diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/klist.c | 206 |
1 files changed, 85 insertions, 121 deletions
diff --git a/lib/klist.c b/lib/klist.c index ebba9488046..cca37f96faa 100644 --- a/lib/klist.c +++ b/lib/klist.c @@ -1,38 +1,37 @@ /* - * klist.c - Routines for manipulating klists. + * klist.c - Routines for manipulating klists. * + * Copyright (C) 2005 Patrick Mochel * - * This klist interface provides a couple of structures that wrap around - * struct list_head to provide explicit list "head" (struct klist) and - * list "node" (struct klist_node) objects. For struct klist, a spinlock - * is included that protects access to the actual list itself. struct - * klist_node provides a pointer to the klist that owns it and a kref - * reference count that indicates the number of current users of that node - * in the list. + * This file is released under the GPL v2. * - * The entire point is to provide an interface for iterating over a list - * that is safe and allows for modification of the list during the - * iteration (e.g. insertion and removal), including modification of the - * current node on the list. + * This klist interface provides a couple of structures that wrap around + * struct list_head to provide explicit list "head" (struct klist) and list + * "node" (struct klist_node) objects. For struct klist, a spinlock is + * included that protects access to the actual list itself. struct + * klist_node provides a pointer to the klist that owns it and a kref + * reference count that indicates the number of current users of that node + * in the list. * - * It works using a 3rd object type - struct klist_iter - that is declared - * and initialized before an iteration. klist_next() is used to acquire the - * next element in the list. It returns NULL if there are no more items. - * Internally, that routine takes the klist's lock, decrements the reference - * count of the previous klist_node and increments the count of the next - * klist_node. It then drops the lock and returns. + * The entire point is to provide an interface for iterating over a list + * that is safe and allows for modification of the list during the + * iteration (e.g. insertion and removal), including modification of the + * current node on the list. * - * There are primitives for adding and removing nodes to/from a klist. - * When deleting, klist_del() will simply decrement the reference count. - * Only when the count goes to 0 is the node removed from the list. - * klist_remove() will try to delete the node from the list and block - * until it is actually removed. This is useful for objects (like devices) - * that have been removed from the system and must be freed (but must wait - * until all accessors have finished). + * It works using a 3rd object type - struct klist_iter - that is declared + * and initialized before an iteration. klist_next() is used to acquire the + * next element in the list. It returns NULL if there are no more items. + * Internally, that routine takes the klist's lock, decrements the + * reference count of the previous klist_node and increments the count of + * the next klist_node. It then drops the lock and returns. * - * Copyright (C) 2005 Patrick Mochel - * - * This file is released under the GPL v2. + * There are primitives for adding and removing nodes to/from a klist. + * When deleting, klist_del() will simply decrement the reference count. + * Only when the count goes to 0 is the node removed from the list. + * klist_remove() will try to delete the node from the list and block until + * it is actually removed. This is useful for objects (like devices) that + * have been removed from the system and must be freed (but must wait until + * all accessors have finished). */ #include <linux/klist.h> @@ -40,10 +39,10 @@ /** - * klist_init - Initialize a klist structure. - * @k: The klist we're initializing. - * @get: The get function for the embedding object (NULL if none) - * @put: The put function for the embedding object (NULL if