Recent commit c2247f3745 while fixing barriers for ordinary requests, accidentally smashed delay_fua optimization for io_direct by:
> + bio->bi_rw |= bw.cur->bi_rw & (REQ_FLUSH | REQ_FUA); The idea is the following: if at least one incoming bio is marked as FUA (it is actually equivalent to (rw & REQ_FUA) check), and eng_state == E_DATA_WBI, we can delay FUA until index update and implement it there by REQ_FLUSH. It is not clear if this optimization provides any benefits, but if we lived with it for long so far, let's keep it for now. The patch removes PLOOP_REQ_FORCE_FLUSH thoroughly because it's easier to use REQ_FLUSH bit in preq->req_rw instead. Signed-off-by: Maxim Patlasov <mpatla...@virtuozzo.com> --- drivers/block/ploop/io_direct.c | 15 ++++++--------- drivers/block/ploop/map.c | 25 ++++++++++++++++++------- include/linux/ploop/ploop.h | 1 - 3 files changed, 24 insertions(+), 17 deletions(-) diff --git a/drivers/block/ploop/io_direct.c b/drivers/block/ploop/io_direct.c index db82a61..1ea2008 100644 --- a/drivers/block/ploop/io_direct.c +++ b/drivers/block/ploop/io_direct.c @@ -92,23 +92,19 @@ dio_submit(struct ploop_io *io, struct ploop_request * preq, int preflush; int postfua = 0; int write = !!(rw & REQ_WRITE); + int delayed_fua = 0; trace_submit(preq); preflush = !!(rw & REQ_FLUSH); - if (test_and_clear_bit(PLOOP_REQ_FORCE_FLUSH, &preq->state)) - preflush = 1; - if (test_and_clear_bit(PLOOP_REQ_FORCE_FUA, &preq->state)) postfua = 1; - if (!postfua && ploop_req_delay_fua_possible(preq) && (rw & REQ_FUA)) { - + if ((rw & REQ_FUA) && ploop_req_delay_fua_possible(preq)) { /* Mark req that delayed flush required */ - set_bit(PLOOP_REQ_FORCE_FLUSH, &preq->state); - } else if (rw & REQ_FUA) { - postfua = 1; + preq->req_rw |= (REQ_FLUSH | REQ_FUA); + delayed_fua = 1; } rw &= ~(REQ_FLUSH | REQ_FUA); @@ -222,7 +218,8 @@ flush_bio: goto flush_bio; } - bio->bi_rw |= bw.cur->bi_rw & (REQ_FLUSH | REQ_FUA); + bio->bi_rw |= bw.cur->bi_rw & + (REQ_FLUSH | delayed_fua ? 0 : REQ_FUA); bw.bv_off += copy; size -= copy >> 9; sec += copy >> 9; diff --git a/drivers/block/ploop/map.c b/drivers/block/ploop/map.c index ae6cc15..f87fb08 100644 --- a/drivers/block/ploop/map.c +++ b/drivers/block/ploop/map.c @@ -908,6 +908,7 @@ void ploop_index_update(struct ploop_request * preq) int old_level; struct page * page; sector_t sec; + unsigned long rw; /* No way back, we are going to initiate index write. */ @@ -965,8 +966,14 @@ void ploop_index_update(struct ploop_request * preq) test_bit(PLOOP_REQ_RELOC_S, &preq->state)) set_bit(PLOOP_REQ_FORCE_FUA, &preq->state); - top_delta->io.ops->write_page(&top_delta->io, preq, page, sec, - preq->req_rw & REQ_FUA); + rw = (preq->req_rw & (REQ_FUA | REQ_FLUSH)); + + /* We've just set REQ_FLUSH in rw, ->write_page() below + will do the FLUSH */ + preq->req_rw &= ~REQ_FLUSH; + + top_delta->io.ops->write_page(&top_delta->io, preq, page, sec, rw); + put_page(page); return; @@ -1085,7 +1092,8 @@ static void map_wb_complete(struct map_node * m, int err) int delayed = 0; unsigned int idx; sector_t sec; - int fua, force_fua; + int force_fua; + unsigned long rw; /* First, complete processing of written back indices, * finally instantiate indices in mapping cache. @@ -1155,7 +1163,7 @@ static void map_wb_complete(struct map_node * m, int err) copy_index_for_wb(page, m, top_delta->level); main_preq = NULL; - fua = 0; + rw = 0; force_fua = 0; list_for_each_safe(cursor, tmp, &m->io_queue) { @@ -1175,8 +1183,11 @@ static void map_wb_complete(struct map_node * m, int err) break; } - if (preq->req_rw & REQ_FUA) - fua = 1; + rw |= (preq->req_rw & (REQ_FLUSH | REQ_FUA)); + + /* We've just set REQ_FLUSH in rw, ->write_page() below + will do the FLUSH */ + preq->req_rw &= ~REQ_FLUSH; if (test_bit(PLOOP_REQ_RELOC_A, &preq->state) || test_bit(PLOOP_REQ_RELOC_S, &preq->state)) @@ -1211,7 +1222,7 @@ static void map_wb_complete(struct map_node * m, int err) set_bit(PLOOP_REQ_FORCE_FUA, &main_preq->state); top_delta->io.ops->write_page(&top_delta->io, main_preq, page, sec, - fua ? REQ_FUA : 0); + rw); put_page(page); } diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h index 3e53b35..af222f1 100644 --- a/include/linux/ploop/ploop.h +++ b/include/linux/ploop/ploop.h @@ -475,7 +475,6 @@ enum PLOOP_REQ_DISCARD, PLOOP_REQ_RSYNC, PLOOP_REQ_FORCE_FUA, /*force fua of req write I/O by engine */ - PLOOP_REQ_FORCE_FLUSH, /*force flush by engine */ PLOOP_REQ_KAIO_FSYNC, /*force image fsync by KAIO module */ PLOOP_REQ_POST_SUBMIT, /* preq needs post_submit processing */ PLOOP_REQ_PUSH_BACKUP, /* preq was ACKed by userspace push_backup */ _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel