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. |
Mauro Carvalho Chehab | e1511a8 | 2017-05-14 12:09:53 -0300 | [diff] [blame] | 12 | * See ./Documentation/core-api/kernel-api.rst for more details. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Nicolai Stange | 9fd4dce | 2016-03-22 14:11:13 +0100 | [diff] [blame] | 30 | |
| 31 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
Kees Cook | 82aceae4 | 2012-08-27 13:32:15 -0700 | [diff] [blame] | 33 | #define DEBUGFS_DEFAULT_MODE 0700 |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 34 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | static struct vfsmount *debugfs_mount; |
| 36 | static int debugfs_mount_count; |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 37 | static bool debugfs_registered; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 39 | static struct inode *debugfs_get_inode(struct super_block *sb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | { |
| 41 | struct inode *inode = new_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 43 | inode->i_ino = get_next_ino(); |
Deepa Dinamani | 1b48b53 | 2016-02-22 07:17:47 -0800 | [diff] [blame] | 44 | inode->i_atime = inode->i_mtime = |
Deepa Dinamani | c2050a4 | 2016-09-14 07:48:06 -0700 | [diff] [blame] | 45 | inode->i_ctime = current_time(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | } |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 47 | return inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | } |
| 49 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 50 | struct debugfs_mount_opts { |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 51 | kuid_t uid; |
| 52 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 53 | umode_t mode; |
| 54 | }; |
| 55 | |
| 56 | enum { |
| 57 | Opt_uid, |
| 58 | Opt_gid, |
| 59 | Opt_mode, |
| 60 | Opt_err |
| 61 | }; |
| 62 | |
| 63 | static const match_table_t tokens = { |
| 64 | {Opt_uid, "uid=%u"}, |
| 65 | {Opt_gid, "gid=%u"}, |
| 66 | {Opt_mode, "mode=%o"}, |
| 67 | {Opt_err, NULL} |
| 68 | }; |
| 69 | |
| 70 | struct debugfs_fs_info { |
| 71 | struct debugfs_mount_opts mount_opts; |
| 72 | }; |
| 73 | |
| 74 | static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts) |
| 75 | { |
| 76 | substring_t args[MAX_OPT_ARGS]; |
| 77 | int option; |
| 78 | int token; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 79 | kuid_t uid; |
| 80 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 81 | char *p; |
| 82 | |
| 83 | opts->mode = DEBUGFS_DEFAULT_MODE; |
| 84 | |
| 85 | while ((p = strsep(&data, ",")) != NULL) { |
| 86 | if (!*p) |
| 87 | continue; |
| 88 | |
| 89 | token = match_token(p, tokens, args); |
| 90 | switch (token) { |
| 91 | case Opt_uid: |
| 92 | if (match_int(&args[0], &option)) |
| 93 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 94 | uid = make_kuid(current_user_ns(), option); |
| 95 | if (!uid_valid(uid)) |
| 96 | return -EINVAL; |
| 97 | opts->uid = uid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 98 | break; |
| 99 | case Opt_gid: |
Dave Reisner | f1688e0 | 2013-01-02 08:54:37 -0500 | [diff] [blame] | 100 | if (match_int(&args[0], &option)) |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 101 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 102 | gid = make_kgid(current_user_ns(), option); |
| 103 | if (!gid_valid(gid)) |
| 104 | return -EINVAL; |
| 105 | opts->gid = gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 106 | break; |
| 107 | case Opt_mode: |
| 108 | if (match_octal(&args[0], &option)) |
| 109 | return -EINVAL; |
| 110 | opts->mode = option & S_IALLUGO; |
| 111 | break; |
| 112 | /* |
| 113 | * We might like to report bad mount options here; |
| 114 | * but traditionally debugfs has ignored all mount options |
| 115 | */ |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | static int debugfs_apply_options(struct super_block *sb) |
| 123 | { |
| 124 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 125 | struct inode *inode = d_inode(sb->s_root); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 126 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 127 | |
| 128 | inode->i_mode &= ~S_IALLUGO; |
| 129 | inode->i_mode |= opts->mode; |
| 130 | |
| 131 | inode->i_uid = opts->uid; |
| 132 | inode->i_gid = opts->gid; |
| 133 | |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | static int debugfs_remount(struct super_block *sb, int *flags, char *data) |
| 138 | { |
| 139 | int err; |
| 140 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
| 141 | |
Theodore Ts'o | 02b9984 | 2014-03-13 10:14:33 -0400 | [diff] [blame] | 142 | sync_filesystem(sb); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 143 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 144 | if (err) |
| 145 | goto fail; |
| 146 | |
| 147 | debugfs_apply_options(sb); |
| 148 | |
| 149 | fail: |
| 150 | return err; |
| 151 | } |
| 152 | |
| 153 | static int debugfs_show_options(struct seq_file *m, struct dentry *root) |
| 154 | { |
| 155 | struct debugfs_fs_info *fsi = root->d_sb->s_fs_info; |
| 156 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 157 | |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 158 | if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) |
| 159 | seq_printf(m, ",uid=%u", |
| 160 | from_kuid_munged(&init_user_ns, opts->uid)); |
| 161 | if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) |
| 162 | seq_printf(m, ",gid=%u", |
