block: provide a request helper for user integrity segments

Provide a helper to keep the request flags and nr_integrity_segments in
sync with the bio's integrity payload. This is an integrity equivalent
to the normal data helper function, 'blk_rq_map_user()'.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20240913182854.2445457-6-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: keithbusch

block/bio-integrity.c

@@ -371,7 +371,6 @@ int bio_integrity_map_user(struct bio *bio, void __user *ubuf, ssize_t bytes,
 		kfree(bvec);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(bio_integrity_map_user);
 
 /**
  * bio_integrity_prep - Prepare bio for integrity I/O

block/blk-integrity.c

@@ -107,6 +107,20 @@ int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
 }
 EXPORT_SYMBOL(blk_rq_map_integrity_sg);
 
+int blk_rq_integrity_map_user(struct request *rq, void __user *ubuf,
+			      ssize_t bytes, u32 seed)
+{
+	int ret = bio_integrity_map_user(rq->bio, ubuf, bytes, seed);
+
+	if (ret)
+		return ret;
+
+	rq->nr_integrity_segments = blk_rq_count_integrity_sg(rq->q, rq->bio);
+	rq->cmd_flags |= REQ_INTEGRITY;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(blk_rq_integrity_map_user);
+
 bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
 			    struct request *next)
 {

drivers/nvme/host/ioctl.c

@@ -3,7 +3,6 @@
  * Copyright (c) 2011-2014, Intel Corporation.
  * Copyright (c) 2017-2021 Christoph Hellwig.
  */
-#include <linux/bio-integrity.h>
 #include <linux/blk-integrity.h>
 #include <linux/ptrace.h>	/* for force_successful_syscall_return */
 #include <linux/nvme_ioctl.h>
@@ -153,11 +152,10 @@ static int nvme_map_user_request(struct request *req, u64 ubuffer,
 		bio_set_dev(bio, bdev);
 
 	if (has_metadata) {
-		ret = bio_integrity_map_user(bio, meta_buffer, meta_len,
-					     meta_seed);
+		ret = blk_rq_integrity_map_user(req, meta_buffer, meta_len,
+						meta_seed);
 		if (ret)
 			goto out_unmap;
-		req->cmd_flags |= REQ_INTEGRITY;
 	}
 
 	return ret;

include/linux/blk-integrity.h

@@ -28,6 +28,8 @@ static inline bool queue_limits_stack_integrity_bdev(struct queue_limits *t,
 int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
 				   struct scatterlist *);
 int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
+int blk_rq_integrity_map_user(struct request *rq, void __user *ubuf,
+			      ssize_t bytes, u32 seed);
 
 static inline bool
 blk_integrity_queue_supports_integrity(struct request_queue *q)
@@ -102,6 +104,13 @@ static inline int blk_rq_map_integrity_sg(struct request_queue *q,
 {
 	return 0;
 }
+static inline int blk_rq_integrity_map_user(struct request *rq,
+					    void __user *ubuf,
+					    ssize_t bytes,
+					    u32 seed)
+{
+	return -EINVAL;
+}
 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
 {
 	return NULL;