Viewing file:  rculist.h (28.56 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_RCULIST_H
#define _LINUX_RCULIST_H
#ifdef __KERNEL__
/*
* RCU-protected list version
*/
#include <linux/list.h>
#include <linux/rcupdate.h>
/*
* INIT_LIST_HEAD_RCU - Initialize a list_head visible to RCU readers
* @list: list to be initialized
*
* You should instead use INIT_LIST_HEAD() for normal initialization and
* cleanup tasks, when readers have no access to the list being initialized.
* However, if the list being initialized is visible to readers, you
* need to keep the compiler from being too mischievous.
*/
static inline void INIT_LIST_HEAD_RCU(struct list_head *list)
{
WRITE_ONCE(list->next, list);
WRITE_ONCE(list->prev, list);
}
/*
* return the ->next pointer of a list_head in an rcu safe
* way, we must not access it directly
*/
#define list_next_rcu(list) (*((struct list_head __rcu **)(&(list)->next)))
/**
* list_tail_rcu - returns the prev pointer of the head of the list
* @head: the head of the list
*
* Note: This should only be used with the list header, and even then
* only if list_del() and similar primitives are not also used on the
* list header.
*/
#define list_tail_rcu(head) (*((struct list_head __rcu **)(&(head)->prev)))
/*
* Check during list traversal that we are within an RCU reader
*/
#define check_arg_count_one(dummy)
#ifdef CONFIG_PROVE_RCU_LIST
#define __list_check_rcu(dummy, cond, extra...) \
({ \
check_arg_count_one(extra); \
RCU_LOCKDEP_WARN(!(cond) && !rcu_read_lock_any_held(), \
"RCU-list traversed in non-reader section!"); \
})
#define __list_check_srcu(cond) \
({ \
RCU_LOCKDEP_WARN(!(cond), \
"RCU-list traversed without holding the required lock!");\
})
#else
#define __list_check_rcu(dummy, cond, extra...) \
({ check_arg_count_one(extra); })
#define __list_check_srcu(cond) ({ })
#endif
/*
* 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_rcu(struct list_head *new,
struct list_head *prev, struct list_head *next)
{
if (!__list_add_valid(new, prev, next))
return;
new->next = next;
new->prev = prev;
rcu_assign_pointer(list_next_rcu(prev), new);
next->prev = new;
}
/**
* list_add_rcu - add a new entry to rcu-protected list
* @new: new entry to be added
* @head: list head to add it after
*
* Insert a new entry after the specified head.
* This is good for implementing stacks.
*
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as list_add_rcu()
* or list_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
* list_for_each_entry_rcu().
*/
static inline void list_add_rcu(struct list_head *new, struct list_head *head)
{
__list_add_rcu(new, head, head->next);
}
/**
* list_add_tail_rcu - add a new entry to rcu-protected list
* @new: new entry to be added
* @head: list head to add it before
*
* Insert a new entry before the specified head.
* This is useful for implementing queues.
*
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as list_add_tail_rcu()
* or list_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
* list_for_each_entry_rcu().
*/
static inline void list_add_tail_rcu(struct list_head *new,
struct list_head *head)
{
__list_add_rcu(new, head->prev, head);
}
/**
* list_del_rcu - deletes entry from list without re-initialization
* @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. It is useful for RCU based
* lockfree traversal.
*
* In particular, it means that we can not poison the forward
* pointers that may still be used for walking the list.
*
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as list_del_rcu()
* or list_add_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
* list_for_each_entry_rcu().
*
* Note that the caller is not permitted to immediately free
* the newly deleted entry. Instead, either synchronize_rcu()
* or call_rcu() must be used to defer freeing until an RCU
* grace period has elapsed.
*/
static inline void list_del_rcu(struct list_head *entry)
{
__list_del_entry(entry);
entry->prev = LIST_POISON2;
}
/**
* hlist_del_init_rcu - deletes entry from hash list with re-initialization
* @n: the element to delete from the hash list.
*
* Note: list_unhashed() on the node return true after this. It is
* useful for RCU based read lockfree traversal if the writer side
* must know if the list entry is still hashed or already unhashed.
