diff options
Diffstat (limited to 'fs/kernfs/dir.c')
| -rw-r--r-- | fs/kernfs/dir.c | 106 |
1 files changed, 67 insertions, 39 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index f33b3baad07c..935ef8cb02b2 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -125,9 +125,9 @@ static struct kernfs_node *kernfs_common_ancestor(struct kernfs_node *a, * kn_to: /n1/n2/n3 [depth=3] * result: /../.. * - * [3] when @kn_to is NULL result will be "(null)" + * [3] when @kn_to is %NULL result will be "(null)" * - * Returns the length of the full path. If the full length is equal to or + * Return: 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. */ @@ -185,10 +185,12 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, * @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. + * similar to strlcpy(). * - * Fills buffer with "(null)" if @kn is NULL. + * Fills buffer with "(null)" if @kn is %NULL. + * + * Return: the length of @kn's name and if @buf isn't long enough, + * it's filled up to @buflen-1 and nul terminated. * * This function can be called from any context. */ @@ -215,7 +217,7 @@ int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen) * path (which includes '..'s) as needed to reach from @from to @to is * returned. * - * Returns the length of the full path. If the full length is equal to or + * Return: 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. */ @@ -287,6 +289,8 @@ out: * * Determines @kn's parent, pins and returns it. This function can be * called from any context. + * + * Return: parent node of @kn */ struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn) { @@ -302,11 +306,11 @@ struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn) } /** - * kernfs_name_hash + * kernfs_name_hash - calculate hash of @ns + @name * @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 ) + * Return: 31-bit hash of ns + name (so it fits in an off_t) */ static unsigned int kernfs_name_hash(const char *name, const void *ns) { @@ -354,8 +358,8 @@ static int kernfs_sd_compare(const struct kernfs_node *left, * Locking: * kernfs_rwsem held exclusive * - * RETURNS: - * 0 on susccess -EEXIST on failure. + * Return: + * %0 on success, -EEXIST on failure. */ static int kernfs_link_sibling(struct kernfs_node *kn) { @@ -394,8 +398,10 @@ static int kernfs_link_sibling(struct kernfs_node *kn) * @kn: kernfs_node of interest * * 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. + * kn->parent->dir.children. + * + * Return: %true if @kn was actually removed, + * %false if @kn wasn't on the rbtree. * * Locking: * kernfs_rwsem held exclusive @@ -419,10 +425,10 @@ static bool kernfs_unlink_sibling(struct kernfs_node *kn) * @kn: kernfs_node to get an active reference to * * Get an active reference of @kn. This function is noop if @kn - * is NULL. + * is %NULL. * - * RETURNS: - * Pointer to @kn on success, NULL on failure. + * Return: + * Pointer to @kn on success, %NULL on failure. */ struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) { @@ -442,7 +448,7 @@ struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) * @kn: kernfs_node to put an active reference to * * Put an active reference to @kn. This function is noop if @kn - * is NULL. + * is %NULL. */ void kernfs_put_active(struct kernfs_node *kn) { @@ -464,7 +470,7 @@ void kernfs_put_active(struct kernfs_node *kn) * kernfs_drain - drain kernfs_node * @kn: kernfs_node to drain * - * Drain existing usages and nuke all existing mmaps of @kn. Mutiple + * Drain existing usages and nuke all existing mmaps of @kn. Multiple * removers may invoke this function concurrently on @kn and all will * return after draining is complete. */ @@ -577,7 +583,7 @@ EXPORT_SYMBOL_GPL(kernfs_put); * 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 + * 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 @@ -684,8 +690,8 @@ struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, * @id's lower 32bits encode ino and upper gen. If the gen portion is * zero, all generations are matched. * - * RETURNS: - * NULL on failure. Return a kernfs node with reference counter incremented + * Return: %NULL on failure, + * otherwise a kernfs node with reference counter incremented. */ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, u64 id) @@ -733,8 +739,8 @@ err_unlock: * function increments nlink of the parent's inode if @kn is a * directory and link into the children list of the parent. * - * RETURNS: - * 0 on success, -EEXIST if entry with the given name already + * Return: + * %0 on success, -EEXIST if entry with the given name already * exists. */ int kernfs_add_one(struct kernfs_node *kn) @@ -797,8 +803,9 @@ out_unlock: * @name: name to look for * @ns: the namespace tag to use * - * Look for kernfs_node with name @name under @parent. Returns pointer