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* [PATCH v7 00/14] nvmet: add target passthru commands support
@ 2019-08-01 23:44 Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path() Logan Gunthorpe
                   ` (13 more replies)
  0 siblings, 14 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:44 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe

Hi,

This is v7 of the passthru patchset. This largely addresses the
feedback from v6: cleaning up the nvme_ctrl_get_by_path() and
allowing multipath over fabrics to the passthru target.

Multipath is now supported simply by allowing multiple connections
from the same hostnqn and overriding the appropriate cmic bit. Passing
through to multiport devices as a target is still not supported.

--

Chaitainya has asked us to take on these patches as we have an
interest in getting them into upstream. To that end, we've done
a large amount of testing, bug fixes and cleanup.

Passthru support for nvmet allows users to export an entire
NVMe controller through NVMe-oF. When exported in this way (as opposed
to exporting each namespace as a block device), all the NVMe commands
are passed to the given controller unmodified, including most admin
commands and Vendor Unique Commands (VUCs). A passthru target will
expose all namespaces for a given device to the remote host.

There are three major non-bugfix changes that we've done to the series:

1) Instead of using a seperate special passthru subsystem in
   configfs simply add a passthru directory that's analogous to
   the existing namespace directories. The directories have
   very similar attributes to namespaces but are mutually exclusive.
   If a user enables a namespaces, they can't then enable
   passthru controller and vice versa. This simplifies the code
   required to implement passthru configfs and IMO creates a much
   clearer and uniform interface.

2) Instead of taking a bare controller name (ie. "nvme1"), take a
   full device path to the controller's char device. This is more
   consistent with the regular namespaces which take a path and
   also allows users to make use of udev rules and symlinks to
   manage their controllers instead of the potentially unstable
   device names.

3) Implement block accounting for the passthru devices. This is so
   the target OS can still track device usage using /proc/diskstats.

Besides these three changes, we've also found a large number of bugs
and crashes and did a bunch of testing with KASAN, lockdep and kmemleak.
A more complete list of changes is given below.

Additionally, we've written some new blktests to test the passthru
code. A branch is available here[1] and can be submitted once these
patches are upstream.

These patches are based off of v5.3-rc1 and a git branch is available
at [2].

Thanks,

Logan

[1] https://github.com/Eideticom/blktests nvmet_passthru
[2] https://github.com/sbates130272/linux-p2pmem/ nvmet_passthru_v6

--

v7 Changes:
  1. Rebased onto v5.3-rc2
  2. Rework nvme_ctrl_get_by_path() to use filp_open() instead of
     the cdev changes that were in v6. (Per Al)
  3. Override the cmic bit to allow multipath and allow
     multiple connections from the same hostnqn. (At the same
     time I cleaned up the method of rejecting multiple connections.)
     See Patch 8)
  4. Found a bug when used with the tcp transport (See Patch 10)

v6 Changes:
  1. Rebased onto v5.3-rc1
  2. Rework configfs interface to simply be a passthru directory
     within the existing subsystem. The directory is similar to
     and consistent with a namespace directory.
  3. Have the configfs take a path instead of a bare controller name
  4. Renamed the main passthru file to io-cmd-passthru.c for consistency
     with the file and block-dev methods.
  5. Cleaned up all the CONFIG_NVME_TARGET_PASSTHRU usage to remove
     all the inline #ifdefs
  6. Restructured nvmet_passthru_make_request() a bit for clearer code
  7. Moved nvme_find_get_ns() call into nvmet_passthru_execute_cmd()
     seeing calling it in nvmet_req_init() causes a lockdep warning
     due to nvme_find_get_ns() being able to sleep.
  8. Added a check in nvmet_passthru_execute_cmd() to ensure we don't
     violate queue_max_segments or queue_max_hw_sectors and overrode
     mdts to ensure hosts don't intentionally submit commands
     that will exceed these limits.
  9. Reworked the code which ensures there's only one subsystem per
     passthru controller to use an xarray instead of a list as this is
     simpler and more easily fixed some bugs triggered by disabling
     subsystems that weren't enabled.
 10. Removed the overide of the target cntlid with the passthru cntlid;
     this seemed like a really bad idea especially in the presence of
     mixed systems as you could end up with two ctrlrs with the same
     cntlid. For now, commands that depend on cntlid are black listed.
 11. Implement block accounting for passthru so the target can track
     usage using /proc/diskstats
 12. A number of other minor bug fixes and cleanups

v5 Changes (not sent to list, from Chaitanya):
  1. Added workqueue for admin commands.
  2. Added kconfig option for the pass-thru feature.
  3. Restructure the parsing code according to your suggestion,
     call nvmet_xxx_parse_cmd() from nvmet_passthru_parse_cmd().
  4. Use pass-thru instead of pt.
  5. Several cleanups and add comments at the appropriate locations.
  6. Minimize the code for checking pass-thru ns across all the subsystems.
  7. Removed the delays in the ns related admin commands since I was
     not able to reproduce the previous bug.

v4 Changes:
  1. Add request polling interface to the block layer.
  2. Use request polling interface in the NVMEoF target passthru code
     path.
  3. Add checks suggested by Sagi for creating one target ctrl per
     passthru ctrl.
  4. Don't enable the namespace if it belongs to the configured passthru
     ctrl.
  5. Adjust the code latest kernel.

v3 Changes:
  1. Split the addition of passthru command handlers and integration
     into two different patches since we add guards to create one target
     controller per passthru controller. This way it will be easier to
     review the code.
  2. Adjust the code for 4.18.

v2 Changes:
  1. Update the new nvme core controller find API naming and
     changed the string comparison of the ctrl.
  2. Get rid of the newly added #defines for target ctrl values.
  3. Use the newly added structure members in the same patch where
     they are used. Aggregate the passthru command handling support
     and integration with nvmet-core into one patch.
  4. Introduce global NVMe Target subsystem list for connected and
     not connected subsystems on the target side.
  5. Add check when configuring the target ns and target
     passthru ctrl to allow only one target controller to be created
     for one passthru subsystem.
  6. Use the passthru ctrl cntlid when creating the
     target controller.

--

Chaitanya Kulkarni (5):
  nvme-core: export existing ctrl and ns interfaces
  nvmet: add return value to  nvmet_add_async_event()
  nvmet-passthru: update KConfig with config passthru option
  nvmet-passthru: add passthru code to process commands
  nvmet-core: don't check the data len for pt-ctrl

Logan Gunthorpe (9):
  nvme-core: introduce nvme_ctrl_get_by_path()
  nvmet: make nvmet_copy_ns_identifier() non-static
  nvmet-passthru: add enable/disable helpers
  nvmet-core: allow one host per passthru-ctrl
  nvmet-tcp: don't check data_len in nvmet_tcp_map_data()
  nvmet-configfs: introduce passthru configfs interface
  block: don't check blk_rq_is_passthrough() in blk_do_io_stat()
  block: call blk_account_io_start() in blk_execute_rq_nowait()
  nvmet-passthru: support block accounting

 block/blk-exec.c                      |   2 +
 block/blk-mq.c                        |   2 +-
 block/blk.h                           |   5 +-
 drivers/nvme/host/core.c              |  41 +-
 drivers/nvme/host/nvme.h              |   9 +
 drivers/nvme/target/Kconfig           |  10 +
 drivers/nvme/target/Makefile          |   1 +
 drivers/nvme/target/admin-cmd.c       |   4 +-
 drivers/nvme/target/configfs.c        |  99 ++++
 drivers/nvme/target/core.c            |  39 +-
 drivers/nvme/target/io-cmd-passthru.c | 683 ++++++++++++++++++++++++++
 drivers/nvme/target/nvmet.h           |  68 ++-
 drivers/nvme/target/tcp.c             |   2 +-
 13 files changed, 947 insertions(+), 18 deletions(-)
 create mode 100644 drivers/nvme/target/io-cmd-passthru.c

--
2.20.1

^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path()
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-14 14:20   ` Max Gurtovoy
  2019-08-15 11:46   ` Max Gurtovoy
  2019-08-01 23:45 ` [PATCH v7 02/14] nvme-core: export existing ctrl and ns interfaces Logan Gunthorpe
                   ` (12 subsequent siblings)
  13 siblings, 2 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe

nvme_ctrl_get_by_path() is analagous to blkdev_get_by_path() except it
gets a struct nvme_ctrl from the path to its char dev (/dev/nvme0).
It makes use of filp_open() to open the file and uses the private
data to obtain a pointer to the struct nvme_ctrl. If the fops of the
file do not match, -EINVAL is returned.

The purpose of this function is to support NVMe-OF target passthru.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/host/core.c | 24 ++++++++++++++++++++++++
 drivers/nvme/host/nvme.h |  2 ++
 2 files changed, 26 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index e6ee6f2a3da6..f72334f34a30 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2817,6 +2817,30 @@ static const struct file_operations nvme_dev_fops = {
 	.compat_ioctl	= nvme_dev_ioctl,
 };
 
+struct nvme_ctrl *nvme_ctrl_get_by_path(const char *path)
+{
+	struct nvme_ctrl *ctrl;
+	struct file *f;
+
+	f = filp_open(path, O_RDWR, 0);
+	if (IS_ERR(f))
+		return ERR_CAST(f);
+
+	if (f->f_op != &nvme_dev_fops) {
+		ctrl = ERR_PTR(-EINVAL);
+		goto out_close;
+	}
+
+	ctrl = f->private_data;
+	nvme_get_ctrl(ctrl);
+
+out_close:
+	filp_close(f, NULL);
+
+	return ctrl;
+}
+EXPORT_SYMBOL_GPL(nvme_ctrl_get_by_path);
+
 static ssize_t nvme_sysfs_reset(struct device *dev,
 				struct device_attribute *attr, const char *buf,
 				size_t count)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index ecbd90c31d0d..7e827c9e892c 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -484,6 +484,8 @@ int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp,
 extern const struct attribute_group *nvme_ns_id_attr_groups[];
 extern const struct block_device_operations nvme_ns_head_ops;
 
+struct nvme_ctrl *nvme_ctrl_get_by_path(const char *path);
+
 #ifdef CONFIG_NVME_MULTIPATH
 static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
 {
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 02/14] nvme-core: export existing ctrl and ns interfaces
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path() Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 03/14] nvmet: add return value to nvmet_add_async_event() Logan Gunthorpe
                   ` (11 subsequent siblings)
  13 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates,
	Chaitanya Kulkarni, Logan Gunthorpe

From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

We export existing nvme ctrl and ns management APIs so that target
passthru code can manage the nvme ctrl.

This is a preparation patch for implementing NVMe Over Fabric target
passthru feature.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/host/core.c | 17 +++++++++++------
 drivers/nvme/host/nvme.h |  7 +++++++
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index f72334f34a30..4445efb16a84 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -412,10 +412,11 @@ static void nvme_free_ns(struct kref *kref)
 	kfree(ns);
 }
 
-static void nvme_put_ns(struct nvme_ns *ns)
+void nvme_put_ns(struct nvme_ns *ns)
 {
 	kref_put(&ns->kref, nvme_free_ns);
 }
+EXPORT_SYMBOL_GPL(nvme_put_ns);
 
 static inline void nvme_clear_nvme_request(struct request *req)
 {
@@ -1088,7 +1089,7 @@ static int nvme_identify_ns_list(struct nvme_ctrl *dev, unsigned nsid, __le32 *n
 				    NVME_IDENTIFY_DATA_SIZE);
 }
 
-static struct nvme_id_ns *nvme_identify_ns(struct nvme_ctrl *ctrl,
+struct nvme_id_ns *nvme_identify_ns(struct nvme_ctrl *ctrl,
 		unsigned nsid)
 {
 	struct nvme_id_ns *id;
@@ -1113,6 +1114,7 @@ static struct nvme_id_ns *nvme_identify_ns(struct nvme_ctrl *ctrl,
 
 	return id;
 }
+EXPORT_SYMBOL_GPL(nvme_identify_ns);
 
 static int nvme_features(struct nvme_ctrl *dev, u8 op, unsigned int fid,
 		unsigned int dword11, void *buffer, size_t buflen, u32 *result)
@@ -1261,8 +1263,8 @@ static u32 nvme_known_admin_effects(u8 opcode)
 	return 0;
 }
 
-static u32 nvme_passthru_start(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
-								u8 opcode)
+u32 nvme_passthru_start(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
+		u8 opcode)
 {
 	u32 effects = 0;
 
@@ -1291,6 +1293,7 @@ static u32 nvme_passthru_start(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 	}
 	return effects;
 }
+EXPORT_SYMBOL_GPL(nvme_passthru_start);
 
 static void nvme_update_formats(struct nvme_ctrl *ctrl)
 {
@@ -1305,7 +1308,7 @@ static void nvme_update_formats(struct nvme_ctrl *ctrl)
 	nvme_remove_invalid_namespaces(ctrl, NVME_NSID_ALL);
 }
 
-static void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects)
+void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects)
 {
 	/*
 	 * Revalidate LBA changes prior to unfreezing. This is necessary to
@@ -1323,6 +1326,7 @@ static void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects)
 	if (effects & (NVME_CMD_EFFECTS_NIC | NVME_CMD_EFFECTS_NCC))
 		nvme_queue_scan(ctrl);
 }
+EXPORT_SYMBOL_GPL(nvme_passthru_end);
 
 static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 			struct nvme_passthru_cmd __user *ucmd)
@@ -3265,7 +3269,7 @@ static int ns_cmp(void *priv, struct list_head *a, struct list_head *b)
 	return nsa->head->ns_id - nsb->head->ns_id;
 }
 
