From: Trond Myklebust <trondmy@gmail.com>
Date: Mon, 6 Jan 2020 15:25:00 -0500
Subject: [PATCH] NFS: Revalidate the file size on a fatal write error
Git-commit: 0df68ced55443243951d02cc497be31fadf28173
Patch-mainline: v5.6
References: git-fixes

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: d2ceb7e57086 ("NFS: Don't use page_file_mapping after removing the page")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/write.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -221,7 +221,15 @@ out:
 /* 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_ATTR;
+	spin_unlock(&inode->i_lock);
 }
 
 /*