Support for new modifier of REQ_OP_WRITE_ZEROES command. This results in allocation extents in backing file instead of actual blocks zeroing.
Signed-off-by: Kirill Tkhai <[email protected]> Reviewed-by: Bob Liu <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> --- drivers/block/loop.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 739b372a5112..0704167a5aaa 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -581,6 +581,16 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, return 0; } +/* Convert REQ_OP_WRITE_ZEROES modifiers into fallocate mode */ +static unsigned int write_zeroes_to_fallocate_mode(unsigned int flags) +{ + if (flags & REQ_ALLOCATE) + return 0; + if (flags & REQ_NOUNMAP) + return FALLOC_FL_ZERO_RANGE; + return FALLOC_FL_PUNCH_HOLE; +} + static int do_req_filebacked(struct loop_device *lo, struct request *rq) { struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); @@ -599,14 +609,8 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq) case REQ_OP_FLUSH: return lo_req_flush(lo, rq); case REQ_OP_WRITE_ZEROES: - /* - * If the caller doesn't want deallocation, call zeroout to - * write zeroes the range. Otherwise, punch them out. - */ return lo_fallocate(lo, rq, pos, - (rq->cmd_flags & REQ_NOUNMAP) ? - FALLOC_FL_ZERO_RANGE : - FALLOC_FL_PUNCH_HOLE); + write_zeroes_to_fallocate_mode(rq->cmd_flags)); case REQ_OP_DISCARD: return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE); case REQ_OP_WRITE: @@ -877,6 +881,7 @@ static void loop_config_discard(struct loop_device *lo) q->limits.discard_alignment = 0; blk_queue_max_discard_sectors(q, 0); blk_queue_max_write_zeroes_sectors(q, 0); + blk_queue_max_allocate_sectors(q, 0); blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); return; } @@ -886,6 +891,7 @@ static void loop_config_discard(struct loop_device *lo) blk_queue_max_discard_sectors(q, UINT_MAX >> 9); blk_queue_max_write_zeroes_sectors(q, UINT_MAX >> 9); + blk_queue_max_allocate_sectors(q, UINT_MAX >> 9); blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); } -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
