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authorTejun Heo <tj@kernel.org>2013-11-28 14:54:33 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-29 21:08:39 -0500
commitfd7b9f7b9776b11df629e9dd3865320bf57ce588 (patch)
tree06e3d55ac0179dce37b477ae6941058b00bedc3c /fs/sysfs
parentffed24e22845a3da0ae01095ae3f11c8d16e889d (diff)
sysfs, kernfs: move dir core code to fs/kernfs/dir.c
Move core dir code to fs/kernfs/dir.c. fs/sysfs/dir.c now only contains sysfs_warn_dup() and sysfs wrappers around kernfs interfaces. The respective declarations in fs/sysfs/sysfs.h are moved to fs/kernfs/kernfs-internal.h. This is pure relocation. v2: sysfs_symlink_target_lock was mistakenly relocated to kernfs. It should remain with sysfs. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/sysfs')
-rw-r--r--fs/sysfs/dir.c986
-rw-r--r--fs/sysfs/sysfs.h13
2 files changed, 0 insertions, 999 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 0d806efcc9a6..e5c4e7118050 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -13,468 +13,12 @@
13#undef DEBUG 13#undef DEBUG
14 14
15#include <linux/fs.h> 15#include <linux/fs.h>
16#include <linux/mount.h>
17#include <linux/module.h>
18#include <linux/kobject.h> 16#include <linux/kobject.h>
19#include <linux/namei.h>
20#include <linux/idr.h>
21#include <linux/completion.h>
22#include <linux/mutex.h>
23#include <linux/slab.h> 17#include <linux/slab.h>
24#include <linux/security.h>
25#include <linux/hash.h>
26#include "sysfs.h" 18#include "sysfs.h"
27 19
28DEFINE_MUTEX(sysfs_mutex);
29DEFINE_SPINLOCK(sysfs_symlink_target_lock); 20DEFINE_SPINLOCK(sysfs_symlink_target_lock);
30 21
31#define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb)
32
33static DEFINE_SPINLOCK(sysfs_ino_lock);
34static DEFINE_IDA(sysfs_ino_ida);
35
36/**
37 * sysfs_name_hash
38 * @name: Null terminated string to hash
39 * @ns: Namespace tag to hash
40 *
41 * Returns 31 bit hash of ns + name (so it fits in an off_t )
42 */
43static unsigned int sysfs_name_hash(const char *name, const void *ns)
44{
45 unsigned long hash = init_name_hash();
46 unsigned int len = strlen(name);
47 while (len--)
48 hash = partial_name_hash(*name++, hash);
49 hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31));
50 hash &= 0x7fffffffU;
51 /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */
52 if (hash < 1)
53 hash += 2;
54 if (hash >= INT_MAX)
55 hash = INT_MAX - 1;
56 return hash;
57}
58
59static int sysfs_name_compare(unsigned int hash, const char *name,
60 const void *ns, const struct sysfs_dirent *sd)
61{
62 if (hash != sd->s_hash)
63 return hash - sd->s_hash;
64 if (ns != sd->s_ns)
65 return ns - sd->s_ns;
66 return strcmp(name, sd->s_name);
67}
68
69static int sysfs_sd_compare(const struct sysfs_dirent *left,
70 const struct sysfs_dirent *right)
71{
72 return sysfs_name_compare(left->s_hash, left->s_name, left->s_ns,
73 right);
74}
75
76/**
77 * sysfs_link_sibling - link sysfs_dirent into sibling rbtree
78 * @sd: sysfs_dirent of interest
79 *
80 * Link @sd into its sibling rbtree which starts from
81 * sd->s_parent->s_dir.children.
82 *
83 * Locking:
84 * mutex_lock(sysfs_mutex)
85 *
86 * RETURNS:
87 * 0 on susccess -EEXIST on failure.
88 */
89static int sysfs_link_sibling(struct sysfs_dirent *sd)
90{
91 struct rb_node **node = &sd->s_parent->s_dir.children.rb_node;
92 struct rb_node *parent = NULL;
93
94 if (sysfs_type(sd) == SYSFS_DIR)
95 sd->s_parent->s_dir.subdirs++;
96
97 while (*node) {
98 struct sysfs_dirent *pos;
99 int result;
100
101 pos = to_sysfs_dirent(*node);
102 parent = *node;
103 result = sysfs_sd_compare(sd, pos);
104 if (result < 0)
105 node = &pos->s_rb.rb_left;
106 else if (result > 0)
107 node = &pos->s_rb.rb_right;
108 else
109 return -EEXIST;
110 }
111 /* add new node and rebalance the tree */
112 rb_link_node(&sd->s_rb, parent, node);
113 rb_insert_color(&sd->s_rb, &sd->s_parent->s_dir.children);
114 return 0;
115}
116
117/**
118 * sysfs_unlink_sibling - unlink sysfs_dirent from sibling rbtree
119 * @sd: sysfs_dirent of interest
120 *
121 * Unlink @sd from its sibling rbtree which starts from
122 * sd->s_parent->s_dir.children.
