diff options
Diffstat (limited to 'fs/sysfs/dir.c')
| -rw-r--r-- | fs/sysfs/dir.c | 1075 |
1 files changed, 35 insertions, 1040 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 5e73d6626e50..ee0d761c3179 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -13,465 +13,31 @@ #undef DEBUG #include <linux/fs.h> -#include <linux/mount.h> -#include <linux/module.h> #include <linux/kobject.h> -#include <linux/namei.h> -#include <linux/idr.h> -#include <linux/completion.h> -#include <linux/mutex.h> #include <linux/slab.h> -#include <linux/security.h> -#include <linux/hash.h> #include "sysfs.h" -DEFINE_MUTEX(sysfs_mutex); DEFINE_SPINLOCK(sysfs_symlink_target_lock); -#define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb) - -static DEFINE_SPINLOCK(sysfs_ino_lock); -static DEFINE_IDA(sysfs_ino_ida); - -/** - * sysfs_name_hash - * @name: Null terminated string to hash - * @ns: Namespace tag to hash - * - * Returns 31 bit hash of ns + name (so it fits in an off_t ) - */ -static unsigned int sysfs_name_hash(const char *name, const void *ns) -{ - unsigned long hash = init_name_hash(); - unsigned int len = strlen(name); - while (len--) - hash = partial_name_hash(*name++, hash); - hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31)); - hash &= 0x7fffffffU; - /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */ - if (hash < 1) - hash += 2; - if (hash >= INT_MAX) - hash = INT_MAX - 1; - return hash; -} - -static int sysfs_name_compare(unsigned int hash, const char *name, - const void *ns, const struct sysfs_dirent *sd) -{ - if (hash != sd->s_hash) - return hash - sd->s_hash; - if (ns != sd->s_ns) - return ns - sd->s_ns; - return strcmp(name, sd->s_name); -} - -static int sysfs_sd_compare(const struct sysfs_dirent *left, - const struct sysfs_dirent *right) -{ - return sysfs_name_compare(left->s_hash, left->s_name, left->s_ns, - right); -} - -/** - * sysfs_link_sibling - link sysfs_dirent into sibling rbtree - * @sd: sysfs_dirent of interest - * - * Link @sd into its sibling rbtree which starts from - * sd->s_parent->s_dir.children. - * - * Locking: - * mutex_lock(sysfs_mutex) - * - * RETURNS: - * 0 on susccess -EEXIST on failure. - */ -static int sysfs_link_sibling(struct sysfs_dirent *sd) -{ - struct rb_node **node = &sd->s_parent->s_dir.children.rb_node; - struct rb_node *parent = NULL; - - if (sysfs_type(sd) == SYSFS_DIR) - sd->s_parent->s_dir.subdirs++; - - while (*node) { - struct sysfs_dirent *pos; - int result; - - pos = to_sysfs_dirent(*node); - parent = *node; - result = sysfs_sd_compare(sd, pos); - if (result < 0) - node = &pos->s_rb.rb_left; - else if (result > 0) - node = &pos->s_rb.rb_right; - else - return -EEXIST; - } - /* add new node and rebalance the tree */ - rb_link_node(&sd->s_rb, parent, node); - rb_insert_color(&sd->s_rb, &sd->s_parent->s_dir.children); - return 0; -} - -/** - * sysfs_unlink_sibling - unlink sysfs_dirent from sibling rbtree - * @sd: sysfs_dirent of interest - * - * Unlink @sd from its sibling rbtree which starts from - * sd->s_parent->s_dir.children. - * - * Locking: - * mutex_lock(sysfs_mutex) - */ -static void sysfs_unlink_sibling(struct sysfs_dirent *sd) -{ - if (sysfs_type(sd) == SYSFS_DIR) - sd->s_parent->s_dir.subdirs--; - - rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children); -} - -/** - * sysfs_get_active - get an active reference to sysfs_dirent - * @sd: sysfs_dirent to get an active reference to - * - * Get an active reference of @sd. This function is noop if @sd - * is NULL. - * - * RETURNS: - * Pointer to @sd on success, NULL on failure. - */ -struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) -{ - if (unlikely(!sd)) - return