From: Andrey Vagin <avagin@openvz.org>
Date: Fri, 24 Jun 2016 21:50:27 +0000 (-0700)
Subject: autofs: don't get stuck in a loop if vfs_write() returns an error
X-Git-Tag: v4.7-rc5~11^2~1
X-Git-Url: http://git.cascardo.eti.br/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=5a9294e5c535deab69831076af15cd35e1c95f8b

autofs: don't get stuck in a loop if vfs_write() returns an error

__vfs_write() returns a negative value in a error case.

Link: http://lkml.kernel.org/r/20160616083108.6278.65815.stgit@pluto.themaw.net
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 0146d911f468..631f1554c87b 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -66,11 +66,12 @@ static int autofs4_write(struct autofs_sb_info *sbi,
 	set_fs(KERNEL_DS);
 
 	mutex_lock(&sbi->pipe_mutex);
-	wr = __vfs_write(file, data, bytes, &file->f_pos);
-	while (bytes && wr) {
+	while (bytes) {
+		wr = __vfs_write(file, data, bytes, &file->f_pos);
+		if (wr <= 0)
+			break;
 		data += wr;
 		bytes -= wr;
-		wr = __vfs_write(file, data, bytes, &file->f_pos);
 	}
 	mutex_unlock(&sbi->pipe_mutex);