writeback: fix time ordering of the per superblock dirty inode lists 7
This one fixes four bugs.
There are a few situation in there where writeback decides it is going to skip
over a blockdev inode on the kernel-internal blockdev superblock. It
presently does this by moving the blockdev inode onto the tail of the blockdev
superblock's s_dirty. But
a) this screws up s_dirty's reverse-time-orderedness and
b) refiling the blockdev for writeback in another 30 second is rude. We
should try again sooner than that.
Fix all this up by using redirty_head(): move the blockdev inode onto the head
of the blockdev superblock's s_dirty list for prompt writeback.
Cc: Mike Waychison <mikew@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 30d9383..39fadfa 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -410,14 +410,14 @@
wbc->encountered_congestion = 1;
if (!sb_is_blkdev_sb(sb))
break; /* Skip a congested fs */
- list_move(&inode->i_list, &sb->s_dirty);
+ redirty_head(inode);
continue; /* Skip a congested blockdev */
}
if (wbc->bdi && bdi != wbc->bdi) {
if (!sb_is_blkdev_sb(sb))
break; /* fs has the wrong queue */
- list_move(&inode->i_list, &sb->s_dirty);
+ redirty_head(inode);
continue; /* blockdev has wrong queue */
}