From f3feb79eecb553d7f4475bccadddf7e6922ea5ca 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() BugLink: https://bugs.launchpad.net/bugs/2089884 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 Signed-off-by: Koichiro Den Signed-off-by: Roxana Nicolescu --- 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 2f53a72de219..0b5871035baf 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -412,6 +412,7 @@ 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); @@ -431,8 +432,10 @@ 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; @@ -462,7 +465,7 @@ 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,