[PATCH] cifs: convert readpages_fill_pages to use iter

[Steve French <smfrench@xxxxxxxxx>]

(Another patch to make conversion to new netfs interfaces easier)

Optimize read_page_from_socket by using an iov_iter

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
 fs/cifs/cifsglob.h  |  1 +
 fs/cifs/cifsproto.h |  3 +++
 fs/cifs/connect.c   | 16 ++++++++++++++++
 fs/cifs/file.c      |  3 +--
 4 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 50fcb65920e8..73f80cc38316 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1301,6 +1301,7 @@ struct cifs_readdata {
  int (*copy_into_pages)(struct TCP_Server_Info *server,
  struct cifs_readdata *rdata,
  struct iov_iter *iter);
+ struct iov_iter iter;
  struct kvec iov[2];
  struct TCP_Server_Info *server;
 #ifdef CONFIG_CIFS_SMB_DIRECT
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 75ce6f742b8d..64eb5c817712 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -239,6 +239,9 @@ extern int cifs_read_page_from_socket(struct
TCP_Server_Info *server,
  unsigned int page_offset,
  unsigned int to_read);
 extern int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb);
+extern int cifs_read_iter_from_socket(struct TCP_Server_Info *server,
+       struct iov_iter *iter,
+       unsigned int to_read);
 extern int cifs_match_super(struct super_block *, void *);
 extern int cifs_mount(struct cifs_sb_info *cifs_sb, struct
smb3_fs_context *ctx);
 extern void cifs_umount(struct cifs_sb_info *);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 943f4eba027d..7c8db233fba4 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -585,6 +585,22 @@ cifs_read_page_from_socket(struct TCP_Server_Info
*server, struct page *page,
  return cifs_readv_from_socket(server, &smb_msg);
 }

+int
+cifs_read_iter_from_socket(struct TCP_Server_Info *server, struct
iov_iter *iter,
+    unsigned int to_read)
+{
+ struct msghdr smb_msg;
+ int ret;
+
+ smb_msg.msg_iter = *iter;
+ if (smb_msg.msg_iter.count > to_read)
+ smb_msg.msg_iter.count = to_read;
+ ret = cifs_readv_from_socket(server, &smb_msg);
+ if (ret > 0)
+ iov_iter_advance(iter, ret);
+ return ret;
+}
+
 static bool
 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 {
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 6d001905c8e5..4b8c1ac58f00 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -4261,8 +4261,7 @@ readpages_fill_pages(struct TCP_Server_Info *server,
  result = n;
 #endif
  else
- result = cifs_read_page_from_socket(
- server, page, page_offset, n);
+ result = cifs_read_iter_from_socket(server, &rdata->iter, n);
  if (result < 0)
  break;


-- 
Thanks,

Steve

From a4c963803ddf8c17f36913089965f0348e536330 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@xxxxxxxxxx>
Date: Thu, 4 Feb 2021 00:44:04 -0600
Subject: [PATCH] cifs: convert readpages_fill_pages to use iter

Optimize read_page_from_socket by using an iov_iter

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
 fs/cifs/cifsglob.h  |  1 +
 fs/cifs/cifsproto.h |  3 +++
 fs/cifs/connect.c   | 16 ++++++++++++++++
 fs/cifs/file.c      |  3 +--
 4 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 50fcb65920e8..73f80cc38316 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1301,6 +1301,7 @@ struct cifs_readdata {
 	int (*copy_into_pages)(struct TCP_Server_Info *server,
 				struct cifs_readdata *rdata,
 				struct iov_iter *iter);
+	struct iov_iter			iter;
 	struct kvec			iov[2];
 	struct TCP_Server_Info		*server;
 #ifdef CONFIG_CIFS_SMB_DIRECT
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 75ce6f742b8d..64eb5c817712 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -239,6 +239,9 @@ extern int cifs_read_page_from_socket(struct TCP_Server_Info *server,
 					unsigned int page_offset,
 					unsigned int to_read);
 extern int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb);
+extern int cifs_read_iter_from_socket(struct TCP_Server_Info *server,
+				      struct iov_iter *iter,
+				      unsigned int to_read);
 extern int cifs_match_super(struct super_block *, void *);
 extern int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx);
 extern void cifs_umount(struct cifs_sb_info *);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 943f4eba027d..7c8db233fba4 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -585,6 +585,22 @@ cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 	return cifs_readv_from_socket(server, &smb_msg);
 }
 
+int
+cifs_read_iter_from_socket(struct TCP_Server_Info *server, struct iov_iter *iter,
+			   unsigned int to_read)
+{
+	struct msghdr smb_msg;
+	int ret;
+
+	smb_msg.msg_iter = *iter;
+	if (smb_msg.msg_iter.count > to_read)
+		smb_msg.msg_iter.count = to_read;
+	ret = cifs_readv_from_socket(server, &smb_msg);
+	if (ret > 0)
+		iov_iter_advance(iter, ret);
+	return ret;
+}
+
 static bool
 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 {
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 6d001905c8e5..4b8c1ac58f00 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -4261,8 +4261,7 @@ readpages_fill_pages(struct TCP_Server_Info *server,
 			result = n;
 #endif
 		else
-			result = cifs_read_page_from_socket(
-					server, page, page_offset, n);
+			result = cifs_read_iter_from_socket(server, &rdata->iter, n);
 		if (result < 0)
 			break;
 
-- 
2.27.0