*
* In particular, it means that we can not poison the forward pointers
* that may still be used for walking the hash list and we can only
* zero the pprev pointer so list_unhashed() will return true after
* this.
*
* The caller must take whatever precautions are necessary (such as
* holding appropriate locks) to avoid racing with another
* list-mutation primitive, such as hlist_add_head_rcu() or
* hlist_del_rcu(), running on this same list. However, it is
* perfectly legal to run concurrently with the _rcu list-traversal
* primitives, such as hlist_for_each_entry_rcu().
*/
static inline void hlist_del_init_rcu(struct hlist_node *n)
{
if (!hlist_unhashed(n)) {
__hlist_del(n);
WRITE_ONCE(n->pprev, NULL);
}
}
/**
* list_replace_rcu - replace old entry by new one
* @old : the element to be replaced
* @new : the new element to insert
*
* The @old entry will be replaced with the @new entry atomically.
* Note: @old should not be empty.
*/
static inline void list_replace_rcu(struct list_head *old,
struct list_head *new)
{
new->next = old->next;
new->prev = old->prev;
rcu_assign_pointer(list_next_rcu(new->prev), new);
new->next->prev = new;
old->prev = LIST_POISON2;
}
/**
* __list_splice_init_rcu - join an RCU-protected list into an existing list.
* @list: the RCU-protected list to splice
* @prev: points to the last element of the existing list
* @next: points to the first element of the existing list
* @sync: synchronize_rcu, synchronize_rcu_expedited, ...
*
* The list pointed to by @prev and @next can be RCU-read traversed
* concurrently with this function.
*
* Note that this function blocks.
*
* Important note: the caller must take whatever action is necessary to prevent
* any other updates to the existing list. In principle, it is possible to
* modify the list as soon as sync() begins execution. If this sort of thing
* becomes necessary, an alternative version based on call_rcu() could be
* created. But only if -really- needed -- there is no shortage of RCU API
* members.
*/
static inline void __list_splice_init_rcu(struct list_head *list,
struct list_head *prev,
struct list_head *next,
void (*sync)(void))
{
struct list_head *first = list->next;
struct list_head *last = list->prev;
/*
* "first" and "last" tracking list, so initialize it. RCU readers
* have access to this list, so we must use INIT_LIST_HEAD_RCU()
* instead of INIT_LIST_HEAD().
*/
INIT_LIST_HEAD_RCU(list);
/*
* At this point, the list body still points to the source list.
* Wait for any readers to finish using the list before splicing
* the list body into the new list. Any new readers will see
* an empty list.
*/
sync();
ASSERT_EXCLUSIVE_ACCESS(*first);
ASSERT_EXCLUSIVE_ACCESS(*last);
/*
* Readers are finished with the source list, so perform splice.
* The order is important if the new list is global and accessible
* to concurrent RCU readers. Note that RCU readers are not
* permitted to traverse the prev pointers without excluding
* this function.
*/
last->next = next;
rcu_assign_pointer(list_next_rcu(prev), first);
first->prev = prev;
next->prev = last;
}
/**
* list_splice_init_rcu - splice an RCU-protected list into an existing list,
* designed for stacks.
* @list: the RCU-protected list to splice
* @head: the place in the existing list to splice the first list into
* @sync: synchronize_rcu, synchronize_rcu_expedited, ...
*/
static inline void list_splice_init_rcu(struct list_head *list,
struct list_head *head,
void (*sync)(void))
{
if (!list_empty(list))
__list_splice_init_rcu(list, head, head->next, sync);
}
/**
* list_splice_tail_init_rcu - splice an RCU-protected list into an existing
* list, designed for queues.
* @list: the RCU-protected list to splice
* @head: the place in the existing list to splice the first list into
* @sync: synchronize_rcu, synchronize_rcu_expedited, ...
*/
static inline void list_splice_tail_init_rcu(struct list_head *list,
struct list_head *head,
void (*sync)(void))
{
if (!list_empty(list))
__list_splice_init_rcu(list, head->prev, head, sync);
}
/**
* list_entry_rcu - get the struct for this entry
* @ptr: the &struct list_head pointer.
* @type: the type of the struct this is embedded in.
* @member: the name of the list_head within the struct.
*
* This primitive may safely run concurrently with the _rcu list-mutation
* primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
*/
#define list_entry_rcu(ptr, type, member) \
container_of(READ_ONCE(ptr), type, member)
/*
* Where are list_empty_rcu() and list_first_entry_rcu()?
*
* They do not exist because they would lead to subtle race conditions:
*
* if (!list_empty_rcu(mylist)) {
* struct foo *bar = list_first_entry_rcu(mylist, struct foo, list_member);
* do_something(bar);
* }
*
* The list might be non-empty when list_empty_rcu() checks it, but it
* might have become empty by the time that list_first_entry_rcu() rereads
* the ->next pointer, which would result in a SEGV.
*
* When not using RCU, it is OK for list_first_entry() to re-read that
* pointer because both functions should be protected by some lock that
* blocks writers.
*
* When using RCU, list_empty() uses READ_ONCE() to fetch the
* RCU-protected ->next pointer and then compares it to the address of the
* list head. However, it neither dereferences this pointer nor provides
* this pointer to its caller. Thus, READ_ONCE() suffices (that is,
* rcu_dereference() is not needed), which means that list_empty() can be
* used anywhere you would want to use list_empty_rcu(). Just don't
* expect anything useful to happen if you do a subsequent lockless
* call to list_first_entry_rcu()!!!
*
* See list_first_or_null_rcu for an alternative.
*/
/**
* list_first_or_null_rcu - 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 if the list is empty, it returns NULL.
*
* This primitive may safely run concurrently with the _rcu list-mutation
* primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
*/
#define list_first_or_null_rcu(ptr, type, member) \
({ \
struct list_head *__ptr = (ptr); \
struct list_head *__next = READ_ONCE(__ptr->next); \
likely(__ptr != __next) ? list_entry_rcu(__next, type, member) : NULL; \
})
/**
* list_next_or_null_rcu - get the first element from a list
* @head: the head for the list.
* @ptr: the list head to take the next element from.
* @type: the type of the struct this is embedded in.
* @member: the name of the list_head within the struct.
*
* Note that if the ptr is at the end of the list, NULL is returned.
*
* This primitive may safely run concurrently with the _rcu list-mutation
* primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
*/
#define list_next_or_null_rcu(head, ptr, type, member) \
({ \
struct list_head *__head = (head); \
struct list_head *__ptr = (ptr); \
struct list_head *__next = READ_ONCE(__ptr->next); \
likely(__next != __head) ? list_entry_rcu(__next, type, \
member) : NULL; \
})
/**
* list_for_each_entry_rcu - iterate over rcu list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the list_head within the struct.
* @cond: optional lockdep expression if called from non-RCU protection.
*
* This list-traversal primitive may safely run concurrently with
* the _rcu list-mutation primitives such as list_add_rcu()
* as long as the traversal is guarded by rcu_read_lock().
*/
#define list_for_each_entry_rcu(pos, head, member, cond...) \
for (__list_check_rcu(dummy, ## cond, 0), \
pos = list_entry_rcu((head)->next, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry_rcu(pos->member.next, typeof(*pos), member))
/**
* list_for_each_entry_srcu - iterate over rcu list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the list_head within the struct.
* @cond: lockdep expression for the lock required to traverse the list.
*
* This list-traversal primitive may safely run concurrently with
* the _rcu list-mutation primitives such as list_add_rcu()
* as long as the traversal is guarded by srcu_read_lock().
* The lockdep expression srcu_read_lock_held() can be passed as the
* cond argument from read side.
*/
#define list_for_each_entry_srcu(pos, head, member, cond) \
for (__list_check_srcu(cond), \
pos = list_entry_rcu((head)->next, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry_rcu(pos->member.next, typeof(*pos), member))
/**
* list_entry_lockless - get the struct for this entry
* @ptr: the &struct list_head pointer.
* @type: the type of the struct this is embedded in.
* @member: the name of the list_head within the struct.
