On Thu 10-01-19 14:06:38, zhangyi (F) wrote:
> The jh pointer may be used uninitialized in the two cases below and the
> compiler complain about it when enabling JBUFFER_TRACE macro, fix them.
>
> In file included from fs/jbd2/transaction.c:19:0:
> fs/jbd2/transaction.c: In function ‘jbd2_journal_get_undo_access’:
> ./include/linux/jbd2.h:1637:38: warning: ‘jh’ is used uninitialized in this function [-Wuninitialized]
> #define JBUFFER_TRACE(jh, info) do { printk("%s: %d\n", __func__, jh->b_jcount);} while (0)
> ^
> fs/jbd2/transaction.c:1219:23: note: ‘jh’ was declared here
> struct journal_head *jh;
> ^
> In file included from fs/jbd2/transaction.c:19:0:
> fs/jbd2/transaction.c: In function ‘jbd2_journal_dirty_metadata’:
> ./include/linux/jbd2.h:1637:38: warning: ‘jh’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> #define JBUFFER_TRACE(jh, info) do { printk("%s: %d\n", __func__, jh->b_jcount);} while (0)
> ^
> fs/jbd2/transaction.c:1332:23: note: ‘jh’ was declared here
> struct journal_head *jh;
> ^
>
> Signed-off-by: zhangyi (F) <yi.zhang@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> fs/jbd2/transaction.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
The patch looks good. Thanks! You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
>
> diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
> index c0b66a7..4b51177 100644
> --- a/fs/jbd2/transaction.c
> +++ b/fs/jbd2/transaction.c
> @@ -1219,11 +1219,12 @@ int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh)
> struct journal_head *jh;
> char *committed_data = NULL;
>
> - JBUFFER_TRACE(jh, "entry");
> if (jbd2_write_access_granted(handle, bh, true))
> return 0;
>
> jh = jbd2_journal_add_journal_head(bh);
> + JBUFFER_TRACE(jh, "entry");
> +
> /*
> * Do this first --- it can drop the journal lock, so we want to
> * make sure that obtaining the committed_data is done
> @@ -1334,15 +1335,17 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
>
> if (is_handle_aborted(handle))
> return -EROFS;
> - if (!buffer_jbd(bh)) {
> - ret = -EUCLEAN;
> - goto out;
> - }
> + if (!buffer_jbd(bh))
> + return -EUCLEAN;
> +
> /*
> * We don't grab jh reference here since the buffer must be part
> * of the running transaction.
> */
> jh = bh2jh(bh);
> + jbd_debug(5, "journal_head %p\n", jh);
> + JBUFFER_TRACE(jh, "entry");
> +
> /*
> * This and the following assertions are unreliable since we may see jh
> * in inconsistent state unless we grab bh_state lock. But this is
> @@ -1376,9 +1379,6 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
> }
>
> journal = transaction->t_journal;
> - jbd_debug(5, "journal_head %p\n", jh);
> - JBUFFER_TRACE(jh, "entry");
> -
> jbd_lock_bh_state(bh);
>
> if (jh->b_modified == 0) {
> --
> 2.7.4
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
