jbd2: Fix checkpoint list cleanup

PATCH Applied Jan Kara 2 participants 2 messages Oct 5, 2015 – Oct 18, 2015 Journalling layer for block devices (JBD2)

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Jan Kara

author maintainer

2015-10-05 13:59 UTC #0 lore raw

PATCH 1/1 jbd2: Fix checkpoint list cleanup

Unlike comments and expectation of callers journal_clean_one_cp_list() returned 1 not only if it freed the transaction but also if it freed some buffers in the transaction. That could make __jbd2_journal_clean_checkpoint_list() skip processing t_checkpoint_io_list and continue with processing the next transaction. This is mostly a cosmetic issue since the only result is we can sometimes free less memory than we could. But it's still worth fixing. Fix journal_clean_one_cp_list() to return 1 only if the transaction was really freed.

Fixes 50849db32a9f529235a84bcc84a6b8e631b1d0ec

Signed-off-by Jan Kara <[email protected]>

---
 fs/jbd2/checkpoint.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

fs/jbd2/checkpoint.c +3 -5

index 8c44654ce274..684996c8a3a4 100644
@@ -427,7 +427,6 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
 	struct journal_head *last_jh;
 	struct journal_head *next_jh = jh;
 	int ret;
-	int freed = 0;
 
 	if (!jh)
 		return 0;

@@ -441,10 +440,9 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
 		else
 			ret = __jbd2_journal_remove_checkpoint(jh) + 1;
 		if (!ret)
-			return freed;
+			return 0;
 		if (ret == 2)
 			return 1;
-		freed = 1;
 		/*
 		 * This function only frees up some memory
 		 * if possible so we dont have an obligation

@@ -452,10 +450,10 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
 		 * requested:
 		 */
 		if (need_resched())
-			return freed;
+			return 0;
 	} while (jh != last_jh);
 
-	return freed;
+	return 0;
 }
 
 /*

Signature · 1 line

2.1.4

Theodore Ts'o

maintainer Applied

2015-10-18 02:42 UTC #1 lore raw

Quoted 10 lines · Jan Kara

Unlike comments and expectation of callers journal_clean_one_cp_list() returned 1 not only if it freed the transaction but also if it freed some buffers in the transaction. That could make __jbd2_journal_clean_checkpoint_list() skip processing t_checkpoint_io_list and continue with processing the next transaction. This is mostly a cosmetic issue since the only result is we can sometimes free less memory than we could. But it's still worth fixing. Fix journal_clean_one_cp_list() to return 1 only if the transaction was really freed.

Quoted 2 lines

Fixes 50849db32a9f529235a84bcc84a6b8e631b1d0ec
Signed-off-by Jan Kara <[email protected]>

Applied, thanks.

- Ted