From: Andrew Morton Date: Wed, 17 Oct 2007 06:30:36 +0000 (-0700) Subject: writeback: fix time ordering of the per superblock dirty inode lists 5 X-Git-Tag: v2.6.24-rc1~572 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=c6945e77e477103057b4a639b4b01596f5257861;p=linux-2.6-omap-h63xx.git writeback: fix time ordering of the per superblock dirty inode lists 5 When the writeback function is operating in writeback-for-flushing mode (as opposed to writeback-for-integrity) and it encounters an I_LOCKed inode, it will skip writing that inode. This is done for throughput and latency: move on to another inode rather than blocking for this one. Writeback skips this inode by moving it off s_io and onto s_dirty, so that writeback can proceed with the other inodes on s_io. However that inode movement can corrupt s_dirty's reverse-time-orderedness. Fix that by using the new redirty_tail(), which will update the refiled inode's dirtied_when field. Note: the behaviour in here is a bit rude: if kupdate happens to come across a locked inode then it will defer writeback of that inode for another 30 seconds. We'll address that in the next patch. Cc: Mike Waychison Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index a3d7a829137..1b43cc9d9eb 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -308,7 +308,7 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc) struct address_space *mapping = inode->i_mapping; int ret; - list_move(&inode->i_list, &inode->i_sb->s_dirty); + redirty_tail(inode); /* * Even if we don't actually write the inode itself here,