Logical neighbouring blocks usually are not physically neighbours, so we may issue discard only for a single block. Thus, we request block layer to split discard requests in (1 << (cluster_log + 9)) bytes bios.
This is the basis. Later we may introduce some performance improvements for corner cases on top of this. Signed-off-by: Kirill Tkhai <[email protected]> --- drivers/block/ploop/dev.c | 6 +++--- drivers/block/ploop/io_direct.c | 1 + drivers/block/ploop/io_kaio.c | 5 +---- include/linux/ploop/ploop.h | 11 +++++++++++ 4 files changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c index 9ac436201b1b..bf508a9b1bc8 100644 --- a/drivers/block/ploop/dev.c +++ b/drivers/block/ploop/dev.c @@ -4026,10 +4026,10 @@ static int ploop_start(struct ploop_device * plo, struct block_device *bdev) blk_queue_merge_bvec(q, ploop_merge_bvec); blk_queue_flush(q, REQ_FLUSH); - if (top_delta->io.ops->queue_settings) - top_delta->io.ops->queue_settings(&top_delta->io, q); + top_delta->io.ops->queue_settings(&top_delta->io, q); + /* REQ_WRITE_SAME is not supported */ + blk_queue_max_write_same_sectors(q, 0); - blk_queue_max_discard_sectors(q, INT_MAX); queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); queue_flag_clear_unlocked(QUEUE_FLAG_STANDBY, q); diff --git a/drivers/block/ploop/io_direct.c b/drivers/block/ploop/io_direct.c index b0d7095864fc..18563eaa4f1a 100644 --- a/drivers/block/ploop/io_direct.c +++ b/drivers/block/ploop/io_direct.c @@ -1776,6 +1776,7 @@ static int dio_congested(struct ploop_io * io, int bits) static void dio_queue_settings(struct ploop_io * io, struct request_queue * q) { + ploop_set_discard_limits(io->plo); blk_queue_stack_limits(q, bdev_get_queue(io->files.bdev)); } diff --git a/drivers/block/ploop/io_kaio.c b/drivers/block/ploop/io_kaio.c index f5d9936d4cd4..84da1cec5643 100644 --- a/drivers/block/ploop/io_kaio.c +++ b/drivers/block/ploop/io_kaio.c @@ -1078,10 +1078,7 @@ static void kaio_unplug(struct ploop_io * io) static void kaio_queue_settings(struct ploop_io * io, struct request_queue * q) { blk_set_stacking_limits(&q->limits); - blk_queue_max_write_same_sectors(q, 0); - - q->limits.discard_alignment = PAGE_SIZE; - q->limits.discard_granularity = PAGE_SIZE; + ploop_set_discard_limits(io->plo); } static void kaio_issue_flush(struct ploop_io * io, struct ploop_request *preq) diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h index 71a55573bdf6..b209c9f096a8 100644 --- a/include/linux/ploop/ploop.h +++ b/include/linux/ploop/ploop.h @@ -853,6 +853,17 @@ static inline bool whole_block(struct ploop_device * plo, struct ploop_request * return !(preq->req_sector & (cluster_size_in_sec(plo) - 1)); } +static inline void ploop_set_discard_limits(struct ploop_device *plo) +{ + struct request_queue *q = plo->queue; + /* + * In PLOOP_FMT_PLOOP1 format, neighbouring virtual clusters + * are not neighbours on backed device, so we expect block + * subsystem splits discards in single-cluster requests. + */ + q->limits.discard_granularity = cluster_size_in_bytes(plo); + q->limits.max_discard_sectors = (1 << plo->cluster_log); +} struct map_node; int ploop_fastmap(struct ploop_map * map, cluster_t block, iblock_t *result); _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
