2 * fs/kernfs/dir.c - kernfs directory implementation
4 * Copyright (c) 2001-3 Patrick Mochel
5 * Copyright (c) 2007 SUSE Linux Products GmbH
6 * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org>
8 * This file is released under the GPLv2.
11 #include <linux/sched.h>
13 #include <linux/namei.h>
14 #include <linux/idr.h>
15 #include <linux/slab.h>
16 #include <linux/security.h>
17 #include <linux/hash.h>
19 #include "kernfs-internal.h"
21 DEFINE_MUTEX(kernfs_mutex);
23 #define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb)
27 * @name: Null terminated string to hash
28 * @ns: Namespace tag to hash
30 * Returns 31 bit hash of ns + name (so it fits in an off_t )
32 static unsigned int kernfs_name_hash(const char *name, const void *ns)
34 unsigned long hash = init_name_hash();
35 unsigned int len = strlen(name);
37 hash = partial_name_hash(*name++, hash);
38 hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31));
40 /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */
48 static int kernfs_name_compare(unsigned int hash, const char *name,
49 const void *ns, const struct kernfs_node *kn)
52 return hash - kn->hash;
55 return strcmp(name, kn->name);
58 static int kernfs_sd_compare(const struct kernfs_node *left,
59 const struct kernfs_node *right)
61 return kernfs_name_compare(left->hash, left->name, left->ns, right);
65 * kernfs_link_sibling - link kernfs_node into sibling rbtree
66 * @kn: kernfs_node of interest
68 * Link @kn into its sibling rbtree which starts from
69 * @kn->parent->dir.children.
72 * mutex_lock(kernfs_mutex)
75 * 0 on susccess -EEXIST on failure.
77 static int kernfs_link_sibling(struct kernfs_node *kn)
79 struct rb_node **node = &kn->parent->dir.children.rb_node;
80 struct rb_node *parent = NULL;
82 if (kernfs_type(kn) == KERNFS_DIR)
83 kn->parent->dir.subdirs++;
86 struct kernfs_node *pos;
89 pos = rb_to_kn(*node);
91 result = kernfs_sd_compare(kn, pos);
93 node = &pos->rb.rb_left;
95 node = &pos->rb.rb_right;
99 /* add new node and rebalance the tree */
100 rb_link_node(&kn->rb, parent, node);
101 rb_insert_color(&kn->rb, &kn->parent->dir.children);
106 * kernfs_unlink_sibling - unlink kernfs_node from sibling rbtree
107 * @kn: kernfs_node of interest
109 * Unlink @kn from its sibling rbtree which starts from
110 * kn->parent->dir.children.
113 * mutex_lock(kernfs_mutex)
115 static void kernfs_unlink_sibling(struct kernfs_node *kn)
117 if (kernfs_type(kn) == KERNFS_DIR)
118 kn->parent->dir.subdirs--;
120 rb_erase(&kn->rb, &kn->parent->dir.children);
124 * kernfs_get_active - get an active reference to kernfs_node
125 * @kn: kernfs_node to get an active reference to
127 * Get an active reference of @kn. This function is noop if @kn
131 * Pointer to @kn on success, NULL on failure.
133 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn)
138 if (!atomic_inc_unless_negative(&kn->active))
141 if (kn->flags & KERNFS_LOCKDEP)
142 rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_);
147 * kernfs_put_active - put an active reference to kernfs_node
148 * @kn: kernfs_node to put an active reference to
150 * Put an active reference to @kn. This function is noop if @kn
153 void kernfs_put_active(struct kernfs_node *kn)
155 struct kernfs_root *root = kernfs_root(kn);
161 if (kn->flags & KERNFS_LOCKDEP)
162 rwsem_release(&kn->dep_map, 1, _RET_IP_);
163 v = atomic_dec_return(&kn->active);
164 if (likely(v != KN_DEACTIVATED_BIAS))
167 wake_up_all(&root->deactivate_waitq);
171 * kernfs_deactivate - deactivate kernfs_node
172 * @kn: kernfs_node to deactivate
174 * Deny new active references and drain existing ones.
