfs_initialized - Tells whether debugfs has been registered |
| 712 | */ |
| 713 | bool debugfs_initialized(void) |
| 714 | { |
| 715 | return debugfs_registered; |
| 716 | } |
| 717 | EXPORT_SYMBOL_GPL(debugfs_initialized); |
| 718 | |
| 719 | |
Greg Kroah-Hartman | 191e186 | 2007-10-29 20:13:17 +0100 | [diff] [blame] | 720 | static struct kobject *debug_kobj; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | |
| 722 | static int __init debugfs_init(void) |
| 723 | { |
| 724 | int retval; |
| 725 | |
Greg Kroah-Hartman | 0ff21e4 | 2007-11-06 10:36:58 -0800 | [diff] [blame] | 726 | debug_kobj = kobject_create_and_add("debug", kernel_kobj); |
Greg Kroah-Hartman | 191e186 | 2007-10-29 20:13:17 +0100 | [diff] [blame] | 727 | if (!debug_kobj) |
| 728 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 729 | |
| 730 | retval = register_filesystem(&debug_fs_type); |
| 731 | if (retval) |
Greg Kroah-Hartman | 197b12d | 2007-12-20 08:13:05 -0800 | [diff] [blame] | 732 | kobject_put(debug_kobj); |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 733 | else |
| 734 | debugfs_registered = true; |
| 735 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | return retval; |
| 737 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 738 | core_initcall(debugfs_init); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | |