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> |
Nicolai Stange | 9fd4dce | 2016-03-22 14:11:13 +0100 | [diff] [blame] | 30 | #include <linux/srcu.h> |
| 31 | |
| 32 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
Kees Cook | 82aceae4 | 2012-08-27 13:32:15 -0700 | [diff] [blame] | 34 | #define DEBUGFS_DEFAULT_MODE 0700 |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 35 | |
Nicolai Stange | 9fd4dce | 2016-03-22 14:11:13 +0100 | [diff] [blame] | 36 | DEFINE_SRCU(debugfs_srcu); |
| 37 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | static struct vfsmount *debugfs_mount; |
| 39 | static int debugfs_mount_count; |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 40 | static bool debugfs_registered; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 42 | static struct inode *debugfs_get_inode(struct super_block *sb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | { |
| 44 | struct inode *inode = new_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 46 | inode->i_ino = get_next_ino(); |
Deepa Dinamani | 1b48b53 | 2016-02-22 07:17:47 -0800 | [diff] [blame] | 47 | inode->i_atime = inode->i_mtime = |
Deepa Dinamani | c2050a4 | 2016-09-14 07:48:06 -0700 | [diff] [blame] | 48 | inode->i_ctime = current_time(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | } |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 50 | return inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | } |
| 52 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 53 | struct debugfs_mount_opts { |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 54 | kuid_t uid; |
| 55 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 56 | umode_t mode; |
| 57 | }; |
| 58 | |
| 59 | enum { |
| 60 | Opt_uid, |
| 61 | Opt_gid, |
| 62 | Opt_mode, |
| 63 | Opt_err |
| 64 | }; |
| 65 | |
| 66 | static const match_table_t tokens = { |
| 67 | {Opt_uid, "uid=%u"}, |
| 68 | {Opt_gid, "gid=%u"}, |
| 69 | {Opt_mode, "mode=%o"}, |
| 70 | {Opt_err, NULL} |
| 71 | }; |
| 72 | |
| 73 | struct debugfs_fs_info { |
| 74 | struct debugfs_mount_opts mount_opts; |
| 75 | }; |
| 76 | |
| 77 | static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts) |
| 78 | { |
| 79 | substring_t args[MAX_OPT_ARGS]; |
| 80 | int option; |
| 81 | int token; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 82 | kuid_t uid; |
| 83 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 84 | char *p; |
| 85 | |
| 86 | opts->mode = DEBUGFS_DEFAULT_MODE; |
| 87 | |
| 88 | while ((p = strsep(&data, ",")) != NULL) { |
| 89 | if (!*p) |
| 90 | continue; |
| 91 | |
| 92 | token = match_token(p, tokens, args); |
| 93 | switch (token) { |
| 94 | case Opt_uid: |
| 95 | if (match_int(&args[0], &option)) |
| 96 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 97 | uid = make_kuid(current_user_ns(), option); |
| 98 | if (!uid_valid(uid)) |
| 99 | return -EINVAL; |
| 100 | opts->uid = uid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 101 | break; |
| 102 | case Opt_gid: |
Dave Reisner | f1688e0 | 2013-01-02 08:54:37 -0500 | [diff] [blame] | 103 | if (match_int(&args[0], &option)) |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 104 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 105 | gid = make_kgid(current_user_ns(), option); |
| 106 | if (!gid_valid(gid)) |
| 107 | return -EINVAL; |
| 108 | opts->gid = gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 109 | break; |
| 110 | case Opt_mode: |
| 111 | if (match_octal(&args[0], &option)) |
| 112 | return -EINVAL; |
| 113 | opts->mode = option & S_IALLUGO; |
| 114 | break; |
| 115 | /* |
| 116 | * We might like to report bad mount options here; |
| 117 | * but traditionally debugfs has ignored all mount options |
| 118 | */ |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | return 0; |
| 123 | } |
| 124 | |
| 125 | static int debugfs_apply_options(struct super_block *sb) |
| 126 | { |
| 127 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 128 | struct inode *inode = d_inode(sb->s_root); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 129 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 130 | |
| 131 | inode->i_mode &= ~S_IALLUGO; |
| 132 | inode->i_mode |= opts->mode; |
| 133 | |
| 134 | inode->i_uid = opts->uid; |
| 135 | inode->i_gid = opts->gid; |
| 136 | |
| 137 | return 0; |
| 138 | } |
| 139 | |
| 140 | static int debugfs_remount(struct super_block *sb, int *flags, char *data) |
| 141 | { |
| 142 | int err; |
| 143 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
| 144 | |
Theodore Ts'o | 02b9984 | 2014-03-13 10:14:33 -0400 | [diff] [blame] | 145 | sync_filesystem(sb); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 146 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 147 | if (err) |
| 148 | goto fail; |
| 149 | |
| 150 | debugfs_apply_options(sb); |
| 151 | |
| 152 | fail: |
| 153 | return err; |
| 154 | } |
| 155 | |
| 156 | static int debugfs_show_options(struct seq_file *m, struct dentry *root) |
| 157 | { |
| 158 | struct debugfs_fs_info *fsi = root->d_sb->s_fs_info; |
| 159 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 160 | |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 161 | if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) |
| 162 | seq_printf(m, ",uid=%u", |
| 163 | from_kuid_munged(&init_user_ns, opts->uid)); |
| 164 | if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) |
| 165 | seq_printf(m, ",gid=%u", |
| 166 | from_kgid_munged(&init_user_ns, opts->gid)); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 167 | if (opts->mode != DEBUGFS_DEFAULT_MODE) |
| 168 | seq_printf(m, ",mode=%o", opts->mode); |
| 169 | |
| 170 | return 0; |
| 171 | } |
| 172 | |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 173 | static void debugfs_evict_inode(struct inode *inode) |
| 174 | { |
| 175 | truncate_inode_pages_final(&inode->i_data); |
| 176 | clear_inode(inode); |
| 177 | if (S_ISLNK(inode->i_mode)) |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame] | 178 | kfree(inode->i_link); |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 179 | } |
| 180 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 181 | static const struct super_operations debugfs_super_operations = { |
| 182 | .statfs = simple_statfs, |
| 183 | .remount_fs = debugfs_remount, |
| 184 | .show_options = debugfs_show_options, |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 185 | .evict_inode = debugfs_evict_inode, |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 186 | }; |
| 187 | |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 188 | static struct vfsmount *debugfs_automount(struct path *path) |
| 189 | { |
| 190 | struct vfsmount *(*f)(void *); |
| 191 | f = (struct vfsmount *(*)(void *))path->dentry->d_fsdata; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 192 | return f(d_inode(path->dentry)->i_private); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 193 | } |
| 194 | |
| 195 | static const struct dentry_operations debugfs_dops = { |
| 196 | .d_delete = always_delete_dentry, |
| 197 | .d_automount = debugfs_automount, |
| 198 | }; |
| 199 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | static int debug_fill_super(struct super_block *sb, void *data, int silent) |
| 201 | { |
| 202 | static struct tree_descr debug_files[] = {{""}}; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 203 | struct debugfs_fs_info *fsi; |
| 204 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 206 | save_mount_options(sb, data); |
| 207 | |
| 208 | fsi = kzalloc(sizeof(struct debugfs_fs_info), GFP_KERNEL); |
| 209 | sb->s_fs_info = fsi; |
| 210 | if (!fsi) { |
| 211 | err = -ENOMEM; |
| 212 | goto fail; |
| 213 | } |
| 214 | |
| 215 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 216 | if (err) |
| 217 | goto fail; |
| 218 | |
| 219 | err = simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); |
| 220 | if (err) |
| 221 | goto fail; |
| 222 | |
| 223 | sb->s_op = &debugfs_super_operations; |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 224 | sb->s_d_op = &debugfs_dops; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 225 | |
| 226 | debugfs_apply_options(sb); |
| 227 | |
| 228 | return 0; |
| 229 | |
| 230 | fail: |
| 231 | kfree(fsi); |
| 232 | sb->s_fs_info = NULL; |
| 233 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | } |
| 235 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 236 | static struct dentry *debug_mount(struct file_system_type *fs_type, |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 237 | int flags, const char *dev_name, |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 238 | void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | { |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 240 | return mount_single(fs_type, flags, data, debug_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | } |
| 242 | |
| 243 | static struct file_system_type debug_fs_type = { |
| 244 | .owner = THIS_MODULE, |
| 245 | .name = "debugfs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 246 | .mount = debug_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | .kill_sb = kill_litter_super, |
| 248 | }; |
Eric W. Biederman | 7f78e03 | 2013-03-02 19:39:14 -0800 | [diff] [blame] | 249 | MODULE_ALIAS_FS("debugfs"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 251 | static struct dentry *start_creating(const char *name, struct dentry *parent) |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 252 | { |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 253 | struct dentry *dentry; |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 254 | int error; |
| 255 | |
| 256 | pr_debug("debugfs: creating file '%s'\n",name); |
| 257 | |
Greg KH | c9e15f2 | 2015-03-30 14:59:15 +0200 | [diff] [blame] | 258 | if (IS_ERR(parent)) |
| 259 | return parent; |
| 260 | |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 261 | error = simple_pin_fs(&debug_fs_type, &debugfs_mount, |
| 262 | &debugfs_mount_count); |
| 263 | if (error) |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 264 | return ERR_PTR(error); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 265 | |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 266 | /* If the parent is not specified, we create it in the root. |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 267 | * 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] | 268 | * block. A pointer to that is in the struct vfsmount that we |
| 269 | * have around. |
| 270 | */ |
| 271 | if (!parent) |
| 272 | parent = debugfs_mount->mnt_root; |
| 273 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 274 | inode_lock(d_inode(parent)); |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 275 | dentry = lookup_one_len(name, parent, strlen(name)); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 276 | if (!IS_ERR(dentry) && d_really_is_positive(dentry)) { |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 277 | dput(dentry); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 278 | dentry = ERR_PTR(-EEXIST); |
| 279 | } |
Daniel Borkmann | 0ee9608 | 2015-11-05 00:01:51 +0100 | [diff] [blame] | 280 | |
| 281 | if (IS_ERR(dentry)) { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 282 | inode_unlock(d_inode(parent)); |
Daniel Borkmann | 0ee9608 | 2015-11-05 00:01:51 +0100 | [diff] [blame] | 283 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
| 284 | } |
| 285 | |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 286 | return dentry; |
| 287 | } |
| 288 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 289 | static struct dentry *failed_creating(struct dentry *dentry) |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 290 | { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 291 | inode_unlock(d_inode(dentry->d_parent)); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 292 | dput(dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 293 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
| 294 | return NULL; |
| 295 | } |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 296 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 297 | static struct dentry *end_creating(struct dentry *dentry) |
| 298 | { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 299 | inode_unlock(d_inode(dentry->d_parent)); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 300 | return dentry; |
| 301 | } |
| 302 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 303 | static struct dentry *__debugfs_create_file(const char *name, umode_t mode, |
| 304 | struct dentry *parent, void *data, |
| 305 | const struct file_operations *proxy_fops, |
| 306 | const struct file_operations *real_fops) |
| 307 | { |
| 308 | struct dentry *dentry; |
| 309 | struct inode *inode; |
| 310 | |
| 311 | if (!(mode & S_IFMT)) |
| 312 | mode |= S_IFREG; |
| 313 | BUG_ON(!S_ISREG(mode)); |
| 314 | dentry = start_creating(name, parent); |
| 315 | |
| 316 | if (IS_ERR(dentry)) |
| 317 | return NULL; |
| 318 | |
| 319 | inode = debugfs_get_inode(dentry->d_sb); |
| 320 | if (unlikely(!inode)) |
| 321 | return failed_creating(dentry); |
| 322 | |
| 323 | inode->i_mode = mode; |
| 324 | inode->i_private = data; |
| 325 | |
| 326 | inode->i_fop = proxy_fops; |
| 327 | dentry->d_fsdata = (void *)real_fops; |
| 328 | |
| 329 | d_instantiate(dentry, inode); |
| 330 | fsnotify_create(d_inode(dentry->d_parent), dentry); |
| 331 | return end_creating(dentry); |
| 332 | } |
| 333 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | /** |
| 335 | * debugfs_create_file - create a file in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | * @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] | 337 | * @mode: the permission that the file should have. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | * @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] | 339 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | * file will be created in the root of the debugfs filesystem. |
| 341 | * @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] | 342 | * on. The inode.i_private pointer will point to this value on |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | * the open() call. |
| 344 | * @fops: a pointer to a struct file_operations that should be used for |
| 345 | * this file. |
| 346 | * |
| 347 | * 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] | 348 | * wide range of flexibility in creating a file, or a directory (if you want |
| 349 | * to create a directory, the debugfs_create_dir() function is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | * recommended to be used instead.) |
| 351 | * |
| 352 | * This function will return a pointer to a dentry if it succeeds. This |
| 353 | * pointer must be passed to the debugfs_remove() function when the file is |
| 354 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 355 | * you are responsible here.) If an error occurs, %NULL will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 357 | * 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] | 358 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | */ |
Al Viro | f4ae40a | 2011-07-24 04:33:43 -0400 | [diff] [blame] | 360 | struct dentry *debugfs_create_file(const char *name, umode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | struct dentry *parent, void *data, |
Arjan van de Ven | 99ac48f | 2006-03-28 01:56:41 -0800 | [diff] [blame] | 362 | const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | { |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 364 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 365 | return __debugfs_create_file(name, mode, parent, data, |
| 366 | fops ? &debugfs_full_proxy_file_operations : |
| 367 | &debugfs_noop_file_operations, |
| 368 | fops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | } |
| 370 | EXPORT_SYMBOL_GPL(debugfs_create_file); |
| 371 | |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 372 | /** |
| 373 | * debugfs_create_file_unsafe - create a file in the debugfs filesystem |
| 374 | * @name: a pointer to a string containing the name of the file to create. |
| 375 | * @mode: the permission that the file should have. |
| 376 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 377 | * directory dentry if set. If this parameter is NULL, then the |
| 378 | * file will be created in the root of the debugfs filesystem. |
| 379 | * @data: a pointer to something that the caller will want to get to later |
| 380 | * on. The inode.i_private pointer will point to this value on |
| 381 | * the open() call. |
| 382 | * @fops: a pointer to a struct file_operations that should be used for |
| 383 | * this file. |
| 384 | * |
| 385 | * debugfs_create_file_unsafe() is completely analogous to |
| 386 | * debugfs_create_file(), the only difference being that the fops |
| 387 | * handed it will not get protected against file removals by the |
| 388 | * debugfs core. |
| 389 | * |
| 390 | * It is your responsibility to protect your struct file_operation |
| 391 | * methods against file removals by means of debugfs_use_file_start() |
| 392 | * and debugfs_use_file_finish(). ->open() is still protected by |
| 393 | * debugfs though. |
| 394 | * |
| 395 | * Any struct file_operations defined by means of |
| 396 | * DEFINE_DEBUGFS_ATTRIBUTE() is protected against file removals and |
| 397 | * thus, may be used here. |
| 398 | */ |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 399 | struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, |
| 400 | struct dentry *parent, void *data, |
| 401 | const struct file_operations *fops) |
| 402 | { |
| 403 | |
| 404 | return __debugfs_create_file(name, mode, parent, data, |
| 405 | fops ? &debugfs_open_proxy_file_operations : |
| 406 | &debugfs_noop_file_operations, |
| 407 | fops); |
| 408 | } |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 409 | EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 410 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | /** |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 412 | * debugfs_create_file_size - create a file in the debugfs filesystem |
| 413 | * @name: a pointer to a string containing the name of the file to create. |
| 414 | * @mode: the permission that the file should have. |
| 415 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 416 | * directory dentry if set. If this parameter is NULL, then the |
| 417 | * file will be created in the root of the debugfs filesystem. |
| 418 | * @data: a pointer to something that the caller will want to get to later |
| 419 | * on. The inode.i_private pointer will point to this value on |
| 420 | * the open() call. |
| 421 | * @fops: a pointer to a struct file_operations that should be used for |
| 422 | * this file. |
| 423 | * @file_size: initial file size |
| 424 | * |
| 425 | * This is the basic "create a file" function for debugfs. It allows for a |
| 426 | * wide range of flexibility in creating a file, or a directory (if you want |
| 427 | * to create a directory, the debugfs_create_dir() function is |
| 428 | * recommended to be used instead.) |
| 429 | * |
| 430 | * This function will return a pointer to a dentry if it succeeds. This |
| 431 | * pointer must be passed to the debugfs_remove() function when the file is |
| 432 | * to be removed (no automatic cleanup happens if your module is unloaded, |
| 433 | * you are responsible here.) If an error occurs, %NULL will be returned. |
| 434 | * |
| 435 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 436 | * returned. |
| 437 | */ |
| 438 | struct dentry *debugfs_create_file_size(const char *name, umode_t mode, |
| 439 | struct dentry *parent, void *data, |
| 440 | const struct file_operations *fops, |
| 441 | loff_t file_size) |
| 442 | { |
| 443 | struct dentry *de = debugfs_create_file(name, mode, parent, data, fops); |
| 444 | |
| 445 | if (de) |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 446 | d_inode(de)->i_size = file_size; |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 447 | return de; |
| 448 | } |
| 449 | EXPORT_SYMBOL_GPL(debugfs_create_file_size); |
| 450 | |
| 451 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | * debugfs_create_dir - create a directory in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | * @name: a pointer to a string containing the name of the directory to |
| 454 | * create. |
| 455 | * @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] | 456 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | * directory will be created in the root of the debugfs filesystem. |
| 458 | * |
| 459 | * This function creates a directory in debugfs with the given name. |
| 460 | * |
| 461 | * This function will return a pointer to a dentry if it succeeds. This |
| 462 | * pointer must be passed to the debugfs_remove() function when the file is |
| 463 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 464 | * you are responsible here.) If an error occurs, %NULL will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 466 | * 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] | 467 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | */ |
| 469 | struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) |
| 470 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 471 | struct dentry *dentry = start_creating(name, parent); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 472 | struct inode *inode; |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 473 | |
| 474 | if (IS_ERR(dentry)) |
| 475 | return NULL; |
| 476 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 477 | inode = debugfs_get_inode(dentry->d_sb); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 478 | if (unlikely(!inode)) |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 479 | return failed_creating(dentry); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 480 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 481 | inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; |
| 482 | inode->i_op = &simple_dir_inode_operations; |
| 483 | inode->i_fop = &simple_dir_operations; |
| 484 | |
| 485 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 486 | inc_nlink(inode); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 487 | d_instantiate(dentry, inode); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 488 | inc_nlink(d_inode(dentry->d_parent)); |
| 489 | fsnotify_mkdir(d_inode(dentry->d_parent), dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 490 | return end_creating(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | } |
| 492 | EXPORT_SYMBOL_GPL(debugfs_create_dir); |
| 493 | |
| 494 | /** |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 495 | * debugfs_create_automount - create automount point in the debugfs filesystem |
| 496 | * @name: a pointer to a string containing the name of the file to create. |
| 497 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 498 | * directory dentry if set. If this parameter is NULL, then the |
| 499 | * file will be created in the root of the debugfs filesystem. |
| 500 | * @f: function to be called when pathname resolution steps on that one. |
| 501 | * @data: opaque argument to pass to f(). |
| 502 | * |
| 503 | * @f should return what ->d_automount() would. |
| 504 | */ |
| 505 | struct dentry *debugfs_create_automount(const char *name, |
| 506 | struct dentry *parent, |
| 507 | struct vfsmount *(*f)(void *), |
| 508 | void *data) |
| 509 | { |
| 510 | struct dentry *dentry = start_creating(name, parent); |
| 511 | struct inode *inode; |
| 512 | |
| 513 | if (IS_ERR(dentry)) |
| 514 | return NULL; |
| 515 | |
| 516 | inode = debugfs_get_inode(dentry->d_sb); |
| 517 | if (unlikely(!inode)) |
| 518 | return failed_creating(dentry); |
| 519 | |
Seth Forshee | 87243de | 2016-03-09 09:18:07 -0600 | [diff] [blame] | 520 | make_empty_dir_inode(inode); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 521 | inode->i_flags |= S_AUTOMOUNT; |
| 522 | inode->i_private = data; |
| 523 | dentry->d_fsdata = (void *)f; |
Roman Pen | a8f324a | 2016-02-09 11:30:29 +0100 | [diff] [blame] | 524 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 525 | inc_nlink(inode); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 526 | d_instantiate(dentry, inode); |
Roman Pen | a8f324a | 2016-02-09 11:30:29 +0100 | [diff] [blame] | 527 | inc_nlink(d_inode(dentry->d_parent)); |
| 528 | fsnotify_mkdir(d_inode(dentry->d_parent), dentry); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 529 | return end_creating(dentry); |
| 530 | } |
| 531 | EXPORT_SYMBOL(debugfs_create_automount); |
| 532 | |
| 533 | /** |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 534 | * debugfs_create_symlink- create a symbolic link in the debugfs filesystem |
| 535 | * @name: a pointer to a string containing the name of the symbolic link to |
| 536 | * create. |
| 537 | * @parent: a pointer to the parent dentry for this symbolic link. This |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 538 | * should be a directory dentry if set. If this parameter is NULL, |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 539 | * then the symbolic link will be created in the root of the debugfs |
| 540 | * filesystem. |
| 541 | * @target: a pointer to a string containing the path to the target of the |
| 542 | * symbolic link. |
| 543 | * |
| 544 | * This function creates a symbolic link with the given name in debugfs that |
| 545 | * links to the given target path. |
| 546 | * |
| 547 | * This function will return a pointer to a dentry if it succeeds. This |
| 548 | * pointer must be passed to the debugfs_remove() function when the symbolic |
| 549 | * link is to be removed (no automatic cleanup happens if your module is |
| 550 | * unloaded, you are responsible here.) If an error occurs, %NULL will be |
| 551 | * returned. |
| 552 | * |
| 553 | * 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] | 554 | * returned. |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 555 | */ |
| 556 | struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, |
| 557 | const char *target) |
| 558 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 559 | struct dentry *dentry; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 560 | struct inode *inode; |
| 561 | char *link = kstrdup(target, GFP_KERNEL); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 562 | if (!link) |
| 563 | return NULL; |
| 564 | |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 565 | dentry = start_creating(name, parent); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 566 | if (IS_ERR(dentry)) { |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 567 | kfree(link); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 568 | return NULL; |
| 569 | } |
| 570 | |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 571 | inode = debugfs_get_inode(dentry->d_sb); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 572 | if (unlikely(!inode)) { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 573 | kfree(link); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 574 | return failed_creating(dentry); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 575 | } |
Al Viro | edac65e | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 576 | inode->i_mode = S_IFLNK | S_IRWXUGO; |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame] | 577 | inode->i_op = &simple_symlink_inode_operations; |
| 578 | inode->i_link = link; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 579 | d_instantiate(dentry, inode); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 580 | return end_creating(dentry); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 581 | } |
| 582 | EXPORT_SYMBOL_GPL(debugfs_create_symlink); |
| 583 | |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 584 | static int __debugfs_remove(struct dentry *dentry, struct dentry *parent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | { |
Mathieu Desnoyers | 65c3333 | 2006-11-24 13:50:09 -0500 | [diff] [blame] | 586 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | |
Al Viro | dc3f419 | 2015-05-18 10:10:34 -0400 | [diff] [blame] | 588 | if (simple_positive(dentry)) { |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 589 | dget(dentry); |
David Howells | 7ceab50 | 2015-03-05 12:46:49 +0000 | [diff] [blame] | 590 | if (d_is_dir(dentry)) |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 591 | ret = simple_rmdir(d_inode(parent), dentry); |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 592 | else |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 593 | simple_unlink(d_inode(parent), dentry); |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 594 | if (!ret) |
| 595 | d_delete(dentry); |
| 596 | dput(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | } |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 598 | return ret; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 599 | } |
| 600 | |
| 601 | /** |
| 602 | * debugfs_remove - removes a file or directory from the debugfs filesystem |
| 603 | * @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] | 604 | * removed. If this parameter is NULL or an error value, nothing |
| 605 | * will be done. |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 606 | * |
| 607 | * This function removes a file or directory in debugfs that was previously |
| 608 | * created with a call to another debugfs function (like |
| 609 | * debugfs_create_file() or variants thereof.) |
| 610 | * |
| 611 | * This function is required to be called in order for the file to be |
| 612 | * removed, no automatic cleanup of files will happen when a module is |
| 613 | * removed, you are responsible here. |
| 614 | */ |
| 615 | void debugfs_remove(struct dentry *dentry) |
| 616 | { |
| 617 | struct dentry *parent; |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 618 | int ret; |
| 619 | |
Arend van Spriel | a59d629 | 2012-05-23 15:13:07 +0200 | [diff] [blame] | 620 | if (IS_ERR_OR_NULL(dentry)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 621 | return; |