none) + * klist_init - Initialize a klist structure. + * @k: The klist we're initializing. + * @get: The get function for the embedding object (NULL if none) + * @put: The put function for the embedding object (NULL if none) * * Initialises the klist structure. If the klist_node structures are * going to be embedded in refcounted objects (necessary for safe @@ -51,8 +50,7 @@ * functions that take and release references on the embedding * objects. */ - -void klist_init(struct klist * k, void (*get)(struct klist_node *), +void klist_init(struct klist *k, void (*get)(struct klist_node *), void (*put)(struct klist_node *)) { INIT_LIST_HEAD(&k->k_list); @@ -60,26 +58,23 @@ void klist_init(struct klist * k, void (*get)(struct klist_node *), k->get = get; k->put = put; } - EXPORT_SYMBOL_GPL(klist_init); - -static void add_head(struct klist * k, struct klist_node * n) +static void add_head(struct klist *k, struct klist_node *n) { spin_lock(&k->k_lock); list_add(&n->n_node, &k->k_list); spin_unlock(&k->k_lock); } -static void add_tail(struct klist * k, struct klist_node * n) +static void add_tail(struct klist *k, struct klist_node *n) { spin_lock(&k->k_lock); list_add_tail(&n->n_node, &k->k_list); spin_unlock(&k->k_lock); } - -static void klist_node_init(struct klist * k, struct klist_node * n) +static void klist_node_init(struct klist *k, struct klist_node *n) { INIT_LIST_HEAD(&n->n_node); init_completion(&n->n_removed); @@ -89,37 +84,30 @@ static void klist_node_init(struct klist * k, struct klist_node * n) k->get(n); } - /** - * klist_add_head - Initialize a klist_node and add it to front. - * @n: node we're adding. - * @k: klist it's going on. + * klist_add_head - Initialize a klist_node and add it to front. + * @n: node we're adding. + * @k: klist it's going on. */ - -void klist_add_head(struct klist_node * n, struct klist * k) +void klist_add_head(struct klist_node *n, struct klist *k) { klist_node_init(k, n); add_head(k, n); } - EXPORT_SYMBOL_GPL(klist_add_head); - /** - * klist_add_tail - Initialize a klist_node and add it to back. - * @n: node we're adding. - * @k: klist it's going on. + * klist_add_tail - Initialize a klist_node and add it to back. + * @n: node we're adding. + * @k: klist it's going on. */ - -void klist_add_tail(struct klist_node * n, struct klist * k) +void klist_add_tail(struct klist_node *n, struct klist *k) { klist_node_init(k, n); add_tail(k, n); } - EXPORT_SYMBOL_GPL(klist_add_tail); - /** * klist_add_after - Init a klist_node and add it after an existing node * @n: node we're adding. @@ -152,30 +140,27 @@ void klist_add_before(struct klist_node *n, struct klist_node *pos) } EXPORT_SYMBOL_GPL(klist_add_before); - -static void klist_release(struct kref * kref) +static void klist_release(struct kref *kref) { - struct klist_node * n = container_of(kref, struct klist_node, n_ref); + struct klist_node *n = container_of(kref, struct klist_node, n_ref); list_del(&n->n_node); complete(&n->n_removed); n->n_klist = NULL; } -static int klist_dec_and_del(struct klist_node * n) +static int klist_dec_and_del(struct klist_node *n) { return kref_put(&n->n_ref, klist_release); } - /** - * klist_del - Decrement the reference count of node and try to remove. - * @n: node we're deleting. + * klist_del - Decrement the reference count of node and try to remove. + * @n: node we're deleting. */ - -void klist_del(struct klist_node * n) +void klist_del(struct klist_node *n) { - struct klist * k = n->n_klist; + struct klist *k = n->n_klist; void (*put)(struct klist_node *) = k->put; spin_lock(&k->k_lock); @@ -185,48 +170,40 @@ void klist_del(struct klist_node * n) if (put) put(n); } - EXPORT_SYMBOL_GPL(klist_del); - /** - * klist_remove - Decrement the refcount of node and wait for it to go away. - * @n: node we're removing. + * klist_remove - Decrement the refcount of node and wait for it to go away. + * @n: node we're removing. */ - -void klist_remove(struct klist_node * n) +void klist_remove(struct klist_node *n) { klist_del(n); wait_for_completion(&n->n_removed); } - EXPORT_SYMBOL_GPL(klist_remove); - /** - * klist_node_attached - Say whether a node is bound to a list or not. - * @n: Node that we're testing. + * klist_node_attached - Say whether a node is bound to a list or not. + * @n: Node that we're testing. */ - -int klist_node_attached(struct klist_node * n) +int klist_node_attached(struct klist_node *n) { return (n->n_klist != NULL); } - EXPORT_SYMBOL_GPL(klist_node_attached); - /** - * klist_iter_init_node - Initialize a klist_iter structure. - * @k: klist we're iterating. - * @i: klist_iter we're filling. - * @n: node to start with. + * klist_iter_init_node - Initialize a klist_iter structure. + * @k: klist we're iterating. + * @i: klist_iter we're filling. + * @n: node to start with. * - * Similar to klist_iter_init(), but starts the action off with @n, - * instead of with the list head. + * Similar to klist_iter_init(), but starts the action off with @n, + * instead of with the list head. */ - -void klist_iter_init_node(struct klist * k, struct klist_iter * i, struct klist_node * n) +void klist_iter_init_node(struct klist *k, struct klist_iter *i, + struct klist_node *n) { i->i_klist = k; i->i_head = &k->k_list; @@ -234,66 +211,56 @@ void klist_iter_init_node(struct klist * k, struct klist_iter * i, struct klist_ if (n) kref_get(&n->n_ref); } - EXPORT_SYMBOL_GPL(klist_iter_init_node); - /** - * klist_iter_init - Iniitalize a klist_iter structure. - * @k: klist we're iterating. - * @i: klist_iter structure we're filling. + * klist_iter_init - Iniitalize a klist_iter structure. + * @k: klist we're iterating. + * @i: klist_iter structure we're filling. * - * Similar to klist_iter_init_node(), but start with the list head. + * Similar to klist_iter_init_node(), but start with the list head. */ - -void klist_iter_init(struct klist * k, struct klist_iter * i) +void klist_iter_init(struct klist *k, struct klist_iter *i) { klist_iter_init_node(k, i, NULL); } - EXPORT_SYMBOL_GPL(klist_iter_init); - /** - * klist_iter_exit - Finish a list iteration. - * @i: Iterator structure. + * klist_iter_exit - Finish a list iteration. + * @i: Iterator structure. * - * Must be called when done iterating over list, as it decrements the - * refcount of the current node. Necessary in case iteration exited before - * the end of the list was reached, and always good form. + * Must be called when done iterating over list, as it decrements the + * refcount of the current node. Necessary in case iteration exited before + * the end of the list was reached, and always good form. */ - -void klist_iter_exit(struct klist_iter * i) +void klist_iter_exit(struct klist_iter *i) { if (i->i_cur) { klist_del(i->i_cur); i->i_cur = NULL; } } - EXPORT_SYMBOL_GPL(klist_iter_exit); - -static struct klist_node * to_klist_node(struct list_head * n) +static struct klist_node *to_klist_node(struct list_head *n) { return container_of(n, struct klist_node, n_node); } - /** - * klist_next - Ante up next node in list. - * @i: Iterator structure. + * klist_next - Ante up next node in list. + * @i: Iterator structure. * - * First grab list lock. Decrement the reference count of the previous - * node, if there was one. Grab the next node, increment its reference - * count, drop the lock, and return that next node. + * First grab list lock. Decrement the reference count of the previous + * node, if there was one. Grab the next node, increment its reference + * count, drop the lock, and return that next node. */ - -struct klist_node * klist_next(struct klist_iter * i) +struct klist_node *klist_next(struct klist_iter *i) { - struct list_head * next; - struct klist_node * lnode = i->i_cur; - struct klist_node * knode = NULL; + struct list_head *next; + struct klist_node *lnode = i->i_cur; + struct klist_node *knode = NULL; void (*put)(struct klist_node *) = i->i_klist->put; spin_lock(&i->i_klist->k_lock); @@ -314,7 +281,4 @@ struct klist_node * klist_next(struct klist_iter * i) put(lnode); return knode; } - EXPORT_SYMBOL_GPL(klist_next); - - |