Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

Pull SCSI target updates from Nicholas Bellinger:
 "It's been a busy development cycle for target-core in a number of
  different areas.

  The fabric API usage for se_node_acl allocation is now within
  target-core code, dropping the external API callers for all fabric
  drivers tree-wide.

  There is a new conversion to RCU hlists for se_node_acl and
  se_portal_group LUN mappings, that turns fast-past LUN lookup into a
  completely lockless code-path.  It also removes the original
  hard-coded limitation of 256 LUNs per fabric endpoint.

  The configfs attributes for backends can now be shared between core
  and driver code, allowing existing drivers to use common code while
  still allowing flexibility for new backend provided attributes.

  The highlights include:

   - Merge sbc_verify_dif_* into common code (sagi)
   - Remove iscsi-target support for obsolete IFMarker/OFMarker
     (Christophe Vu-Brugier)
   - Add bidi support in target/user backend (ilias + vangelis + agover)
   - Move se_node_acl allocation into target-core code (hch)
   - Add crc_t10dif_update common helper (akinobu + mkp)
   - Handle target-core odd SGL mapping for data transfer memory
     (akinobu)
   - Move transport ID handling into target-core (hch)
   - Move task tag into struct se_cmd + support 64-bit tags (bart)
   - Convert se_node_acl->device_list[] to RCU hlist (nab + hch +
     paulmck)
   - Convert se_portal_group->tpg_lun_list[] to RCU hlist (nab + hch +
     paulmck)
   - Simplify target backend driver registration (hch)
   - Consolidate + simplify target backend attribute implementations
     (hch + nab)
   - Subsume se_port + t10_alua_tg_pt_gp_member into se_lun (hch)
   - Drop lun_sep_lock for se_lun->lun_se_dev RCU usage (hch + nab)
   - Drop unnecessary core_tpg_register TFO parameter (nab)
   - Use 64-bit LUNs tree-wide (hannes)
   - Drop left-over TARGET_MAX_LUNS_PER_TRANSPORT limit (hannes)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (76 commits)
  target: Bump core version to v5.0
  target: remove target_core_configfs.h
  target: remove unused TARGET_CORE_CONFIG_ROOT define
  target: consolidate version defines
  target: implement WRITE_SAME with UNMAP bit using ->execute_unmap
  target: simplify UNMAP handling
  target: replace se_cmd->execute_rw with a protocol_data field
  target/user: Fix inconsistent kmap_atomic/kunmap_atomic
  target: Send UA when changing LUN inventory
  target: Send UA upon LUN RESET tmr completion
  target: Send UA on ALUA target port group change
  target: Convert se_lun->lun_deve_lock to normal spinlock
  target: use 'se_dev_entry' when allocating UAs
  target: Remove 'ua_nacl' pointer from se_ua structure
  target_core_alua: Correct UA handling when switching states
  xen-scsiback: Fix compile warning for 64-bit LUN
  target: Remove TARGET_MAX_LUNS_PER_TRANSPORT
  target: use 64-bit LUNs
  target: Drop duplicate + unused se_dev_check_wce
  target: Drop unnecessary core_tpg_register TFO parameter
  ...

1 files changed, 147 insertions, 119 deletions

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 549af9847c28..c448ef421ce7 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
  * Copyright (C) 2014 Red Hat, Inc.
+ * Copyright (C) 2015 Arrikto, Inc.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -30,7 +31,6 @@
 #include <target/target_core_base.h>
 #include <target/target_core_fabric.h>
 #include <target/target_core_backend.h>
-#include <target/target_core_backend_configfs.h>
 
 #include <linux/target_core_user.h>
 
@@ -168,6 +168,11 @@ static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
 	tcmu_cmd->tcmu_dev = udev;
 	tcmu_cmd->data_length = se_cmd->data_length;
 
+	if (se_cmd->se_cmd_flags & SCF_BIDI) {
+		BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
+		tcmu_cmd->data_length += se_cmd->t_bidi_data_sg->length;
+	}
+
 	tcmu_cmd->deadline = jiffies + msecs_to_jiffies(TCMU_TIME_OUT);
 
 	idr_preload(GFP_KERNEL);
@@ -226,9 +231,106 @@ static inline size_t head_to_end(size_t head, size_t size)
 
