| Message ID | 554C51D5.30202@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Mike, On Fri, 2015-05-08 at 01:04 -0500, Mike Christie wrote: > On 05/06/2015 01:48 AM, Christoph Hellwig wrote: > >>> As for the API: I would much prefer to have things at the block layer > >>> in some form than adding side band protocol for specific functionality. > >>> > >> > >> Ok. For what you need for your NFS cluster work, will you have a > >> request_queue or block_device or gendisk? > > > > All of them. It's just another consumer of the in-kernel block devices > > interface. > > Will users use lio with what you are working on? > > I ask because I am thinking it might be better to implement my own > se_subsystem_api and sbc_ops structs and in my backend just make libceph > calls directly for callouts like sbc_ops->execute_rw. So I would not have > a block_device or request_queue if I went that route. > > If I do my own backend, for reset support (PR support will be similar > with callouts added to the se_subsystem_api) I would just need the patch > below. <nod> I think extending se_subsystem_api will be the preferred approach for supporting backend active/active distributed LUN_RESET. > > diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c > index 315ec34..b5a3b68 100644 > --- a/drivers/target/target_core_tmr.c > +++ b/drivers/target/target_core_tmr.c > @@ -323,7 +323,7 @@ static void core_tmr_drain_state_list( > } > } > > -int core_tmr_lun_reset( > +int target_core_local_tmr_lun_reset( > struct se_device *dev, > struct se_tmr_req *tmr, > struct list_head *preempt_and_abort_list, > @@ -386,4 +386,18 @@ int core_tmr_lun_reset( > dev->transport->name); > return 0; > } > +EXPORT_SYMBOL(target_core_local_tmr_lun_reset); > > +int core_tmr_lun_reset( > + struct se_device *dev, > + struct se_tmr_req *tmr, > + struct list_head *preempt_and_abort_list, > + struct se_cmd *prout_cmd) > +{ > + if (dev->transport->reset_device) > + return dev->transport->reset_device(dev); > + else > + return target_core_local_tmr_lun_reset(dev, tmr, > + preempt_and_abort_list, > + prout_cmd); > +} > diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h > index d61be72..faad6c4 100644 > --- a/include/target/target_core_backend.h > +++ b/include/target/target_core_backend.h > @@ -31,6 +31,7 @@ struct se_subsystem_api { > struct se_device *(*alloc_device)(struct se_hba *, const char *); > int (*configure_device)(struct se_device *); > void (*free_device)(struct se_device *device); > + int (*reset_device)(struct se_device *); > > ssize_t (*set_configfs_dev_params)(struct se_device *, > const char *, ssize_t); > @@ -139,4 +139,7 @@ int se_dev_set_max_sectors(struct se_device *, u32); > int se_dev_set_optimal_sectors(struct se_device *, u32); > int se_dev_set_block_size(struct se_device *, u32); > > +int target_core_local_tmr_lun_reset(struct se_device *, struct se_tmr_req *, > + struct list_head *, struct se_cmd *); > + > #endif /* TARGET_CORE_BACKEND_H */ > The backend driver will also need to enforce it's own TAS setting when providing a custom LUN_RESET callback in order to disable this logic within target_core_mod. For persistent reservations ops, se_subsystem_api will require a PREEMPT_AND_ABORT specific callback too, yes..? Do you see any additional SPC-3 PR specific required callbacks..? --nab -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, May 08, 2015 at 01:04:05AM -0500, Mike Christie wrote: > > All of them. It's just another consumer of the in-kernel block devices > > interface. > > Will users use lio with what you are working on? It's the other way around. The pNFS block device uses a block device it wants to use persistent reservations on. If we do have a proper in-kernel API for that it could also work on say RBD and NVMe as long as they provide a mapping for SCSI3 PRs. For NVMe that exists as a spec, and for RBD it seems like you're about to deliver one. > I ask because I am thinking it might be better to implement my own > se_subsystem_api and sbc_ops structs and in my backend just make libceph > calls directly for callouts like sbc_ops->execute_rw. So I would not have > a block_device or request_queue if I went that route. > > If I do my own backend, for reset support (PR support will be similar > with callouts added to the se_subsystem_api) I would just need the patch > below. It's defintively simpler, so for prototyping it might be the way to go. I think in the long run going for a general block device API will be more useful for everyone involved. -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c index 315ec34..b5a3b68 100644 --- a/drivers/target/target_core_tmr.c +++ b/drivers/target/target_core_tmr.c @@ -323,7 +323,7 @@ static void core_tmr_drain_state_list( } } -int core_tmr_lun_reset( +int target_core_local_tmr_lun_reset( struct se_device *dev, struct se_tmr_req *tmr, struct list_head *preempt_and_abort_list, @@ -386,4 +386,18 @@ int core_tmr_lun_reset( dev->transport->name); return 0; } +EXPORT_SYMBOL(target_core_local_tmr_lun_reset); +int core_tmr_lun_reset( + struct se_device *dev, + struct se_tmr_req *tmr, + struct list_head *preempt_and_abort_list, + struct se_cmd *prout_cmd) +{ + if (dev->transport->reset_device) + return dev->transport->reset_device(dev); + else + return target_core_local_tmr_lun_reset(dev, tmr, + preempt_and_abort_list, + prout_cmd); +} diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h index d61be72..faad6c4 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -31,6 +31,7 @@ struct se_subsystem_api { struct se_device *(*alloc_device)(struct se_hba *, const char *); int (*configure_device)(struct se_device *); void (*free_device)(struct se_device *device); + int (*reset_device)(struct se_device *); ssize_t (*set_configfs_dev_params)(struct se_device *, const char *, ssize_t); @@ -139,4 +139,7 @@ int se_dev_set_max_sectors(struct se_device *, u32); int se_dev_set_optimal_sectors(struct se_device *, u32); int se_dev_set_block_size(struct se_device *, u32); +int target_core_local_tmr_lun_reset(struct se_device *, struct se_tmr_req *, + struct list_head *, struct se_cmd *); + #endif /* TARGET_CORE_BACKEND_H */