From: Andrew Morton Date: Wed, 17 Oct 2007 06:30:34 +0000 (-0700) Subject: writeback: fix time ordering of the per superblock dirty inode lists 3 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f57b9b7b4f68e1723ca99381dc10c8bc07d6df14;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git writeback: fix time ordering of the per superblock dirty inode lists 3 While writeback is working against a dirty inode it does a check after trying to write some of the inode's pages: "did the lower layers skip some of the inode's dirty pages because they were locked (or under writeback, or whatever)" If this turns out to be true, we must move the inode back onto s_dirty and redirty it. The reason for doing this is that fsync() and friends only check the s_dirty list, and those functions want to know about those pages which were locked, so they can be waited upon and, if necessary, rewritten. Problem is, that redirtying was putting the inode onto the tail of s_dirty without updating its timestamp. This causes a violation of s_dirty ordering. Fix this by updating inode->dirtied_when when moving the inode onto s_dirty. But the code is still a bit buggy? If the inode was _already_ dirty then we don't need to move it at all. Oh well, hopefully it doesn't matter too much, as that was a redirtying, which was very recent anwyay. 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 f8618e0bb62b..66889b06d00f 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -413,7 +413,7 @@ sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc) * writeback is not making progress due to locked * buffers. Skip this inode for now. */ - list_move(&inode->i_list, &sb->s_dirty); + redirty_tail(inode); } spin_unlock(&inode_lock); iput(inode);