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authorDamien Le Moal <damien.lemoal@wdc.com>2017-05-08 16:40:43 -0700
committerMike Snitzer <snitzer@redhat.com>2017-06-19 11:03:50 -0400
commitdd88d313bef0277e27597aa394607ed26c658724 (patch)
tree66c91180024d7314d273690b48648fb019f5d876 /drivers/md/dm-table.c
parentd2c3c8dcb5987b8352e82089c79a41b6e17e28d2 (diff)
dm table: add zoned block devices validation
1) Introduce DM_TARGET_ZONED_HM feature flag: The target drivers currently available will not operate correctly if a table target maps onto a host-managed zoned block device. To avoid problems, introduce the new feature flag DM_TARGET_ZONED_HM to allow a target to explicitly state that it supports host-managed zoned block devices. This feature is checked for all targets in a table if any of the table's block devices are host-managed. Note that as host-aware zoned block devices are backward compatible with regular block devices, they can be used by any of the current target types. This new feature is thus restricted to host-managed zoned block devices. 2) Check device area zone alignment: If a target maps to a zoned block device, check that the device area is aligned on zone boundaries to avoid problems with REQ_OP_ZONE_RESET operations (resetting a partially mapped sequential zone would not be possible). This also facilitates the processing of zone report with REQ_OP_ZONE_REPORT bios. 3) Check block devices zone model compatibility When setting the DM device's queue limits, several possibilities exists for zoned block devices: 1) The DM target driver may want to expose a different zone model (e.g. host-managed device emulation or regular block device on top of host-managed zoned block devices) 2) Expose the underlying zone model of the devices as-is To allow both cases, the underlying block device zone model must be set in the target limits in dm_set_device_limits() and the compatibility of all devices checked similarly to the logical block size alignment. For this last check, introduce validate_hardware_zoned_model() to check that all targets of a table have the same zone model and that the zone size of the target devices are equal. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> [Mike Snitzer refactored Damien's original work to simplify the code] Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-table.c')
-rw-r--r--drivers/md/dm-table.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 5f5eae41f804..a39bcd9b982a 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -319,6 +319,39 @@ static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
return 1;
}
+ /*
+ * If the target is mapped to zoned block device(s), check
+ * that the zones are not partially mapped.
+ */
+ if (bdev_zoned_model(bdev) != BLK_ZONED_NONE) {
+ unsigned int zone_sectors = bdev_zone_sectors(bdev);
+
+ if (start & (zone_sectors - 1)) {
+ DMWARN("%s: start=%llu not aligned to h/w zone size %u of %s",
+ dm_device_name(ti->table->md),
+ (unsigned long long)start,
+ zone_sectors, bdevname(bdev, b));
+ return 1;
+ }
+
+ /*
+ * Note: The last zone of a zoned block device may be smaller
+ * than other zones. So for a target mapping the end of a
+ * zoned block device with such a zone, len would not be zone
+ * aligned. We do not allow such last smaller zone to be part
+ * of the mapping here to ensure that mappings with multiple
+ * devices do not end up with a smaller zone in the middle of
+ * the sector range.
