Dave Chinner <david <at> fromorbit.com> writes:
> This series closes a recently discovered problem in XFS filehandle
> On systems where inodes are dynamically deleted, XFS does not adequately
> the inode numbers in the filehandles, which results in reading stale inodes
> from disk and potentially returning them as valid files. Because these
> inodes were never zeroed out when the chunk was deallocated, some inodes in
> chunk can still appear to have to data extents attached to them. This can
> to stale data exposure, exposure of active data and potentially overwriting
> active data if the stale extents referenced in the unlinked inodes have been
> Both NFS filehandles and local filehandles provided through libhandle have
> same problem. libhandle requires root permissions to use the interface, so it
> is not exposing information that you can't get more easily with other means
> (e.g. xfs_db or reading directly form the block device), so there isn't
> an issue here.
> For NFS, we may incorrectly accept stale file handles for unlinked inodes
> a server reboot if the unlinked inodes have not been overwritten leading to
> above issues being triggered if multiple NFS clients are accessing the some
> Christoph's make-bulkstat-coherent patch is the basis for this series as
> bulkstat can also expose unlinked inodes and information about them back to
> userspace because it makes the same assumptions about inode lookups as the
> handle interfaces.
> As a result, the first two patches of the series make up the real bug fix.
> last two patches make it clear we are looking up untrusted inode numbers and
> remove a shortcut that these interfaces used that we do not want used any
> more. Hence for backports to other kernels, only the first two patches are
> More information and the test program that demonstrates the issue via the
> open_by_handle interface can be found here:
> xfs mailing list
> xfs <at> oss.sgi.com
I meet with a problem when using 64bit XFS and NFS,
When I access a directory from the NFS client,I get Stale NFS file Handle
error.But it is ok when accessing on the server without NFS.
And I have checked that the inode num in the NFS file handle is the same as
inode num on the server, Using ls -il.
I found that XFS_IGET_UNTRUSTED in xfs_imap() filtered the function
xfs_imap_lookup(),It fails in xfs_imap_lookup() when access from NFS
client.local access does not go into xfs_imap_lookup().
My kernel is Linux22.214.171.124 from kernel.org. please help me to find out this