| 622 | |
| 623 | parent = dentry->d_parent; |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 624 | inode_lock(d_inode(parent)); |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 625 | ret = __debugfs_remove(dentry, parent); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 626 | inode_unlock(d_inode(parent)); |
Jan Kara | 25d41d8 | 2011-02-07 15:00:27 +0100 | [diff] [blame] | 627 | if (!ret) |
| 628 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 629 | |
Nicolai Stange | 9fd4dce | 2016-03-22 14:11:13 +0100 | [diff] [blame] | 630 | synchronize_srcu(&debugfs_srcu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | } |
| 632 | EXPORT_SYMBOL_GPL(debugfs_remove); |
| 633 | |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 634 | /** |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 635 | * debugfs_remove_recursive - recursively removes a directory |
Ulf Magnusson | 398dc4a | 2015-09-07 19:03:15 +0200 | [diff] [blame] | 636 | * @dentry: a pointer to a the dentry of the directory to be removed. If this |
| 637 | * parameter is NULL or an error value, nothing will be done. |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 638 | * |
| 639 | * This function recursively removes a directory tree in debugfs that |
| 640 | * was previously created with a call to another debugfs function |
| 641 | * (like debugfs_create_file() or variants thereof.) |
| 642 | * |
| 643 | * This function is required to be called in order for the file to be |
| 644 | * removed, no automatic cleanup of files will happen when a module is |
| 645 | * removed, you are responsible here. |
| 646 | */ |
| 647 | void debugfs_remove_recursive(struct dentry *dentry) |
| 648 | { |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 649 | struct dentry *child, *parent; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 650 | |
Arend van Spriel | a59d629 | 2012-05-23 15:13:07 +0200 | [diff] [blame] | 651 | if (IS_ERR_OR_NULL(dentry)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 652 | return; |
| 653 | |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 654 | parent = dentry; |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 655 | down: |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 656 | inode_lock(d_inode(parent)); |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 657 | loop: |
| 658 | /* |
| 659 | * The parent->d_subdirs is protected by the d_lock. Outside that |
| 660 | * lock, the child can be unlinked and set to be freed which can |
| 661 | * use the d_u.d_child as the rcu head and corrupt this list. |
| 662 | */ |
| 663 | spin_lock(&parent->d_lock); |
Al Viro | 946e51f | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 664 | list_for_each_entry(child, &parent->d_subdirs, d_child) { |
Al Viro | dc3f419 | 2015-05-18 10:10:34 -0400 | [diff] [blame] | 665 | if (!simple_positive(child)) |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 666 | continue; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 667 | |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 668 | /* perhaps simple_empty(child) makes more sense */ |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 669 | if (!list_empty(&child->d_subdirs)) { |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 670 | spin_unlock(&parent->d_lock); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 671 | inode_unlock(d_inode(parent)); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 672 | parent = child; |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 673 | goto down; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 674 | } |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 675 | |
| 676 | spin_unlock(&parent->d_lock); |
| 677 | |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 678 | if (!__debugfs_remove(child, parent)) |
| 679 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 680 | |
| 681 | /* |
| 682 | * The parent->d_lock protects agaist child from unlinking |
| 683 | * from d_subdirs. When releasing the parent->d_lock we can |
| 684 | * no longer trust that the next pointer is valid. |
| 685 | * Restart the loop. We'll skip this one with the |
Al Viro | dc3f419 | 2015-05-18 10:10:34 -0400 | [diff] [blame] | 686 | * simple_positive() check. |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 687 | */ |
| 688 | goto loop; |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 689 | } |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 690 | spin_unlock(&parent->d_lock); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 691 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 692 | inode_unlock(d_inode(parent)); |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 693 | child = parent; |
| 694 | parent = parent->d_parent; |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 695 | inode_lock(d_inode(parent)); |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 696 | |
Steven Rostedt | 485d440 | 2014-06-09 14:06:07 -0400 | [diff] [blame] | 697 | if (child != dentry) |
| 698 | /* go up */ |
| 699 | goto loop; |
Oleg Nesterov | 776164c | 2013-07-26 17:12:56 +0200 | [diff] [blame] | 700 | |
| 701 | if (!__debugfs_remove(child, parent)) |
| 702 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 703 | inode_unlock(d_inode(parent)); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 704 | |
Nicolai Stange | 9fd4dce | 2016-03-22 14:11:13 +0100 | [diff] [blame] | 705 | synchronize_srcu(&debugfs_srcu); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 706 | } |
| 707 | EXPORT_SYMBOL_GPL(debugfs_remove_recursive); |
| 708 | |
| 709 | /** |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 710 | * debugfs_rename - rename a file/directory in the debugfs filesystem |
| 711 | * @old_dir: a pointer to the parent dentry for the renamed object. This |
| 712 | * should be a directory dentry. |
| 713 | * @old_dentry: dentry of an object to be renamed. |
| 714 | * @new_dir: a pointer to the parent dentry where the object should be |
| 715 | * moved. This should be a directory dentry. |
| 716 | * @new_name: a pointer to a string containing the target name. |
| 717 | * |
| 718 | * This function renames a file/directory in debugfs. The target must not |
| 719 | * exist for rename to succeed. |
| 720 | * |
| 721 | * This function will return a pointer to old_dentry (which is updated to |
| 722 | * reflect renaming) if it succeeds. If an error occurs, %NULL will be |
| 723 | * returned. |
| 724 | * |
| 725 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 726 | * returned. |
| 727 | */ |
| 728 | struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, |
| 729 | struct dentry *new_dir, const char *new_name) |
| 730 | { |
| 731 | int error; |
| 732 | struct dentry *dentry = NULL, *trap; |
| 733 | const char *old_name; |
| 734 | |
| 735 | trap = lock_rename(new_dir, old_dir); |
| 736 | /* Source or destination directories don't exist? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 737 | 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] | 738 | goto exit; |
| 739 | /* Source does not exist, cyclic rename, or mountpoint? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 740 | if (d_really_is_negative(old_dentry) || old_dentry == trap || |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 741 | d_mountpoint(old_dentry)) |
| 742 | goto exit; |
| 743 | dentry = lookup_one_len(new_name, new_dir, strlen(new_name)); |
| 744 | /* Lookup failed, cyclic rename or target exists? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 745 | if (IS_ERR(dentry) || dentry == trap || d_really_is_positive(dentry)) |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 746 | goto exit; |
| 747 | |
| 748 | old_name = fsnotify_oldname_init(old_dentry->d_name.name); |
| 749 | |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 750 | 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] | 751 | dentry, 0); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 752 | if (error) { |
| 753 | fsnotify_oldname_free(old_name); |
| 754 | goto exit; |
| 755 | } |
| 756 | d_move(old_dentry, dentry); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 757 | fsnotify_move(d_inode(old_dir), d_inode(new_dir), old_name, |
David Howells | e36cb0b | 2015-01-29 12:02:35 +0000 | [diff] [blame] | 758 | d_is_dir(old_dentry), |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 759 | NULL, old_dentry); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 760 | fsnotify_oldname_free(old_name); |
| 761 | unlock_rename(new_dir, old_dir); |
| 762 | dput(dentry); |
| 763 | return old_dentry; |
| 764 | exit: |
| 765 | if (dentry && !IS_ERR(dentry)) |
| 766 | dput(dentry); |
| 767 | unlock_rename(new_dir, old_dir); |
| 768 | return NULL; |
| 769 | } |
| 770 | EXPORT_SYMBOL_GPL(debugfs_rename); |
| 771 | |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 772 | /** |
| 773 | * debugfs_initialized - Tells whether debugfs has been registered |
| 774 | */ |
| 775 | bool debugfs_initialized(void) |
| 776 | { |
| 777 | return debugfs_registered; |
| 778 | } |
| 779 | EXPORT_SYMBOL_GPL(debugfs_initialized); |
| 780 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | static int __init debugfs_init(void) |
| 782 | { |
| 783 | int retval; |
| 784 | |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 785 | retval = sysfs_create_mount_point(kernel_kobj, "debug"); |
| 786 | if (retval) |
| 787 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | |
| 789 | retval = register_filesystem(&debug_fs_type); |
| 790 | if (retval) |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 791 | sysfs_remove_mount_point(kernel_kobj, "debug"); |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 792 | else |
| 793 | debugfs_registered = true; |
| 794 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | return retval; |
| 796 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 797 | core_initcall(debugfs_init); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | |