[RFC PATCH 08/17] cifs: Use a bvecq for buffering instead of a folioq

[David Howells <dhowells@redhat.com>]

Use a bvecq for internal buffering for crypto purposes instead of a folioq
so that the latter can be phased out.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Paulo Alcantara <pc@manguebit.org>
cc: Matthew Wilcox <willy@infradead.org>
cc: Christoph Hellwig <hch@infradead.org>
cc: Steve French <sfrench@samba.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
---
 fs/smb/client/cifsglob.h |  2 +-
 fs/smb/client/smb2ops.c  | 70 +++++++++++++++++++---------------------
 2 files changed, 34 insertions(+), 38 deletions(-)

diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 080ea601c209..12202d9537e0 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -290,7 +290,7 @@ struct smb_rqst {
 	struct kvec	*rq_iov;	/* array of kvecs */
 	unsigned int	rq_nvec;	/* number of kvecs in array */
 	struct iov_iter	rq_iter;	/* Data iterator */
-	struct folio_queue *rq_buffer;	/* Buffer for encryption */
+	struct bvecq	*rq_buffer;	/* Buffer for encryption */
 };
 
 struct mid_q_entry;
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index fea9a35caa57..76baf21404df 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -4517,19 +4517,17 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst,
 }
 
 /*
- * Copy data from an iterator to the folios in a folio queue buffer.
+ * Copy data from an iterator to the pages in a bvec queue buffer.
  */
-static bool cifs_copy_iter_to_folioq(struct iov_iter *iter, size_t size,
-				     struct folio_queue *buffer)
+static bool cifs_copy_iter_to_bvecq(struct iov_iter *iter, size_t size,
+				    struct bvecq *buffer)
 {
 	for (; buffer; buffer = buffer->next) {
-		for (int s = 0; s < folioq_count(buffer); s++) {
-			struct folio *folio = folioq_folio(buffer, s);
-			size_t part = folioq_folio_size(buffer, s);
+		for (int s = 0; s < buffer->nr_segs; s++) {
+			struct bio_vec *bv = &buffer->bv[s];
+			size_t part = umin(bv->bv_len, size);
 
-			part = umin(part, size);
-
-			if (copy_folio_from_iter(folio, 0, part, iter) != part)
+			if (copy_page_from_iter(bv->bv_page, 0, part, iter) != part)
 				return false;
 			size -= part;
 		}
@@ -4541,7 +4539,7 @@ void
 smb3_free_compound_rqst(int num_rqst, struct smb_rqst *rqst)
 {
 	for (int i = 0; i < num_rqst; i++)
-		netfs_free_folioq_buffer(rqst[i].rq_buffer);
+		netfs_free_bvecq_buffer(rqst[i].rq_buffer);
 }
 
 /*
@@ -4568,7 +4566,7 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, int num_rqst,
 	for (int i = 1; i < num_rqst; i++) {
 		struct smb_rqst *old = &old_rq[i - 1];
 		struct smb_rqst *new = &new_rq[i];
-		struct folio_queue *buffer = NULL;
+		struct bvecq *buffer = NULL;
 		size_t size = iov_iter_count(&old->rq_iter);
 
 		orig_len += smb_rqst_len(server, old);
@@ -4576,17 +4574,16 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, int num_rqst,
 		new->rq_nvec = old->rq_nvec;
 
 		if (size > 0) {
-			size_t cur_size = 0;
-			rc = netfs_alloc_folioq_buffer(NULL, &buffer, &cur_size,
-						       size, GFP_NOFS);
-			if (rc < 0)
+			rc = -ENOMEM;
+			buffer = netfs_alloc_bvecq_buffer(size, 0, GFP_NOFS);
+			if (!buffer)
 				goto err_free;
 
 			new->rq_buffer = buffer;
-			iov_iter_folio_queue(&new->rq_iter, ITER_SOURCE,
-					     buffer, 0, 0, size);
+			iov_iter_bvec_queue(&new->rq_iter, ITER_SOURCE,
+					    buffer, 0, 0, size);
 