 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
 
+static void alloc_and_scatter_data_area(struct tcmu_dev *udev,
+	struct scatterlist *data_sg, unsigned int data_nents,
+	struct iovec **iov, int *iov_cnt, bool copy_data)
+{
+	int i;
+	void *from, *to;
+	size_t copy_bytes;
+	struct scatterlist *sg;
+
+	for_each_sg(data_sg, sg, data_nents, i) {
+		copy_bytes = min_t(size_t, sg->length,
+				 head_to_end(udev->data_head, udev->data_size));
+		from = kmap_atomic(sg_page(sg)) + sg->offset;
+		to = (void *) udev->mb_addr + udev->data_off + udev->data_head;
+
+		if (copy_data) {
+			memcpy(to, from, copy_bytes);
+			tcmu_flush_dcache_range(to, copy_bytes);
+		}
+
+		/* Even iov_base is relative to mb_addr */
+		(*iov)->iov_len = copy_bytes;
+		(*iov)->iov_base = (void __user *) udev->data_off +
+						udev->data_head;
+		(*iov_cnt)++;
+		(*iov)++;
+
+		UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size);
+
+		/* Uh oh, we wrapped the buffer. Must split sg across 2 iovs. */
+		if (sg->length != copy_bytes) {
+			void *from_skip = from + copy_bytes;
+
+			copy_bytes = sg->length - copy_bytes;
+
+			(*iov)->iov_len = copy_bytes;
+			(*iov)->iov_base = (void __user *) udev->data_off +
+							udev->data_head;
+
+			if (copy_data) {
+				to = (void *) udev->mb_addr +
+					udev->data_off + udev->data_head;
+				memcpy(to, from_skip, copy_bytes);
+				tcmu_flush_dcache_range(to, copy_bytes);
+			}
+
+			(*iov_cnt)++;
+			(*iov)++;
+
+			UPDATE_HEAD(udev->data_head,
+				copy_bytes, udev->data_size);
+		}
+
+		kunmap_atomic(from - sg->offset);
+	}
+}
+
+static void gather_and_free_data_area(struct tcmu_dev *udev,
+	struct scatterlist *data_sg, unsigned int data_nents)
+{
+	int i;
+	void *from, *to;
+	size_t copy_bytes;
+	struct scatterlist *sg;
+
+	/* It'd be easier to look at entry's iovec again, but UAM */
+	for_each_sg(data_sg, sg, data_nents, i) {
+		copy_bytes = min_t(size_t, sg->length,
+				 head_to_end(udev->data_tail, udev->data_size));
+
+		to = kmap_atomic(sg_page(sg)) + sg->offset;
+		WARN_ON(sg->length + sg->offset > PAGE_SIZE);
+		from = (void *) udev->mb_addr +
+			udev->data_off + udev->data_tail;
+		tcmu_flush_dcache_range(from, copy_bytes);
+		memcpy(to, from, copy_bytes);
+
+		UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
+
+		/* Uh oh, wrapped the data buffer for this sg's data */
+		if (sg->length != copy_bytes) {
+			void *to_skip = to + copy_bytes;
+
+			from = (void *) udev->mb_addr +
+				udev->data_off + udev->data_tail;
+			WARN_ON(udev->data_tail);
+			copy_bytes = sg->length - copy_bytes;
+			tcmu_flush_dcache_range(from, copy_bytes);
+			memcpy(to_skip, from, copy_bytes);
+
+			UPDATE_HEAD(udev->data_tail,
+				copy_bytes, udev->data_size);
+		}
+		kunmap_atomic(to - sg->offset);
+	}
+}
+
 /*
- * We can't queue a command until we have space available on the cmd ring *and* space
- * space avail on the data ring.
+ * We can't queue a command until we have space available on the cmd ring *and*
+ * space available on the data ring.
  *
  * Called with ring lock held.
  */
@@ -276,12 +378,11 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 	size_t base_command_size, command_size;
 	struct tcmu_mailbox *mb;
 	struct tcmu_cmd_entry *entry;
-	int i;
-	struct scatterlist *sg;
 	struct iovec *iov;
-	int iov_cnt = 0;
+	int iov_cnt;
 	uint32_t cmd_head;
 	uint64_t cdb_off;
+	bool copy_to_data_area;
 
