xfs: move inode fork definitions to a new header file

The inode fork definitions are a combination of on-disk format
definition and in-memory tracking and manipulation. They are both
shared with userspace, so move them all into their own file so
sharing is easy to do and track.  This removes all inode fork
related information from xfs_inode.h.

Do the same for the all the C code that currently resides in
xfs_inode.c for the same reason.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_inode_fork.h b/fs/xfs/xfs_inode_fork.h
new file mode 100644
index 0000000..28661a0
--- /dev/null
+++ b/fs/xfs/xfs_inode_fork.h
@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#ifndef	__XFS_INODE_FORK_H__
+#define	__XFS_INODE_FORK_H__
+
+struct xfs_inode_log_item;
+
+/*
+ * The following xfs_ext_irec_t struct introduces a second (top) level
+ * to the in-core extent allocation scheme. These structs are allocated
+ * in a contiguous block, creating an indirection array where each entry
+ * (irec) contains a pointer to a buffer of in-core extent records which
+ * it manages. Each extent buffer is 4k in size, since 4k is the system
+ * page size on Linux i386 and systems with larger page sizes don't seem
+ * to gain much, if anything, by using their native page size as the
+ * extent buffer size. Also, using 4k extent buffers everywhere provides
+ * a consistent interface for CXFS across different platforms.
+ *
+ * There is currently no limit on the number of irec's (extent lists)
+ * allowed, so heavily fragmented files may require an indirection array
+ * which spans multiple system pages of memory. The number of extents
+ * which would require this amount of contiguous memory is very large
+ * and should not cause problems in the foreseeable future. However,
+ * if the memory needed for the contiguous array ever becomes a problem,
+ * it is possible that a third level of indirection may be required.
+ */
+typedef struct xfs_ext_irec {
+	xfs_bmbt_rec_host_t *er_extbuf;	/* block of extent records */
+	xfs_extnum_t	er_extoff;	/* extent offset in file */
+	xfs_extnum_t	er_extcount;	/* number of extents in page/block */
+} xfs_ext_irec_t;
+
+/*
+ * File incore extent information, present for each of data & attr forks.
+ */
+#define	XFS_IEXT_BUFSZ		4096
+#define	XFS_LINEAR_EXTS		(XFS_IEXT_BUFSZ / (uint)sizeof(xfs_bmbt_rec_t))
+#define	XFS_INLINE_EXTS		2
+#define	XFS_INLINE_DATA		32
+typedef struct xfs_ifork {
+	int			if_bytes;	/* bytes in if_u1 */
+	int			if_real_bytes;	/* bytes allocated in if_u1 */
+	struct xfs_btree_block	*if_broot;	/* file's incore btree root */
+	short			if_broot_bytes;	/* bytes allocated for root */
+	unsigned char		if_flags;	/* per-fork flags */
+	union {
+		xfs_bmbt_rec_host_t *if_extents;/* linear map file exts */
+		xfs_ext_irec_t	*if_ext_irec;	/* irec map file exts */
+		char		*if_data;	/* inline file data */
+	} if_u1;
+	union {
+		xfs_bmbt_rec_host_t if_inline_ext[XFS_INLINE_EXTS];
+						/* very small file extents */
+		char		if_inline_data[XFS_INLINE_DATA];
+						/* very small file data */
+		xfs_dev_t	if_rdev;	/* dev number if special */
+		uuid_t		if_uuid;	/* mount point value */
+	} if_u2;
+} xfs_ifork_t;
+
+/*
+ * Per-fork incore inode flags.
+ */
+#define	XFS_IFINLINE	0x01	/* Inline data is read in */
+#define	XFS_IFEXTENTS	0x02	/* All extent pointers are read in */
+#define	XFS_IFBROOT	0x04	/* i_broot points to the bmap b-tree root */
+#define	XFS_IFEXTIREC	0x08	/* Indirection array of extent blocks */
+
+/*
+ * Fork handling.
+ */
+
+#define XFS_IFORK_Q(ip)			((ip)->i_d.di_forkoff != 0)
+#define XFS_IFORK_BOFF(ip)		((int)((ip)->i_d.di_forkoff << 3))
+
+#define XFS_IFORK_PTR(ip,w)		\
+	((w) == XFS_DATA_FORK ? \
+		&(ip)->i_df : \
+		(ip)->i_afp)
+#define XFS_IFORK_DSIZE(ip) \
+	(XFS_IFORK_Q(ip) ? \
+		XFS_IFORK_BOFF(ip) : \
+		XFS_LITINO((ip)->i_mount, (ip)->i_d.di_version))
+#define XFS_IFORK_ASIZE(ip) \
+	(XFS_IFORK_Q(ip) ? \
+		XFS_LITINO((ip)->i_mount, (ip)->i_d.di_version) - \
+			XFS_IFORK_BOFF(ip) : \
+		0)
+#define XFS_IFORK_SIZE(ip,w) \
+	((w) == XFS_DATA_FORK ? \
+		XFS_IFORK_DSIZE(ip) : \
+		XFS_IFORK_ASIZE(ip))
+#define XFS_IFORK_FORMAT(ip,w) \
+	((w) == XFS_DATA_FORK ? \
+		(ip)->i_d.di_format : \
+		(ip)->i_d.di_aformat)
+#define XFS_IFORK_FMT_SET(ip,w,n) \
+	((w) == XFS_DATA_FORK ? \
+		((ip)->i_d.di_format = (n)) : \
+		((ip)->i_d.di_aformat = (n)))
+#define XFS_IFORK_NEXTENTS(ip,w) \
+	((w) == XFS_DATA_FORK ? \
+		(ip)->i_d.di_nextents : \
+		(ip)->i_d.di_anextents)
+#define XFS_IFORK_NEXT_SET(ip,w,n) \
+	((w) == XFS_DATA_FORK ? \
+		((ip)->i_d.di_nextents = (n)) : \
+		((ip)->i_d.di_anextents = (n)))
+#define XFS_IFORK_MAXEXT(ip, w) \
+	(XFS_IFORK_SIZE(ip, w) / sizeof(xfs_bmbt_rec_t))
+
+int		xfs_iformat_fork(struct xfs_inode *, struct xfs_dinode *);
+void		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
+				struct xfs_inode_log_item *, int,
+				struct xfs_buf *);
+void		xfs_idestroy_fork(struct xfs_inode *, int);
+void		xfs_idata_realloc(struct xfs_inode *, int, int);
+void		xfs_iroot_realloc(struct xfs_inode *, int, int);
+int		xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
+int		xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
+				  int);
+
+struct xfs_bmbt_rec_host *
+		xfs_iext_get_ext(struct xfs_ifork *, xfs_extnum_t);
+void		xfs_iext_insert(struct xfs_inode *, xfs_extnum_t, xfs_extnum_t,
+				struct xfs_bmbt_irec *, int);
+void		xfs_iext_add(struct xfs_ifork *, xfs_extnum_t, int);
+void		xfs_iext_add_indirect_multi(struct xfs_ifork *, int,
+					    xfs_extnum_t, int);
+void		xfs_iext_remove(struct xfs_inode *, xfs_extnum_t, int, int);
+void		xfs_iext_remove_inline(struct xfs_ifork *, xfs_extnum_t, int);
+void		xfs_iext_remove_direct(struct xfs_ifork *, xfs_extnum_t, int);
+void		xfs_iext_remove_indirect(struct xfs_ifork *, xfs_extnum_t, int);
+void		xfs_iext_realloc_direct(struct xfs_ifork *, int);
+void		xfs_iext_direct_to_inline(struct xfs_ifork *, xfs_extnum_t);
+void		xfs_iext_inline_to_direct(struct xfs_ifork *, int);
+void		xfs_iext_destroy(struct xfs_ifork *);
+struct xfs_bmbt_rec_host *
+		xfs_iext_bno_to_ext(struct xfs_ifork *, xfs_fileoff_t, int *);
+struct xfs_ext_irec *
+		xfs_iext_bno_to_irec(struct xfs_ifork *, xfs_fileoff_t, int *);
+struct xfs_ext_irec *
+		xfs_iext_idx_to_irec(struct xfs_ifork *, xfs_extnum_t *, int *,
+				     int);
+void		xfs_iext_irec_init(struct xfs_ifork *);
+struct xfs_ext_irec *
+		xfs_iext_irec_new(struct xfs_ifork *, int);
+void		xfs_iext_irec_remove(struct xfs_ifork *, int);
+void		xfs_iext_irec_compact(struct xfs_ifork *);
+void		xfs_iext_irec_compact_pages(struct xfs_ifork *);
+void		xfs_iext_irec_compact_full(struct xfs_ifork *);
+void		xfs_iext_irec_update_extoffs(struct xfs_ifork *, int, int);
+
+extern struct kmem_zone	*xfs_ifork_zone;
+
+#endif	/* __XFS_INODE_FORK_H__ */