[PATCH 08/25] xfs: introduce xfs_bmapi_delay()

[Christoph Hellwig]

> > +	xfs_extnum_t		lastx;	/* last useful extent number */
> > +	int			eof;	/* we've hit the end of extents */
> > +	int			n = 0;	/* current extent index */
> > +	int			error = 0;
> > +
> > +	ASSERT(*nmap >= 1);
> > +	ASSERT(*nmap <= XFS_BMAP_MAX_NMAP);
> > +	ASSERT(!(flags & ~XFS_BMAPI_ENTIRE));
> > +
> 
> Rearrange the following test to use the pattern (assigning error)
> used in xfs_bmapi_read().

Hmm - given that error is used as a boolean there I don't actually like
that pattern very much as error is generally used to hold an errno
value.

> 
> > +	if (unlikely(XFS_TEST_ERROR(
> > +	    (XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_EXTENTS &&
> > +	     XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_BTREE),
> 
> Are you certain that XFS_DINODE_FMT_LOCAL is not possible here?
> I tried to trace it back but I'm still not sure.  The transaction
> pointer passed is null, so it would have tripped an assertion
> in the previous code.  (A simple explanation would reassure me.)

We can't hit it because we do not support the local format for regular
files at all, and we do not support delayed allocations for anything
but regular files.