Merge patch series "Use block pr_ops in LIO"

Mike Christie <michael.christie@oracle.com> says:

The patches in this thread allow us to use the block pr_ops with LIO's
target_core_iblock module to support cluster applications in VMs. They
were built over Linus's tree. They also apply over linux-next and
Martin's tree and Jens's trees.

Currently, to use windows clustering or linux clustering (pacemaker +
cluster labs scsi fence agents) in VMs with LIO and vhost-scsi, you
have to use tcmu or pscsi or use a cluster aware FS/framework for the
LIO pr file. Setting up a cluster FS/framework is pain and waste when
your real backend device is already a distributed device, and pscsi
and tcmu are nice for specific use cases, but iblock gives you the
best performance and allows you to use stacked devices like
dm-multipath. So these patches allow iblock to work like pscsi/tcmu
where they can pass a PR command to the backend module. And then
iblock will use the pr_ops to pass the PR command to the real devices
similar to what we do for unmap today.

The patches are separated in the following groups:

Patch 1 - 2:

 - Add block layer callouts for reading reservations and rename reservation
   error code.

Patch 3 - 5:

 - SCSI support for new callouts.

Patch 6:

 - DM support for new callouts.

Patch 7 - 13:

 - NVMe support for new callouts.

Patch 14 - 18:

 - LIO support for new callouts.

This patchset has been tested with the libiscsi PGR ops and with
window's failover cluster verification test. Note that for scsi
backend devices we need this patchset:

https://lore.kernel.org/linux-scsi/20230123221046.125483-1-michael.christie@oracle.com/T/#m4834a643ffb5bac2529d65d40906d3cfbdd9b1b7

to handle UAs. To reduce the size of this patchset that's being done
separately to make reviewing easier. And to make merging easier this
patchset and the one above do not have any conflicts so can be merged
in different trees.

Link: https://lore.kernel.org/r/20230407200551.12660-1-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 8 insertions, 3 deletions

diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index a3c193df25b3..739df993aa5e 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -62,13 +62,17 @@ struct target_backend_ops {
 	struct configfs_attribute **tb_dev_action_attrs;
 };
 
-struct sbc_ops {
+struct exec_cmd_ops {
 	sense_reason_t (*execute_rw)(struct se_cmd *cmd, struct scatterlist *,
 				     u32, enum dma_data_direction);
 	sense_reason_t (*execute_sync_cache)(struct se_cmd *cmd);
 	sense_reason_t (*execute_write_same)(struct se_cmd *cmd);
 	sense_reason_t (*execute_unmap)(struct se_cmd *cmd,
 				sector_t lba, sector_t nolb);
+	sense_reason_t (*execute_pr_out)(struct se_cmd *cmd, u8 sa, u64 key,
+					 u64 sa_key, u8 type, bool aptpl);
+	sense_reason_t (*execute_pr_in)(struct se_cmd *cmd, u8 sa,
+					unsigned char *param_data);
 };
 
 int	transport_backend_register(const struct target_backend_ops *);
@@ -86,7 +90,7 @@ sense_reason_t	spc_emulate_report_luns(struct se_cmd *cmd);
 sense_reason_t	spc_emulate_inquiry_std(struct se_cmd *, unsigned char *);
 sense_reason_t	spc_emulate_evpd_83(struct se_cmd *, unsigned char *);
 
-sense_reason_t	sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops);
+sense_reason_t	sbc_parse_cdb(struct se_cmd *cmd, struct exec_cmd_ops *ops);
 u32	sbc_get_device_rev(struct se_device *dev);
 u32	sbc_get_device_type(struct se_device *dev);
 sector_t	sbc_get_write_same_sectors(struct se_cmd *cmd);
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 5f8e96f1516f..159567359bbb 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -880,7 +880,8 @@ struct target_opcode_descriptor {
 	u8			specific_timeout;
 	u16			nominal_timeout;
 	u16			recommended_timeout;
-	bool			(*enabled)(struct se_cmd *cmd);
+	bool			(*enabled)(struct target_opcode_descriptor *descr,
+					   struct se_cmd *cmd);
 	void			(*update_usage_bits)(u8 *usage_bits,
 						     struct se_device *dev);
 	u8			usage_bits[];