drbd always wants its discard wire operations to zero the blocks, so
use blkdev_issue_zeroout with the BLKDEV_ZERO_UNMAP flag instead of
reinventing it poorly.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/block/drbd/drbd_debugfs.c | 3 --
drivers/block/drbd/drbd_int.h | 6 ---
drivers/block/drbd/drbd_receiver.c | 99 ++------------------------------------
drivers/block/drbd/drbd_req.c | 6 +--
4 files changed, 7 insertions(+), 107 deletions(-)
diff --git a/drivers/block/drbd/drbd_debugfs.c b/drivers/block/drbd/drbd_debugfs.c
index de5c3ee8a790..494837e59f23 100644
--- a/drivers/block/drbd/drbd_debugfs.c
+++ b/drivers/block/drbd/drbd_debugfs.c
@@ -236,9 +236,6 @@ static void seq_print_peer_request_flags(struct seq_file *m, struct drbd_peer_re
seq_print_rq_state_bit(m, f & EE_CALL_AL_COMPLETE_IO, &sep, "in-AL");
seq_print_rq_state_bit(m, f & EE_SEND_WRITE_ACK, &sep, "C");
seq_print_rq_state_bit(m, f & EE_MAY_SET_IN_SYNC, &sep, "set-in-sync");
-
- if (f & EE_IS_TRIM)
- __seq_print_rq_state_bit(m, f & EE_IS_TRIM_USE_ZEROOUT, &sep, "zero-out", "trim");
seq_print_rq_state_bit(m, f & EE_WRITE_SAME, &sep, "write-same");
seq_putc(m, '\n');
}
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 724d1c50fc52..d5da45bb03a6 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -437,9 +437,6 @@ enum {
/* is this a TRIM aka REQ_DISCARD? */
__EE_IS_TRIM,
- /* our lower level cannot handle trim,
- * and we want to fall back to zeroout instead */
- __EE_IS_TRIM_USE_ZEROOUT,
/* In case a barrier failed,
* we need to resubmit without the barrier flag. */
@@ -482,7 +479,6 @@ enum {
#define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO)
#define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC)
#define EE_IS_TRIM (1<<__EE_IS_TRIM)
-#define EE_IS_TRIM_USE_ZEROOUT (1<<__EE_IS_TRIM_USE_ZEROOUT)
#define EE_RESUBMITTED (1<<__EE_RESUBMITTED)
#define EE_WAS_ERROR (1<<__EE_WAS_ERROR)
#define EE_HAS_DIGEST (1<<__EE_HAS_DIGEST)
@@ -1561,8 +1557,6 @@ extern void start_resync_timer_fn(unsigned long data);
extern void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req);
/* drbd_receiver.c */
-extern int drbd_issue_discard_or_zero_out(struct drbd_device *device,
- sector_t start, unsigned int nr_sectors, bool discard);
extern int drbd_receiver(struct drbd_thread *thi);
extern int drbd_ack_receiver(struct drbd_thread *thi);
extern void drbd_send_ping_wf(struct work_struct *ws);
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index aa6bf9692eff..8641776f043a 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1448,105 +1448,14 @@ void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backin
drbd_info(resource, "Method to ensure write ordering: %s\n", write_ordering_str[resource->write_ordering]);
}
-/*
- * We *may* ignore the discard-zeroes-data setting, if so configured.
- *
- * Assumption is that it "discard_zeroes_data=0" is only because the backend
- * may ignore partial unaligned discards.
- *
- * LVM/DM thin as of at least
- * LVM version: 2.02.115(2)-RHEL7 (2015-01-28)
- * Library version: 1.02.93-RHEL7 (2015-01-28)
- * Driver version: 4.29.0
- * still behaves this way.
- *
- * For unaligned (wrt. alignment and granularity) or too small discards,
- * we zero-out the initial (and/or) trailing unaligned partial chunks,
- * but discard all the aligned full chunks.
- *
- * At least for LVM/DM thin, the result is effectively "discard_zeroes_data=1".
