On Mon 17-02-20 19:27:06, zhangyi (F) wrote:
> Improve comments in jbd2_journal_commit_transaction() to describe why
> we don't need to clear the buffer_mapped bit for freeing file mapping
> buffers whose page mapping is NULL.
>
> Fixes: c96dceeabf76 ("jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer")
> Signed-off-by: zhangyi (F) <yi.zhang@xxxxxxxxxx>
> Suggested-by: Jan Kara <jack@xxxxxxx>
Thanks! You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/jbd2/commit.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
> index 27373f5792a4..e855d8260433 100644
> --- a/fs/jbd2/commit.c
> +++ b/fs/jbd2/commit.c
> @@ -997,9 +997,10 @@ void jbd2_journal_commit_transaction(journal_t *journal)
> * journalled data) we need to unmap buffer and clear
> * more bits. We also need to be careful about the check
> * because the data page mapping can get cleared under
> - * out hands, which alse need not to clear more bits
> - * because the page and buffers will be freed and can
> - * never be reused once we are done with them.
> + * our hands. Note that if mapping == NULL, we don't
> + * need to make buffer unmapped because the page is
> + * already detached from the mapping and buffers cannot
> + * get reused.
> */
> mapping = READ_ONCE(bh->b_page->mapping);
> if (mapping && !sb_is_blkdev_sb(mapping->host->i_sb)) {
> --
> 2.17.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
