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authorIlya Dryomov <idryomov@gmail.com>2019-03-26 22:20:58 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-17 09:37:55 +0300
commit2f51343153e69aad32e0520bd1e77bcc315b6d16 (patch)
tree809f7e4910479b8c0ecd1ec4d9f63fa3026dfa2b
parent5b5832ca0c6f7a8de496db56509c2e56721bcb12 (diff)
downloadlinux-2f51343153e69aad32e0520bd1e77bcc315b6d16.tar.xz
dm table: propagate BDI_CAP_STABLE_WRITES to fix sporadic checksum errors
commit eb40c0acdc342b815d4d03ae6abb09e80c0f2988 upstream. Some devices don't use blk_integrity but still want stable pages because they do their own checksumming. Examples include rbd and iSCSI when data digests are negotiated. Stacking DM (and thus LVM) on top of these devices results in sporadic checksum errors. Set BDI_CAP_STABLE_WRITES if any underlying device has it set. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/md/dm-table.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index f9cd81375f28..d76e685206b3 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1789,6 +1789,36 @@ static bool dm_table_supports_discards(struct dm_table *t)
return true;
}
+static int device_requires_stable_pages(struct dm_target *ti,
+ struct dm_dev *dev, sector_t start,
+ sector_t len, void *data)
+{
+ struct request_queue *q = bdev_get_queue(dev->bdev);
+
+ return q && bdi_cap_stable_pages_required(q->backing_dev_info);
+}
+
+/*
+ * If any underlying device requires stable pages, a table must require
+ * them as well. Only targets that support iterate_devices are considered:
+ * don't want error, zero, etc to require stable pages.
+ */
+static bool dm_table_requires_stable_pages(struct dm_table *t)
+{
+ struct dm_target *ti;
+ unsigned i;
+
+ for (i = 0; i < dm_table_get_num_targets(t); i++) {
+ ti = dm_table_get_target(t, i);
+
+ if (ti->type->iterate_devices &&
+ ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
+ return true;
+ }
+
+ return false;
+}
+
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
struct queue_limits *limits)
{
@@ -1838,6 +1868,15 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
dm_table_verify_integrity(t);
/*
+ * Some devices don't use blk_integrity but still want stable pages
+ * because they do their own checksumming.
+ */
+ if (dm_table_requires_stable_pages(t))
+ q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
+ else
+ q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
+
+ /*
* Determine whether or not this queue's I/O timings contribute
* to the entropy pool, Only request-based targets use this.
* Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not