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fs/kernfs/dir.c
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// SPDX-License-Identifier: GPL-2.0-only |
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/* * fs/kernfs/dir.c - kernfs directory implementation * * Copyright (c) 2001-3 Patrick Mochel * Copyright (c) 2007 SUSE Linux Products GmbH * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org> |
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*/ |
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#include <linux/sched.h> |
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#include <linux/fs.h> #include <linux/namei.h> #include <linux/idr.h> #include <linux/slab.h> #include <linux/security.h> #include <linux/hash.h> #include "kernfs-internal.h" |
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DEFINE_MUTEX(kernfs_mutex); |
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static DEFINE_SPINLOCK(kernfs_rename_lock); /* kn->parent and ->name */ static char kernfs_pr_cont_buf[PATH_MAX]; /* protected by rename_lock */ |
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static DEFINE_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */ |
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|
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#define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb) |
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|
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static bool kernfs_active(struct kernfs_node *kn) { lockdep_assert_held(&kernfs_mutex); return atomic_read(&kn->active) >= 0; } |
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static bool kernfs_lockdep(struct kernfs_node *kn) { #ifdef CONFIG_DEBUG_LOCK_ALLOC return kn->flags & KERNFS_LOCKDEP; #else return false; #endif } |
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static int kernfs_name_locked(struct kernfs_node *kn, char *buf, size_t buflen) { |
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if (!kn) return strlcpy(buf, "(null)", buflen); |
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return strlcpy(buf, kn->parent ? kn->name : "/", buflen); } |
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/* kernfs_node_depth - compute depth from @from to @to */ static size_t kernfs_depth(struct kernfs_node *from, struct kernfs_node *to) |
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{ |
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size_t depth = 0; |
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|
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while (to->parent && to != from) { depth++; to = to->parent; } return depth; } |
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|
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static struct kernfs_node *kernfs_common_ancestor(struct kernfs_node *a, struct kernfs_node *b) { size_t da, db; struct kernfs_root *ra = kernfs_root(a), *rb = kernfs_root(b); if (ra != rb) return NULL; da = kernfs_depth(ra->kn, a); db = kernfs_depth(rb->kn, b); while (da > db) { a = a->parent; da--; } while (db > da) { b = b->parent; db--; } /* worst case b and a will be the same at root */ while (b != a) { b = b->parent; a = a->parent; } return a; } /** * kernfs_path_from_node_locked - find a pseudo-absolute path to @kn_to, * where kn_from is treated as root of the path. * @kn_from: kernfs node which should be treated as root for the path * @kn_to: kernfs node to which path is needed * @buf: buffer to copy the path into * @buflen: size of @buf * * We need to handle couple of scenarios here: * [1] when @kn_from is an ancestor of @kn_to at some level * kn_from: /n1/n2/n3 * kn_to: /n1/n2/n3/n4/n5 * result: /n4/n5 * * [2] when @kn_from is on a different hierarchy and we need to find common * ancestor between @kn_from and @kn_to. * kn_from: /n1/n2/n3/n4 * kn_to: /n1/n2/n5 * result: /../../n5 * OR * kn_from: /n1/n2/n3/n4/n5 [depth=5] * kn_to: /n1/n2/n3 [depth=3] * result: /../.. * |
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* [3] when @kn_to is NULL result will be "(null)" * |
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* Returns the length of the full path. If the full length is equal to or * greater than @buflen, @buf contains the truncated path with the trailing * '\0'. On error, -errno is returned. |
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*/ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, struct kernfs_node *kn_from, char *buf, size_t buflen) { struct kernfs_node *kn, *common; const char parent_str[] = "/.."; |
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size_t depth_from, depth_to, len = 0; int i, j; |
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|
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if (!kn_to) return strlcpy(buf, "(null)", buflen); |
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if (!kn_from) kn_from = kernfs_root(kn_to)->kn; if (kn_from == kn_to) return strlcpy(buf, "/", buflen); |
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if (!buf) return -EINVAL; |
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common = kernfs_common_ancestor(kn_from, kn_to); if (WARN_ON(!common)) |
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return -EINVAL; |
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depth_to = kernfs_depth(common, kn_to); depth_from = kernfs_depth(common, kn_from); |
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buf[0] = '\0'; |
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for (i = 0; i < depth_from; i++) len += strlcpy(buf + len, parent_str, len < buflen ? buflen - len : 0); /* Calculate how many bytes we need for the rest */ |
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for (i = depth_to - 1; i >= 0; i--) { for (kn = kn_to, j = 0; j < i; j++) kn = kn->parent; len += strlcpy(buf + len, "/", len < buflen ? buflen - len : 0); len += strlcpy(buf + len, kn->name, len < buflen ? buflen - len : 0); |
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} |
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|
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return len; |
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} /** * kernfs_name - obtain the name of a given node * @kn: kernfs_node of interest * @buf: buffer to copy @kn's name into * @buflen: size of @buf * * Copies the name of @kn into @buf of @buflen bytes. The behavior is * similar to strlcpy(). It returns the length of @kn's name and if @buf * isn't long enough, it's filled upto @buflen-1 and nul terminated. * |
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* Fills buffer with "(null)" if @kn is NULL. * |
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* This function can be called from any context. */ int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen) { unsigned long flags; int ret; spin_lock_irqsave(&kernfs_rename_lock, flags); ret = kernfs_name_locked(kn, buf, buflen); spin_unlock_irqrestore(&kernfs_rename_lock, flags); return ret; } /** |
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* kernfs_path_from_node - build path of node @to relative to @from. * @from: parent kernfs_node relative to which we need to build the path * @to: kernfs_node of interest * @buf: buffer to copy @to's path into * @buflen: size of @buf * * Builds @to's path relative to @from in @buf. @from and @to must * be on the same kernfs-root. If @from is not parent of @to, then a relative * path (which includes '..'s) as needed to reach from @from to @to is * returned. * |
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* Returns the length of the full path. If the full length is equal to or * greater than @buflen, @buf contains the truncated path with the trailing * '\0'. On error, -errno is returned. |
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*/ int kernfs_path_from_node(struct kernfs_node *to, struct kernfs_node *from, char *buf, size_t buflen) { unsigned long flags; int ret; spin_lock_irqsave(&kernfs_rename_lock, flags); ret = kernfs_path_from_node_locked(to, from, buf, buflen); spin_unlock_irqrestore(&kernfs_rename_lock, flags); return ret; } EXPORT_SYMBOL_GPL(kernfs_path_from_node); /** |
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* pr_cont_kernfs_name - pr_cont name of a kernfs_node * @kn: kernfs_node of interest * * This function can be called from any context. */ void pr_cont_kernfs_name(struct kernfs_node *kn) { unsigned long flags; spin_lock_irqsave(&kernfs_rename_lock, flags); kernfs_name_locked(kn, kernfs_pr_cont_buf, sizeof(kernfs_pr_cont_buf)); pr_cont("%s", kernfs_pr_cont_buf); spin_unlock_irqrestore(&kernfs_rename_lock, flags); } /** * pr_cont_kernfs_path - pr_cont path of a kernfs_node * @kn: kernfs_node of interest * * This function can be called from any context. */ void pr_cont_kernfs_path(struct kernfs_node *kn) { unsigned long flags; |
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int sz; |
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spin_lock_irqsave(&kernfs_rename_lock, flags); |
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sz = kernfs_path_from_node_locked(kn, NULL, kernfs_pr_cont_buf, sizeof(kernfs_pr_cont_buf)); if (sz < 0) { pr_cont("(error)"); goto out; } if (sz >= sizeof(kernfs_pr_cont_buf)) { pr_cont("(name too long)"); goto out; } pr_cont("%s", kernfs_pr_cont_buf); |
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|
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out: |
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spin_unlock_irqrestore(&kernfs_rename_lock, flags); } /** * kernfs_get_parent - determine the parent node and pin it * @kn: kernfs_node of interest * * Determines @kn's parent, pins and returns it. This function can be * called from any context. */ struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn) { struct kernfs_node *parent; unsigned long flags; spin_lock_irqsave(&kernfs_rename_lock, flags); parent = kn->parent; kernfs_get(parent); spin_unlock_irqrestore(&kernfs_rename_lock, flags); return parent; } |
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/** |
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* kernfs_name_hash |
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* @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 ) */ |
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static unsigned int kernfs_name_hash(const char *name, const void *ns) |
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{ |
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unsigned long hash = init_name_hash(ns); |
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unsigned int len = strlen(name); while (len--) hash = partial_name_hash(*name++, hash); |
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hash = end_name_hash(hash); |
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hash &= 0x7fffffffU; /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */ |
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if (hash < 2) |
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hash += 2; if (hash >= INT_MAX) hash = INT_MAX - 1; return hash; } |
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static int kernfs_name_compare(unsigned int hash, const char *name, const void *ns, const struct kernfs_node *kn) |
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{ |
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if (hash < kn->hash) return -1; if (hash > kn->hash) return 1; if (ns < kn->ns) return -1; if (ns > kn->ns) return 1; |
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return strcmp(name, kn->name); |
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} |
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static int kernfs_sd_compare(const struct kernfs_node *left, const struct kernfs_node *right) |
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{ |
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return kernfs_name_compare(left->hash, left->name, left->ns, right); |
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} /** |
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* kernfs_link_sibling - link kernfs_node into sibling rbtree |
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* @kn: kernfs_node of interest |
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* |
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* Link @kn into its sibling rbtree which starts from |
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* @kn->parent->dir.children. |
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* * Locking: |
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* mutex_lock(kernfs_mutex) |
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* * RETURNS: * 0 on susccess -EEXIST on failure. */ |
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static int kernfs_link_sibling(struct kernfs_node *kn) |
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{ |
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struct rb_node **node = &kn->parent->dir.children.rb_node; |
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struct rb_node *parent = NULL; |
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while (*node) { |
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struct kernfs_node *pos; |
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int result; |
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pos = rb_to_kn(*node); |
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parent = *node; |
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result = kernfs_sd_compare(kn, pos); |
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if (result < 0) |
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node = &pos->rb.rb_left; |
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else if (result > 0) |
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node = &pos->rb.rb_right; |
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else return -EEXIST; } |
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|
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/* add new node and rebalance the tree */ |
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rb_link_node(&kn->rb, parent, node); rb_insert_color(&kn->rb, &kn->parent->dir.children); |
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/* successfully added, account subdir number */ if (kernfs_type(kn) == KERNFS_DIR) kn->parent->dir.subdirs++; |
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return 0; } /** |
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* kernfs_unlink_sibling - unlink kernfs_node from sibling rbtree |
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* @kn: kernfs_node of interest |
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* |
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* Try to unlink @kn from its sibling rbtree which starts from * kn->parent->dir.children. Returns %true if @kn was actually * removed, %false if @kn wasn't on the rbtree. |
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* * Locking: |
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* mutex_lock(kernfs_mutex) |
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*/ |
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static bool kernfs_unlink_sibling(struct kernfs_node *kn) |
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{ |
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if (RB_EMPTY_NODE(&kn->rb)) return false; |
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if (kernfs_type(kn) == KERNFS_DIR) |
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kn->parent->dir.subdirs--; |
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|
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rb_erase(&kn->rb, &kn->parent->dir.children); |
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RB_CLEAR_NODE(&kn->rb); return true; |
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} /** |
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* kernfs_get_active - get an active reference to kernfs_node |
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* @kn: kernfs_node to get an active reference to |
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* |
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* Get an active reference of @kn. This function is noop if @kn |
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* is NULL. * * RETURNS: |
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* Pointer to @kn on success, NULL on failure. |
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*/ |
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struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) |
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{ |
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if (unlikely(!kn)) |
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return NULL; |
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if (!atomic_inc_unless_negative(&kn->active)) return NULL; |
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|
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if (kernfs_lockdep(kn)) |
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rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_); return kn; |
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} /** |
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* kernfs_put_active - put an active reference to kernfs_node |
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* @kn: kernfs_node to put an active reference to |
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* |
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* Put an active reference to @kn. This function is noop if @kn |
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* is NULL. */ |
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void kernfs_put_active(struct kernfs_node *kn) |
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{ int v; |
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if (unlikely(!kn)) |
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return; |
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if (kernfs_lockdep(kn)) |
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rwsem_release(&kn->dep_map, 1, _RET_IP_); |
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v = atomic_dec_return(&kn->active); |
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if (likely(v != KN_DEACTIVATED_BIAS)) |
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return; |
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wake_up_all(&kernfs_root(kn)->deactivate_waitq); |