 	if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
 		return -EINVAL;
@@ -294,7 +395,8 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 	 * b/c size == offsetof one-past-element.
 	*/
 	base_command_size = max(offsetof(struct tcmu_cmd_entry,
-					 req.iov[se_cmd->t_data_nents + 2]),
+					 req.iov[se_cmd->t_bidi_data_nents +
+						 se_cmd->t_data_nents + 2]),
 				sizeof(struct tcmu_cmd_entry));
 	command_size = base_command_size
 		+ round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE);
@@ -362,53 +464,20 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 	 * Fix up iovecs, and handle if allocation in data ring wrapped.
 	 */
 	iov = &entry->req.iov[0];
-	for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) {
-		size_t copy_bytes = min((size_t)sg->length,
-				     head_to_end(udev->data_head, udev->data_size));
-		void *from = kmap_atomic(sg_page(sg)) + sg->offset;
-		void *to = (void *) mb + udev->data_off + udev->data_head;
-
-		if (tcmu_cmd->se_cmd->data_direction == DMA_TO_DEVICE) {
-			memcpy(to, from, copy_bytes);
-			tcmu_flush_dcache_range(to, copy_bytes);
-		}
-
-		/* Even iov_base is relative to mb_addr */
-		iov->iov_len = copy_bytes;
-		iov->iov_base = (void __user *) udev->data_off +
-						udev->data_head;
-		iov_cnt++;
-		iov++;
-
-		UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size);
-
-		/* Uh oh, we wrapped the buffer. Must split sg across 2 iovs. */
-		if (sg->length != copy_bytes) {
-			from += copy_bytes;
-			copy_bytes = sg->length - copy_bytes;
-
-			iov->iov_len = copy_bytes;
-			iov->iov_base = (void __user *) udev->data_off +
-							udev->data_head;
-
-			if (se_cmd->data_direction == DMA_TO_DEVICE) {
-				to = (void *) mb + udev->data_off + udev->data_head;
-				memcpy(to, from, copy_bytes);
-				tcmu_flush_dcache_range(to, copy_bytes);
-			}
-
-			iov_cnt++;
-			iov++;
-
-			UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size);
-		}
-
-		kunmap_atomic(from);
-	}
+	iov_cnt = 0;
+	copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE
+		|| se_cmd->se_cmd_flags & SCF_BIDI);
+	alloc_and_scatter_data_area(udev, se_cmd->t_data_sg,
+		se_cmd->t_data_nents, &iov, &iov_cnt, copy_to_data_area);
 	entry->req.iov_cnt = iov_cnt;
-	entry->req.iov_bidi_cnt = 0;
 	entry->req.iov_dif_cnt = 0;
 
+	/* Handle BIDI commands */
+	iov_cnt = 0;
+	alloc_and_scatter_data_area(udev, se_cmd->t_bidi_data_sg,
+		se_cmd->t_bidi_data_nents, &iov, &iov_cnt, false);
+	entry->req.iov_bidi_cnt = iov_cnt;
+
 	/* All offsets relative to mb_addr, not start of entry! */
 	cdb_off = CMDR_OFF + cmd_head + base_command_size;
 	memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
@@ -481,47 +550,22 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *
 			       se_cmd->scsi_sense_length);
 
 		UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
-	}
-	else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
-		struct scatterlist *sg;
-		int i;
-
-		/* It'd be easier to look at entry's iovec again, but UAM */
-		for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) {
-			size_t copy_bytes;
-			void *to;
-			void *from;
-
-			copy_bytes = min((size_t)sg->length,
-					 head_to_end(udev->data_tail, udev->data_size));
-
-			to = kmap_atomic(sg_page(sg)) + sg->offset;
-			WARN_ON(sg->length + sg->offset > PAGE_SIZE);
-			from = (void *) udev->mb_addr + udev->data_off + udev->data_tail;
-			tcmu_flush_dcache_range(from, copy_bytes);
-			memcpy(to, from, copy_bytes);
-
-			UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
-
-			/* Uh oh, wrapped the data buffer for this sg's data */
-			if (sg->length != copy_bytes) {
-				from = (void *) udev->mb_addr + udev->data_off + udev->data_tail;
-				WARN_ON(udev->data_tail);
-				to += copy_bytes;
-				copy_bytes = sg->length - copy_bytes;
-				tcmu_flush_dcache_range(from, copy_bytes);
-				memcpy(to, from, copy_bytes);
-
-				UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
-			}
-
-			kunmap_atomic(to);
-		}
-
+	} else if (se_cmd->se_cmd_flags & SCF_BIDI) {
+		/* Discard data_out buffer */
+		UPDATE_HEAD(udev->data_tail,
+			(size_t)se_cmd->t_data_sg->length, udev->data_size);
+
+		/* Get Data-In buffer */
+		gather_and_free_data_area(udev,
+			se_cmd->t_bidi_data_sg, se_cmd->t_bidi_data_nents);
+	} else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
+		gather_and_free_data_area(udev,
+			se_cmd->t_data_sg, se_cmd->t_data_nents);
 	} else if (se_cmd->data_direction == DMA_TO_DEVICE) {
 		UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
-	} else {
-		pr_warn("TCMU: data direction was %d!\n", se_cmd->data_direction);
+	} else if (se_cmd->data_direction != DMA_NONE) {
+		pr_warn("TCMU: data direction was %d!\n",
+			se_cmd->data_direction);
 	}
 