-static struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid)
+struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 {
 	struct nvme_ns *ns, *ret = NULL;
 
@@ -3283,6 +3287,7 @@ static struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 	up_read(&ctrl->namespaces_rwsem);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(nvme_find_get_ns);
 
 static int nvme_setup_streams_ns(struct nvme_ctrl *ctrl, struct nvme_ns *ns)
 {
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 7e827c9e892c..ccd3aff675fb 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -436,6 +436,8 @@ void nvme_start_ctrl(struct nvme_ctrl *ctrl);
 void nvme_stop_ctrl(struct nvme_ctrl *ctrl);
 void nvme_put_ctrl(struct nvme_ctrl *ctrl);
 int nvme_init_identify(struct nvme_ctrl *ctrl);
+struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned int nsid);
+void nvme_put_ns(struct nvme_ns *ns);
 
 void nvme_remove_namespaces(struct nvme_ctrl *ctrl);
 
@@ -472,8 +474,13 @@ int nvme_set_features(struct nvme_ctrl *dev, unsigned int fid,
 int nvme_get_features(struct nvme_ctrl *dev, unsigned int fid,
 		      unsigned int dword11, void *buffer, size_t buflen,
 		      u32 *result);
+u32 nvme_passthru_start(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
+		u8 opcode);
+void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects);
 int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count);
 void nvme_stop_keep_alive(struct nvme_ctrl *ctrl);
+struct nvme_id_ns *nvme_identify_ns(struct nvme_ctrl *ctrl,
+		unsigned int nsid);
 int nvme_reset_ctrl(struct nvme_ctrl *ctrl);
 int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl);
 int nvme_delete_ctrl(struct nvme_ctrl *ctrl);
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 03/14] nvmet: add return value to  nvmet_add_async_event()
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path() Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 02/14] nvme-core: export existing ctrl and ns interfaces Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-14 14:26   ` Max Gurtovoy
  2019-08-01 23:45 ` [PATCH v7 04/14] nvmet: make nvmet_copy_ns_identifier() non-static Logan Gunthorpe
                   ` (10 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates,
	Chaitanya Kulkarni, Logan Gunthorpe

From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

Change the return value for nvmet_add_async_event().

This change is needed for the target passthru code to generate async
events.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[logang@deltatee.com: fixed up commit message that was no
 longer accurate]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/core.c  | 5 +++--
 drivers/nvme/target/nvmet.h | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 3a67e244e568..f7f25bdc4763 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -173,14 +173,14 @@ static void nvmet_async_event_work(struct work_struct *work)
 	}
 }
 
-void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
+bool nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
 		u8 event_info, u8 log_page)
 {
 	struct nvmet_async_event *aen;
 
 	aen = kmalloc(sizeof(*aen), GFP_KERNEL);
 	if (!aen)
-		return;
+		return false;
 
 	aen->event_type = event_type;
 	aen->event_info = event_info;
@@ -191,6 +191,7 @@ void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
 	mutex_unlock(&ctrl->lock);
 
 	schedule_work(&ctrl->async_event_work);
+	return true;
 }
 
 static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index c51f8dd01dc4..217a787952e8 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -441,7 +441,7 @@ void nvmet_port_disc_changed(struct nvmet_port *port,
 		struct nvmet_subsys *subsys);
 void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
 		struct nvmet_host *host);
-void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
+bool nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
 		u8 event_info, u8 log_page);
 
 #define NVMET_QUEUE_SIZE	1024
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 04/14] nvmet: make nvmet_copy_ns_identifier() non-static
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (2 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 03/14] nvmet: add return value to nvmet_add_async_event() Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-14 14:29   ` Max Gurtovoy
  2019-08-01 23:45 ` [PATCH v7 05/14] nvmet-passthru: update KConfig with config passthru option Logan Gunthorpe
                   ` (9 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe,
	Chaitanya Kulkarni

This function will be needed by the upcoming passthru code.

[chaitanya.kulkarni@wdc.com: this was factored out of a patch
 originally authored by Chaitanya]
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/admin-cmd.c | 4 ++--
 drivers/nvme/target/nvmet.h     | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 4dc12ea52f23..eeb24f606d00 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -506,8 +506,8 @@ static void nvmet_execute_identify_nslist(struct nvmet_req *req)
 	nvmet_req_complete(req, status);
 }
 
-static u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
-				    void *id, off_t *off)
+u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
+			     void *id, off_t *off)
 {
 	struct nvme_ns_id_desc desc = {
 		.nidt = type,
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 217a787952e8..d1a0a3190a24 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -489,6 +489,8 @@ u16 nvmet_bdev_flush(struct nvmet_req *req);
 u16 nvmet_file_flush(struct nvmet_req *req);
 void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid);
 
+u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
+			     void *id, off_t *off);
 static inline u32 nvmet_rw_len(struct nvmet_req *req)
 {
 	return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 05/14] nvmet-passthru: update KConfig with config passthru option
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (3 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 04/14] nvmet: make nvmet_copy_ns_identifier() non-static Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-14 14:31   ` Max Gurtovoy
  2019-08-01 23:45 ` [PATCH v7 06/14] nvmet-passthru: add passthru code to process commands Logan Gunthorpe
                   ` (8 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates,
	Chaitanya Kulkarni, Logan Gunthorpe

From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

This patch updates KConfig file for the NVMeOF target where we add new
option so that user can selectively enable/disable passthru code.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[logang@deltatee.com: fixed some of the wording in the help message]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/Kconfig | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
index d7f48c0fb311..2478cb5a932d 100644
--- a/drivers/nvme/target/Kconfig
+++ b/drivers/nvme/target/Kconfig
@@ -15,6 +15,16 @@ config NVME_TARGET
 	  To configure the NVMe target you probably want to use the nvmetcli
 	  tool from http://git.infradead.org/users/hch/nvmetcli.git.
 
+config NVME_TARGET_PASSTHRU
+	bool "NVMe Target Passthrough support"
+	depends on NVME_CORE
+	depends on NVME_TARGET
+	help
+	  This enables target side NVMe passthru controller support for the
+	  NVMe Over Fabrics protocol. It allows for hosts to manage and
+	  directly access an actual NVMe controller residing on the target
+	  side, incuding executing Vendor Unique Commands.
+
 config NVME_TARGET_LOOP
 	tristate "NVMe loopback device support"
 	depends on NVME_TARGET
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 06/14] nvmet-passthru: add passthru code to process commands
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (4 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 05/14] nvmet-passthru: update KConfig with config passthru option Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers Logan Gunthorpe
                   ` (7 subsequent siblings)
  13 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates,
	Chaitanya Kulkarni, Logan Gunthorpe

From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

This patch adds passthru command handling capability for the NVMeOF
target and exports passthru APIs which are used to integrate passthru
code with nvmet-core. We add passthru ns member to the target request
to hold the ns reference for respective commands.

The new file io-cmd-passthru.c handles passthru cmd parsing and execution.
In the passthru mode, we create a block layer request from the nvmet
request and map the data on to the block layer request. For handling the
side effects of the passthru admin commands we add two functions similar
to the nvme_passthru[start|end]() functions present in the nvme-core. We
explicitly blacklist the commands at the time of parsing, which allows
us to route the fabric commands through default code path.

We introduce new passthru workqueue similar to the one we have for the
file backend for NVMeOF target to execute the NVMe Admin passthru
commands.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[logang@deltatee.com:
   * renamed passthru-cmd.c to io-cmd-passthru.c for consistency
   * squashed "update target makefile for passthru"
   * squashed "integrate passthru request processing"
   * added appropriate CONFIG_NVME_TARGET_PASSTHRU #ifdefs
   * pushed passthru_wq into passthrtu.c and introduced
     nvmet_passthru_init() and nvmet_passthru_destroy() to avoid
     inline #ifdef mess
   * renamed nvmet_passthru_ctrl() to nvmet_req_passthru_ctrl()
     and provided nvmet_passthr_ctrl() to get the ctrl from a subsys
   * fixed failure path in nvmet_passthru_execute_cmd() to ensure
     we always complete the request (with an error when appropriate)
   * restructered out nvmet_passthru_make_request() and
     nvmet_passthru_execute_cmd() to create nvmet_passthru_map_sg()
     which makes the code simpler and more readable.
   * move call to nvme_find_get_ns() into nvmet_passthru_execute_cmd()
     to prevent a lockdep error. nvme_find_get_ns() takes a
     lock and can sleep but nvme_init_req() is called while
     hctx_lock() is held (in the loop transport) and therefore
     should not sleep.
   * added check in nvmet_passthru_execute_cmd() to ensure we don't
     violate queue_max_segments or queue_max_hw_sectors.
   * added nvmet_passthru_set_mdts() to prevent requests that
     exceed max_segments
   * force setting cmic bit to support multipath for connections
     to the target
   * dropped le16_to_cpu() conversion in nvmet_passthru_req_done() as
     it's currently already done in nvme_end_request()
   * unabbreviated 'VUC' in a comment as it's not a commonly known
     acronym
   * removed unnecessary inline tags on static functions
   * minor edits to commit message
]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/Makefile          |   1 +
 drivers/nvme/target/core.c            |  11 +-
 drivers/nvme/target/io-cmd-passthru.c | 572 ++++++++++++++++++++++++++
 drivers/nvme/target/nvmet.h           |  46 +++
 4 files changed, 629 insertions(+), 1 deletion(-)
 create mode 100644 drivers/nvme/target/io-cmd-passthru.c

diff --git a/drivers/nvme/target/Makefile b/drivers/nvme/target/Makefile
index 2b33836f3d3e..bf57799fde63 100644
--- a/drivers/nvme/target/Makefile
+++ b/drivers/nvme/target/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_NVME_TARGET_TCP)		+= nvmet-tcp.o
 
 nvmet-y		+= core.o configfs.o admin-cmd.o fabrics-cmd.o \
 			discovery.o io-cmd-file.o io-cmd-bdev.o
+nvmet-$(CONFIG_NVME_TARGET_PASSTHRU)	+= io-cmd-passthru.o
 nvme-loop-y	+= loop.o
 nvmet-rdma-y	+= rdma.o
 nvmet-fc-y	+= fc.o
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index f7f25bdc4763..50c01b2da568 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -895,6 +895,8 @@ bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 	if (unlikely(!req->sq->ctrl))
 		/* will return an error for any Non-connect command: */
 		status = nvmet_parse_connect_cmd(req);
+	else if (nvmet_req_passthru_ctrl(req))
+		status = nvmet_parse_passthru_cmd(req);
 	else if (likely(req->sq->qid != 0))
 		status = nvmet_parse_io_cmd(req);
 	else if (nvme_is_fabrics(req->cmd))
@@ -1462,11 +1464,15 @@ static int __init nvmet_init(void)
 
 	nvmet_ana_group_enabled[NVMET_DEFAULT_ANA_GRPID] = 1;
 
+	error = nvmet_passthru_init();
+	if (error)
+		goto out;
+
 	buffered_io_wq = alloc_workqueue("nvmet-buffered-io-wq",
 			WQ_MEM_RECLAIM, 0);
 	if (!buffered_io_wq) {
 		error = -ENOMEM;
-		goto out;
+		goto out_passthru_destroy;
 	}
 
 	error = nvmet_init_discovery();
@@ -1482,6 +1488,8 @@ static int __init nvmet_init(void)
 	nvmet_exit_discovery();
 out_free_work_queue:
 	destroy_workqueue(buffered_io_wq);
+out_passthru_destroy:
+	nvmet_passthru_destroy();
 out:
 	return error;
 }
@@ -1492,6 +1500,7 @@ static void __exit nvmet_exit(void)
 	nvmet_exit_discovery();
 	ida_destroy(&cntlid_ida);
 	destroy_workqueue(buffered_io_wq);
+	nvmet_passthru_destroy();
 
