On Mon, Sep 25, 2023 at 02:59:16PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong <djwong@xxxxxxxxxx> > > XFS and tools (mkfs, copy, repair) don't generally rely on the block > device page cache, preferring instead to use directio. For whatever > reason, the debugger was never made to do this, but let's do that now. > > This should eliminate the weird fstests failures resulting from > udev/blkid pinning a cache page while the unmounting filesystem writes > to the superblock such that xfs_db finds the stale pagecache instead of > the post-unmount superblock. After some debugging I found out that this breaks a bunch of tests (at least xfs/002 xfs/070 xfs/424 in the quick group) on 4k device because xfs_db tries some unaligned reads. For xfs/002 that is the libxfs_buf_read in __set_cur, when setting the type to data, but I haven't looked at the other test in detail. Should I look into finding all these assumptions in xfs_db, or just make the direct I/O enablement conditional n a 612 byte sector size?
