[PATCH 08/10] ext4: endless truncate due to nonlocked dio readers V2
From: Dmitry Monakhov <hidden>
Date: 2012-09-24 11:44:42
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
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. Signed-off-by: Dmitry Monakhov <redacted> --- fs/ext4/inode.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 32e9701..d3f86e7 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c@@ -4330,9 +4330,13 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) if (attr->ia_valid & ATTR_SIZE) { if (attr->ia_size != inode->i_size) { 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. + * Temproraly disable unlocked DIO to prevent livelock */ + if (orphan) { + ext4_inode_block_unlocked_dio(inode); inode_dio_wait(inode); + ext4_inode_resume_unlocked_dio(inode); + } } ext4_truncate(inode); }
--
1.7.7.6