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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Tejun Heo6d66f5c2007-09-20 17:31:38 +09002 * fs/sysfs/dir.c - sysfs core and dir operation implementation
3 *
4 * Copyright (c) 2001-3 Patrick Mochel
5 * Copyright (c) 2007 SUSE Linux Products GmbH
6 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
7 *
8 * This file is released under the GPLv2.
9 *
10 * Please see Documentation/filesystems/sysfs.txt for more information.
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 */
12
13#undef DEBUG
14
15#include <linux/fs.h>
16#include <linux/mount.h>
17#include <linux/module.h>
18#include <linux/kobject.h>
Christoph Hellwig5f45f1a2005-06-23 00:09:12 -070019#include <linux/namei.h>
Tejun Heo2b611bb2007-06-14 03:45:13 +090020#include <linux/idr.h>
Tejun Heo8619f972007-06-14 03:45:18 +090021#include <linux/completion.h>
Dave Young869512a2007-07-26 14:53:53 +000022#include <linux/mutex.h>
Robert P. J. Dayc6f87732008-03-13 22:41:52 -040023#include <linux/slab.h>
Eric W. Biederman4c3da222009-11-04 02:50:06 -080024#include <linux/security.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include "sysfs.h"
26
Tejun Heo3007e992007-06-14 04:27:23 +090027DEFINE_MUTEX(sysfs_mutex);
Roel Kluinf7a75f02007-10-16 23:30:25 -070028DEFINE_SPINLOCK(sysfs_assoc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
Roel Kluinf7a75f02007-10-16 23:30:25 -070030static DEFINE_SPINLOCK(sysfs_ino_lock);
Tejun Heo2b611bb2007-06-14 03:45:13 +090031static DEFINE_IDA(sysfs_ino_ida);
32
Tejun Heob6b4a432007-06-14 03:45:18 +090033/**
Tejun Heo0c73f182007-06-14 03:45:18 +090034 * sysfs_link_sibling - link sysfs_dirent into sibling list
35 * @sd: sysfs_dirent of interest
36 *
37 * Link @sd into its sibling list which starts from
Tejun Heobc747f32007-09-20 16:05:12 +090038 * sd->s_parent->s_dir.children.
Tejun Heo0c73f182007-06-14 03:45:18 +090039 *
40 * Locking:
Tejun Heo3007e992007-06-14 04:27:23 +090041 * mutex_lock(sysfs_mutex)
Tejun Heo0c73f182007-06-14 03:45:18 +090042 */
Tejun Heo41fc1c22007-08-02 21:38:03 +090043static void sysfs_link_sibling(struct sysfs_dirent *sd)
Tejun Heo0c73f182007-06-14 03:45:18 +090044{
45 struct sysfs_dirent *parent_sd = sd->s_parent;
Eric W. Biederman3efa65b2007-08-20 21:36:30 +090046 struct sysfs_dirent **pos;
Tejun Heo0c73f182007-06-14 03:45:18 +090047
48 BUG_ON(sd->s_sibling);
Eric W. Biederman3efa65b2007-08-20 21:36:30 +090049
50 /* Store directory entries in order by ino. This allows
51 * readdir to properly restart without having to add a
Tejun Heobc747f32007-09-20 16:05:12 +090052 * cursor into the s_dir.children list.
Eric W. Biederman3efa65b2007-08-20 21:36:30 +090053 */
Tejun Heobc747f32007-09-20 16:05:12 +090054 for (pos = &parent_sd->s_dir.children; *pos; pos = &(*pos)->s_sibling) {
Eric W. Biederman3efa65b2007-08-20 21:36:30 +090055 if (sd->s_ino < (*pos)->s_ino)
56 break;
57 }
58 sd->s_sibling = *pos;
59 *pos = sd;
Tejun Heo0c73f182007-06-14 03:45:18 +090060}
61
62/**
63 * sysfs_unlink_sibling - unlink sysfs_dirent from sibling list
64 * @sd: sysfs_dirent of interest
65 *
66 * Unlink @sd from its sibling list which starts from
Tejun Heobc747f32007-09-20 16:05:12 +090067 * sd->s_parent->s_dir.children.
Tejun Heo0c73f182007-06-14 03:45:18 +090068 *
69 * Locking:
Tejun Heo3007e992007-06-14 04:27:23 +090070 * mutex_lock(sysfs_mutex)
Tejun Heo0c73f182007-06-14 03:45:18 +090071 */
Tejun Heo41fc1c22007-08-02 21:38:03 +090072static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
Tejun Heo0c73f182007-06-14 03:45:18 +090073{
74 struct sysfs_dirent **pos;
75
Tejun Heobc747f32007-09-20 16:05:12 +090076 for (pos = &sd->s_parent->s_dir.children; *pos;
77 pos = &(*pos)->s_sibling) {
Tejun Heo0c73f182007-06-14 03:45:18 +090078 if (*pos == sd) {
79 *pos = sd->s_sibling;
80 sd->s_sibling = NULL;
81 break;
82 }
83 }
84}
85
86/**
Tejun Heob6b4a432007-06-14 03:45:18 +090087 * sysfs_get_active - get an active reference to sysfs_dirent
88 * @sd: sysfs_dirent to get an active reference to
89 *
90 * Get an active reference of @sd. This function is noop if @sd
91 * is NULL.
92 *
93 * RETURNS:
94 * Pointer to @sd on success, NULL on failure.
95 */
Eric W. Biedermane72ceb82010-02-11 15:18:38 -080096struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
Tejun Heob6b4a432007-06-14 03:45:18 +090097{
Tejun Heo8619f972007-06-14 03:45:18 +090098 if (unlikely(!sd))
99 return NULL;
100
101 while (1) {
102 int v, t;
103
104 v = atomic_read(&sd->s_active);
105 if (unlikely(v < 0))
106 return NULL;
107
108 t = atomic_cmpxchg(&sd->s_active, v, v + 1);
Eric W. Biederman846f9972010-01-02 13:37:12 -0800109 if (likely(t == v)) {
110 rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
Tejun Heo8619f972007-06-14 03:45:18 +0900111 return sd;
Eric W. Biederman846f9972010-01-02 13:37:12 -0800112 }
Tejun Heo8619f972007-06-14 03:45:18 +0900113 if (t < 0)
114 return NULL;
115
116 cpu_relax();
Tejun Heob6b4a432007-06-14 03:45:18 +0900117 }
Tejun Heob6b4a432007-06-14 03:45:18 +0900118}
119
120/**
121 * sysfs_put_active - put an active reference to sysfs_dirent
122 * @sd: sysfs_dirent to put an active reference to
123 *
124 * Put an active reference to @sd. This function is noop if @sd
125 * is NULL.