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} /** |
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* kernfs_drain - drain kernfs_node * @kn: kernfs_node to drain |
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* |
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* Drain existing usages and nuke all existing mmaps of @kn. Mutiple * removers may invoke this function concurrently on @kn and all will * return after draining is complete. |
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*/ |
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static void kernfs_drain(struct kernfs_node *kn) |
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__releases(&kernfs_mutex) __acquires(&kernfs_mutex) |
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{ |
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struct kernfs_root *root = kernfs_root(kn); |
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|
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lockdep_assert_held(&kernfs_mutex); |
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WARN_ON_ONCE(kernfs_active(kn)); |
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|
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mutex_unlock(&kernfs_mutex); |
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if (kernfs_lockdep(kn)) { |
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rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); if (atomic_read(&kn->active) != KN_DEACTIVATED_BIAS) lock_contended(&kn->dep_map, _RET_IP_); } |
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|
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/* but everyone should wait for draining */ |
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wait_event(root->deactivate_waitq, atomic_read(&kn->active) == KN_DEACTIVATED_BIAS); |
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|
182fd64b6 kernfs: remove KE... |
456 |
if (kernfs_lockdep(kn)) { |
a6607930b kernfs: make kern... |
457 458 459 |
lock_acquired(&kn->dep_map, _RET_IP_); rwsem_release(&kn->dep_map, 1, _RET_IP_); } |
35beab063 kernfs: restructu... |
460 |
|
0e67db2f9 kernfs: add kernf... |
461 |
kernfs_drain_open_files(kn); |
ccf02aaf8 kernfs: invoke ke... |
462 |
|
35beab063 kernfs: restructu... |
463 |
mutex_lock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
464 |
} |
fd7b9f7b9 sysfs, kernfs: mo... |
465 |
/** |
324a56e16 kernfs: s/sysfs_d... |
466 467 |
* kernfs_get - get a reference count on a kernfs_node * @kn: the target kernfs_node |
fd7b9f7b9 sysfs, kernfs: mo... |
468 |
*/ |
324a56e16 kernfs: s/sysfs_d... |
469 |
void kernfs_get(struct kernfs_node *kn) |
fd7b9f7b9 sysfs, kernfs: mo... |
470 |
{ |
324a56e16 kernfs: s/sysfs_d... |
471 |
if (kn) { |
adc5e8b58 kernfs: drop s_ p... |
472 473 |
WARN_ON(!atomic_read(&kn->count)); atomic_inc(&kn->count); |
fd7b9f7b9 sysfs, kernfs: mo... |
474 475 476 477 478 |
} } EXPORT_SYMBOL_GPL(kernfs_get); /** |
324a56e16 kernfs: s/sysfs_d... |
479 480 |
* kernfs_put - put a reference count on a kernfs_node * @kn: the target kernfs_node |
fd7b9f7b9 sysfs, kernfs: mo... |
481 |
* |
324a56e16 kernfs: s/sysfs_d... |
482 |
* Put a reference count of @kn and destroy it if it reached zero. |
fd7b9f7b9 sysfs, kernfs: mo... |
483 |
*/ |
324a56e16 kernfs: s/sysfs_d... |
484 |
void kernfs_put(struct kernfs_node *kn) |
fd7b9f7b9 sysfs, kernfs: mo... |
485 |
{ |
324a56e16 kernfs: s/sysfs_d... |
486 |
struct kernfs_node *parent; |
ba7443bc6 sysfs, kernfs: im... |
487 |
struct kernfs_root *root; |
fd7b9f7b9 sysfs, kernfs: mo... |
488 |
|
ba16b2846 kernfs: add an AP... |
489 490 491 492 |
/* * kernfs_node is freed with ->count 0, kernfs_find_and_get_node_by_ino * depends on this to filter reused stale node */ |
adc5e8b58 kernfs: drop s_ p... |
493 |
if (!kn || !atomic_dec_and_test(&kn->count)) |
fd7b9f7b9 sysfs, kernfs: mo... |
494 |
return; |
324a56e16 kernfs: s/sysfs_d... |
495 |
root = kernfs_root(kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
496 |
repeat: |
81c173cb5 kernfs: remove KE... |
497 498 |
/* * Moving/renaming is always done while holding reference. |
adc5e8b58 kernfs: drop s_ p... |
499 |
* kn->parent won't change beneath us. |
fd7b9f7b9 sysfs, kernfs: mo... |
500 |
*/ |
adc5e8b58 kernfs: drop s_ p... |
501 |
parent = kn->parent; |
fd7b9f7b9 sysfs, kernfs: mo... |
502 |
|
81c173cb5 kernfs: remove KE... |
503 504 505 506 |
WARN_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS, "kernfs_put: %s/%s: released with incorrect active_ref %d ", parent ? parent->name : "", kn->name, atomic_read(&kn->active)); |
324a56e16 kernfs: s/sysfs_d... |
507 |
|
df23fc39b kernfs: s/sysfs/k... |
508 |
if (kernfs_type(kn) == KERNFS_LINK) |
adc5e8b58 kernfs: drop s_ p... |
509 |
kernfs_put(kn->symlink.target_kn); |
dfeb0750b kernfs: remove KE... |
510 511 |
kfree_const(kn->name); |
adc5e8b58 kernfs: drop s_ p... |
512 |
if (kn->iattr) { |
adc5e8b58 kernfs: drop s_ p... |
513 |
simple_xattrs_free(&kn->iattr->xattrs); |
26e28d68b kernfs: Allocatin... |
514 |
kmem_cache_free(kernfs_iattrs_cache, kn->iattr); |
2322392b0 kernfs: implement... |
515 |
} |
7d35079f8 kernfs: use idr i... |
516 |
spin_lock(&kernfs_idr_lock); |
c53cd490b kernfs: introduce... |
517 |
idr_remove(&root->ino_idr, kn->id.ino); |
7d35079f8 kernfs: use idr i... |
518 |
spin_unlock(&kernfs_idr_lock); |
a797bfc30 kernfs: s/sysfs/k... |
519 |
kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
520 |
|
324a56e16 kernfs: s/sysfs_d... |
521 522 |
kn = parent; if (kn) { |
adc5e8b58 kernfs: drop s_ p... |
523 |
if (atomic_dec_and_test(&kn->count)) |
ba7443bc6 sysfs, kernfs: im... |
524 525 |
goto repeat; } else { |
324a56e16 kernfs: s/sysfs_d... |
526 |
/* just released the root kn, free @root too */ |
7d35079f8 kernfs: use idr i... |
527 |
idr_destroy(&root->ino_idr); |
ba7443bc6 sysfs, kernfs: im... |
528 529 |
kfree(root); } |
fd7b9f7b9 sysfs, kernfs: mo... |
530 531 |
} EXPORT_SYMBOL_GPL(kernfs_put); |
c637b8acb kernfs: s/sysfs/k... |
532 |
static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags) |
fd7b9f7b9 sysfs, kernfs: mo... |
533 |
{ |
324a56e16 kernfs: s/sysfs_d... |
534 |
struct kernfs_node *kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
535 536 537 |
if (flags & LOOKUP_RCU) return -ECHILD; |
19bbb9262 kernfs: allow neg... |
538 |
/* Always perform fresh lookup for negatives */ |
2b0143b5c VFS: normal files... |
539 |
if (d_really_is_negative(dentry)) |
19bbb9262 kernfs: allow neg... |
540 |
goto out_bad_unlocked; |
319ba91d3 kernfs: don't set... |
541 |
kn = kernfs_dentry_node(dentry); |
a797bfc30 kernfs: s/sysfs/k... |
542 |
mutex_lock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
543 |
|
81c173cb5 kernfs: remove KE... |
544 545 |
/* The kernfs node has been deactivated */ if (!kernfs_active(kn)) |
fd7b9f7b9 sysfs, kernfs: mo... |
546 |
goto out_bad; |
c637b8acb kernfs: s/sysfs/k... |
547 |
/* The kernfs node has been moved? */ |
319ba91d3 kernfs: don't set... |
548 |
if (kernfs_dentry_node(dentry->d_parent) != kn->parent) |
fd7b9f7b9 sysfs, kernfs: mo... |
549 |
goto out_bad; |
c637b8acb kernfs: s/sysfs/k... |
550 |
/* The kernfs node has been renamed */ |
adc5e8b58 kernfs: drop s_ p... |
551 |
if (strcmp(dentry->d_name.name, kn->name) != 0) |
fd7b9f7b9 sysfs, kernfs: mo... |
552 |
goto out_bad; |
c637b8acb kernfs: s/sysfs/k... |
553 |
/* The kernfs node has been moved to a different namespace */ |
adc5e8b58 kernfs: drop s_ p... |
554 |
if (kn->parent && kernfs_ns_enabled(kn->parent) && |
c525aaddc kernfs: s/sysfs/k... |
555 |
kernfs_info(dentry->d_sb)->ns != kn->ns) |
fd7b9f7b9 sysfs, kernfs: mo... |
556 |
goto out_bad; |
a797bfc30 kernfs: s/sysfs/k... |
557 |
mutex_unlock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
558 559 |
return 1; out_bad: |
a797bfc30 kernfs: s/sysfs/k... |
560 |
mutex_unlock(&kernfs_mutex); |
19bbb9262 kernfs: allow neg... |
561 |
out_bad_unlocked: |
fd7b9f7b9 sysfs, kernfs: mo... |
562 563 |
return 0; } |
a797bfc30 kernfs: s/sysfs/k... |
564 |
const struct dentry_operations kernfs_dops = { |
c637b8acb kernfs: s/sysfs/k... |
565 |
.d_revalidate = kernfs_dop_revalidate, |
fd7b9f7b9 sysfs, kernfs: mo... |
566 |
}; |
0c23b2259 kernfs: implement... |
567 568 569 570 571 572 573 574 575 576 577 578 579 |
/** * kernfs_node_from_dentry - determine kernfs_node associated with a dentry * @dentry: the dentry in question * * Return the kernfs_node associated with @dentry. If @dentry is not a * kernfs one, %NULL is returned. * * While the returned kernfs_node will stay accessible as long as @dentry * is accessible, the returned node can be in any state and the caller is * fully responsible for determining what's accessible. */ struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry) { |
319ba91d3 kernfs: don't set... |
580 581 582 |
if (dentry->d_sb->s_op == &kernfs_sops && !d_really_is_negative(dentry)) return kernfs_dentry_node(dentry); |
0c23b2259 kernfs: implement... |
583 584 |
return NULL; } |
db4aad209 kernfs: associate... |
585 |
static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, |
e19dfdc83 kernfs: initializ... |
586 |
struct kernfs_node *parent, |
db4aad209 kernfs: associate... |
587 |
const char *name, umode_t mode, |
488dee96b kernfs: allow cre... |
588 |
kuid_t uid, kgid_t gid, |
db4aad209 kernfs: associate... |
589 |
unsigned flags) |
