Re: ZFS checksum errors on USB attach (Was: ZFS data error without reasons)

On Wednesday 08 April 2009 11:31:08 am Norikatsu Shigemura wrote:
> Hi jhb!
> 
> 	I got ZFS checksum error issue, too.  So I found a way of fixing
> 	this issue.  Please back out following change.
> 
> sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.c
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> revision 1.5
> date: 2009/03/18 16:19:44;  author: jhb;  state: Exp;  lines: +2 -0
> SVN rev 189967 on 2009-03-18 16:19:44Z by jhb
> 
> The zfs_get_xattrdir() function is used to find the extended attribute
> directory for a znode.  When the directory already exists, it returns a
> referenced but unlocked vnode.  When a directory does not yet exist, it
> calls zfs_make_xattrdir() to create a new one.  zfs_make_xattrdir() returns
> the vnode both referenced and and locked and zfs_get_xattrdir() was leaking
> this vnode lock to its callers.  Fix this by dropping the vnode lock if
> zfs_make_xattrdir() successfully creates a new extended attribute
> directory.
> 
> Reviewed by:    pjd
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> 
> 	[Validation]
> 	1. I got ZFS checksum error issue
> 	2. Backup
> 	3. Restructure ZPool
> 	4. Restore (But ZFS checksum error)
> 	5. Restructure ZPool with kern.smp.disabled=1
> 	   (Almost good, but...)
> 	6. Restore
> 	7. Backout zfs_dir#1.5
> 	8. Good works for me
> 
> 	I tested many backup&restore:-).

I have no idea how this would break what you are seeing.  The 
zfs_get_xattrdir() function is only called from zfs_lookup() when 
LOOKUP_XATTR is specified, and that only happens from the extended attribute 
VOP routines.  Are you using extended attributes at all?  Also, have you 
tried running with INVARIANTS and DEBUG_VFS_LOCKS to catch missing locks?

-- 
John Baldwin