Patch "f2fs: slightly reorganize read_raw_super_block" has been added to the 4.5-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    f2fs: slightly reorganize read_raw_super_block

to the 4.5-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     f2fs-slightly-reorganize-read_raw_super_block.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 2b39e9072d79ab2525100413f3f7a0b8a3e15873 Mon Sep 17 00:00:00 2001
From: Shawn Lin <shawn.lin@rock-chips.com>
Date: Wed, 17 Feb 2016 08:59:01 +0800
Subject: f2fs: slightly reorganize read_raw_super_block

From: Shawn Lin <shawn.lin@rock-chips.com>

commit 2b39e9072d79ab2525100413f3f7a0b8a3e15873 upstream.

read_raw_super_block was introduced to help find the
first valid superblock. Commit da554e48caab ("f2fs:
recovering broken superblock during mount") changed the
behaviour to read both of them and check whether need
the recovery flag or not. So the comment before this
function isn't consistent with what it actually does.
Also, the origin code use two tags to round the err
cases, which isn't so readable. So this patch amend
the comment and slightly reorganize it.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/f2fs/super.c |   77 +++++++++++++++++++++++++++-----------------------------
 1 file changed, 38 insertions(+), 39 deletions(-)

--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1134,14 +1134,15 @@ static void init_sb_info(struct f2fs_sb_
 
 /*
  * 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.
+ * Because we have two copies of super block, so read both of them
+ * to get the first valid one. If any one of them is broken, we pass
+ * them recovery flag back to the caller.
  */
 static int read_raw_super_block(struct super_block *sb,
 			struct f2fs_super_block **raw_super,
 			int *valid_super_block, int *recovery)
 {
-	int block = 0;
+	int block;
 	struct buffer_head *bh;
 	struct f2fs_super_block *super, *buf;
 	int err = 0;
@@ -1149,50 +1150,48 @@ static int read_raw_super_block(struct s
 	super = kzalloc(sizeof(struct f2fs_super_block), GFP_KERNEL);
 	if (!super)
 		return -ENOMEM;
-retry:
-	bh = sb_bread(sb, block);
-	if (!bh) {
-		*recovery = 1;
-		f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
-				block + 1);
-		err = -EIO;
-		goto next;
-	}
 
-	buf = (struct f2fs_super_block *)(bh->b_data + F2FS_SUPER_OFFSET);
-
-	/* sanity checking of raw super */
-	if (sanity_check_raw_super(sb, buf)) {
+	for (block = 0; block < 2; block++) {
+		bh = sb_bread(sb, block);
+		if (!bh) {
+			f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
+				block + 1);
+			err = -EIO;
+			continue;
+		}
+
+		buf = (struct f2fs_super_block *)
+				(bh->b_data + F2FS_SUPER_OFFSET);
+
+		/* sanity checking of raw super */
+		if (sanity_check_raw_super(sb, buf)) {
+			f2fs_msg(sb, KERN_ERR,
+				"Can't find valid F2FS filesystem in %dth superblock",
+				block + 1);
+			err = -EINVAL;
+			brelse(bh);
+			continue;
+		}
+
+		if (!*raw_super) {
+			memcpy(super, buf, sizeof(*super));
+			*valid_super_block = block;
+			*raw_super = super;
+		}
 		brelse(bh);
-		*recovery = 1;
-		f2fs_msg(sb, KERN_ERR,
-			"Can't find valid F2FS filesystem in %dth superblock",
-								block + 1);
-		err = -EINVAL;
-		goto next;
-	}
-
-	if (!*raw_super) {
-		memcpy(super, buf, sizeof(*super));
-		*valid_super_block = block;
-		*raw_super = super;
 	}
-	brelse(bh);
 
-next:
-	/* check the validity of the second superblock */
-	if (block == 0) {
-		block++;
-		goto retry;
-	}
+	/* Fail to read any one of the superblocks*/
+	if (err < 0)
+		*recovery = 1;
 
 	/* No valid superblock */
-	if (!*raw_super) {
+	if (!*raw_super)
 		kfree(super);
-		return err;
-	}
+	else
+		err = 0;
 
-	return 0;
+	return err;
 }
 
 static int __f2fs_commit_super(struct f2fs_sb_info *sbi, int block)


Patches currently in stable-queue which might be from shawn.lin@rock-chips.com are

queue-4.5/f2fs-slightly-reorganize-read_raw_super_block.patch
queue-4.5/spi-rockchip-modify-dma-max-burst-to-1.patch