From ab7b8a329e12369d58e5fa59ba2e2c90370f12ef Mon Sep 17 00:00:00 2001 From: Dmitry Monakhov Date: Sat, 29 Sep 2012 00:56:15 -0400 Subject: [PATCH 07/13] 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 Signed-off-by: Dmitry Monakhov Signed-off-by: "Theodore Ts'o" (cherry picked from commit 1b65007e9870e0021397b548e8cd6bbc584f9152) --- fs/ext4/inode.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index b84322d..3b03dd6 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4327,9 +4327,14 @@ 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); } -- 1.7.12.rc0.22.gcdd159b