NFS: Ensure nfs_readpage returns promptly when internal error occurs

commit e0340f16a08d031de54ed91d26f57c9a966a776a upstream.

A previous refactoring of nfs_readpage() might end up calling
wait_on_page_locked_killable() even if readpage_async_filler() failed
with an internal error and pg_error was non-zero (for example, if
nfs_create_request() failed).  In the case of an internal error,
skip over wait_on_page_locked_killable() as this is only needed
when the read is sent and an error occurs during completion handling.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index d2b6dce1f99f70e6b64549dce3c50f5f5a8784a7..08200252e2724a8568937d6ad537e3fda251170d 100644 (file)
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -374,10 +374,10 @@ int nfs_readpage(struct file *file, struct page *page)
                             &nfs_async_read_completion_ops);
 
        ret = readpage_async_filler(&desc, page);
+       if (ret)
+               goto out;
 
-       if (!ret)
-               nfs_pageio_complete_read(&desc.pgio, inode);
-
+       nfs_pageio_complete_read(&desc.pgio, inode);
        ret = desc.pgio.pg_error < 0 ? desc.pgio.pg_error : 0;
        if (!ret) {
                ret = wait_on_page_locked_killable(page);