xfs: fully support v5 format filesystems

We have had this code in the kernel for over a year now and have
shaken all the known issues out of the code over the past few
releases. It's now time to remove the experimental warnings during
mount and fully support the new filesystem format in production
systems.

Remove the experimental warning, and add a version number to the
initial "mounting filesystem" message to tell use what type of
filesystem is being mounted. Also, remove the temporary inode
cluster size output at mount time now we know that this code works
fine.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
xfs: initialize default acls for ->tmpfile()

The current tmpfile handler does not initialize default ACLs. Doing so
within xfs_vn_tmpfile() makes it roughly equivalent to xfs_vn_mknod(),
which is already used as a common create handler.

xfs_vn_mknod() does not currently have a mechanism to determine whether
to link the file into the namespace. Therefore, further abstract
xfs_vn_mknod() into a new xfs_generic_create() handler with a tmpfile
parameter. This new handler calls xfs_create_tmpfile() and d_tmpfile()
on the dentry when called via ->tmpfile().

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
xfs: remote attribute overwrite causes transaction overrun

Commit e461fcb ("xfs: remote attribute lookups require the value
length") passes the remote attribute length in the xfs_da_args
structure on lookup so that CRC calculations and validity checking
can be performed correctly by related code. This, unfortunately has
the side effect of changing the args->valuelen parameter in cases
where it shouldn't.

That is, when we replace a remote attribute, the incoming
replacement stores the value and length in args->value and
args->valuelen, but then the lookup which finds the existing remote
attribute overwrites args->valuelen with the length of the remote
attribute being replaced. Hence when we go to create the new
attribute, we create it of the size of the existing remote
attribute, not the size it is supposed to be. When the new attribute
is much smaller than the old attribute, this results in a
transaction overrun and an ASSERT() failure on a debug kernel:

XFS: Assertion failed: tp->t_blk_res_used <= tp->t_blk_res, file: fs/xfs/xfs_trans.c, line: 331

Fix this by keeping the remote attribute value length separate to
the attribute value length in the xfs_da_args structure. The enables
us to pass the length of the remote attribute to be removed without
overwriting the new attribute's length.

Also, ensure that when we save remote block contexts for a later
rename we zero the original state variables so that we don't confuse
the state of the attribute to be removes with the state of the new
attribute that we just added. [Spotted by Brain Foster.]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Merge tag 'xfs-for-linus-3.15-rc5' of git://oss.sgi.com/xfs/xfs

Pull xfs fixes from Dave Chinner:
 "The main fix is adding support for default ACLs on O_TMPFILE opened
  inodes to bring XFS into line with other filesystems.  Metadata CRCs
  are now also considered well enough tested to be fully supported, so
  we're removing the shouty warnings issued at mount time for
  filesystems with that format.  And there's transaction block
  reservation overrun fix.

  Summary:
   - fix a remote attribute size calculation bug that leads to a
     transaction overrun
   - add default ACLs to O_TMPFILE files
   - Remove the EXPERIMENTAL tag from filesystems with metadata CRC
     support"

* tag 'xfs-for-linus-3.15-rc5' of git://oss.sgi.com/xfs/xfs:
  xfs: remote attribute overwrite causes transaction overrun
  xfs: initialize default acls for ->tmpfile()
  xfs: fully support v5 format filesystems