Commit 670e4def authored Oct 16, 2007 by Andrew Morton Committed by Linus Torvalds Oct 17, 2007

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>

parent 65cb9b47

fs/fs-writeback.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -410,14 +410,14 @@ sync_sb_inodes(struct super_block sb, struct writeback_control wbc)
		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 */
		}