NULL; - - if (!atomic_inc_unless_negative(&sd->s_active)) - return NULL; - - if (likely(!sysfs_ignore_lockdep(sd))) - rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); - return sd; -} - -/** - * sysfs_put_active - put an active reference to sysfs_dirent - * @sd: sysfs_dirent to put an active reference to - * - * Put an active reference to @sd. This function is noop if @sd - * is NULL. - */ -void sysfs_put_active(struct sysfs_dirent *sd) -{ - int v; - - if (unlikely(!sd)) - return; - - if (likely(!sysfs_ignore_lockdep(sd))) - rwsem_release(&sd->dep_map, 1, _RET_IP_); - v = atomic_dec_return(&sd->s_active); - if (likely(v != SD_DEACTIVATED_BIAS)) - return; - - /* atomic_dec_return() is a mb(), we'll always see the updated - * sd->u.completion. - */ - complete(sd->u.completion); -} - -/** - * sysfs_deactivate - deactivate sysfs_dirent - * @sd: sysfs_dirent to deactivate - * - * Deny new active references and drain existing ones. - */ -static void sysfs_deactivate(struct sysfs_dirent *sd) -{ - DECLARE_COMPLETION_ONSTACK(wait); - int v; - - BUG_ON(!(sd->s_flags & SYSFS_FLAG_REMOVED)); - - if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF)) - return; - - sd->u.completion = (void *)&wait; - - rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_); - /* atomic_add_return() is a mb(), put_active() will always see - * the updated sd->u.completion. - */ - v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active); - - if (v != SD_DEACTIVATED_BIAS) { - lock_contended(&sd->dep_map, _RET_IP_); - wait_for_completion(&wait); - } - - lock_acquired(&sd->dep_map, _RET_IP_); - rwsem_release(&sd->dep_map, 1, _RET_IP_); -} - -static int sysfs_alloc_ino(unsigned int *pino) -{ - int ino, rc; - - retry: - spin_lock(&sysfs_ino_lock); - rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino); - spin_unlock(&sysfs_ino_lock); - - if (rc == -EAGAIN) { - if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL)) - goto retry; - rc = -ENOMEM; - } - - *pino = ino; - return rc; -} - -static void sysfs_free_ino(unsigned int ino) -{ - spin_lock(&sysfs_ino_lock); - ida_remove(&sysfs_ino_ida, ino); - spin_unlock(&sysfs_ino_lock); -} - -void release_sysfs_dirent(struct sysfs_dirent *sd) -{ - struct sysfs_dirent *parent_sd; - - repeat: - /* Moving/renaming is always done while holding reference. - * sd->s_parent won't change beneath us. - */ - parent_sd = sd->s_parent; - - WARN(!(sd->s_flags & SYSFS_FLAG_REMOVED), - "sysfs: free using entry: %s/%s\n", - parent_sd ? parent_sd->s_name : "", sd->s_name); - - if (sysfs_type(sd) == SYSFS_KOBJ_LINK) - sysfs_put(sd->s_symlink.target_sd); - if (sysfs_type(sd) & SYSFS_COPY_NAME) - kfree(sd->s_name); - if (sd->s_iattr && sd->s_iattr->ia_secdata) - security_release_secctx(sd->s_iattr->ia_secdata, - sd->s_iattr->ia_secdata_len); - kfree(sd->s_iattr); - sysfs_free_ino(sd->s_ino); - kmem_cache_free(sysfs_dir_cachep, sd); - - sd = parent_sd; - if (sd && atomic_dec_and_test(&sd->s_count)) - goto repeat; -} - -static int sysfs_dentry_delete(const struct dentry *dentry) -{ - struct sysfs_dirent *sd = dentry->d_fsdata; - return !(sd && !(sd->s_flags & SYSFS_FLAG_REMOVED)); -} - -static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags) -{ - struct sysfs_dirent *sd; - int type; - - if (flags & LOOKUP_RCU) - return -ECHILD; - - sd = dentry->d_fsdata; - mutex_lock(&sysfs_mutex); - - /* The sysfs dirent has been deleted */ - if (sd->s_flags & SYSFS_FLAG_REMOVED) - goto out_bad; - - /* The sysfs dirent has been moved? */ - if (dentry->d_parent->d_fsdata != sd->s_parent) - goto out_bad; - - /* The sysfs dirent has been renamed */ - if (strcmp(dentry->d_name.name, sd->s_name) != 