 	target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
@@ -910,6 +954,14 @@ static int tcmu_check_pending_cmd(int id, void *p, void *data)
 	return -EINVAL;
 }
 
+static void tcmu_dev_call_rcu(struct rcu_head *p)
+{
+	struct se_device *dev = container_of(p, struct se_device, rcu_head);
+	struct tcmu_dev *udev = TCMU_DEV(dev);
+
+	kfree(udev);
+}
+
 static void tcmu_free_device(struct se_device *dev)
 {
 	struct tcmu_dev *udev = TCMU_DEV(dev);
@@ -935,8 +987,7 @@ static void tcmu_free_device(struct se_device *dev)
 		kfree(udev->uio_info.name);
 		kfree(udev->name);
 	}
-
-	kfree(udev);
+	call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
 }
 
 enum {
@@ -1054,27 +1105,7 @@ tcmu_parse_cdb(struct se_cmd *cmd)
 	return passthrough_parse_cdb(cmd, tcmu_pass_op);
 }
 
-DEF_TB_DEV_ATTRIB_RO(tcmu, hw_pi_prot_type);
-TB_DEV_ATTR_RO(tcmu, hw_pi_prot_type);
-
-DEF_TB_DEV_ATTRIB_RO(tcmu, hw_block_size);
-TB_DEV_ATTR_RO(tcmu, hw_block_size);
-
-DEF_TB_DEV_ATTRIB_RO(tcmu, hw_max_sectors);
-TB_DEV_ATTR_RO(tcmu, hw_max_sectors);
-
-DEF_TB_DEV_ATTRIB_RO(tcmu, hw_queue_depth);
-TB_DEV_ATTR_RO(tcmu, hw_queue_depth);
-
-static struct configfs_attribute *tcmu_backend_dev_attrs[] = {
-	&tcmu_dev_attrib_hw_pi_prot_type.attr,
-	&tcmu_dev_attrib_hw_block_size.attr,
-	&tcmu_dev_attrib_hw_max_sectors.attr,
-	&tcmu_dev_attrib_hw_queue_depth.attr,
-	NULL,
-};
-
-static struct se_subsystem_api tcmu_template = {
+static const struct target_backend_ops tcmu_ops = {
 	.name			= "user",
 	.inquiry_prod		= "USER",
 	.inquiry_rev		= TCMU_VERSION,
@@ -1090,11 +1121,11 @@ static struct se_subsystem_api tcmu_template = {
 	.show_configfs_dev_params = tcmu_show_configfs_dev_params,
 	.get_device_type	= sbc_get_device_type,
 	.get_blocks		= tcmu_get_blocks,
+	.tb_dev_attrib_attrs	= passthrough_attrib_attrs,
 };
 
 static int __init tcmu_module_init(void)
 {
-	struct target_backend_cits *tbc = &tcmu_template.tb_cits;
 	int ret;
 
 	BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
@@ -1117,10 +1148,7 @@ static int __init tcmu_module_init(void)
 		goto out_unreg_device;
 	}
 
-	target_core_setup_sub_cits(&tcmu_template);
-	tbc->tb_dev_attrib_cit.ct_attrs = tcmu_backend_dev_attrs;
-
-	ret = transport_subsystem_register(&tcmu_template);
+	ret = transport_backend_register(&tcmu_ops);
 	if (ret)
 		goto out_unreg_genl;
 
@@ -1138,7 +1166,7 @@ out_free_cache:
 
 static void __exit tcmu_module_exit(void)
 {
-	transport_subsystem_release(&tcmu_template);
+	target_backend_unregister(&tcmu_ops);
 	genl_unregister_family(&tcmu_genl_family);
 	root_device_unregister(tcmu_root_device);
 	kmem_cache_destroy(tcmu_cmd_cache);