1 files changed, 40 insertions, 125 deletions

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 7921573aebbc..3afe327f816f 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -1,17 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2017 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
 #include <linux/kernel.h>
@@ -115,7 +104,6 @@ static int queue_pm_only_show(void *data, struct seq_file *m)
 static const char *const blk_queue_flag_name[] = {
 	QUEUE_FLAG_NAME(STOPPED),
 	QUEUE_FLAG_NAME(DYING),
-	QUEUE_FLAG_NAME(BIDI),
 	QUEUE_FLAG_NAME(NOMERGES),
 	QUEUE_FLAG_NAME(SAME_COMP),
 	QUEUE_FLAG_NAME(FAIL_IO),
@@ -128,11 +116,9 @@ static const char *const blk_queue_flag_name[] = {
 	QUEUE_FLAG_NAME(SAME_FORCE),
 	QUEUE_FLAG_NAME(DEAD),
 	QUEUE_FLAG_NAME(INIT_DONE),
-	QUEUE_FLAG_NAME(NO_SG_MERGE),
 	QUEUE_FLAG_NAME(POLL),
 	QUEUE_FLAG_NAME(WC),
 	QUEUE_FLAG_NAME(FUA),
-	QUEUE_FLAG_NAME(FLUSH_NQ),
 	QUEUE_FLAG_NAME(DAX),
 	QUEUE_FLAG_NAME(STATS),
 	QUEUE_FLAG_NAME(POLL_STATS),
@@ -251,7 +237,6 @@ static const char *const alloc_policy_name[] = {
 static const char *const hctx_flag_name[] = {
 	HCTX_FLAG_NAME(SHOULD_MERGE),
 	HCTX_FLAG_NAME(TAG_SHARED),
-	HCTX_FLAG_NAME(SG_MERGE),
 	HCTX_FLAG_NAME(BLOCKING),
 	HCTX_FLAG_NAME(NO_SCHED),
 };
@@ -836,38 +821,28 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 	{},
 };
 
-static bool debugfs_create_files(struct dentry *parent, void *data,
+static void debugfs_create_files(struct dentry *parent, void *data,
 				 const struct blk_mq_debugfs_attr *attr)
 {
 	if (IS_ERR_OR_NULL(parent))
-		return false;
+		return;
 
 	d_inode(parent)->i_private = data;
 
-	for (; attr->name; attr++) {
-		if (!debugfs_create_file(attr->name, attr->mode, parent,
-					 (void *)attr, &blk_mq_debugfs_fops))
-			return false;
-	}
-	return true;
+	for (; attr->name; attr++)
+		debugfs_create_file(attr->name, attr->mode, parent,
+				    (void *)attr, &blk_mq_debugfs_fops);
 }
 
-int blk_mq_debugfs_register(struct request_queue *q)
+void blk_mq_debugfs_register(struct request_queue *q)
 {
 	struct blk_mq_hw_ctx *hctx;
 	int i;
 
-	if (!blk_debugfs_root)
-		return -ENOENT;
-
 	q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 					    blk_debugfs_root);
-	if (!q->debugfs_dir)
-		return -ENOMEM;
 
-	if (!debugfs_create_files(q->debugfs_dir, q,
-				  blk_mq_debugfs_queue_attrs))
-		goto err;
+	debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
 
 	/*
 	 * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
@@ -879,11 +854,10 @@ int blk_mq_debugfs_register(struct request_queue *q)
 
 	/* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 	queue_for_each_hw_ctx(q, hctx, i) {
-		if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
-			goto err;
-		if (q->elevator && !hctx->sched_debugfs_dir &&
-		    blk_mq_debugfs_register_sched_hctx(q, hctx))
-			goto err;
+		if (!hctx->debugfs_dir)
+			blk_mq_debugfs_register_hctx(q, hctx);
+		if (q->elevator && !hctx->sched_debugfs_dir)
+			blk_mq_debugfs_register_sched_hctx(q, hctx);
 	}
 
 	if (q->rq_qos) {
@@ -894,12 +868,6 @@ int blk_mq_debugfs_register(struct request_queue *q)
 			rqos = rqos->next;
 		}
 	}
-
-	return 0;
-
-err:
-	blk_mq_debugfs_unregister(q);
-	return -ENOMEM;
 }
 
 void blk_mq_debugfs_unregister(struct request_queue *q)
@@ -909,52 +877,32 @@ void blk_mq_debugfs_unregister(struct request_queue *q)
 	q->debugfs_dir = NULL;
 }
 
-static int blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
-				       struct blk_mq_ctx *ctx)
+static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
+					struct blk_mq_ctx *ctx)
 {
 	struct dentry *ctx_dir;
 	char name[20];
 
 	snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 	ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
-	if (!ctx_dir)
-		return -ENOMEM;
 
-	if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
-		return -ENOMEM;
-
-	return 0;
+	debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
 }
 