126 */
Eric W. Biedermane72ceb82010-02-11 15:18:38 -0800127void sysfs_put_active(struct sysfs_dirent *sd)
Tejun Heob6b4a432007-06-14 03:45:18 +0900128{
Tejun Heo8619f972007-06-14 03:45:18 +0900129 struct completion *cmpl;
130 int v;
131
132 if (unlikely(!sd))
133 return;
134
Eric W. Biederman846f9972010-01-02 13:37:12 -0800135 rwsem_release(&sd->dep_map, 1, _RET_IP_);
Tejun Heo8619f972007-06-14 03:45:18 +0900136 v = atomic_dec_return(&sd->s_active);
137 if (likely(v != SD_DEACTIVATED_BIAS))
138 return;
139
140 /* atomic_dec_return() is a mb(), we'll always see the updated
Tejun Heo0c73f182007-06-14 03:45:18 +0900141 * sd->s_sibling.
Tejun Heo8619f972007-06-14 03:45:18 +0900142 */
Tejun Heo0c73f182007-06-14 03:45:18 +0900143 cmpl = (void *)sd->s_sibling;
Tejun Heo8619f972007-06-14 03:45:18 +0900144 complete(cmpl);
Tejun Heob6b4a432007-06-14 03:45:18 +0900145}
146
147/**
Tejun Heob6b4a432007-06-14 03:45:18 +0900148 * sysfs_deactivate - deactivate sysfs_dirent
149 * @sd: sysfs_dirent to deactivate
150 *
Tejun Heo8619f972007-06-14 03:45:18 +0900151 * Deny new active references and drain existing ones.
Tejun Heob6b4a432007-06-14 03:45:18 +0900152 */
Tejun Heofb6896d2007-06-14 04:27:24 +0900153static void sysfs_deactivate(struct sysfs_dirent *sd)
Tejun Heob6b4a432007-06-14 03:45:18 +0900154{
Tejun Heo8619f972007-06-14 03:45:18 +0900155 DECLARE_COMPLETION_ONSTACK(wait);
156 int v;
Tejun Heob6b4a432007-06-14 03:45:18 +0900157
Tejun Heo380e6fb2007-06-14 04:27:22 +0900158 BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED));
Eric W. Biedermana2db6842010-02-11 15:20:00 -0800159
160 if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF))
161 return;
162
Tejun Heo0c73f182007-06-14 03:45:18 +0900163 sd->s_sibling = (void *)&wait;
Tejun Heo8619f972007-06-14 03:45:18 +0900164
Eric W. Biederman846f9972010-01-02 13:37:12 -0800165 rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_);
Tejun Heo8619f972007-06-14 03:45:18 +0900166 /* atomic_add_return() is a mb(), put_active() will always see
Tejun Heo0c73f182007-06-14 03:45:18 +0900167 * the updated sd->s_sibling.
Tejun Heob6b4a432007-06-14 03:45:18 +0900168 */
Tejun Heo8619f972007-06-14 03:45:18 +0900169 v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
170
Eric W. Biederman846f9972010-01-02 13:37:12 -0800171 if (v != SD_DEACTIVATED_BIAS) {
172 lock_contended(&sd->dep_map, _RET_IP_);
Tejun Heo8619f972007-06-14 03:45:18 +0900173 wait_for_completion(&wait);
Eric W. Biederman846f9972010-01-02 13:37:12 -0800174 }
Tejun Heo8619f972007-06-14 03:45:18 +0900175
Tejun Heo0c73f182007-06-14 03:45:18 +0900176 sd->s_sibling = NULL;
Eric W. Biederman846f9972010-01-02 13:37:12 -0800177
178 lock_acquired(&sd->dep_map, _RET_IP_);
179 rwsem_release(&sd->dep_map, 1, _RET_IP_);
Tejun Heob6b4a432007-06-14 03:45:18 +0900180}
181
Tejun Heo42b37df2007-06-14 03:45:17 +0900182static int sysfs_alloc_ino(ino_t *pino)
Tejun Heo2b611bb2007-06-14 03:45:13 +0900183{
184 int ino, rc;
185
186 retry:
187 spin_lock(&sysfs_ino_lock);
188 rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino);
189 spin_unlock(&sysfs_ino_lock);
190
191 if (rc == -EAGAIN) {
192 if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL))
193 goto retry;
194 rc = -ENOMEM;
195 }
196
197 *pino = ino;
198 return rc;
199}
200
201static void sysfs_free_ino(ino_t ino)
202{
203 spin_lock(&sysfs_ino_lock);
204 ida_remove(&sysfs_ino_ida, ino);
205 spin_unlock(&sysfs_ino_lock);
206}
207
Tejun Heofa7f9122007-06-14 03:45:13 +0900208void release_sysfs_dirent(struct sysfs_dirent * sd)
209{
Tejun Heo13b30862007-06-14 03:45:14 +0900210 struct sysfs_dirent *parent_sd;
211
212 repeat:
Tejun Heo3007e992007-06-14 04:27:23 +0900213 /* Moving/renaming is always done while holding reference.
214 * sd->s_parent won't change beneath us.
