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: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen 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.c

@@ -1693,3 +1693,346 @@ xfs_change_file_space(
 		xfs_trans_set_sync(tp);
 	return xfs_trans_commit(tp, 0);
 }
+
+/*
+ * We need to check that the format of the data fork in the temporary inode is
+ * valid for the target inode before doing the swap. This is not a problem with
+ * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
+ * data fork depending on the space the attribute fork is taking so we can get
+ * invalid formats on the target inode.
+ *
+ * E.g. target has space for 7 extents in extent format, temp inode only has
+ * space for 6.  If we defragment down to 7 extents, then the tmp format is a
+ * btree, but when swapped it needs to be in extent format. Hence we can't just
+ * blindly swap data forks on attr2 filesystems.
+ *
+ * Note that we check the swap in both directions so that we don't end up with
+ * a corrupt temporary inode, either.
+ *
+ * Note that fixing the way xfs_fsr sets up the attribute fork in the source
+ * inode will prevent this situation from occurring, so all we do here is
+ * reject and log the attempt. basically we are putting the responsibility on
+ * userspace to get this right.
+ */
+static int
+xfs_swap_extents_check_format(
+	xfs_inode_t	*ip,	/* target inode */
+	xfs_inode_t	*tip)	/* tmp inode */
+{
+
+	/* Should never get a local format */
+	if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
+	    tip->i_d.di_format == XFS_DINODE_FMT_LOCAL)
+		return EINVAL;
+
+	/*
+	 * if the target inode has less extents that then temporary inode then
+	 * why did userspace call us?
+	 */
+	if (ip->i_d.di_nextents < tip->i_d.di_nextents)
+		return EINVAL;
+
+	/*
+	 * if the target inode is in extent form and the temp inode is in btree
+	 * form then we will end up with the target inode in the wrong format
+	 * as we already know there are less extents in the temp inode.
+	 */
+	if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
+	    tip->i_d.di_format == XFS_DINODE_FMT_BTREE)
+		return EINVAL;
+
+	/* Check temp in extent form to max in target */
+	if (tip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
+	    XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) >
+			XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
+		return EINVAL;
+
+	/* Check target in extent form to max in temp */
+	if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
+	    XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) >
+			XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
+		return EINVAL;
+
+	/*
+	 * If we are in a btree format, check that the temp root block will fit
+	 * in the target and that it has enough extents to be in btree format
+	 * in the target.
+	 *
+	 * Note that we have to be careful to allow btree->extent conversions
+	 * (a common defrag case) which will occur when the temp inode is in
+	 * extent format...
+	 */
+	if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
+		if (XFS_IFORK_BOFF(ip) &&
+		    XFS_BMAP_BMDR_SPACE(tip->i_df.if_broot) > XFS_IFORK_BOFF(ip))
+			return EINVAL;
+		if (XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <=
+		    XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
+			return EINVAL;
+	}
+
+	/* Reciprocal target->temp btree format checks */
+	if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
+		if (XFS_IFORK_BOFF(tip) &&
+		    XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > XFS_IFORK_BOFF(tip))
+			return EINVAL;
+		if (XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <=
+		    XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
+			return EINVAL;
+	}
+
+	return 0;
+}
+
+int
+xfs_swap_extents(
+	xfs_inode_t	*ip,	/* target inode */
+	xfs_inode_t	*tip,	/* tmp inode */
+	xfs_swapext_t	*sxp)
+{
+	xfs_mount_t	*mp = ip->i_mount;
+	xfs_trans_t	*tp;
+	xfs_bstat_t	*sbp = &sxp->sx_stat;
+	xfs_ifork_t	*tempifp, *ifp, *tifp;
+	int		src_log_flags, target_log_flags;
+	int		error = 0;
+	int		aforkblks = 0;
+	int		taforkblks = 0;
+	__uint64_t	tmp;
+
+	/*
+	 * We have no way of updating owner information in the BMBT blocks for
+	 * each inode on CRC enabled filesystems, so to avoid corrupting the
+	 * this metadata we simply don't allow extent swaps to occur.
+	 */
+	if (xfs_sb_version_hascrc(&mp->m_sb))
+		return XFS_ERROR(EINVAL);
+
+	tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
+	if (!tempifp) {
+		error = XFS_ERROR(ENOMEM);
+		goto out;
+	}
+
+	/*
+	 * we have to do two separate lock calls here to keep lockdep
+	 * happy. If we try to get all the locks in one call, lock will
+	 * report false positives when we drop the ILOCK and regain them
+	 * below.
