From 354835cea9eae2920033d0534d72ed15b8f26246 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() commit 7a6443e1dad70281f99f0bd394d7fd342481a632 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- 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 45e42df4c17c..ee4ee1d709d2 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -424,6 +424,7 @@ 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); @@ -443,8 +444,10 @@ again: 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; @@ -474,7 +477,7 @@ again: 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,