在 2022/12/21 18:13, Jan Kara 写道:
On Tue 20-12-22 23:05:51, Zhihao Cheng wrote:
From: zhanchengbin <zhanchengbin1@xxxxxxxxxx>
Following process will make data lost and could lead to a filesystem
corrupted problem:
1. jh(bh) is inserted into T1->t_checkpoint_list, bh is dirty, and
jh->b_transaction = NULL
2. T1 is added into journal->j_checkpoint_transactions.
3. Get bh prepare to write while doing checkpoing:
PA PB
do_get_write_access jbd2_log_do_checkpoint
spin_lock(&jh->b_state_lock)
if (buffer_dirty(bh))
clear_buffer_dirty(bh) // clear buffer dirty
set_buffer_jbddirty(bh)
transaction =
journal->j_checkpoint_transactions
jh = transaction->t_checkpoint_list
if (!buffer_dirty(bh))
__jbd2_journal_remove_checkpoint(jh)
// bh won't be flushed
jbd2_cleanup_journal_tail
__jbd2_journal_file_buffer(jh, transaction, BJ_Reserved)
4. Aborting journal/Power-cut before writing latest bh on journal area.
[...]
fs/jbd2/transaction.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
Good catch! Did you find it by code inspection or were you able to actually
trigger this problem?
By code inspection.
Reproducer: https://bugzilla.kernel.org/show_bug.cgi?id=216898