fd7b9f7b9 sysfs, kernfs: mo... |
590 |
{ |
324a56e16 kernfs: s/sysfs_d... |
591 |
struct kernfs_node *kn; |
4a3ef68ac kernfs: implement... |
592 |
u32 gen; |
bc755553d sysfs, kernfs: ma... |
593 |
int ret; |
fd7b9f7b9 sysfs, kernfs: mo... |
594 |
|
dfeb0750b kernfs: remove KE... |
595 596 597 |
name = kstrdup_const(name, GFP_KERNEL); if (!name) return NULL; |
fd7b9f7b9 sysfs, kernfs: mo... |
598 |
|
a797bfc30 kernfs: s/sysfs/k... |
599 |
kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL); |
324a56e16 kernfs: s/sysfs_d... |
600 |
if (!kn) |
fd7b9f7b9 sysfs, kernfs: mo... |
601 |
goto err_out1; |
7d35079f8 kernfs: use idr i... |
602 603 |
idr_preload(GFP_KERNEL); spin_lock(&kernfs_idr_lock); |
4a3ef68ac kernfs: implement... |
604 |
ret = idr_alloc_cyclic(&root->ino_idr, kn, 1, 0, GFP_ATOMIC); |
01e7ab5b9 kernfs: fix ino w... |
605 |
if (ret >= 0 && ret < root->last_ino) |
4a3ef68ac kernfs: implement... |
606 607 |
root->next_generation++; gen = root->next_generation; |
01e7ab5b9 kernfs: fix ino w... |
608 |
root->last_ino = ret; |
7d35079f8 kernfs: use idr i... |
609 610 |
spin_unlock(&kernfs_idr_lock); idr_preload_end(); |
bc755553d sysfs, kernfs: ma... |
611 |
if (ret < 0) |
fd7b9f7b9 sysfs, kernfs: mo... |
612 |
goto err_out2; |
c53cd490b kernfs: introduce... |
613 614 |
kn->id.ino = ret; kn->id.generation = gen; |
fd7b9f7b9 sysfs, kernfs: mo... |
615 |
|
ba16b2846 kernfs: add an AP... |
616 |
/* |
998267900 kernfs: fix barri... |
617 |
* set ino first. This RELEASE is paired with atomic_inc_not_zero in |
ba16b2846 kernfs: add an AP... |
618 619 |
* kernfs_find_and_get_node_by_ino */ |
998267900 kernfs: fix barri... |
620 |
atomic_set_release(&kn->count, 1); |
81c173cb5 kernfs: remove KE... |
621 |
atomic_set(&kn->active, KN_DEACTIVATED_BIAS); |
35beab063 kernfs: restructu... |
622 |
RB_CLEAR_NODE(&kn->rb); |
fd7b9f7b9 sysfs, kernfs: mo... |
623 |
|
adc5e8b58 kernfs: drop s_ p... |
624 625 |
kn->name = name; kn->mode = mode; |
81c173cb5 kernfs: remove KE... |
626 |
kn->flags = flags; |
fd7b9f7b9 sysfs, kernfs: mo... |
627 |
|
488dee96b kernfs: allow cre... |
628 629 630 631 632 633 634 635 636 637 638 |
if (!uid_eq(uid, GLOBAL_ROOT_UID) || !gid_eq(gid, GLOBAL_ROOT_GID)) { struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID, .ia_uid = uid, .ia_gid = gid, }; ret = __kernfs_setattr(kn, &iattr); if (ret < 0) goto err_out3; } |
e19dfdc83 kernfs: initializ... |
639 640 641 642 643 |
if (parent) { ret = security_kernfs_init_security(parent, kn); if (ret) goto err_out3; } |
324a56e16 kernfs: s/sysfs_d... |
644 |
return kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
645 |
|
488dee96b kernfs: allow cre... |
646 647 |
err_out3: idr_remove(&root->ino_idr, kn->id.ino); |
fd7b9f7b9 sysfs, kernfs: mo... |
648 |
err_out2: |
a797bfc30 kernfs: s/sysfs/k... |
649 |
kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
650 |
err_out1: |
dfeb0750b kernfs: remove KE... |
651 |
kfree_const(name); |
fd7b9f7b9 sysfs, kernfs: mo... |
652 653 |
return NULL; } |
db4aad209 kernfs: associate... |
654 655 |
struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, const char *name, umode_t mode, |
488dee96b kernfs: allow cre... |
656 |
kuid_t uid, kgid_t gid, |
db4aad209 kernfs: associate... |
657 658 659 |
unsigned flags) { struct kernfs_node *kn; |
e19dfdc83 kernfs: initializ... |
660 |
kn = __kernfs_new_node(kernfs_root(parent), parent, |
488dee96b kernfs: allow cre... |
661 |
name, mode, uid, gid, flags); |
db4aad209 kernfs: associate... |
662 663 664 665 666 667 |
if (kn) { kernfs_get(parent); kn->parent = parent; } return kn; } |
ba16b2846 kernfs: add an AP... |
668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 |
/* * kernfs_find_and_get_node_by_ino - get kernfs_node from inode number * @root: the kernfs root * @ino: inode number * * RETURNS: * NULL on failure. Return a kernfs node with reference counter incremented */ struct kernfs_node *kernfs_find_and_get_node_by_ino(struct kernfs_root *root, unsigned int ino) { struct kernfs_node *kn; rcu_read_lock(); kn = idr_find(&root->ino_idr, ino); if (!kn) goto out; /* * Since kernfs_node is freed in RCU, it's possible an old node for ino * is freed, but reused before RCU grace period. But a freed node (see * kernfs_put) or an incompletedly initialized node (see * __kernfs_new_node) should have 'count' 0. We can use this fact to * filter out such node. */ if (!atomic_inc_not_zero(&kn->count)) { kn = NULL; goto out; } /* * The node could be a new node or a reused node. If it's a new node, * we are ok. If it's reused because of RCU (because of * SLAB_TYPESAFE_BY_RCU), the __kernfs_new_node always sets its 'ino' * before 'count'. So if 'count' is uptodate, 'ino' should be uptodate, * hence we can use 'ino' to filter stale node. */ |
c53cd490b kernfs: introduce... |
705 |
if (kn->id.ino != ino) |
ba16b2846 kernfs: add an AP... |
706 707 708 709 710 711 712 713 714 |
goto out; rcu_read_unlock(); return kn; out: rcu_read_unlock(); kernfs_put(kn); return NULL; } |
fd7b9f7b9 sysfs, kernfs: mo... |
715 |
/** |
c637b8acb kernfs: s/sysfs/k... |
716 |
* kernfs_add_one - add kernfs_node to parent without warning |
324a56e16 kernfs: s/sysfs_d... |
717 |
* @kn: kernfs_node to be added |
fd7b9f7b9 sysfs, kernfs: mo... |
718 |
* |
db4aad209 kernfs: associate... |
719 720 721 |
* The caller must already have initialized @kn->parent. This * function increments nlink of the parent's inode if @kn is a * directory and link into the children list of the parent. |
fd7b9f7b9 sysfs, kernfs: mo... |
722 |
* |
fd7b9f7b9 sysfs, kernfs: mo... |
723 724 725 726 |
* RETURNS: * 0 on success, -EEXIST if entry with the given name already * exists. */ |
988cd7afb kernfs: remove ke... |
727 |
int kernfs_add_one(struct kernfs_node *kn) |
fd7b9f7b9 sysfs, kernfs: mo... |
728 |
{ |
db4aad209 kernfs: associate... |
729 |
struct kernfs_node *parent = kn->parent; |
c525aaddc kernfs: s/sysfs/k... |
730 |
struct kernfs_iattrs *ps_iattr; |
988cd7afb kernfs: remove ke... |
731 |
bool has_ns; |
fd7b9f7b9 sysfs, kernfs: mo... |
732 |
int ret; |
988cd7afb kernfs: remove ke... |
733 734 735 736 737 738 739 740 |
mutex_lock(&kernfs_mutex); ret = -EINVAL; has_ns = kernfs_ns_enabled(parent); if (WARN(has_ns != (bool)kn->ns, KERN_WARNING "kernfs: ns %s in '%s' for '%s' ", has_ns ? "required" : "invalid", parent->name, kn->name)) goto out_unlock; |
fd7b9f7b9 sysfs, kernfs: mo... |
741 |
|
df23fc39b kernfs: s/sysfs/k... |
742 |
if (kernfs_type(parent) != KERNFS_DIR) |
988cd7afb kernfs: remove ke... |
743 |
goto out_unlock; |
fd7b9f7b9 sysfs, kernfs: mo... |
744 |
|
988cd7afb kernfs: remove ke... |
745 |
ret = -ENOENT; |
ea015218f kernfs: Add suppo... |
746 747 |
if (parent->flags & KERNFS_EMPTY_DIR) goto out_unlock; |
d35258ef7 kernfs: allow nod... |
748 |
if ((parent->flags & KERNFS_ACTIVATED) && !kernfs_active(parent)) |
988cd7afb kernfs: remove ke... |
749 |
goto out_unlock; |
798c75a0d Revert "kernfs: r... |
750 |
|
c637b8acb kernfs: s/sysfs/k... |
751 |
kn->hash = kernfs_name_hash(kn->name, kn->ns); |
fd7b9f7b9 sysfs, kernfs: mo... |
752 |
|
c637b8acb kernfs: s/sysfs/k... |
753 |
ret = kernfs_link_sibling(kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
754 |
if (ret) |
988cd7afb kernfs: remove ke... |
755 |
goto out_unlock; |
fd7b9f7b9 sysfs, kernfs: mo... |
756 757 |
/* Update timestamps on the parent */ |
adc5e8b58 kernfs: drop s_ p... |
758 |
ps_iattr = parent->iattr; |
fd7b9f7b9 sysfs, kernfs: mo... |
759 |
if (ps_iattr) { |
058952196 kernfs: clean up ... |
760 761 |
ktime_get_real_ts64(&ps_iattr->ia_ctime); ps_iattr->ia_mtime = ps_iattr->ia_ctime; |
fd7b9f7b9 sysfs, kernfs: mo... |
762 |
} |
d35258ef7 kernfs: allow nod... |
763 764 765 766 767 768 769 770 771 772 773 774 |
mutex_unlock(&kernfs_mutex); /* * Activate the new node unless CREATE_DEACTIVATED is requested. * If not activated here, the kernfs user is responsible for * activating the node with kernfs_activate(). A node which hasn't * been activated is not visible to userland and its removal won't * trigger deactivation. */ if (!(kernfs_root(kn)->flags & KERNFS_ROOT_CREATE_DEACTIVATED)) kernfs_activate(kn); return 0; |
988cd7afb kernfs: remove ke... |
775 |
out_unlock: |
a797bfc30 kernfs: s/sysfs/k... |
776 |
mutex_unlock(&kernfs_mutex); |
988cd7afb kernfs: remove ke... |
777 |
return ret; |
fd7b9f7b9 sysfs, kernfs: mo... |
778 779 780 |
} /** |
324a56e16 kernfs: s/sysfs_d... |
781 782 |
* kernfs_find_ns - find kernfs_node with the given name * @parent: kernfs_node to search under |
fd7b9f7b9 sysfs, kernfs: mo... |
783 784 785 |
* @name: name to look for * @ns: the namespace tag to use * |
324a56e16 kernfs: s/sysfs_d... |
786 787 |
* Look for kernfs_node with name @name under @parent. Returns pointer to * the found kernfs_node on success, %NULL on failure. |
fd7b9f7b9 sysfs, kernfs: mo... |
788 |
*/ |
324a56e16 kernfs: s/sysfs_d... |
789 790 791 |
static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, const unsigned char *name, const void *ns) |
fd7b9f7b9 sysfs, kernfs: mo... |
792 |
{ |
adc5e8b58 kernfs: drop s_ p... |
793 |
struct rb_node *node = parent->dir.children.rb_node; |
ac9bba031 sysfs, kernfs: im... |
794 |
bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b9 sysfs, kernfs: mo... |
795 |
unsigned int hash; |
a797bfc30 kernfs: s/sysfs/k... |
796 |
lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
797 798 |
if (has_ns != (bool)ns) { |
c637b8acb kernfs: s/sysfs/k... |
799 800 |
WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s' ", |
adc5e8b58 kernfs: drop s_ p... |
801 |
has_ns ? "required" : "invalid", parent->name, name); |
fd7b9f7b9 sysfs, kernfs: mo... |
802 803 |
return NULL; } |
c637b8acb kernfs: s/sysfs/k... |
804 |
hash = kernfs_name_hash(name, ns); |
fd7b9f7b9 sysfs, kernfs: mo... |
805 |
while (node) { |
324a56e16 kernfs: s/sysfs_d... |
806 |
struct kernfs_node *kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
807 |
int result; |
324a56e16 kernfs: s/sysfs_d... |
808 |
kn = rb_to_kn(node); |
c637b8acb kernfs: s/sysfs/k... |
809 |
result = kernfs_name_compare(hash, name, ns, kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
810 811 812 813 814 |
if (result < 0) node = node->rb_left; else if (result > 0) node = node->rb_right; else |
324a56e16 kernfs: s/sysfs_d... |
815 |
return kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
816 817 818 |
} return NULL; } |
bd96f76a2 kernfs: implement... |
819 820 821 822 |
static struct kernfs_node *kernfs_walk_ns(struct kernfs_node *parent, const unsigned char *path, const void *ns) { |
e56ed358a kernfs: make kern... |
823 824 |
size_t len; char *p, *name; |
bd96f76a2 kernfs: implement... |
825 826 |
lockdep_assert_held(&kernfs_mutex); |
e56ed358a kernfs: make kern... |
827 828 829 830 831 832 833 |
/* grab kernfs_rename_lock to piggy back on kernfs_pr_cont_buf */ spin_lock_irq(&kernfs_rename_lock); len = strlcpy(kernfs_pr_cont_buf, path, sizeof(kernfs_pr_cont_buf)); if (len >= sizeof(kernfs_pr_cont_buf)) { spin_unlock_irq(&kernfs_rename_lock); |
bd96f76a2 kernfs: implement... |
834 |
return NULL; |
e56ed358a kernfs: make kern... |
835 836 837 |
} p = kernfs_pr_cont_buf; |
bd96f76a2 kernfs: implement... |
838 839 840 841 842 843 |
while ((name = strsep(&p, "/")) && parent) { if (*name == '\0') continue; parent = kernfs_find_ns(parent, name, ns); } |
e56ed358a kernfs: make kern... |
844 |
spin_unlock_irq(&kernfs_rename_lock); |
bd96f76a2 kernfs: implement... |
845 846 |
return parent; } |
fd7b9f7b9 sysfs, kernfs: mo... |
847 |
/** |
324a56e16 kernfs: s/sysfs_d... |
848 849 |
* kernfs_find_and_get_ns - find and get kernfs_node with the given name * @parent: kernfs_node to search under |
fd7b9f7b9 sysfs, kernfs: mo... |
850 851 852 |
* @name: name to look for * @ns: the namespace tag to use * |
324a56e16 kernfs: s/sysfs_d... |
853 |
* Look for kernfs_node with name @name under @parent and get a reference |
fd7b9f7b9 sysfs, kernfs: mo... |
854 |
* if found. This function may sleep and returns pointer to the found |
324a56e16 kernfs: s/sysfs_d... |
855 |
* kernfs_node on success, %NULL on failure. |
fd7b9f7b9 sysfs, kernfs: mo... |
856 |
*/ |
324a56e16 kernfs: s/sysfs_d... |
857 858 |
struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, const char *name, const void *ns) |
fd7b9f7b9 sysfs, kernfs: mo... |
859 |
{ |
324a56e16 kernfs: s/sysfs_d... |
860 |
struct kernfs_node *kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
861 |
|
a797bfc30 kernfs: s/sysfs/k... |
862 |
mutex_lock(&kernfs_mutex); |
324a56e16 kernfs: s/sysfs_d... |
863 864 |
kn = kernfs_find_ns(parent, name, ns); kernfs_get(kn); |
a797bfc30 kernfs: s/sysfs/k... |
865 |
mutex_unlock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
866 |
|
324a56e16 kernfs: s/sysfs_d... |
867 |
return kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
868 869 870 871 |
} EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); /** |
bd96f76a2 kernfs: implement... |
872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 |
* kernfs_walk_and_get_ns - find and get kernfs_node with the given path * @parent: kernfs_node to search under * @path: path to look for * @ns: the namespace tag to use * * Look for kernfs_node with path @path under @parent and get a reference * if found. This function may sleep and returns pointer to the found * kernfs_node on success, %NULL on failure. */ struct kernfs_node *kernfs_walk_and_get_ns(struct kernfs_node *parent, const char *path, const void *ns) { struct kernfs_node *kn; mutex_lock(&kernfs_mutex); kn = kernfs_walk_ns(parent, path, ns); kernfs_get(kn); mutex_unlock(&kernfs_mutex); return kn; } /** |
ba7443bc6 sysfs, kernfs: im... |
895 |
* kernfs_create_root - create a new kernfs hierarchy |
90c07c895 kernfs: rename ke... |
896 |
* @scops: optional syscall operations for the hierarchy |
d35258ef7 kernfs: allow nod... |
897 |
* @flags: KERNFS_ROOT_* flags |
ba7443bc6 sysfs, kernfs: im... |
898 899 900 901 902 |
* @priv: opaque data associated with the new directory * * Returns the root of the new hierarchy on success, ERR_PTR() value on * failure. */ |
90c07c895 kernfs: rename ke... |
903 |
struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops, |
d35258ef7 kernfs: allow nod... |
904 |
unsigned int flags, void *priv) |
ba7443bc6 sysfs, kernfs: im... |
905 906 |
{ struct kernfs_root *root; |
324a56e16 kernfs: s/sysfs_d... |
907 |
struct kernfs_node *kn; |
ba7443bc6 sysfs, kernfs: im... |
908 909 910 911 |
root = kzalloc(sizeof(*root), GFP_KERNEL); if (!root) return ERR_PTR(-ENOMEM); |
7d35079f8 kernfs: use idr i... |
912 |
idr_init(&root->ino_idr); |
7d568a838 kernfs: implement... |
913 |
INIT_LIST_HEAD(&root->supers); |
4a3ef68ac kernfs: implement... |
914 |
root->next_generation = 1; |
bc755553d sysfs, kernfs: ma... |
915 |
|
e19dfdc83 kernfs: initializ... |
916 |
kn = __kernfs_new_node(root, NULL, "", S_IFDIR | S_IRUGO | S_IXUGO, |
488dee96b kernfs: allow cre... |
917 |
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, |
db4aad209 kernfs: associate... |
918 |
KERNFS_DIR); |
324a56e16 kernfs: s/sysfs_d... |
919 |
if (!kn) { |
7d35079f8 kernfs: use idr i... |
920 |
idr_destroy(&root->ino_idr); |
ba7443bc6 sysfs, kernfs: im... |
921 922 923 |
kfree(root); return ERR_PTR(-ENOMEM); } |
324a56e16 kernfs: s/sysfs_d... |
924 |
kn->priv = priv; |
adc5e8b58 kernfs: drop s_ p... |
925 |
kn->dir.root = root; |
ba7443bc6 sysfs, kernfs: im... |
926 |
|
90c07c895 kernfs: rename ke... |
927 |
root->syscall_ops = scops; |
d35258ef7 kernfs: allow nod... |
928 |
root->flags = flags; |
324a56e16 kernfs: s/sysfs_d... |
929 |
root->kn = kn; |
abd54f028 kernfs: replace k... |
930 |
init_waitqueue_head(&root->deactivate_waitq); |
ba7443bc6 sysfs, kernfs: im... |
931 |
|
d35258ef7 kernfs: allow nod... |
932 933 |
if (!(root->flags & KERNFS_ROOT_CREATE_DEACTIVATED)) kernfs_activate(kn); |
ba7443bc6 sysfs, kernfs: im... |
934 935 936 937 938 939 940 941 942 943 944 945 |
return root; } /** * kernfs_destroy_root - destroy a kernfs hierarchy * @root: root of the hierarchy to destroy * * Destroy the hierarchy anchored at @root by removing all existing * directories and destroying @root. */ void kernfs_destroy_root(struct kernfs_root *root) { |
324a56e16 kernfs: s/sysfs_d... |
946 |
kernfs_remove(root->kn); /* will also free @root */ |
ba7443bc6 sysfs, kernfs: im... |
947 948 949 |
} /** |
fd7b9f7b9 sysfs, kernfs: mo... |
950 951 952 |
* kernfs_create_dir_ns - create a directory * @parent: parent in which to create a new directory * @name: name of the new directory |
bb8b9d095 kernfs: add @mode... |
953 |
* @mode: mode of the new directory |
488dee96b kernfs: allow cre... |
954 955 |
* @uid: uid of the new directory * @gid: gid of the new directory |
fd7b9f7b9 sysfs, kernfs: mo... |
956 957 958 959 960 |
* @priv: opaque data associated with the new directory * @ns: optional namespace tag of the directory * * Returns the created node on success, ERR_PTR() value on failure. */ |
324a56e16 kernfs: s/sysfs_d... |
961 |
struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
bb8b9d095 kernfs: add @mode... |
962 |
const char *name, umode_t mode, |
488dee96b kernfs: allow cre... |
963 |
kuid_t uid, kgid_t gid, |
bb8b9d095 kernfs: add @mode... |
964 |
void *priv, const void *ns) |
fd7b9f7b9 sysfs, kernfs: mo... |
965 |
{ |
324a56e16 kernfs: s/sysfs_d... |
966 |
struct kernfs_node *kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
967 968 969 |
int rc; /* allocate */ |
488dee96b kernfs: allow cre... |
970 971 |
kn = kernfs_new_node(parent, name, mode | S_IFDIR, uid, gid, KERNFS_DIR); |
324a56e16 kernfs: s/sysfs_d... |
972 |
if (!kn) |
fd7b9f7b9 sysfs, kernfs: mo... |
973 |
return ERR_PTR(-ENOMEM); |
adc5e8b58 kernfs: drop s_ p... |
974 975 |
kn->dir.root = parent->dir.root; kn->ns = ns; |
324a56e16 kernfs: s/sysfs_d... |
976 |
kn->priv = priv; |
fd7b9f7b9 sysfs, kernfs: mo... |
977 978 |
/* link in */ |
988cd7afb kernfs: remove ke... |
979 |
rc = kernfs_add_one(kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
980 |
if (!rc) |
324a56e16 kernfs: s/sysfs_d... |
981 |
return kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
982 |
|
324a56e16 kernfs: s/sysfs_d... |
983 |
kernfs_put(kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
984 985 |
return ERR_PTR(rc); } |
ea015218f kernfs: Add suppo... |
986 987 988 989 990 991 992 993 994 995 996 997 998 999 |
/** * kernfs_create_empty_dir - create an always empty directory * @parent: parent in which to create a new directory * @name: name of the new directory * * Returns the created node on success, ERR_PTR() value on failure. */ struct kernfs_node *kernfs_create_empty_dir(struct kernfs_node *parent, const char *name) { struct kernfs_node *kn; int rc; /* allocate */ |
