smb: client: make use of smbdirect_map_sges_from_iter()

This is basically a copy of smb_extract_iter_to_rdma() moved
to common code.

Before we had the inconsistency we called ib_dma_unmap_single(),
while we mapped using ib_dma_map_page() in smb_set_sge().

Now ib_dma_unmap_page() is used for consistency.

It doesn't really matter as ib_dma_unmap_single() and
ib_dma_unmap_page() both operate
on dma_addr_t and dma_unmap_single_attrs() is just an
alias for dma_unmap_page_attrs().

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 5 insertions, 236 deletions

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index 28fb77b2661b..0ccea382fdaa 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -36,17 +36,6 @@ static int smbd_post_send_empty(struct smbdirect_socket *sc);
 static void destroy_mr_list(struct smbdirect_socket *sc);
 static int allocate_mr_list(struct smbdirect_socket *sc);
 
-struct smb_extract_to_rdma {
-	struct ib_sge		*sge;
-	unsigned int		nr_sge;
-	unsigned int		max_sge;
-	struct ib_device	*device;
-	u32			local_dma_lkey;
-	enum dma_data_direction	direction;
-};
-static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len,
-					struct smb_extract_to_rdma *rdma);
-
 /* Port numbers for SMBD transport */
 #define SMB_PORT	445
 #define SMBD_PORT	5445
@@ -1268,9 +1257,9 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 
 	/* Fill in the data payload to find out how much data we can add */
 	if (iter) {
-		struct smb_extract_to_rdma extract = {
-			.nr_sge		= request->num_sge,
-			.max_sge	= SMBDIRECT_SEND_IO_MAX_SGE,
+		struct smbdirect_map_sges extract = {
+			.num_sge	= request->num_sge,
+			.max_sge	= ARRAY_SIZE(request->sge),
 			.sge		= request->sge,
 			.device		= sc->ib.dev,
 			.local_dma_lkey	= sc->ib.pd->local_dma_lkey,
@@ -1279,12 +1268,11 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 		size_t payload_len = umin(*_remaining_data_length,
 					  sp->max_send_size - sizeof(*packet));
 
-		rc = smb_extract_iter_to_rdma(iter, payload_len,
-					      &extract);
+		rc = smbdirect_map_sges_from_iter(iter, payload_len, &extract);
 		if (rc < 0)
 			goto err_dma;
 		data_length = rc;
-		request->num_sge = extract.nr_sge;
+		request->num_sge = extract.num_sge;
 		*_remaining_data_length -= data_length;
 	} else {
 		data_length = 0;
@@ -2653,222 +2641,3 @@ put_kref:
 	if (!kref_put(&mr->kref, smbd_mr_free_locked))
 		mutex_unlock(&mr->mutex);
 }
-
-static bool smb_set_sge(struct smb_extract_to_rdma *rdma,
-			struct page *lowest_page, size_t off, size_t len)
-{
-	struct ib_sge *sge = &rdma->sge[rdma->nr_sge];
-	u64 addr;
-
-	addr = ib_dma_map_page(rdma->device, lowest_page,
-			       off, len, rdma->direction);
-	if (ib_dma_mapping_error(rdma->device, addr))
-		return false;
-
-	sge->addr   = addr;
-	sge->length = len;
-	sge->lkey   = rdma->local_dma_lkey;
-	rdma->nr_sge++;
-	return true;
-}
-
-/*
- * Extract page fragments from a BVEC-class iterator and add them to an RDMA
- * element list.  The pages are not pinned.
- */
-static ssize_t smb_extract_bvec_to_rdma(struct iov_iter *iter,
-					struct smb_extract_to_rdma *rdma,
-					ssize_t maxsize)
-{
-	const struct bio_vec *bv = iter->bvec;
-	unsigned long start = iter->iov_offset;
-	unsigned int i;
-	ssize_t ret = 0;
-
-	for (i = 0; i < iter->nr_segs; i++) {
-		size_t off, len;
-
-		len = bv[i].bv_len;
-		if (start >= len) {
-			start -= len;
-			continue;
-		}
-
-		len = min_t(size_t, maxsize, len - start);
-		off = bv[i].bv_offset + start;
-
-		if (!smb_set_sge(rdma, bv[i].bv_page, off, len))
-			return -EIO;
-
-		ret += len;
-		maxsize -= len;
-		if (rdma->nr_sge >= rdma->max_sge || maxsize <= 0)
-			break;
-		start = 0;
-	}
-
-	if (ret > 0)
-		iov_iter_advance(iter, ret);
-	return ret;
-}
-
-/*
- * Extract fragments from a KVEC-class iterator and add them to an RDMA list.
- * This can deal with vmalloc'd buffers as well as kmalloc'd or static buffers.
- * The pages are not pinned.
- */
-static ssize_t smb_extract_kvec_to_rdma(struct iov_iter *iter,
-					struct smb_extract_to_rdma *rdma,
-					ssize_t maxsize)
-{
-	const struct kvec *kv = iter->kvec;
-	unsigned long start = iter->iov_offset;
-	unsigned int i;
-	ssize_t ret = 0;
-
-	for (i = 0; i < iter->nr_segs; i++) {
-		struct page *page;
-		unsigned long kaddr;
-		size_t off, len, seg;
-
-		len = kv[i].iov_len;
-		if (start >= len) {
-			start -= len;
-			continue;
-		}
-
-		kaddr = (unsigned long)kv[i].iov_base + start;
-		off = kaddr & ~PAGE_MASK;
-		len = min_t(size_t, maxsize, len - start);
-		kaddr &= PAGE_MASK;
-
-		maxsize -= len;
-		do {
-			seg = min_t(size_t, len, PAGE_SIZE - off);
-
-			if (is_vmalloc_or_module_addr((void *)kaddr))
-				page = vmalloc_to_page((void *)kaddr);
-			else
-				page = virt_to_page((void *)kaddr);
-
-			if (!smb_set_sge(rdma, page, off, seg))
-				return -EIO;
-
-			ret += seg;
-			len -= seg;
-			kaddr += PAGE_SIZE;
-			off = 0;
-		} while (len > 0 && rdma->nr_sge < rdma->max_sge);
-
-		if (rdma->nr_sge >= rdma->max_sge || maxsize <= 0)
-			break;
-		start = 0;
-	}
-
-	if (ret > 0)
-		iov_iter_advance(iter, ret);
-	return ret;
-}
-
-/*
- * Extract folio fragments from a FOLIOQ-class iterator and add them to an RDMA
- * list.  The folios are not pinned.
- */
-static ssize_t smb_extract_folioq_to_rdma(struct iov_iter *iter,
-					  struct smb_extract_to_rdma *rdma,
-					  ssize_t maxsize)
-{
-	const struct folio_queue *folioq = iter->folioq;
-	unsigned int slot = iter->folioq_slot;
-	ssize_t ret = 0;
-	size_t offset = iter->iov_offset;
-
-	BUG_ON(!folioq);
-
-	if (slot >= folioq_nr_slots(folioq)) {
-		folioq = folioq->next;
-		if (WARN_ON_ONCE(!folioq))
-			return -EIO;
-		slot = 0;
-	}
-
-	do {
-		struct folio *folio = folioq_folio(folioq, slot);
-		size_t fsize = folioq_folio_size(folioq, slot);
-
-		if (offset < fsize) {
-			size_t part = umin(maxsize, fsize - offset);
-
-			if (!smb_set_sge(rdma, folio_page(folio, 0), offset, part))
-				return -EIO;
-
-			offset += part;
-			ret += part;
-			maxsize -= part;
-		}
-
-		if (offset >= fsize) {
-			offset = 0;
-			slot++;
-			if (slot >= folioq_nr_slots(folioq)) {
-				if (!folioq->next) {
-					WARN_ON_ONCE(ret < iter->count);
-					break;
-				}
-				folioq = folioq->next;
-				slot = 0;
-			}
-		}
-	} while (rdma->nr_sge < rdma->max_sge && maxsize > 0);
-
-	iter->folioq = folioq;
-	iter->folioq_slot = slot;
-	iter->iov_offset = offset;
-	iter->count -= ret;
-	return ret;
-}
-
-/*
- * Extract page fragments from up to the given amount of the source iterator
- * and build up an RDMA list that refers to all of those bits.  The RDMA list
- * is appended to, up to the maximum number of elements set in the parameter
- * block.
- *
- * The extracted page fragments are not pinned or ref'd in any way; if an
- * IOVEC/UBUF-type iterator is to be used, it should be converted to a
- * BVEC-type iterator and the pages pinned, ref'd or otherwise held in some
- * way.
- */
-static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len,
-					struct smb_extract_to_rdma *rdma)
-{
-	ssize_t ret;
-	int before = rdma->nr_sge;
-
-	switch (iov_iter_type(iter)) {
-	case ITER_BVEC:
-		ret = smb_extract_bvec_to_rdma(iter, rdma, len);
-		break;
-	case ITER_KVEC:
-		ret = smb_extract_kvec_to_rdma(iter, rdma, len);
-		break;
-	case ITER_FOLIOQ:
-		ret = smb_extract_folioq_to_rdma(iter, rdma, len);
-		break;
-	default:
-		WARN_ON_ONCE(1);
-		return -EIO;
-	}
-
-	if (ret < 0) {
-		while (rdma->nr_sge > before) {
-			struct ib_sge *sge = &rdma->sge[rdma->nr_sge--];
-
-			ib_dma_unmap_single(rdma->device, sge->addr, sge->length,
-					    rdma->direction);
-			sge->addr = 0;
-		}
-	}
-
-	return ret;
-}