123 *
124 * Locking:
125 * mutex_lock(sysfs_mutex)
126 */
127static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
128{
129 if (sysfs_type(sd) == SYSFS_DIR)
130 sd->s_parent->s_dir.subdirs--;
131
132 rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children);
133}
134
135/**
136 * sysfs_get_active - get an active reference to sysfs_dirent
137 * @sd: sysfs_dirent to get an active reference to
138 *
139 * Get an active reference of @sd. This function is noop if @sd
140 * is NULL.
141 *
142 * RETURNS:
143 * Pointer to @sd on success, NULL on failure.
144 */
145struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
146{
147 if (unlikely(!sd))
148 return NULL;
149
150 if (!atomic_inc_unless_negative(&sd->s_active))
151 return NULL;
152
153 if (sd->s_flags & SYSFS_FLAG_LOCKDEP)
154 rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
155 return sd;
156}
157
158/**
159 * sysfs_put_active - put an active reference to sysfs_dirent
160 * @sd: sysfs_dirent to put an active reference to
161 *
162 * Put an active reference to @sd. This function is noop if @sd
163 * is NULL.
164 */
165void sysfs_put_active(struct sysfs_dirent *sd)
166{
167 int v;
168
169 if (unlikely(!sd))
170 return;
171
172 if (sd->s_flags & SYSFS_FLAG_LOCKDEP)
173 rwsem_release(&sd->dep_map, 1, _RET_IP_);
174 v = atomic_dec_return(&sd->s_active);
175 if (likely(v != SD_DEACTIVATED_BIAS))
176 return;
177
178 /* atomic_dec_return() is a mb(), we'll always see the updated
179 * sd->u.completion.
180 */
181 complete(sd->u.completion);
182}
183
184/**
185 * sysfs_deactivate - deactivate sysfs_dirent
186 * @sd: sysfs_dirent to deactivate
187 *
188 * Deny new active references and drain existing ones.
189 */
190static void sysfs_deactivate(struct sysfs_dirent *sd)
191{
192 DECLARE_COMPLETION_ONSTACK(wait);
193 int v;
194
195 BUG_ON(!(sd->s_flags & SYSFS_FLAG_REMOVED));
196
197 if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF))
198 return;
199
200 sd->u.completion = (void *)&wait;
201
202 rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_);
203 /* atomic_add_return() is a mb(), put_active() will always see
204 * the updated sd->u.completion.
205 */
206 v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
207
208 if (v != SD_DEACTIVATED_BIAS) {
209 lock_contended(&sd->dep_map, _RET_IP_);
210 wait_for_completion(&wait);
211 }
212
213 lock_acquired(&sd->dep_map, _RET_IP_);
214 rwsem_release(&sd->dep_map, 1, _RET_IP_);
215}
216
217static int sysfs_alloc_ino(unsigned int *pino)
218{
219 int ino, rc;
220
221 retry:
222 spin_lock(&sysfs_ino_lock);
223 rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino);
224 spin_unlock(&sysfs_ino_lock);
225
226 if (rc == -EAGAIN) {
227 if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL))
228 goto retry;
229 rc = -ENOMEM;
230 }
231
232 *pino = ino;
233 return rc;
234}
235
236static void sysfs_free_ino(unsigned int ino)
237{
238 spin_lock(&sysfs_ino_lock);
239 ida_remove(&sysfs_ino_ida, ino);
240 spin_unlock(&sysfs_ino_lock);
241}
242
243/**
244 * kernfs_get - get a reference count on a sysfs_dirent
245 * @sd: the target sysfs_dirent
246 */
247void kernfs_get(struct sysfs_dirent *sd)
248{
249 if (sd) {
250 WARN_ON(!atomic_read(&sd->s_count));
251 atomic_inc(&sd->s_count);
252 }
253}
254EXPORT_SYMBOL_GPL(kernfs_get);
255
256/**
257 * kernfs_put - put a reference count on a sysfs_dirent
258 * @sd: the target sysfs_dirent
259 *
260 * Put a reference count of @sd and destroy it if it reached zero.