0) - goto out_bad; - - /* The sysfs dirent has been moved to a different namespace */ - type = KOBJ_NS_TYPE_NONE; - if (sd->s_parent) { - type = sysfs_ns_type(sd->s_parent); - if (type != KOBJ_NS_TYPE_NONE && - sysfs_info(dentry->d_sb)->ns[type] != sd->s_ns) - goto out_bad; - } - - mutex_unlock(&sysfs_mutex); -out_valid: - return 1; -out_bad: - /* Remove the dentry from the dcache hashes. - * If this is a deleted dentry we use d_drop instead of d_delete - * so sysfs doesn't need to cope with negative dentries. - * - * If this is a dentry that has simply been renamed we - * use d_drop to remove it from the dcache lookup on its - * old parent. If this dentry persists later when a lookup - * is performed at its new name the dentry will be readded - * to the dcache hashes. - */ - mutex_unlock(&sysfs_mutex); - - /* If we have submounts we must allow the vfs caches - * to lie about the state of the filesystem to prevent - * leaks and other nasty things. - */ - if (check_submounts_and_drop(dentry) != 0) - goto out_valid; - - return 0; -} - -static void sysfs_dentry_release(struct dentry *dentry) -{ - sysfs_put(dentry->d_fsdata); -} - -const struct dentry_operations sysfs_dentry_ops = { - .d_revalidate = sysfs_dentry_revalidate, - .d_delete = sysfs_dentry_delete, - .d_release = sysfs_dentry_release, -}; - -struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) -{ - char *dup_name = NULL; - struct sysfs_dirent *sd; - - if (type & SYSFS_COPY_NAME) { - name = dup_name = kstrdup(name, GFP_KERNEL); - if (!name) - return NULL; - } - - sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL); - if (!sd) - goto err_out1; - - if (sysfs_alloc_ino(&sd->s_ino)) - goto err_out2; - - atomic_set(&sd->s_count, 1); - atomic_set(&sd->s_active, 0); - - sd->s_name = name; - sd->s_mode = mode; - sd->s_flags = type | SYSFS_FLAG_REMOVED; - - return sd; - - err_out2: - kmem_cache_free(sysfs_dir_cachep, sd); - err_out1: - kfree(dup_name); - return NULL; -} - -/** - * sysfs_addrm_start - prepare for sysfs_dirent add/remove - * @acxt: pointer to sysfs_addrm_cxt to be used - * - * This function is called when the caller is about to add or remove - * sysfs_dirent. This function acquires sysfs_mutex. @acxt is used - * to keep and pass context to other addrm functions. - * - * LOCKING: - * Kernel thread context (may sleep). sysfs_mutex is locked on - * return. - */ -void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt) - __acquires(sysfs_mutex) -{ - memset(acxt, 0, sizeof(*acxt)); - - mutex_lock(&sysfs_mutex); -} - -/** - * __sysfs_add_one - add sysfs_dirent to parent without warning - * @acxt: addrm context to use - * @sd: sysfs_dirent to be added - * @parent_sd: the parent sysfs_dirent to add @sd to - * - * Get @parent_sd and set @sd->s_parent to it and increment nlink of - * the parent inode if @sd is a directory and link into the children - * list of the parent. - * - * This function should be called between calls to - * sysfs_addrm_start() and sysfs_addrm_finish() and should be - * passed the same @acxt as passed to sysfs_addrm_start(). - * - * LOCKING: - * Determined by sysfs_addrm_start(). - * - * RETURNS: - * 0 on success, -EEXIST if entry with the given name already - * exists. - */ -int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, - struct sysfs_dirent *parent_sd) -{ - struct sysfs_inode_attrs *ps_iattr; - int ret; - - if (!!sysfs_ns_type(parent_sd) != !!sd->s_ns) { - WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", - sysfs_ns_type(parent_sd) ? "required" : "invalid", - parent_sd->s_name, sd->s_name); - return -EINVAL; - } - - sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns); - sd->s_parent = sysfs_get(parent_sd); - - ret = sysfs_link_sibling(sd); - if (ret) - return ret; - - /* Update timestamps on the parent */ - ps_iattr = parent_sd->s_iattr; - if (ps_iattr) { - struct iattr *ps_iattrs = &ps_iattr->ia_iattr; - ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; - } - - /* Mark the entry added into directory tree */ - sd->s_flags &= ~SYSFS_FLAG_REMOVED; - - return 0; -} - /** * sysfs_pathname - return full path to sysfs dirent - * @sd: sysfs_dirent whose path we want + * @kn: kernfs_node whose path we want * @path: caller allocated buffer of size PATH_MAX * * Gives the name "/" to the sysfs_root entry; any path returned * is relative to wherever sysfs is mounted. */ -static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) +static char *sysfs_pathname(struct kernfs_node *kn, char *path) { - if (sd->s_parent) { - sysfs_pathname(sd->s_parent, path); + if (kn->parent) { + sysfs_pathname(kn->parent, path); strlcat(path, "/", PATH_MAX); } - strlcat(path, sd->s_name, PATH_MAX); + strlcat(path, kn->name, PATH_MAX); return path; } -void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name) +void sysfs_warn_dup(struct kernfs_node *parent, const char *name) { char *path; @@ -489,445 +55,34 @@ void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name) } /** - * sysfs_add_one - add sysfs_dirent to parent - * @acxt: addrm context to use - * @sd: sysfs_dirent to be added - * @parent_sd: the parent sysfs_dirent to add @sd to - * - * Get @parent_sd and set @sd->s_parent to it and increment nlink of - * the parent inode if @sd is a directory and link into the children - * list of the parent. - * - * This function should be called between calls to - * sysfs_addrm_start() and sysfs_addrm_finish() and should be - * passed the same @acxt as passed to sysfs_addrm_start(). - * - * LOCKING: - * Determined by sysfs_addrm_start(). - * - * RETURNS: - * 0 on success, -EEXIST if entry with the given name already - * exists. - */ -int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, - struct sysfs_dirent *parent_sd) -{ - int ret; - - ret = __sysfs_add_one(acxt, sd, parent_sd); - - if (ret == -EEXIST) - sysfs_warn_dup(parent_sd, sd->s_name); - return ret; -} - -/** - * sysfs_remove_one - remove sysfs_dirent from parent - * @acxt: addrm context to use - * @sd: sysfs_dirent to be removed - * - * Mark @sd removed and drop nlink of parent inode if @sd is a - * directory. @sd is unlinked from the children list. - * - * This function should be called between calls to - * sysfs_addrm_start() and sysfs_addrm_finish() and should be - * passed the same @acxt as passed to sysfs_addrm_start(). - * - * LOCKING: - * Determined by sysfs_addrm_start(). - */ -static void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, - struct sysfs_dirent *sd) -{ - struct sysfs_inode_attrs *ps_iattr; - - /* - * Removal can be called multiple times on the same node. Only the - * first invocation is effective and puts the base ref. - */ - if (sd->s_flags & SYSFS_FLAG_REMOVED) - return; - - sysfs_unlink_sibling(sd); - - /* Update timestamps on the parent */ - ps_iattr = sd->s_parent->s_iattr; - if (ps_iattr) { - struct iattr *ps_iattrs = &ps_iattr->ia_iattr; - ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; - } - - sd->s_flags |= SYSFS_FLAG_REMOVED; - sd->u.removed_list = acxt->removed; - acxt->removed = sd; -} - -/** - * sysfs_addrm_finish - finish up sysfs_dirent add/remove - * @acxt: addrm context to finish up - * - * Finish up sysfs_dirent add/remove. Resources acquired by - * sysfs_addrm_start() are released and removed sysfs_dirents are - * cleaned up. - * - * LOCKING: - * sysfs_mutex is released. - */ -void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) - __releases(sysfs_mutex) -{ - /* release resources acquired by sysfs_addrm_start() */ - mutex_unlock(&sysfs_mutex); - - /* kill removed sysfs_dirents */ - while (acxt->removed) { - struct sysfs_dirent *sd = acxt->removed; - - acxt->removed = sd->u.removed_list; - - sysfs_deactivate(sd); - sysfs_unmap_bin_file(sd); - sysfs_put(sd); - } -} - -/** - * sysfs_find_dirent - find sysfs_dirent with the given name - * @parent_sd: sysfs_dirent to search under - * @name: name to look for - * @ns: the namespace tag to use - * - * Look for sysfs_dirent with name @name under @parent_sd. - * - * LOCKING: - * mutex_lock(sysfs_mutex) - * - * RETURNS: - * Pointer to sysfs_dirent if found, NULL if not. - */ -struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, - const unsigned char *name, - const void *ns) -{ - struct rb_node *node = parent_sd->s_dir.children.rb_node; - unsigned int hash; - - if (!!sysfs_ns_type(parent_sd) != !!ns) { - WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", - sysfs_ns_type(parent_sd) ? "required" : "invalid", - parent_sd->s_name, name); - return NULL; - } - - hash = sysfs_name_hash(name, ns); - while (node) { - struct sysfs_dirent *sd; - int result; - - sd = to_sysfs_dirent(node); - result = sysfs_name_compare(hash, name, ns, sd); - if (result < 0) - node = node->rb_left; - else if (result > 0) - node = node->rb_right; - else - return sd; - } - return NULL; -} - -/** - * sysfs_get_dirent_ns - find and get sysfs_dirent with the given name - * @parent_sd: sysfs_dirent to search under - * @name: name to look for - * @ns: the namespace tag to use - * - * Look for sysfs_dirent with name @name under @parent_sd and get - * it if found. - * - * LOCKING: - * Kernel thread context (may sleep). Grabs sysfs_mutex. - * - * RETURNS: - * Pointer to sysfs_dirent if found, NULL if not. - */ -struct sysfs_dirent *sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd, - const unsigned char *name, - const void *ns) -{ - struct sysfs_dirent *sd; - - mutex_lock(&sysfs_mutex); - sd = sysfs_find_dirent(parent_sd, name, ns); - sysfs_get(sd); - mutex_unlock(&sysfs_mutex); - - return sd; -} -EXPORT_SYMBOL_GPL(sysfs_get_dirent_ns); - -static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, - enum kobj_ns_type type, - const char *name, const void *ns, - struct sysfs_dirent **p_sd) -{ - umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; - struct sysfs_addrm_cxt acxt; - struct sysfs_dirent *sd; - int rc; - - /* allocate */ - sd = sysfs_new_dirent(name, mode, SYSFS_DIR); - if (!sd) - return -ENOMEM; - - sd->s_flags |= (type << SYSFS_NS_TYPE_SHIFT); - sd->s_ns = ns; - sd->s_dir.kobj = kobj; - - /* link in */ - sysfs_addrm_start(&acxt); - rc = sysfs_add_one(&acxt, sd, parent_sd); - sysfs_addrm_finish(&acxt); - - if (rc == 0) - *p_sd = sd; - else - sysfs_put(sd); - - return rc; -} - -int sysfs_create_subdir(struct kobject *kobj, const char *name, - struct sysfs_dirent **p_sd) -{ - return create_dir(kobj, kobj->sd, - KOBJ_NS_TYPE_NONE, name, NULL, p_sd); -} - -/** - * sysfs_read_ns_type: return associated ns_type - * @kobj: the kobject being queried - * - * Each kobject can be tagged with exactly one namespace type - * (i.e. network or user). Return the ns_type associated with - * this object if any - */ -static enum kobj_ns_type sysfs_read_ns_type(struct kobject *kobj) -{ - const struct kobj_ns_type_operations *ops; - enum kobj_ns_type type; - - ops = kobj_child_ns_ops(kobj); - if (!ops) - return KOBJ_NS_TYPE_NONE; - - type = ops->type; - BUG_ON(type <= KOBJ_NS_TYPE_NONE); - BUG_ON(type >= KOBJ_NS_TYPES); - BUG_ON(!kobj_ns_type_registered(type)); - - return