| 163 | from_kgid_munged(&init_user_ns, opts->gid)); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 164 | if (opts->mode != DEBUGFS_DEFAULT_MODE) |
| 165 | seq_printf(m, ",mode=%o", opts->mode); |
| 166 | |
| 167 | return 0; |
| 168 | } |
| 169 | |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 170 | static void debugfs_evict_inode(struct inode *inode) |
| 171 | { |
| 172 | truncate_inode_pages_final(&inode->i_data); |
| 173 | clear_inode(inode); |
| 174 | if (S_ISLNK(inode->i_mode)) |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame] | 175 | kfree(inode->i_link); |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 176 | } |
| 177 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 178 | static const struct super_operations debugfs_super_operations = { |
| 179 | .statfs = simple_statfs, |
| 180 | .remount_fs = debugfs_remount, |
| 181 | .show_options = debugfs_show_options, |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 182 | .evict_inode = debugfs_evict_inode, |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 183 | }; |
| 184 | |
Nicolai Stange | 7c8d469 | 2017-10-31 00:15:47 +0100 | [diff] [blame] | 185 | static void debugfs_release_dentry(struct dentry *dentry) |
| 186 | { |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame^] | 187 | void *fsd = dentry->d_fsdata; |
| 188 | |
| 189 | if (!((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) |
| 190 | kfree(dentry->d_fsdata); |
Nicolai Stange | 7c8d469 | 2017-10-31 00:15:47 +0100 | [diff] [blame] | 191 | } |
| 192 | |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 193 | static struct vfsmount *debugfs_automount(struct path *path) |
| 194 | { |
Eric W. Biederman | 93faccbb | 2017-02-01 06:06:16 +1300 | [diff] [blame] | 195 | debugfs_automount_t f; |
| 196 | f = (debugfs_automount_t)path->dentry->d_fsdata; |
| 197 | return f(path->dentry, d_inode(path->dentry)->i_private); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 198 | } |
| 199 | |
| 200 | static const struct dentry_operations debugfs_dops = { |
| 201 | .d_delete = always_delete_dentry, |
Nicolai Stange | 7c8d469 | 2017-10-31 00:15:47 +0100 | [diff] [blame] | 202 | .d_release = debugfs_release_dentry, |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 203 | .d_automount = debugfs_automount, |
| 204 | }; |
| 205 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | static int debug_fill_super(struct super_block *sb, void *data, int silent) |
| 207 | { |
Eric Biggers | cda3712 | 2017-03-25 21:15:37 -0700 | [diff] [blame] | 208 | static const struct tree_descr debug_files[] = {{""}}; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 209 | struct debugfs_fs_info *fsi; |
| 210 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 212 | fsi = kzalloc(sizeof(struct debugfs_fs_info), GFP_KERNEL); |
| 213 | sb->s_fs_info = fsi; |
| 214 | if (!fsi) { |
| 215 | err = -ENOMEM; |
| 216 | goto fail; |
| 217 | } |
| 218 | |
| 219 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 220 | if (err) |
| 221 | goto fail; |
| 222 | |
| 223 | err = simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); |
| 224 | if (err) |
| 225 | goto fail; |
| 226 | |
| 227 | sb->s_op = &debugfs_super_operations; |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 228 | sb->s_d_op = &debugfs_dops; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 229 | |
| 230 | debugfs_apply_options(sb); |
| 231 | |
| 232 | return 0; |
| 233 | |
| 234 | fail: |
| 235 | kfree(fsi); |
| 236 | sb->s_fs_info = NULL; |
| 237 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | } |
| 239 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 240 | static struct dentry *debug_mount(struct file_system_type *fs_type, |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 241 | int flags, const char *dev_name, |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 242 | void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | { |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 244 | return mount_single(fs_type, flags, data, debug_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | } |
| 246 | |
| 247 | static struct file_system_type debug_fs_type = { |
| 248 | .owner = THIS_MODULE, |
| 249 | .name = "debugfs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 250 | .mount = debug_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | .kill_sb = kill_litter_super, |
| 252 | }; |
Eric W. Biederman | 7f78e03 | 2013-03-02 19:39:14 -0800 | [diff] [blame] | 253 | MODULE_ALIAS_FS("debugfs"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | |
Omar Sandoval | a7c5437 | 2017-01-31 14:53:17 -0800 | [diff] [blame] | 255 | /** |
| 256 | * debugfs_lookup() - look up an existing debugfs file |
| 257 | * @name: a pointer to a string containing the name of the file to look up. |
| 258 | * @parent: a pointer to the parent dentry of the file. |
| 259 | * |
| 260 | * This function will return a pointer to a dentry if it succeeds. If the file |
| 261 | * doesn't exist or an error occurs, %NULL will be returned. The returned |
| 262 | * dentry must be passed to dput() when it is no longer needed. |
| 263 | * |
| 264 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 265 | * returned. |
| 266 | */ |
| 267 | struct dentry *debugfs_lookup(const char *name, struct dentry *parent) |
| 268 | { |
| 269 | struct dentry *dentry; |
| 270 | |
| 271 | if (IS_ERR(parent)) |
| 272 | return NULL; |
| 273 | |
| 274 | if (!parent) |
| 275 | parent = debugfs_mount->mnt_root; |
| 276 | |
