Re: [PATCH 08/10] ext4: endless truncate due to nonlocked dio readers V2
From: Jan Kara <jack@suse.cz>
Date: 2012-09-26 14:05:40
On Mon 24-09-12 15:44:18, Dmitry Monakhov wrote:
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.
Umm, actually this is a problem with any inode_dio_wait() call in ext4, isn't it? So I'd just create ext4_inode_dio_wait() doing ext4_inode_block_unlocked_dio(inode); inode_dio_wait(inode); ext4_inode_resume_unlocked_dio(inode); and use it instead of inode_dio_wait(). Honza
quoted hunk ↗ jump to hunk
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 */
^^ Temporarily
+ 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-- Jan Kara [off-list ref] SUSE Labs, CR