linux-kernel - [PATCH -next v3 1/5] ext4: init 'seq' with the value which set in 'ext4_multi_mount

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Date:   Tue, 19 Oct 2021 14:49:55 +0800
From:   Ye Bin <yebin10@...wei.com>
To:     <tytso@....edu>, <adilger.kernel@...ger.ca>,
        <linux-ext4@...r.kernel.org>
CC:     <linux-kernel@...r.kernel.org>, <jack@...e.cz>,
        Ye Bin <yebin10@...wei.com>
Subject: [PATCH -next v3 1/5] ext4: init 'seq' with the value which set in 'ext4_multi_mount_protect'

If two host have the same nodename, and seq start from 0, May cause the
detection mechanism to fail.
So init 'seq' with the value which set in 'ext4_multi_mount_protect' to
accelerate conflict detection.

Signed-off-by: Ye Bin <yebin10@...wei.com>
---
 fs/ext4/mmp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index cebea4270817..11627ff002d3 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -132,7 +132,7 @@ static int kmmpd(void *data)
 	struct buffer_head *bh = EXT4_SB(sb)->s_mmp_bh;
 	struct mmp_struct *mmp;
 	ext4_fsblk_t mmp_block;
-	u32 seq = 0;
+	u32 seq;
 	unsigned long failed_writes = 0;
 	int mmp_update_interval = le16_to_cpu(es->s_mmp_update_interval);
 	unsigned mmp_check_interval;
@@ -143,6 +143,7 @@ static int kmmpd(void *data)
 	mmp_block = le64_to_cpu(es->s_mmp_block);
 	mmp = (struct mmp_struct *)(bh->b_data);
 	mmp->mmp_time = cpu_to_le64(ktime_get_real_seconds());
+	seq = le32_to_cpu(mmp->mmp_seq);
 	/*
 	 * Start with the higher mmp_check_interval and reduce it if
 	 * the MMP block is being updated on time.
-- 
2.31.1