215 */
Tejun Heo13b30862007-06-14 03:45:14 +0900216 parent_sd = sd->s_parent;
217
Tejun Heob402d722007-06-14 04:27:21 +0900218 if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
Tejun Heob1fc3d62007-09-20 16:05:11 +0900219 sysfs_put(sd->s_symlink.target_sd);
Tejun Heob402d722007-06-14 04:27:21 +0900220 if (sysfs_type(sd) & SYSFS_COPY_NAME)
Tejun Heo0c096b52007-06-14 03:45:15 +0900221 kfree(sd->s_name);
Eric W. Biederman4c3da222009-11-04 02:50:06 -0800222 if (sd->s_iattr && sd->s_iattr->ia_secdata)
223 security_release_secctx(sd->s_iattr->ia_secdata,
224 sd->s_iattr->ia_secdata_len);
Tejun Heofa7f9122007-06-14 03:45:13 +0900225 kfree(sd->s_iattr);
Tejun Heo2b611bb2007-06-14 03:45:13 +0900226 sysfs_free_ino(sd->s_ino);
Tejun Heofa7f9122007-06-14 03:45:13 +0900227 kmem_cache_free(sysfs_dir_cachep, sd);
Tejun Heo13b30862007-06-14 03:45:14 +0900228
229 sd = parent_sd;
230 if (sd && atomic_dec_and_test(&sd->s_count))
231 goto repeat;
Tejun Heofa7f9122007-06-14 03:45:13 +0900232}
233
Eric W. Biedermane8f077c2009-11-07 23:27:01 -0800234static int sysfs_dentry_delete(struct dentry *dentry)
235{
236 struct sysfs_dirent *sd = dentry->d_fsdata;
237 return !!(sd->s_flags & SYSFS_FLAG_REMOVED);
238}
239
240static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
241{
242 struct sysfs_dirent *sd = dentry->d_fsdata;
243 int is_dir;
244
245 mutex_lock(&sysfs_mutex);
246
247 /* The sysfs dirent has been deleted */
248 if (sd->s_flags & SYSFS_FLAG_REMOVED)
249 goto out_bad;
250
Eric W. Biederman832b6af2009-11-20 16:08:56 -0800251 /* The sysfs dirent has been moved? */
252 if (dentry->d_parent->d_fsdata != sd->s_parent)
253 goto out_bad;
254
255 /* The sysfs dirent has been renamed */
256 if (strcmp(dentry->d_name.name, sd->s_name) != 0)
257 goto out_bad;
258
Eric W. Biedermane8f077c2009-11-07 23:27:01 -0800259 mutex_unlock(&sysfs_mutex);
260out_valid:
261 return 1;
262out_bad:
263 /* Remove the dentry from the dcache hashes.
264 * If this is a deleted dentry we use d_drop instead of d_delete
265 * so sysfs doesn't need to cope with negative dentries.
Eric W. Biederman832b6af2009-11-20 16:08:56 -0800266 *
267 * If this is a dentry that has simply been renamed we
268 * use d_drop to remove it from the dcache lookup on its
269 * old parent. If this dentry persists later when a lookup
270 * is performed at its new name the dentry will be readded
271 * to the dcache hashes.
Eric W. Biedermane8f077c2009-11-07 23:27:01 -0800272 */
273 is_dir = (sysfs_type(sd) == SYSFS_DIR);
274 mutex_unlock(&sysfs_mutex);
275 if (is_dir) {
276 /* If we have submounts we must allow the vfs caches
277 * to lie about the state of the filesystem to prevent
278 * leaks and other nasty things.
279 */
280 if (have_submounts(dentry))
281 goto out_valid;
282 shrink_dcache_parent(dentry);
283 }
284 d_drop(dentry);
285 return 0;
286}
287
Eric W. Biederman28a027c2009-11-07 23:27:00 -0800288static void sysfs_dentry_iput(struct dentry *dentry, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289{
290 struct sysfs_dirent * sd = dentry->d_fsdata;
291
Eric W. Biederman5a26b792007-08-20 21:36:30 +0900292 sysfs_put(sd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 iput(inode);
294}
295
Al Viroee1ec322009-02-20 06:01:46 +0000296static const struct dentry_operations sysfs_dentry_ops = {
Eric W. Biedermane8f077c2009-11-07 23:27:01 -0800297 .d_revalidate = sysfs_dentry_revalidate,
298 .d_delete = sysfs_dentry_delete,
Eric W. Biederman28a027c2009-11-07 23:27:00 -0800299 .d_iput = sysfs_dentry_iput,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300};
301
Tejun Heo3e519032007-06-14 03:45:15 +0900302struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303{
Tejun Heo0c096b52007-06-14 03:45:15 +0900304 char *dup_name = NULL;
Akinobu Mita01da2422007-07-14 11:03:35 +0900305 struct sysfs_dirent *sd;
Tejun Heo0c096b52007-06-14 03:45:15 +0900306
307 if (type & SYSFS_COPY_NAME) {
308 name = dup_name = kstrdup(name, GFP_KERNEL);
309 if (!name)
Akinobu Mita01da2422007-07-14 11:03:35 +0900310 return NULL;
Tejun Heo0c096b52007-06-14 03:45:15 +0900311 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Robert P. J. Dayc3762222007-02-10 01:45:03 -0800313 sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 if (!sd)
Akinobu Mita01da2422007-07-14 11:03:35 +0900315 goto err_out1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
Tejun Heo0c096b52007-06-14 03:45:15 +0900317 if (sysfs_alloc_ino(&sd->s_ino))
Akinobu Mita01da2422007-07-14 11:03:35 +0900318 goto err_out2;
Tejun Heo2b611bb2007-06-14 03:45:13 +0900319
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 atomic_set(&sd->s_count, 1);
Tejun Heo8619f972007-06-14 03:45:18 +0900321 atomic_set(&sd->s_active, 0);
Tejun Heoa26cd722007-06-14 03:45:14 +0900322
Tejun Heo0c096b52007-06-14 03:45:15 +0900323 sd->s_name = name;
Tejun Heoa26cd722007-06-14 03:45:14 +0900324 sd->s_mode = mode;
Tejun Heob402d722007-06-14 04:27:21 +0900325 sd->s_flags = type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326
327 return sd;
Tejun Heo0c096b52007-06-14 03:45:15 +0900328
Akinobu Mita01da2422007-07-14 11:03:35 +0900329 err_out2:
Tejun Heo0c096b52007-06-14 03:45:15 +0900330 kmem_cache_free(sysfs_dir_cachep, sd);
Akinobu Mita01da2422007-07-14 11:03:35 +0900331 err_out1:
332 kfree(dup_name);
Tejun Heo0c096b52007-06-14 03:45:15 +0900333 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334}
335
Tejun Heo3007e992007-06-14 04:27:23 +0900336/**
Tejun Heofb6896d2007-06-14 04:27:24 +0900337 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
338 * @acxt: pointer to sysfs_addrm_cxt to be used
339 * @parent_sd: parent sysfs_dirent
Tejun Heo3007e992007-06-14 04:27:23 +0900340 *
Tejun Heofb6896d2007-06-14 04:27:24 +0900341 * This function is called when the caller is about to add or
342 * remove sysfs_dirent under @parent_sd. This function acquires
Eric W. Biedermana16bbc32009-11-20 16:08:55 -0800343 * sysfs_mutex. @acxt is used to keep and pass context to
Tejun Heofb6896d2007-06-14 04:27:24 +0900344 * other addrm functions.