261 */
262void kernfs_put(struct sysfs_dirent *sd)
263{
264 struct sysfs_dirent *parent_sd;
265
266 if (!sd || !atomic_dec_and_test(&sd->s_count))
267 return;
268 repeat:
269 /* Moving/renaming is always done while holding reference.
270 * sd->s_parent won't change beneath us.
271 */
272 parent_sd = sd->s_parent;
273
274 WARN(!(sd->s_flags & SYSFS_FLAG_REMOVED),
275 "sysfs: free using entry: %s/%s\n",
276 parent_sd ? parent_sd->s_name : "", sd->s_name);
277
278 if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
279 kernfs_put(sd->s_symlink.target_sd);
280 if (sysfs_type(sd) & SYSFS_COPY_NAME)
281 kfree(sd->s_name);
282 if (sd->s_iattr && sd->s_iattr->ia_secdata)
283 security_release_secctx(sd->s_iattr->ia_secdata,
284 sd->s_iattr->ia_secdata_len);
285 kfree(sd->s_iattr);
286 sysfs_free_ino(sd->s_ino);
287 kmem_cache_free(sysfs_dir_cachep, sd);
288
289 sd = parent_sd;
290 if (sd && atomic_dec_and_test(&sd->s_count))
291 goto repeat;
292}
293EXPORT_SYMBOL_GPL(kernfs_put);
294
295static int sysfs_dentry_delete(const struct dentry *dentry)
296{
297 struct sysfs_dirent *sd = dentry->d_fsdata;
298 return !(sd && !(sd->s_flags & SYSFS_FLAG_REMOVED));
299}
300
301static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
302{
303 struct sysfs_dirent *sd;
304
305 if (flags & LOOKUP_RCU)
306 return -ECHILD;
307
308 sd = dentry->d_fsdata;
309 mutex_lock(&sysfs_mutex);
310
311 /* The sysfs dirent has been deleted */
312 if (sd->s_flags & SYSFS_FLAG_REMOVED)
313 goto out_bad;
314
315 /* The sysfs dirent has been moved? */
316 if (dentry->d_parent->d_fsdata != sd->s_parent)
317 goto out_bad;
318
319 /* The sysfs dirent has been renamed */
320 if (strcmp(dentry->d_name.name, sd->s_name) != 0)
321 goto out_bad;
322
323 /* The sysfs dirent has been moved to a different namespace */
324 if (sd->s_parent && (sd->s_parent->s_flags & SYSFS_FLAG_NS) &&
325 sysfs_info(dentry->d_sb)->ns != sd->s_ns)
326 goto out_bad;
327
328 mutex_unlock(&sysfs_mutex);
329out_valid:
330 return 1;
331out_bad:
332 /* Remove the dentry from the dcache hashes.
333 * If this is a deleted dentry we use d_drop instead of d_delete
334 * so sysfs doesn't need to cope with negative dentries.
335 *
336 * If this is a dentry that has simply been renamed we
337 * use d_drop to remove it from the dcache lookup on its
338 * old parent. If this dentry persists later when a lookup
339 * is performed at its new name the dentry will be readded
340 * to the dcache hashes.
341 */
342 mutex_unlock(&sysfs_mutex);
343
344 /* If we have submounts we must allow the vfs caches
345 * to lie about the state of the filesystem to prevent
346 * leaks and other nasty things.
347 */
348 if (check_submounts_and_drop(dentry) != 0)
349 goto out_valid;
350
351 return 0;
352}
353
354static void sysfs_dentry_release(struct dentry *dentry)
355{
356 kernfs_put(dentry->d_fsdata);
357}
358
359const struct dentry_operations sysfs_dentry_ops = {
360 .d_revalidate = sysfs_dentry_revalidate,
361 .d_delete = sysfs_dentry_delete,
362 .d_release = sysfs_dentry_release,
363};
364
365struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
366{
367 char *dup_name = NULL;
368 struct sysfs_dirent *sd;
369
370 if (type & SYSFS_COPY_NAME) {
371 name = dup_name = kstrdup(name, GFP_KERNEL);
372 if (!name)
373 return NULL;
374 }
375
376 sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
377 if (!sd)
378 goto err_out1;
379
380 if (sysfs_alloc_ino(&sd->s_ino))
381 goto err_out2;
382
383 atomic_set(&sd->s_count, 1);
384 atomic_set(&sd->s_active, 0);
385
386 sd->s_name = name;
387 sd->s_mode = mode;
388 sd->s_flags = type | SYSFS_FLAG_REMOVED;
389
390 return sd;
391
392 err_out2:
393 kmem_cache_free(sysfs_dir_cachep, sd);
394 err_out1:
395 kfree(dup_name);
396 return NULL;
397}
398
399/**
400 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
401 * @acxt: pointer to sysfs_addrm_cxt to be used
402 *
403 * This function is called when the caller is about to add or remove
404 * sysfs_dirent. This function acquires sysfs_mutex. @acxt is used
405 * to keep and pass context to other addrm functions.
406 *
407 * LOCKING:
408 * Kernel thread context (may sleep). sysfs_mutex is locked on
409 * return.
410 */
411void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt)
412 __acquires(sysfs_mutex)
413{
414 memset(acxt, 0, sizeof(*acxt));
415
416 mutex_lock(&sysfs_mutex);
417}
418
419/**
420 * sysfs_add_one - add sysfs_dirent to parent without warning
421 * @acxt: addrm context to use
422 * @sd: sysfs_dirent to be added
423 * @parent_sd: the parent sysfs_dirent to add @sd to
424 *
425 * Get @parent_sd and set @sd->s_parent to it and increment nlink of
426 * the parent inode if @sd is a directory and link into the children
427 * list of the parent.
428 *
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().
435 *
436 * RETURNS:
437 * 0 on success, -EEXIST if entry with the given name already
438 * exists.
439 */
440int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
441 struct sysfs_dirent *parent_sd)
442{
443 bool has_ns = parent_sd->s_flags & SYSFS_FLAG_NS;
444 struct sysfs_inode_attrs *ps_iattr;
445 int ret;
446
447 if (has_ns != (bool)sd->s_ns) {
448 WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
449 has_ns ? "required" : "invalid",
450 parent_sd->s_name, sd->s_name);
451 return -EINVAL;
452 }
453
454 if (sysfs_type(parent_sd) != SYSFS_DIR)
455 return -EINVAL;
456
457 sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns);
458 sd->s_parent = parent_sd;
459 kernfs_get(parent_sd);
460
461 ret = sysfs_link_sibling(sd);
462 if (ret)
463 return ret;
464
465 /* Update timestamps on the parent */
466 ps_iattr = parent_sd->s_iattr;
467 if (ps_iattr) {
468 struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
469 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
470 }
471
472 /* Mark the entry added into directory tree */
473 sd->s_flags &= ~SYSFS_FLAG_REMOVED;
474
475 return 0;
476}
477
478/** 22/**
479 * sysfs_pathname - return full path to sysfs dirent 23 * sysfs_pathname - return full path to sysfs dirent
480 * @sd: sysfs_dirent whose path we want 24 * @sd: sysfs_dirent whose path we want
@@ -511,181 +55,6 @@ void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name)
511} 55}
512 56
513/** 57/**
514 * sysfs_remove_one - remove sysfs_dirent from parent
515 * @acxt: addrm context to use
516 * @sd: sysfs_dirent to be removed
517 *
518 * Mark @sd removed and drop nlink of parent inode if @sd is a
519 * directory. @sd is unlinked from the children list.
520 *
521 * This function should be called between calls to
522 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
523 * passed the same @acxt as passed to sysfs_addrm_start().
524 *
525 * LOCKING:
526 * Determined by sysfs_addrm_start().
527 */
528static void sysfs_remove_one(struct sysfs_addrm_cxt *acxt,
529 struct sysfs_dirent *sd)
530{
531 struct sysfs_inode_attrs *ps_iattr;
532
533 /*
534 * Removal can be called multiple times on the same node. Only the
535 * first invocation is effective and puts the base ref.
536 */
537 if (sd->s_flags & SYSFS_FLAG_REMOVED)
538 return;
539
540 sysfs_unlink_sibling(sd);
541
542 /* Update timestamps on the parent */
543 ps_iattr = sd->s_parent->s_iattr;
544 if (ps_iattr) {
545 struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
546 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
547 }
548
549 sd->s_flags |= SYSFS_FLAG_REMOVED;
550 sd->u.removed_list = acxt->removed;
551 acxt->removed = sd;
552}
553
554/**
555 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
556 * @acxt: addrm context to finish up
557 *
558 * Finish up sysfs_dirent add/remove. Resources acquired by
559 * sysfs_addrm_start() are released and removed sysfs_dirents are
560 * cleaned up.
