Introduce a handy list_first_entry macro
There are many places in the kernel where the construction like
foo = list_entry(head->next, struct foo_struct, list);
are used.
The code might look more descriptive and neat if using the macro
list_first_entry(head, type, member) \
list_entry((head)->next, type, member)
Here is the macro itself and the examples of its usage in the generic code.
If it will turn out to be useful, I can prepare the set of patches to
inject in into arch-specific code, drivers, networking, etc.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/dquot.c b/fs/dquot.c
index dcc5a58..3a99584 100644
--- a/fs/dquot.c
+++ b/fs/dquot.c
@@ -474,7 +474,7 @@
spin_lock(&dq_list_lock);
dirty = &dqopt->info[cnt].dqi_dirty_list;
while (!list_empty(dirty)) {
- dquot = list_entry(dirty->next, struct dquot, dq_dirty);
+ dquot = list_first_entry(dirty, struct dquot, dq_dirty);
/* Dirty and inactive can be only bad dquot... */
if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
clear_dquot_dirty(dquot);
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index d0b8606..b5c7ca5 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -453,7 +453,7 @@
mutex_lock(&epmutex);
while (!list_empty(lsthead)) {
- epi = list_entry(lsthead->next, struct epitem, fllink);
+ epi = list_first_entry(lsthead, struct epitem, fllink);
ep = epi->ep;
list_del_init(&epi->fllink);
@@ -1143,7 +1143,7 @@
if (nwait) {
while (!list_empty(lsthead)) {
- pwq = list_entry(lsthead->next, struct eppoll_entry, llink);
+ pwq = list_first_entry(lsthead, struct eppoll_entry, llink);
list_del_init(&pwq->llink);
remove_wait_queue(pwq->whead, &pwq->wait);
@@ -1359,7 +1359,7 @@
* read.
*/
for (eventcnt = 0; !list_empty(txlist) && eventcnt < maxevents;) {
- epi = list_entry(txlist->next, struct epitem, rdllink);
+ epi = list_first_entry(txlist, struct epitem, rdllink);
prefetch(epi->rdllink.next);
/*
diff --git a/fs/inode.c b/fs/inode.c
index 81508b0..410f235 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -275,7 +275,7 @@
while (!list_empty(head)) {
struct inode *inode;
- inode = list_entry(head->next, struct inode, i_list);
+ inode = list_first_entry(head, struct inode, i_list);
list_del(&inode->i_list);
if (inode->i_data.nrpages)
diff --git a/fs/inotify.c b/fs/inotify.c
index f5099d8..7457501 100644
--- a/fs/inotify.c
+++ b/fs/inotify.c
@@ -509,7 +509,7 @@
mutex_unlock(&ih->mutex);
break;
}
- watch = list_entry(watches->next, struct inotify_watch, h_list);
+ watch = list_first_entry(watches, struct inotify_watch, h_list);
get_inotify_watch(watch);
mutex_unlock(&ih->mutex);
diff --git a/fs/namespace.c b/fs/namespace.c
index c5b8810..72bb106 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -499,7 +499,7 @@
{
struct vfsmount *mnt;
while (!list_empty(head)) {
- mnt = list_entry(head->next, struct vfsmount, mnt_hash);
+ mnt = list_first_entry(head, struct vfsmount, mnt_hash);
list_del_init(&mnt->mnt_hash);
if (mnt->mnt_parent != mnt) {
struct dentry *dentry;
@@ -1177,7 +1177,7 @@
while (!list_empty(graveyard)) {
LIST_HEAD(umounts);
- mnt = list_entry(graveyard->next, struct vfsmount, mnt_expire);
+ mnt = list_first_entry(graveyard, struct vfsmount, mnt_expire);
list_del_init(&mnt->mnt_expire);
/* don't do anything if the namespace is dead - all the
diff --git a/fs/pnode.c b/fs/pnode.c
index 56aacea..89940f2 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -59,7 +59,7 @@
} else {
struct list_head *p = &mnt->mnt_slave_list;
while (!list_empty(p)) {
- slave_mnt = list_entry(p->next,
+ slave_mnt = list_first_entry(p,
struct vfsmount, mnt_slave);
list_del_init(&slave_mnt->mnt_slave);
slave_mnt->mnt_master = NULL;