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.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Reported-by: Lukas Straub <lukasstraub2@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/md/dm-bufio.c | 6 ++++
drivers/md/dm-integrity.c | 60 +++++++++++++++++++++++++++++++++++++---------
include/linux/dm-bufio.h | 1
3 files changed, 56 insertions(+), 11 deletions(-)
Index: linux-2.6/drivers/md/dm-integrity.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-integrity.c 2021-01-07 17:22:39.000000000 +0100
+++ linux-2.6/drivers/md/dm-integrity.c 2021-01-08 15:51:19.000000000 +0100
@@ -1379,12 +1379,52 @@ thorough_test:
#undef MAY_BE_HASH
}
-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)
@@ -2110,7 +2150,7 @@ offload_to_thread:
if (unlikely(dio->op == REQ_OP_DISCARD) && likely(ic->mode != 'D')) {
integrity_metadata(&dio->work);
- dm_integrity_flush_buffers(ic);
+ dm_integrity_flush_buffers(ic, false);
dio->in_flight = (atomic_t)ATOMIC_INIT(1);
dio->completion = NULL;
@@ -2195,7 +2235,7 @@ static void integrity_commit(struct work
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;
}
@@ -2409,7 +2449,7 @@ 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)
@@ -2451,7 +2491,7 @@ static void recalc_write_super(struct dm
{
int r;
- dm_integrity_flush_buffers(ic);
+ dm_integrity_flush_buffers(ic, false);
if (dm_integrity_failed(ic))
return;
@@ -2654,7 +2694,7 @@ static void bitmap_flush_work(struct wor
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;
@@ -2663,9 +2703,7 @@ static void bitmap_flush_work(struct wor
add_new_range_and_wait(ic, &range);
spin_unlock_irq(&ic->endio_wait.lock);
- dm_integrity_flush_buffers(ic);
- if (ic->meta_dev)
- blkdev_issue_flush(ic->dev->bdev, GFP_NOIO);
+ dm_integrity_flush_buffers(ic, true);
limit = ic->provided_data_sectors;
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) {
@@ -2934,11 +2972,11 @@ static void dm_integrity_postsuspend(str
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);
Index: linux-2.6/include/linux/dm-bufio.h
===================================================================
--- linux-2.6.orig/include/linux/dm-bufio.h 2020-09-05 10:01:42.000000000 +0200
+++ linux-2.6/include/linux/dm-bufio.h 2021-01-08 15:12:31.000000000 +0100
@@ -150,6 +150,7 @@ void dm_bufio_set_minimum_buffers(struct
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);
Index: linux-2.6/drivers/md/dm-bufio.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-bufio.c 2021-01-08 15:11:20.000000000 +0100
+++ linux-2.6/drivers/md/dm-bufio.c 2021-01-08 15:12:25.000000000 +0100
@@ -1534,6 +1534,12 @@ sector_t dm_bufio_get_device_size(struct
}
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;
--
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