176 static void kernfs_deactivate(struct kernfs_node *kn)
178 struct kernfs_root *root = kernfs_root(kn);
180 BUG_ON(!(kn->flags & KERNFS_REMOVED));
182 if (!(kernfs_type(kn) & KERNFS_ACTIVE_REF))
185 rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_);
187 atomic_add(KN_DEACTIVATED_BIAS, &kn->active);
189 if (atomic_read(&kn->active) != KN_DEACTIVATED_BIAS)
190 lock_contended(&kn->dep_map, _RET_IP_);
192 wait_event(root->deactivate_waitq,
193 atomic_read(&kn->active) == KN_DEACTIVATED_BIAS);
195 lock_acquired(&kn->dep_map, _RET_IP_);
196 rwsem_release(&kn->dep_map, 1, _RET_IP_);
200 * kernfs_get - get a reference count on a kernfs_node
201 * @kn: the target kernfs_node
203 void kernfs_get(struct kernfs_node *kn)
206 WARN_ON(!atomic_read(&kn->count));
207 atomic_inc(&kn->count);
210 EXPORT_SYMBOL_GPL(kernfs_get);
213 * kernfs_put - put a reference count on a kernfs_node
214 * @kn: the target kernfs_node
216 * Put a reference count of @kn and destroy it if it reached zero.
218 void kernfs_put(struct kernfs_node *kn)
220 struct kernfs_node *parent;
221 struct kernfs_root *root;
223 if (!kn || !atomic_dec_and_test(&kn->count))
225 root = kernfs_root(kn);
227 /* Moving/renaming is always done while holding reference.
228 * kn->parent won't change beneath us.
232 WARN(!(kn->flags & KERNFS_REMOVED), "kernfs: free using entry: %s/%s\n",
233 parent ? parent->name : "", kn->name);
235 if (kernfs_type(kn) == KERNFS_LINK)
236 kernfs_put(kn->symlink.target_kn);
237 if (!(kn->flags & KERNFS_STATIC_NAME))
240 if (kn->iattr->ia_secdata)
241 security_release_secctx(kn->iattr->ia_secdata,
242 kn->iattr->ia_secdata_len);
243 simple_xattrs_free(&kn->iattr->xattrs);
246 ida_simple_remove(&root->ino_ida, kn->ino);
247 kmem_cache_free(kernfs_node_cache, kn);
251 if (atomic_dec_and_test(&kn->count))
254 /* just released the root kn, free @root too */
255 ida_destroy(&root->ino_ida);
259 EXPORT_SYMBOL_GPL(kernfs_put);
261 static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
263 struct kernfs_node *kn;
265 if (flags & LOOKUP_RCU)
268 /* Always perform fresh lookup for negatives */
269 if (!dentry->d_inode)
270 goto out_bad_unlocked;
272 kn = dentry->d_fsdata;
273 mutex_lock(&kernfs_mutex);
275 /* The kernfs node has been deleted */
276 if (kn->flags & KERNFS_REMOVED)
279 /* The kernfs node has been moved? */
280 if (dentry->d_parent->d_fsdata != kn->parent)
283 /* The kernfs node has been renamed */
284 if (strcmp(dentry->d_name.name, kn->name) != 0)
287 /* The kernfs node has been moved to a different namespace */
288 if (kn->parent && kernfs_ns_enabled(kn->parent) &&
289 kernfs_info(dentry->d_sb)->ns != kn->ns)
292 mutex_unlock(&kernfs_mutex);
296 mutex_unlock(&kernfs_mutex);
299 * @dentry doesn't match the underlying kernfs node, drop the
300 * dentry and force lookup. If we have submounts we must allow the
301 * vfs caches to lie about the state of the filesystem to prevent
302 * leaks and other nasty things, so use check_submounts_and_drop()
303 * instead of d_drop().
