f2fs: optimize scan_nat_page()

When nm_i->fcnt > 2 * MAX_FREE_NIDS, stop scanning other NAT entries.

Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
[Jaegeuk Kim: fix handling the return value of add_free_nid()]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 122200e..e42934e 100644 (file)
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1254,7 +1254,7 @@ static int add_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
        struct free_nid *i;
 
        if (nm_i->fcnt > 2 * MAX_FREE_NIDS)
-               return 0;
+               return -1;
 
        /* 0 nid should not be used */
        if (nid == 0)
@@ -1302,12 +1302,16 @@ static void scan_nat_page(struct f2fs_nm_info *nm_i,
        i = start_nid % NAT_ENTRY_PER_BLOCK;
 
        for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
+
                if (start_nid >= nm_i->max_nid)
                        break;
-               blk_addr  = le32_to_cpu(nat_blk->entries[i].block_addr);
+
+               blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
                BUG_ON(blk_addr == NEW_ADDR);
-               if (blk_addr == NULL_ADDR)
-                       add_free_nid(nm_i, start_nid);
+               if (blk_addr == NULL_ADDR) {
+                       if (add_free_nid(nm_i, start_nid) < 0)
+                               break;
+               }
        }
 }
 
@@ -1655,7 +1659,7 @@ flush_now:
                }
 
                if (nat_get_blkaddr(ne) == NULL_ADDR &&
-                                       !add_free_nid(NM_I(sbi), nid)) {
+                               add_free_nid(NM_I(sbi), nid) <= 0) {
                        write_lock(&nm_i->nat_tree_lock);
                        __del_from_nat_cache(nm_i, ne);
                        write_unlock(&nm_i->nat_tree_lock);