blob: f4f1fd130f7d4ce11af2af173dcb0452cea71ba6 [file] [log] [blame]
From: Benjamin Coddington <>
Date: Mon, 18 Jul 2016 10:41:57 -0400
Subject: nfs: don't create zero-length requests
commit 149a4fddd0a72d526abbeac0c8deaab03559836a upstream.
NFS doesn't expect requests with wb_bytes set to zero and may make
unexpected decisions about how to handle that request at the page IO layer.
Skip request creation if we won't have any wb_bytes in the request.
Signed-off-by: Benjamin Coddington <>
Signed-off-by: Alexey Dobriyan <>
Reviewed-by: Weston Andros Adamson <>
Signed-off-by: Trond Myklebust <>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <>
fs/nfs/write.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -747,6 +747,9 @@ int nfs_updatepage(struct file *file, st
file->f_path.dentry->, count,
(long long)(page_offset(page) + offset));
+ if (!count)
+ goto out;
/* If we're not using byte range locks, and we know the page
* is up to date, it may be more efficient to extend the write
* to cover the entire page in order to avoid fragmentation
@@ -764,7 +767,7 @@ int nfs_updatepage(struct file *file, st
dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n",
status, (long long)i_size_read(inode));
return status;