488dee96b kernfs: allow cre... |
1000 1001 |
kn = kernfs_new_node(parent, name, S_IRUGO|S_IXUGO|S_IFDIR, GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, KERNFS_DIR); |
ea015218f kernfs: Add suppo... |
1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 |
if (!kn) return ERR_PTR(-ENOMEM); kn->flags |= KERNFS_EMPTY_DIR; kn->dir.root = parent->dir.root; kn->ns = NULL; kn->priv = NULL; /* link in */ rc = kernfs_add_one(kn); if (!rc) return kn; kernfs_put(kn); return ERR_PTR(rc); } |
c637b8acb kernfs: s/sysfs/k... |
1018 1019 1020 |
static struct dentry *kernfs_iop_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
fd7b9f7b9 sysfs, kernfs: mo... |
1021 |
{ |
19bbb9262 kernfs: allow neg... |
1022 |
struct dentry *ret; |
319ba91d3 kernfs: don't set... |
1023 |
struct kernfs_node *parent = dir->i_private; |
324a56e16 kernfs: s/sysfs_d... |
1024 |
struct kernfs_node *kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
1025 1026 |
struct inode *inode; const void *ns = NULL; |
a797bfc30 kernfs: s/sysfs/k... |
1027 |
mutex_lock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1028 |
|
324a56e16 kernfs: s/sysfs_d... |
1029 |
if (kernfs_ns_enabled(parent)) |
c525aaddc kernfs: s/sysfs/k... |
1030 |
ns = kernfs_info(dir->i_sb)->ns; |
fd7b9f7b9 sysfs, kernfs: mo... |
1031 |
|
324a56e16 kernfs: s/sysfs_d... |
1032 |
kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b9 sysfs, kernfs: mo... |
1033 1034 |
/* no such entry */ |
b9c9dad0c kernfs: add missi... |
1035 |
if (!kn || !kernfs_active(kn)) { |
19bbb9262 kernfs: allow neg... |
1036 |
ret = NULL; |
fd7b9f7b9 sysfs, kernfs: mo... |
1037 1038 |
goto out_unlock; } |
fd7b9f7b9 sysfs, kernfs: mo... |
1039 1040 |
/* attach dentry and inode */ |
c637b8acb kernfs: s/sysfs/k... |
1041 |
inode = kernfs_get_inode(dir->i_sb, kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
1042 1043 1044 1045 1046 1047 |
if (!inode) { ret = ERR_PTR(-ENOMEM); goto out_unlock; } /* instantiate and hash dentry */ |
41d28bca2 switch d_material... |
1048 |
ret = d_splice_alias(inode, dentry); |
fd7b9f7b9 sysfs, kernfs: mo... |
1049 |
out_unlock: |
a797bfc30 kernfs: s/sysfs/k... |
1050 |
mutex_unlock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1051 1052 |
return ret; } |
80b9bbefc kernfs: add kernf... |
1053 1054 1055 1056 |
static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { struct kernfs_node *parent = dir->i_private; |
90c07c895 kernfs: rename ke... |
1057 |
struct kernfs_syscall_ops *scops = kernfs_root(parent)->syscall_ops; |
07c7530dd kernfs: invoke di... |
1058 |
int ret; |
80b9bbefc kernfs: add kernf... |
1059 |
|
90c07c895 kernfs: rename ke... |
1060 |
if (!scops || !scops->mkdir) |
80b9bbefc kernfs: add kernf... |
1061 |
return -EPERM; |
07c7530dd kernfs: invoke di... |
1062 1063 |
if (!kernfs_get_active(parent)) return -ENODEV; |
90c07c895 kernfs: rename ke... |
1064 |
ret = scops->mkdir(parent, dentry->d_name.name, mode); |
07c7530dd kernfs: invoke di... |
1065 1066 1067 |
kernfs_put_active(parent); return ret; |
80b9bbefc kernfs: add kernf... |
1068 1069 1070 1071 |
} static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry) { |
319ba91d3 kernfs: don't set... |
1072 |
struct kernfs_node *kn = kernfs_dentry_node(dentry); |
90c07c895 kernfs: rename ke... |
1073 |
struct kernfs_syscall_ops *scops = kernfs_root(kn)->syscall_ops; |
07c7530dd kernfs: invoke di... |
1074 |
int ret; |
80b9bbefc kernfs: add kernf... |
1075 |
|
90c07c895 kernfs: rename ke... |
1076 |
if (!scops || !scops->rmdir) |
80b9bbefc kernfs: add kernf... |
1077 |
return -EPERM; |
07c7530dd kernfs: invoke di... |
1078 1079 |
if (!kernfs_get_active(kn)) return -ENODEV; |
90c07c895 kernfs: rename ke... |
1080 |
ret = scops->rmdir(kn); |
07c7530dd kernfs: invoke di... |
1081 1082 1083 |
kernfs_put_active(kn); return ret; |
80b9bbefc kernfs: add kernf... |
1084 1085 1086 |
} static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry, |
1cd66c93b fs: make remainin... |
1087 1088 |
struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) |
80b9bbefc kernfs: add kernf... |
1089 |
{ |
319ba91d3 kernfs: don't set... |
1090 |
struct kernfs_node *kn = kernfs_dentry_node(old_dentry); |
80b9bbefc kernfs: add kernf... |
1091 |
struct kernfs_node *new_parent = new_dir->i_private; |
90c07c895 kernfs: rename ke... |
1092 |
struct kernfs_syscall_ops *scops = kernfs_root(kn)->syscall_ops; |
07c7530dd kernfs: invoke di... |
1093 |
int ret; |
80b9bbefc kernfs: add kernf... |
1094 |
|
1cd66c93b fs: make remainin... |
1095 1096 |
if (flags) return -EINVAL; |
90c07c895 kernfs: rename ke... |
1097 |
if (!scops || !scops->rename) |
80b9bbefc kernfs: add kernf... |
1098 |
return -EPERM; |
07c7530dd kernfs: invoke di... |
1099 1100 1101 1102 1103 1104 1105 |
if (!kernfs_get_active(kn)) return -ENODEV; if (!kernfs_get_active(new_parent)) { kernfs_put_active(kn); return -ENODEV; } |
90c07c895 kernfs: rename ke... |
1106 |
ret = scops->rename(kn, new_parent, new_dentry->d_name.name); |
07c7530dd kernfs: invoke di... |
1107 1108 1109 1110 |
kernfs_put_active(new_parent); kernfs_put_active(kn); return ret; |
80b9bbefc kernfs: add kernf... |
1111 |
} |
a797bfc30 kernfs: s/sysfs/k... |
1112 |
const struct inode_operations kernfs_dir_iops = { |
c637b8acb kernfs: s/sysfs/k... |
1113 1114 1115 1116 |
.lookup = kernfs_iop_lookup, .permission = kernfs_iop_permission, .setattr = kernfs_iop_setattr, .getattr = kernfs_iop_getattr, |
c637b8acb kernfs: s/sysfs/k... |
1117 |
.listxattr = kernfs_iop_listxattr, |
80b9bbefc kernfs: add kernf... |
1118 1119 1120 1121 |
.mkdir = kernfs_iop_mkdir, .rmdir = kernfs_iop_rmdir, .rename = kernfs_iop_rename, |
fd7b9f7b9 sysfs, kernfs: mo... |
1122 |
}; |
c637b8acb kernfs: s/sysfs/k... |
1123 |
static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b9 sysfs, kernfs: mo... |
1124 |
{ |
324a56e16 kernfs: s/sysfs_d... |
1125 |
struct kernfs_node *last; |
fd7b9f7b9 sysfs, kernfs: mo... |
1126 1127 1128 1129 1130 |
while (true) { struct rb_node *rbn; last = pos; |
df23fc39b kernfs: s/sysfs/k... |
1131 |
if (kernfs_type(pos) != KERNFS_DIR) |
fd7b9f7b9 sysfs, kernfs: mo... |
1132 |
break; |
adc5e8b58 kernfs: drop s_ p... |
1133 |
rbn = rb_first(&pos->dir.children); |
fd7b9f7b9 sysfs, kernfs: mo... |
1134 1135 |
if (!rbn) break; |
324a56e16 kernfs: s/sysfs_d... |
1136 |
pos = rb_to_kn(rbn); |
fd7b9f7b9 sysfs, kernfs: mo... |
1137 1138 1139 1140 1141 1142 |
} return last; } /** |
c637b8acb kernfs: s/sysfs/k... |
1143 |
* kernfs_next_descendant_post - find the next descendant for post-order walk |
fd7b9f7b9 sysfs, kernfs: mo... |
1144 |
* @pos: the current position (%NULL to initiate traversal) |
324a56e16 kernfs: s/sysfs_d... |
1145 |
* @root: kernfs_node whose descendants to walk |
fd7b9f7b9 sysfs, kernfs: mo... |
1146 1147 1148 1149 1150 |
* * 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. */ |
c637b8acb kernfs: s/sysfs/k... |
1151 1152 |
static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, struct kernfs_node *root) |
fd7b9f7b9 sysfs, kernfs: mo... |
1153 1154 |
{ struct rb_node *rbn; |
a797bfc30 kernfs: s/sysfs/k... |
1155 |
lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1156 1157 1158 |
/* if first iteration, visit leftmost descendant which may be root */ if (!pos) |
c637b8acb kernfs: s/sysfs/k... |
1159 |
return kernfs_leftmost_descendant(root); |
fd7b9f7b9 sysfs, kernfs: mo... |
1160 1161 1162 1163 1164 1165 |
/* if we visited @root, we're done */ if (pos == root) return NULL; /* if there's an unvisited sibling, visit its leftmost descendant */ |
adc5e8b58 kernfs: drop s_ p... |
1166 |
rbn = rb_next(&pos->rb); |
fd7b9f7b9 sysfs, kernfs: mo... |
1167 |
if (rbn) |
c637b8acb kernfs: s/sysfs/k... |
1168 |
return kernfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b9 sysfs, kernfs: mo... |
1169 1170 |
/* no sibling left, visit parent */ |
adc5e8b58 kernfs: drop s_ p... |
1171 |
return pos->parent; |
fd7b9f7b9 sysfs, kernfs: mo... |
1172 |
} |
d35258ef7 kernfs: allow nod... |
1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 |
/** * kernfs_activate - activate a node which started deactivated * @kn: kernfs_node whose subtree is to be activated * * If the root has KERNFS_ROOT_CREATE_DEACTIVATED set, a newly created node * needs to be explicitly activated. A node which hasn't been activated * isn't visible to userland and deactivation is skipped during its * removal. This is useful to construct atomic init sequences where * creation of multiple nodes should either succeed or fail atomically. * * The caller is responsible for ensuring that this function is not called * after kernfs_remove*() is invoked on @kn. */ void kernfs_activate(struct kernfs_node *kn) { struct kernfs_node *pos; mutex_lock(&kernfs_mutex); pos = NULL; while ((pos = kernfs_next_descendant_post(pos, kn))) { if (!pos || (pos->flags & KERNFS_ACTIVATED)) continue; WARN_ON_ONCE(pos->parent && RB_EMPTY_NODE(&pos->rb)); WARN_ON_ONCE(atomic_read(&pos->active) != KN_DEACTIVATED_BIAS); atomic_sub(KN_DEACTIVATED_BIAS, &pos->active); pos->flags |= KERNFS_ACTIVATED; } mutex_unlock(&kernfs_mutex); } |
988cd7afb kernfs: remove ke... |
1206 |
static void __kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b9 sysfs, kernfs: mo... |
1207 |
{ |
35beab063 kernfs: restructu... |
1208 1209 1210 |
struct kernfs_node *pos; lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1211 |
|
6b0afc2a2 kernfs, sysfs, dr... |
1212 1213 1214 1215 1216 1217 |
/* * Short-circuit if non-root @kn has already finished removal. * This is for kernfs_remove_self() which plays with active ref * after removal. */ if (!kn || (kn->parent && RB_EMPTY_NODE(&kn->rb))) |
ce9b499c9 Revert "kernfs: r... |
1218 |
return; |
c637b8acb kernfs: s/sysfs/k... |
1219 1220 |
pr_debug("kernfs %s: removing ", kn->name); |
fd7b9f7b9 sysfs, kernfs: mo... |
1221 |
|
81c173cb5 kernfs: remove KE... |
1222 |
/* prevent any new usage under @kn by deactivating all nodes */ |
35beab063 kernfs: restructu... |
1223 1224 |
pos = NULL; while ((pos = kernfs_next_descendant_post(pos, kn))) |
81c173cb5 kernfs: remove KE... |
1225 1226 |
if (kernfs_active(pos)) atomic_add(KN_DEACTIVATED_BIAS, &pos->active); |
35beab063 kernfs: restructu... |
1227 1228 |
/* deactivate and unlink the subtree node-by-node */ |
fd7b9f7b9 sysfs, kernfs: mo... |
1229 |
do { |
35beab063 kernfs: restructu... |
1230 1231 1232 |
pos = kernfs_leftmost_descendant(kn); /* |
81c173cb5 kernfs: remove KE... |
1233 1234 1235 1236 |
* kernfs_drain() drops kernfs_mutex temporarily and @pos's * base ref could have been put by someone else by the time * the function returns. Make sure it doesn't go away * underneath us. |
35beab063 kernfs: restructu... |
1237 1238 |
*/ kernfs_get(pos); |
d35258ef7 kernfs: allow nod... |
1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 |
/* * Drain iff @kn was activated. This avoids draining and * its lockdep annotations for nodes which have never been * activated and allows embedding kernfs_remove() in create * error paths without worrying about draining. */ if (kn->flags & KERNFS_ACTIVATED) kernfs_drain(pos); else WARN_ON_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS); |
35beab063 kernfs: restructu... |
1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 |
/* * kernfs_unlink_sibling() succeeds once per node. Use it * to decide who's responsible for cleanups. */ if (!pos->parent || kernfs_unlink_sibling(pos)) { struct kernfs_iattrs *ps_iattr = pos->parent ? pos->parent->iattr : NULL; /* update timestamps on the parent */ if (ps_iattr) { |
058952196 kernfs: clean up ... |
1260 1261 |
ktime_get_real_ts64(&ps_iattr->ia_ctime); ps_iattr->ia_mtime = ps_iattr->ia_ctime; |
35beab063 kernfs: restructu... |
1262 |
} |
988cd7afb kernfs: remove ke... |
1263 |
kernfs_put(pos); |
35beab063 kernfs: restructu... |
1264 1265 1266 1267 |
} kernfs_put(pos); } while (pos != kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
1268 1269 1270 |
} /** |
324a56e16 kernfs: s/sysfs_d... |
1271 1272 |
* kernfs_remove - remove a kernfs_node recursively * @kn: the kernfs_node to remove |
fd7b9f7b9 sysfs, kernfs: mo... |
1273 |
* |
324a56e16 kernfs: s/sysfs_d... |
1274 |
* Remove @kn along with all its subdirectories and files. |
fd7b9f7b9 sysfs, kernfs: mo... |
1275 |
*/ |
324a56e16 kernfs: s/sysfs_d... |
1276 |
void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b9 sysfs, kernfs: mo... |
1277 |
{ |
988cd7afb kernfs: remove ke... |
1278 1279 1280 |
mutex_lock(&kernfs_mutex); __kernfs_remove(kn); mutex_unlock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1281 1282 1283 |
} /** |
6b0afc2a2 kernfs, sysfs, dr... |
1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 |
* kernfs_break_active_protection - break out of active protection * @kn: the self kernfs_node * * The caller must be running off of a kernfs operation which is invoked * with an active reference - e.g. one of kernfs_ops. Each invocation of * this function must also be matched with an invocation of * kernfs_unbreak_active_protection(). * * This function releases the active reference of @kn the caller is * holding. Once this function is called, @kn may be removed at any point * and the caller is solely responsible for ensuring that the objects it * dereferences are accessible. */ void kernfs_break_active_protection(struct kernfs_node *kn) { /* * Take out ourself out of the active ref dependency chain. If * we're called without an active ref, lockdep will complain. */ kernfs_put_active(kn); } /** * kernfs_unbreak_active_protection - undo kernfs_break_active_protection() * @kn: the self kernfs_node * * If kernfs_break_active_protection() was called, this function must be * invoked before finishing the kernfs operation. Note that while this * function restores the active reference, it doesn't and can't actually * restore the active protection - @kn may already or be in the process of * being removed. Once kernfs_break_active_protection() is invoked, that * protection is irreversibly gone for the kernfs operation instance. * * While this function may be called at any point after * kernfs_break_active_protection() is invoked, its most useful location * would be right before the enclosing kernfs operation returns. */ void kernfs_unbreak_active_protection(struct kernfs_node *kn) { /* * @kn->active could be in any state; however, the increment we do * here will be undone as soon as the enclosing kernfs operation * finishes and this temporary bump can't break anything. If @kn * is alive, nothing changes. If @kn is being deactivated, the * soon-to-follow put will either finish deactivation or restore * deactivated state. If @kn is already removed, the temporary * bump is guaranteed to be gone before @kn is released. */ atomic_inc(&kn->active); if (kernfs_lockdep(kn)) rwsem_acquire(&kn->dep_map, 0, 1, _RET_IP_); } /** * kernfs_remove_self - remove a kernfs_node from its own method * @kn: the self kernfs_node to remove * * The caller must be running off of a kernfs operation which is invoked * with an active reference - e.g. one of kernfs_ops. This can be used to * implement a file operation which deletes itself. * * For example, the "delete" file for a sysfs device directory can be * implemented by invoking kernfs_remove_self() on the "delete" file * itself. This function breaks the circular dependency of trying to * deactivate self while holding an active ref itself. It isn't necessary * to modify the usual removal path to use kernfs_remove_self(). The * "delete" implementation can simply invoke kernfs_remove_self() on self * before proceeding with the usual removal path. kernfs will ignore later * kernfs_remove() on self. * * kernfs_remove_self() can be called multiple times concurrently on the * same kernfs_node. Only the first one actually performs removal and * returns %true. All others will wait until the kernfs operation which * won self-removal finishes and return %false. Note that the losers wait * for the completion of not only the winning kernfs_remove_self() but also * the whole kernfs_ops which won the arbitration. This can be used to * guarantee, for example, all concurrent writes to a "delete" file to * finish only after the whole operation is complete. */ bool kernfs_remove_self(struct kernfs_node *kn) { bool ret; mutex_lock(&kernfs_mutex); kernfs_break_active_protection(kn); /* * SUICIDAL is used to arbitrate among competing invocations. Only * the first one will actually perform removal. When the removal * is complete, SUICIDED is set and the active ref is restored * while holding kernfs_mutex. The ones which lost arbitration * waits for SUICDED && drained which can happen only after the * enclosing kernfs operation which executed the winning instance * of kernfs_remove_self() finished. */ if (!(kn->flags & KERNFS_SUICIDAL)) { kn->flags |= KERNFS_SUICIDAL; __kernfs_remove(kn); kn->flags |= KERNFS_SUICIDED; ret = true; } else { wait_queue_head_t *waitq = &kernfs_root(kn)->deactivate_waitq; DEFINE_WAIT(wait); while (true) { prepare_to_wait(waitq, &wait, TASK_UNINTERRUPTIBLE); if ((kn->flags & KERNFS_SUICIDED) && atomic_read(&kn->active) == KN_DEACTIVATED_BIAS) break; mutex_unlock(&kernfs_mutex); schedule(); mutex_lock(&kernfs_mutex); } finish_wait(waitq, &wait); WARN_ON_ONCE(!RB_EMPTY_NODE(&kn->rb)); ret = false; } /* * This must be done while holding kernfs_mutex; otherwise, waiting * for SUICIDED && deactivated could finish prematurely. */ kernfs_unbreak_active_protection(kn); mutex_unlock(&kernfs_mutex); return ret; } /** |
324a56e16 kernfs: s/sysfs_d... |
1415 1416 1417 1418 |
* kernfs_remove_by_name_ns - find a kernfs_node by name and remove it * @parent: parent of the target * @name: name of the kernfs_node to remove * @ns: namespace tag of the kernfs_node to remove |
fd7b9f7b9 sysfs, kernfs: mo... |
1419 |
* |
324a56e16 kernfs: s/sysfs_d... |
1420 1421 |
* Look for the kernfs_node with @name and @ns under @parent and remove it. * Returns 0 on success, -ENOENT if such entry doesn't exist. |
fd7b9f7b9 sysfs, kernfs: mo... |
1422 |
*/ |
324a56e16 kernfs: s/sysfs_d... |
1423 |
int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b9 sysfs, kernfs: mo... |
1424 1425 |
const void *ns) { |
324a56e16 kernfs: s/sysfs_d... |
1426 |
struct kernfs_node *kn; |
fd7b9f7b9 sysfs, kernfs: mo... |
1427 |
|
324a56e16 kernfs: s/sysfs_d... |
1428 |
if (!parent) { |
c637b8acb kernfs: s/sysfs/k... |
1429 1430 |
WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory ", |
fd7b9f7b9 sysfs, kernfs: mo... |
1431 1432 1433 |
name); return -ENOENT; } |
988cd7afb kernfs: remove ke... |
1434 |
mutex_lock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1435 |
