Re: [PATCH V2] f2fs: introduce free nid bitmap

[Jaegeuk Kim]

On 02/25, Chao Yu wrote:
> Hi Jaegeuk,
> 
> I added below diff code into this patch in order to fix incorrectly nid status
> updating to reduce large latency of generic/251 in fstest, could you help to
> review code below?

Understand the problem, and how about this?

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 52db02396878..83b305689913 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1765,7 +1765,7 @@ static void __remove_nid_from_list(struct f2fs_sb_info *sbi,
 		radix_tree_delete(&nm_i->free_nid_root, i->nid);
 }
 
-static int add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
+static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct free_nid *i;
@@ -1774,14 +1774,14 @@ static int add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
 
 	/* 0 nid should not be used */
 	if (unlikely(nid == 0))
-		return 0;
+		return false;
 
 	if (build) {
 		/* do not add allocated nids */
 		ne = __lookup_nat_cache(nm_i, nid);
 		if (ne && (!get_nat_flag(ne, IS_CHECKPOINTED) ||
 				nat_get_blkaddr(ne) != NULL_ADDR))
-			return 0;
+			return false;
 	}
 
 	i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
@@ -1790,7 +1790,7 @@ static int add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
 
 	if (radix_tree_preload(GFP_NOFS)) {
 		kmem_cache_free(free_nid_slab, i);
-		return 0;
+		return false;
 	}
 
 	spin_lock(&nm_i->nid_list_lock);
@@ -1799,9 +1799,9 @@ static int add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
 	radix_tree_preload_end();
 	if (err) {
 		kmem_cache_free(free_nid_slab, i);
-		return 0;
+		return false;
 	}
-	return 1;
+	return true;
 }
 
 static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
@@ -1851,6 +1851,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
 	i = start_nid % NAT_ENTRY_PER_BLOCK;
 
 	for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
+		bool freed = false;
 
 		if (unlikely(start_nid >= nm_i->max_nid))
 			break;
@@ -1858,8 +1859,8 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
 		blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
 		f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
 		if (blk_addr == NULL_ADDR)
-			add_free_nid(sbi, start_nid, true);
-		update_free_nid_bitmap(sbi, start_nid, blk_addr == NULL_ADDR);
+			freed = add_free_nid(sbi, start_nid, true);
+		update_free_nid_bitmap(sbi, start_nid, freed);
 	}
 }
 
-- 
2.11.0