561 *
562 * LOCKING:
563 * sysfs_mutex is released.
564 */
565void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
566 __releases(sysfs_mutex)
567{
568 /* release resources acquired by sysfs_addrm_start() */
569 mutex_unlock(&sysfs_mutex);
570
571 /* kill removed sysfs_dirents */
572 while (acxt->removed) {
573 struct sysfs_dirent *sd = acxt->removed;
574
575 acxt->removed = sd->u.removed_list;
576
577 sysfs_deactivate(sd);
578 sysfs_unmap_bin_file(sd);
579 kernfs_put(sd);
580 }
581}
582
583/**
584 * kernfs_find_ns - find sysfs_dirent with the given name
585 * @parent: sysfs_dirent to search under
586 * @name: name to look for
587 * @ns: the namespace tag to use
588 *
589 * Look for sysfs_dirent with name @name under @parent. Returns pointer to
590 * the found sysfs_dirent on success, %NULL on failure.
591 */
592static struct sysfs_dirent *kernfs_find_ns(struct sysfs_dirent *parent,
593 const unsigned char *name,
594 const void *ns)
595{
596 struct rb_node *node = parent->s_dir.children.rb_node;
597 bool has_ns = parent->s_flags & SYSFS_FLAG_NS;
598 unsigned int hash;
599
600 lockdep_assert_held(&sysfs_mutex);
601
602 if (has_ns != (bool)ns) {
603 WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
604 has_ns ? "required" : "invalid",
605 parent->s_name, name);
606 return NULL;
607 }
608
609 hash = sysfs_name_hash(name, ns);
610 while (node) {
611 struct sysfs_dirent *sd;
612 int result;
613
614 sd = to_sysfs_dirent(node);
615 result = sysfs_name_compare(hash, name, ns, sd);
616 if (result < 0)
617 node = node->rb_left;
618 else if (result > 0)
619 node = node->rb_right;
620 else
621 return sd;
622 }
623 return NULL;
624}
625
626/**
627 * kernfs_find_and_get_ns - find and get sysfs_dirent with the given name
628 * @parent: sysfs_dirent to search under
629 * @name: name to look for
630 * @ns: the namespace tag to use
631 *
632 * Look for sysfs_dirent with name @name under @parent and get a reference
633 * if found. This function may sleep and returns pointer to the found
634 * sysfs_dirent on success, %NULL on failure.
635 */
636struct sysfs_dirent *kernfs_find_and_get_ns(struct sysfs_dirent *parent,
637 const char *name, const void *ns)
638{
639 struct sysfs_dirent *sd;
640
641 mutex_lock(&sysfs_mutex);
642 sd = kernfs_find_ns(parent, name, ns);
643 kernfs_get(sd);
644 mutex_unlock(&sysfs_mutex);
645
646 return sd;
647}
648EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns);
649
650/**
651 * kernfs_create_dir_ns - create a directory
652 * @parent: parent in which to create a new directory
653 * @name: name of the new directory
654 * @priv: opaque data associated with the new directory
655 * @ns: optional namespace tag of the directory
656 *
657 * Returns the created node on success, ERR_PTR() value on failure.
