f2fs: use list_for_each_entry{_safe} for simplyfying code

This patch use list_for_each_entry{_safe} instead of list_for_each{_safe} for
simplfying code.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index d877f46..4aa521a 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -308,16 +308,15 @@
 
 void add_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
 {
-	struct list_head *head, *this;
-	struct orphan_inode_entry *new = NULL, *orphan = NULL;
+	struct list_head *head;
+	struct orphan_inode_entry *new, *orphan;
 
 	new = f2fs_kmem_cache_alloc(orphan_entry_slab, GFP_ATOMIC);
 	new->ino = ino;
 
 	spin_lock(&sbi->orphan_inode_lock);
 	head = &sbi->orphan_inode_list;
-	list_for_each(this, head) {
-		orphan = list_entry(this, struct orphan_inode_entry, list);
+	list_for_each_entry(orphan, head, list) {
 		if (orphan->ino == ino) {
 			spin_unlock(&sbi->orphan_inode_lock);
 			kmem_cache_free(orphan_entry_slab, new);
@@ -326,14 +325,10 @@
 
 		if (orphan->ino > ino)
 			break;
-		orphan = NULL;
 	}
 
-	/* add new_oentry into list which is sorted by inode number */
-	if (orphan)
-		list_add(&new->list, this->prev);
-	else
-		list_add_tail(&new->list, head);
+	/* add new orphan entry into list which is sorted by inode number */
+	list_add_tail(&new->list, &orphan->list);
 	spin_unlock(&sbi->orphan_inode_lock);
 }
 
@@ -561,14 +556,12 @@
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	struct list_head *head = &sbi->dir_inode_list;
-	struct list_head *this;
+	struct dir_inode_entry *entry;
 
-	list_for_each(this, head) {
-		struct dir_inode_entry *entry;
-		entry = list_entry(this, struct dir_inode_entry, list);
+	list_for_each_entry(entry, head, list)
 		if (unlikely(entry->inode == inode))
 			return -EEXIST;
-	}
+
 	list_add_tail(&new->list, head);
 	stat_inc_dirty_dir(sbi);
 	return 0;
@@ -618,7 +611,8 @@
 void remove_dirty_dir_inode(struct inode *inode)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
-	struct list_head *this, *head;
+	struct list_head *head;
+	struct dir_inode_entry *entry;
 
 	if (!S_ISDIR(inode->i_mode))
 		return;
@@ -630,9 +624,7 @@
 	}
 
 	head = &sbi->dir_inode_list;
-	list_for_each(this, head) {
-		struct dir_inode_entry *entry;
-		entry = list_entry(this, struct dir_inode_entry, list);
+	list_for_each_entry(entry, head, list) {
 		if (entry->inode == inode) {
 			list_del(&entry->list);
 			stat_dec_dirty_dir(sbi);
@@ -654,15 +646,14 @@
 struct inode *check_dirty_dir_inode(struct f2fs_sb_info *sbi, nid_t ino)
 {
 
-	struct list_head *this, *head;
+	struct list_head *head;
 	struct inode *inode = NULL;
+	struct dir_inode_entry *entry;
 
 	spin_lock(&sbi->dir_inode_lock);
 
 	head = &sbi->dir_inode_list;
-	list_for_each(this, head) {
-		struct dir_inode_entry *entry;
-		entry = list_entry(this, struct dir_inode_entry, list);
+	list_for_each_entry(entry, head, list) {
 		if (entry->inode->i_ino == ino) {
 			inode = entry->inode;
 			break;
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 4b27e36..a161e95 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1451,7 +1451,6 @@
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct free_nid *i = NULL;
-	struct list_head *this;
 retry:
 	if (unlikely(sbi->total_valid_node_count + 1 >= nm_i->max_nid))
 		return false;
@@ -1461,11 +1460,9 @@
 	/* We should not use stale free nids created by build_free_nids */
 	if (nm_i->fcnt && !on_build_free_nids(nm_i)) {
 		f2fs_bug_on(list_empty(&nm_i->free_nid_list));
-		list_for_each(this, &nm_i->free_nid_list) {
-			i = list_entry(this, struct free_nid, list);
+		list_for_each_entry(i, &nm_i->free_nid_list, list)
 			if (i->state == NID_NEW)
 				break;
-		}
 
 		f2fs_bug_on(i->state != NID_NEW);
 		*nid = i->nid;
@@ -1780,7 +1777,7 @@
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
 	struct f2fs_summary_block *sum = curseg->sum_blk;
-	struct list_head *cur, *n;
+	struct nat_entry *ne, *cur;
 	struct page *page = NULL;
 	struct f2fs_nat_block *nat_blk = NULL;
 	nid_t start_nid = 0, end_nid = 0;
@@ -1792,18 +1789,17 @@
 		mutex_lock(&curseg->curseg_mutex);
 
 	/* 1) flush dirty nat caches */
-	list_for_each_safe(cur, n, &nm_i->dirty_nat_entries) {
-		struct nat_entry *ne;
+	list_for_each_entry_safe(ne, cur, &nm_i->dirty_nat_entries, list) {
 		nid_t nid;
 		struct f2fs_nat_entry raw_ne;
 		int offset = -1;
 		block_t new_blkaddr;
 
-		ne = list_entry(cur, struct nat_entry, list);
-		nid = nat_get_nid(ne);
-
 		if (nat_get_blkaddr(ne) == NEW_ADDR)
 			continue;
+
+		nid = nat_get_nid(ne);
+
 		if (flushed)
 			goto to_nat_page;
 
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index bbef4ed..b1ae89f 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -27,14 +27,12 @@
 static struct fsync_inode_entry *get_fsync_inode(struct list_head *head,
 								nid_t ino)
 {
-	struct list_head *this;
 	struct fsync_inode_entry *entry;
 
-	list_for_each(this, head) {
-		entry = list_entry(this, struct fsync_inode_entry, list);
+	list_for_each_entry(entry, head, list)
 		if (entry->inode->i_ino == ino)
 			return entry;
-	}
+
 	return NULL;
 }
 
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 570ab9a..cb49e639 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -340,8 +340,7 @@
 void clear_prefree_segments(struct f2fs_sb_info *sbi)
 {
 	struct list_head *head = &(SM_I(sbi)->discard_list);
-	struct list_head *this, *next;
-	struct discard_entry *entry;
+	struct discard_entry *entry, *this;
 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
 	unsigned int total_segs = TOTAL_SEGS(sbi);
@@ -370,8 +369,7 @@
 	mutex_unlock(&dirty_i->seglist_lock);
 
 	/* send small discards */
-	list_for_each_safe(this, next, head) {
-		entry = list_entry(this, struct discard_entry, list);
+	list_for_each_entry_safe(entry, this, head, list) {
 		f2fs_issue_discard(sbi, entry->blkaddr, entry->len);
 		list_del(&entry->list);
 		SM_I(sbi)->nr_discards -= entry->len;