diff mbox

[6/6] cifs: don't bother with kmap on read_pages side

Message ID 20160409205304.GL25498@ZenIV.linux.org.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Al Viro April 9, 2016, 8:53 p.m. UTC 
just do ITER_BVEC recvmsg

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/cifs/cifsproto.h |  7 +++---
 fs/cifs/connect.c   | 65 ++++++++++++++++++++++++++++-------------------------
 fs/cifs/file.c      | 53 ++++++++++++++-----------------------------
 3 files changed, 55 insertions(+), 70 deletions(-)

Comments

Jeff Layton April 19, 2016, 6:24 p.m. UTC | #1 
On Sat, 2016-04-09 at 21:53 +0100, Al Viro wrote:
> just do ITER_BVEC recvmsg
> 
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
>  fs/cifs/cifsproto.h |  7 +++---
>  fs/cifs/connect.c   | 65 ++++++++++++++++++++++++++++-------------------------
>  fs/cifs/file.c      | 53 ++++++++++++++-----------------------------
>  3 files changed, 55 insertions(+), 70 deletions(-)
> 
> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
> index 7d5f53a..0f9a6bc 100644
> --- a/fs/cifs/cifsproto.h
> +++ b/fs/cifs/cifsproto.h
> @@ -179,10 +179,9 @@ extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
>  
>  extern void dequeue_mid(struct mid_q_entry *mid, bool malformed);
>  extern int cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
> -		     unsigned int to_read);
> -extern int cifs_readv_from_socket(struct TCP_Server_Info *server,
> -		struct kvec *iov_orig, unsigned int nr_segs,
> -		unsigned int to_read);
> +			         unsigned int to_read);
> +extern int cifs_read_page_from_socket(struct TCP_Server_Info *server,
> +				      struct page *page, unsigned int to_read);
>  extern void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
>  			       struct cifs_sb_info *cifs_sb);
>  extern int cifs_match_super(struct super_block *, void *);
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index eb42665..e33c5e0 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -501,39 +501,34 @@ server_unresponsive(struct TCP_Server_Info *server)
>  	return false;
>  }
>  
> -int
> -cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
> -		       unsigned int nr_segs, unsigned int to_read)
> +static int
> +cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
>  {
>  	int length = 0;
>  	int total_read;
> -	struct msghdr smb_msg;
>  
> -	smb_msg.msg_control = NULL;
> -	smb_msg.msg_controllen = 0;
> -	iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC,
> -		      iov_orig, nr_segs, to_read);
> +	smb_msg->msg_control = NULL;
> +	smb_msg->msg_controllen = 0;
>  
> -	for (total_read = 0; msg_data_left(&smb_msg); total_read += length) {
> +	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
>  		try_to_freeze();
>  
> -		if (server_unresponsive(server)) {
> -			total_read = -ECONNABORTED;
> -			break;
> -		}
> +		if (server_unresponsive(server))
> +			return -ECONNABORTED;
>  
> -		length = sock_recvmsg(server->ssocket, &smb_msg, 0);
> +		length = sock_recvmsg(server->ssocket, smb_msg, 0);
>  
> -		if (server->tcpStatus == CifsExiting) {
> -			total_read = -ESHUTDOWN;
> -			break;
> -		} else if (server->tcpStatus == CifsNeedReconnect) {
> +		if (server->tcpStatus == CifsExiting)
> +			return -ESHUTDOWN;
> +
> +		if (server->tcpStatus == CifsNeedReconnect) {
>  			cifs_reconnect(server);
> -			total_read = -ECONNABORTED;
> -			break;
> -		} else if (length == -ERESTARTSYS ||
> -			   length == -EAGAIN ||
> -			   length == -EINTR) {
> +			return -ECONNABORTED;
> +		}
> +
> +		if (length == -ERESTARTSYS ||
> +		    length == -EAGAIN ||
> +		    length == -EINTR) {
>  			/*
>  			 * Minimum sleep to prevent looping, allowing socket
>  			 * to clear and app threads to set tcpStatus
> @@ -542,11 +537,12 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
>  			usleep_range(1000, 2000);
>  			length = 0;
>  			continue;
> -		} else if (length <= 0) {
> +		}
> +
> +		if (length <= 0) {
>  			cifs_dbg(FYI, "Received no data or error: %d\n", length);
>  			cifs_reconnect(server);
> -			total_read = -ECONNABORTED;
> -			break;
> +			return -ECONNABORTED;
>  		}
>  	}