*
* This primitive may safely run concurrently with the _rcu
* list-mutation primitives such as list_add_rcu(), but requires some
* implicit RCU read-side guarding. One example is running within a special
* exception-time environment where preemption is disabled and where lockdep
* cannot be invoked. Another example is when items are added to the list,
* but never deleted.
*/
#define list_entry_lockless(ptr, type, member) \
container_of((typeof(ptr))READ_ONCE(ptr), type, member)
/**
* list_for_each_entry_lockless - iterate over rcu list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*
* This primitive may safely run concurrently with the _rcu
* list-mutation primitives such as list_add_rcu(), but requires some
* implicit RCU read-side guarding. One example is running within a special
* exception-time environment where preemption is disabled and where lockdep
* cannot be invoked. Another example is when items are added to the list,
* but never deleted.
*/
#define list_for_each_entry_lockless(pos, head, member) \
for (pos = list_entry_lockless((head)->next, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry_lockless(pos->member.next, typeof(*pos), member))
/**
* list_for_each_entry_continue_rcu - continue iteration over list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the list_head within the struct.
*
* Continue to iterate over list of given type, continuing after
* the current position which must have been in the list when the RCU read
* lock was taken.
* This would typically require either that you obtained the node from a
* previous walk of the list in the same RCU read-side critical section, or
* that you held some sort of non-RCU reference (such as a reference count)
* to keep the node alive *and* in the list.
*
* This iterator is similar to list_for_each_entry_from_rcu() except
* this starts after the given position and that one starts at the given
* position.
*/
#define list_for_each_entry_continue_rcu(pos, head, member) \
for (pos = list_entry_rcu(pos->member.next, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry_rcu(pos->member.next, typeof(*pos), member))
/**
* list_for_each_entry_from_rcu - iterate over a list from current point
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the list_node within the struct.
*
* Iterate over the tail of a list starting from a given position,
* which must have been in the list when the RCU read lock was taken.
* This would typically require either that you obtained the node from a
* previous walk of the list in the same RCU read-side critical section, or
* that you held some sort of non-RCU reference (such as a reference count)
* to keep the node alive *and* in the list.
*
* This iterator is similar to list_for_each_entry_continue_rcu() except
* this starts from the given position and that one starts from the position
* after the given position.
*/
#define list_for_each_entry_from_rcu(pos, head, member) \
for (; &(pos)->member != (head); \
pos = list_entry_rcu(pos->member.next, typeof(*(pos)), member))
/**
* hlist_del_rcu - deletes entry from hash list without re-initialization
* @n: the element to delete from the hash list.
*
* Note: list_unhashed() on entry does not return true after this,
* the entry is in an undefined state. It is useful for RCU based
* lockfree traversal.
*
* In particular, it means that we can not poison the forward
* pointers that may still be used for walking the hash list.
*
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as hlist_add_head_rcu()
* or hlist_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
* hlist_for_each_entry().
*/
static inline void hlist_del_rcu(struct hlist_node *n)
{
__hlist_del(n);
WRITE_ONCE(n->pprev, LIST_POISON2);
}
/**
* hlist_replace_rcu - replace old entry by new one
* @old : the element to be replaced
* @new : the new element to insert
*
* The @old entry will be replaced with the @new entry atomically.
*/
static inline void hlist_replace_rcu(struct hlist_node *old,
struct hlist_node *new)
{
struct hlist_node *next = old->next;
new->next = next;
WRITE_ONCE(new->pprev, old->pprev);
rcu_assign_pointer(*(struct hlist_node __rcu **)new->pprev, new);
if (next)
WRITE_ONCE(new->next->pprev, &new->next);
WRITE_ONCE(old->pprev, LIST_POISON2);
}
/**
* hlists_swap_heads_rcu - swap the lists the hlist heads point to
* @left: The hlist head on the left
* @right: The hlist head on the right
*
* The lists start out as [@left ][node1 ... ] and
* [@right ][node2 ... ]
* The lists end up as [@left ][node2 ... ]
* [@right ][node1 ... ]
*/
static inline void hlists_swap_heads_rcu(struct hlist_head *left, struct hlist_head *right)
{
struct hlist_node *node1 = left->first;
struct hlist_node *node2 = right->first;
rcu_assign_pointer(left->first, node2);
rcu_assign_pointer(right->first, node1);
WRITE_ONCE(node2->pprev, &left->first);
WRITE_ONCE(node1->pprev, &right->first);
}
/*
* return the first or the next element in an RCU protected hlist
*/
#define hlist_first_rcu(head) (*((struct hlist_node __rcu **)(&(head)->first)))
#define hlist_next_rcu(node) (*((struct hlist_node __rcu **)(&(node)->next)))
#define hlist_pprev_rcu(node) (*((struct hlist_node __rcu **)((node)->pprev)))
/**
* hlist_add_head_rcu
* @n: the element to add to the hash list.