305 if (check_submounts_and_drop(dentry) != 0)
311 static void kernfs_dop_release(struct dentry *dentry)
313 kernfs_put(dentry->d_fsdata);
316 const struct dentry_operations kernfs_dops = {
317 .d_revalidate = kernfs_dop_revalidate,
318 .d_release = kernfs_dop_release,
321 struct kernfs_node *kernfs_new_node(struct kernfs_root *root, const char *name,
322 umode_t mode, unsigned flags)
324 char *dup_name = NULL;
325 struct kernfs_node *kn;
328 if (!(flags & KERNFS_STATIC_NAME)) {
329 name = dup_name = kstrdup(name, GFP_KERNEL);
334 kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL);
338 ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL);
343 atomic_set(&kn->count, 1);
344 atomic_set(&kn->active, 0);
348 kn->flags = flags | KERNFS_REMOVED;
353 kmem_cache_free(kernfs_node_cache, kn);
360 * kernfs_addrm_start - prepare for kernfs_node add/remove
361 * @acxt: pointer to kernfs_addrm_cxt to be used
363 * This function is called when the caller is about to add or remove
364 * kernfs_node. This function acquires kernfs_mutex. @acxt is used
365 * to keep and pass context to other addrm functions.
368 * Kernel thread context (may sleep). kernfs_mutex is locked on
371 void kernfs_addrm_start(struct kernfs_addrm_cxt *acxt)
372 __acquires(kernfs_mutex)
374 memset(acxt, 0, sizeof(*acxt));
376 mutex_lock(&kernfs_mutex);
380 * kernfs_add_one - add kernfs_node to parent without warning
381 * @acxt: addrm context to use
382 * @kn: kernfs_node to be added
383 * @parent: the parent kernfs_node to add @kn to
385 * Get @parent and set @kn->parent to it and increment nlink of the
386 * parent inode if @kn is a directory and link into the children list
389 * This function should be called between calls to
390 * kernfs_addrm_start() and kernfs_addrm_finish() and should be passed
391 * the same @acxt as passed to kernfs_addrm_start().
394 * Determined by kernfs_addrm_start().
397 * 0 on success, -EEXIST if entry with the given name already
400 int kernfs_add_one(struct kernfs_addrm_cxt *acxt, struct kernfs_node *kn,
401 struct kernfs_node *parent)
403 bool has_ns = kernfs_ns_enabled(parent);
404 struct kernfs_iattrs *ps_iattr;
407 if (has_ns != (bool)kn->ns) {
408 WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n",
409 has_ns ? "required" : "invalid", parent->name, kn->name);
413 if (kernfs_type(parent) != KERNFS_DIR)
416 if (parent->flags & KERNFS_REMOVED)
419 kn->hash = kernfs_name_hash(kn->name, kn->ns);
423 ret = kernfs_link_sibling(kn);
427 /* Update timestamps on the parent */
428 ps_iattr = parent->iattr;
430 struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
431 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
434 /* Mark the entry added into directory tree */
435 kn->flags &= ~KERNFS_REMOVED;
441 * kernfs_remove_one - remove kernfs_node from parent
442 * @acxt: addrm context to use
443 * @kn: kernfs_node to be removed
445 * Mark @kn removed and drop nlink of parent inode if @kn is a
446 * directory. @kn is unlinked from the children list.
448 * This function should be called between calls to
449 * kernfs_addrm_start() and kernfs_addrm_finish() and should be
450 * passed the same @acxt as passed to kernfs_addrm_start().
453 * Determined by kernfs_addrm_start().
455 static void kernfs_remove_one(struct kernfs_addrm_cxt *acxt,
456 struct kernfs_node *kn)
458 struct kernfs_iattrs *ps_iattr;
461 * Removal can be called multiple times on the same node. Only the
462 * first invocation is effective and puts the base ref.
464 if (kn->flags & KERNFS_REMOVED)
468 kernfs_unlink_sibling(kn);
470 /* Update timestamps on the parent */
471 ps_iattr = kn->parent->iattr;
473 ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME;
474 ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME;
478 kn->flags |= KERNFS_REMOVED;
479 kn->u.removed_list = acxt->removed;
484 * kernfs_addrm_finish - finish up kernfs_node add/remove
485 * @acxt: addrm context to finish up
487 * Finish up kernfs_node add/remove. Resources acquired by
488 * kernfs_addrm_start() are released and removed kernfs_nodes are
492 * kernfs_mutex is released.