Tejun Heo3007e992007-06-14 04:27:23 +0900345 *
346 * LOCKING:
Tejun Heofb6896d2007-06-14 04:27:24 +0900347 * Kernel thread context (may sleep). sysfs_mutex is locked on
Eric W. Biedermana16bbc32009-11-20 16:08:55 -0800348 * return.
Tejun Heo3007e992007-06-14 04:27:23 +0900349 */
Tejun Heofb6896d2007-06-14 04:27:24 +0900350void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
351 struct sysfs_dirent *parent_sd)
Eric W. Biedermanb592fcf2007-01-24 12:35:52 -0700352{
Tejun Heofb6896d2007-06-14 04:27:24 +0900353 memset(acxt, 0, sizeof(*acxt));
354 acxt->parent_sd = parent_sd;
355
Tejun Heofb6896d2007-06-14 04:27:24 +0900356 mutex_lock(&sysfs_mutex);
Tejun Heofb6896d2007-06-14 04:27:24 +0900357}
358
359/**
Cornelia Huck36ce6da2008-06-10 11:09:08 +0200360 * __sysfs_add_one - add sysfs_dirent to parent without warning
361 * @acxt: addrm context to use
362 * @sd: sysfs_dirent to be added
363 *
364 * Get @acxt->parent_sd and set sd->s_parent to it and increment
365 * nlink of parent inode if @sd is a directory and link into the
366 * children list of the parent.
367 *
368 * This function should be called between calls to
369 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
370 * passed the same @acxt as passed to sysfs_addrm_start().
371 *
372 * LOCKING:
373 * Determined by sysfs_addrm_start().
374 *
375 * RETURNS:
376 * 0 on success, -EEXIST if entry with the given name already
377 * exists.
378 */
379int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
380{
Eric W. Biederman6b0bfe92009-11-20 16:08:51 -0800381 struct sysfs_inode_attrs *ps_iattr;
382
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700383 if (sysfs_find_dirent(acxt->parent_sd, sd->s_ns, sd->s_name))
Cornelia Huck36ce6da2008-06-10 11:09:08 +0200384 return -EEXIST;
385
386 sd->s_parent = sysfs_get(acxt->parent_sd);
387
Cornelia Huck36ce6da2008-06-10 11:09:08 +0200388 sysfs_link_sibling(sd);
389
Eric W. Biederman6b0bfe92009-11-20 16:08:51 -0800390 /* Update timestamps on the parent */
391 ps_iattr = acxt->parent_sd->s_iattr;
392 if (ps_iattr) {
393 struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
394 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
395 }
396
Cornelia Huck36ce6da2008-06-10 11:09:08 +0200397 return 0;
398}
399
400/**
Alex Chiang425cb022009-02-12 10:56:59 -0700401 * sysfs_pathname - return full path to sysfs dirent
402 * @sd: sysfs_dirent whose path we want
403 * @path: caller allocated buffer
404 *
405 * Gives the name "/" to the sysfs_root entry; any path returned
406 * is relative to wherever sysfs is mounted.
407 *
408 * XXX: does no error checking on @path size
409 */
410static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
411{
412 if (sd->s_parent) {
413 sysfs_pathname(sd->s_parent, path);
414 strcat(path, "/");
415 }
416 strcat(path, sd->s_name);
417 return path;
418}
419
420/**
Tejun Heofb6896d2007-06-14 04:27:24 +0900421 * sysfs_add_one - add sysfs_dirent to parent
422 * @acxt: addrm context to use
423 * @sd: sysfs_dirent to be added
424 *
425 * Get @acxt->parent_sd and set sd->s_parent to it and increment
Tejun Heo181b2e42007-09-20 16:05:09 +0900426 * nlink of parent inode if @sd is a directory and link into the
427 * children list of the parent.
Tejun Heofb6896d2007-06-14 04:27:24 +0900428 *
429 * This function should be called between calls to
430 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
431 * passed the same @acxt as passed to sysfs_addrm_start().
432 *
433 * LOCKING:
434 * Determined by sysfs_addrm_start().
Tejun Heo23dc2792007-08-02 21:38:03 +0900435 *
436 * RETURNS:
437 * 0 on success, -EEXIST if entry with the given name already
438 * exists.
Tejun Heofb6896d2007-06-14 04:27:24 +0900439 */
Tejun Heo23dc2792007-08-02 21:38:03 +0900440int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
Tejun Heofb6896d2007-06-14 04:27:24 +0900441{
Cornelia Huck36ce6da2008-06-10 11:09:08 +0200442 int ret;
Tejun Heo23dc2792007-08-02 21:38:03 +0900443
Cornelia Huck36ce6da2008-06-10 11:09:08 +0200444 ret = __sysfs_add_one(acxt, sd);
Alex Chiang425cb022009-02-12 10:56:59 -0700445 if (ret == -EEXIST) {
446 char *path = kzalloc(PATH_MAX, GFP_KERNEL);
447 WARN(1, KERN_WARNING
448 "sysfs: cannot create duplicate filename '%s'\n",
449 (path == NULL) ? sd->s_name :
450 strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"),
451 sd->s_name));
452 kfree(path);
453 }
454
Cornelia Huck36ce6da2008-06-10 11:09:08 +0200455 return ret;
Tejun Heofb6896d2007-06-14 04:27:24 +0900456}
457
458/**
459 * sysfs_remove_one - remove sysfs_dirent from parent
460 * @acxt: addrm context to use
Jean Delvare9fd5b1c2008-01-08 18:11:24 +0100461 * @sd: sysfs_dirent to be removed
Tejun Heofb6896d2007-06-14 04:27:24 +0900462 *
463 * Mark @sd removed and drop nlink of parent inode if @sd is a
Tejun Heo181b2e42007-09-20 16:05:09 +0900464 * directory. @sd is unlinked from the children list.
Tejun Heofb6896d2007-06-14 04:27:24 +0900465 *
466 * This function should be called between calls to
467 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
468 * passed the same @acxt as passed to sysfs_addrm_start().
469 *
470 * LOCKING:
471 * Determined by sysfs_addrm_start().
