OpenCAS Linux kernel 5.15 adaptation

This patch adapts OpenCAS Linux to compile and work with kernel v5.15

Commit id's from the kernel affecting OpenCAS:

commit 0e0ccdecb3cff95a350b4364e7ebbaa754d0e47d
    block: remove bdget_disk

commit 9c2b9dbafc067e173db30c4fd0636392d27944e8
    block: remove alloc_disk and alloc_disk_node

commit a8698707a1835be3abd12a3b28079a80999f8dee
    block: move bd_mutex to struct gendisk

commit 2cece3778475abc855084d897a3cf61249798ad9
    scsi: scsi_ioctl: Remove scsi_req_init()

commit 2f4731dcd0bb73379fbb9e3eb07ae7324125caef
    block: remove bdput

commit 14cf1dbb55bb07427babee425fd2a8a9300737cc
    block: remove bdgrab

Signed-off-by: Krzysztof Majzerowicz-Jaszcz <krzysztof.majzerowicz-jaszcz@intel.com>

configure.d/1_alloc_disk.conf

@@ -0,0 +1,75 @@
+#!/bin/bash
+#
+# Copyright(c) 2012-2022 Intel Corporation
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+. $(dirname $3)/conf_framework
+
+
+check() {
+	cur_name=$(basename $2)
+	config_file_path=$1
+	if compile_module $cur_name "blk_mq_alloc_disk(NULL, NULL);" "linux/blk-mq.h"
+	then
+		echo $cur_name 1 >> $config_file_path
+	else
+		echo $cur_name 2 >> $config_file_path
+	fi
+}
+
+apply() {
+    case "$1" in
+    "1")
+        add_function "
+        static inline int cas_alloc_mq_disk(struct gendisk **gd, struct request_queue **queue,
+					    struct blk_mq_tag_set *tag_set)
+        {
+		*gd = blk_mq_alloc_disk(tag_set, NULL);
+		if (!(*gd))
+			return -ENOMEM;
+
+		*queue = (*gd)->queue;
+
+		return 0;
+        }"
+	add_function "
+	static inline void cas_cleanup_mq_disk(struct casdsk_exp_obj *exp_obj)
+	{
+		blk_cleanup_disk(exp_obj->gd);
+	}"
+	;;
+
+    "2")
+
+	add_function "
+        static inline int cas_alloc_mq_disk(struct gendisk **gd, struct request_queue **queue,
+					    struct blk_mq_tag_set *tag_set)
+        {
+		*gd = alloc_disk(1);
+		if (!(*gd))
+			return -ENOMEM;
+
+		*queue = blk_mq_init_queue(tag_set);
+		if (IS_ERR_OR_NULL(*queue)) {
+			put_disk(*gd);
+			return -ENOMEM;
+		}
+		(*gd)->queue = *queue;
+
+		return 0;
+        }"
+
+	add_function "
+	static inline void cas_cleanup_mq_disk(struct casdsk_exp_obj *exp_obj){
+		blk_cleanup_queue(exp_obj->queue);
+		put_disk(exp_obj->gd);
+	}"
+	;;
+
+    *)
+        exit 1
+    esac
+}
+
+conf_run $@

configure.d/1_bdget_disk.conf

@@ -1,43 +0,0 @@
-#!/bin/bash
-#
-# Copyright(c) 2012-2021 Intel Corporation
-# SPDX-License-Identifier: BSD-3-Clause
-#
-
-. $(dirname $3)/conf_framework
-
-
-check() {
-	cur_name=$(basename $2)
-	config_file_path=$1
-    if compile_module $cur_name "bdget_disk(NULL, 0);" "linux/genhd.h"
-    then
-        echo $cur_name 1 >> $config_file_path
-    elif compile_module $cur_name "bdgrab(NULL);" "linux/blkdev.h"
-    then
-        echo $cur_name 2 >> $config_file_path
-    else
-        echo $cur_name X >> $config_file_path
-    fi
-}
-
-apply() {
-    case "$1" in
-    "1")
-        add_function "
-        static inline struct block_device *cas_bdget_disk(struct gendisk *gd)
-        {
-            return bdget_disk(gd, 0);
-        }" ;;
-    "2")
-        add_function "
-        static inline struct block_device *cas_bdget_disk(struct gendisk *gd)
-        {
-            return bdgrab(gd->part0);
-        }" ;;
-    *)
-        exit 1
-    esac
-}
-
-conf_run $@

configure.d/1_block_pc.conf

@@ -34,7 +34,12 @@ apply() {
         {
             struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
 