 	BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
 	BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);
diff --git a/drivers/nvme/target/io-cmd-passthru.c b/drivers/nvme/target/io-cmd-passthru.c
new file mode 100644
index 000000000000..46c58fec5608
--- /dev/null
+++ b/drivers/nvme/target/io-cmd-passthru.c
@@ -0,0 +1,572 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVMe Over Fabrics Target Passthrough command implementation.
+ *
+ * Copyright (c) 2017-2018 Western Digital Corporation or its
+ * affiliates.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+
+#include "../host/nvme.h"
+#include "nvmet.h"
+
+static struct workqueue_struct *passthru_wq;
+
+int nvmet_passthru_init(void)
+{
+	passthru_wq = alloc_workqueue("nvmet-passthru-wq", WQ_MEM_RECLAIM, 0);
+	if (!passthru_wq)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void nvmet_passthru_destroy(void)
+{
+	destroy_workqueue(passthru_wq);
+}
+
+static void nvmet_passthru_req_complete(struct nvmet_req *req,
+		struct request *rq, u16 status)
+{
+	nvmet_req_complete(req, status);
+
+	if (rq)
+		blk_put_request(rq);
+}
+
+static void nvmet_passthru_req_done(struct request *rq,
+		blk_status_t blk_status)
+{
+	struct nvmet_req *req = rq->end_io_data;
+	u16 status = nvme_req(rq)->status;
+
+	req->cqe->result.u32 = nvme_req(rq)->result.u32;
+
+	nvmet_passthru_req_complete(req, rq, status);
+}
+
+static u16 nvmet_passthru_override_format_nvm(struct nvmet_req *req)
+{
+	int lbaf = le32_to_cpu(req->cmd->format.cdw10) & 0x0000000F;
+	int nsid = le32_to_cpu(req->cmd->format.nsid);
+	u16 status = NVME_SC_SUCCESS;
+	struct nvme_id_ns *id;
+
+	id = nvme_identify_ns(nvmet_req_passthru_ctrl(req), nsid);
+	if (!id)
+		return NVME_SC_INTERNAL;
+	/*
+	 * XXX: Please update this code once NVMeOF target starts supporting
+	 * metadata. We don't support ns lba format with metadata over fabrics
+	 * right now, so report an error if format nvm cmd tries to format
+	 * a namespace with the LBA format which has metadata.
+	 */
+	if (id->lbaf[lbaf].ms)
+		status = NVME_SC_INVALID_NS;
+
+	kfree(id);
+	return status;
+}
+
+static void nvmet_passthru_set_mdts(struct nvmet_ctrl *ctrl,
+				    struct nvme_id_ctrl *id)
+{
+	struct nvme_ctrl *pctrl = ctrl->subsys->passthru_ctrl;
+	u32 max_hw_sectors;
+	int page_shift;
+
+	/*
+	 * The passthru NVMe driver may have a limit on the number
+	 * of segments which depends on the host's memory fragementation.
+	 * To solve this, ensure mdts is limitted to the pages equal to
+	 * the number of segments.
+	 */
+
+	max_hw_sectors = min_not_zero(pctrl->max_segments << (PAGE_SHIFT - 9),
+				      pctrl->max_hw_sectors);
+
+	page_shift = NVME_CAP_MPSMIN(ctrl->cap) + 12;
+
+	id->mdts = ilog2(max_hw_sectors) + 9 - page_shift;
+}
+
+static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
+{
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	u16 status = NVME_SC_SUCCESS;
+	struct nvme_id_ctrl *id;
+
+	id = kzalloc(sizeof(*id), GFP_KERNEL);
+	if (!id) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+	status = nvmet_copy_from_sgl(req, 0, id, sizeof(*id));
+	if (status)
+		goto out_free;
+
+	id->cntlid = cpu_to_le16(ctrl->cntlid);
+	id->ver = cpu_to_le32(ctrl->subsys->ver);
+
+	nvmet_passthru_set_mdts(ctrl, id);
+
+	id->acl = 3;
+	/*
+	 * We export aerl limit for the fabrics controller, update this when
+	 * passthru based aerl support is added.
+	 */
+	id->aerl = NVMET_ASYNC_EVENTS - 1;
+
+	/* emulate kas as most of the PCIe ctrl don't have a support for kas */
+	id->kas = cpu_to_le16(NVMET_KAS);
+
+	/* don't support host memory buffer */
+	id->hmpre = 0;
+	id->hmmin = 0;
+
+	id->sqes = min_t(__u8, ((0x6 << 4) | 0x6), id->sqes);
+	id->cqes = min_t(__u8, ((0x4 << 4) | 0x4), id->cqes);
+	id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
+
+	/* don't support fuse commands */
+	id->fuses = 0;
+
+	id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */
+	if (ctrl->ops->has_keyed_sgls)
+		id->sgls |= cpu_to_le32(1 << 2);
+	if (req->port->inline_data_size)
+		id->sgls |= cpu_to_le32(1 << 20);
+
+	/*
+	 * When passsthru controller is setup using nvme-loop transport it will
+	 * export the passthru ctrl subsysnqn (PCIe NVMe ctrl) and will fail in
+	 * the nvme/host/core.c in the nvme_init_subsystem()->nvme_active_ctrl()
+	 * code path with duplicate ctr subsynqn. In order to prevent that we
+	 * mask the passthru-ctrl subsysnqn with the target ctrl subsysnqn.
+	 */
+	memcpy(id->subnqn, ctrl->subsysnqn, sizeof(id->subnqn));
+
+	/* use fabric id-ctrl values */
+	id->ioccsz = cpu_to_le32((sizeof(struct nvme_command) +
+				req->port->inline_data_size) / 16);
+	id->iorcsz = cpu_to_le32(sizeof(struct nvme_completion) / 16);
+
+	id->msdbd = ctrl->ops->msdbd;
+
+	/* Support multipath connections with fabrics */
+	id->cmic |= 1 << 1;
+
+	status = nvmet_copy_to_sgl(req, 0, id, sizeof(struct nvme_id_ctrl));
+
+out_free:
+	kfree(id);
+out:
+	return status;
+}
+
+static u16 nvmet_passthru_override_id_ns(struct nvmet_req *req)
+{
+	u16 status = NVME_SC_SUCCESS;
+	struct nvme_id_ns *id;
+	int i;
+
+	id = kzalloc(sizeof(*id), GFP_KERNEL);
+	if (!id) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+
+	status = nvmet_copy_from_sgl(req, 0, id, sizeof(struct nvme_id_ns));
+	if (status)
+		goto out_free;
+
+	for (i = 0; i < (id->nlbaf + 1); i++)
+		if (id->lbaf[i].ms)
+			memset(&id->lbaf[i], 0, sizeof(id->lbaf[i]));
+
+	id->flbas = id->flbas & ~(1 << 4);
+	id->mc = 0;
+
+	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
+
+out_free:
+	kfree(id);
+out:
+	return status;
+}
+
+static u16 nvmet_passthru_fixup_identify(struct nvmet_req *req)
+{
+	u16 status = NVME_SC_SUCCESS;
+
+	switch (req->cmd->identify.cns) {
+	case NVME_ID_CNS_CTRL:
+		status = nvmet_passthru_override_id_ctrl(req);
+		break;
+	case NVME_ID_CNS_NS:
+		status = nvmet_passthru_override_id_ns(req);
+		break;
+	}
+	return status;
+}
+
+static u16 nvmet_passthru_admin_passthru_start(struct nvmet_req *req)
+{
+	u16 status = NVME_SC_SUCCESS;
+
+	switch (req->cmd->common.opcode) {
+	case nvme_admin_format_nvm:
+		status = nvmet_passthru_override_format_nvm(req);
+		break;
+	}
+	return status;
+}
+
+static u16 nvmet_passthru_admin_passthru_end(struct nvmet_req *req)
+{
+	u8 aer_type = NVME_AER_TYPE_NOTICE;
+	u16 status = NVME_SC_SUCCESS;
+
+	switch (req->cmd->common.opcode) {
+	case nvme_admin_identify:
+		status = nvmet_passthru_fixup_identify(req);
+		break;
+	case nvme_admin_ns_mgmt:
+	case nvme_admin_ns_attach:
+	case nvme_admin_format_nvm:
+		if (!nvmet_add_async_event(req->sq->ctrl, aer_type, 0, 0))
+			status = NVME_SC_INTERNAL;
+		break;
+	}
+	return status;
+}
+
+static void nvmet_passthru_execute_admin_cmd(struct nvmet_req *req)
+{
+	u8 opcode = req->cmd->common.opcode;
+	u32 effects;
+	u16 status;
+
+	status = nvmet_passthru_admin_passthru_start(req);
+	if (status)
+		goto out;
+
+	effects = nvme_passthru_start(nvmet_req_passthru_ctrl(req), NULL,
+				      opcode);
+
+	/*
+	 * Admin Commands have side effects and it is better to handle those
+	 * side effects in the submission thread context than in the request
+	 * completion path, which is in the interrupt context. Also in this
+	 * way, we keep the passhru admin command code path consistent with the
+	 * nvme/host/core.c sync command submission APIs/IOCTLs and use
+	 * nvme_passthru_start/end() to handle side effects consistently.
+	 */
+	blk_execute_rq(req->p.rq->q, NULL, req->p.rq, 0);
+
+	nvme_passthru_end(nvmet_req_passthru_ctrl(req), effects);
+	status = nvmet_passthru_admin_passthru_end(req);
+out:
+	if (status == NVME_SC_SUCCESS) {
+		nvmet_set_result(req, nvme_req(req->p.rq)->result.u32);
+		status = nvme_req(req->p.rq)->status;
+	}
+
+	nvmet_passthru_req_complete(req, req->p.rq, status);
+}
+
+static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq)
+{
+	int sg_cnt = req->sg_cnt;
+	struct scatterlist *sg;
+	int op = REQ_OP_READ;
+	int op_flags = 0;
+	struct bio *bio;
+	int i, ret;
+
+	if (nvme_is_write(req->cmd)) {
+		op = REQ_OP_WRITE;
+		op_flags = REQ_SYNC | REQ_IDLE;
+	}
+
+	bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
+	bio->bi_end_io = bio_put;
+
+	for_each_sg(req->sg, sg, req->sg_cnt, i) {
+		if (bio_add_page(bio, sg_page(sg), sg->length,
+				 sg->offset) != sg->length) {
+			ret = blk_rq_append_bio(rq, &bio);
+			if (unlikely(ret))
+				return ret;
+
+			bio_set_op_attrs(bio, op, op_flags);
+			bio = bio_alloc(GFP_KERNEL,
+					min(sg_cnt, BIO_MAX_PAGES));
+		}
+		sg_cnt--;
+	}
+
+	ret = blk_rq_append_bio(rq, &bio);
+	if (unlikely(ret))
+		return ret;
+
+	return 0;
+}
+
+static struct request *nvmet_passthru_blk_make_request(struct nvmet_req *req,
+		struct nvme_ns *ns, gfp_t gfp_mask)
+{
+	struct nvme_ctrl *passthru_ctrl = nvmet_req_passthru_ctrl(req);
+	struct nvme_command *cmd = req->cmd;
+	struct request_queue *q;
+	struct request *rq;
+	int ret;
+
+	if (ns)
+		q = ns->queue;
+	else
+		q = passthru_ctrl->admin_q;
+
+	rq = nvme_alloc_request(q, cmd, BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
+	if (unlikely(IS_ERR(rq)))
+		return rq;
+
+	if (req->sg_cnt) {
+		ret = nvmet_passthru_map_sg(req, rq);
+		if (unlikely(ret)) {
+			blk_put_request(rq);
+			return ERR_PTR(ret);
+		}
+	}
+
+	/*
+	 * We don't support fused cmds, also nvme-pci driver uses its own
+	 * sgl_threshold parameter to decide whether to use SGLs or PRPs hence
+	 * turn off those bits in the flags.
+	 */
+	req->cmd->common.flags &= ~(NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND |
+			NVME_CMD_SGL_ALL);
+	return rq;
+}
+
+
+static void nvmet_passthru_execute_admin_work(struct work_struct *w)
+{
+	struct nvmet_req *req = container_of(w, struct nvmet_req, p.work);
+
+	nvmet_passthru_execute_admin_cmd(req);
+}
+
+static void nvmet_passthru_submit_admin_cmd(struct nvmet_req *req)
+{
+	INIT_WORK(&req->p.work, nvmet_passthru_execute_admin_work);
+	queue_work(passthru_wq, &req->p.work);
+}
+
+static void nvmet_passthru_execute_cmd(struct nvmet_req *req)
+{
+	struct request *rq = NULL;
+	struct nvme_ns *ns = NULL;
+	u16 status;
+
+	if (likely(req->sq->qid != 0)) {
+		u32 nsid = le32_to_cpu(req->cmd->common.nsid);
+
+		ns = nvme_find_get_ns(nvmet_req_passthru_ctrl(req), nsid);
+		if (unlikely(!ns)) {
+			pr_err("failed to get passthru ns nsid:%u\n", nsid);
+			status = NVME_SC_INVALID_NS | NVME_SC_DNR;
+			goto fail_out;
+		}
+	}
+
+	rq = nvmet_passthru_blk_make_request(req, ns, GFP_KERNEL);
+	if (unlikely(IS_ERR(rq))) {
+		rq = NULL;
+		status = NVME_SC_INTERNAL;
+		goto fail_out;
+	}
+
+	if (unlikely(blk_rq_nr_phys_segments(rq) > queue_max_segments(rq->q) ||
+	    (blk_rq_payload_bytes(rq) >> 9) > queue_max_hw_sectors(rq->q))) {
+		status = NVME_SC_INVALID_FIELD;
+		goto fail_out;
+	}
+
+	rq->end_io_data = req;
+	if (req->sq->qid != 0) {
+		blk_execute_rq_nowait(rq->q, NULL, rq, 0,
+				      nvmet_passthru_req_done);
+	} else {
+		req->p.rq = rq;
+		nvmet_passthru_submit_admin_cmd(req);
+	}
+
+	if (ns)
+		nvme_put_ns(ns);
+
+	return;
+
+fail_out:
+	if (ns)
+		nvme_put_ns(ns);
+	nvmet_passthru_req_complete(req, rq, status);
+}
+
+/*
+ * We emulate commands which are not routed through the existing target
+ * code and not supported by the passthru ctrl. E.g consider a scenario where
+ * passthru ctrl version is < 1.3.0. Target Fabrics ctrl version is >= 1.3.0
+ * in that case in order to be fabrics compliant we need to emulate ns-desc-list
+ * command which is 1.3.0 compliant but not present for the passthru ctrl due
+ * to lower version.
+ */
+static void nvmet_passthru_emulate_id_desclist(struct nvmet_req *req)
+{
+	int nsid = le32_to_cpu(req->cmd->common.nsid);
+	u16 status = NVME_SC_SUCCESS;
+	struct nvme_ns_ids *ids;
+	struct nvme_ns *ns;
+	off_t off = 0;
+
+	ns = nvme_find_get_ns(nvmet_req_passthru_ctrl(req), nsid);
+	if (unlikely(!ns)) {
+		pr_err("failed to get passthru ns nsid:%u\n", nsid);
+		status = NVME_SC_INVALID_NS | NVME_SC_DNR;
+		goto out;
+	}
+	/*
+	 * Instead of refactoring and creating helpers, keep it simple and
+	 * just re-use the code from admin-cmd.c ->
+	 * nvmet_execute_identify_ns_desclist().
+	 */
+	ids = &ns->head->ids;
+	if (memchr_inv(ids->eui64, 0, sizeof(ids->eui64))) {
+		status = nvmet_copy_ns_identifier(req, NVME_NIDT_EUI64,
+						  NVME_NIDT_EUI64_LEN,
+						  &ids->eui64, &off);
+		if (status)
+			goto out_put_ns;
+	}
+	if (memchr_inv(&ids->uuid, 0, sizeof(ids->uuid))) {
+		status = nvmet_copy_ns_identifier(req, NVME_NIDT_UUID,
+						  NVME_NIDT_UUID_LEN,
+						  &ids->uuid, &off);
+		if (status)
+			goto out_put_ns;
+	}
+	if (memchr_inv(ids->nguid, 0, sizeof(ids->nguid))) {
+		status = nvmet_copy_ns_identifier(req, NVME_NIDT_NGUID,
+						  NVME_NIDT_NGUID_LEN,
+						  &ids->nguid, &off);
+		if (status)
+			goto out_put_ns;
+	}
+
+	if (sg_zero_buffer(req->sg, req->sg_cnt, NVME_IDENTIFY_DATA_SIZE - off,
+			off) != NVME_IDENTIFY_DATA_SIZE - off)
+		status = NVME_SC_INTERNAL | NVME_SC_DNR;
+out_put_ns:
+	nvme_put_ns(ns);
+out:
+	nvmet_req_complete(req, status);
+}
+
+/*
+ * In the passthru mode we support three types for commands:-
+ * 1. Commands which are black-listed.
+ * 2. Commands which are routed through target code.
+ * 3. Commands which are emulated in the target code, since we can't rely
+ *    on passthru-ctrl and cannot route through the target code.
+ */
+static u16 nvmet_parse_passthru_admin_cmd(struct nvmet_req *req)
+{
+	struct nvme_command *cmd = req->cmd;
+	u16 status = 0;
+
+	switch (cmd->common.opcode) {
+	/* 1. commands which are blacklisted */
+	case nvme_admin_create_sq:
+	case nvme_admin_create_cq:
+	case nvme_admin_delete_sq:
+	case nvme_admin_delete_cq:
+	case nvme_admin_activate_fw:
+	case nvme_admin_download_fw:
+	case nvme_admin_ns_attach:
+	case nvme_admin_directive_send:
+	case nvme_admin_directive_recv:
+	case nvme_admin_dbbuf:
+	case nvme_admin_security_send:
+	case nvme_admin_security_recv:
+		status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+		req->execute = NULL;
+		break;
+	/* 2. commands which are routed through target code */
+	case nvme_admin_async_event:
+	/*
+	 * Right now we don't monitor any events for the passthru controller.
+	 * Instead generate asyn event notice for the ns-mgmt/format/attach
+	 * commands so that host can update it's ns-inventory.
+	 */
+		/* fallthru */
+	case nvme_admin_keep_alive:
+	/*
+	 * Most PCIe ctrls don't support keep alive cmd, we route keep alive
+	 * to the non-passthru mode. In future please change this code when
+	 * PCIe ctrls with keep alive support available.
+	 */
+		status = nvmet_parse_admin_cmd(req);
+		break;
+	case nvme_admin_set_features:
+		switch (le32_to_cpu(req->cmd->features.fid)) {
+		case NVME_FEAT_ASYNC_EVENT:
+		case NVME_FEAT_KATO:
+		case NVME_FEAT_NUM_QUEUES:
+			status = nvmet_parse_admin_cmd(req);
+			break;
+		default:
+			req->execute = nvmet_passthru_execute_cmd;
+		}
+		break;
+	/* 3. commands which are emulated in the passthru code */
+	case nvme_admin_identify:
+		switch (req->cmd->identify.cns) {
+		case NVME_ID_CNS_NS_DESC_LIST:
+			req->execute = nvmet_passthru_emulate_id_desclist;
+			break;
+		default:
+			req->execute = nvmet_passthru_execute_cmd;
+		}
+		break;
+	default:
+		/*
+		 * We passthru all the remaining commands, including
+		 * Vendor-Unique Commands
+		 */
+		req->execute = nvmet_passthru_execute_cmd;
+	}
+
+	return status;
+}
+
+u16 nvmet_parse_passthru_cmd(struct nvmet_req *req)
+{
+	int ret;
+
+	if (unlikely(req->cmd->common.opcode == nvme_fabrics_command))
+		return nvmet_parse_fabrics_cmd(req);
+	else if (unlikely(req->sq->ctrl->subsys->type == NVME_NQN_DISC))
+		return nvmet_parse_discovery_cmd(req);
+
+	ret = nvmet_check_ctrl_status(req, req->cmd);
+	if (unlikely(ret))
+		return ret;
+
+	if (unlikely(req->sq->qid == 0))
+		return nvmet_parse_passthru_admin_cmd(req);
+
+	req->execute = nvmet_passthru_execute_cmd;
+	return NVME_SC_SUCCESS;
+}
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index d1a0a3190a24..bd11114ebbb9 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -227,6 +227,10 @@ struct nvmet_subsys {
 
 	struct config_group	namespaces_group;
 	struct config_group	allowed_hosts_group;
+
+#ifdef CONFIG_NVME_TARGET_PASSTHRU
+	struct nvme_ctrl	*passthru_ctrl;
+#endif /* CONFIG_NVME_TARGET_PASSTHRU */
 };
 
 static inline struct nvmet_subsys *to_subsys(struct config_item *item)
@@ -302,6 +306,10 @@ struct nvmet_req {
 			struct bio_vec          *bvec;
 			struct work_struct      work;
 		} f;
+		struct {
+			struct request		*rq;
+			struct work_struct      work;
+		} p;
 	};
 	int			sg_cnt;
 	/* data length as parsed from the command: */
@@ -497,6 +505,44 @@ static inline u32 nvmet_rw_len(struct nvmet_req *req)
 			req->ns->blksize_shift;
 }
 
+#ifdef CONFIG_NVME_TARGET_PASSTHRU
+
+int nvmet_passthru_init(void);
+void nvmet_passthru_destroy(void);
+u16 nvmet_parse_passthru_cmd(struct nvmet_req *req);
+
+static inline
+struct nvme_ctrl *nvmet_passthru_ctrl(struct nvmet_subsys *subsys)
+{
+	return subsys->passthru_ctrl;
+}
+
+#else /* CONFIG_NVME_TARGET_PASSTHRU */
+
+static inline int nvmet_passthru_init(void)
+{
+	return 0;
+}
+static inline void nvmet_passthru_destroy(void)
+{
+}
+static inline u16 nvmet_parse_passthru_cmd(struct nvmet_req *req)
+{
+	return 0;
+}
+static inline
+struct nvme_ctrl *nvmet_passthru_ctrl(struct nvmet_subsys *subsys)
+{
+	return NULL;
+}
+
+#endif /* CONFIG_NVME_TARGET_PASSTHRU */
+
+static inline struct nvme_ctrl *nvmet_req_passthru_ctrl(struct nvmet_req *req)
+{
+	return nvmet_passthru_ctrl(req->sq->ctrl->subsys);
+}
+
 u16 errno_to_nvme_status(struct nvmet_req *req, int errno);
 
 /* Convert a 32-bit number to a 16-bit 0's based number */
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (5 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 06/14] nvmet-passthru: add passthru code to process commands Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-15 12:20   ` Max Gurtovoy
  2019-08-01 23:45 ` [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl Logan Gunthorpe
                   ` (6 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe,
	Chaitanya Kulkarni

This patch adds helper functions which are used in the NVMeOF configfs
when the user is configuring the passthru subsystem. Here we ensure
that only one subsys is assigned to each nvme_ctrl by using an xarray
on the cntlid.

[chaitanya.kulkarni@wdc.com: this patch is very roughly based
 on a similar one by Chaitanya]
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/core.c            |  8 +++
 drivers/nvme/target/io-cmd-passthru.c | 77 +++++++++++++++++++++++++++
 drivers/nvme/target/nvmet.h           | 10 ++++
 3 files changed, 95 insertions(+)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 50c01b2da568..2e75968af7f4 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -519,6 +519,12 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
 
 	mutex_lock(&subsys->lock);
 	ret = 0;
+
+	if (nvmet_passthru_ctrl(subsys)) {
+		pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
+		goto out_unlock;
+	}
+
 	if (ns->enabled)
 		goto out_unlock;
 
@@ -1439,6 +1445,8 @@ static void nvmet_subsys_free(struct kref *ref)
 
 	WARN_ON_ONCE(!list_empty(&subsys->namespaces));
 
+	nvmet_passthru_subsys_free(subsys);
+
 	kfree(subsys->subsysnqn);
 	kfree(subsys);
 }
diff --git a/drivers/nvme/target/io-cmd-passthru.c b/drivers/nvme/target/io-cmd-passthru.c
index 46c58fec5608..b199785500ad 100644
--- a/drivers/nvme/target/io-cmd-passthru.c
+++ b/drivers/nvme/target/io-cmd-passthru.c
@@ -11,6 +11,11 @@
 #include "../host/nvme.h"
 #include "nvmet.h"
 
+/*
+ * xarray to maintain one passthru subsystem per nvme controller.
+ */
+static DEFINE_XARRAY(passthru_subsystems);
+
 static struct workqueue_struct *passthru_wq;
 
 int nvmet_passthru_init(void)
@@ -27,6 +32,78 @@ void nvmet_passthru_destroy(void)
 	destroy_workqueue(passthru_wq);
 }
 
+int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys)
+{
+	struct nvme_ctrl *ctrl;
+	int ret = -EINVAL;
+	void *old;
+
+	mutex_lock(&subsys->lock);
+	if (!subsys->passthru_ctrl_path)
+		goto out_unlock;
+	if (subsys->passthru_ctrl)
+		goto out_unlock;
+
+	if (subsys->nr_namespaces) {
+		pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
+		goto out_unlock;
+	}
+
+	ctrl = nvme_ctrl_get_by_path(subsys->passthru_ctrl_path);
+	if (IS_ERR(ctrl)) {
+		ret = PTR_ERR(ctrl);
+		pr_err("failed to open nvme controller %s\n",
+		       subsys->passthru_ctrl_path);
+
+		goto out_unlock;
+	}
+
+	old = xa_cmpxchg(&passthru_subsystems, ctrl->cntlid, NULL,
+			 subsys, GFP_KERNEL);
+	if (xa_is_err(old)) {
+		ret = xa_err(old);
+		goto out_put_ctrl;
+	}
+
+	if (old)
+		goto out_put_ctrl;
+
+	subsys->passthru_ctrl = ctrl;
+	ret = 0;
+
+	goto out_unlock;
+
+out_put_ctrl:
+	nvme_put_ctrl(ctrl);
+out_unlock:
+	mutex_unlock(&subsys->lock);
+	return ret;
+}
+
+static void __nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
+{
+	if (subsys->passthru_ctrl) {
+		xa_erase(&passthru_subsystems, subsys->passthru_ctrl->cntlid);
+		nvme_put_ctrl(subsys->passthru_ctrl);
+	}
+	subsys->passthru_ctrl = NULL;
+}
+
+void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
+{
+	mutex_lock(&subsys->lock);
+	__nvmet_passthru_ctrl_disable(subsys);
+	mutex_unlock(&subsys->lock);
+}
+
+void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
+{
+	mutex_lock(&subsys->lock);
+	__nvmet_passthru_ctrl_disable(subsys);
+	kfree(subsys->passthru_ctrl_path);
+	mutex_unlock(&subsys->lock);
+}
+
 static void nvmet_passthru_req_complete(struct nvmet_req *req,
 		struct request *rq, u16 status)
 {
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index bd11114ebbb9..aff4db03269d 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -230,6 +230,7 @@ struct nvmet_subsys {
 
 #ifdef CONFIG_NVME_TARGET_PASSTHRU
 	struct nvme_ctrl	*passthru_ctrl;
+	char			*passthru_ctrl_path;
 #endif /* CONFIG_NVME_TARGET_PASSTHRU */
 };
 
@@ -509,6 +510,9 @@ static inline u32 nvmet_rw_len(struct nvmet_req *req)
 
 int nvmet_passthru_init(void);
 void nvmet_passthru_destroy(void);
+void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys);
+int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys);
+void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys);
 u16 nvmet_parse_passthru_cmd(struct nvmet_req *req);
 
 static inline
@@ -526,6 +530,12 @@ static inline int nvmet_passthru_init(void)
 static inline void nvmet_passthru_destroy(void)
 {
 }
+static inline void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
+{
+}
+static inline void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
+{
+}
 static inline u16 nvmet_parse_passthru_cmd(struct nvmet_req *req)
 {
 	return 0;
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (6 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-15 12:36   ` Max Gurtovoy
  2019-08-01 23:45 ` [PATCH v7 09/14] nvmet-core: don't check the data len for pt-ctrl Logan Gunthorpe
                   ` (5 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe,
	Chaitanya Kulkarni

This patch rejects any new connection to the passthru-ctrl if this
controller is already connected to a different host. At the time of
allocating the controller we check if the subsys associated with
the passthru ctrl is already connected to a host and reject it
if the hostnqn differs.

Connections from the same host (by hostnqn) are supported to allow
for multipath.

[chaitanya.kulkarni@wdc.com: based conceptually on a similar patch but
  different implementation]
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/core.c            |  4 ++++
 drivers/nvme/target/io-cmd-passthru.c | 31 +++++++++++++++++++++++++++
 drivers/nvme/target/nvmet.h           |  7 ++++++
 3 files changed, 42 insertions(+)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 2e75968af7f4..c655f26db3da 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -1278,6 +1278,10 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
 	if (!ctrl->sqs)
 		goto out_free_cqs;
 
+	ret = nvmet_passthru_alloc_ctrl(subsys, hostnqn);
+	if (ret)
+		goto out_free_sqs;
+
 	ret = ida_simple_get(&cntlid_ida,
 			     NVME_CNTLID_MIN, NVME_CNTLID_MAX,
 			     GFP_KERNEL);
diff --git a/drivers/nvme/target/io-cmd-passthru.c b/drivers/nvme/target/io-cmd-passthru.c
index b199785500ad..06a919283cc5 100644
--- a/drivers/nvme/target/io-cmd-passthru.c
+++ b/drivers/nvme/target/io-cmd-passthru.c
@@ -104,6 +104,37 @@ void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
 	mutex_unlock(&subsys->lock);
 }
 
+int nvmet_passthru_alloc_ctrl(struct nvmet_subsys *subsys,
+			      const char *hostnqn)
+{
+	struct nvmet_ctrl *ctrl;
+
+	/*
+	 * Check here if this subsystem is already connected to the passthru
+	 * ctrl. We allow only one host to connect to a given passthru
+	 * subsystem.
+	 */
+	int rc = 0;
+
+	mutex_lock(&subsys->lock);
+
+	if (!subsys->passthru_ctrl)
+		goto out;
+
+	if (list_empty(&subsys->ctrls))
+		goto out;
+
+	ctrl = list_first_entry(&subsys->ctrls, struct nvmet_ctrl,
+				subsys_entry);
+
+	if (strcmp(hostnqn, ctrl->hostnqn))
+		rc = -ENODEV;
+
+out:
+	mutex_unlock(&subsys->lock);
+	return rc;
+}
+
 static void nvmet_passthru_req_complete(struct nvmet_req *req,
 		struct request *rq, u16 status)
 {
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index aff4db03269d..6436cb990905 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -513,6 +513,8 @@ void nvmet_passthru_destroy(void);
 void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys);
 int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys);
 void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys);
+int nvmet_passthru_alloc_ctrl(struct nvmet_subsys *subsys,
+			      const char *hostnqn);
 u16 nvmet_parse_passthru_cmd(struct nvmet_req *req);
 
 static inline
@@ -536,6 +538,11 @@ static inline void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
 static inline void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
 {
 }
+static inline int nvmet_passthru_alloc_ctrl(struct nvmet_subsys *subsys,
+					    const char *hostnqn)
+{
+	return 0;
+}
 static inline u16 nvmet_parse_passthru_cmd(struct nvmet_req *req)
 {
 	return 0;
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 09/14] nvmet-core: don't check the data len for pt-ctrl
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (7 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 10/14] nvmet-tcp: don't check data_len in nvmet_tcp_map_data() Logan Gunthorpe
                   ` (4 subsequent siblings)
  13 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates,
	Chaitanya Kulkarni, Logan Gunthorpe

From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

Right now, data_len is calculated before the transfer len after we
parse the command, With passthru interface we allow VUCs (Vendor-Unique
Commands). In order to make the code simple and compact, instead of
assigning the data len or each VUC in the command parse function
just use the transfer len as it is. This may result in error if expected
data_len != transfer_len.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[logang@deltatee.com:
   * added definition of VUC to the commit message and comment
   * use nvmet_req_passthru_ctrl() helper seeing we can't dereference
     subsys->passthru_ctrl if CONFIG_NVME_TARGET_PASSTHRU is not set]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/core.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index c655f26db3da..1cda94437fbf 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -941,7 +941,16 @@ EXPORT_SYMBOL_GPL(nvmet_req_uninit);
 
 void nvmet_req_execute(struct nvmet_req *req)
 {
-	if (unlikely(req->data_len != req->transfer_len)) {
+	/*
+	 * data_len is calculated before the transfer len after we parse
+	 * the command, With passthru interface we allow VUC (Vendor-Unique
+	 * Commands)'s. In order to make the code simple and compact,
+	 * instead of assinging the dala len for each VUC in the command
+	 * parse function just use the transfer len as it is. This may
+	 * result in error if expected data_len != transfer_len.
+	 */
+	if (!(req->sq->ctrl && nvmet_req_passthru_ctrl(req)) &&
+	    unlikely(req->data_len != req->transfer_len)) {
 		req->error_loc = offsetof(struct nvme_common_command, dptr);
 		nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
 	} else
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 10/14] nvmet-tcp: don't check data_len in nvmet_tcp_map_data()
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (8 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 09/14] nvmet-core: don't check the data len for pt-ctrl Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 11/14] nvmet-configfs: introduce passthru configfs interface Logan Gunthorpe
                   ` (3 subsequent siblings)
  13 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe

With passthru, the data_len is no longer guaranteed to be set
for all requests. Therefore, we should not check for it to be
non-zero. Instead check if the SGL length is zero and map
when appropriate.

None of the other transports check data_len which is verified
in core code.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/tcp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 69b83fa0c76c..db5bc5f444c4 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -320,7 +320,7 @@ static int nvmet_tcp_map_data(struct nvmet_tcp_cmd *cmd)
 	struct nvme_sgl_desc *sgl = &cmd->req.cmd->common.dptr.sgl;
 	u32 len = le32_to_cpu(sgl->length);
 
-	if (!cmd->req.data_len)
+	if (!len)
 		return 0;
 
 	if (sgl->type == ((NVME_SGL_FMT_DATA_DESC << 4) |
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 11/14] nvmet-configfs: introduce passthru configfs interface
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (9 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 10/14] nvmet-tcp: don't check data_len in nvmet_tcp_map_data() Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-15 12:46   ` Max Gurtovoy
  2019-08-01 23:45 ` [PATCH v7 12/14] block: don't check blk_rq_is_passthrough() in blk_do_io_stat() Logan Gunthorpe
                   ` (2 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe

When CONFIG_NVME_TARGET_PASSTHRU as 'passthru' directory will
be added to each subsystem. The directory is similar to a namespace
and has two attributes: device_path and enable. The user must set the
path to the nvme controller's char device and write '1' to enable the
subsystem to use passthru.

Any given subsystem is prevented from enabling both a regular namespace
and the passthru device. If one is enabled, enabling the other will
produce an error.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/configfs.c | 99 ++++++++++++++++++++++++++++++++++
 drivers/nvme/target/nvmet.h    |  1 +
 2 files changed, 100 insertions(+)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 98613a45bd3b..b15d64c19f58 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -615,6 +615,103 @@ static const struct config_item_type nvmet_namespaces_type = {
 	.ct_owner		= THIS_MODULE,
 };
 
+#ifdef CONFIG_NVME_TARGET_PASSTHRU
+
+static ssize_t nvmet_passthru_device_path_show(struct config_item *item,
+		char *page)
+{
+	struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
+
+	return snprintf(page, PAGE_SIZE, "%s\n", subsys->passthru_ctrl_path);
+}
+
+static ssize_t nvmet_passthru_device_path_store(struct config_item *item,
+		const char *page, size_t count)
+{
+	struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
+	int ret = -ENOMEM;
+	size_t len;
+
+	mutex_lock(&subsys->lock);
+
+	ret = -EBUSY;
+	if (subsys->passthru_ctrl)
+		goto out_unlock;
+
+	ret = -EINVAL;
+	len = strcspn(page, "\n");
+	if (!len)
+		goto out_unlock;
+
+	kfree(subsys->passthru_ctrl_path);
+	ret = -ENOMEM;
+	subsys->passthru_ctrl_path = kstrndup(page, len, GFP_KERNEL);
+	if (!subsys->passthru_ctrl_path)
+		goto out_unlock;
+
+	mutex_unlock(&subsys->lock);
+
+	return count;
+out_unlock:
+	mutex_unlock(&subsys->lock);
+	return ret;
+}
+CONFIGFS_ATTR(nvmet_passthru_, device_path);
+
+static ssize_t nvmet_passthru_enable_show(struct config_item *item,
+		char *page)
+{
+	struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
+
+	return sprintf(page, "%d\n", subsys->passthru_ctrl ? 1 : 0);
+}
+
+static ssize_t nvmet_passthru_enable_store(struct config_item *item,
+		const char *page, size_t count)
+{
+	struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
+	bool enable;
+	int ret = 0;
+
+	if (strtobool(page, &enable))
+		return -EINVAL;
+
+	if (enable)
+		ret = nvmet_passthru_ctrl_enable(subsys);
+	else
+		nvmet_passthru_ctrl_disable(subsys);
+
+	return ret ? ret : count;
+}
+CONFIGFS_ATTR(nvmet_passthru_, enable);
+
+static struct configfs_attribute *nvmet_passthru_attrs[] = {
+	&nvmet_passthru_attr_device_path,
+	&nvmet_passthru_attr_enable,
+	NULL,
+};
+
+static const struct config_item_type nvmet_passthru_type = {
+	.ct_attrs		= nvmet_passthru_attrs,
+	.ct_owner		= THIS_MODULE,
+};
+
+static void nvmet_add_passthru_group(struct nvmet_subsys *subsys)
+{
+	config_group_init_type_name(&subsys->passthru_group,
+				    "passthru", &nvmet_passthru_type);
+	configfs_add_default_group(&subsys->passthru_group,
+				   &subsys->group);
+}
+
+#else /* CONFIG_NVME_TARGET_PASSTHRU */
+
+static void nvmet_add_passthru_group(struct nvmet_subsys *subsys)
+{
+}
+
+#endif /* CONFIG_NVME_TARGET_PASSTHRU */
+
 static int nvmet_port_subsys_allow_link(struct config_item *parent,
 		struct config_item *target)
 {
@@ -915,6 +1012,8 @@ static struct config_group *nvmet_subsys_make(struct config_group *group,
 	configfs_add_default_group(&subsys->allowed_hosts_group,
 			&subsys->group);
 
+	nvmet_add_passthru_group(subsys);
+
 	return &subsys->group;
 }
 
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 6436cb990905..f9c593f1305d 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -231,6 +231,7 @@ struct nvmet_subsys {
 #ifdef CONFIG_NVME_TARGET_PASSTHRU
 	struct nvme_ctrl	*passthru_ctrl;
 	char			*passthru_ctrl_path;
+	struct config_group	passthru_group;
 #endif /* CONFIG_NVME_TARGET_PASSTHRU */
 };
 
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 12/14] block: don't check blk_rq_is_passthrough() in blk_do_io_stat()
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (10 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 11/14] nvmet-configfs: introduce passthru configfs interface Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 13/14] block: call blk_account_io_start() in blk_execute_rq_nowait() Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 14/14] nvmet-passthru: support block accounting Logan Gunthorpe
  13 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe

Instead of checking blk_rq_is_passthruough() for every call to
blk_do_io_stat(), don't set RQF_IO_STAT for passthrough requests.
This should be equivalent, and opens the possibility of passthrough
requests specifically requesting statistics tracking.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 block/blk-mq.c | 2 +-
 block/blk.h    | 5 ++---
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index f78d3287dd82..66cb5bfa2ebf 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -318,7 +318,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 	rq->cmd_flags = op;
 	if (data->flags & BLK_MQ_REQ_PREEMPT)
 		rq->rq_flags |= RQF_PREEMPT;
-	if (blk_queue_io_stat(data->q))
+	if (blk_queue_io_stat(data->q) && !blk_rq_is_passthrough(rq))
 		rq->rq_flags |= RQF_IO_STAT;
 	INIT_LIST_HEAD(&rq->queuelist);
 	INIT_HLIST_NODE(&rq->hash);
diff --git a/block/blk.h b/block/blk.h
index de6b2e146d6e..554efa769bfe 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -234,13 +234,12 @@ int blk_dev_init(void);
  *
  *	a) it's attached to a gendisk, and
  *	b) the queue had IO stats enabled when this request was started, and
- *	c) it's a file system request
+ *	c) it's a file system request (RQF_IO_STAT will not be set otherwise)
  */
 static inline bool blk_do_io_stat(struct request *rq)
 {
 	return rq->rq_disk &&
-	       (rq->rq_flags & RQF_IO_STAT) &&
-		!blk_rq_is_passthrough(rq);
+	       (rq->rq_flags & RQF_IO_STAT);
 }
 
 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 13/14] block: call blk_account_io_start() in blk_execute_rq_nowait()
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (11 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 12/14] block: don't check blk_rq_is_passthrough() in blk_do_io_stat() Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  2019-08-01 23:45 ` [PATCH v7 14/14] nvmet-passthru: support block accounting Logan Gunthorpe
  13 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe

All existing users of blk_execute_rq[_nowait]() are for passthrough
commands and will thus be rejected by blk_do_io_stat().