472 */
473void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
474{
Eric W. Biederman6b0bfe92009-11-20 16:08:51 -0800475 struct sysfs_inode_attrs *ps_iattr;
476
Tejun Heo41fc1c22007-08-02 21:38:03 +0900477 BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
478
479 sysfs_unlink_sibling(sd);
Tejun Heofb6896d2007-06-14 04:27:24 +0900480
Eric W. Biederman6b0bfe92009-11-20 16:08:51 -0800481 /* Update timestamps on the parent */
482 ps_iattr = acxt->parent_sd->s_iattr;
483 if (ps_iattr) {
484 struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
485 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
486 }
487
Tejun Heofb6896d2007-06-14 04:27:24 +0900488 sd->s_flags |= SYSFS_FLAG_REMOVED;
489 sd->s_sibling = acxt->removed;
490 acxt->removed = sd;
Tejun Heoa0edd7c2007-06-14 04:27:24 +0900491}
492
493/**
Tejun Heofb6896d2007-06-14 04:27:24 +0900494 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
495 * @acxt: addrm context to finish up
496 *
497 * Finish up sysfs_dirent add/remove. Resources acquired by
498 * sysfs_addrm_start() are released and removed sysfs_dirents are
Eric W. Biedermana16bbc32009-11-20 16:08:55 -0800499 * cleaned up.
Tejun Heofb6896d2007-06-14 04:27:24 +0900500 *
501 * LOCKING:
Eric W. Biedermana16bbc32009-11-20 16:08:55 -0800502 * sysfs_mutex is released.
Tejun Heofb6896d2007-06-14 04:27:24 +0900503 */
Tejun Heo990e53f2007-08-02 21:38:03 +0900504void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
Tejun Heofb6896d2007-06-14 04:27:24 +0900505{
506 /* release resources acquired by sysfs_addrm_start() */
507 mutex_unlock(&sysfs_mutex);
Tejun Heofb6896d2007-06-14 04:27:24 +0900508
509 /* kill removed sysfs_dirents */
510 while (acxt->removed) {
511 struct sysfs_dirent *sd = acxt->removed;
512
513 acxt->removed = sd->s_sibling;
514 sd->s_sibling = NULL;
515
Tejun Heofb6896d2007-06-14 04:27:24 +0900516 sysfs_deactivate(sd);
Eric W. Biedermane0edd3c2009-03-04 11:57:20 -0800517 unmap_bin_file(sd);
Tejun Heofb6896d2007-06-14 04:27:24 +0900518 sysfs_put(sd);
519 }
Eric W. Biedermanb592fcf2007-01-24 12:35:52 -0700520}
521
Tejun Heof0b0af42007-06-14 04:27:22 +0900522/**
523 * sysfs_find_dirent - find sysfs_dirent with the given name
524 * @parent_sd: sysfs_dirent to search under
525 * @name: name to look for
Maneesh Sonic5168652006-03-09 19:40:14 +0530526 *
Tejun Heof0b0af42007-06-14 04:27:22 +0900527 * Look for sysfs_dirent with name @name under @parent_sd.
Maneesh Sonic5168652006-03-09 19:40:14 +0530528 *
Tejun Heof0b0af42007-06-14 04:27:22 +0900529 * LOCKING:
Tejun Heo3007e992007-06-14 04:27:23 +0900530 * mutex_lock(sysfs_mutex)
Tejun Heof0b0af42007-06-14 04:27:22 +0900531 *
532 * RETURNS:
533 * Pointer to sysfs_dirent if found, NULL if not.
Maneesh Sonic5168652006-03-09 19:40:14 +0530534 */
Tejun Heof0b0af42007-06-14 04:27:22 +0900535struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700536 const void *ns,
Tejun Heof0b0af42007-06-14 04:27:22 +0900537 const unsigned char *name)
Maneesh Sonic5168652006-03-09 19:40:14 +0530538{
Tejun Heof0b0af42007-06-14 04:27:22 +0900539 struct sysfs_dirent *sd;
Maneesh Sonic5168652006-03-09 19:40:14 +0530540
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700541 for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling) {
Eric W. Biedermanaf10ec72010-03-30 11:31:27 -0700542 if (ns && sd->s_ns && (sd->s_ns != ns))
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700543 continue;
Eric W. Biederman3efa65b2007-08-20 21:36:30 +0900544 if (!strcmp(sd->s_name, name))
Tejun Heof0b0af42007-06-14 04:27:22 +0900545 return sd;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700546 }
Tejun Heof0b0af42007-06-14 04:27:22 +0900547 return NULL;
548}
Maneesh Sonic5168652006-03-09 19:40:14 +0530549
Tejun Heof0b0af42007-06-14 04:27:22 +0900550/**
551 * sysfs_get_dirent - find and get sysfs_dirent with the given name
552 * @parent_sd: sysfs_dirent to search under
553 * @name: name to look for
554 *
555 * Look for sysfs_dirent with name @name under @parent_sd and get
556 * it if found.
557 *
558 * LOCKING:
Tejun Heo3007e992007-06-14 04:27:23 +0900559 * Kernel thread context (may sleep). Grabs sysfs_mutex.
Tejun Heof0b0af42007-06-14 04:27:22 +0900560 *
561 * RETURNS:
562 * Pointer to sysfs_dirent if found, NULL if not.
563 */
564struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700565 const void *ns,
Tejun Heof0b0af42007-06-14 04:27:22 +0900566 const unsigned char *name)
567{
568 struct sysfs_dirent *sd;
569
Tejun Heo3007e992007-06-14 04:27:23 +0900570 mutex_lock(&sysfs_mutex);
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700571 sd = sysfs_find_dirent(parent_sd, ns, name);
Tejun Heof0b0af42007-06-14 04:27:22 +0900572 sysfs_get(sd);
Tejun Heo3007e992007-06-14 04:27:23 +0900573 mutex_unlock(&sysfs_mutex);
Tejun Heof0b0af42007-06-14 04:27:22 +0900574
575 return sd;
Maneesh Sonic5168652006-03-09 19:40:14 +0530576}
Neil Brownf1282c82008-07-16 08:58:04 +1000577EXPORT_SYMBOL_GPL(sysfs_get_dirent);
Maneesh Sonic5168652006-03-09 19:40:14 +0530578
Tejun Heo608e2662007-06-14 04:27:22 +0900579static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700580 enum kobj_ns_type type, const void *ns, const char *name,
581 struct sysfs_dirent **p_sd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
Tejun Heo51225032007-06-14 04:27:25 +0900584 struct sysfs_addrm_cxt acxt;
Tejun Heodfeb9fb2007-06-14 03:45:14 +0900585 struct sysfs_dirent *sd;
Tejun Heo23dc2792007-08-02 21:38:03 +0900586 int rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
Tejun Heofc9f54b2007-06-14 03:45:17 +0900588 /* allocate */
Tejun Heo3e519032007-06-14 03:45:15 +0900589 sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
Tejun Heoa26cd722007-06-14 03:45:14 +0900590 if (!sd)
Tejun Heo51225032007-06-14 04:27:25 +0900591 return -ENOMEM;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700592
593 sd->s_flags |= (type << SYSFS_NS_TYPE_SHIFT);
594 sd->s_ns = ns;
Tejun Heob1fc3d62007-09-20 16:05:11 +0900595 sd->s_dir.kobj = kobj;
Tejun Heodfeb9fb2007-06-14 03:45:14 +0900596
Tejun Heo51225032007-06-14 04:27:25 +0900597 /* link in */
598 sysfs_addrm_start(&acxt, parent_sd);
Tejun Heo23dc2792007-08-02 21:38:03 +0900599 rc = sysfs_add_one(&acxt, sd);
600 sysfs_addrm_finish(&acxt);
Tejun Heo967e35d2007-07-18 16:38:11 +0900601
Tejun Heo23dc2792007-08-02 21:38:03 +0900602 if (rc == 0)
603 *p_sd = sd;
604 else
Tejun Heo967e35d2007-07-18 16:38:11 +0900605 sysfs_put(sd);
Tejun Heofc9f54b2007-06-14 03:45:17 +0900606
Tejun Heo23dc2792007-08-02 21:38:03 +0900607 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608}
609
Tejun Heo608e2662007-06-14 04:27:22 +0900610int sysfs_create_subdir(struct kobject *kobj, const char *name,
611 struct sysfs_dirent **p_sd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612{
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700613 return create_dir(kobj, kobj->sd,
614 KOBJ_NS_TYPE_NONE, NULL, name, p_sd);
615}
616
Serge E. Hallynbe867b12010-05-03 16:23:15 -0500617/**
618 * sysfs_read_ns_type: return associated ns_type
619 * @kobj: the kobject being queried
620 *
621 * Each kobject can be tagged with exactly one namespace type
622 * (i.e. network or user). Return the ns_type associated with
623 * this object if any
624 */
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700625static enum kobj_ns_type sysfs_read_ns_type(struct kobject *kobj)
626{
627 const struct kobj_ns_type_operations *ops;
628 enum kobj_ns_type type;
629
630 ops = kobj_child_ns_ops(kobj);
631 if (!ops)
632 return KOBJ_NS_TYPE_NONE;
633
634 type = ops->type;
635 BUG_ON(type <= KOBJ_NS_TYPE_NONE);
636 BUG_ON(type >= KOBJ_NS_TYPES);
637 BUG_ON(!kobj_ns_type_registered(type));
638
639 return type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640}
641
642/**
643 * sysfs_create_dir - create a directory for an object.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 * @kobj: object we're creating directory for.
645 */
Eric W. Biederman90bc6132007-07-31 19:15:08 +0900646int sysfs_create_dir(struct kobject * kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647{
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700648 enum kobj_ns_type type;
Tejun Heo608e2662007-06-14 04:27:22 +0900649 struct sysfs_dirent *parent_sd, *sd;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700650 const void *ns = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 int error = 0;
652
653 BUG_ON(!kobj);
654
Eric W. Biederman90bc6132007-07-31 19:15:08 +0900655 if (kobj->parent)
Tejun Heo608e2662007-06-14 04:27:22 +0900656 parent_sd = kobj->parent->sd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 else
Eric W. Biederman7d0c7d62007-08-20 21:36:30 +0900658 parent_sd = &sysfs_root;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700660 if (sysfs_ns_type(parent_sd))
661 ns = kobj->ktype->namespace(kobj);
662 type = sysfs_read_ns_type(kobj);
663
664 error = create_dir(kobj, parent_sd, type, ns, kobject_name(kobj), &sd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 if (!error)
Tejun Heo608e2662007-06-14 04:27:22 +0900666 kobj->sd = sd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 return error;
668}
669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
671 struct nameidata *nd)
672{
Tejun Heo6cb52142007-07-31 19:15:08 +0900673 struct dentry *ret = NULL;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700674 struct dentry *parent = dentry->d_parent;
675 struct sysfs_dirent *parent_sd = parent->d_fsdata;
Tejun Heoa7a04752007-08-02 21:38:02 +0900676 struct sysfs_dirent *sd;
Tejun Heofc9f54b2007-06-14 03:45:17 +0900677 struct inode *inode;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700678 enum kobj_ns_type type;
679 const void *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
Tejun Heo6cb52142007-07-31 19:15:08 +0900681 mutex_lock(&sysfs_mutex);
682
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700683 type = sysfs_ns_type(parent_sd);
684 ns = sysfs_info(dir->i_sb)->ns[type];
685
686 sd = sysfs_find_dirent(parent_sd, ns, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687
Tejun Heofc9f54b2007-06-14 03:45:17 +0900688 /* no such entry */
Tejun Heoe49452c2008-01-16 12:06:14 +0900689 if (!sd) {
690 ret = ERR_PTR(-ENOENT);
Tejun Heo6cb52142007-07-31 19:15:08 +0900691 goto out_unlock;
Tejun Heoe49452c2008-01-16 12:06:14 +0900692 }
Tejun Heofc9f54b2007-06-14 03:45:17 +0900693
694 /* attach dentry and inode */
Eric W. Biedermanfac26222010-02-12 19:22:27 -0800695 inode = sysfs_get_inode(dir->i_sb, sd);
Tejun Heo6cb52142007-07-31 19:15:08 +0900696 if (!inode) {
697 ret = ERR_PTR(-ENOMEM);
698 goto out_unlock;
699 }
Tejun Heo3007e992007-06-14 04:27:23 +0900700
Tejun Heod6b4fd22007-09-20 16:05:11 +0900701 /* instantiate and hash dentry */
Eric W. Biederman832b6af2009-11-20 16:08:56 -0800702 ret = d_find_alias(inode);
703 if (!ret) {
704 dentry->d_op = &sysfs_dentry_ops;
705 dentry->d_fsdata = sysfs_get(sd);
706 d_add(dentry, inode);
707 } else {
708 d_move(ret, dentry);
709 iput(inode);
710 }
Tejun Heofc9f54b2007-06-14 03:45:17 +0900711
Tejun Heo6cb52142007-07-31 19:15:08 +0900712 out_unlock:
Tejun Heo3007e992007-06-14 04:27:23 +0900713 mutex_unlock(&sysfs_mutex);
Tejun Heo6cb52142007-07-31 19:15:08 +0900714 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715}
716
