fs/9p: Add read write helper function

We add read write helper function here which will
be used later by the mmap patch

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

2 files changed, 64 insertions, 42 deletions

diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index e4d5540cbb70..c44aaa8bd2a3 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -64,8 +64,10 @@ void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
 int v9fs_uflags2omode(int uflags, int extended);
 
 ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64);
+ssize_t v9fs_fid_readn(struct p9_fid *, char *, char __user *, u32, u64);
 void v9fs_blank_wstat(struct p9_wstat *wstat);
 int v9fs_vfs_setattr_dotl(struct dentry *, struct iattr *);
 int v9fs_file_fsync_dotl(struct file *filp, int datasync);
-
+ssize_t v9fs_file_write_internal(struct inode *, struct p9_fid *,
+                                 const char __user *, size_t, loff_t *, int);
 #define P9_LOCK_TIMEOUT (30*HZ)
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index ce1eae48a127..6e1e8f43edac 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -323,25 +323,22 @@ out_err:
 }
 
 /**
- * v9fs_file_readn - read from a file
- * @filp: file pointer to read
+ * v9fs_fid_readn - read from a fid
+ * @fid: fid 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,
+v9fs_fid_readn(struct p9_fid *fid, char *data, char __user *udata, u32 count,
                u64 offset)
 {
         int n, total, size;
-        struct p9_fid *fid = filp->private_data;
 
         P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
-                                        (long long unsigned) offset, count);
-
+                   (long long unsigned) offset, count);
         n = 0;
         total = 0;
         size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
@@ -367,6 +364,22 @@ v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
 }
 
 /**
+ * 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)
+{
+        return v9fs_fid_readn(filp->private_data, data, udata, count, offset);
+}
+
+/**
  * v9fs_file_read - read from a file
  * @filp: file pointer to read
  * @udata: user data buffer to read data into
@@ -398,45 +411,21 @@ v9fs_file_read(struct file *filp, char __user *udata, size_t count,
         return ret;
 }
 
-/**
- * v9fs_file_write - write to a file
- * @filp: file pointer to write
- * @data: data buffer to write data from
- * @count: size of buffer
- * @offset: offset at which to write data
- *
- */
-
-static ssize_t
-v9fs_file_write(struct file *filp, const char __user * data,
-                size_t count, loff_t * offset)
+ssize_t
+v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
+                         const char __user *data, size_t count,
+                         loff_t *offset, int invalidate)
 {
-        ssize_t retval;
-        size_t total = 0;
         int n;
-        struct p9_fid *fid;
+        size_t total = 0;
         struct p9_client *clnt;
-        struct inode *inode = filp->f_path.dentry->d_inode;
         loff_t origin = *offset;
         unsigned long pg_start, pg_end;
 
         P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
                 (int)count, (int)*offset);
 
-        fid = filp->private_data;
         clnt = fid->clnt;
-
-        retval = generic_write_checks(filp, &origin, &count, 0);
-        if (retval)
-                goto out;
-
-        retval = -EINVAL;
-        if ((ssize_t) count < 0)
-                goto out;
-        retval = 0;
-        if (!count)
-                goto out;
-
         do {
                 n = p9_client_write(fid, NULL, data+total, origin+total, count);
                 if (n <= 0)
@@ -445,7 +434,7 @@ v9fs_file_write(struct file *filp, const char __user * data,
                 total += n;
         } while (count > 0);
 
-        if (total > 0) {
+        if (invalidate && (total > 0)) {
                 pg_start = origin >> PAGE_CACHE_SHIFT;
                 pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
                 if (inode->i_mapping && inode->i_mapping->nrpages)
@@ -455,11 +444,42 @@ v9fs_file_write(struct file *filp, const char __user * data,
                 i_size_write(inode, i_size_read(inode) + total);
                 inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
         }
-
         if (n < 0)
-                retval = n;
-        else
-                retval = total;
+                return n;
+
+        return total;
+}
+
+/**
+ * v9fs_file_write - write to a file
+ * @filp: file pointer to write
+ * @data: data buffer to write data from
+ * @count: size of buffer
+ * @offset: offset at which to write data
+ *
+ */
+static ssize_t
+v9fs_file_write(struct file *filp, const char __user * data,
+                size_t count, loff_t *offset)
+{
+        ssize_t retval = 0;
+        loff_t origin = *offset;
+
+
+        retval = generic_write_checks(filp, &origin, &count, 0);
+        if (retval)
+                goto out;
+
+        retval = -EINVAL;
+        if ((ssize_t) count < 0)
+                goto out;
+        retval = 0;
+        if (!count)
+                goto out;
+
+        return v9fs_file_write_internal(filp->f_path.dentry->d_inode,
+                                        filp->private_data,
+                                        data, count, offset, 1);
 out:
         return retval;
 }