| 277 | inode_lock(d_inode(parent)); |
| 278 | dentry = lookup_one_len(name, parent, strlen(name)); |
| 279 | inode_unlock(d_inode(parent)); |
| 280 | |
| 281 | if (IS_ERR(dentry)) |
| 282 | return NULL; |
| 283 | if (!d_really_is_positive(dentry)) { |
| 284 | dput(dentry); |
| 285 | return NULL; |
| 286 | } |
| 287 | return dentry; |
| 288 | } |
| 289 | EXPORT_SYMBOL_GPL(debugfs_lookup); |
| 290 | |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 291 | static struct dentry *start_creating(const char *name, struct dentry *parent) |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 292 | { |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 293 | struct dentry *dentry; |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 294 | int error; |
| 295 | |
| 296 | pr_debug("debugfs: creating file '%s'\n",name); |
| 297 | |
Greg KH | c9e15f2 | 2015-03-30 14:59:15 +0200 | [diff] [blame] | 298 | if (IS_ERR(parent)) |
| 299 | return parent; |
| 300 | |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 301 | error = simple_pin_fs(&debug_fs_type, &debugfs_mount, |
| 302 | &debugfs_mount_count); |
| 303 | if (error) |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 304 | return ERR_PTR(error); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 305 | |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 306 | /* If the parent is not specified, we create it in the root. |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 307 | * 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] | 308 | * block. A pointer to that is in the struct vfsmount that we |
| 309 | * have around. |
| 310 | */ |
| 311 | if (!parent) |
| 312 | parent = debugfs_mount->mnt_root; |
| 313 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 314 | inode_lock(d_inode(parent)); |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 315 | dentry = lookup_one_len(name, parent, strlen(name)); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 316 | if (!IS_ERR(dentry) && d_really_is_positive(dentry)) { |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 317 | dput(dentry); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 318 | dentry = ERR_PTR(-EEXIST); |
| 319 | } |
Daniel Borkmann | 0ee9608 | 2015-11-05 00:01:51 +0100 | [diff] [blame] | 320 | |
| 321 | if (IS_ERR(dentry)) { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 322 | inode_unlock(d_inode(parent)); |
Daniel Borkmann | 0ee9608 | 2015-11-05 00:01:51 +0100 | [diff] [blame] | 323 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
| 324 | } |
| 325 | |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 326 | return dentry; |
| 327 | } |
| 328 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 329 | static struct dentry *failed_creating(struct dentry *dentry) |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 330 | { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 331 | inode_unlock(d_inode(dentry->d_parent)); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 332 | dput(dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 333 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
| 334 | return NULL; |
| 335 | } |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 336 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 337 | static struct dentry *end_creating(struct dentry *dentry) |
| 338 | { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 339 | inode_unlock(d_inode(dentry->d_parent)); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 340 | return dentry; |
| 341 | } |
| 342 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 343 | static struct dentry *__debugfs_create_file(const char *name, umode_t mode, |
| 344 | struct dentry *parent, void *data, |
| 345 | const struct file_operations *proxy_fops, |
| 346 | const struct file_operations *real_fops) |
| 347 | { |
| 348 | struct dentry *dentry; |
| 349 | struct inode *inode; |
| 350 | |
| 351 | if (!(mode & S_IFMT)) |
| 352 | mode |= S_IFREG; |
| 353 | BUG_ON(!S_ISREG(mode)); |
| 354 | dentry = start_creating(name, parent); |
| 355 | |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame^] | 356 | if (IS_ERR(dentry)) |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 357 | return NULL; |
| 358 | |
| 359 | inode = debugfs_get_inode(dentry->d_sb); |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame^] | 360 | if (unlikely(!inode)) |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 361 | return failed_creating(dentry); |
| 362 | |
| 363 | inode->i_mode = mode; |
| 364 | inode->i_private = data; |
| 365 | |
| 366 | inode->i_fop = proxy_fops; |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame^] | 367 | dentry->d_fsdata = (void *)((unsigned long)real_fops | |
| 368 | DEBUGFS_FSDATA_IS_REAL_FOPS_BIT); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 369 | |
| 370 | d_instantiate(dentry, inode); |
| 371 | fsnotify_create(d_inode(dentry->d_parent), dentry); |
| 372 | return end_creating(dentry); |
| 373 | } |
| 374 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | /** |
| 376 | * debugfs_create_file - create a file in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | * @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] | 378 | * @mode: the permission that the file should have. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | * @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] | 380 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | * file will be created in the root of the debugfs filesystem. |
| 382 | * @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] | 383 | * on. The inode.i_private pointer will point to this value on |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | * the open() call. |
| 385 | * @fops: a pointer to a struct file_operations that should be used for |
| 386 | * this file. |
| 387 | * |
| 388 | * 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] | 389 | * wide range of flexibility in creating a file, or a directory (if you want |
| 390 | * to create a directory, the debugfs_create_dir() function is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | * recommended to be used instead.) |
| 392 | * |
| 393 | * This function will return a pointer to a dentry if it succeeds. This |
| 394 | * pointer must be passed to the debugfs_remove() function when the file is |
| 395 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 396 | * you are responsible here.) If an error occurs, %NULL will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 397 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 398 | * 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] | 399 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | */ |
Al Viro | f4ae40a6 | 2011-07-24 04:33:43 -0400 | [diff] [blame] | 401 | struct dentry *debugfs_create_file(const char *name, umode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | struct dentry *parent, void *data, |
Arjan van de Ven | 99ac48f | 2006-03-28 01:56:41 -0800 | [diff] [blame] | 403 | const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | { |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 405 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 406 | return __debugfs_create_file(name, mode, parent, data, |
| 407 | fops ? &debugfs_full_proxy_file_operations : |
| 408 | &debugfs_noop_file_operations, |
| 409 | fops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | } |
| 411 | EXPORT_SYMBOL_GPL(debugfs_create_file); |
| 412 | |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 413 | /** |
| 414 | * debugfs_create_file_unsafe - create a file in the debugfs filesystem |
| 415 | * @name: a pointer to a string containing the name of the file to create. |
| 416 | * @mode: the permission that the file should have. |
| 417 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 418 | * directory dentry if set. If this parameter is NULL, then the |
| 419 | * file will be created in the root of the debugfs filesystem. |
| 420 | * @data: a pointer to something that the caller will want to get to later |
| 421 | * on. The inode.i_private pointer will point to this value on |
| 422 | * the open() call. |
| 423 | * @fops: a pointer to a struct file_operations that should be used for |
| 424 | * this file. |
| 425 | * |
| 426 | * debugfs_create_file_unsafe() is completely analogous to |
| 427 | * debugfs_create_file(), the only difference being that the fops |
| 428 | * handed it will not get protected against file removals by the |
| 429 | * debugfs core. |
| 430 | * |
| 431 | * It is your responsibility to protect your struct file_operation |
| 432 | * methods against file removals by means of debugfs_use_file_start() |
| 433 | * and debugfs_use_file_finish(). ->open() is still protected by |
| 434 | * debugfs though. |
| 435 | * |
| 436 | * Any struct file_operations defined by means of |
| 437 | * DEFINE_DEBUGFS_ATTRIBUTE() is protected against file removals and |
| 438 | * thus, may be used here. |
| 439 | */ |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 440 | struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, |
| 441 | struct dentry *parent, void *data, |
| 442 | const struct file_operations *fops) |
| 443 | { |
| 444 | |
| 445 | return __debugfs_create_file(name, mode, parent, data, |
| 446 | fops ? &debugfs_open_proxy_file_operations : |
| 447 | &debugfs_noop_file_operations, |
| 448 | fops); |
| 449 | } |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 450 | EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 451 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | /** |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 453 | * debugfs_create_file_size - create a file in the debugfs filesystem |
| 454 | * @name: a pointer to a string containing the name of the file to create. |
| 455 | * @mode: the permission that the file should have. |
| 456 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 457 | * directory dentry if set. If this parameter is NULL, then the |
| 458 | * file will be created in the root of the debugfs filesystem. |
| 459 | * @data: a pointer to something that the caller will want to get to later |
| 460 | * on. The inode.i_private pointer will point to this value on |
| 461 | * the open() call. |
| 462 | * @fops: a pointer to a struct file_operations that should be used for |
| 463 | * this file. |
| 464 | * @file_size: initial file size |
| 465 | * |
| 466 | * This is the basic "create a file" function for debugfs. It allows for a |
| 467 | * wide range of flexibility in creating a file, or a directory (if you want |
| 468 | * to create a directory, the debugfs_create_dir() function is |
| 469 | * recommended to be used instead.) |
| 470 | * |
| 471 | * This function will return a pointer to a dentry if it succeeds. This |
| 472 | * pointer must be passed to the debugfs_remove() function when the file is |
| 473 | * to be removed (no automatic cleanup happens if your module is unloaded, |
| 474 | * you are responsible here.) If an error occurs, %NULL will be returned. |
| 475 | * |
| 476 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 477 | * returned. |
| 478 | */ |
| 479 | struct dentry *debugfs_create_file_size(const char *name, umode_t mode, |
| 480 | struct dentry *parent, void *data, |
| 481 | const struct file_operations *fops, |
| 482 | loff_t file_size) |
| 483 | { |
| 484 | struct dentry *de = debugfs_create_file(name, mode, parent, data, fops); |
| 485 | |
| 486 | if (de) |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 487 | d_inode(de)->i_size = file_size; |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 488 | return de; |
| 489 | } |
| 490 | EXPORT_SYMBOL_GPL(debugfs_create_file_size); |
| 491 | |
| 492 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | * debugfs_create_dir - create a directory in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | * @name: a pointer to a string containing the name of the directory to |
| 495 | * create. |
| 496 | * @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] | 497 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | * directory will be created in the root of the debugfs filesystem. |
| 499 | * |
| 500 | * This function creates a directory in debugfs with the given name. |
| 501 | * |
| 502 | * This function will return a pointer to a dentry if it succeeds. This |
| 503 | * pointer must be passed to the debugfs_remove() function when the file is |
| 504 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 505 | * you are responsible here.) If an error occurs, %NULL will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 507 | * 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] | 508 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | */ |
| 510 | struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) |
| 511 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 512 | struct dentry *dentry = start_creating(name, parent); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 513 | struct inode *inode; |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 514 | |
| 515 | if (IS_ERR(dentry)) |
| 516 | return NULL; |
| 517 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 518 | inode = debugfs_get_inode(dentry->d_sb); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 519 | if (unlikely(!inode)) |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 520 | return failed_creating(dentry); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 521 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 522 | inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; |
| 523 | inode->i_op = &simple_dir_inode_operations; |
| 524 | inode->i_fop = &simple_dir_operations; |
| 525 | |
| 526 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 527 | inc_nlink(inode); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 528 | d_instantiate(dentry, inode); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 529 | inc_nlink(d_inode(dentry->d_parent)); |
| 530 | fsnotify_mkdir(d_inode(dentry->d_parent), dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 531 | return end_creating(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | } |
| 533 | EXPORT_SYMBOL_GPL(debugfs_create_dir); |
| 534 | |
| 535 | /** |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 536 | * debugfs_create_automount - create automount point in the debugfs filesystem |
| 537 | * @name: a pointer to a string containing the name of the file to create. |
| 538 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 539 | * directory dentry if set. If this parameter is NULL, then the |
| 540 | * file will be created in the root of the debugfs filesystem. |
| 541 | * @f: function to be called when pathname resolution steps on that one. |
| 542 | * @data: opaque argument to pass to f(). |
| 543 | * |
| 544 | * @f should return what ->d_automount() would. |
| 545 | */ |
| 546 | struct dentry *debugfs_create_automount(const char *name, |
| 547 | struct dentry *parent, |
Eric W. Biederman | 93faccbb | 2017-02-01 06:06:16 +1300 | [diff] [blame] | 548 | debugfs_automount_t f, |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 549 | void *data) |
| 550 | { |
| 551 | struct dentry *dentry = start_creating(name, parent); |
| 552 | struct inode *inode; |
| 553 | |
| 554 | if (IS_ERR(dentry)) |
| 555 | return NULL; |
| 556 | |
| 557 | inode = debugfs_get_inode(dentry->d_sb); |
| 558 | if (unlikely(!inode)) |
| 559 | return failed_creating(dentry); |
| 560 | |
Seth Forshee | 87243de | 2016-03-09 09:18:07 -0600 | [diff] [blame] | 561 | make_empty_dir_inode(inode); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 562 | inode->i_flags |= S_AUTOMOUNT; |
| 563 | inode->i_private = data; |
| 564 | dentry->d_fsdata = (void *)f; |
Roman Pen | a8f324a | 2016-02-09 11:30:29 +0100 | [diff] [blame] | 565 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 566 | inc_nlink(inode); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 567 | d_instantiate(dentry, inode); |
Roman Pen | a8f324a | 2016-02-09 11:30:29 +0100 | [diff] [blame] | 568 | inc_nlink(d_inode(dentry->d_parent)); |
| 569 | fsnotify_mkdir(d_inode(dentry->d_parent), dentry); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 570 | return end_creating(dentry); |
| 571 | } |
| 572 | EXPORT_SYMBOL(debugfs_create_automount); |
| 573 | |
| 574 | /** |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 575 | * debugfs_create_symlink- create a symbolic link in the debugfs filesystem |
