[PATCH v5 6/6] loop: Add support for REQ_ALLOCATE
From: Kirill Tkhai <hidden>
Date: 2020-01-22 10:58:36
Also in:
dm-devel, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
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 <redacted> --- drivers/block/loop.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 739b372a5112..bfe76d9adf09 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c@@ -581,6 +581,15 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, return 0; } +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);
@@ -604,9 +613,7 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq) * 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 +884,7 @@ 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 +894,7 @@ 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); }