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800717const struct inode_operations sysfs_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 .lookup = sysfs_lookup,
Eric W. Biedermane61ab4a2009-11-20 16:08:53 -0800719 .permission = sysfs_permission,
Maneesh Soni988d1862005-05-31 10:39:14 +0530720 .setattr = sysfs_setattr,
Eric W. Biedermane61ab4a2009-11-20 16:08:53 -0800721 .getattr = sysfs_getattr,
David P. Quigleyddd29ec2009-09-09 14:25:37 -0400722 .setxattr = sysfs_setxattr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723};
724
Tejun Heo608e2662007-06-14 04:27:22 +0900725static void remove_dir(struct sysfs_dirent *sd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726{
Tejun Heofb6896d2007-06-14 04:27:24 +0900727 struct sysfs_addrm_cxt acxt;
728
729 sysfs_addrm_start(&acxt, sd->s_parent);
Tejun Heofb6896d2007-06-14 04:27:24 +0900730 sysfs_remove_one(&acxt, sd);
731 sysfs_addrm_finish(&acxt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732}
733
Tejun Heo608e2662007-06-14 04:27:22 +0900734void sysfs_remove_subdir(struct sysfs_dirent *sd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735{
Tejun Heo608e2662007-06-14 04:27:22 +0900736 remove_dir(sd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737}
738
739
Tejun Heo608e2662007-06-14 04:27:22 +0900740static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741{
Tejun Heofb6896d2007-06-14 04:27:24 +0900742 struct sysfs_addrm_cxt acxt;
Tejun Heo0c73f182007-06-14 03:45:18 +0900743 struct sysfs_dirent **pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744
Tejun Heo608e2662007-06-14 04:27:22 +0900745 if (!dir_sd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 return;
747
Tejun Heo608e2662007-06-14 04:27:22 +0900748 pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
Tejun Heofb6896d2007-06-14 04:27:24 +0900749 sysfs_addrm_start(&acxt, dir_sd);
Tejun Heobc747f32007-09-20 16:05:12 +0900750 pos = &dir_sd->s_dir.children;
Tejun Heo0c73f182007-06-14 03:45:18 +0900751 while (*pos) {
752 struct sysfs_dirent *sd = *pos;
753
Eric W. Biederman3efa65b2007-08-20 21:36:30 +0900754 if (sysfs_type(sd) != SYSFS_DIR)
Tejun Heofb6896d2007-06-14 04:27:24 +0900755 sysfs_remove_one(&acxt, sd);
Tejun Heo41fc1c22007-08-02 21:38:03 +0900756 else
Tejun Heo0c73f182007-06-14 03:45:18 +0900757 pos = &(*pos)->s_sibling;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 }
Tejun Heofb6896d2007-06-14 04:27:24 +0900759 sysfs_addrm_finish(&acxt);
Tejun Heo0ab66082007-06-14 03:45:16 +0900760
Tejun Heo608e2662007-06-14 04:27:22 +0900761 remove_dir(dir_sd);
Eric W. Biedermanb592fcf2007-01-24 12:35:52 -0700762}
763
764/**
765 * sysfs_remove_dir - remove an object's directory.
766 * @kobj: object.
767 *
768 * The only thing special about this is that we remove any files in
769 * the directory before we remove the directory, and we've inlined
770 * what used to be sysfs_rmdir() below, instead of calling separately.
771 */
772
773void sysfs_remove_dir(struct kobject * kobj)
774{
Tejun Heo608e2662007-06-14 04:27:22 +0900775 struct sysfs_dirent *sd = kobj->sd;
Tejun Heoaecdced2007-06-14 03:45:15 +0900776
Tejun Heo5f995322007-06-14 04:27:23 +0900777 spin_lock(&sysfs_assoc_lock);
Tejun Heo608e2662007-06-14 04:27:22 +0900778 kobj->sd = NULL;
Tejun Heo5f995322007-06-14 04:27:23 +0900779 spin_unlock(&sysfs_assoc_lock);
Tejun Heoaecdced2007-06-14 03:45:15 +0900780
Tejun Heo608e2662007-06-14 04:27:22 +0900781 __sysfs_remove_dir(sd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782}
783
Eric W. Biedermanca1bab32009-11-20 16:08:57 -0800784int sysfs_rename(struct sysfs_dirent *sd,
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700785 struct sysfs_dirent *new_parent_sd, const void *new_ns,
786 const char *new_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787{
Tejun Heo51225032007-06-14 04:27:25 +0900788 const char *dup_name = NULL;
Tejun Heo996b7372007-06-14 03:45:14 +0900789 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
Eric W. Biederman832b6af2009-11-20 16:08:56 -0800791 mutex_lock(&sysfs_mutex);
Eric W. Biederman932ea2e2007-08-20 21:36:30 +0900792
Eric W. Biederman9918f9a2007-08-20 21:36:31 +0900793 error = 0;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700794 if ((sd->s_parent == new_parent_sd) && (sd->s_ns == new_ns) &&
Eric W. Biedermanca1bab32009-11-20 16:08:57 -0800795 (strcmp(sd->s_name, new_name) == 0))
Eric W. Biederman9918f9a2007-08-20 21:36:31 +0900796 goto out; /* nothing to rename */
797
Tejun Heo996b7372007-06-14 03:45:14 +0900798 error = -EEXIST;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700799 if (sysfs_find_dirent(new_parent_sd, new_ns, new_name))
Eric W. Biederman832b6af2009-11-20 16:08:56 -0800800 goto out;
Tejun Heo996b7372007-06-14 03:45:14 +0900801
Eric W. Biederman0b4a4fe2008-07-03 18:05:28 -0700802 /* rename sysfs_dirent */
Eric W. Biedermanca1bab32009-11-20 16:08:57 -0800803 if (strcmp(sd->s_name, new_name) != 0) {
804 error = -ENOMEM;
805 new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
806 if (!new_name)
807 goto out;
Tejun Heo996b7372007-06-14 03:45:14 +0900808
Eric W. Biedermanca1bab32009-11-20 16:08:57 -0800809 dup_name = sd->s_name;
810 sd->s_name = new_name;
811 }
812
813 /* Remove from old parent's list and insert into new parent's list. */
814 if (sd->s_parent != new_parent_sd) {
815 sysfs_unlink_sibling(sd);
816 sysfs_get(new_parent_sd);
817 sysfs_put(sd->s_parent);
818 sd->s_parent = new_parent_sd;
819 sysfs_link_sibling(sd);
820 }
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700821 sd->s_ns = new_ns;
Tejun Heo0c096b52007-06-14 03:45:15 +0900822
Tejun Heo996b7372007-06-14 03:45:14 +0900823 error = 0;
Eric W. Biederman9918f9a2007-08-20 21:36:31 +0900824 out:
Eric W. Biederman832b6af2009-11-20 16:08:56 -0800825 mutex_unlock(&sysfs_mutex);
826 kfree(dup_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 return error;
828}
829
Eric W. Biedermanca1bab32009-11-20 16:08:57 -0800830int sysfs_rename_dir(struct kobject *kobj, const char *new_name)
831{
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700832 struct sysfs_dirent *parent_sd = kobj->sd->s_parent;
833 const void *new_ns = NULL;
834
835 if (sysfs_ns_type(parent_sd))
836 new_ns = kobj->ktype->namespace(kobj);
837
838 return sysfs_rename(kobj->sd, parent_sd, new_ns, new_name);
Eric W. Biedermanca1bab32009-11-20 16:08:57 -0800839}
840
Tejun Heo51225032007-06-14 04:27:25 +0900841int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
Cornelia Huck8a824722006-11-20 17:07:51 +0100842{
Tejun Heo51225032007-06-14 04:27:25 +0900843 struct sysfs_dirent *sd = kobj->sd;
844 struct sysfs_dirent *new_parent_sd;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700845 const void *new_ns = NULL;
Cornelia Huck8a824722006-11-20 17:07:51 +0100846
Tejun Heo51225032007-06-14 04:27:25 +0900847 BUG_ON(!sd->s_parent);
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700848 if (sysfs_ns_type(sd->s_parent))
849 new_ns = kobj->ktype->namespace(kobj);
Eric W. Biedermanca1bab32009-11-20 16:08:57 -0800850 new_parent_sd = new_parent_kobj && new_parent_kobj->sd ?