494 void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt)
495 __releases(kernfs_mutex)
497 /* release resources acquired by kernfs_addrm_start() */
498 mutex_unlock(&kernfs_mutex);
500 /* kill removed kernfs_nodes */
501 while (acxt->removed) {
502 struct kernfs_node *kn = acxt->removed;
504 acxt->removed = kn->u.removed_list;
506 kernfs_deactivate(kn);
507 kernfs_unmap_bin_file(kn);
513 * kernfs_find_ns - find kernfs_node with the given name
514 * @parent: kernfs_node to search under
515 * @name: name to look for
516 * @ns: the namespace tag to use
518 * Look for kernfs_node with name @name under @parent. Returns pointer to
519 * the found kernfs_node on success, %NULL on failure.
521 static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent,
522 const unsigned char *name,
525 struct rb_node *node = parent->dir.children.rb_node;
526 bool has_ns = kernfs_ns_enabled(parent);
529 lockdep_assert_held(&kernfs_mutex);
531 if (has_ns != (bool)ns) {
532 WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n",
533 has_ns ? "required" : "invalid", parent->name, name);
537 hash = kernfs_name_hash(name, ns);
539 struct kernfs_node *kn;
543 result = kernfs_name_compare(hash, name, ns, kn);
545 node = node->rb_left;
547 node = node->rb_right;
555 * kernfs_find_and_get_ns - find and get kernfs_node with the given name
556 * @parent: kernfs_node to search under
557 * @name: name to look for
558 * @ns: the namespace tag to use
560 * Look for kernfs_node with name @name under @parent and get a reference
561 * if found. This function may sleep and returns pointer to the found
562 * kernfs_node on success, %NULL on failure.
564 struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent,
565 const char *name, const void *ns)
567 struct kernfs_node *kn;
569 mutex_lock(&kernfs_mutex);
570 kn = kernfs_find_ns(parent, name, ns);
572 mutex_unlock(&kernfs_mutex);
576 EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns);
579 * kernfs_create_root - create a new kernfs hierarchy
580 * @kdops: optional directory syscall operations for the hierarchy
581 * @priv: opaque data associated with the new directory
583 * Returns the root of the new hierarchy on success, ERR_PTR() value on
586 struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv)
588 struct kernfs_root *root;
589 struct kernfs_node *kn;
591 root = kzalloc(sizeof(*root), GFP_KERNEL);
593 return ERR_PTR(-ENOMEM);
595 ida_init(&root->ino_ida);
597 kn = kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, KERNFS_DIR);
599 ida_destroy(&root->ino_ida);
601 return ERR_PTR(-ENOMEM);
604 kn->flags &= ~KERNFS_REMOVED;
608 root->dir_ops = kdops;
610 init_waitqueue_head(&root->deactivate_waitq);
616 * kernfs_destroy_root - destroy a kernfs hierarchy
617 * @root: root of the hierarchy to destroy
619 * Destroy the hierarchy anchored at @root by removing all existing
620 * directories and destroying @root.
622 void kernfs_destroy_root(struct kernfs_root *root)
624 kernfs_remove(root->kn); /* will also free @root */
628 * kernfs_create_dir_ns - create a directory
629 * @parent: parent in which to create a new directory
630 * @name: name of the new directory
631 * @mode: mode of the new directory
632 * @priv: opaque data associated with the new directory
633 * @ns: optional namespace tag of the directory
635 * Returns the created node on success, ERR_PTR() value on failure.