+	 */
+	xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
+	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
+
+	/* Verify that both files have the same format */
+	if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
+		error = XFS_ERROR(EINVAL);
+		goto out_unlock;
+	}
+
+	/* Verify both files are either real-time or non-realtime */
+	if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
+		error = XFS_ERROR(EINVAL);
+		goto out_unlock;
+	}
+
+	error = -filemap_write_and_wait(VFS_I(tip)->i_mapping);
+	if (error)
+		goto out_unlock;
+	truncate_pagecache_range(VFS_I(tip), 0, -1);
+
+	/* Verify O_DIRECT for ftmp */
+	if (VN_CACHED(VFS_I(tip)) != 0) {
+		error = XFS_ERROR(EINVAL);
+		goto out_unlock;
+	}
+
+	/* Verify all data are being swapped */
+	if (sxp->sx_offset != 0 ||
+	    sxp->sx_length != ip->i_d.di_size ||
+	    sxp->sx_length != tip->i_d.di_size) {
+		error = XFS_ERROR(EFAULT);
+		goto out_unlock;
+	}
+
+	trace_xfs_swap_extent_before(ip, 0);
+	trace_xfs_swap_extent_before(tip, 1);
+
+	/* check inode formats now that data is flushed */
+	error = xfs_swap_extents_check_format(ip, tip);
+	if (error) {
+		xfs_notice(mp,
+		    "%s: inode 0x%llx format is incompatible for exchanging.",
+				__func__, ip->i_ino);
+		goto out_unlock;
+	}
+
+	/*
+	 * Compare the current change & modify times with that
+	 * passed in.  If they differ, we abort this swap.
+	 * This is the mechanism used to ensure the calling
+	 * process that the file was not changed out from
+	 * under it.
+	 */
+	if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||
+	    (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||
+	    (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||
+	    (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {
+		error = XFS_ERROR(EBUSY);
+		goto out_unlock;
+	}
+
+	/* We need to fail if the file is memory mapped.  Once we have tossed
+	 * all existing pages, the page fault will have no option
+	 * but to go to the filesystem for pages. By making the page fault call
+	 * vop_read (or write in the case of autogrow) they block on the iolock
+	 * until we have switched the extents.
+	 */
+	if (VN_MAPPED(VFS_I(ip))) {
+		error = XFS_ERROR(EBUSY);
+		goto out_unlock;
+	}
+
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	xfs_iunlock(tip, XFS_ILOCK_EXCL);
+
+	/*
+	 * There is a race condition here since we gave up the
+	 * ilock.  However, the data fork will not change since
+	 * we have the iolock (locked for truncation too) so we
+	 * are safe.  We don't really care if non-io related
+	 * fields change.
+	 */
+	truncate_pagecache_range(VFS_I(ip), 0, -1);
+
+	tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
+	if ((error = xfs_trans_reserve(tp, 0,
+				     XFS_ICHANGE_LOG_RES(mp), 0,
+				     0, 0))) {
+		xfs_iunlock(ip,  XFS_IOLOCK_EXCL);
+		xfs_iunlock(tip, XFS_IOLOCK_EXCL);
+		xfs_trans_cancel(tp, 0);
+		goto out;
+	}
+	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
+
+	/*
+	 * Count the number of extended attribute blocks
+	 */
+	if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
+	     (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
+		error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
+		if (error)
+			goto out_trans_cancel;
+	}
+	if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
+	     (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
+		error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
+			&taforkblks);
+		if (error)
+			goto out_trans_cancel;
+	}
+
+	/*
+	 * Swap the data forks of the inodes
+	 */
+	ifp = &ip->i_df;
+	tifp = &tip->i_df;
+	*tempifp = *ifp;	/* struct copy */
+	*ifp = *tifp;		/* struct copy */
+	*tifp = *tempifp;	/* struct copy */
+
+	/*
+	 * Fix the on-disk inode values
+	 */
+	tmp = (__uint64_t)ip->i_d.di_nblocks;
+	ip->i_d.di_nblocks = tip->i_d.di_nblocks - taforkblks + aforkblks;
+	tip->i_d.di_nblocks = tmp + taforkblks - aforkblks;
+
+	tmp = (__uint64_t) ip->i_d.di_nextents;
+	ip->i_d.di_nextents = tip->i_d.di_nextents;
+	tip->i_d.di_nextents = tmp;
+
+	tmp = (__uint64_t) ip->i_d.di_format;
+	ip->i_d.di_format = tip->i_d.di_format;
+	tip->i_d.di_format = tmp;
+
+	/*
+	 * The extents in the source inode could still contain speculative
+	 * preallocation beyond EOF (e.g. the file is open but not modified
+	 * while defrag is in progress). In that case, we need to copy over the
+	 * number of delalloc blocks the data fork in the source inode is
+	 * tracking beyond EOF so that when the fork is truncated away when the
+	 * temporary inode is unlinked we don't underrun the i_delayed_blks
+	 * counter on that inode.
