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authorDamien Le Moal <damien.lemoal@wdc.com>2017-05-09 02:40:43 +0300
committerMike Snitzer <snitzer@redhat.com>2017-06-19 18:03:50 +0300
commitdd88d313bef0277e27597aa394607ed26c658724 (patch)
tree66c91180024d7314d273690b48648fb019f5d876 /include/linux/device-mapper.h
parentd2c3c8dcb5987b8352e82089c79a41b6e17e28d2 (diff)
downloadlinux-dd88d313bef0277e27597aa394607ed26c658724.tar.xz
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 'include/linux/device-mapper.h')
-rw-r--r--include/linux/device-mapper.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 19bc7fdfd6da..186ef74009cb 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -237,6 +237,12 @@ typedef unsigned (*dm_num_write_bios_fn) (struct dm_target *ti, struct bio *bio)
#define DM_TARGET_PASSES_INTEGRITY 0x00000020
#define dm_target_passes_integrity(type) ((type)->features & DM_TARGET_PASSES_INTEGRITY)
+/*
+ * Indicates that a target supports host-managed zoned block devices.
+ */
+#define DM_TARGET_ZONED_HM 0x00000040
+#define dm_target_supports_zoned_hm(type) ((type)->features & DM_TARGET_ZONED_HM)
+
struct dm_target {
struct dm_table *table;
struct target_type *type;