658 */
659struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,
660 const char *name, void *priv,
661 const void *ns)
662{
663 umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
664 struct sysfs_addrm_cxt acxt;
665 struct sysfs_dirent *sd;
666 int rc;
667
668 /* allocate */
669 sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
670 if (!sd)
671 return ERR_PTR(-ENOMEM);
672
673 sd->s_ns = ns;
674 sd->priv = priv;
675
676 /* link in */
677 sysfs_addrm_start(&acxt);
678 rc = sysfs_add_one(&acxt, sd, parent);
679 sysfs_addrm_finish(&acxt);
680
681 if (!rc)
682 return sd;
683
684 kernfs_put(sd);
685 return ERR_PTR(rc);
686}
687
688/**
689 * sysfs_create_dir_ns - create a directory for an object with a namespace tag 58 * sysfs_create_dir_ns - create a directory for an object with a namespace tag
690 * @kobj: object we're creating directory for 59 * @kobj: object we're creating directory for
691 * @ns: the namespace tag to use 60 * @ns: the namespace tag to use
@@ -715,177 +84,6 @@ int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
715 return 0; 84 return 0;
716} 85}
717 86
718static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry,
719 unsigned int flags)
720{
721 struct dentry *ret = NULL;
722 struct dentry *parent = dentry->d_parent;
723 struct sysfs_dirent *parent_sd = parent->d_fsdata;
724 struct sysfs_dirent *sd;
725 struct inode *inode;
726 const void *ns = NULL;
727
728 mutex_lock(&sysfs_mutex);
729
730 if (parent_sd->s_flags & SYSFS_FLAG_NS)
731 ns = sysfs_info(dir->i_sb)->ns;
732
733 sd = kernfs_find_ns(parent_sd, dentry->d_name.name, ns);
734
735 /* no such entry */
736 if (!sd) {
737 ret = ERR_PTR(-ENOENT);
738 goto out_unlock;
739 }
740 kernfs_get(sd);
741 dentry->d_fsdata = sd;
742
743 /* attach dentry and inode */
744 inode = sysfs_get_inode(dir->i_sb, sd);
745 if (!inode) {
746 ret = ERR_PTR(-ENOMEM);
747 goto out_unlock;
748 }
749
750 /* instantiate and hash dentry */
751 ret = d_materialise_unique(dentry, inode);
752 out_unlock:
753 mutex_unlock(&sysfs_mutex);
754 return ret;
755}
756
757const struct inode_operations sysfs_dir_inode_operations = {
758 .lookup = sysfs_lookup,
759 .permission = sysfs_permission,
760 .setattr = sysfs_setattr,
761 .getattr = sysfs_getattr,
762 .setxattr = sysfs_setxattr,
763};
764
765static struct sysfs_dirent *sysfs_leftmost_descendant(struct sysfs_dirent *pos)
766{
767 struct sysfs_dirent *last;
768
769 while (true) {
770 struct rb_node *rbn;
771
772 last = pos;
773
774 if (sysfs_type(pos) != SYSFS_DIR)
775 break;
776
777 rbn = rb_first(&pos->s_dir.children);
778 if (!rbn)
779 break;
780
781 pos = to_sysfs_dirent(rbn);
782 }
783
784 return last;
785}
786
787/**
788 * sysfs_next_descendant_post - find the next descendant for post-order walk
789 * @pos: the current position (%NULL to initiate traversal)
790 * @root: sysfs_dirent whose descendants to walk
791 *
792 * Find the next descendant to visit for post-order traversal of @root's
793 * descendants. @root is included in the iteration and the last node to be
794 * visited.
795 */
796static struct sysfs_dirent *sysfs_next_descendant_post(struct sysfs_dirent *pos,
797 struct sysfs_dirent *root)
798{
799 struct rb_node *rbn;
800
801 lockdep_assert_held(&sysfs_mutex);
802
803 /* if first iteration, visit leftmost descendant which may be root */
804 if (!pos)
805 return sysfs_leftmost_descendant(root);
806
807 /* if we visited @root, we're done */
808 if (pos == root)
809 return NULL;
810
811 /* if there's an unvisited sibling, visit its leftmost descendant */
812 rbn = rb_next(&pos->s_rb);
813 if (rbn)
814 return sysfs_leftmost_descendant(to_sysfs_dirent(rbn));
815
816 /* no sibling left, visit parent */
817 return pos->s_parent;
818}
819
820static void __kernfs_remove(struct sysfs_addrm_cxt *acxt,
821 struct sysfs_dirent *sd)
822{
823 struct sysfs_dirent *pos, *next;
824
825 if (!sd)
826 return;
827
828 pr_debug("sysfs %s: removing\n", sd->s_name);
829
830 next = NULL;
831 do {
832 pos = next;
833 next = sysfs_next_descendant_post(pos, sd);
834 if (pos)
835 sysfs_remove_one(acxt, pos);
836 } while (next);
837}
838
839/**
840 * kernfs_remove - remove a sysfs_dirent recursively
841 * @sd: the sysfs_dirent to remove
842 *
843 * Remove @sd along with all its subdirectories and files.
844 */
845void kernfs_remove(struct sysfs_dirent *sd)
846{
847 struct sysfs_addrm_cxt acxt;
848
849 sysfs_addrm_start(&acxt);
850 __kernfs_remove(&acxt, sd);
851 sysfs_addrm_finish(&acxt);
852}
853
854/**
855 * kernfs_remove_by_name_ns - find a sysfs_dirent by name and remove it
856 * @dir_sd: parent of the target
857 * @name: name of the sysfs_dirent to remove
858 * @ns: namespace tag of the sysfs_dirent to remove
859 *
860 * Look for the sysfs_dirent with @name and @ns under @dir_sd and remove
861 * it. Returns 0 on success, -ENOENT if such entry doesn't exist.
862 */
863int kernfs_remove_by_name_ns(struct sysfs_dirent *dir_sd, const char *name,
864 const void *ns)
865{
866 struct sysfs_addrm_cxt acxt;
867 struct sysfs_dirent *sd;
868
869 if (!dir_sd) {
870 WARN(1, KERN_WARNING "sysfs: can not remove '%s', no directory\n",
871 name);
872 return -ENOENT;
873 }
874
875 sysfs_addrm_start(&acxt);
876
877 sd = kernfs_find_ns(dir_sd, name, ns);
878 if (sd)
879 __kernfs_remove(&acxt, sd);
880
881 sysfs_addrm_finish(&acxt);
882
883 if (sd)
884 return 0;
885 else
886 return -ENOENT;
887}
888
889/** 87/**
890 * sysfs_remove_dir - remove an object's directory. 88 * sysfs_remove_dir - remove an object's directory.
891 * @kobj: object. 89 * @kobj: object.
@@ -920,57 +118,6 @@ void sysfs_remove_dir(struct kobject *kobj)
920 } 118 }
921} 119}
922 120
923/**
924 * kernfs_rename_ns - move and rename a kernfs_node
925 * @sd: target node
926 * @new_parent: new parent to put @sd under
927 * @new_name: new name
928 * @new_ns: new namespace tag
929 */
930int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent,
931 const char *new_name, const void *new_ns)
932{
933 int error;
934
935 mutex_lock(&sysfs_mutex);
936
937 error = 0;
938 if ((sd->s_parent == new_parent) && (sd->s_ns == new_ns) &&
939 (strcmp(sd->s_name, new_name) == 0))
940 goto out; /* nothing to rename */
941
942 error = -EEXIST;
943 if (kernfs_find_ns(new_parent, new_name, new_ns))
944 goto out;
945
946 /* rename sysfs_dirent */
947 if (strcmp(sd->s_name, new_name) != 0) {
948 error = -ENOMEM;
949 new_name = kstrdup(new_name, GFP_KERNEL);
950 if (!new_name)
951 goto out;
952
953 kfree(sd->s_name);
954 sd->s_name = new_name;
955 }
956
957 /*
958 * Move to the appropriate place in the appropriate directories rbtree.
959 */
960 sysfs_unlink_sibling(sd);
961 kernfs_get(new_parent);
962 kernfs_put(sd->s_parent);
963 sd->s_ns = new_ns;
964 sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns);
965 sd->s_parent = new_parent;
966 sysfs_link_sibling(sd);
967
968 error = 0;
969 out:
970 mutex_unlock(&sysfs_mutex);
971 return error;
972}
973
974int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, 121int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
975 const void *new_ns) 122 const void *new_ns)
976{ 123{
@@ -991,136 +138,3 @@ int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj,
991 138
992 return kernfs_rename_ns(sd, new_parent_sd, sd->s_name, new_ns); 139 return kernfs_rename_ns(sd, new_parent_sd, sd->s_name, new_ns);
993} 140}
994
995/**
996 * kernfs_enable_ns - enable namespace under a directory
997 * @sd: directory of interest, should be empty
998 *
999 * This is to be called right after @sd is created to enable namespace
1000 * under it. All children of @sd must have non-NULL namespace tags and
1001 * only the ones which match the super_block's tag will be visible.