* @h: the list to add to.
*
* Description:
* Adds the specified element to the specified hlist,
* while permitting racing traversals.
*
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as hlist_add_head_rcu()
* or hlist_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
* hlist_for_each_entry_rcu(), used to prevent memory-consistency
* problems on Alpha CPUs. Regardless of the type of CPU, the
* list-traversal primitive must be guarded by rcu_read_lock().
*/
static inline void hlist_add_head_rcu(struct hlist_node *n,
struct hlist_head *h)
{
struct hlist_node *first = h->first;
n->next = first;
WRITE_ONCE(n->pprev, &h->first);
rcu_assign_pointer(hlist_first_rcu(h), n);
if (first)
WRITE_ONCE(first->pprev, &n->next);
}
/**
* hlist_add_tail_rcu
* @n: the element to add to the hash list.
* @h: the list to add to.
*
* Description:
* Adds the specified element to the specified hlist,
* while permitting racing traversals.
*
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as hlist_add_head_rcu()
* or hlist_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
* hlist_for_each_entry_rcu(), used to prevent memory-consistency
* problems on Alpha CPUs. Regardless of the type of CPU, the
* list-traversal primitive must be guarded by rcu_read_lock().
*/
static inline void hlist_add_tail_rcu(struct hlist_node *n,
struct hlist_head *h)
{
struct hlist_node *i, *last = NULL;
/* Note: write side code, so rcu accessors are not needed. */
for (i = h->first; i; i = i->next)
last = i;
if (last) {
n->next = last->next;
WRITE_ONCE(n->pprev, &last->next);
rcu_assign_pointer(hlist_next_rcu(last), n);
} else {
hlist_add_head_rcu(n, h);
}
}
/**
* hlist_add_before_rcu
* @n: the new element to add to the hash list.
* @next: the existing element to add the new element before.
*
* Description:
* Adds the specified element to the specified hlist
* before the specified node while permitting racing traversals.
*
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as hlist_add_head_rcu()
* or hlist_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
* hlist_for_each_entry_rcu(), used to prevent memory-consistency
* problems on Alpha CPUs.
*/
static inline void hlist_add_before_rcu(struct hlist_node *n,
struct hlist_node *next)
{
WRITE_ONCE(n->pprev, next->pprev);
n->next = next;
rcu_assign_pointer(hlist_pprev_rcu(n), n);
WRITE_ONCE(next->pprev, &n->next);
}
/**
* hlist_add_behind_rcu
* @n: the new element to add to the hash list.
* @prev: the existing element to add the new element after.
*
* Description:
* Adds the specified element to the specified hlist
* after the specified node while permitting racing traversals.
*
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as hlist_add_head_rcu()
* or hlist_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
* hlist_for_each_entry_rcu(), used to prevent memory-consistency
* problems on Alpha CPUs.
*/
static inline void hlist_add_behind_rcu(struct hlist_node *n,
struct hlist_node *prev)
{
n->next = prev->next;
WRITE_ONCE(n->pprev, &prev->next);
rcu_assign_pointer(hlist_next_rcu(prev), n);
if (n->next)
WRITE_ONCE(n->next->pprev, &n->next);
}
#define __hlist_for_each_rcu(pos, head) \
for (pos = rcu_dereference(hlist_first_rcu(head)); \
pos; \
pos = rcu_dereference(hlist_next_rcu(pos)))
/**
* hlist_for_each_entry_rcu - iterate over rcu list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
* @cond: optional lockdep expression if called from non-RCU protection.
