f2fs: introduce function read_raw_super_block()

Introduce function read_raw_super_block() to hide reading raw super block and
the retry routine if the first sb is invalid.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 3b786c8..692f35f 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -746,30 +746,47 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
                atomic_set(&sbi->nr_pages[i], 0);
 }
 
-static int validate_superblock(struct super_block *sb,
-               struct f2fs_super_block **raw_super,
-               struct buffer_head **raw_super_buf, sector_t block)
+/*
+ * Read f2fs raw super block.
+ * Because we have two copies of super block, so read the first one at first,
+ * if the first one is invalid, move to read the second one.
+ */
+static int read_raw_super_block(struct super_block *sb,
+                       struct f2fs_super_block **raw_super,
+                       struct buffer_head **raw_super_buf)
 {
-       const char *super = (block == 0 ? "first" : "second");
+       int block = 0;
 
-       /* read f2fs raw super block */
+retry:
        *raw_super_buf = sb_bread(sb, block);
        if (!*raw_super_buf) {
-               f2fs_msg(sb, KERN_ERR, "unable to read %s superblock",
-                               super);
-               return -EIO;
+               f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
+                               block + 1);
+               if (block == 0) {
+                       block++;
+                       goto retry;
+               } else {
+                       return -EIO;
+               }
        }
 
        *raw_super = (struct f2fs_super_block *)
                ((char *)(*raw_super_buf)->b_data + F2FS_SUPER_OFFSET);
 
        /* sanity checking of raw super */
-       if (!sanity_check_raw_super(sb, *raw_super))
-               return 0;
+       if (sanity_check_raw_super(sb, *raw_super)) {
+               brelse(*raw_super_buf);
+               f2fs_msg(sb, KERN_ERR, "Can't find a valid F2FS filesystem "
+                               "in %dth superblock", block + 1);
+               if(block == 0) {
+                       block++;
+                       goto retry;
+               } else {
+                       return -EINVAL;
+               }
+       }
 
-       f2fs_msg(sb, KERN_ERR, "Can't find a valid F2FS filesystem "
-                               "in %s superblock", super);
-       return -EINVAL;
+       return 0;
 }
 
 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
@@ -791,14 +808,10 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
                goto free_sbi;
        }
 
-       err = validate_superblock(sb, &raw_super, &raw_super_buf, 0);
-       if (err) {
-               brelse(raw_super_buf);
-               /* check secondary superblock when primary failed */
-               err = validate_superblock(sb, &raw_super, &raw_super_buf, 1);
-               if (err)
-                       goto free_sb_buf;
-       }
+       err = read_raw_super_block(sb, &raw_super, &raw_super_buf);
+       if (err)
+               goto free_sbi;
+
        sb->s_fs_info = sbi;
        /* init some FS parameters */
        sbi->active_logs = NR_CURSEG_TYPE;