+ */
+ if (len & (zone_sectors - 1)) {
+ DMWARN("%s: len=%llu not aligned to h/w zone size %u of %s",
+ dm_device_name(ti->table->md),
+ (unsigned long long)len,
+ zone_sectors, bdevname(bdev, b));
+ return 1;
+ }
+ }
+
if (logical_block_size_sectors <= 1)
return 0;
@@ -456,6 +489,8 @@ static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
q->limits.alignment_offset,
(unsigned long long) start << SECTOR_SHIFT);
+ limits->zoned = blk_queue_zoned_model(q);
+
return 0;
}
@@ -1346,6 +1381,88 @@ bool dm_table_has_no_data_devices(struct dm_table *table)
return true;
}
+static int device_is_zoned_model(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);
+ enum blk_zoned_model *zoned_model = data;
+
+ return q && blk_queue_zoned_model(q) == *zoned_model;
+}
+
+static bool dm_table_supports_zoned_model(struct dm_table *t,
+ enum blk_zoned_model zoned_model)
+{
+ 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 (zoned_model == BLK_ZONED_HM &&
+ !dm_target_supports_zoned_hm(ti->type))
+ return false;
+
+ if (!ti->type->iterate_devices ||
+ !ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
+ return false;
+ }
+
+ return true;
+}
+
+static int device_matches_zone_sectors(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);
+ unsigned int *zone_sectors = data;
+
+ return q && blk_queue_zone_sectors(q) == *zone_sectors;
+}
+
+static bool dm_table_matches_zone_sectors(struct dm_table *t,
+ unsigned int zone_sectors)
+{
+ 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_matches_zone_sectors, &zone_sectors))
+ return false;
+ }
+
+ return true;
+}
+
+static int validate_hardware_zoned_model(struct dm_table *table,
+ enum blk_zoned_model zoned_model,
+ unsigned int zone_sectors)
+{
+ if (zoned_model == BLK_ZONED_NONE)
+ return 0;
+
+ if (!dm_table_supports_zoned_model(table, zoned_model)) {
+ DMERR("%s: zoned model is not consistent across all devices",
+ dm_device_name(table->md));
+ return -EINVAL;
+ }
+
+ /* Check zone size validity and compatibility */
+ if (!zone_sectors || !is_power_of_2(zone_sectors))
+ return -EINVAL;
+
+ if (!dm_table_matches_zone_sectors(table, zone_sectors)) {
+ DMERR("%s: zone sectors is not consistent across all devices",
+ dm_device_name(table->md));
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
/*
* Establish the new table's queue_limits and validate them.
*/
@@ -1355,6 +1472,8 @@ int dm_calculate_queue_limits(struct dm_table *table,
struct dm_target *ti;
struct queue_limits ti_limits;
unsigned i;
+ enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
+ unsigned int zone_sectors = 0;
blk_set_stacking_limits(limits);
@@ -1372,6 +1491,15 @@ int dm_calculate_queue_limits(struct dm_table *table,
ti->type->iterate_devices(ti, dm_set_device_limits,
&ti_limits);
+ if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
+ /*
+ * After stacking all limits, validate all devices
+ * in table support this zoned model and zone sectors.
+ */
+ zoned_model = ti_limits.zoned;
+ zone_sectors = ti_limits.chunk_sectors;
+ }
+
/* Set I/O hints portion of queue limits */
if (ti->type->io_hints)
ti->type->io_hints(ti, &ti_limits);
@@ -1396,8 +1524,42 @@ combine_limits:
dm_device_name(table->md),
(unsigned long long) ti->begin,
(unsigned long long) ti->len);
+
+ /*
+ * FIXME: this should likely be moved to blk_stack_limits(), would
+ * also eliminate limits->zoned stacking hack in dm_set_device_limits()
+ */
+ if (limits->zoned == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
+ /*
+ * By default, the stacked limits zoned model is set to
+ * BLK_ZONED_NONE in blk_set_stacking_limits(). Update
+ * this model using the first target model reported
+ * that is not BLK_ZONED_NONE. This will be either the
+ * first target device zoned model or the model reported
+ * by the target .io_hints.
+ */
+ limits->zoned = ti_limits.zoned;
+ }
}
+ /*
+ * Verify that the zoned model and zone sectors, as determined before
+ * any .io_hints override, are the same across all devices in the table.
+ * - this is especially relevant if .io_hints is emulating a disk-managed
+ * zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
+ * BUT...
+ */
+ if (limits->zoned != BLK_ZONED_NONE) {
+ /*
+ * ...IF the above limits stacking determined a zoned model
+ * validate that all of the table's devices conform to it.
+ */
+ zoned_model = limits->zoned;
+ zone_sectors = limits->chunk_sectors;
+ }
+ if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
+ return -EINVAL;
+
return validate_hardware_logical_block_alignment(table, limits);
}