From 1b65007e9870e0021397b548e8cd6bbc584f9152 Mon Sep 17 00:00:00 2001
From: Dmitry Monakhov <dmonakhov@openvz.org>
Date: Sat, 29 Sep 2012 00:56:15 -0400
Subject: ext4: endless truncate due to nonlocked dio readers
If we have enough aggressive DIO readers, truncate and other dio
waiters will wait forever inside inode_dio_wait(). It is reasonable
to disable nonlock DIO read optimization during truncate.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
fs/ext4/inode.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
(limited to 'fs')
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 0bfc6333146..05ab70dd5c6 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4333,9 +4333,14 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
if (attr->ia_valid & ATTR_SIZE) {
if (attr->ia_size != i_size_read(inode)) {
truncate_setsize(inode, attr->ia_size);
- /* Inode size will be reduced, wait for dio in flight */
- if (orphan)
+ /* Inode size will be reduced, wait for dio in flight.
+ * Temporarily disable dioread_nolock to prevent
+ * livelock. */
+ if (orphan) {
+ ext4_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
+ ext4_inode_resume_unlocked_dio(inode);
+ }
}
ext4_truncate(inode);
}
--
cgit v1.2.3-70-g09d2