type; -} - -/** * sysfs_create_dir_ns - create a directory for an object with a namespace tag * @kobj: object we're creating directory for * @ns: the namespace tag to use */ int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) { - enum kobj_ns_type type; - struct sysfs_dirent *parent_sd, *sd; - int error = 0; + struct kernfs_node *parent, *kn; BUG_ON(!kobj); if (kobj->parent) - parent_sd = kobj->parent->sd; + parent = kobj->parent->sd; else - parent_sd = &sysfs_root; + parent = sysfs_root_kn; - if (!parent_sd) + if (!parent) return -ENOENT; - type = sysfs_read_ns_type(kobj); - - error = create_dir(kobj, parent_sd, type, kobject_name(kobj), ns, &sd); - if (!error) - kobj->sd = sd; - return error; -} - -static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry, - unsigned int flags) -{ - struct dentry *ret = NULL; - struct dentry *parent = dentry->d_parent; - struct sysfs_dirent *parent_sd = parent->d_fsdata; - struct sysfs_dirent *sd; - struct inode *inode; - enum kobj_ns_type type; - const void *ns; - - mutex_lock(&sysfs_mutex); - - type = sysfs_ns_type(parent_sd); - ns = sysfs_info(dir->i_sb)->ns[type]; - - sd = sysfs_find_dirent(parent_sd, dentry->d_name.name, ns); - - /* no such entry */ - if (!sd) { - ret = ERR_PTR(-ENOENT); - goto out_unlock; - } - dentry->d_fsdata = sysfs_get(sd); - - /* attach dentry and inode */ - inode = sysfs_get_inode(dir->i_sb, sd); - if (!inode) { - ret = ERR_PTR(-ENOMEM); - goto out_unlock; - } - - /* instantiate and hash dentry */ - ret = d_materialise_unique(dentry, inode); - out_unlock: - mutex_unlock(&sysfs_mutex); - return ret; -} - -const struct inode_operations sysfs_dir_inode_operations = { - .lookup = sysfs_lookup, - .permission = sysfs_permission, - .setattr = sysfs_setattr, - .getattr = sysfs_getattr, - .setxattr = sysfs_setxattr, -}; - -static struct sysfs_dirent *sysfs_leftmost_descendant(struct sysfs_dirent *pos) -{ - struct sysfs_dirent *last; - - while (true) { - struct rb_node *rbn; - - last = pos; - - if (sysfs_type(pos) != SYSFS_DIR) - break; - - rbn = rb_first(&pos->s_dir.children); - if (!rbn) - break; - - pos = to_sysfs_dirent(rbn); - } - - return last; -} - -/** - * sysfs_next_descendant_post - find the next descendant for post-order walk - * @pos: the current position (%NULL to initiate traversal) - * @root: sysfs_dirent whose descendants to walk - * - * Find the next descendant to visit for post-order traversal of @root's - * descendants. @root is included in the iteration and the last node to be - * visited. - */ -static struct sysfs_dirent *sysfs_next_descendant_post(struct sysfs_dirent *pos, - struct sysfs_dirent *root) -{ - struct rb_node *rbn; - - lockdep_assert_held(&sysfs_mutex); - - /* if first iteration, visit leftmost descendant which may be root */ - if (!pos) - return sysfs_leftmost_descendant(root); - - /* if we visited @root, we're done */ - if (pos == root) - return NULL; - - /* if there's an unvisited sibling, visit its leftmost descendant */ - rbn = rb_next(&pos->s_rb); - if (rbn) - return sysfs_leftmost_descendant(to_sysfs_dirent(rbn)); - - /* no sibling left, visit parent */ - return pos->s_parent; -} - -static void __sysfs_remove(struct sysfs_addrm_cxt *acxt, - struct sysfs_dirent *sd) -{ - struct sysfs_dirent *pos, *next; - - if (!sd) - return; - - pr_debug("sysfs %s: removing\n", sd->s_name); - - next = NULL; - do { - pos = next; - next = sysfs_next_descendant_post(pos, sd); - if (pos) - sysfs_remove_one(acxt, pos); - } while (next); -} - -/** - * sysfs_remove - remove a sysfs_dirent recursively - * @sd: the sysfs_dirent to remove - * - * Remove @sd along with all its subdirectories and files. - */ -void sysfs_remove(struct sysfs_dirent *sd) -{ - struct sysfs_addrm_cxt acxt; - - sysfs_addrm_start(&acxt); - __sysfs_remove(&acxt, sd); - sysfs_addrm_finish(&acxt); -} - -/** - * sysfs_hash_and_remove - find a sysfs_dirent by name and remove it - * @dir_sd: parent of the target - * @name: name of the sysfs_dirent to remove - * @ns: namespace tag of the sysfs_dirent to remove - * - * Look for the sysfs_dirent with @name and @ns under @dir_sd and remove - * it. Returns 0 on success, -ENOENT if such entry doesn't exist. - */ -int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name, - const void *ns) -{ - struct sysfs_addrm_cxt acxt; - struct sysfs_dirent *sd; - - if (!dir_sd) { - WARN(1, KERN_WARNING "sysfs: can not remove '%s', no directory\n", - name); - return -ENOENT; + kn = kernfs_create_dir_ns(parent, kobject_name(kobj), + S_IRWXU | S_IRUGO | S_IXUGO, kobj, ns); + if (IS_ERR(kn)) { + if (PTR_ERR(kn) == -EEXIST) + sysfs_warn_dup(parent, kobject_name(kobj)); + return PTR_ERR(kn); } - sysfs_addrm_start(&acxt); - - sd = sysfs_find_dirent(dir_sd, name, ns); - if (sd) - __sysfs_remove(&acxt, sd); - - sysfs_addrm_finish(&acxt); - - if (sd) - return 0; - else - return -ENOENT; + kobj->sd = kn; + return 0; } /** @@ -940,207 +95,47 @@ int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name, */ void sysfs_remove_dir(struct kobject *kobj) { - struct sysfs_dirent *sd = kobj->sd; + struct kernfs_node *kn = kobj->sd; /* * In general, kboject owner is responsible for ensuring removal * doesn't race with other operations and sysfs doesn't provide any * protection; however, when @kobj is used as a symlink target, the * symlinking entity usually doesn't own @kobj and thus has no - * control over removal. @kobj->sd may be removed anytime and - * symlink code may end up dereferencing an already freed sd. + * control over removal. @kobj->sd may be removed anytime + * and symlink code may end up dereferencing an already freed node. * - * sysfs_symlink_target_lock synchronizes @kobj->sd disassociation - * against symlink operations so that symlink code can safely - * dereference @kobj->sd. + * sysfs_symlink_target_lock synchronizes @kobj->sd + * disassociation against symlink operations so that symlink code + * can safely dereference @kobj->sd. */ spin_lock(&sysfs_symlink_target_lock); kobj->sd = NULL; spin_unlock(&sysfs_symlink_target_lock); - if (sd) { - WARN_ON_ONCE(sysfs_type(sd) != SYSFS_DIR); - sysfs_remove(sd); + if (kn) { + WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR); + kernfs_remove(kn); } } -int sysfs_rename(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent_sd, - const char *new_name, const void *new_ns) -{ - int error; - - mutex_lock(&sysfs_mutex); - - error = 0; - if ((sd->s_parent == new_parent_sd) && (sd->s_ns == new_ns) && - (strcmp(sd->s_name, new_name) == 0)) - goto out; /* nothing to rename */ - - error = -EEXIST; - if (sysfs_find_dirent(new_parent_sd, new_name, new_ns)) - goto out; - - /* rename sysfs_dirent */ - if (strcmp(sd->s_name, new_name) != 0) { - error = -ENOMEM; - new_name = kstrdup(new_name, GFP_KERNEL); - if (!new_name) - goto out; - - kfree(sd->s_name); - sd->s_name = new_name; - } - - /* - * Move to the appropriate place in the appropriate directories rbtree. - */ - sysfs_unlink_sibling(sd); - sysfs_get(new_parent_sd); - sysfs_put(sd->s_parent); - sd->s_ns = new_ns; - sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns); - sd->s_parent = new_parent_sd; - sysfs_link_sibling(sd); - - error = 0; - out: - mutex_unlock(&sysfs_mutex); - return error; -} - int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, const void *new_ns) { - struct sysfs_dirent *parent_sd = kobj->sd->s_parent; + struct kernfs_node *parent = kobj->sd->parent; - return sysfs_rename(kobj->sd, parent_sd, new_name, new_ns); + return kernfs_rename_ns(kobj->sd, parent, new_name, new_ns); } int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, const void *new_ns) { - struct sysfs_dirent *sd = kobj->sd; - struct sysfs_dirent *new_parent_sd; + struct kernfs_node *kn = kobj->sd; + struct kernfs_node *new_parent; - BUG_ON(!sd->s_parent); - new_parent_sd = new_parent_kobj && new_parent_kobj->sd ? - new_parent_kobj->sd : &sysfs_root; + BUG_ON(!kn->parent); + new_parent = new_parent_kobj && new_parent_kobj->sd ? + new_parent_kobj->sd : sysfs_root_kn; - return sysfs_rename(sd, new_parent_sd, sd->s_name, new_ns); + return kernfs_rename_ns(kn, new_parent, kn->name, new_ns); } - -/* Relationship between s_mode and the DT_xxx types */ -static inline unsigned char dt_type(struct sysfs_dirent *sd) -{ - return (sd->s_mode >> 12) & 15; -} - -static int sysfs_dir_release(struct inode *inode, struct file *filp) -{ - sysfs_put(filp->private_data); - return 0; -} - -static struct sysfs_dirent *sysfs_dir_pos(const void *ns, - struct sysfs_dirent *parent_sd, loff_t hash, struct sysfs_dirent *pos) -{ - if (pos) { - int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) && - pos->s_parent == parent_sd && - hash == pos->s_hash; - sysfs_put(pos); - if (!valid) - pos = NULL; - } - if (!pos && (hash > 1) && (hash < INT_MAX)) { - struct rb_node *node = parent_sd->s_dir.children.rb_node; - while (node) { - pos = to_sysfs_dirent(node); - - if (hash < pos->s_hash) - node = node->rb_left; - else if (hash > pos->s_hash) - node = node->rb_right; - else - break; - } - } - /* Skip over entries in the wrong namespace */ - while (pos && pos->s_ns != ns) { - struct rb_node *node = rb_next(&pos->s_rb); - if (!node) - pos = NULL; - else - pos = to_sysfs_dirent(node); - } - return pos; -} - -static struct sysfs_dirent *sysfs_dir_next_pos(const void *ns, - struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos) -{ - pos = sysfs_dir_pos(ns, parent_sd, ino, pos); - if (pos) - do { - struct rb_node *node = rb_next(&pos->s_rb); - if (!node) - pos = NULL; - else - pos = to_sysfs_dirent(node); - } while (pos && pos->s_ns != ns); - return pos; -} - -static int sysfs_readdir(struct file *file, struct dir_context *ctx) -{ - struct dentry *dentry = file->f_path.dentry; - struct sysfs_dirent *parent_sd = dentry->d_fsdata; - struct sysfs_dirent *pos = file->private_data; - enum kobj_ns_type type; - const void *ns; - - type = sysfs_ns_type(parent_sd); - ns = sysfs_info(dentry->d_sb)->ns[type]; - - if (!dir_emit_dots(file, ctx)) - return 0; - mutex_lock(&sysfs_mutex); - for (pos = sysfs_dir_pos(ns, parent_sd, ctx->pos, pos); - pos; - pos = sysfs_dir_next_pos(ns, parent_sd, ctx->pos, pos)) { - const char *name = pos->s_name; - unsigned int type = dt_type(pos); - int len = strlen(name); - ino_t ino = pos->s_ino; - ctx->pos = pos->s_hash; - file->private_data = sysfs_get(pos); - - mutex_unlock(&sysfs_mutex); - if (!dir_emit(ctx, name, len, ino, type)) - return 0; - mutex_lock(&sysfs_mutex); - } - mutex_unlock(&sysfs_mutex); - file->private_data = NULL; - ctx->pos = INT_MAX; - return 0; -} - -static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence) -{ - struct inode *inode = file_inode(file); - loff_t ret; - - mutex_lock(&inode->i_mutex); - ret = generic_file_llseek(file, offset, whence); - mutex_unlock(&inode->i_mutex); - - return ret; -} - -const struct file_operations sysfs_dir_operations = { - .read = generic_read_dir, - .iterate = sysfs_readdir, - .release = sysfs_dir_release, - .llseek = sysfs_dir_llseek, -}; |