| 576 | * @name: a pointer to a string containing the name of the symbolic link to |
| 577 | * create. |
| 578 | * @parent: a pointer to the parent dentry for this symbolic link. This |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 579 | * should be a directory dentry if set. If this parameter is NULL, |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 580 | * then the symbolic link will be created in the root of the debugfs |
| 581 | * filesystem. |
| 582 | * @target: a pointer to a string containing the path to the target of the |
| 583 | * symbolic link. |
| 584 | * |
| 585 | * This function creates a symbolic link with the given name in debugfs that |
| 586 | * links to the given target path. |
| 587 | * |
| 588 | * This function will return a pointer to a dentry if it succeeds. This |
| 589 | * pointer must be passed to the debugfs_remove() function when the symbolic |
| 590 | * link is to be removed (no automatic cleanup happens if your module is |
| 591 | * unloaded, you are responsible here.) If an error occurs, %NULL will be |
| 592 | * returned. |
| 593 | * |
| 594 | * 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] | 595 | * returned. |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 596 | */ |
| 597 | struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, |
| 598 | const char *target) |
| 599 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 600 | struct dentry *dentry; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 601 | struct inode *inode; |
| 602 | char *link = kstrdup(target, GFP_KERNEL); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 603 | if (!link) |
| 604 | return NULL; |
| 605 | |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 606 | dentry = start_creating(name, parent); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 607 | if (IS_ERR(dentry)) { |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 608 | kfree(link); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 609 | return NULL; |
| 610 | } |
| 611 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 612 | inode = debugfs_get_inode(dentry->d_sb); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 613 | if (unlikely(!inode)) { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 614 | kfree(link); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 615 | return failed_creating(dentry); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 616 | } |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 617 | inode->i_mode = S_IFLNK | S_IRWXUGO; |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame] | 618 | inode->i_op = &simple_symlink_inode_operations; |
| 619 | inode->i_link = link; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 620 | d_instantiate(dentry, inode); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 621 | return end_creating(dentry); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 622 | } |
| 623 | EXPORT_SYMBOL_GPL(debugfs_create_symlink); |
| 624 | |
Nicolai Stange | e9117a5 | 2017-10-31 00:15:48 +0100 | [diff] [blame] | 625 | static void __debugfs_remove_file(struct dentry *dentry, struct dentry *parent) |
| 626 | { |
| 627 | struct debugfs_fsdata *fsd; |
| 628 | |
| 629 | simple_unlink(d_inode(parent), dentry); |
| 630 | d_delete(dentry); |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame^] | 631 | |
| 632 | /* |
| 633 | * Paired with the closing smp_mb() implied by a successful |
| 634 | * cmpxchg() in debugfs_file_get(): either |
| 635 | * debugfs_file_get() must see a dead dentry or we must see a |
| 636 | * debugfs_fsdata instance at ->d_fsdata here (or both). |
| 637 | */ |
| 638 | smp_mb(); |
| 639 | fsd = READ_ONCE(dentry->d_fsdata); |
| 640 | if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) |
| 641 | return; |
Nicolai Stange | e9117a5 | 2017-10-31 00:15:48 +0100 | [diff] [blame] | 642 | if (!refcount_dec_and_test(&fsd->active_users)) |
| 643 | wait_for_completion(&fsd->active_users_drained); |
| 644 | } |
| 645 | |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 646 | static int __debugfs_remove(struct dentry *dentry, struct dentry *parent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | { |
Mathieu Desnoyers | 65c3333 | 2006-11-24 13:50:09 -0500 | [diff] [blame] | 648 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 649 | |
Al Viro | dc3f419 | 2015-05-18 10:10:34 -0400 | [diff] [blame] | 650 | if (simple_positive(dentry)) { |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 651 | dget(dentry); |
Nicolai Stange | e9117a5 | 2017-10-31 00:15:48 +0100 | [diff] [blame] | 652 | if (!d_is_reg(dentry)) { |
| 653 | if (d_is_dir(dentry)) |
| 654 | ret = simple_rmdir(d_inode(parent), dentry); |
| 655 | else |
| 656 | simple_unlink(d_inode(parent), dentry); |
| 657 | if (!ret) |
| 658 | d_delete(dentry); |
| 659 | } else { |
| 660 | __debugfs_remove_file(dentry, parent); |
| 661 | } |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 662 | dput(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | } |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 664 | return ret; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 665 | } |
| 666 | |
| 667 | /** |
| 668 | * debugfs_remove - removes a file or directory from the debugfs filesystem |
| 669 | * @dentry: a pointer to a the dentry of the file or directory to be |
Ulf Magnusson | 398dc4a | 2015-09-07 19:03:15 +0200 | [diff] [blame] | 670 | * removed. If this parameter is NULL or an error value, nothing |