*
* This list-traversal primitive may safely run concurrently with
* the _rcu list-mutation primitives such as hlist_add_head_rcu()
* as long as the traversal is guarded by rcu_read_lock().
*/
#define hlist_for_each_entry_rcu(pos, head, member, cond...) \
for (__list_check_rcu(dummy, ## cond, 0), \
pos = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),\
typeof(*(pos)), member); \
pos; \
pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(\
&(pos)->member)), typeof(*(pos)), member))
/**
* hlist_for_each_entry_srcu - iterate over rcu list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
* @cond: lockdep expression for the lock required to traverse the list.
*
* This list-traversal primitive may safely run concurrently with
* the _rcu list-mutation primitives such as hlist_add_head_rcu()
* as long as the traversal is guarded by srcu_read_lock().
* The lockdep expression srcu_read_lock_held() can be passed as the
* cond argument from read side.
*/
#define hlist_for_each_entry_srcu(pos, head, member, cond) \
for (__list_check_srcu(cond), \
pos = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),\
typeof(*(pos)), member); \
pos; \
pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(\
&(pos)->member)), typeof(*(pos)), member))
/**
* hlist_for_each_entry_rcu_notrace - iterate over rcu list of given type (for tracing)
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*
* This list-traversal primitive may safely run concurrently with
* the _rcu list-mutation primitives such as hlist_add_head_rcu()
* as long as the traversal is guarded by rcu_read_lock().
*
* This is the same as hlist_for_each_entry_rcu() except that it does
* not do any RCU debugging or tracing.
*/
#define hlist_for_each_entry_rcu_notrace(pos, head, member) \
for (pos = hlist_entry_safe(rcu_dereference_raw_check(hlist_first_rcu(head)),\
typeof(*(pos)), member); \
pos; \
pos = hlist_entry_safe(rcu_dereference_raw_check(hlist_next_rcu(\
&(pos)->member)), typeof(*(pos)), member))
/**
* hlist_for_each_entry_rcu_bh - iterate over rcu list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*
* This list-traversal primitive may safely run concurrently with
* the _rcu list-mutation primitives such as hlist_add_head_rcu()
* as long as the traversal is guarded by rcu_read_lock().
*/
#define hlist_for_each_entry_rcu_bh(pos, head, member) \
for (pos = hlist_entry_safe(rcu_dereference_bh(hlist_first_rcu(head)),\
typeof(*(pos)), member); \
pos; \
pos = hlist_entry_safe(rcu_dereference_bh(hlist_next_rcu(\
&(pos)->member)), typeof(*(pos)), member))
/**
* hlist_for_each_entry_continue_rcu - iterate over a hlist continuing after current point
* @pos: the type * to use as a loop cursor.
* @member: the name of the hlist_node within the struct.
*/
#define hlist_for_each_entry_continue_rcu(pos, member) \
for (pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu( \
&(pos)->member)), typeof(*(pos)), member); \
pos; \
pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu( \
&(pos)->member)), typeof(*(pos)), member))
/**
* hlist_for_each_entry_continue_rcu_bh - iterate over a hlist continuing after current point
* @pos: the type * to use as a loop cursor.
* @member: the name of the hlist_node within the struct.
*/
#define hlist_for_each_entry_continue_rcu_bh(pos, member) \
for (pos = hlist_entry_safe(rcu_dereference_bh(hlist_next_rcu( \
&(pos)->member)), typeof(*(pos)), member); \
pos; \
pos = hlist_entry_safe(rcu_dereference_bh(hlist_next_rcu( \
&(pos)->member)), typeof(*(pos)), member))
/**
* hlist_for_each_entry_from_rcu - iterate over a hlist continuing from current point
* @pos: the type * to use as a loop cursor.
* @member: the name of the hlist_node within the struct.
*/
#define hlist_for_each_entry_from_rcu(pos, member) \
for (; pos; \
pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu( \
&(pos)->member)), typeof(*(pos)), member))
#endif /* __KERNEL__ */
#endif
|