SET_KEY_DIRTY sets it to false when bi_status is not 0.
We do the write if KEY_DIRTY is true, else it is skipped.
Mike
On Wed, Sep 27, 2017 at 1:22 AM, Coly Li <i@xxxxxxx> wrote:
> On 2017/9/27 上午3:24, Michael Lyle wrote:
>> If an IO operation fails, and we didn't successfully read data from the
>> cache, don't writeback invalid/partial data to the backing disk.
>>
>> Signed-off-by: Michael Lyle <mlyle@xxxxxxxx>
>> ---
>> drivers/md/bcache/writeback.c | 19 +++++++++++++------
>> 1 file changed, 13 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
>> index e663ca082183..eea49bf36401 100644
>> --- a/drivers/md/bcache/writeback.c
>> +++ b/drivers/md/bcache/writeback.c
>> @@ -179,13 +179,20 @@ static void write_dirty(struct closure *cl)
>> struct dirty_io *io = container_of(cl, struct dirty_io, cl);
>> struct keybuf_key *w = io->bio.bi_private;
>>
>> - dirty_init(w);
>> - bio_set_op_attrs(&io->bio, REQ_OP_WRITE, 0);
>> - io->bio.bi_iter.bi_sector = KEY_START(&w->key);
>> - bio_set_dev(&io->bio, io->dc->bdev);
>> - io->bio.bi_end_io = dirty_endio;
>> + /* IO errors are signalled using the dirty bit on the key.
>> + * If we failed to read, we should not attempt to write to the
>> + * backing device. Instead, immediately go to write_dirty_finish
>> + * to clean up.
>> + */
>> + if (KEY_DIRTY(&w->key)) {
> Maybe it should be "if (!KEY_DIRTY(&w->key))" ? In dirty_endio(),
> SET_KEY_DIRTY() is called only when bio->bi_status is not 0.
>
>
>> + dirty_init(w);
>> + bio_set_op_attrs(&io->bio, REQ_OP_WRITE, 0);
>> + io->bio.bi_iter.bi_sector = KEY_START(&w->key);
>> + bio_set_dev(&io->bio, io->dc->bdev);
>> + io->bio.bi_end_io = dirty_endio;
>>
>> - closure_bio_submit(&io->bio, cl);
>> + closure_bio_submit(&io->bio, cl);
>> + }
>>
>> continue_at(cl, write_dirty_finish, io->dc->writeback_write_wq);
>> }
>>
>
>
> --
> Coly Li
--
To unsubscribe from this list: send the line "unsubscribe linux-bcache" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