>  	return total_read;
> @@ -556,12 +552,21 @@ int
>  cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
>  		      unsigned int to_read)
>  {
> -	struct kvec iov;
> +	struct msghdr smb_msg;
> +	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
> +	iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC, &iov, 1, to_read);
>  
> -	iov.iov_base = buf;
> -	iov.iov_len = to_read;
> +	return cifs_readv_from_socket(server, &smb_msg);
> +}
>  
> -	return cifs_readv_from_socket(server, &iov, 1, to_read);
> +int
> +cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
> +		      unsigned int to_read)
> +{
> +	struct msghdr smb_msg;
> +	struct bio_vec bv = {.bv_page = page, .bv_len = to_read};
> +	iov_iter_bvec(&smb_msg.msg_iter, READ | ITER_BVEC, &bv, 1, to_read);
> +	return cifs_readv_from_socket(server, &smb_msg);
>  }
>  
>  static bool
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index ff882ae..0f71867 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -2855,39 +2855,31 @@ cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
>  	int result = 0;
>  	unsigned int i;
>  	unsigned int nr_pages = rdata->nr_pages;
> -	struct kvec iov;
>  
>  	rdata->got_bytes = 0;
>  	rdata->tailsz = PAGE_SIZE;
>  	for (i = 0; i < nr_pages; i++) {
>  		struct page *page = rdata->pages[i];
> +		size_t n;
>  
> -		if (len >= PAGE_SIZE) {
> -			/* enough data to fill the page */
> -			iov.iov_base = kmap(page);
> -			iov.iov_len = PAGE_SIZE;
> -			cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
> -				 i, iov.iov_base, iov.iov_len);
> -			len -= PAGE_SIZE;
> -		} else if (len > 0) {
> -			/* enough for partial page, fill and zero the rest */
> -			iov.iov_base = kmap(page);
> -			iov.iov_len = len;
> -			cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
> -				 i, iov.iov_base, iov.iov_len);
> -			memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
> -			rdata->tailsz = len;
> -			len = 0;
> -		} else {
> +		if (len <= 0) {
>  			/* no need to hold page hostage */
>  			rdata->pages[i] = NULL;
>  			rdata->nr_pages--;
>  			put_page(page);
>  			continue;
>  		}
> -
> -		result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
> -		kunmap(page);
> +		n = len;
> +		if (len >= PAGE_SIZE) {
> +			/* enough data to fill the page */
> +			n = PAGE_SIZE;
> +			len -= n;
> +		} else {
> +			zero_user(page, len, PAGE_SIZE - len);
> +			rdata->tailsz = len;
> +			len = 0;
> +		}
> +		result = cifs_read_page_from_socket(server, page, n);
>  		if (result < 0)
>  			break;
>  
> @@ -3303,7 +3295,6 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
>  	u64 eof;
>  	pgoff_t eof_index;
>  	unsigned int nr_pages = rdata->nr_pages;
> -	struct kvec iov;
>  
>  	/* determine the eof that the server (probably) has */
>  	eof = CIFS_I(rdata->mapping->host)->server_eof;
> @@ -3314,23 +3305,14 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
>  	rdata->tailsz = PAGE_CACHE_SIZE;
>  	for (i = 0; i < nr_pages; i++) {
>  		struct page *page = rdata->pages[i];
> +		size_t n = PAGE_CACHE_SIZE;
>  
>  		if (len >= PAGE_CACHE_SIZE) {
> -			/* enough data to fill the page */
> -			iov.iov_base = kmap(page);
> -			iov.iov_len = PAGE_CACHE_SIZE;
> -			cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
> -				 i, page->index, iov.iov_base, iov.iov_len);
>  			len -= PAGE_CACHE_SIZE;
>  		} else if (len > 0) {
>  			/* enough for partial page, fill and zero the rest */
> -			iov.iov_base = kmap(page);
> -			iov.iov_len = len;
> -			cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
> -				 i, page->index, iov.iov_base, iov.iov_len);
> -			memset(iov.iov_base + len,
> -				'\0', PAGE_CACHE_SIZE - len);
> -			rdata->tailsz = len;
> +			zero_user(page, len, PAGE_CACHE_SIZE - len);
> +			n = rdata->tailsz = len;
>  			len = 0;
>  		} else if (page->index > eof_index) {
>  			/*
> @@ -3360,8 +3342,7 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
>  			continue;
>  		}
>  
> -		result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
> -		kunmap(page);
> +		result = cifs_read_page_from_socket(server, page, n);
>  		if (result < 0)
>  			break;
>  

Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
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diff mbox

Patch

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 7d5f53a..0f9a6bc 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -179,10 +179,9 @@  extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
 
 extern void dequeue_mid(struct mid_q_entry *mid, bool malformed);
 extern int cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
-		     unsigned int to_read);
-extern int cifs_readv_from_socket(struct TCP_Server_Info *server,
-		struct kvec *iov_orig, unsigned int nr_segs,
-		unsigned int to_read);
+			         unsigned int to_read);
+extern int cifs_read_page_from_socket(struct TCP_Server_Info *server,
+				      struct page *page, unsigned int to_read);
 extern void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
 			       struct cifs_sb_info *cifs_sb);
 extern int cifs_match_super(struct super_block *, void *);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index eb42665..e33c5e0 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -501,39 +501,34 @@  server_unresponsive(struct TCP_Server_Info *server)
 	return false;
 }
 
-int
-cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
-		       unsigned int nr_segs, unsigned int to_read)
+static int
+cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 {
 	int length = 0;
 	int total_read;
-	struct msghdr smb_msg;
 
-	smb_msg.msg_control = NULL;
-	smb_msg.msg_controllen = 0;
-	iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC,
-		      iov_orig, nr_segs, to_read);
+	smb_msg->msg_control = NULL;
+	smb_msg->msg_controllen = 0;
 
-	for (total_read = 0; msg_data_left(&smb_msg); total_read += length) {
+	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 		try_to_freeze();
 
-		if (server_unresponsive(server)) {
-			total_read = -ECONNABORTED;
-			break;
-		}
+		if (server_unresponsive(server))
+			return -ECONNABORTED;
 
-		length = sock_recvmsg(server->ssocket, &smb_msg, 0);
+		length = sock_recvmsg(server->ssocket, smb_msg, 0);
 
-		if (server->tcpStatus == CifsExiting) {
-			total_read = -ESHUTDOWN;
-			break;
-		} else if (server->tcpStatus == CifsNeedReconnect) {
+		if (server->tcpStatus == CifsExiting)
+			return -ESHUTDOWN;
+
+		if (server->tcpStatus == CifsNeedReconnect) {
 			cifs_reconnect(server);
-			total_read = -ECONNABORTED;
-			break;
-		} else if (length == -ERESTARTSYS ||
-			   length == -EAGAIN ||
-			   length == -EINTR) {
+			return -ECONNABORTED;
+		}
+
+		if (length == -ERESTARTSYS ||
+		    length == -EAGAIN ||
+		    length == -EINTR) {
 			/*
 			 * Minimum sleep to prevent looping, allowing socket
 			 * to clear and app threads to set tcpStatus
@@ -542,11 +537,12 @@  cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
 			usleep_range(1000, 2000);
 			length = 0;
 			continue;
-		} else if (length <= 0) {
+		}
+
+		if (length <= 0) {
 			cifs_dbg(FYI, "Received no data or error: %d\n", length);
 			cifs_reconnect(server);
-			total_read = -ECONNABORTED;
-			break;
+			return -ECONNABORTED;
 		}
 	}
 	return total_read;
@@ -556,12 +552,21 @@  int
 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 		      unsigned int to_read)
 {
-	struct kvec iov;
+	struct msghdr smb_msg;
+	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
+	iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC, &iov, 1, to_read);
 
-	iov.iov_base = buf;
-	iov.iov_len = to_read;
+	return cifs_readv_from_socket(server, &smb_msg);
+}
 
-	return cifs_readv_from_socket(server, &iov, 1, to_read);
+int
+cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
+		      unsigned int to_read)
+{
+	struct msghdr smb_msg;
+	struct bio_vec bv = {.bv_page = page, .bv_len = to_read};
+	iov_iter_bvec(&smb_msg.msg_iter, READ | ITER_BVEC, &bv, 1, to_read);
+	return cifs_readv_from_socket(server, &smb_msg);
 }
 
 static bool
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index ff882ae..0f71867 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2855,39 +2855,31 @@  cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
 	int result = 0;
 	unsigned int i;
 	unsigned int nr_pages = rdata->nr_pages;
-	struct kvec iov;
 
 	rdata->got_bytes = 0;
 	rdata->tailsz = PAGE_SIZE;
 	for (i = 0; i < nr_pages; i++) {
 		struct page *page = rdata->pages[i];
+		size_t n;
 
-		if (len >= PAGE_SIZE) {
-			/* enough data to fill the page */
-			iov.iov_base = kmap(page);
-			iov.iov_len = PAGE_SIZE;
-			cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
-				 i, iov.iov_base, iov.iov_len);
-			len -= PAGE_SIZE;
-		} else if (len > 0) {
-			/* enough for partial page, fill and zero the rest */
-			iov.iov_base = kmap(page);
-			iov.iov_len = len;
-			cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
-				 i, iov.iov_base, iov.iov_len);
-			memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
-			rdata->tailsz = len;
-			len = 0;
-		} else {
+		if (len <= 0) {
 			/* no need to hold page hostage */
 			rdata->pages[i] = NULL;
 			rdata->nr_pages--;
 			put_page(page);
 			continue;
 		}
-
-		result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
-		kunmap(page);
+		n = len;
+		if (len >= PAGE_SIZE) {
+			/* enough data to fill the page */
+			n = PAGE_SIZE;
+			len -= n;
+		} else {
+			zero_user(page, len, PAGE_SIZE - len);
+			rdata->tailsz = len;
+			len = 0;
+		}
+		result = cifs_read_page_from_socket(server, page, n);
 		if (result < 0)
 			break;
 
@@ -3303,7 +3295,6 @@  cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
 	u64 eof;
 	pgoff_t eof_index;
 	unsigned int nr_pages = rdata->nr_pages;
-	struct kvec iov;
 
 	/* determine the eof that the server (probably) has */
 	eof = CIFS_I(rdata->mapping->host)->server_eof;
@@ -3314,23 +3305,14 @@  cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
 	rdata->tailsz = PAGE_CACHE_SIZE;
 	for (i = 0; i < nr_pages; i++) {
 		struct page *page = rdata->pages[i];
+		size_t n = PAGE_CACHE_SIZE;
 
 		if (len >= PAGE_CACHE_SIZE) {
-			/* enough data to fill the page */
-			iov.iov_base = kmap(page);
-			iov.iov_len = PAGE_CACHE_SIZE;
-			cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
-				 i, page->index, iov.iov_base, iov.iov_len);
 			len -= PAGE_CACHE_SIZE;
 		} else if (len > 0) {
 			/* enough for partial page, fill and zero the rest */
-			iov.iov_base = kmap(page);
-			iov.iov_len = len;
-			cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
-				 i, page->index, iov.iov_base, iov.iov_len);
-			memset(iov.iov_base + len,
-				'\0', PAGE_CACHE_SIZE - len);
-			rdata->tailsz = len;
+			zero_user(page, len, PAGE_CACHE_SIZE - len);
+			n = rdata->tailsz = len;
 			len = 0;
 		} else if (page->index > eof_index) {
 			/*
@@ -3360,8 +3342,7 @@  cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
 			continue;
 		}
 
-		result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
-		kunmap(page);
+		result = cifs_read_page_from_socket(server, page, n);
 		if (result < 0)
 			break;