| 671 | * will be done. |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 672 | * |
| 673 | * This function removes a file or directory in debugfs that was previously |
| 674 | * created with a call to another debugfs function (like |
| 675 | * debugfs_create_file() or variants thereof.) |
| 676 | * |
| 677 | * This function is required to be called in order for the file to be |
| 678 | * removed, no automatic cleanup of files will happen when a module is |
| 679 | * removed, you are responsible here. |
| 680 | */ |
| 681 | void debugfs_remove(struct dentry *dentry) |
| 682 | { |
| 683 | struct dentry *parent; |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 684 | int ret; |
| 685 | |
Arend van Spriel | a59d629 | 2012-05-23 15:13:07 +0200 | [diff] [blame] | 686 | if (IS_ERR_OR_NULL(dentry)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 687 | return; |
| 688 | |
| 689 | parent = dentry->d_parent; |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 690 | inode_lock(d_inode(parent)); |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 691 | ret = __debugfs_remove(dentry, parent); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 692 | inode_unlock(d_inode(parent)); |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 693 | if (!ret) |
| 694 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | } |
| 696 | EXPORT_SYMBOL_GPL(debugfs_remove); |
| 697 | |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 698 | /** |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 699 | * debugfs_remove_recursive - recursively removes a directory |
Ulf Magnusson | 398dc4a | 2015-09-07 19:03:15 +0200 | [diff] [blame] | 700 | * @dentry: a pointer to a the dentry of the directory to be removed. If this |
| 701 | * parameter is NULL or an error value, nothing will be done. |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 702 | * |
| 703 | * This function recursively removes a directory tree in debugfs that |
| 704 | * was previously created with a call to another debugfs function |
| 705 | * (like debugfs_create_file() or variants thereof.) |
| 706 | * |
| 707 | * This function is required to be called in order for the file to be |
| 708 | * removed, no automatic cleanup of files will happen when a module is |
| 709 | * removed, you are responsible here. |
| 710 | */ |
| 711 | void debugfs_remove_recursive(struct dentry *dentry) |
| 712 | { |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 713 | struct dentry *child, *parent; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 714 | |
Arend van Spriel | a59d629 | 2012-05-23 15:13:07 +0200 | [diff] [blame] | 715 | if (IS_ERR_OR_NULL(dentry)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 716 | return; |
| 717 | |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 718 | parent = dentry; |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 719 | down: |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 720 | inode_lock(d_inode(parent)); |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 721 | loop: |
| 722 | /* |
| 723 | * The parent->d_subdirs is protected by the d_lock. Outside that |
| 724 | * lock, the child can be unlinked and set to be freed which can |
| 725 | * use the d_u.d_child as the rcu head and corrupt this list. |
| 726 | */ |
| 727 | spin_lock(&parent->d_lock); |
Al Viro | 946e51f | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 728 | list_for_each_entry(child, &parent->d_subdirs, d_child) { |
Al Viro | dc3f419 | 2015-05-18 10:10:34 -0400 | [diff] [blame] | 729 | if (!simple_positive(child)) |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 730 | continue; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 731 | |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 732 | /* perhaps simple_empty(child) makes more sense */ |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 733 | if (!list_empty(&child->d_subdirs)) { |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 734 | spin_unlock(&parent->d_lock); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 735 | inode_unlock(d_inode(parent)); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 736 | parent = child; |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 737 | goto down; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 738 | } |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 739 | |
| 740 | spin_unlock(&parent->d_lock); |
| 741 | |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 742 | if (!__debugfs_remove(child, parent)) |
| 743 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 744 | |
| 745 | /* |
| 746 | * The parent->d_lock protects agaist child from unlinking |
| 747 | * from d_subdirs. When releasing the parent->d_lock we can |
| 748 | * no longer trust that the next pointer is valid. |
| 749 | * Restart the loop. We'll skip this one with the |
Al Viro | dc3f419 | 2015-05-18 10:10:34 -0400 | [diff] [blame] | 750 | * simple_positive() check. |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 751 | */ |
| 752 | goto loop; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 753 | } |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 754 | spin_unlock(&parent->d_lock); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 755 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 756 | inode_unlock(d_inode(parent)); |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 757 | child = parent; |