- */
-int drbd_issue_discard_or_zero_out(struct drbd_device *device, sector_t start, unsigned int nr_sectors, bool discard)
-{
- struct block_device *bdev = device->ldev->backing_bdev;
- struct request_queue *q = bdev_get_queue(bdev);
- sector_t tmp, nr;
- unsigned int max_discard_sectors, granularity;
- int alignment;
- int err = 0;
-
- if (!discard)
- goto zero_out;
-
- /* Zero-sector (unknown) and one-sector granularities are the same. */
- granularity = max(q->limits.discard_granularity >> 9, 1U);
- alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
-
- max_discard_sectors = min(q->limits.max_discard_sectors, (1U << 22));
- max_discard_sectors -= max_discard_sectors % granularity;
- if (unlikely(!max_discard_sectors))
- goto zero_out;
-
- if (nr_sectors < granularity)
- goto zero_out;
-
- tmp = start;
- if (sector_div(tmp, granularity) != alignment) {
- if (nr_sectors < 2*granularity)
- goto zero_out;
- /* start + gran - (start + gran - align) % gran */
- tmp = start + granularity - alignment;
- tmp = start + granularity - sector_div(tmp, granularity);
-
- nr = tmp - start;
- err |= blkdev_issue_zeroout(bdev, start, nr, GFP_NOIO, 0);
- nr_sectors -= nr;
- start = tmp;
- }
- while (nr_sectors >= granularity) {
- nr = min_t(sector_t, nr_sectors, max_discard_sectors);
- err |= blkdev_issue_discard(bdev, start, nr, GFP_NOIO, 0);
- nr_sectors -= nr;
- start += nr;
- }
- zero_out:
- if (nr_sectors) {
- err |= blkdev_issue_zeroout(bdev, start, nr_sectors, GFP_NOIO, 0);
- }
- return err != 0;
-}
-
-static bool can_do_reliable_discards(struct drbd_device *device)
-{
- struct request_queue *q = bdev_get_queue(device->ldev->backing_bdev);
- struct disk_conf *dc;
- bool can_do;
-
- if (!blk_queue_discard(q))
- return false;
-
- if (q->limits.discard_zeroes_data)
- return true;
-
- rcu_read_lock();
- dc = rcu_dereference(device->ldev->disk_conf);
- can_do = dc->discard_zeroes_if_aligned;
- rcu_read_unlock();
- return can_do;
-}
-
static void drbd_issue_peer_discard(struct drbd_device *device, struct drbd_peer_request *peer_req)
{
- /* If the backend cannot discard, or does not guarantee
- * read-back zeroes in discarded ranges, we fall back to
- * zero-out. Unless configuration specifically requested
- * otherwise. */
- if (!can_do_reliable_discards(device))
- peer_req->flags |= EE_IS_TRIM_USE_ZEROOUT;
+ struct block_device *bdev = device->ldev->backing_bdev;
- if (drbd_issue_discard_or_zero_out(device, peer_req->i.sector,
- peer_req->i.size >> 9, !(peer_req->flags & EE_IS_TRIM_USE_ZEROOUT)))
+ if (blkdev_issue_zeroout(bdev, peer_req->i.sector, peer_req->i.size >> 9,
+ GFP_NOIO, BLKDEV_ZERO_UNMAP))
peer_req->flags |= EE_WAS_ERROR;
+
drbd_endio_write_sec_final(peer_req);
}
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 652114ae1a8a..bdd42b8360cc 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1148,10 +1148,10 @@ static int drbd_process_write_request(struct drbd_request *req)
static void drbd_process_discard_req(struct drbd_request *req)
{
- int err = drbd_issue_discard_or_zero_out(req->device,
- req->i.sector, req->i.size >> 9, true);
+ struct block_device *bdev = req->device->ldev->backing_bdev;
- if (err)
+ if (blkdev_issue_zeroout(bdev, req->i.sector, req->i.size >> 9,
+ GFP_NOIO, BLKDEV_ZERO_UNMAP))
req->private_bio->bi_error = -EIO;
bio_endio(req->private_bio);
}
--
2.11.0