1002 */
1003void kernfs_enable_ns(struct sysfs_dirent *sd)
1004{
1005 WARN_ON_ONCE(sysfs_type(sd) != SYSFS_DIR);
1006 WARN_ON_ONCE(!RB_EMPTY_ROOT(&sd->s_dir.children));
1007 sd->s_flags |= SYSFS_FLAG_NS;
1008}
1009
1010/* Relationship between s_mode and the DT_xxx types */
1011static inline unsigned char dt_type(struct sysfs_dirent *sd)
1012{
1013 return (sd->s_mode >> 12) & 15;
1014}
1015
1016static int sysfs_dir_release(struct inode *inode, struct file *filp)
1017{
1018 kernfs_put(filp->private_data);
1019 return 0;
1020}
1021
1022static struct sysfs_dirent *sysfs_dir_pos(const void *ns,
1023 struct sysfs_dirent *parent_sd, loff_t hash, struct sysfs_dirent *pos)
1024{
1025 if (pos) {
1026 int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) &&
1027 pos->s_parent == parent_sd &&
1028 hash == pos->s_hash;
1029 kernfs_put(pos);
1030 if (!valid)
1031 pos = NULL;
1032 }
1033 if (!pos && (hash > 1) && (hash < INT_MAX)) {
1034 struct rb_node *node = parent_sd->s_dir.children.rb_node;
1035 while (node) {
1036 pos = to_sysfs_dirent(node);
1037
1038 if (hash < pos->s_hash)
1039 node = node->rb_left;
1040 else if (hash > pos->s_hash)
1041 node = node->rb_right;
1042 else
1043 break;
1044 }
1045 }
1046 /* Skip over entries in the wrong namespace */
1047 while (pos && pos->s_ns != ns) {
1048 struct rb_node *node = rb_next(&pos->s_rb);
1049 if (!node)
1050 pos = NULL;
1051 else
1052 pos = to_sysfs_dirent(node);
1053 }
1054 return pos;
1055}
1056
1057static struct sysfs_dirent *sysfs_dir_next_pos(const void *ns,
1058 struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos)
1059{
1060 pos = sysfs_dir_pos(ns, parent_sd, ino, pos);
1061 if (pos)
1062 do {
1063 struct rb_node *node = rb_next(&pos->s_rb);
1064 if (!node)
1065 pos = NULL;
1066 else
1067 pos = to_sysfs_dirent(node);
1068 } while (pos && pos->s_ns != ns);
1069 return pos;
1070}
1071
1072static int sysfs_readdir(struct file *file, struct dir_context *ctx)
1073{
1074 struct dentry *dentry = file->f_path.dentry;
1075 struct sysfs_dirent *parent_sd = dentry->d_fsdata;
1076 struct sysfs_dirent *pos = file->private_data;
1077 const void *ns = NULL;
1078
1079 if (!dir_emit_dots(file, ctx))
1080 return 0;
1081 mutex_lock(&sysfs_mutex);
1082
1083 if (parent_sd->s_flags & SYSFS_FLAG_NS)
1084 ns = sysfs_info(dentry->d_sb)->ns;
1085
1086 for (pos = sysfs_dir_pos(ns, parent_sd, ctx->pos, pos);
1087 pos;
1088 pos = sysfs_dir_next_pos(ns, parent_sd, ctx->pos, pos)) {
1089 const char *name = pos->s_name;
1090 unsigned int type = dt_type(pos);
1091 int len = strlen(name);
1092 ino_t ino = pos->s_ino;
1093
1094 ctx->pos = pos->s_hash;
1095 file->private_data = pos;
1096 kernfs_get(pos);
1097
1098 mutex_unlock(&sysfs_mutex);
1099 if (!dir_emit(ctx, name, len, ino, type))
1100 return 0;
1101 mutex_lock(&sysfs_mutex);
1102 }
1103 mutex_unlock(&sysfs_mutex);
1104 file->private_data = NULL;
1105 ctx->pos = INT_MAX;
1106 return 0;
1107}
1108
1109static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence)
1110{
1111 struct inode *inode = file_inode(file);
1112 loff_t ret;
1113
1114 mutex_lock(&inode->i_mutex);
1115 ret = generic_file_llseek(file, offset, whence);
1116 mutex_unlock(&inode->i_mutex);
1117
1118 return ret;
1119}
1120
1121const struct file_operations sysfs_dir_operations = {
1122 .read = generic_read_dir,
1123 .iterate = sysfs_readdir,
1124 .release = sysfs_dir_release,
1125 .llseek = sysfs_dir_llseek,
1126};
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 93c1910783fc..972b4a4a5f90 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -34,22 +34,9 @@ extern struct kmem_cache *sysfs_dir_cachep;
34/* 34/*
35 * dir.c 35 * dir.c
36 */ 36 */
37extern struct mutex sysfs_mutex;
38extern spinlock_t sysfs_symlink_target_lock; 37extern spinlock_t sysfs_symlink_target_lock;
39extern const struct dentry_operations sysfs_dentry_ops;
40 38
41extern const struct file_operations sysfs_dir_operations;
42extern const struct inode_operations sysfs_dir_inode_operations;
43
44struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
45void sysfs_put_active(struct sysfs_dirent *sd);
46void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt);
47void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name); 39void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name);
48int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
49 struct sysfs_dirent *parent_sd);
50void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
51
52struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
53 40
54/* 41/*
55 * file.c 42 * file.c
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-22 03:23:42 -0500