637 struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent,
638 const char *name, umode_t mode,
639 void *priv, const void *ns)
641 struct kernfs_addrm_cxt acxt;
642 struct kernfs_node *kn;
646 kn = kernfs_new_node(kernfs_root(parent), name, mode | S_IFDIR,
649 return ERR_PTR(-ENOMEM);
651 kn->dir.root = parent->dir.root;
656 kernfs_addrm_start(&acxt);
657 rc = kernfs_add_one(&acxt, kn, parent);
658 kernfs_addrm_finish(&acxt);
667 static struct dentry *kernfs_iop_lookup(struct inode *dir,
668 struct dentry *dentry,
672 struct kernfs_node *parent = dentry->d_parent->d_fsdata;
673 struct kernfs_node *kn;
675 const void *ns = NULL;
677 mutex_lock(&kernfs_mutex);
679 if (kernfs_ns_enabled(parent))
680 ns = kernfs_info(dir->i_sb)->ns;
682 kn = kernfs_find_ns(parent, dentry->d_name.name, ns);
690 dentry->d_fsdata = kn;
692 /* attach dentry and inode */
693 inode = kernfs_get_inode(dir->i_sb, kn);
695 ret = ERR_PTR(-ENOMEM);
699 /* instantiate and hash dentry */
700 ret = d_materialise_unique(dentry, inode);
702 mutex_unlock(&kernfs_mutex);
706 static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry,
709 struct kernfs_node *parent = dir->i_private;
710 struct kernfs_dir_ops *kdops = kernfs_root(parent)->dir_ops;
712 if (!kdops || !kdops->mkdir)
715 return kdops->mkdir(parent, dentry->d_name.name, mode);
718 static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry)
720 struct kernfs_node *kn = dentry->d_fsdata;
721 struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops;
723 if (!kdops || !kdops->rmdir)
726 return kdops->rmdir(kn);
729 static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry,
730 struct inode *new_dir, struct dentry *new_dentry)
732 struct kernfs_node *kn = old_dentry->d_fsdata;
733 struct kernfs_node *new_parent = new_dir->i_private;
734 struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops;
736 if (!kdops || !kdops->rename)
739 return kdops->rename(kn, new_parent, new_dentry->d_name.name);
742 const struct inode_operations kernfs_dir_iops = {
743 .lookup = kernfs_iop_lookup,
744 .permission = kernfs_iop_permission,
745 .setattr = kernfs_iop_setattr,
746 .getattr = kernfs_iop_getattr,
747 .setxattr = kernfs_iop_setxattr,
748 .removexattr = kernfs_iop_removexattr,
749 .getxattr = kernfs_iop_getxattr,
750 .listxattr = kernfs_iop_listxattr,
752 .mkdir = kernfs_iop_mkdir,
753 .rmdir = kernfs_iop_rmdir,
754 .rename = kernfs_iop_rename,
757 static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos)
759 struct kernfs_node *last;
766 if (kernfs_type(pos) != KERNFS_DIR)
769 rbn = rb_first(&pos->dir.children);
780 * kernfs_next_descendant_post - find the next descendant for post-order walk
781 * @pos: the current position (%NULL to initiate traversal)
782 * @root: kernfs_node whose descendants to walk
784 * Find the next descendant to visit for post-order traversal of @root's
785 * descendants. @root is included in the iteration and the last node to be
788 static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos,
789 struct kernfs_node *root)
793 lockdep_assert_held(&kernfs_mutex);
795 /* if first iteration, visit leftmost descendant which may be root */
797 return kernfs_leftmost_descendant(root);
799 /* if we visited @root, we're done */
803 /* if there's an unvisited sibling, visit its leftmost descendant */
804 rbn = rb_next(&pos->rb);
806 return kernfs_leftmost_descendant(rb_to_kn(rbn));
808 /* no sibling left, visit parent */
812 static void __kernfs_remove(struct kernfs_addrm_cxt *acxt,
813 struct kernfs_node *kn)
815 struct kernfs_node *pos, *next;
820 pr_debug("kernfs %s: removing\n", kn->name);
825 next = kernfs_next_descendant_post(pos, kn);
827 kernfs_remove_one(acxt, pos);
832 * kernfs_remove - remove a kernfs_node recursively
833 * @kn: the kernfs_node to remove
835 * Remove @kn along with all its subdirectories and files.
837 void kernfs_remove(struct kernfs_node *kn)
839 struct kernfs_addrm_cxt acxt;
841 kernfs_addrm_start(&acxt);
842 __kernfs_remove(&acxt, kn);
843 kernfs_addrm_finish(&acxt);
847 * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it
848 * @parent: parent of the target
849 * @name: name of the kernfs_node to remove
850 * @ns: namespace tag of the kernfs_node to remove
852 * Look for the kernfs_node with @name and @ns under @parent and remove it.
853 * Returns 0 on success, -ENOENT if such entry doesn't exist.