-int blk_mq_debugfs_register_hctx(struct request_queue *q,
-				 struct blk_mq_hw_ctx *hctx)
+void blk_mq_debugfs_register_hctx(struct request_queue *q,
+				  struct blk_mq_hw_ctx *hctx)
 {
 	struct blk_mq_ctx *ctx;
 	char name[20];
 	int i;
 
-	if (!q->debugfs_dir)
-		return -ENOENT;
-
 	snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 	hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
-	if (!hctx->debugfs_dir)
-		return -ENOMEM;
 
-	if (!debugfs_create_files(hctx->debugfs_dir, hctx,
-				  blk_mq_debugfs_hctx_attrs))
-		goto err;
-
-	hctx_for_each_ctx(hctx, ctx, i) {
-		if (blk_mq_debugfs_register_ctx(hctx, ctx))
-			goto err;
-	}
+	debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
 
-	return 0;
-
-err:
-	blk_mq_debugfs_unregister_hctx(hctx);
-	return -ENOMEM;
+	hctx_for_each_ctx(hctx, ctx, i)
+		blk_mq_debugfs_register_ctx(hctx, ctx);
 }
 
 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
@@ -964,17 +912,13 @@ void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 	hctx->debugfs_dir = NULL;
 }
 
-int blk_mq_debugfs_register_hctxs(struct request_queue *q)
+void blk_mq_debugfs_register_hctxs(struct request_queue *q)
 {
 	struct blk_mq_hw_ctx *hctx;
 	int i;
 
-	queue_for_each_hw_ctx(q, hctx, i) {
-		if (blk_mq_debugfs_register_hctx(q, hctx))
-			return -ENOMEM;
-	}
-
-	return 0;
+	queue_for_each_hw_ctx(q, hctx, i)
+		blk_mq_debugfs_register_hctx(q, hctx);
 }
 
 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
@@ -986,29 +930,23 @@ void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 		blk_mq_debugfs_unregister_hctx(hctx);
 }
 
-int blk_mq_debugfs_register_sched(struct request_queue *q)
+void blk_mq_debugfs_register_sched(struct request_queue *q)
 {
 	struct elevator_type *e = q->elevator->type;
 
+	/*
+	 * If the parent directory has not been created yet, return, we will be
+	 * called again later on and the directory/files will be created then.
+	 */
 	if (!q->debugfs_dir)
-		return -ENOENT;
+		return;
 
 	if (!e->queue_debugfs_attrs)
-		return 0;
+		return;
 
 	q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
-	if (!q->sched_debugfs_dir)
-		return -ENOMEM;
-
-	if (!debugfs_create_files(q->sched_debugfs_dir, q,
-				  e->queue_debugfs_attrs))
-		goto err;
 
-	return 0;
-
-err:
-	blk_mq_debugfs_unregister_sched(q);
-	return -ENOMEM;
+	debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
 }
 
 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
@@ -1023,36 +961,22 @@ void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 	rqos->debugfs_dir = NULL;
 }
 
-int blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
+void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 {
 	struct request_queue *q = rqos->q;
 	const char *dir_name = rq_qos_id_to_name(rqos->id);
 
-	if (!q->debugfs_dir)
-		return -ENOENT;
-
 	if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
-		return 0;
+		return;
 
-	if (!q->rqos_debugfs_dir) {
+	if (!q->rqos_debugfs_dir)
 		q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 							 q->debugfs_dir);
-		if (!q->rqos_debugfs_dir)
-			return -ENOMEM;
-	}
 
 	rqos->debugfs_dir = debugfs_create_dir(dir_name,
 					       rqos->q->rqos_debugfs_dir);
-	if (!rqos->debugfs_dir)
-		return -ENOMEM;
 
-	if (!debugfs_create_files(rqos->debugfs_dir, rqos,
-				  rqos->ops->debugfs_attrs))
-		goto err;
-	return 0;
- err:
-	blk_mq_debugfs_unregister_rqos(rqos);
-	return -ENOMEM;
+	debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 }
 
 void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
@@ -1061,27 +985,18 @@ void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
 	q->rqos_debugfs_dir = NULL;
 }
 
-int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
-				       struct blk_mq_hw_ctx *hctx)
+void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+					struct blk_mq_hw_ctx *hctx)
 {
 	struct elevator_type *e = q->elevator->type;
 
-	if (!hctx->debugfs_dir)
-		return -ENOENT;
-
 	if (!e->hctx_debugfs_attrs)
-		return 0;
+		return;
 
 	hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 						     hctx->debugfs_dir);
-	if (!hctx->sched_debugfs_dir)
-		return -ENOMEM;
-
-	if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,
-				  e->hctx_debugfs_attrs))
-		return -ENOMEM;
-
-	return 0;
+	debugfs_create_files(hctx->sched_debugfs_dir, hctx,
+			     e->hctx_debugfs_attrs);
 }
 
 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)