--- zzzz-none-000/linux-3.10.107/fs/ext4/mmp.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/ext4/mmp.c	2021-02-04 17:41:59.000000000 +0000
@@ -18,19 +18,17 @@
 	return cpu_to_le32(csum);
 }
 
-int ext4_mmp_csum_verify(struct super_block *sb, struct mmp_struct *mmp)
+static int ext4_mmp_csum_verify(struct super_block *sb, struct mmp_struct *mmp)
 {
-	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
-				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+	if (!ext4_has_metadata_csum(sb))
 		return 1;
 
 	return mmp->mmp_checksum == ext4_mmp_csum(sb, mmp);
 }
 
-void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp)
+static void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp)
 {
-	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
-				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+	if (!ext4_has_metadata_csum(sb))
 		return;
 
 	mmp->mmp_checksum = ext4_mmp_csum(sb, mmp);
@@ -71,6 +69,7 @@
 			  ext4_fsblk_t mmp_block)
 {
 	struct mmp_struct *mmp;
+	int ret;
 
 	if (*bh)
 		clear_buffer_uptodate(*bh);
@@ -78,33 +77,38 @@
 	/* This would be sb_bread(sb, mmp_block), except we need to be sure
 	 * that the MD RAID device cache has been bypassed, and that the read
 	 * is not blocked in the elevator. */
-	if (!*bh)
+	if (!*bh) {
 		*bh = sb_getblk(sb, mmp_block);
-	if (!*bh)
-		return -ENOMEM;
-	if (*bh) {
-		get_bh(*bh);
-		lock_buffer(*bh);
-		(*bh)->b_end_io = end_buffer_read_sync;
-		submit_bh(READ_SYNC | REQ_META | REQ_PRIO, *bh);
-		wait_on_buffer(*bh);
-		if (!buffer_uptodate(*bh)) {
-			brelse(*bh);
-			*bh = NULL;
+		if (!*bh) {
+			ret = -ENOMEM;
+			goto warn_exit;
 		}
 	}
-	if (unlikely(!*bh)) {
-		ext4_warning(sb, "Error while reading MMP block %llu",
-			     mmp_block);
-		return -EIO;
+
+	get_bh(*bh);
+	lock_buffer(*bh);
+	(*bh)->b_end_io = end_buffer_read_sync;
+	submit_bh(READ_SYNC | REQ_META | REQ_PRIO, *bh);
+	wait_on_buffer(*bh);
+	if (!buffer_uptodate(*bh)) {
+		brelse(*bh);
+		*bh = NULL;
+		ret = -EIO;
+		goto warn_exit;
 	}
 
 	mmp = (struct mmp_struct *)((*bh)->b_data);
-	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC ||
-	    !ext4_mmp_csum_verify(sb, mmp))
-		return -EINVAL;
-
-	return 0;
+	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC)
+		ret = -EFSCORRUPTED;
+	else if (!ext4_mmp_csum_verify(sb, mmp))
+		ret = -EFSBADCRC;
+	else
+		return 0;
+
+warn_exit:
+	ext4_warning(sb, "Error %d while reading MMP block %llu",
+		     ret, mmp_block);
+	return ret;
 }
 
 /*
@@ -113,7 +117,7 @@
 void __dump_mmp_msg(struct super_block *sb, struct mmp_struct *mmp,
 		    const char *function, unsigned int line, const char *msg)
 {
-	__ext4_warning(sb, function, line, msg);
+	__ext4_warning(sb, function, line, "%s", msg);
 	__ext4_warning(sb, function, line,
 		       "MMP failure info: last update time: %llu, last update "
 		       "node: %s, last update device: %s\n",
@@ -259,7 +263,7 @@
 	u32 new_seq;
 
 	do {
-		get_random_bytes(&new_seq, sizeof(u32));
+		new_seq = prandom_u32();
 	} while (new_seq > EXT4_MMP_SEQ_MAX);
 
 	return new_seq;