4 files changed, 57 insertions, 9 deletions

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index b6b85cf01e0d..24eb01087b6d 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -234,7 +234,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	if (!v9ses->clnt->dotu)
 		v9ses->flags &= ~V9FS_EXTENDED;
 
-	v9ses->maxdata = v9ses->clnt->msize;
+	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 
 	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
 	if (!v9fs_extended(v9ses) &&
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index 57997fa14e69..046cff377f10 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -52,3 +52,5 @@ int v9fs_file_open(struct inode *inode, struct file *file);
 void v9fs_inode2stat(struct inode *inode, struct p9_stat *stat);
 void v9fs_dentry_release(struct dentry *);
 int v9fs_uflags2omode(int uflags, int extended);
+
+ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64);
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 97d3aed57983..6fcb1e7095cf 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -38,7 +38,6 @@
 
 #include "v9fs.h"
 #include "v9fs_vfs.h"
-#include "fid.h"
 
 /**
  * v9fs_vfs_readpage - read an entire page in from 9P
@@ -53,14 +52,12 @@ static int v9fs_vfs_readpage(struct file *filp, struct page *page)
 	int retval;
 	loff_t offset;
 	char *buffer;
-	struct p9_fid *fid;
 
 	P9_DPRINTK(P9_DEBUG_VFS, "\n");
-	fid = filp->private_data;
 	buffer = kmap(page);
 	offset = page_offset(page);
 
-	retval = p9_client_readn(fid, buffer, offset, PAGE_CACHE_SIZE);
+	retval = v9fs_file_readn(filp, buffer, NULL, offset, PAGE_CACHE_SIZE);
 	if (retval < 0)
 		goto done;
 
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 3819a195de8f..4d6d7657fb75 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -120,23 +120,72 @@ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
 }
 
 /**
- * v9fs_file_read - read from a file
+ * v9fs_file_readn - read from a file
  * @filp: file pointer to read
  * @data: data buffer to read data into
+ * @udata: user data buffer to read data into
  * @count: size of buffer
  * @offset: offset at which to read data
  *
  */
+
+ssize_t
+v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
+	       u64 offset)
+{
+	int n, total;
+	struct p9_fid *fid = filp->private_data;
+
+	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
+					(long long unsigned) offset, count);
+
+	n = 0;
+	total = 0;
+	do {
+		n = p9_client_read(fid, data, udata, offset, count);
+		if (n <= 0)
+			break;
+
+		if (data)
+			data += n;
+		if (udata)
+			udata += n;
+
+		offset += n;
+		count -= n;
+		total += n;
+	} while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ));
+
+	if (n < 0)
+		total = n;
+
+	return total;
+}
+
+/**
+ * v9fs_file_read - read from a file
+ * @filp: file pointer to read
+ * @udata: user data buffer to read data into
+ * @count: size of buffer
+ * @offset: offset at which to read data
+ *
+ */
+
 static ssize_t
-v9fs_file_read(struct file *filp, char __user * data, size_t count,
+v9fs_file_read(struct file *filp, char __user *udata, size_t count,
 	       loff_t * offset)
 {
 	int ret;
 	struct p9_fid *fid;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "\n");
+	P9_DPRINTK(P9_DEBUG_VFS, "count %d offset %lld\n", count, *offset);
 	fid = filp->private_data;
-	ret = p9_client_read(fid, NULL, data, *offset, count);
+
+	if (count > (fid->clnt->msize - P9_IOHDRSZ))
+		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
+	else
+		ret = p9_client_read(fid, NULL, udata, *offset, count);
+
 	if (ret > 0)
 		*offset += ret;