-			if (!cifs_copy_iter_to_folioq(&old->rq_iter, size, buffer)) {
+			if (!cifs_copy_iter_to_bvecq(&old->rq_iter, size, buffer)) {
 				rc = smb_EIO1(smb_eio_trace_tx_copy_iter_to_buf, size);
 				goto err_free;
 			}
@@ -4676,16 +4673,15 @@ decrypt_raw_data(struct TCP_Server_Info *server, char *buf,
 }
 
 static int
-cifs_copy_folioq_to_iter(struct folio_queue *folioq, size_t data_size,
-			 size_t skip, struct iov_iter *iter)
+cifs_copy_bvecq_to_iter(struct bvecq *bq, size_t data_size,
+			size_t skip, struct iov_iter *iter)
 {
-	for (; folioq; folioq = folioq->next) {
-		for (int s = 0; s < folioq_count(folioq); s++) {
-			struct folio *folio = folioq_folio(folioq, s);
-			size_t fsize = folio_size(folio);
-			size_t n, len = umin(fsize - skip, data_size);
+	for (; bq; bq = bq->next) {
+		for (int s = 0; s < bq->nr_segs; s++) {
+			struct bio_vec *bv = &bq->bv[s];
+			size_t n, len = umin(bv->bv_len - skip, data_size);
 
-			n = copy_folio_to_iter(folio, skip, len, iter);
+			n = copy_page_to_iter(bv->bv_page, bv->bv_offset + skip, len, iter);
 			if (n != len) {
 				cifs_dbg(VFS, "%s: something went wrong\n", __func__);
 				return smb_EIO2(smb_eio_trace_rx_copy_to_iter,
@@ -4701,7 +4697,7 @@ cifs_copy_folioq_to_iter(struct folio_queue *folioq, size_t data_size,
 
 static int
 handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
-		 char *buf, unsigned int buf_len, struct folio_queue *buffer,
+		 char *buf, unsigned int buf_len, struct bvecq *buffer,
 		 unsigned int buffer_len, bool is_offloaded)
 {
 	unsigned int data_offset;
@@ -4810,8 +4806,8 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
 		}
 
 		/* Copy the data to the output I/O iterator. */
-		rdata->result = cifs_copy_folioq_to_iter(buffer, buffer_len,
-							 cur_off, &rdata->subreq.io_iter);
+		rdata->result = cifs_copy_bvecq_to_iter(buffer, buffer_len,
+							cur_off, &rdata->subreq.io_iter);
 		if (rdata->result != 0) {
 			if (is_offloaded)
 				mid->mid_state = MID_RESPONSE_MALFORMED;
@@ -4849,7 +4845,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
 struct smb2_decrypt_work {
 	struct work_struct decrypt;
 	struct TCP_Server_Info *server;
-	struct folio_queue *buffer;
+	struct bvecq *buffer;
 	char *buf;
 	unsigned int len;
 };
@@ -4863,7 +4859,7 @@ static void smb2_decrypt_offload(struct work_struct *work)
 	struct mid_q_entry *mid;
 	struct iov_iter iter;
 
-	iov_iter_folio_queue(&iter, ITER_DEST, dw->buffer, 0, 0, dw->len);
+	iov_iter_bvec_queue(&iter, ITER_DEST, dw->buffer, 0, 0, dw->len);
 	rc = decrypt_raw_data(dw->server, dw->buf, dw->server->vals->read_rsp_size,
 			      &iter, true);
 	if (rc) {
@@ -4912,7 +4908,7 @@ static void smb2_decrypt_offload(struct work_struct *work)
 	}
 
 free_pages:
-	netfs_free_folioq_buffer(dw->buffer);
+	netfs_free_bvecq_buffer(dw->buffer);
 	cifs_small_buf_release(dw->buf);
 	kfree(dw);
 }
@@ -4950,12 +4946,12 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid,
 	dw->len = len;
 	len = round_up(dw->len, PAGE_SIZE);
 
-	size_t cur_size = 0;
-	rc = netfs_alloc_folioq_buffer(NULL, &dw->buffer, &cur_size, len, GFP_NOFS);
-	if (rc < 0)
+	rc = -ENOMEM;
+	dw->buffer = netfs_alloc_bvecq_buffer(len, 0, GFP_NOFS);
+	if (!dw->buffer)
 		goto discard_data;
 
-	iov_iter_folio_queue(&iter, ITER_DEST, dw->buffer, 0, 0, len);
+	iov_iter_bvec_queue(&iter, ITER_DEST, dw->buffer, 0, 0, len);
 
 	/* Read the data into the buffer and clear excess bufferage. */
 	rc = cifs_read_iter_from_socket(server, &iter, dw->len);
@@ -5013,7 +5009,7 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid,
 	}
 
 free_pages:
-	netfs_free_folioq_buffer(dw->buffer);
+	netfs_free_bvecq_buffer(dw->buffer);
 free_dw:
 	kfree(dw);
 	return rc;