855 int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name,
858 struct kernfs_addrm_cxt acxt;
859 struct kernfs_node *kn;
862 WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n",
867 kernfs_addrm_start(&acxt);
869 kn = kernfs_find_ns(parent, name, ns);
871 __kernfs_remove(&acxt, kn);
873 kernfs_addrm_finish(&acxt);
882 * kernfs_rename_ns - move and rename a kernfs_node
884 * @new_parent: new parent to put @sd under
885 * @new_name: new name
886 * @new_ns: new namespace tag
888 int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
889 const char *new_name, const void *new_ns)
893 mutex_lock(&kernfs_mutex);
896 if ((kn->flags | new_parent->flags) & KERNFS_REMOVED)
900 if ((kn->parent == new_parent) && (kn->ns == new_ns) &&
901 (strcmp(kn->name, new_name) == 0))
902 goto out; /* nothing to rename */
905 if (kernfs_find_ns(new_parent, new_name, new_ns))
908 /* rename kernfs_node */
909 if (strcmp(kn->name, new_name) != 0) {
911 new_name = kstrdup(new_name, GFP_KERNEL);
915 if (kn->flags & KERNFS_STATIC_NAME)
916 kn->flags &= ~KERNFS_STATIC_NAME;
924 * Move to the appropriate place in the appropriate directories rbtree.
926 kernfs_unlink_sibling(kn);
927 kernfs_get(new_parent);
928 kernfs_put(kn->parent);
930 kn->hash = kernfs_name_hash(kn->name, kn->ns);
931 kn->parent = new_parent;
932 kernfs_link_sibling(kn);
936 mutex_unlock(&kernfs_mutex);
940 /* Relationship between s_mode and the DT_xxx types */
941 static inline unsigned char dt_type(struct kernfs_node *kn)
943 return (kn->mode >> 12) & 15;
946 static int kernfs_dir_fop_release(struct inode *inode, struct file *filp)
948 kernfs_put(filp->private_data);
952 static struct kernfs_node *kernfs_dir_pos(const void *ns,
953 struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos)
956 int valid = !(pos->flags & KERNFS_REMOVED) &&
957 pos->parent == parent && hash == pos->hash;
962 if (!pos && (hash > 1) && (hash < INT_MAX)) {
963 struct rb_node *node = parent->dir.children.rb_node;
965 pos = rb_to_kn(node);
967 if (hash < pos->hash)
968 node = node->rb_left;
969 else if (hash > pos->hash)
970 node = node->rb_right;
975 /* Skip over entries in the wrong namespace */
976 while (pos && pos->ns != ns) {
977 struct rb_node *node = rb_next(&pos->rb);
981 pos = rb_to_kn(node);
986 static struct kernfs_node *kernfs_dir_next_pos(const void *ns,
987 struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos)
989 pos = kernfs_dir_pos(ns, parent, ino, pos);
992 struct rb_node *node = rb_next(&pos->rb);
996 pos = rb_to_kn(node);
997 } while (pos && pos->ns != ns);
1001 static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx)
1003 struct dentry *dentry = file->f_path.dentry;
1004 struct kernfs_node *parent = dentry->d_fsdata;
1005 struct kernfs_node *pos = file->private_data;
1006 const void *ns = NULL;
1008 if (!dir_emit_dots(file, ctx))
1010 mutex_lock(&kernfs_mutex);
1012 if (kernfs_ns_enabled(parent))
1013 ns = kernfs_info(dentry->d_sb)->ns;
1015 for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos);
1017 pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) {
1018 const char *name = pos->name;
1019 unsigned int type = dt_type(pos);
1020 int len = strlen(name);
1021 ino_t ino = pos->ino;
1023 ctx->pos = pos->hash;
1024 file->private_data = pos;
1027 mutex_unlock(&kernfs_mutex);
1028 if (!dir_emit(ctx, name, len, ino, type))
1030 mutex_lock(&kernfs_mutex);
1032 mutex_unlock(&kernfs_mutex);
1033 file->private_data = NULL;
1038 static loff_t kernfs_dir_fop_llseek(struct file *file, loff_t offset,
1041 struct inode *inode = file_inode(file);
1044 mutex_lock(&inode->i_mutex);
1045 ret = generic_file_llseek(file, offset, whence);
1046 mutex_unlock(&inode->i_mutex);
1051 const struct file_operations kernfs_dir_fops = {
1052 .read = generic_read_dir,
1053 .iterate = kernfs_fop_readdir,
1054 .release = kernfs_dir_fop_release,
1055 .llseek = kernfs_dir_fop_llseek,