On 11/15/19 3:52 PM, Jan Kara wrote:
The helper jbd2_handle_buffer_credits() doesn't correctly handle reserved
handles which can lead to crashes. Fix it getting of journal pointer to
work for reserved handles as well.
Fixes: a9a8344ee171 ("ext4, jbd2: Provide accessor function for handle credits")
Reported-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Thanks Jan,
Yes, this also fixes the problem for me with dioread_nolock on ppc64
machine.
You may add -
Tested-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>
---
include/linux/jbd2.h | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 3115eeb44039..a23a3528e07a 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1648,10 +1648,14 @@ static inline tid_t jbd2_get_latest_transaction(journal_t *journal)
return tid;
}
-
static inline int jbd2_handle_buffer_credits(handle_t *handle)
{
- journal_t *journal = handle->h_transaction->t_journal;
+ journal_t *journal;
+
+ if (!handle->h_reserved)
+ journal = handle->h_transaction->t_journal;
+ else
+ journal = handle->h_journal;
return handle->h_total_credits -
DIV_ROUND_UP(handle->h_revoke_credits_requested,
