From 7a6443e1dad70281f99f0bd394d7fd342481a632 Mon Sep 17 00:00:00 2001 From: "Luis Henriques (SUSE)" Date: Wed, 24 Jul 2024 17:11:17 +0100 Subject: [PATCH] ext4: fix incorrect tid assumption in jbd2_journal_shrink_checkpoint_list() Function jbd2_journal_shrink_checkpoint_list() assumes that '0' is not a valid value for transaction IDs, which is incorrect. Don't assume that and use two extra boolean variables to control the loop iterations and keep track of the first and last tid. Signed-off-by: Luis Henriques (SUSE) Reviewed-by: Jan Kara Link: https://patch.msgid.link/20240724161119.13448-4-luis.henriques@linux.dev Signed-off-by: Theodore Ts'o Cc: stable@kernel.org --- fs/jbd2/checkpoint.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index bd34083d5fa2..b3971e91e8eb 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -413,6 +413,7 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, tid_t tid = 0; unsigned long nr_freed = 0; unsigned long freed; + bool first_set = false; again: spin_lock(&journal->j_list_lock); @@ -432,8 +433,10 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, else transaction = journal->j_checkpoint_transactions; - if (!first_tid) + if (!first_set) { first_tid = transaction->t_tid; + first_set = true; + } last_transaction = journal->j_checkpoint_transactions->t_cpprev; next_transaction = transaction; last_tid = last_transaction->t_tid; @@ -463,7 +466,7 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, spin_unlock(&journal->j_list_lock); cond_resched(); - if (*nr_to_scan && next_tid) + if (*nr_to_scan && journal->j_shrink_transaction) goto again; out: trace_jbd2_shrink_checkpoint_list(journal, first_tid, tid, last_tid,