|
324a56e16 kernfs: s/sysfs_d... |
1436 1437 |
kn = kernfs_find_ns(parent, name, ns); if (kn) |
988cd7afb kernfs: remove ke... |
1438 |
__kernfs_remove(kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
1439 |
|
988cd7afb kernfs: remove ke... |
1440 |
mutex_unlock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1441 |
|
324a56e16 kernfs: s/sysfs_d... |
1442 |
if (kn) |
fd7b9f7b9 sysfs, kernfs: mo... |
1443 1444 1445 1446 1447 1448 1449 |
return 0; else return -ENOENT; } /** * kernfs_rename_ns - move and rename a kernfs_node |
324a56e16 kernfs: s/sysfs_d... |
1450 |
* @kn: target node |
fd7b9f7b9 sysfs, kernfs: mo... |
1451 1452 1453 1454 |
* @new_parent: new parent to put @sd under * @new_name: new name * @new_ns: new namespace tag */ |
324a56e16 kernfs: s/sysfs_d... |
1455 |
int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b9 sysfs, kernfs: mo... |
1456 1457 |
const char *new_name, const void *new_ns) { |
3eef34ad7 kernfs: implement... |
1458 1459 |
struct kernfs_node *old_parent; const char *old_name = NULL; |
fd7b9f7b9 sysfs, kernfs: mo... |
1460 |
int error; |
3eef34ad7 kernfs: implement... |
1461 1462 1463 |
/* can't move or rename root */ if (!kn->parent) return -EINVAL; |
798c75a0d Revert "kernfs: r... |
1464 |
mutex_lock(&kernfs_mutex); |
d0ae3d434 kernfs: add REMOV... |
1465 |
error = -ENOENT; |
ea015218f kernfs: Add suppo... |
1466 1467 |
if (!kernfs_active(kn) || !kernfs_active(new_parent) || (new_parent->flags & KERNFS_EMPTY_DIR)) |
d0ae3d434 kernfs: add REMOV... |
1468 |
goto out; |
fd7b9f7b9 sysfs, kernfs: mo... |
1469 |
error = 0; |
adc5e8b58 kernfs: drop s_ p... |
1470 1471 |
if ((kn->parent == new_parent) && (kn->ns == new_ns) && (strcmp(kn->name, new_name) == 0)) |
798c75a0d Revert "kernfs: r... |
1472 |
goto out; /* nothing to rename */ |
fd7b9f7b9 sysfs, kernfs: mo... |
1473 1474 1475 |
error = -EEXIST; if (kernfs_find_ns(new_parent, new_name, new_ns)) |
798c75a0d Revert "kernfs: r... |
1476 |
goto out; |
fd7b9f7b9 sysfs, kernfs: mo... |
1477 |
|
324a56e16 kernfs: s/sysfs_d... |
1478 |
/* rename kernfs_node */ |
adc5e8b58 kernfs: drop s_ p... |
1479 |
if (strcmp(kn->name, new_name) != 0) { |
fd7b9f7b9 sysfs, kernfs: mo... |
1480 |
error = -ENOMEM; |
75287a677 kernfs: convert n... |
1481 |
new_name = kstrdup_const(new_name, GFP_KERNEL); |
fd7b9f7b9 sysfs, kernfs: mo... |
1482 |
if (!new_name) |
798c75a0d Revert "kernfs: r... |
1483 |
goto out; |
3eef34ad7 kernfs: implement... |
1484 1485 |
} else { new_name = NULL; |
fd7b9f7b9 sysfs, kernfs: mo... |
1486 1487 1488 1489 1490 |
} /* * Move to the appropriate place in the appropriate directories rbtree. */ |
c637b8acb kernfs: s/sysfs/k... |
1491 |
kernfs_unlink_sibling(kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
1492 |
kernfs_get(new_parent); |
3eef34ad7 kernfs: implement... |
1493 1494 1495 1496 1497 |
/* rename_lock protects ->parent and ->name accessors */ spin_lock_irq(&kernfs_rename_lock); old_parent = kn->parent; |
adc5e8b58 kernfs: drop s_ p... |
1498 |
kn->parent = new_parent; |
3eef34ad7 kernfs: implement... |
1499 1500 1501 |
kn->ns = new_ns; if (new_name) { |
dfeb0750b kernfs: remove KE... |
1502 |
old_name = kn->name; |
3eef34ad7 kernfs: implement... |
1503 1504 1505 1506 |
kn->name = new_name; } spin_unlock_irq(&kernfs_rename_lock); |
9561a8961 kernfs: fix hash ... |
1507 |
kn->hash = kernfs_name_hash(kn->name, kn->ns); |
c637b8acb kernfs: s/sysfs/k... |
1508 |
kernfs_link_sibling(kn); |
fd7b9f7b9 sysfs, kernfs: mo... |
1509 |
|
3eef34ad7 kernfs: implement... |
1510 |
kernfs_put(old_parent); |
75287a677 kernfs: convert n... |
1511 |
kfree_const(old_name); |
3eef34ad7 kernfs: implement... |
1512 |
|
fd7b9f7b9 sysfs, kernfs: mo... |
1513 |
error = 0; |
798c75a0d Revert "kernfs: r... |
1514 |
out: |
a797bfc30 kernfs: s/sysfs/k... |
1515 |
mutex_unlock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1516 1517 |
return error; } |
fd7b9f7b9 sysfs, kernfs: mo... |
1518 |
/* Relationship between s_mode and the DT_xxx types */ |
324a56e16 kernfs: s/sysfs_d... |
1519 |
static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b9 sysfs, kernfs: mo... |
1520 |
{ |
adc5e8b58 kernfs: drop s_ p... |
1521 |
return (kn->mode >> 12) & 15; |
fd7b9f7b9 sysfs, kernfs: mo... |
1522 |
} |
c637b8acb kernfs: s/sysfs/k... |
1523 |
static int kernfs_dir_fop_release(struct inode *inode, struct file *filp) |
fd7b9f7b9 sysfs, kernfs: mo... |
1524 1525 1526 1527 |
{ kernfs_put(filp->private_data); return 0; } |
c637b8acb kernfs: s/sysfs/k... |
1528 |
static struct kernfs_node *kernfs_dir_pos(const void *ns, |
324a56e16 kernfs: s/sysfs_d... |
1529 |
struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) |
fd7b9f7b9 sysfs, kernfs: mo... |
1530 1531 |
{ if (pos) { |
81c173cb5 kernfs: remove KE... |
1532 |
int valid = kernfs_active(pos) && |
798c75a0d Revert "kernfs: r... |
1533 |
pos->parent == parent && hash == pos->hash; |
fd7b9f7b9 sysfs, kernfs: mo... |
1534 1535 1536 1537 1538 |
kernfs_put(pos); if (!valid) pos = NULL; } if (!pos && (hash > 1) && (hash < INT_MAX)) { |
adc5e8b58 kernfs: drop s_ p... |
1539 |
struct rb_node *node = parent->dir.children.rb_node; |
fd7b9f7b9 sysfs, kernfs: mo... |
1540 |
while (node) { |
324a56e16 kernfs: s/sysfs_d... |
1541 |
pos = rb_to_kn(node); |
fd7b9f7b9 sysfs, kernfs: mo... |
1542 |
|
adc5e8b58 kernfs: drop s_ p... |
1543 |
if (hash < pos->hash) |
fd7b9f7b9 sysfs, kernfs: mo... |
1544 |
node = node->rb_left; |
adc5e8b58 kernfs: drop s_ p... |
1545 |
else if (hash > pos->hash) |
fd7b9f7b9 sysfs, kernfs: mo... |
1546 1547 1548 1549 1550 |
node = node->rb_right; else break; } } |
b9c9dad0c kernfs: add missi... |
1551 1552 |
/* Skip over entries which are dying/dead or in the wrong namespace */ while (pos && (!kernfs_active(pos) || pos->ns != ns)) { |
adc5e8b58 kernfs: drop s_ p... |
1553 |
struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b9 sysfs, kernfs: mo... |
1554 1555 1556 |
if (!node) pos = NULL; else |
324a56e16 kernfs: s/sysfs_d... |
1557 |
pos = rb_to_kn(node); |
fd7b9f7b9 sysfs, kernfs: mo... |
1558 1559 1560 |
} return pos; } |
c637b8acb kernfs: s/sysfs/k... |
1561 |
static struct kernfs_node *kernfs_dir_next_pos(const void *ns, |
324a56e16 kernfs: s/sysfs_d... |
1562 |
struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) |
fd7b9f7b9 sysfs, kernfs: mo... |
1563 |
{ |
c637b8acb kernfs: s/sysfs/k... |
1564 |
pos = kernfs_dir_pos(ns, parent, ino, pos); |
b9c9dad0c kernfs: add missi... |
1565 |
if (pos) { |
fd7b9f7b9 sysfs, kernfs: mo... |
1566 |
do { |
adc5e8b58 kernfs: drop s_ p... |
1567 |
struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b9 sysfs, kernfs: mo... |
1568 1569 1570 |
if (!node) pos = NULL; else |
324a56e16 kernfs: s/sysfs_d... |
1571 |
pos = rb_to_kn(node); |
b9c9dad0c kernfs: add missi... |
1572 1573 |
} while (pos && (!kernfs_active(pos) || pos->ns != ns)); } |
fd7b9f7b9 sysfs, kernfs: mo... |
1574 1575 |
return pos; } |
c637b8acb kernfs: s/sysfs/k... |
1576 |
static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) |
fd7b9f7b9 sysfs, kernfs: mo... |
1577 1578 |
{ struct dentry *dentry = file->f_path.dentry; |
319ba91d3 kernfs: don't set... |
1579 |
struct kernfs_node *parent = kernfs_dentry_node(dentry); |
324a56e16 kernfs: s/sysfs_d... |
1580 |
struct kernfs_node *pos = file->private_data; |
fd7b9f7b9 sysfs, kernfs: mo... |
1581 1582 1583 1584 |
const void *ns = NULL; if (!dir_emit_dots(file, ctx)) return 0; |
a797bfc30 kernfs: s/sysfs/k... |
1585 |
mutex_lock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1586 |
|
324a56e16 kernfs: s/sysfs_d... |
1587 |
if (kernfs_ns_enabled(parent)) |
c525aaddc kernfs: s/sysfs/k... |
1588 |
ns = kernfs_info(dentry->d_sb)->ns; |
fd7b9f7b9 sysfs, kernfs: mo... |
1589 |
|
c637b8acb kernfs: s/sysfs/k... |
1590 |
for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b9 sysfs, kernfs: mo... |
1591 |
pos; |
c637b8acb kernfs: s/sysfs/k... |
1592 |
pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
adc5e8b58 kernfs: drop s_ p... |
1593 |
const char *name = pos->name; |
fd7b9f7b9 sysfs, kernfs: mo... |
1594 1595 |
unsigned int type = dt_type(pos); int len = strlen(name); |
c53cd490b kernfs: introduce... |
1596 |
ino_t ino = pos->id.ino; |
fd7b9f7b9 sysfs, kernfs: mo... |
1597 |
|
adc5e8b58 kernfs: drop s_ p... |
1598 |
ctx->pos = pos->hash; |
fd7b9f7b9 sysfs, kernfs: mo... |
1599 1600 |
file->private_data = pos; kernfs_get(pos); |
a797bfc30 kernfs: s/sysfs/k... |
1601 |
mutex_unlock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1602 1603 |
if (!dir_emit(ctx, name, len, ino, type)) return 0; |
a797bfc30 kernfs: s/sysfs/k... |
1604 |
mutex_lock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1605 |
} |
a797bfc30 kernfs: s/sysfs/k... |
1606 |
mutex_unlock(&kernfs_mutex); |
fd7b9f7b9 sysfs, kernfs: mo... |
1607 1608 1609 1610 |
file->private_data = NULL; ctx->pos = INT_MAX; return 0; } |
a797bfc30 kernfs: s/sysfs/k... |
1611 |
const struct file_operations kernfs_dir_fops = { |
fd7b9f7b9 sysfs, kernfs: mo... |
1612 |
.read = generic_read_dir, |
8cb0d2c1c kernfs: no point ... |
1613 |
.iterate_shared = kernfs_fop_readdir, |
c637b8acb kernfs: s/sysfs/k... |
1614 |
.release = kernfs_dir_fop_release, |
8cb0d2c1c kernfs: no point ... |
1615 |
.llseek = generic_file_llseek, |
fd7b9f7b9 sysfs, kernfs: mo... |
1616 |
}; |