Cornelia Hucka6a83572009-10-06 15:33:35 +0200851 new_parent_kobj->sd : &sysfs_root;
Cornelia Huck8a824722006-11-20 17:07:51 +0100852
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700853 return sysfs_rename(sd, new_parent_sd, new_ns, sd->s_name);
Cornelia Huck8a824722006-11-20 17:07:51 +0100854}
855
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856/* Relationship between s_mode and the DT_xxx types */
857static inline unsigned char dt_type(struct sysfs_dirent *sd)
858{
859 return (sd->s_mode >> 12) & 15;
860}
861
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800862static int sysfs_dir_release(struct inode *inode, struct file *filp)
863{
864 sysfs_put(filp->private_data);
865 return 0;
866}
867
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700868static struct sysfs_dirent *sysfs_dir_pos(const void *ns,
869 struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos)
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800870{
871 if (pos) {
872 int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) &&
873 pos->s_parent == parent_sd &&
874 ino == pos->s_ino;
875 sysfs_put(pos);
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700876 if (!valid)
877 pos = NULL;
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800878 }
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700879 if (!pos && (ino > 1) && (ino < INT_MAX)) {
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800880 pos = parent_sd->s_dir.children;
881 while (pos && (ino > pos->s_ino))
882 pos = pos->s_sibling;
883 }
Eric W. Biedermanaf10ec72010-03-30 11:31:27 -0700884 while (pos && pos->s_ns && pos->s_ns != ns)
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700885 pos = pos->s_sibling;
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800886 return pos;
887}
888
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700889static struct sysfs_dirent *sysfs_dir_next_pos(const void *ns,
890 struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos)
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800891{
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700892 pos = sysfs_dir_pos(ns, parent_sd, ino, pos);
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800893 if (pos)
894 pos = pos->s_sibling;
Eric W. Biedermanaf10ec72010-03-30 11:31:27 -0700895 while (pos && pos->s_ns && pos->s_ns != ns)
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700896 pos = pos->s_sibling;
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800897 return pos;
898}
899
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
901{
Josef "Jeff" Sipekf427f5d2006-12-08 02:36:36 -0800902 struct dentry *dentry = filp->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800904 struct sysfs_dirent *pos = filp->private_data;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700905 enum kobj_ns_type type;
906 const void *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 ino_t ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700909 type = sysfs_ns_type(parent_sd);
910 ns = sysfs_info(dentry->d_sb)->ns[type];
911
Eric W. Biederman3efa65b2007-08-20 21:36:30 +0900912 if (filp->f_pos == 0) {
913 ino = parent_sd->s_ino;
914 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0)
915 filp->f_pos++;
916 }
917 if (filp->f_pos == 1) {
918 if (parent_sd->s_parent)
919 ino = parent_sd->s_parent->s_ino;
920 else
Eric Sandeendc351252007-06-11 14:02:45 +0900921 ino = parent_sd->s_ino;
Eric W. Biederman3efa65b2007-08-20 21:36:30 +0900922 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 filp->f_pos++;
Eric W. Biederman3efa65b2007-08-20 21:36:30 +0900924 }
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800925 mutex_lock(&sysfs_mutex);
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700926 for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos);
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800927 pos;
Eric W. Biederman3ff195b2010-03-30 11:31:26 -0700928 pos = sysfs_dir_next_pos(ns, parent_sd, filp->f_pos, pos)) {
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800929 const char * name;
930 unsigned int type;
931 int len, ret;
Eric W. Biederman3efa65b2007-08-20 21:36:30 +0900932
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800933 name = pos->s_name;
934 len = strlen(name);
935 ino = pos->s_ino;
936 type = dt_type(pos);
937 filp->f_pos = ino;
938 filp->private_data = sysfs_get(pos);
Eric W. Biederman3efa65b2007-08-20 21:36:30 +0900939
Eric W. Biederman3efa65b2007-08-20 21:36:30 +0900940 mutex_unlock(&sysfs_mutex);
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800941 ret = filldir(dirent, name, len, filp->f_pos, ino, type);
942 mutex_lock(&sysfs_mutex);
943 if (ret < 0)
944 break;
945 }
946 mutex_unlock(&sysfs_mutex);
947 if ((filp->f_pos > 1) && !pos) { /* EOF */
948 filp->f_pos = INT_MAX;
949 filp->private_data = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 }
951 return 0;
952}
953
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800955const struct file_operations sysfs_dir_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 .read = generic_read_dir,
957 .readdir = sysfs_readdir,
Eric W. Biederman1e5289c2010-01-01 14:43:53 -0800958 .release = sysfs_dir_release,
Christoph Hellwig3222a3e2008-09-03 21:53:01 +0200959 .llseek = generic_file_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960};