autofs-5.1.6 - update list.h From: Ian Kent Update autofs include/list.h mostly to include the hlist implementation but also to simplify bits of it. Signed-off-by: Ian Kent --- CHANGELOG | 1 include/list.h | 402 +++++++++++++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 378 insertions(+), 25 deletions(-) diff --git a/CHANGELOG b/CHANGELOG index 14d66f34..70851683 100644 --- a/CHANGELOG +++ b/CHANGELOG @@ -50,6 +50,7 @@ xx/xx/2020 autofs-5.1.7 - add force unlink mounts and exit option. - cleanup stale logpri fifo pipes on unlink and exit. - fix incorrect systemctl command syntax in autofs(8). +- update list.h. 07/10/2019 autofs-5.1.6 - support strictexpire mount option. diff --git a/include/list.h b/include/list.h index 516c4d08..53ab1bf5 100644 --- a/include/list.h +++ b/include/list.h @@ -1,6 +1,27 @@ #ifndef _LINUX_LIST_H #define _LINUX_LIST_H +#include + +/* + * Casts a member of a structure out to the containing structure + * @param ptr the pointer to the member. + * @param type the type of the container struct this is embedded in. + * @param member the name of the member within the struct. + * + */ +#define container_of(ptr, type, member) ({ \ + const typeof( ((type *)0)->member ) *__mptr = (ptr); \ + (type *)( (char *)__mptr - offsetof(type,member) );}) + +/* + * These are non-NULL pointers that will result in page faults + * under normal circumstances, used to verify that nobody uses + * non-initialized list entries. + */ +#define LIST_POISON1 ((void *) 0x00100100) +#define LIST_POISON2 ((void *) 0x00200200) + /* * Simple doubly linked list implementation. * @@ -25,14 +46,14 @@ struct list_head { } while (0) /* - * Insert a new entry between two known consecutive entries. + * Insert a new entry between two known consecutive entries. * * This is only for internal list manipulation where we know * the prev/next entries already! */ -static __inline__ void __list_add(struct list_head * new, - struct list_head * prev, - struct list_head * next) +static inline void __list_add(struct list_head *new, + struct list_head *prev, + struct list_head *next) { next->prev = new; new->next = next; @@ -48,7 +69,7 @@ static __inline__ void __list_add(struct list_head * new, * Insert a new entry after the specified head. * This is good for implementing stacks. */ -static __inline__ void list_add(struct list_head *new, struct list_head *head) +static inline void list_add(struct list_head *new, struct list_head *head) { __list_add(new, head, head->next); } @@ -61,7 +82,7 @@ static __inline__ void list_add(struct list_head *new, struct list_head *head) * Insert a new entry before the specified head. * This is useful for implementing queues. */ -static __inline__ void list_add_tail(struct list_head *new, struct list_head *head) +static inline void list_add_tail(struct list_head *new, struct list_head *head) { __list_add(new, head->prev, head); } @@ -73,8 +94,7 @@ static __inline__ void list_add_tail(struct list_head *new, struct list_head *he * This is only for internal list manipulation where we know * the prev/next entries already! */ -static __inline__ void __list_del(struct list_head * prev, - struct list_head * next) +static inline void __list_del(struct list_head * prev, struct list_head * next) { next->prev = prev; prev->next = next; @@ -83,50 +103,96 @@ static __inline__ void __list_del(struct list_head * prev, /** * list_del - deletes entry from list. * @entry: the element to delete from the list. - * Note: list_empty on entry does not return true after this, the entry is in an undefined state. + * Note: list_empty on entry does not return true after this, the entry is + * in an undefined state. */ -static __inline__ void list_del(struct list_head *entry) +static inline void list_del(struct list_head *entry) { __list_del(entry->prev, entry->next); + entry->next = LIST_POISON1; + entry->prev = LIST_POISON2; } /** * list_del_init - deletes entry from list and reinitialize it. * @entry: the element to delete from the list. */ -static __inline__ void list_del_init(struct list_head *entry) +static inline void list_del_init(struct list_head *entry) { __list_del(entry->prev, entry->next); - INIT_LIST_HEAD(entry); + INIT_LIST_HEAD(entry); +} + +/* + * list_move - delete from one list and add as another's head + * @list: the entry to move + * @head: the head that will precede our entry + */ +static inline void list_move(struct list_head *list, struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add(list, head); +} + +/** + * list_move_tail - delete from one list and add as another's tail + * @list: the entry to move + * @head: the head that will follow our entry + */ +static inline void list_move_tail(struct list_head *list, + struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add_tail(list, head); } /** * list_empty - tests whether a list is empty * @head: the list to test. */ -static __inline__ int list_empty(struct list_head *head) +static inline int list_empty(const struct