This allows passthrough requests to opt-in to IO accounting by setting
RQF_IO_STAT.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 block/blk-exec.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block/blk-exec.c b/block/blk-exec.c
index 1db44ca0f4a6..e20a852ae432 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -55,6 +55,8 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 	rq->rq_disk = bd_disk;
 	rq->end_io = done;
 
+	blk_account_io_start(rq, true);
+
 	/*
 	 * don't check dying flag for MQ because the request won't
 	 * be reused after dying flag is set
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* [PATCH v7 14/14] nvmet-passthru: support block accounting
  2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
                   ` (12 preceding siblings ...)
  2019-08-01 23:45 ` [PATCH v7 13/14] block: call blk_account_io_start() in blk_execute_rq_nowait() Logan Gunthorpe
@ 2019-08-01 23:45 ` Logan Gunthorpe
  13 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-01 23:45 UTC (permalink / raw)
  To: linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Max Gurtovoy, Stephen Bates, Logan Gunthorpe

Support block disk accounting by setting the RQF_IO_STAT flag
and gendisk in the request.

After this change, IO counts will be reflected correctly in
/proc/diskstats for drives being used by passthru.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/target/io-cmd-passthru.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/io-cmd-passthru.c b/drivers/nvme/target/io-cmd-passthru.c
index 06a919283cc5..cb193b434545 100644
--- a/drivers/nvme/target/io-cmd-passthru.c
+++ b/drivers/nvme/target/io-cmd-passthru.c
@@ -441,6 +441,9 @@ static struct request *nvmet_passthru_blk_make_request(struct nvmet_req *req,
 	if (unlikely(IS_ERR(rq)))
 		return rq;
 
+	if (blk_queue_io_stat(q) && cmd->common.opcode != nvme_cmd_flush)
+		rq->rq_flags |= RQF_IO_STAT;
+
 	if (req->sg_cnt) {
 		ret = nvmet_passthru_map_sg(req, rq);
 		if (unlikely(ret)) {
@@ -505,7 +508,7 @@ static void nvmet_passthru_execute_cmd(struct nvmet_req *req)
 
 	rq->end_io_data = req;
 	if (req->sq->qid != 0) {
-		blk_execute_rq_nowait(rq->q, NULL, rq, 0,
+		blk_execute_rq_nowait(rq->q, ns->disk, rq, 0,
 				      nvmet_passthru_req_done);
 	} else {
 		req->p.rq = rq;
-- 
2.20.1


^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path()
  2019-08-01 23:45 ` [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path() Logan Gunthorpe
@ 2019-08-14 14:20   ` Max Gurtovoy
  2019-08-15 11:46   ` Max Gurtovoy
  1 sibling, 0 replies; 29+ messages in thread
From: Max Gurtovoy @ 2019-08-14 14:20 UTC (permalink / raw)
  To: Logan Gunthorpe, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates


On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> nvme_ctrl_get_by_path() is analagous to blkdev_get_by_path() except it
> gets a struct nvme_ctrl from the path to its char dev (/dev/nvme0).
> It makes use of filp_open() to open the file and uses the private
> data to obtain a pointer to the struct nvme_ctrl. If the fops of the
> file do not match, -EINVAL is returned.
>
> The purpose of this function is to support NVMe-OF target passthru.
>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> ---
>   drivers/nvme/host/core.c | 24 ++++++++++++++++++++++++
>   drivers/nvme/host/nvme.h |  2 ++
>   2 files changed, 26 insertions(+)


Looks good,

Reviewed-by: Max Gurtovoy <maxg@mellanox.com>



^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 03/14] nvmet: add return value to nvmet_add_async_event()
  2019-08-01 23:45 ` [PATCH v7 03/14] nvmet: add return value to nvmet_add_async_event() Logan Gunthorpe
@ 2019-08-14 14:26   ` Max Gurtovoy
  2019-08-14 16:59     ` Logan Gunthorpe
  0 siblings, 1 reply; 29+ messages in thread
From: Max Gurtovoy @ 2019-08-14 14:26 UTC (permalink / raw)
  To: Logan Gunthorpe, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates


On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
>
> Change the return value for nvmet_add_async_event().
>
> This change is needed for the target passthru code to generate async
> events.

As a stand alone commit it's not clear what is the purpose of it.

Please add some extra explanation in the commit message.

Also better to use integer as return value if the return value should 
reflect return code.


> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> [logang@deltatee.com: fixed up commit message that was no
>   longer accurate]
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> ---
>   drivers/nvme/target/core.c  | 5 +++--
>   drivers/nvme/target/nvmet.h | 2 +-
>   2 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
> index 3a67e244e568..f7f25bdc4763 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -173,14 +173,14 @@ static void nvmet_async_event_work(struct work_struct *work)
>   	}
>   }
>   
> -void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
> +bool nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
>   		u8 event_info, u8 log_page)
>   {
>   	struct nvmet_async_event *aen;
>   
>   	aen = kmalloc(sizeof(*aen), GFP_KERNEL);
>   	if (!aen)
> -		return;
> +		return false;
>   
>   	aen->event_type = event_type;
>   	aen->event_info = event_info;
> @@ -191,6 +191,7 @@ void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
>   	mutex_unlock(&ctrl->lock);
>   
>   	schedule_work(&ctrl->async_event_work);
> +	return true;
>   }
>   
>   static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index c51f8dd01dc4..217a787952e8 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -441,7 +441,7 @@ void nvmet_port_disc_changed(struct nvmet_port *port,
>   		struct nvmet_subsys *subsys);
>   void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
>   		struct nvmet_host *host);
> -void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
> +bool nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
>   		u8 event_info, u8 log_page);
>   
>   #define NVMET_QUEUE_SIZE	1024

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 04/14] nvmet: make nvmet_copy_ns_identifier() non-static
  2019-08-01 23:45 ` [PATCH v7 04/14] nvmet: make nvmet_copy_ns_identifier() non-static Logan Gunthorpe
@ 2019-08-14 14:29   ` Max Gurtovoy
  2019-08-15  7:15     ` Chaitanya Kulkarni
  0 siblings, 1 reply; 29+ messages in thread
From: Max Gurtovoy @ 2019-08-14 14:29 UTC (permalink / raw)
  To: Logan Gunthorpe, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates


On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> This function will be needed by the upcoming passthru code.

Same here. As a standalone commit I can't take a lot from here.

Maybe should be squashed ?


>
> [chaitanya.kulkarni@wdc.com: this was factored out of a patch
>   originally authored by Chaitanya]
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> ---
>   drivers/nvme/target/admin-cmd.c | 4 ++--
>   drivers/nvme/target/nvmet.h     | 2 ++
>   2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
> index 4dc12ea52f23..eeb24f606d00 100644
> --- a/drivers/nvme/target/admin-cmd.c
> +++ b/drivers/nvme/target/admin-cmd.c
> @@ -506,8 +506,8 @@ static void nvmet_execute_identify_nslist(struct nvmet_req *req)
>   	nvmet_req_complete(req, status);
>   }
>   
> -static u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
> -				    void *id, off_t *off)
> +u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
> +			     void *id, off_t *off)
>   {
>   	struct nvme_ns_id_desc desc = {
>   		.nidt = type,
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index 217a787952e8..d1a0a3190a24 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -489,6 +489,8 @@ u16 nvmet_bdev_flush(struct nvmet_req *req);
>   u16 nvmet_file_flush(struct nvmet_req *req);
>   void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid);
>   
> +u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
> +			     void *id, off_t *off);
>   static inline u32 nvmet_rw_len(struct nvmet_req *req)
>   {
>   	return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 05/14] nvmet-passthru: update KConfig with config passthru option
  2019-08-01 23:45 ` [PATCH v7 05/14] nvmet-passthru: update KConfig with config passthru option Logan Gunthorpe
@ 2019-08-14 14:31   ` Max Gurtovoy
  0 siblings, 0 replies; 29+ messages in thread
From: Max Gurtovoy @ 2019-08-14 14:31 UTC (permalink / raw)
  To: Logan Gunthorpe, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates


On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
>
> This patch updates KConfig file for the NVMeOF target where we add new
> option so that user can selectively enable/disable passthru code.
>
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> [logang@deltatee.com: fixed some of the wording in the help message]
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> ---
>   drivers/nvme/target/Kconfig | 10 ++++++++++
>   1 file changed, 10 insertions(+)
>
> diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
> index d7f48c0fb311..2478cb5a932d 100644
> --- a/drivers/nvme/target/Kconfig
> +++ b/drivers/nvme/target/Kconfig
> @@ -15,6 +15,16 @@ config NVME_TARGET
>   	  To configure the NVMe target you probably want to use the nvmetcli
>   	  tool from http://git.infradead.org/users/hch/nvmetcli.git.
>   
> +config NVME_TARGET_PASSTHRU
> +	bool "NVMe Target Passthrough support"
> +	depends on NVME_CORE
> +	depends on NVME_TARGET
> +	help
> +	  This enables target side NVMe passthru controller support for the
> +	  NVMe Over Fabrics protocol. It allows for hosts to manage and
> +	  directly access an actual NVMe controller residing on the target
> +	  side, incuding executing Vendor Unique Commands.
> +
>   config NVME_TARGET_LOOP
>   	tristate "NVMe loopback device support"
>   	depends on NVME_TARGET


Looks good,

Reviewed-by: Max Gurtovoy <maxg@mellanox.com>



^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 03/14] nvmet: add return value to nvmet_add_async_event()
  2019-08-14 14:26   ` Max Gurtovoy
@ 2019-08-14 16:59     ` Logan Gunthorpe
  0 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-14 16:59 UTC (permalink / raw)
  To: Max Gurtovoy, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates



On 2019-08-14 8:26 a.m., Max Gurtovoy wrote:
> 
> On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
>> From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
>>
>> Change the return value for nvmet_add_async_event().
>>
>> This change is needed for the target passthru code to generate async
>> events.
> 
> As a stand alone commit it's not clear what is the purpose of it.
> 
> Please add some extra explanation in the commit message.
> 
> Also better to use integer as return value if the return value should
> reflect return code.

Thanks for the Review, Max. I'll queue up these changes for v8.

Logan

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 04/14] nvmet: make nvmet_copy_ns_identifier() non-static
  2019-08-14 14:29   ` Max Gurtovoy
@ 2019-08-15  7:15     ` Chaitanya Kulkarni
  0 siblings, 0 replies; 29+ messages in thread
From: Chaitanya Kulkarni @ 2019-08-15  7:15 UTC (permalink / raw)
  To: Max Gurtovoy, Logan Gunthorpe, linux-kernel, linux-nvme,
	linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe, Stephen Bates

On 8/14/19 7:30 AM, Max Gurtovoy wrote:
> 
> On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
>> This function will be needed by the upcoming passthru code.
> 
> Same here. As a standalone commit I can't take a lot from here.
> 
> Maybe should be squashed ?

This commit changes the existing code which is independent of the
passthru code which we are adding. For that reason I've made this
standalone as it doesn't have direct modification from w.r.t passthru 
code.

Perhaps more documentation will make this clear.

> 
> 
>>
>> [chaitanya.kulkarni@wdc.com: this was factored out of a patch
>>    originally authored by Chaitanya]
>> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
>> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
>> ---
>>    drivers/nvme/target/admin-cmd.c | 4 ++--
>>    drivers/nvme/target/nvmet.h     | 2 ++
>>    2 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
>> index 4dc12ea52f23..eeb24f606d00 100644
>> --- a/drivers/nvme/target/admin-cmd.c
>> +++ b/drivers/nvme/target/admin-cmd.c
>> @@ -506,8 +506,8 @@ static void nvmet_execute_identify_nslist(struct nvmet_req *req)
>>    	nvmet_req_complete(req, status);
>>    }
>>    
>> -static u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
>> -				    void *id, off_t *off)
>> +u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
>> +			     void *id, off_t *off)
>>    {
>>    	struct nvme_ns_id_desc desc = {
>>    		.nidt = type,
>> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
>> index 217a787952e8..d1a0a3190a24 100644
>> --- a/drivers/nvme/target/nvmet.h
>> +++ b/drivers/nvme/target/nvmet.h
>> @@ -489,6 +489,8 @@ u16 nvmet_bdev_flush(struct nvmet_req *req);
>>    u16 nvmet_file_flush(struct nvmet_req *req);
>>    void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid);
>>    
>> +u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
>> +			     void *id, off_t *off);
>>    static inline u32 nvmet_rw_len(struct nvmet_req *req)
>>    {
>>    	return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<
> 


^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path()
  2019-08-01 23:45 ` [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path() Logan Gunthorpe
  2019-08-14 14:20   ` Max Gurtovoy
@ 2019-08-15 11:46   ` Max Gurtovoy
  2019-08-15 15:59     ` Logan Gunthorpe
  1 sibling, 1 reply; 29+ messages in thread
From: Max Gurtovoy @ 2019-08-15 11:46 UTC (permalink / raw)
  To: Logan Gunthorpe, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates


On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> nvme_ctrl_get_by_path() is analagous to blkdev_get_by_path() except it
> gets a struct nvme_ctrl from the path to its char dev (/dev/nvme0).
> It makes use of filp_open() to open the file and uses the private
> data to obtain a pointer to the struct nvme_ctrl. If the fops of the
> file do not match, -EINVAL is returned.
>
> The purpose of this function is to support NVMe-OF target passthru.
>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> ---
>   drivers/nvme/host/core.c | 24 ++++++++++++++++++++++++
>   drivers/nvme/host/nvme.h |  2 ++
>   2 files changed, 26 insertions(+)
>
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index e6ee6f2a3da6..f72334f34a30 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2817,6 +2817,30 @@ static const struct file_operations nvme_dev_fops = {
>   	.compat_ioctl	= nvme_dev_ioctl,
>   };
>   
> +struct nvme_ctrl *nvme_ctrl_get_by_path(const char *path)
> +{
> +	struct nvme_ctrl *ctrl;
> +	struct file *f;
> +
> +	f = filp_open(path, O_RDWR, 0);
> +	if (IS_ERR(f))
> +		return ERR_CAST(f);
> +
> +	if (f->f_op != &nvme_dev_fops) {
> +		ctrl = ERR_PTR(-EINVAL);
> +		goto out_close;
> +	}

Logan,

this means that the PT is for nvme-pci and also nvme-fabrics as well.

Is this the intention ? or we want to restrict it to pci only.



> +
> +	ctrl = f->private_data;
> +	nvme_get_ctrl(ctrl);
> +
> +out_close:
> +	filp_close(f, NULL);
> +
> +	return ctrl;
> +}
> +EXPORT_SYMBOL_GPL(nvme_ctrl_get_by_path);
> +
>   static ssize_t nvme_sysfs_reset(struct device *dev,
>   				struct device_attribute *attr, const char *buf,
>   				size_t count)
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index ecbd90c31d0d..7e827c9e892c 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -484,6 +484,8 @@ int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp,
>   extern const struct attribute_group *nvme_ns_id_attr_groups[];
>   extern const struct block_device_operations nvme_ns_head_ops;
>   
> +struct nvme_ctrl *nvme_ctrl_get_by_path(const char *path);
> +
>   #ifdef CONFIG_NVME_MULTIPATH
>   static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
>   {

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers
  2019-08-01 23:45 ` [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers Logan Gunthorpe
@ 2019-08-15 12:20   ` Max Gurtovoy
  2019-08-15 16:02     ` Logan Gunthorpe
  0 siblings, 1 reply; 29+ messages in thread
From: Max Gurtovoy @ 2019-08-15 12:20 UTC (permalink / raw)
  To: Logan Gunthorpe, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates


On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> This patch adds helper functions which are used in the NVMeOF configfs
> when the user is configuring the passthru subsystem. Here we ensure
> that only one subsys is assigned to each nvme_ctrl by using an xarray
> on the cntlid.
>
> [chaitanya.kulkarni@wdc.com: this patch is very roughly based
>   on a similar one by Chaitanya]
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> ---
>   drivers/nvme/target/core.c            |  8 +++
>   drivers/nvme/target/io-cmd-passthru.c | 77 +++++++++++++++++++++++++++
>   drivers/nvme/target/nvmet.h           | 10 ++++
>   3 files changed, 95 insertions(+)
>
> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
> index 50c01b2da568..2e75968af7f4 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -519,6 +519,12 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
>   
>   	mutex_lock(&subsys->lock);
>   	ret = 0;
> +
> +	if (nvmet_passthru_ctrl(subsys)) {
> +		pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
> +		goto out_unlock;
> +	}
> +
>   	if (ns->enabled)
>   		goto out_unlock;
>   
> @@ -1439,6 +1445,8 @@ static void nvmet_subsys_free(struct kref *ref)
>   
>   	WARN_ON_ONCE(!list_empty(&subsys->namespaces));
>   
> +	nvmet_passthru_subsys_free(subsys);
> +
>   	kfree(subsys->subsysnqn);
>   	kfree(subsys);
>   }
> diff --git a/drivers/nvme/target/io-cmd-passthru.c b/drivers/nvme/target/io-cmd-passthru.c
> index 46c58fec5608..b199785500ad 100644
> --- a/drivers/nvme/target/io-cmd-passthru.c
> +++ b/drivers/nvme/target/io-cmd-passthru.c
> @@ -11,6 +11,11 @@
>   #include "../host/nvme.h"
>   #include "nvmet.h"
>   
> +/*
> + * xarray to maintain one passthru subsystem per nvme controller.
> + */
> +static DEFINE_XARRAY(passthru_subsystems);
> +
>   static struct workqueue_struct *passthru_wq;
>   
>   int nvmet_passthru_init(void)
> @@ -27,6 +32,78 @@ void nvmet_passthru_destroy(void)
>   	destroy_workqueue(passthru_wq);
>   }
>   
> +int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys)
> +{
> +	struct nvme_ctrl *ctrl;
> +	int ret = -EINVAL;
> +	void *old;
> +
> +	mutex_lock(&subsys->lock);
> +	if (!subsys->passthru_ctrl_path)
> +		goto out_unlock;
> +	if (subsys->passthru_ctrl)
> +		goto out_unlock;
> +
> +	if (subsys->nr_namespaces) {
> +		pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
> +		goto out_unlock;
> +	}
> +
> +	ctrl = nvme_ctrl_get_by_path(subsys->passthru_ctrl_path);
> +	if (IS_ERR(ctrl)) {
> +		ret = PTR_ERR(ctrl);
> +		pr_err("failed to open nvme controller %s\n",
> +		       subsys->passthru_ctrl_path);
> +
> +		goto out_unlock;
> +	}
> +
> +	old = xa_cmpxchg(&passthru_subsystems, ctrl->cntlid, NULL,
> +			 subsys, GFP_KERNEL);
> +	if (xa_is_err(old)) {
> +		ret = xa_err(old);
> +		goto out_put_ctrl;
> +	}
> +
> +	if (old)
> +		goto out_put_ctrl;
> +
> +	subsys->passthru_ctrl = ctrl;
> +	ret = 0;
> +
> +	goto out_unlock;

can we re-arrange the code here ?

it's not so common to see goto in a good flow.

maybe have 1 good flow the goto's will go bellow it as we usually do in 
this subsystem.


> +
> +out_put_ctrl:
> +	nvme_put_ctrl(ctrl);
> +out_unlock:
> +	mutex_unlock(&subsys->lock);
> +	return ret;
> +}
> +
> +static void __nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
> +{
> +	if (subsys->passthru_ctrl) {
> +		xa_erase(&passthru_subsystems, subsys->passthru_ctrl->cntlid);
> +		nvme_put_ctrl(subsys->passthru_ctrl);
> +	}
> +	subsys->passthru_ctrl = NULL;
> +}
> +
> +void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
> +{
> +	mutex_lock(&subsys->lock);
> +	__nvmet_passthru_ctrl_disable(subsys);
> +	mutex_unlock(&subsys->lock);
> +}
> +
> +void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
> +{
> +	mutex_lock(&subsys->lock);
> +	__nvmet_passthru_ctrl_disable(subsys);
> +	kfree(subsys->passthru_ctrl_path);
> +	mutex_unlock(&subsys->lock);
> +}
> +
>   static void nvmet_passthru_req_complete(struct nvmet_req *req,
>   		struct request *rq, u16 status)
>   {
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index bd11114ebbb9..aff4db03269d 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -230,6 +230,7 @@ struct nvmet_subsys {
>   
>   #ifdef CONFIG_NVME_TARGET_PASSTHRU
>   	struct nvme_ctrl	*passthru_ctrl;
> +	char			*passthru_ctrl_path;
>   #endif /* CONFIG_NVME_TARGET_PASSTHRU */
>   };
>   
> @@ -509,6 +510,9 @@ static inline u32 nvmet_rw_len(struct nvmet_req *req)
>   
>   int nvmet_passthru_init(void);
>   void nvmet_passthru_destroy(void);
> +void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys);
> +int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys);
> +void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys);
>   u16 nvmet_parse_passthru_cmd(struct nvmet_req *req);
>   
>   static inline
> @@ -526,6 +530,12 @@ static inline int nvmet_passthru_init(void)
>   static inline void nvmet_passthru_destroy(void)
>   {
>   }
> +static inline void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
> +{
> +}
> +static inline void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
> +{
> +}
>   static inline u16 nvmet_parse_passthru_cmd(struct nvmet_req *req)
>   {
>   	return 0;

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl
  2019-08-01 23:45 ` [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl Logan Gunthorpe
@ 2019-08-15 12:36   ` Max Gurtovoy
  2019-08-15 16:06     ` Logan Gunthorpe
  0 siblings, 1 reply; 29+ messages in thread
From: Max Gurtovoy @ 2019-08-15 12:36 UTC (permalink / raw)
  To: Logan Gunthorpe, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates


On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> This patch rejects any new connection to the passthru-ctrl if this
> controller is already connected to a different host. At the time of
> allocating the controller we check if the subsys associated with
> the passthru ctrl is already connected to a host and reject it
> if the hostnqn differs.

This is a big limitation.

Are we plan to enable many front-end ctrl's to connect to the single 
back-end ctrl in the future ?

I guess it can be incremental to this series.



^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 11/14] nvmet-configfs: introduce passthru configfs interface
  2019-08-01 23:45 ` [PATCH v7 11/14] nvmet-configfs: introduce passthru configfs interface Logan Gunthorpe
@ 2019-08-15 12:46   ` Max Gurtovoy
  0 siblings, 0 replies; 29+ messages in thread
From: Max Gurtovoy @ 2019-08-15 12:46 UTC (permalink / raw)
  To: Logan Gunthorpe, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates


On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> When CONFIG_NVME_TARGET_PASSTHRU as 'passthru' directory will
> be added to each subsystem. The directory is similar to a namespace
> and has two attributes: device_path and enable. The user must set the
> path to the nvme controller's char device and write '1' to enable the
> subsystem to use passthru.
>
> Any given subsystem is prevented from enabling both a regular namespace
> and the passthru device. If one is enabled, enabling the other will
> produce an error.
>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> ---
>   drivers/nvme/target/configfs.c | 99 ++++++++++++++++++++++++++++++++++
>   drivers/nvme/target/nvmet.h    |  1 +
>   2 files changed, 100 insertions(+)
>
> diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
> index 98613a45bd3b..b15d64c19f58 100644
> --- a/drivers/nvme/target/configfs.c
> +++ b/drivers/nvme/target/configfs.c
> @@ -615,6 +615,103 @@ static const struct config_item_type nvmet_namespaces_type = {
>   	.ct_owner		= THIS_MODULE,
>   };
>   
> +#ifdef CONFIG_NVME_TARGET_PASSTHRU
> +
> +static ssize_t nvmet_passthru_device_path_show(struct config_item *item,
> +		char *page)
> +{
> +	struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
> +
> +	return snprintf(page, PAGE_SIZE, "%s\n", subsys->passthru_ctrl_path);
> +}
> +
> +static ssize_t nvmet_passthru_device_path_store(struct config_item *item,
> +		const char *page, size_t count)
> +{
> +	struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
> +	int ret = -ENOMEM;

seems like a redundant initialization.