| 758 | parent = parent->d_parent; |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 759 | inode_lock(d_inode(parent)); |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 760 | |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 761 | if (child != dentry) |
| 762 | /* go up */ |
| 763 | goto loop; |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 764 | |
| 765 | if (!__debugfs_remove(child, parent)) |
| 766 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 767 | inode_unlock(d_inode(parent)); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 768 | } |
| 769 | EXPORT_SYMBOL_GPL(debugfs_remove_recursive); |
| 770 | |
| 771 | /** |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 772 | * debugfs_rename - rename a file/directory in the debugfs filesystem |
| 773 | * @old_dir: a pointer to the parent dentry for the renamed object. This |
| 774 | * should be a directory dentry. |
| 775 | * @old_dentry: dentry of an object to be renamed. |
| 776 | * @new_dir: a pointer to the parent dentry where the object should be |
| 777 | * moved. This should be a directory dentry. |
| 778 | * @new_name: a pointer to a string containing the target name. |
| 779 | * |
| 780 | * This function renames a file/directory in debugfs. The target must not |
| 781 | * exist for rename to succeed. |
| 782 | * |
| 783 | * This function will return a pointer to old_dentry (which is updated to |
| 784 | * reflect renaming) if it succeeds. If an error occurs, %NULL will be |
| 785 | * returned. |
| 786 | * |
| 787 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 788 | * returned. |
| 789 | */ |
| 790 | struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, |
| 791 | struct dentry *new_dir, const char *new_name) |
| 792 | { |
| 793 | int error; |
| 794 | struct dentry *dentry = NULL, *trap; |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 795 | struct name_snapshot old_name; |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 796 | |
| 797 | trap = lock_rename(new_dir, old_dir); |
| 798 | /* Source or destination directories don't exist? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 799 | 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] | 800 | goto exit; |
| 801 | /* Source does not exist, cyclic rename, or mountpoint? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 802 | if (d_really_is_negative(old_dentry) || old_dentry == trap || |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 803 | d_mountpoint(old_dentry)) |
| 804 | goto exit; |
| 805 | dentry = lookup_one_len(new_name, new_dir, strlen(new_name)); |
| 806 | /* Lookup failed, cyclic rename or target exists? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 807 | if (IS_ERR(dentry) || dentry == trap || d_really_is_positive(dentry)) |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 808 | goto exit; |
| 809 | |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 810 | take_dentry_name_snapshot(&old_name, old_dentry); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 811 | |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 812 | error = simple_rename(d_inode(old_dir), old_dentry, d_inode(new_dir), |
Miklos Szeredi | e0e0be8 | 2016-09-27 11:03:57 +0200 | [diff] [blame] | 813 | dentry, 0); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 814 | if (error) { |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 815 | release_dentry_name_snapshot(&old_name); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 816 | goto exit; |
| 817 | } |
| 818 | d_move(old_dentry, dentry); |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 819 | fsnotify_move(d_inode(old_dir), d_inode(new_dir), old_name.name, |
David Howells | e36cb0b | 2015-01-29 12:02:35 +0000 | [diff] [blame] | 820 | d_is_dir(old_dentry), |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 821 | NULL, old_dentry); |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 822 | release_dentry_name_snapshot(&old_name); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 823 | unlock_rename(new_dir, old_dir); |
| 824 | dput(dentry); |
| 825 | return old_dentry; |
| 826 | exit: |
| 827 | if (dentry && !IS_ERR(dentry)) |
| 828 | dput(dentry); |
| 829 | unlock_rename(new_dir, old_dir); |
| 830 | return NULL; |
| 831 | } |
| 832 | EXPORT_SYMBOL_GPL(debugfs_rename); |
| 833 | |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 834 | /** |
| 835 | * debugfs_initialized - Tells whether debugfs has been registered |
| 836 | */ |
| 837 | bool debugfs_initialized(void) |
| 838 | { |
| 839 | return debugfs_registered; |
| 840 | } |
| 841 | EXPORT_SYMBOL_GPL(debugfs_initialized); |
| 842 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 843 | static int __init debugfs_init(void) |
| 844 | { |
| 845 | int retval; |
| 846 | |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 847 | retval = sysfs_create_mount_point(kernel_kobj, "debug"); |
| 848 | if (retval) |
| 849 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | |
| 851 | retval = register_filesystem(&debug_fs_type); |
| 852 | if (retval) |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 853 | sysfs_remove_mount_point(kernel_kobj, "debug"); |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 854 | else |
| 855 | debugfs_registered = true; |
| 856 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | return retval; |
| 858 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 859 | core_initcall(debugfs_init); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 860 | |