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From: Kemeng Shi <shikemeng@huaweicloud.com>
To: tytso@mit.edu,
	jack@suse.com
Cc: linux-ext4@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 7/9] jbd2: remove dead equality check of j_commit_[sequence/request] in kjournald2
Date: Mon,  6 May 2024 22:17:59 +0800
Message-Id: <20240506141801.1165315-8-shikemeng@huaweicloud.com>
In-Reply-To: <20240506141801.1165315-1-shikemeng@huaweicloud.com>
References: <20240506141801.1165315-1-shikemeng@huaweicloud.com>
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In kjournald2, two equality checks of j_commit_[sequence/request] are
under the same j_state_lock. As j_commit_[sequence/request] are updated
concurrently with j_state_lock held during runtime, the second check is
unnecessary.
The j_commit_sequence is only updated concurrently in
jbd2_journal_commit_transaction with j_state_lock held.
The j_commit_request is only updated concurrently in
__jbd2_log_start_commit with j_state_lock held.
Also see comment in struct journal_s about lock rule of j_commit_sequence
and j_commit_request.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
 fs/jbd2/journal.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 01e33b643e4d..e8f592fbd6e1 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -224,8 +224,6 @@ static int kjournald2(void *arg)
 
 		prepare_to_wait(&journal->j_wait_commit, &wait,
 				TASK_INTERRUPTIBLE);
-		if (journal->j_commit_sequence != journal->j_commit_request)
-			should_sleep = 0;
 		transaction = journal->j_running_transaction;
 		if (transaction && time_after_eq(jiffies,
 						transaction->t_expires))
-- 
2.30.0