xfs: consolidate extent swap code

So we don't need xfs_dfrag.h in userspace anymore, move the extent
swap ioctl structure definition to xfs_fs.h where most of the other
ioctl structure definitions are.

Now that we don't need separate files for extent swapping, separate
the basic file descriptor checking code to xfs_ioctl.c, and the code
that does the extent swap operation to xfs_bmap_util.c.  This
cleanly separates the user interface code from the physical
mechanism used to do the extent swap.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/Makefile

@@ -32,7 +32,6 @@ xfs-y				+= xfs_aops.o \
 				   xfs_bit.o \
 				   xfs_bmap_util.o \
 				   xfs_buf.o \
-				   xfs_dfrag.o \
 				   xfs_dir2_readdir.o \
 				   xfs_discard.o \
 				   xfs_error.o \

fs/xfs/xfs_bmap_util.h

@@ -102,6 +102,9 @@ bool	xfs_can_free_eofblocks(struct xfs_inode *ip, bool force);
 int	xfs_free_eofblocks(struct xfs_mount *mp, struct xfs_inode *ip,
 			   bool need_iolock);
 
+int	xfs_swap_extents(struct xfs_inode *ip, struct xfs_inode *tip,
+			 struct xfs_swapext *sx);
+
 xfs_daddr_t xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb);
 
 #endif	/* __XFS_BMAP_UTIL_H__ */

fs/xfs/xfs_dfrag.h

-/*
- * Copyright (c) 2000,2005 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_DFRAG_H__
-#define	__XFS_DFRAG_H__
-
-/*
- * Structure passed to xfs_swapext
- */
-
-typedef struct xfs_swapext
-{
-	__int64_t	sx_version;	/* version */
-	__int64_t	sx_fdtarget;	/* fd of target file */
-	__int64_t	sx_fdtmp;	/* fd of tmp file */
-	xfs_off_t	sx_offset;	/* offset into file */
-	xfs_off_t	sx_length;	/* leng from offset */
-	char		sx_pad[16];	/* pad space, unused */
-	xfs_bstat_t	sx_stat;	/* stat of target b4 copy */
-} xfs_swapext_t;
-
-/*
- * Version flag
- */
-#define XFS_SX_VERSION		0
-
-#ifdef __KERNEL__
-/*
- * Prototypes for visible xfs_dfrag.c routines.
- */
-
-/*
- * Syscall interface for xfs_swapext
- */
-int	xfs_swapext(struct xfs_swapext *sx);
-
-#endif	/* __KERNEL__ */
-
-#endif	/* __XFS_DFRAG_H__ */

fs/xfs/xfs_fs.h

@@ -460,6 +460,21 @@ typedef struct xfs_handle {
 				 - (char *) &(handle))			  \
 				 + (handle).ha_fid.fid_len)
 
+/*
+ * Structure passed to XFS_IOC_SWAPEXT
+ */
+typedef struct xfs_swapext
+{
+	__int64_t	sx_version;	/* version */
+#define XFS_SX_VERSION		0
+	__int64_t	sx_fdtarget;	/* fd of target file */
+	__int64_t	sx_fdtmp;	/* fd of tmp file */
+	xfs_off_t	sx_offset;	/* offset into file */
+	xfs_off_t	sx_length;	/* leng from offset */
+	char		sx_pad[16];	/* pad space, unused */
+	xfs_bstat_t	sx_stat;	/* stat of target b4 copy */
+} xfs_swapext_t;
+
 /*
  * Flags for going down operation
  */

fs/xfs/xfs_ioctl.c

@@ -35,7 +35,6 @@
 #include "xfs_bmap.h"
 #include "xfs_bmap_util.h"
 #include "xfs_buf_item.h"
-#include "xfs_dfrag.h"
 #include "xfs_fsops.h"
 #include "xfs_discard.h"
 #include "xfs_quota.h"
@@ -1363,6 +1362,75 @@ xfs_ioc_getbmapx(
 	return 0;
 }
 
+int
+xfs_ioc_swapext(
+	xfs_swapext_t	*sxp)
+{
+	xfs_inode_t     *ip, *tip;
+	struct fd	f, tmp;
+	int		error = 0;
+
+	/* Pull information for the target fd */
+	f = fdget((int)sxp->sx_fdtarget);
+	if (!f.file) {
+		error = XFS_ERROR(EINVAL);
+		goto out;
+	}
+
+	if (!(f.file->f_mode & FMODE_WRITE) ||
+	    !(f.file->f_mode & FMODE_READ) ||
+	    (f.file->f_flags & O_APPEND)) {
+		error = XFS_ERROR(EBADF);
+		goto out_put_file;
+	}
+
+	tmp = fdget((int)sxp->sx_fdtmp);
+	if (!tmp.file) {
+		error = XFS_ERROR(EINVAL);
+		goto out_put_file;
+	}
+
+	if (!(tmp.file->f_mode & FMODE_WRITE) ||
+	    !(tmp.file->f_mode & FMODE_READ) ||
+	    (tmp.file->f_flags & O_APPEND)) {
+		error = XFS_ERROR(EBADF);
+		goto out_put_tmp_file;
+	}
+
+	if (IS_SWAPFILE(file_inode(f.file)) ||
+	    IS_SWAPFILE(file_inode(tmp.file))) {
+		error = XFS_ERROR(EINVAL);
+		goto out_put_tmp_file;
+	}
+
+	ip = XFS_I(file_inode(f.file));
+	tip = XFS_I(file_inode(tmp.file));
+
+	if (ip->i_mount != tip->i_mount) {
+		error = XFS_ERROR(EINVAL);
+		goto out_put_tmp_file;
+	}
+
+	if (ip->i_ino == tip->i_ino) {
+		error = XFS_ERROR(EINVAL);
+		goto out_put_tmp_file;
+	}
+
+	if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+		error = XFS_ERROR(EIO);
+		goto out_put_tmp_file;
+	}
+
+	error = xfs_swap_extents(ip, tip, sxp);
+
+ out_put_tmp_file:
+	fdput(tmp);
+ out_put_file:
+	fdput(f);
+ out:
+	return error;
+}
+
 /*
  * Note: some of the ioctl's return positive numbers as a
  * byte count indicating success, such as readlink_by_handle.
@@ -1507,7 +1575,7 @@ xfs_file_ioctl(
 		error = mnt_want_write_file(filp);
 		if (error)
 			return error;
-		error = xfs_swapext(&sxp);
+		error = xfs_ioc_swapext(&sxp);
 		mnt_drop_write_file(filp);
 		return -error;
 	}

fs/xfs/xfs_ioctl.h

@@ -27,6 +27,10 @@ xfs_ioc_space(
 	unsigned int		cmd,
 	xfs_flock64_t		*bf);
 
+int
+xfs_ioc_swapext(
+	xfs_swapext_t	*sxp);
+
 extern int
 xfs_find_handle(
 	unsigned int		cmd,

fs/xfs/xfs_ioctl32.c

@@ -33,7 +33,6 @@
 #include "xfs_inode.h"
 #include "xfs_itable.h"
 #include "xfs_error.h"
-#include "xfs_dfrag.h"
 #include "xfs_fsops.h"
 #include "xfs_alloc.h"
 #include "xfs_rtalloc.h"
@@ -643,7 +642,7 @@ xfs_file_compat_ioctl(
 		error = mnt_want_write_file(filp);
 		if (error)
 			return error;
-		error = xfs_swapext(&sxp);
+		error = xfs_ioc_swapext(&sxp);
 		mnt_drop_write_file(filp);
 		return -error;
 	}