list_head *head) { return head->next == head; } +static inline void __list_splice(struct list_head *list, + struct list_head *head) +{ + struct list_head *first = list->next; + struct list_head *last = list->prev; + struct list_head *at = head->next; + + first->prev = head; + head->next = first; + + last->next = at; + at->prev = last; +} + /** * list_splice - join two lists * @list: the new list to add. * @head: the place to add it in the first list. */ -static __inline__ void list_splice(struct list_head *list, struct list_head *head) +static inline void list_splice(struct list_head *list, struct list_head *head) { - struct list_head *first = list->next; - - if (first != list) { - struct list_head *last = list->prev; - struct list_head *at = head->next; - - first->prev = head; - head->next = first; + if (!list_empty(list)) + __list_splice(list, head); +} - last->next = at; - at->prev = last; +/** + * list_splice_init - join two lists and reinitialise the emptied list. + * @list: the new list to add. + * @head: the place to add it in the first list. + * + * The list at @list is reinitialised + */ +static inline void list_splice_init(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) { + __list_splice(list, head); + INIT_LIST_HEAD(list); } } @@ -137,7 +203,45 @@ static __inline__ void list_splice(struct list_head *list, struct list_head *hea * @member: the name of the list_struct within the struct. */ #define list_entry(ptr, type, member) \ - ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) + container_of(ptr, type, member) + +/** + * list_first_entry - get the first element from a list + * @ptr: the list head to take the element from. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_head within the struct. + * + * Note, that list is expected to be not empty. + */ +#define list_first_entry(ptr, type, member) \ + list_entry((ptr)->next, type, member) + +/** + * list_last_entry - get the last element from a list + * @ptr: the list head to take the element from. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_head within the struct. + * + * Note, that list is expected to be not empty. + */ +#define list_last_entry(ptr, type, member) \ + list_entry((ptr)->prev, type, member) + +/** + * list_next_entry - get the next element in list + * @pos: the type * to cursor + * @member: the name of the list_head within the struct. + */ +#define list_next_entry(pos, member) \ + list_entry((pos)->member.next, typeof(*(pos)), member) + +/** + * list_prev_entry - get the prev element in list + * @pos: the type * to cursor + * @member: the name of the list_head within the struct. + */ +#define list_prev_entry(pos, member) \ + list_entry((pos)->member.prev, typeof(*(pos)), member) /** * list_for_each - iterate over a list @@ -155,4 +259,252 @@ static __inline__ void list_splice(struct list_head *list, struct list_head *hea #define list_for_each_prev(pos, head) \ for (pos = (head)->prev; pos != (head); pos = pos->prev) +/** + * list_for_each_safe - iterate over a list safe against removal of list entry + * @pos: the &struct list_head to use as a loop counter. + * @n: another &struct list_head to use as temporary storage + * @head: the head for your list. + */ +#define list_for_each_safe(pos, n, head) \ + for (pos = (head)->next, n = pos->next; pos != (head); \ + pos = n, n = pos->next) + +/** + * list_for_each_entry - iterate over list of given type + * @pos: the type * to use as a loop counter. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry(pos, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_next_entry(pos, member)) + +/** + * list_for_each_entry_reverse - iterate backwards over list of given type. + * @pos: the type * to use as a loop counter. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_reverse(pos, head, member) \ + for (pos = list_last_entry(head, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_prev_entry(pos, member)) + +/** + * list_prepare_entry - prepare a pos entry for use as a start point in + * list_for_each_entry_continue + * @pos: the type * to use as a start point + * @head: the head of the list + * @member: the name of the list_struct within the struct. + */ +#define list_prepare_entry(pos, head, member) \ + ((pos) ? : list_entry(head, typeof(*pos), member)) + +/** + * list_for_each_entry_continue - iterate over list of given type + * continuing after existing point + * @pos: the type * to use as a loop counter. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_continue(pos, head, member) \ + for (pos = list_next_entry(pos, member); \ + &pos->member != (head); \ + pos = list_next_entry(pos, member)) + +/** + * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry + * @pos: the type * to use as a loop counter. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_safe(pos, n, head, member) \ + for (pos = list_first_entry(head, typeof(*pos), member), \ + n = list_next_entry(pos, member); \ + &pos->member != (head); \ + pos = n, n = list_next_entry(n, member)) + +/** + * list_for_each_entry_safe_continue - iterate over list of given type + * continuing after existing point safe against removal of list entry + * @pos: the type * to use as a loop counter. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_safe_continue(pos, n, head, member) \ + for (pos = list_next_entry(pos, member), \ + n = list_next_entry(pos, member); \ + &pos->member != (head); \ + pos = n, n = list_next_entry(n, member)) + +/** + * list_for_each_entry_safe_reverse - iterate backwards over list of given type safe against + * removal of list entry + * @pos: the type * to use as a loop counter. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_safe_reverse(pos, n, head, member) \ + for (pos = list_last_entry(head, typeof(*pos), member), \ + n = list_prev_entry(pos, member); \ + &pos->member != (head); \ + pos = n, n = list_prev_entry(n, member)) + + + + +/* + * Double linked lists with a single pointer list head. + * Mostly useful for hash tables where the two pointer list head is + * too wasteful. + * You lose the ability to access the tail in O(1). + */ + +struct hlist_head { + struct hlist_node *first; +}; + +struct hlist_node { + struct hlist_node *next, **pprev; +}; + +#define HLIST_HEAD_INIT { .first = NULL } +#define HLIST_HEAD(name) struct hlist_head name = { .first = NULL } +#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL) +#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL) + +static inline int hlist_unhashed(const struct hlist_node *h) +{ + return !h->pprev; +} + +static inline int hlist_empty(const struct hlist_head *h) +{ + return !h->first; +} + +static inline void __hlist_del(struct hlist_node *n) +{ + struct hlist_node *next = n->next; + struct hlist_node **pprev = n->pprev; + *pprev = next; + if (next) + next->pprev = pprev; +} + +static inline void hlist_del(struct hlist_node *n) +{ + __hlist_del(n); + n->next = LIST_POISON1; + n->pprev = LIST_POISON2; +} + + +static inline void hlist_del_init(struct hlist_node *n) +{ + if (n->pprev) { + __hlist_del(n); + INIT_HLIST_NODE(n); + } +} + +static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h) +{ + struct hlist_node *first = h->first; + n->next = first; + if (first) + first->pprev = &n->next; + h->first = n; + n->pprev = &h->first; +} + + + +/* next must be != NULL */ +static inline void hlist_add_before(struct hlist_node *n, + struct hlist_node *next) +{ + n->pprev = next->pprev; + n->next = next; + next->pprev = &n->next; + *(n->pprev) = n; +} + +static inline void hlist_add_after(struct hlist_node *n, + struct hlist_node *next) +{ + next->next = n->next; + n->next = next; + next->pprev = &n->next; + + if(next->next) + next->next->pprev = &next->next; +} + + + +#define hlist_entry(ptr, type, member) container_of(ptr,type,member) + +#define hlist_for_each(pos, head) \ + for (pos = (head)->first; pos; pos = pos->next) + +#define hlist_for_each_safe(pos, n, head) \ + for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \ + pos = n) + +#define hlist_entry_safe(ptr, type, member) \ + ({ typeof(ptr) ____ptr = (ptr); \ + ____ptr ? hlist_entry(____ptr, type, member) : NULL; \ + }) + +/** + * hlist_for_each_entry - iterate over list of given type + * @tpos: the type * to use as a loop counter. + * @pos: the &struct hlist_node to use as a loop counter. + * @head: the head for your list. + * @member: the name of the hlist_node within the struct. + */ +#define hlist_for_each_entry(pos, head, member) \ + for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\ + pos; \ + pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) + +/** + * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point + * @tpos: the type * to use as a loop counter. + * @pos: the &struct hlist_node to use as a loop counter. + * @member: the name of the hlist_node within the struct. + */ +#define hlist_for_each_entry_continue(pos, member) \ + for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member);\ + pos; \ + pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) + +/** + * hlist_for_each_entry_from - iterate over a hlist continuing from existing point + * @tpos: the type * to use as a loop counter. + * @pos: the &struct hlist_node to use as a loop counter. + * @member: the name of the hlist_node within the struct. + */ +#define hlist_for_each_entry_from(pos, member) \ + for (; pos; \ + pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) + +/** + * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry + * @tpos: the type * to use as a loop counter. + * @pos: the &struct hlist_node to use as a loop counter. + * @n: another &struct hlist_node to use as temporary storage + * @head: the head for your list. + * @member: the name of the hlist_node within the struct. + */ +#define hlist_for_each_entry_safe(tpos, pos, n, head, member) \ + for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\ + pos && ({ n = pos->next; 1; }) && \ + pos = hlist_entry_safe(n, typeof(*pos), member)) + #endif