-            scsi_req_init(&cmd->req);
+	    struct scsi_request *req = &cmd->req;
+
+	    memset(req->__cmd, 0, sizeof(req->__cmd));
+	    req->cmd = req->__cmd;
+            req->cmd_len = BLK_MAX_CDB;
+            req->sense_len = 0;
         }" ;;
     *)
         exit 1

configure.d/1_reread_partitions.conf

@@ -23,7 +23,7 @@ apply() {
         add_function "
         static inline void cas_reread_partitions(struct block_device *bdev)
         {
-            bdev_disk_changed(bdev, false);
+            bdev_disk_changed(bdev->bd_disk, false);
         }" ;;
     "2")
         add_function "

modules/cas_cache/linux_kernel_version.h

@@ -1,5 +1,5 @@
 /*
-* Copyright(c) 2012-2021 Intel Corporation
+* Copyright(c) 2012-2022 Intel Corporation
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
@@ -40,6 +40,7 @@
 #include <linux/mm.h>
 #include <linux/blk-mq.h>
 #include <linux/ktime.h>
+#include "../cas_disk/exp_obj.h"
 
 #include "generated_defines.h"
 

modules/cas_cache/volume/vol_block_dev_top.c

@@ -1,5 +1,5 @@
 /*
-* Copyright(c) 2012-2021 Intel Corporation
+* Copyright(c) 2012-2022 Intel Corporation
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
@@ -713,13 +713,14 @@ static int kcas_core_lock_exported_object(ocf_core_t core, void *cntx)
 	}
 
 	bvol->expobj_locked = true;
+
 	return 0;
 }
 
+
 static int kcas_core_unlock_exported_object(ocf_core_t core, void *cntx)
 {
-	struct bd_object *bvol = bd_object(
-			ocf_core_get_volume(core));
+	struct bd_object *bvol = bd_object(ocf_core_get_volume(core));
 
 	if (bvol->expobj_locked) {
 		casdisk_functions.casdsk_exp_obj_unlock(bvol->dsk);

modules/cas_disk/disk.c

@@ -1,5 +1,5 @@
 /*
-* Copyright(c) 2012-2021 Intel Corporation
+* Copyright(c) 2012-2022 Intel Corporation
 * SPDX-License-Identifier: BSD-3-Clause
 */
 #include <linux/module.h>
@@ -126,6 +126,8 @@ struct casdsk_disk *casdsk_disk_open(const char *path, void *private)
 	}
 	mutex_init(&dsk->lock);
 
+	mutex_init(&dsk->openers_lock);
+
 	dsk->path = kstrdup(path, GFP_KERNEL);
 	if (!dsk->path) {
 		result = -ENOMEM;

modules/cas_disk/disk.h

@@ -1,5 +1,5 @@
 /*
-* Copyright(c) 2012-2021 Intel Corporation
+* Copyright(c) 2012-2022 Intel Corporation
 * SPDX-License-Identifier: BSD-3-Clause
 */
 #ifndef __
@@ -31,6 +31,10 @@ struct casdsk_disk {
 
 	struct mutex lock;
 
+	struct mutex openers_lock;
+	unsigned int openers;
+	bool claimed;
+
 	struct block_device *bd;
 
 	int gd_flags;

modules/cas_disk/exp_obj.c

@@ -1,5 +1,5 @@
 /*
-* Copyright(c) 2012-2021 Intel Corporation
+* Copyright(c) 2012-2022 Intel Corporation
 * SPDX-License-Identifier: BSD-3-Clause
 */
 #include <linux/module.h>
@@ -339,8 +339,38 @@ static void _casdsk_exp_obj_clear_dev_t(struct casdsk_disk *dsk)
 	}
 }
 
+static int _casdsk_exp_obj_open(struct block_device *bdev, fmode_t mode)
+{
+	struct casdsk_disk *dsk = bdev->bd_disk->private_data;
+	int result = -ENAVAIL;
+
+	mutex_lock(&dsk->openers_lock);
+
+	if (!dsk->claimed) {
+		dsk->openers++;
+		result = 0;
+	}
+
+	mutex_unlock(&dsk->openers_lock);
+	return result;
+}
+
+static void _casdsk_exp_obj_close(struct gendisk *gd, fmode_t mode)
+{
+	struct casdsk_disk *dsk = gd->private_data;
+
+	BUG_ON(dsk->openers == 0);
+
+	mutex_lock(&dsk->openers_lock);
+	dsk->openers--;
+	mutex_unlock(&dsk->openers_lock);
+
+}
+
 static const struct block_device_operations _casdsk_exp_obj_ops = {
 	.owner = THIS_MODULE,
+	.open = _casdsk_exp_obj_open,
+	.release = _casdsk_exp_obj_close,
 	CAS_SET_SUBMIT_BIO(_casdsk_exp_obj_submit_bio)
 };
 
