[RFC PATCH 11/17] cifs: Remove support for ITER_KVEC/BVEC/FOLIOQ from smb_extract_iter_to_rdma()

[David Howells]

netfslib now only presents an bvecq queue and an associated ITER_BVECQ
iterator to the filesystem, so it isn't going to see ITER_KVEC, ITER_BVEC
or ITER_FOLIOQ iterators.  So remove that code.

Signed-off-by: David Howells <dhowells at redhat.com>
cc: Steve French <sfrench at samba.org>
cc: Paulo Alcantara <pc at manguebit.org>
cc: Shyam Prasad N <sprasad at microsoft.com>
cc: Tom Talpey <tom at talpey.com>
cc: linux-cifs at vger.kernel.org
cc: netfs at lists.linux.dev
cc: linux-fsdevel at vger.kernel.org
---
 fs/smb/client/smbdirect.c | 165 --------------------------------------
 1 file changed, 165 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index 0c6262010cd2..682df21c5ad2 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -3142,162 +3142,6 @@ static bool smb_set_sge(struct smb_extract_to_rdma *rdma,
 	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 memory fragments from a BVECQ-class iterator and add them to an RDMA
  * list.  The folios are not pinned.
@@ -3373,15 +3217,6 @@ static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len,
 	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;
 	case ITER_BVECQ:
 		ret = smb_extract_bvecq_to_rdma(iter, rdma, len);
 		break;