NFS: Revalidate the file size on a fatal write error

If we suffer a fatal error upon writing a file, which causes us to
need to revalidate the entire mapping, then we should also revalidate
the file size.

Fixes: d2ceb7e5 ("NFS: Don't use page_file_mapping after removing the page")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/write.c

@@ -243,7 +243,15 @@ static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int c
 /* A writeback failed: mark the page as bad, and invalidate the page cache */
 static void nfs_set_pageerror(struct address_space *mapping)
 {
+	struct inode *inode = mapping->host;
+
 	nfs_zap_mapping(mapping->host, mapping);
+	/* Force file size revalidation */
+	spin_lock(&inode->i_lock);
+	NFS_I(inode)->cache_validity |= NFS_INO_REVAL_FORCED |
+					NFS_INO_REVAL_PAGECACHE |
+					NFS_INO_INVALID_SIZE;
+	spin_unlock(&inode->i_lock);
 }
 
 static void nfs_mapping_set_error(struct page *page, int error)