@@ -371,7 +401,6 @@ static int casdsk_exp_obj_alloc(struct casdsk_disk *dsk)
 	dsk->exp_obj = exp_obj;
 
 	return 0;
-
 error_pending_rqs_alloc:
 	kmem_cache_free(casdsk_module->exp_obj_cache, exp_obj);
 error_exp_obj_alloc:
@@ -396,7 +425,6 @@ EXPORT_SYMBOL(casdsk_exp_obj_free);
 
 static void __casdsk_exp_obj_release(struct casdsk_exp_obj *exp_obj)
 {
-	kfree(exp_obj->dev_name);
 	kmem_cache_free(casdsk_module->pending_rqs_cache, exp_obj->pending_rqs);
 	kmem_cache_free(casdsk_module->exp_obj_cache, exp_obj);
 }
@@ -415,6 +443,7 @@ static void _casdsk_exp_obj_release(struct kobject *kobj)
 
 	owner = exp_obj->owner;
 
+	kfree(exp_obj->dev_name);
 	__casdsk_exp_obj_release(exp_obj);
 
 	if (owner)
@@ -505,53 +534,45 @@ int casdsk_exp_obj_create(struct casdsk_disk *dsk, const char *dev_name,
 
 	result = casdsk_exp_obj_alloc(dsk);
 	if (result)
-		goto error_alloc;
+		goto error_exp_obj_alloc;
 
 	exp_obj = dsk->exp_obj;
 
 	exp_obj->dev_name = kstrdup(dev_name, GFP_KERNEL);
 	if (!exp_obj->dev_name) {
-		__casdsk_exp_obj_release(exp_obj);
 		result = -ENOMEM;
-		goto error_strdup;
-	}
-
-	result = _casdsk_exp_obj_init_kobject(dsk);
-	if (result) {
-		__casdsk_exp_obj_release(exp_obj);
-		goto error_kobject;
+		goto error_kstrdup;
 	}
 
 	if (!try_module_get(owner)) {
 		CASDSK_DEBUG_DISK_ERROR(dsk, "Cannot get reference to module");
 		result = -ENAVAIL;
-		goto error_module;
+		goto error_module_get;
 	}
 	exp_obj->owner = owner;
 	exp_obj->ops = ops;
 
-	gd = alloc_disk(1);
-	if (!gd) {
-		result = -ENOMEM;
-		goto error_alloc_disk;
+	result = _casdsk_exp_obj_init_kobject(dsk);
+	if (result) {
+		goto error_init_kobject;
 	}
-	exp_obj->gd = gd;
-
-	result = _casdsk_exp_obj_set_dev_t(dsk, gd);
-	if (result)
-		goto error_dev_t;
 
 	result = _casdsk_init_tag_set(dsk, &dsk->tag_set);
 	if (result) {
 		goto error_init_tag_set;
 	}
 
-	queue = blk_mq_init_queue(&dsk->tag_set);
-	if (IS_ERR_OR_NULL(queue)) {
-		result = queue ? PTR_ERR(queue) : -ENOMEM;
-		goto error_init_queue;
+	result = cas_alloc_mq_disk(&gd, &queue, &dsk->tag_set);
+	if (result) {
+		goto error_alloc_mq_disk;
 	}
 
+	exp_obj->gd = gd;
+
+	result = _casdsk_exp_obj_set_dev_t(dsk, gd);
+	if (result)
+		goto error_exp_obj_set_dev_t;
+
 	BUG_ON(queue->queuedata);
 	queue->queuedata = dsk;
 	exp_obj->queue = queue;
@@ -559,7 +580,6 @@ int casdsk_exp_obj_create(struct casdsk_disk *dsk, const char *dev_name,
 	_casdsk_init_queues(dsk);
 
 	gd->fops = &_casdsk_exp_obj_ops;
-	gd->queue = queue;
 	gd->private_data = dsk;
 	strlcpy(gd->disk_name, exp_obj->dev_name, sizeof(gd->disk_name));
 
@@ -574,23 +594,27 @@ int casdsk_exp_obj_create(struct casdsk_disk *dsk, const char *dev_name,
 	return 0;
 
 error_set_geometry:
-	blk_cleanup_queue(exp_obj->queue);
-error_init_queue:
+	_casdsk_exp_obj_clear_dev_t(dsk);
+error_exp_obj_set_dev_t:
+	cas_cleanup_mq_disk(exp_obj);
+	dsk->exp_obj->gd = NULL;
+error_alloc_mq_disk:
 	blk_mq_free_tag_set(&dsk->tag_set);
 error_init_tag_set:
-	_casdsk_exp_obj_clear_dev_t(dsk);
-error_dev_t:
-	put_disk(gd);
-error_alloc_disk:
+	kobject_put(&exp_obj->kobj);
+	/* kobject put does all the cleanup below internally */
+	return result;
+error_init_kobject:
 	module_put(owner);
 	dsk->exp_obj->owner = NULL;
-error_module:
-	casdsk_exp_obj_free(dsk);
-error_kobject:
-error_strdup:
+error_module_get:
+	kfree(exp_obj->dev_name);
+error_kstrdup:
+	__casdsk_exp_obj_release(exp_obj);
 	dsk->exp_obj = NULL;
-error_alloc:
+error_exp_obj_alloc:
 	return result;
+
 }
 EXPORT_SYMBOL(casdsk_exp_obj_create);
 
@@ -689,6 +713,7 @@ EXPORT_SYMBOL(casdsk_exp_obj_activated);
 int casdsk_exp_obj_lock(struct casdsk_disk *dsk)
 {
 	struct casdsk_exp_obj *exp_obj;
+	int result = -EBUSY;
 
 	BUG_ON(!dsk);
 	BUG_ON(!dsk->exp_obj);
@@ -697,36 +722,26 @@ int casdsk_exp_obj_lock(struct casdsk_disk *dsk)
 
 	exp_obj = dsk->exp_obj;
 
-	exp_obj->locked_bd = cas_bdget_disk(exp_obj->gd);
-	if (!exp_obj->locked_bd)
-		return -ENAVAIL;
+	mutex_lock(&dsk->openers_lock);
 
-	mutex_lock(&exp_obj->locked_bd->bd_mutex);
-
-	if (exp_obj->locked_bd->bd_openers) {
-		printk(CASDSK_KERN_DEBUG "Device %s in use (openers=%d). Refuse to stop\n",
-		       exp_obj->locked_bd->bd_disk->disk_name,
-		       exp_obj->locked_bd->bd_openers);
-
-		casdsk_exp_obj_unlock(dsk);
-		return -EBUSY;
+	if (dsk->openers == 0) {
+		dsk->claimed = true;
+		result = 0;
 	}
 
-	return 0;
+	mutex_unlock(&dsk->openers_lock);
+	return result;
 }
 EXPORT_SYMBOL(casdsk_exp_obj_lock);
 
 int casdsk_exp_obj_unlock(struct casdsk_disk *dsk)
 {
 	BUG_ON(!dsk);
-	BUG_ON(!dsk->exp_obj);
-	BUG_ON(!dsk->exp_obj->locked_bd);
-
 	CASDSK_DEBUG_DISK_TRACE(dsk);
 
-	mutex_unlock(&dsk->exp_obj->locked_bd->bd_mutex);
-	bdput(dsk->exp_obj->locked_bd);
-	dsk->exp_obj->locked_bd = NULL;
+	mutex_lock(&dsk->openers_lock);
+	dsk->claimed = false;
+	mutex_unlock(&dsk->openers_lock);
 
 	return 0;
 }
@@ -741,8 +756,6 @@ int casdsk_exp_obj_destroy(struct casdsk_disk *dsk)
 	if (!dsk->exp_obj)
 		return -ENODEV;
 
-	BUG_ON(!dsk->exp_obj->locked_bd);
-
 	CASDSK_DEBUG_DISK_TRACE(dsk);
 
 	exp_obj = dsk->exp_obj;

modules/cas_disk/exp_obj.h

@@ -1,5 +1,5 @@
 /*
-* Copyright(c) 2012-2021 Intel Corporation
+* Copyright(c) 2012-2022 Intel Corporation
 * SPDX-License-Identifier: BSD-3-Clause
 */
 #ifndef __CASDISK_EXP_OBJ_H__