f2fs: introduce f2fs_kmem_cache_alloc to hide the unfailed, kmem cache allocation

Introduce the unfailed version of kmem_cache_alloc named f2fs_kmem_cache_alloc
to hide the retry routine and make the code a bit cleaner.

v2:
   Fix the wrong use of 'retry' tag pointed out by Gao feng.
   Use more neat code to remove redundant tag suggested by Haicheng Li.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/checkpoint.c

@@ -226,12 +226,8 @@ void add_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
 			break;
 		orphan = NULL;
 	}
-retry:
-	new = kmem_cache_alloc(orphan_entry_slab, GFP_ATOMIC);
-	if (!new) {
-		cond_resched();
-		goto retry;
-	}
+
+	new = f2fs_kmem_cache_alloc(orphan_entry_slab, GFP_ATOMIC);
 	new->ino = ino;
 
 	/* add new_oentry into list which is sorted by inode number */
@@ -484,12 +480,8 @@ void set_dirty_dir_page(struct inode *inode, struct page *page)
 
 	if (!S_ISDIR(inode->i_mode))
 		return;
-retry:
-	new = kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
-	if (!new) {
-		cond_resched();
-		goto retry;
-	}
+
+	new = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
 	new->inode = inode;
 	INIT_LIST_HEAD(&new->list);
 
@@ -506,13 +498,9 @@ void set_dirty_dir_page(struct inode *inode, struct page *page)
 void add_dirty_dir_inode(struct inode *inode)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
-	struct dir_inode_entry *new;
-retry:
-	new = kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
-	if (!new) {
-		cond_resched();
-		goto retry;
-	}
+	struct dir_inode_entry *new =
+			f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
+
 	new->inode = inode;
 	INIT_LIST_HEAD(&new->list);
 

fs/f2fs/f2fs.h

@@ -18,6 +18,7 @@
 #include <linux/crc32.h>
 #include <linux/magic.h>
 #include <linux/kobject.h>
+#include <linux/sched.h>
 
 /*
  * For mount options
@@ -787,6 +788,20 @@ static inline struct kmem_cache *f2fs_kmem_cache_create(const char *name,
 	return kmem_cache_create(name, size, 0, SLAB_RECLAIM_ACCOUNT, ctor);
 }
 
+static inline void *f2fs_kmem_cache_alloc(struct kmem_cache *cachep,
+						gfp_t flags)
+{
+	void *entry;
+retry:
+	entry = kmem_cache_alloc(cachep, flags);
+	if (!entry) {
+		cond_resched();
+		goto retry;
+	}
+
+	return entry;
+}
+
 #define RAW_IS_INODE(p)	((p)->footer.nid == (p)->footer.ino)
 
 static inline bool IS_INODE(struct page *page)

fs/f2fs/gc.c

@@ -361,12 +361,8 @@ static void add_gc_inode(struct inode *inode, struct list_head *ilist)
 		iput(inode);
 		return;
 	}
-repeat:
-	new_ie = kmem_cache_alloc(winode_slab, GFP_NOFS);
-	if (!new_ie) {
-		cond_resched();
-		goto repeat;
-	}
+
+	new_ie = f2fs_kmem_cache_alloc(winode_slab, GFP_NOFS);
 	new_ie->inode = inode;
 	list_add_tail(&new_ie->list, ilist);
 }

fs/f2fs/node.c

@@ -1296,23 +1296,18 @@ static int add_free_nid(struct f2fs_nm_info *nm_i, nid_t nid, bool build)
 	if (nid == 0)
 		return 0;
 
-	if (!build)
-		goto retry;
-
-	/* do not add allocated nids */
-	read_lock(&nm_i->nat_tree_lock);
-	ne = __lookup_nat_cache(nm_i, nid);
-	if (ne && nat_get_blkaddr(ne) != NULL_ADDR)
-		allocated = true;
-	read_unlock(&nm_i->nat_tree_lock);
-	if (allocated)
-		return 0;
-retry:
-	i = kmem_cache_alloc(free_nid_slab, GFP_NOFS);
-	if (!i) {
-		cond_resched();
-		goto retry;
+	if (build) {
+		/* do not add allocated nids */
+		read_lock(&nm_i->nat_tree_lock);
+		ne = __lookup_nat_cache(nm_i, nid);
+		if (ne && nat_get_blkaddr(ne) != NULL_ADDR)
+			allocated = true;
+		read_unlock(&nm_i->nat_tree_lock);
+		if (allocated)
+			return 0;
 	}
+
+	i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
 	i->nid = nid;
 	i->state = NID_NEW;