[PATCH 5.4 24/76] dm integrity: fix flush with external metadata device

Greg Kroah-Hartman
2021-01-18T19:11:31Z

From: Mikulas Patocka <mpatocka@redhat.com>

[ Upstream commit 9b5948267adc9e689da609eb61cf7ed49cae5fa8 ]

With external metadata device, flush requests are not passed down to the
data device.

Fix this by submitting the flush request in dm_integrity_flush_buffers. In
order to not degrade performance, we overlap the data device flush with
the metadata device flush.

Reported-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/dm-bufio.c | 6 +++++
drivers/md/dm-integrity.c | 56 +++++++++++++++++++++++++++++++++------
include/linux/dm-bufio.h | 1 +
3 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 2d519c2235626..a9529dc2b26e6 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1446,6 +1446,12 @@ sector_t dm_bufio_get_device_size(struct dm_bufio_client *c)
}
EXPORT_SYMBOL_GPL(dm_bufio_get_device_size);

+struct dm_io_client *dm_bufio_get_dm_io_client(struct dm_bufio_client *c)
+{
+ return c->dm_io;
+}
+EXPORT_SYMBOL_GPL(dm_bufio_get_dm_io_client);
+
sector_t dm_bufio_get_block_number(struct dm_buffer *b)
{
return b->block;
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index d99cd45874531..25efe382e78fa 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1343,12 +1343,52 @@ static int dm_integrity_rw_tag(struct dm_integrity_c *ic, unsigned char *tag, se
return 0;
}

-static void dm_integrity_flush_buffers(struct dm_integrity_c *ic)
+struct flush_request {
+ struct dm_io_request io_req;
+ struct dm_io_region io_reg;
+ struct dm_integrity_c *ic;
+ struct completion comp;
+};
+
+static void flush_notify(unsigned long error, void *fr_)
+{
+ struct flush_request *fr = fr_;
+ if (unlikely(error != 0))
+ dm_integrity_io_error(fr->ic, "flusing disk cache", -EIO);
+ complete(&fr->comp);
+}
+
+static void dm_integrity_flush_buffers(struct dm_integrity_c *ic, bool flush_data)
{
int r;
+
+ struct flush_request fr;
+
+ if (!ic->meta_dev)
+ flush_data = false;
+ if (flush_data) {
+ fr.io_req.bi_op = REQ_OP_WRITE,
+ fr.io_req.bi_op_flags = REQ_PREFLUSH | REQ_SYNC,
+ fr.io_req.mem.type = DM_IO_KMEM,
+ fr.io_req.mem.ptr.addr = NULL,
+ fr.io_req.notify.fn = flush_notify,
+ fr.io_req.notify.context = &fr;
+ fr.io_req.client = dm_bufio_get_dm_io_client(ic->bufio),
+ fr.io_reg.bdev = ic->dev->bdev,
+ fr.io_reg.sector = 0,
+ fr.io_reg.count = 0,
+ fr.ic = ic;
+ init_completion(&fr.comp);
+ r = dm_io(&fr.io_req, 1, &fr.io_reg, NULL);
+ BUG_ON(r);
+ }
+
r = dm_bufio_write_dirty_buffers(ic->bufio);
if (unlikely(r))
dm_integrity_io_error(ic, "writing tags", r);
+
+ if (flush_data)
+ wait_for_completion(&fr.comp);
}

static void sleep_on_endio_wait(struct dm_integrity_c *ic)
@@ -2077,7 +2117,7 @@ static void integrity_commit(struct work_struct *w)
flushes = bio_list_get(&ic->flush_bio_list);
if (unlikely(ic->mode != 'J')) {
spin_unlock_irq(&ic->endio_wait.lock);
- dm_integrity_flush_buffers(ic);
+ dm_integrity_flush_buffers(ic, true);
goto release_flush_bios;
}

@@ -2287,7 +2327,7 @@ skip_io:
complete_journal_op(&comp);
wait_for_completion_io(&comp.comp);

- dm_integrity_flush_buffers(ic);
+ dm_integrity_flush_buffers(ic, true);
}

static void integrity_writer(struct work_struct *w)
@@ -2329,7 +2369,7 @@ static void recalc_write_super(struct dm_integrity_c *ic)
{
int r;

- dm_integrity_flush_buffers(ic);
+ dm_integrity_flush_buffers(ic, false);
if (dm_integrity_failed(ic))
return;

@@ -2532,7 +2572,7 @@ static void bitmap_flush_work(struct work_struct *work)
unsigned long limit;
struct bio *bio;

- dm_integrity_flush_buffers(ic);
+ dm_integrity_flush_buffers(ic, false);

range.logical_sector = 0;
range.n_sectors = ic->provided_data_sectors;
@@ -2541,7 +2581,7 @@ static void bitmap_flush_work(struct work_struct *work)
add_new_range_and_wait(ic, &range);
spin_unlock_irq(&ic->endio_wait.lock);

- dm_integrity_flush_buffers(ic);
+ dm_integrity_flush_buffers(ic, true);
if (ic->meta_dev)
blkdev_issue_flush(ic->dev->bdev, GFP_NOIO, NULL);

@@ -2812,11 +2852,11 @@ static void dm_integrity_postsuspend(struct dm_target *ti)
if (ic->meta_dev)
queue_work(ic->writer_wq, &ic->writer_work);
drain_workqueue(ic->writer_wq);
- dm_integrity_flush_buffers(ic);
+ dm_integrity_flush_buffers(ic, true);
}

if (ic->mode == 'B') {
- dm_integrity_flush_buffers(ic);
+ dm_integrity_flush_buffers(ic, true);
#if 1
/* set to 0 to test bitmap replay code */
init_journal(ic, 0, ic->journal_sections, 0);
diff --git a/include/linux/dm-bufio.h b/include/linux/dm-bufio.h
index 3c8b7d274bd9b..45ba37aaf6b78 100644
--- a/include/linux/dm-bufio.h
+++ b/include/linux/dm-bufio.h
@@ -138,6 +138,7 @@ void dm_bufio_set_minimum_buffers(struct dm_bufio_client *c, unsigned n);

unsigned dm_bufio_get_block_size(struct dm_bufio_client *c);
sector_t dm_bufio_get_device_size(struct dm_bufio_client *c);
+struct dm_io_client *dm_bufio_get_dm_io_client(struct dm_bufio_client *c);
sector_t dm_bufio_get_block_number(struct dm_buffer *b);
void *dm_bufio_get_block_data(struct dm_buffer *b);
void *dm_bufio_get_aux_data(struct dm_buffer *b);
--
2.27.0