> +	size_t len;
> +
> +	mutex_lock(&subsys->lock);
> +
> +	ret = -EBUSY;
> +	if (subsys->passthru_ctrl)
> +		goto out_unlock;
> +
> +	ret = -EINVAL;
> +	len = strcspn(page, "\n");
> +	if (!len)
> +		goto out_unlock;
> +
> +	kfree(subsys->passthru_ctrl_path);
> +	ret = -ENOMEM;
> +	subsys->passthru_ctrl_path = kstrndup(page, len, GFP_KERNEL);
> +	if (!subsys->passthru_ctrl_path)
> +		goto out_unlock;
> +
> +	mutex_unlock(&subsys->lock);
> +
> +	return count;
> +out_unlock:
> +	mutex_unlock(&subsys->lock);
> +	return ret;
> +}
> +CONFIGFS_ATTR(nvmet_passthru_, device_path);
> +
> +static ssize_t nvmet_passthru_enable_show(struct config_item *item,
> +		char *page)
> +{
> +	struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
> +
> +	return sprintf(page, "%d\n", subsys->passthru_ctrl ? 1 : 0);
> +}
> +
> +static ssize_t nvmet_passthru_enable_store(struct config_item *item,
> +		const char *page, size_t count)
> +{
> +	struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
> +	bool enable;
> +	int ret = 0;
> +
> +	if (strtobool(page, &enable))
> +		return -EINVAL;
> +
> +	if (enable)
> +		ret = nvmet_passthru_ctrl_enable(subsys);
> +	else
> +		nvmet_passthru_ctrl_disable(subsys);
> +
> +	return ret ? ret : count;
> +}
> +CONFIGFS_ATTR(nvmet_passthru_, enable);
> +
> +static struct configfs_attribute *nvmet_passthru_attrs[] = {
> +	&nvmet_passthru_attr_device_path,
> +	&nvmet_passthru_attr_enable,
> +	NULL,
> +};
> +
> +static const struct config_item_type nvmet_passthru_type = {
> +	.ct_attrs		= nvmet_passthru_attrs,
> +	.ct_owner		= THIS_MODULE,
> +};
> +
> +static void nvmet_add_passthru_group(struct nvmet_subsys *subsys)
> +{
> +	config_group_init_type_name(&subsys->passthru_group,
> +				    "passthru", &nvmet_passthru_type);
> +	configfs_add_default_group(&subsys->passthru_group,
> +				   &subsys->group);
> +}
> +
> +#else /* CONFIG_NVME_TARGET_PASSTHRU */
> +
> +static void nvmet_add_passthru_group(struct nvmet_subsys *subsys)
> +{
> +}
> +
> +#endif /* CONFIG_NVME_TARGET_PASSTHRU */
> +
>   static int nvmet_port_subsys_allow_link(struct config_item *parent,
>   		struct config_item *target)
>   {
> @@ -915,6 +1012,8 @@ static struct config_group *nvmet_subsys_make(struct config_group *group,
>   	configfs_add_default_group(&subsys->allowed_hosts_group,
>   			&subsys->group);
>   
> +	nvmet_add_passthru_group(subsys);
> +
>   	return &subsys->group;
>   }
>   
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index 6436cb990905..f9c593f1305d 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -231,6 +231,7 @@ struct nvmet_subsys {
>   #ifdef CONFIG_NVME_TARGET_PASSTHRU
>   	struct nvme_ctrl	*passthru_ctrl;
>   	char			*passthru_ctrl_path;
> +	struct config_group	passthru_group;
>   #endif /* CONFIG_NVME_TARGET_PASSTHRU */
>   };
>   

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path()
  2019-08-15 11:46   ` Max Gurtovoy
@ 2019-08-15 15:59     ` Logan Gunthorpe
  0 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-15 15:59 UTC (permalink / raw)
  To: Max Gurtovoy, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates



On 2019-08-15 5:46 a.m., Max Gurtovoy wrote:
> 
> On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
>> nvme_ctrl_get_by_path() is analagous to blkdev_get_by_path() except it
>> gets a struct nvme_ctrl from the path to its char dev (/dev/nvme0).
>> It makes use of filp_open() to open the file and uses the private
>> data to obtain a pointer to the struct nvme_ctrl. If the fops of the
>> file do not match, -EINVAL is returned.
>>
>> The purpose of this function is to support NVMe-OF target passthru.
>>
>> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
>> ---
>>   drivers/nvme/host/core.c | 24 ++++++++++++++++++++++++
>>   drivers/nvme/host/nvme.h |  2 ++
>>   2 files changed, 26 insertions(+)
>>
>> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
>> index e6ee6f2a3da6..f72334f34a30 100644
>> --- a/drivers/nvme/host/core.c
>> +++ b/drivers/nvme/host/core.c
>> @@ -2817,6 +2817,30 @@ static const struct file_operations
>> nvme_dev_fops = {
>>       .compat_ioctl    = nvme_dev_ioctl,
>>   };
>>   +struct nvme_ctrl *nvme_ctrl_get_by_path(const char *path)
>> +{
>> +    struct nvme_ctrl *ctrl;
>> +    struct file *f;
>> +
>> +    f = filp_open(path, O_RDWR, 0);
>> +    if (IS_ERR(f))
>> +        return ERR_CAST(f);
>> +
>> +    if (f->f_op != &nvme_dev_fops) {
>> +        ctrl = ERR_PTR(-EINVAL);
>> +        goto out_close;
>> +    }
> 
> Logan,
> 
> this means that the PT is for nvme-pci and also nvme-fabrics as well.
> 
> Is this the intention ? or we want to restrict it to pci only.

Yes, in theory, someone could passthru an nvme-fabrics controller or
they could passthru a passthru'd passthru'd nvme-fabrics controller.
This probably isn't a good idea but I don't know that we need to
specifically reject it. If you think we should I could figure out a way
to filter by pci controllers only.

Logan

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers
  2019-08-15 12:20   ` Max Gurtovoy
@ 2019-08-15 16:02     ` Logan Gunthorpe
  0 siblings, 0 replies; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-15 16:02 UTC (permalink / raw)
  To: Max Gurtovoy, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates



On 2019-08-15 6:20 a.m., Max Gurtovoy wrote:
> 
> On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
>> This patch adds helper functions which are used in the NVMeOF configfs
>> when the user is configuring the passthru subsystem. Here we ensure
>> that only one subsys is assigned to each nvme_ctrl by using an xarray
>> on the cntlid.
>>
>> [chaitanya.kulkarni@wdc.com: this patch is very roughly based
>>   on a similar one by Chaitanya]
>> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
>> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
>> ---
>>   drivers/nvme/target/core.c            |  8 +++
>>   drivers/nvme/target/io-cmd-passthru.c | 77 +++++++++++++++++++++++++++
>>   drivers/nvme/target/nvmet.h           | 10 ++++
>>   3 files changed, 95 insertions(+)
>>
>> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
>> index 50c01b2da568..2e75968af7f4 100644
>> --- a/drivers/nvme/target/core.c
>> +++ b/drivers/nvme/target/core.c
>> @@ -519,6 +519,12 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
>>         mutex_lock(&subsys->lock);
>>       ret = 0;
>> +
>> +    if (nvmet_passthru_ctrl(subsys)) {
>> +        pr_info("cannot enable both passthru and regular namespaces
>> for a single subsystem");
>> +        goto out_unlock;
>> +    }
>> +
>>       if (ns->enabled)
>>           goto out_unlock;
>>   @@ -1439,6 +1445,8 @@ static void nvmet_subsys_free(struct kref *ref)
>>         WARN_ON_ONCE(!list_empty(&subsys->namespaces));
>>   +    nvmet_passthru_subsys_free(subsys);
>> +
>>       kfree(subsys->subsysnqn);
>>       kfree(subsys);
>>   }
>> diff --git a/drivers/nvme/target/io-cmd-passthru.c
>> b/drivers/nvme/target/io-cmd-passthru.c
>> index 46c58fec5608..b199785500ad 100644
>> --- a/drivers/nvme/target/io-cmd-passthru.c
>> +++ b/drivers/nvme/target/io-cmd-passthru.c
>> @@ -11,6 +11,11 @@
>>   #include "../host/nvme.h"
>>   #include "nvmet.h"
>>   +/*
>> + * xarray to maintain one passthru subsystem per nvme controller.
>> + */
>> +static DEFINE_XARRAY(passthru_subsystems);
>> +
>>   static struct workqueue_struct *passthru_wq;
>>     int nvmet_passthru_init(void)
>> @@ -27,6 +32,78 @@ void nvmet_passthru_destroy(void)
>>       destroy_workqueue(passthru_wq);
>>   }
>>   +int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys)
>> +{
>> +    struct nvme_ctrl *ctrl;
>> +    int ret = -EINVAL;
>> +    void *old;
>> +
>> +    mutex_lock(&subsys->lock);
>> +    if (!subsys->passthru_ctrl_path)
>> +        goto out_unlock;
>> +    if (subsys->passthru_ctrl)
>> +        goto out_unlock;
>> +
>> +    if (subsys->nr_namespaces) {
>> +        pr_info("cannot enable both passthru and regular namespaces
>> for a single subsystem");
>> +        goto out_unlock;
>> +    }
>> +
>> +    ctrl = nvme_ctrl_get_by_path(subsys->passthru_ctrl_path);
>> +    if (IS_ERR(ctrl)) {
>> +        ret = PTR_ERR(ctrl);
>> +        pr_err("failed to open nvme controller %s\n",
>> +               subsys->passthru_ctrl_path);
>> +
>> +        goto out_unlock;
>> +    }
>> +
>> +    old = xa_cmpxchg(&passthru_subsystems, ctrl->cntlid, NULL,
>> +             subsys, GFP_KERNEL);
>> +    if (xa_is_err(old)) {
>> +        ret = xa_err(old);
>> +        goto out_put_ctrl;
>> +    }
>> +
>> +    if (old)
>> +        goto out_put_ctrl;
>> +
>> +    subsys->passthru_ctrl = ctrl;
>> +    ret = 0;
>> +
>> +    goto out_unlock;
> 
> can we re-arrange the code here ?
> 
> it's not so common to see goto in a good flow.
> 
> maybe have 1 good flow the goto's will go bellow it as we usually do in
> this subsystem.

OK, queued up for v8.

Thanks,

Logan

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl
  2019-08-15 12:36   ` Max Gurtovoy
@ 2019-08-15 16:06     ` Logan Gunthorpe
  2019-08-18 10:33       ` Max Gurtovoy
  0 siblings, 1 reply; 29+ messages in thread
From: Logan Gunthorpe @ 2019-08-15 16:06 UTC (permalink / raw)
  To: Max Gurtovoy, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates



On 2019-08-15 6:36 a.m., Max Gurtovoy wrote:
> 
> On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
>> This patch rejects any new connection to the passthru-ctrl if this
>> controller is already connected to a different host. At the time of
>> allocating the controller we check if the subsys associated with
>> the passthru ctrl is already connected to a host and reject it
>> if the hostnqn differs.
> 
> This is a big limitation.
> 
> Are we plan to enable many front-end ctrl's to connect to the single
> back-end ctrl in the future ?

Honestly, I don't know that it's really necessary, but the limitation
was requested by Sagi the first time this patch-set was submitted[1]
citing unspecified user troubles. If there's consensus to remove the
restriction I certainly can.

Logan

[1] http://lists.infradead.org/pipermail/linux-nvme/2018-April/016588.html


^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl
  2019-08-15 16:06     ` Logan Gunthorpe
@ 2019-08-18 10:33       ` Max Gurtovoy
  0 siblings, 0 replies; 29+ messages in thread
From: Max Gurtovoy @ 2019-08-18 10:33 UTC (permalink / raw)
  To: Logan Gunthorpe, linux-kernel, linux-nvme, linux-block, linux-fsdevel
  Cc: Christoph Hellwig, Sagi Grimberg, Keith Busch, Jens Axboe,
	Chaitanya Kulkarni, Stephen Bates


On 8/15/2019 7:06 PM, Logan Gunthorpe wrote:
>
> On 2019-08-15 6:36 a.m., Max Gurtovoy wrote:
>> On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
>>> This patch rejects any new connection to the passthru-ctrl if this
>>> controller is already connected to a different host. At the time of
>>> allocating the controller we check if the subsys associated with
>>> the passthru ctrl is already connected to a host and reject it
>>> if the hostnqn differs.
>> This is a big limitation.
>>
>> Are we plan to enable many front-end ctrl's to connect to the single
>> back-end ctrl in the future ?
> Honestly, I don't know that it's really necessary, but the limitation
> was requested by Sagi the first time this patch-set was submitted[1]
> citing unspecified user troubles. If there's consensus to remove the
> restriction I certainly can.
>
> Logan
>
> [1] http://lists.infradead.org/pipermail/linux-nvme/2018-April/016588.html

I don't understand why we don't limit a regular ctrl to single access 
and we do it for the PT ctrl.

I guess the block layer helps to sync between multiple access in 
parallel but we can do it as well.

Also, let's say you limit the access to this subsystem to 1 user, the 
bdev is still accessibly for local user and also you can create a 
different subsystem that will use this device (PT and non-PT ctrl).

Sagi,

can you explain the trouble you meant and how this limitation solve it ?


^ permalink raw reply	[flat|nested] 29+ messages in thread

end of thread, back to index

Thread overview: 29+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path() Logan Gunthorpe
2019-08-14 14:20   ` Max Gurtovoy
2019-08-15 11:46   ` Max Gurtovoy
2019-08-15 15:59     ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 02/14] nvme-core: export existing ctrl and ns interfaces Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 03/14] nvmet: add return value to nvmet_add_async_event() Logan Gunthorpe
2019-08-14 14:26   ` Max Gurtovoy
2019-08-14 16:59     ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 04/14] nvmet: make nvmet_copy_ns_identifier() non-static Logan Gunthorpe
2019-08-14 14:29   ` Max Gurtovoy
2019-08-15  7:15     ` Chaitanya Kulkarni
2019-08-01 23:45 ` [PATCH v7 05/14] nvmet-passthru: update KConfig with config passthru option Logan Gunthorpe
2019-08-14 14:31   ` Max Gurtovoy
2019-08-01 23:45 ` [PATCH v7 06/14] nvmet-passthru: add passthru code to process commands Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers Logan Gunthorpe
2019-08-15 12:20   ` Max Gurtovoy
2019-08-15 16:02     ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl Logan Gunthorpe
2019-08-15 12:36   ` Max Gurtovoy
2019-08-15 16:06     ` Logan Gunthorpe
2019-08-18 10:33       ` Max Gurtovoy
2019-08-01 23:45 ` [PATCH v7 09/14] nvmet-core: don't check the data len for pt-ctrl Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 10/14] nvmet-tcp: don't check data_len in nvmet_tcp_map_data() Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 11/14] nvmet-configfs: introduce passthru configfs interface Logan Gunthorpe
2019-08-15 12:46   ` Max Gurtovoy
2019-08-01 23:45 ` [PATCH v7 12/14] block: don't check blk_rq_is_passthrough() in blk_do_io_stat() Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 13/14] block: call blk_account_io_start() in blk_execute_rq_nowait() Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 14/14] nvmet-passthru: support block accounting Logan Gunthorpe

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