to - * the found kernfs_node on success, %NULL on failure. + * Look for kernfs_node with name @name under @parent. + * + * Return: pointer to the found kernfs_node on success, %NULL on failure. */ static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, const unsigned char *name, @@ -871,8 +878,9 @@ static struct kernfs_node *kernfs_walk_ns(struct kernfs_node *parent, * @ns: the namespace tag to use * * Look for kernfs_node with name @name 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. + * if found. This function may sleep. + * + * Return: pointer to the found kernfs_node on success, %NULL on failure. */ struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, const char *name, const void *ns) @@ -896,8 +904,9 @@ EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); * @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. + * if found. This function may sleep. + * + * Return: 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) @@ -919,7 +928,7 @@ struct kernfs_node *kernfs_walk_and_get_ns(struct kernfs_node *parent, * @flags: KERNFS_ROOT_* flags * @priv: opaque data associated with the new directory * - * Returns the root of the new hierarchy on success, ERR_PTR() value on + * Return: the root of the new hierarchy on success, ERR_PTR() value on * failure. */ struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops, @@ -991,6 +1000,8 @@ void kernfs_destroy_root(struct kernfs_root *root) /** * kernfs_root_to_node - return the kernfs_node associated with a kernfs_root * @root: root to use to lookup + * + * Return: @root's kernfs_node */ struct kernfs_node *kernfs_root_to_node(struct kernfs_root *root) { @@ -1007,7 +1018,7 @@ struct kernfs_node *kernfs_root_to_node(struct kernfs_root *root) * @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. + * Return: the created node on success, ERR_PTR() value on failure. */ struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, const char *name, umode_t mode, @@ -1041,7 +1052,7 @@ struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, * @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. + * Return: the created node on success, ERR_PTR() value on failure. */ struct kernfs_node *kernfs_create_empty_dir(struct kernfs_node *parent, const char *name) @@ -1083,20 +1094,30 @@ static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags) /* If the kernfs parent node has changed discard and * proceed to ->lookup. + * + * There's nothing special needed here when getting the + * dentry parent, even if a concurrent rename is in + * progress. That's because the dentry is negative so + * it can only be the target of the rename and it will + * be doing a d_move() not a replace. Consequently the + * dentry d_parent won't change over the d_move(). + * + * Also kernfs negative dentries transitioning from + * negative to positive during revalidate won't happen + * because they are invalidated on containing directory + * changes and the lookup re-done so that a new positive + * dentry can be properly created. */ - spin_lock(&dentry->d_lock); + root = kernfs_root_from_sb(dentry->d_sb); + down_read(&root->kernfs_rwsem); parent = kernfs_dentry_node(dentry->d_parent); if (parent) { - spin_unlock(&dentry->d_lock); - root = kernfs_root(parent); - down_read(&root->kernfs_rwsem); if (kernfs_dir_changed(parent, dentry)) { up_read(&root->kernfs_rwsem); return 0; } - up_read(&root->kernfs_rwsem); - } else - spin_unlock(&dentry->d_lock); + } + up_read(&root->kernfs_rwsem); /* The kernfs parent node hasn't changed, leave the * dentry negative and return success. @@ -1290,6 +1311,8 @@ static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) * 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. + * + * Return: the next descendant to visit or %NULL when done. */ static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, struct kernfs_node *root) @@ -1553,6 +1576,8 @@ void kernfs_unbreak_active_protection(struct kernfs_node *kn) * 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. + * + * Return: %true if @kn is removed by this call, otherwise %false. */ bool kernfs_remove_self(struct kernfs_node *kn) { @@ -1613,7 +1638,8 @@ bool kernfs_remove_self(struct kernfs_node *kn) * @ns: namespace tag of the kernfs_node to remove * * 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. + * + * Return: %0 on success, -ENOENT if such entry doesn't exist. */ int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, const void *ns) @@ -1651,6 +1677,8 @@ int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, * @new_parent: new parent to put @sd under * @new_name: new name * @new_ns: new namespace tag + * + * Return: %0 on success, -errno on failure. */ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, const char *new_name, const void *new_ns) |