Message ID | 20100908020429.GA24635@redhat.com |
---|---|
State | Not Applicable |
Delegated to: | David Miller |
Headers | show |
On 09/08/2010 04:04 AM, Mike Snitzer wrote: > Rename __clone_and_map_flush to __clone_and_map_empty_flush for added > clarity. > > Simplify logic associated with REQ_FLUSH conditionals. > > Introduce a BUG_ON() and add a few more helpful comments to the code > so that it is clear that all flushes are empty. > > Cleanup __split_and_process_bio() so that an empty flush isn't processed > by a 'sector_count' focused while loop. > > Signed-off-by: Mike Snitzer <snitzer@redhat.com> > --- > drivers/md/dm.c | 34 +++++++++++++++------------------- > 1 files changed, 15 insertions(+), 19 deletions(-) > > Tejun, please feel free to fold this patch into (or insert after) > 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch > > v2: Simplify logic associated with REQ_FLUSH conditionals > > diff --git a/drivers/md/dm.c b/drivers/md/dm.c > index cd2f7e7..f934e98 100644 > --- a/drivers/md/dm.c > +++ b/drivers/md/dm.c > @@ -621,16 +621,17 @@ static void dec_pending(struct dm_io *io, int error) > if (io_error == DM_ENDIO_REQUEUE) > return; > > - if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) { > - trace_block_bio_complete(md->queue, bio); > - bio_endio(bio, io_error); > - } else { > + if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) { > /* > * Preflush done for flush with data, reissue > * without REQ_FLUSH. > */ > bio->bi_rw &= ~REQ_FLUSH; > queue_io(md, bio); > + } else { > + /* done with normal IO or empty flush */ > + trace_block_bio_complete(md->queue, bio); > + bio_endio(bio, io_error); > } > } > } > @@ -1132,16 +1133,15 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti, > __issue_target_request(ci, ti, request_nr, len); > } > > -static int __clone_and_map_flush(struct clone_info *ci) > +static int __clone_and_map_empty_flush(struct clone_info *ci) > { > unsigned target_nr = 0; > struct dm_target *ti; > > + BUG_ON(bio_has_data(ci->bio)); > while ((ti = dm_table_get_target(ci->map, target_nr++))) > __issue_target_requests(ci, ti, ti->num_flush_requests, 0); > > - ci->sector_count = 0; > - > return 0; > } > > @@ -1282,7 +1282,6 @@ static int __clone_and_map(struct clone_info *ci) > */ > static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) > { > - bool is_flush = bio->bi_rw & REQ_FLUSH; > struct clone_info ci; > int error = 0; > > @@ -1302,20 +1301,17 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) > ci.sector = bio->bi_sector; > ci.idx = bio->bi_idx; > > - if (!is_flush) { > + start_io_acct(ci.io); > + if (bio->bi_rw & REQ_FLUSH) { > + ci.bio = &ci.md->flush_bio; > + ci.sector_count = 0; > + error = __clone_and_map_empty_flush(&ci); > + /* dec_pending submits any data associated with flush */ > + } else { > ci.bio = bio; > ci.sector_count = bio_sectors(bio); > - } else { > - ci.bio = &ci.md->flush_bio; > - ci.sector_count = 1; > - } > - > - start_io_acct(ci.io); > - while (ci.sector_count && !error) { > - if (!is_flush) > + while (ci.sector_count && !error) > error = __clone_and_map(&ci); > - else > - error = __clone_and_map_flush(&ci); > } > > /* drop the extra reference count */
On 09/08/2010 04:04 AM, Mike Snitzer wrote: > Rename __clone_and_map_flush to __clone_and_map_empty_flush for added > clarity. > > Simplify logic associated with REQ_FLUSH conditionals. > > Introduce a BUG_ON() and add a few more helpful comments to the code > so that it is clear that all flushes are empty. > > Cleanup __split_and_process_bio() so that an empty flush isn't processed > by a 'sector_count' focused while loop. > > Signed-off-by: Mike Snitzer <snitzer@redhat.com> > --- > drivers/md/dm.c | 34 +++++++++++++++------------------- > 1 files changed, 15 insertions(+), 19 deletions(-) > > Tejun, please feel free to fold this patch into (or insert after) > 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch I added it after 26 and updated flush-fua branch accordingly. Thank you.
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index cd2f7e7..f934e98 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -621,16 +621,17 @@ static void dec_pending(struct dm_io *io, int error) if (io_error == DM_ENDIO_REQUEUE) return; - if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) { - trace_block_bio_complete(md->queue, bio); - bio_endio(bio, io_error); - } else { + if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) { /* * Preflush done for flush with data, reissue * without REQ_FLUSH. */ bio->bi_rw &= ~REQ_FLUSH; queue_io(md, bio); + } else { + /* done with normal IO or empty flush */ + trace_block_bio_complete(md->queue, bio); + bio_endio(bio, io_error); } } } @@ -1132,16 +1133,15 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti, __issue_target_request(ci, ti, request_nr, len); } -static int __clone_and_map_flush(struct clone_info *ci) +static int __clone_and_map_empty_flush(struct clone_info *ci) { unsigned target_nr = 0; struct dm_target *ti; + BUG_ON(bio_has_data(ci->bio)); while ((ti = dm_table_get_target(ci->map, target_nr++))) __issue_target_requests(ci, ti, ti->num_flush_requests, 0); - ci->sector_count = 0; - return 0; } @@ -1282,7 +1282,6 @@ static int __clone_and_map(struct clone_info *ci) */ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) { - bool is_flush = bio->bi_rw & REQ_FLUSH; struct clone_info ci; int error = 0; @@ -1302,20 +1301,17 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) ci.sector = bio->bi_sector; ci.idx = bio->bi_idx; - if (!is_flush) { + start_io_acct(ci.io); + if (bio->bi_rw & REQ_FLUSH) { + ci.bio = &ci.md->flush_bio; + ci.sector_count = 0; + error = __clone_and_map_empty_flush(&ci); + /* dec_pending submits any data associated with flush */ + } else { ci.bio = bio; ci.sector_count = bio_sectors(bio); - } else { - ci.bio = &ci.md->flush_bio; - ci.sector_count = 1; - } - - start_io_acct(ci.io); - while (ci.sector_count && !error) { - if (!is_flush) + while (ci.sector_count && !error) error = __clone_and_map(&ci); - else - error = __clone_and_map_flush(&ci); } /* drop the extra reference count */
Rename __clone_and_map_flush to __clone_and_map_empty_flush for added clarity. Simplify logic associated with REQ_FLUSH conditionals. Introduce a BUG_ON() and add a few more helpful comments to the code so that it is clear that all flushes are empty. Cleanup __split_and_process_bio() so that an empty flush isn't processed by a 'sector_count' focused while loop. Signed-off-by: Mike Snitzer <snitzer@redhat.com> --- drivers/md/dm.c | 34 +++++++++++++++------------------- 1 files changed, 15 insertions(+), 19 deletions(-) Tejun, please feel free to fold this patch into (or insert after) 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch v2: Simplify logic associated with REQ_FLUSH conditionals -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html