[PATCH RESEND] f2fs: introduce function read_raw_super_block()

From: Gu Zheng
Date: Mon Oct 14 2013 - 06:53:03 EST


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@xxxxxxxxxxxxxx>
---
fs/f2fs/super.c | 54 +++++++++++++++++++++++++++++++++---------------------
1 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 3b786c8..5e913de 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -746,30 +746,46 @@ 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 +807,10 @@ 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;
--
1.7.7

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