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From: Anuj Gupta <[email protected]>
To: [email protected], [email protected], [email protected]
Cc: [email protected], [email protected],
	[email protected], [email protected],
	[email protected], Kanchan Joshi <[email protected]>,
	Anuj Gupta <[email protected]>
Subject: [PATCH for-next v11 07/13] block: add blk_rq_map_user_bvec
Date: Thu, 29 Sep 2022 17:36:26 +0530	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

From: Kanchan Joshi <[email protected]>

This is a prep patch. This function maps the pages from bvec iterator into
a bio and place the bio into request.

This helper will be used by nvme for uring-passthrough path when IO is
done using pre-mapped buffers.

Signed-off-by: Kanchan Joshi <[email protected]>
Signed-off-by: Anuj Gupta <[email protected]>
Suggested-by: Christoph Hellwig <[email protected]>
---
 block/blk-map.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/block/blk-map.c b/block/blk-map.c
index 9e37a03b8a21..023b63ad06d8 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -548,6 +548,62 @@ int blk_rq_append_bio(struct request *rq, struct bio *bio)
 }
 EXPORT_SYMBOL(blk_rq_append_bio);
 
+/* Prepare bio for passthrough IO given ITER_BVEC iter */
+static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter)
+{
+	struct request_queue *q = rq->q;
+	size_t nr_iter = iov_iter_count(iter);
+	size_t nr_segs = iter->nr_segs;
+	struct bio_vec *bvecs, *bvprvp = NULL;
+	struct queue_limits *lim = &q->limits;
+	unsigned int nsegs = 0, bytes = 0;
+	struct bio *bio;
+	size_t i;
+
+	if (!nr_iter || (nr_iter >> SECTOR_SHIFT) > queue_max_hw_sectors(q))
+		return -EINVAL;
+	if (nr_segs > queue_max_segments(q))
+		return -EINVAL;
+
+	/* no iovecs to alloc, as we already have a BVEC iterator */
+	bio = blk_rq_map_bio_alloc(rq, 0, GFP_KERNEL);
+	if (bio == NULL)
+		return -ENOMEM;
+
+	bio_iov_bvec_set(bio, (struct iov_iter *)iter);
+	blk_rq_bio_prep(rq, bio, nr_segs);
+
+	/* loop to perform a bunch of sanity checks */
+	bvecs = (struct bio_vec *)iter->bvec;
+	for (i = 0; i < nr_segs; i++) {
+		struct bio_vec *bv = &bvecs[i];
+
+		/*
+		 * If the queue doesn't support SG gaps and adding this
+		 * offset would create a gap, fallback to copy.
+		 */
+		if (bvprvp && bvec_gap_to_prev(lim, bvprvp, bv->bv_offset)) {
+			blk_mq_map_bio_put(bio);
+			return -EREMOTEIO;
+		}
+		/* check full condition */
+		if (nsegs >= nr_segs || bytes > UINT_MAX - bv->bv_len)
+			goto put_bio;
+		if (bytes + bv->bv_len > nr_iter)
+			goto put_bio;
+		if (bv->bv_offset + bv->bv_len > PAGE_SIZE)
+			goto put_bio;
+
+		nsegs++;
+		bytes += bv->bv_len;
+		bvprvp = bv;
+	}
+	return 0;
+put_bio:
+	blk_mq_map_bio_put(bio);
+	return -EINVAL;
+}
+
 /**
  * blk_rq_map_user_iov - map user data to a request, for passthrough requests
  * @q:		request queue where request should be inserted
-- 
2.25.1


  parent reply	other threads:[~2022-09-29 12:23 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20220929121630epcas5p3e1ed2c5251276d557f8f921e8186620f@epcas5p3.samsung.com>
2022-09-29 12:06 ` [PATCH for-next v11 00/13] Fixed-buffer for uring-cmd/passthru Anuj Gupta
     [not found]   ` <CGME20220929121634epcas5p27400b84f8a8b43a91c4199ec39d50b51@epcas5p2.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 01/13] io_uring: add io_uring_cmd_import_fixed Anuj Gupta
     [not found]   ` <CGME20220929121637epcas5p2ff344c7951037f79d117d000e405dd45@epcas5p2.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 02/13] io_uring: introduce fixed buffer support for io_uring_cmd Anuj Gupta
2022-09-30  1:26       ` Jens Axboe
     [not found]   ` <CGME20220929121640epcas5p400a71aa51f374f016e2143d0228879bc@epcas5p4.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 03/13] nvme: refactor nvme_add_user_metadata Anuj Gupta
     [not found]   ` <CGME20220929121643epcas5p4c58f6ebb794bde58981272cd33c69f9f@epcas5p4.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 04/13] nvme: refactor nvme_alloc_request Anuj Gupta
2022-09-29 13:25       ` Christoph Hellwig
     [not found]   ` <CGME20220929121647epcas5p2d4ca8ae0b83a1fce230914f586ee3cc0@epcas5p2.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 05/13] block: rename bio_map_put to blk_mq_map_bio_put Anuj Gupta
2022-09-29 13:25       ` Christoph Hellwig
     [not found]   ` <CGME20220929121650epcas5p424925af86ec6941bb53e5c102fd0ffc8@epcas5p4.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 06/13] block: factor out blk_rq_map_bio_alloc helper Anuj Gupta
     [not found]   ` <CGME20220929121653epcas5p4ee82ef35b46d6686820dc4d870b6588e@epcas5p4.samsung.com>
2022-09-29 12:06     ` Anuj Gupta [this message]
2022-09-29 13:26       ` [PATCH for-next v11 07/13] block: add blk_rq_map_user_bvec Christoph Hellwig
     [not found]   ` <CGME20220929121657epcas5p213b7a187fd77b0783adb4b9389579b44@epcas5p2.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 08/13] block: extend functionality to map bvec iterator Anuj Gupta
     [not found]   ` <CGME20220929121701epcas5p287a6d3f851626a5c7580d9a534432e9b@epcas5p2.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 09/13] nvme: pass ubuffer as an integer Anuj Gupta
2022-09-29 13:27       ` Christoph Hellwig
     [not found]   ` <CGME20220929121704epcas5p3415fd4782cbcffa7b1e6ddf774bebb03@epcas5p3.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 10/13] nvme: wire up fixed buffer support for nvme passthrough Anuj Gupta
     [not found]   ` <CGME20220929121709epcas5p325553d10a7ada7717c2f51ddb566a3e5@epcas5p3.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 11/13] block: add blk_rq_map_user_io Anuj Gupta
2022-09-29 13:28       ` Christoph Hellwig
     [not found]   ` <CGME20220929121713epcas5p1824ed0c48c9e9ceeb18954d9c23564ed@epcas5p1.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 12/13] scsi: Use blk_rq_map_user_io helper Anuj Gupta
2022-09-29 13:28       ` Christoph Hellwig
     [not found]   ` <CGME20220929121715epcas5p488759f34f6e55d940c6dca523e24f464@epcas5p4.samsung.com>
2022-09-29 12:06     ` [PATCH for-next v11 13/13] nvme: " Anuj Gupta

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