fs/9p: call vmtruncate before setattr 9p opeation

We need to call vmtruncate before 9p setattr operation, otherwise we
could write back some dirty pages between setattr with ATTR_SIZE and vmtruncate
causing some truncated pages to be written back to server

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, 8 insertions, 11 deletions

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 524d255a5748..2555776920ad 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -993,18 +993,16 @@ static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
                 if (iattr->ia_valid & ATTR_GID)
                         wstat.n_gid = iattr->ia_gid;
         }
-
-        retval = p9_client_wstat(fid, &wstat);
-        if (retval < 0)
-                return retval;
-
-        v9fs_invalidate_inode_attr(dentry->d_inode);
         if ((iattr->ia_valid & ATTR_SIZE) &&
             iattr->ia_size != i_size_read(dentry->d_inode)) {
                 retval = vmtruncate(dentry->d_inode, iattr->ia_size);
                 if (retval)
                         return retval;
         }
+        retval = p9_client_wstat(fid, &wstat);
+        if (retval < 0)
+                return retval;
+        v9fs_invalidate_inode_attr(dentry->d_inode);
 
         setattr_copy(dentry->d_inode, iattr);
         mark_inode_dirty(dentry->d_inode);
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 81bb4c2a0b82..bcd0ee2e549a 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -453,17 +453,16 @@ int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
         if (IS_ERR(fid))
                 return PTR_ERR(fid);
 
-        retval = p9_client_setattr(fid, &p9attr);
-        if (retval < 0)
-                return retval;
-
-        v9fs_invalidate_inode_attr(dentry->d_inode);
         if ((iattr->ia_valid & ATTR_SIZE) &&
             iattr->ia_size != i_size_read(dentry->d_inode)) {
                 retval = vmtruncate(dentry->d_inode, iattr->ia_size);
                 if (retval)
                         return retval;
         }
+        retval = p9_client_setattr(fid, &p9attr);
+        if (retval < 0)
+                return retval;
+        v9fs_invalidate_inode_attr(dentry->d_inode);
 
         setattr_copy(dentry->d_inode, iattr);
         mark_inode_dirty(dentry->d_inode);