+	 */
+	ASSERT(tip->i_delayed_blks == 0);
+	tip->i_delayed_blks = ip->i_delayed_blks;
+	ip->i_delayed_blks = 0;
+
+	src_log_flags = XFS_ILOG_CORE;
+	switch (ip->i_d.di_format) {
+	case XFS_DINODE_FMT_EXTENTS:
+		/* If the extents fit in the inode, fix the
+		 * pointer.  Otherwise it's already NULL or
+		 * pointing to the extent.
+		 */
+		if (ip->i_d.di_nextents <= XFS_INLINE_EXTS) {
+			ifp->if_u1.if_extents =
+				ifp->if_u2.if_inline_ext;
+		}
+		src_log_flags |= XFS_ILOG_DEXT;
+		break;
+	case XFS_DINODE_FMT_BTREE:
+		src_log_flags |= XFS_ILOG_DBROOT;
+		break;
+	}
+
+	target_log_flags = XFS_ILOG_CORE;
+	switch (tip->i_d.di_format) {
+	case XFS_DINODE_FMT_EXTENTS:
+		/* If the extents fit in the inode, fix the
+		 * pointer.  Otherwise it's already NULL or
+		 * pointing to the extent.
+		 */
+		if (tip->i_d.di_nextents <= XFS_INLINE_EXTS) {
+			tifp->if_u1.if_extents =
+				tifp->if_u2.if_inline_ext;
+		}
+		target_log_flags |= XFS_ILOG_DEXT;
+		break;
+	case XFS_DINODE_FMT_BTREE:
+		target_log_flags |= XFS_ILOG_DBROOT;
+		break;
+	}
+
+
+	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+	xfs_trans_ijoin(tp, tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+
+	xfs_trans_log_inode(tp, ip,  src_log_flags);
+	xfs_trans_log_inode(tp, tip, target_log_flags);
+
+	/*
+	 * If this is a synchronous mount, make sure that the
+	 * transaction goes to disk before returning to the user.
+	 */
+	if (mp->m_flags & XFS_MOUNT_WSYNC)
+		xfs_trans_set_sync(tp);
+
+	error = xfs_trans_commit(tp, 0);
+
+	trace_xfs_swap_extent_after(ip, 0);
+	trace_xfs_swap_extent_after(tip, 1);
+out:
+	kmem_free(tempifp);
+	return error;
+
+out_unlock:
+	xfs_iunlock(ip,  XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+	xfs_iunlock(tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+	goto out;
+
+out_trans_cancel:
+	xfs_trans_cancel(tp, 0);
+	goto out_unlock;
+}

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.c

-/*
- * Copyright (c) 2000-2006 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
- */
-#include "xfs.h"
-#include "xfs_fs.h"
-#include "xfs_types.h"
-#include "xfs_log.h"
-#include "xfs_trans.h"
-#include "xfs_sb.h"
-#include "xfs_ag.h"
-#include "xfs_mount.h"
-#include "xfs_bmap_btree.h"
-#include "xfs_alloc_btree.h"
-#include "xfs_ialloc_btree.h"
-#include "xfs_btree.h"
-#include "xfs_dinode.h"
-#include "xfs_inode.h"
-#include "xfs_inode_item.h"
-#include "xfs_bmap.h"
-#include "xfs_bmap_util.h"
-#include "xfs_itable.h"
-#include "xfs_dfrag.h"
-#include "xfs_error.h"
-#include "xfs_trace.h"
-
-
-static int xfs_swap_extents(
-	xfs_inode_t	*ip,	/* target inode */
-	xfs_inode_t	*tip,	/* tmp inode */
-	xfs_swapext_t	*sxp);
-
-/*
- * ioctl interface for swapext
- */
-int
-xfs_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;
-}
-
-/*
- * We need to check that the format of the data fork in the temporary inode is
- * valid for the target inode before doing the swap. This is not a problem with
- * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
- * data fork depending on the space the attribute fork is taking so we can get
- * invalid formats on the target inode.
- *
- * E.g. target has space for 7 extents in extent format, temp inode only has
- * space for 6.  If we defragment down to 7 extents, then the tmp format is a
- * btree, but when swapped it needs to be in extent format. Hence we can't just
- * blindly swap data forks on attr2 filesystems.
- *
- * Note that we check the swap in both directions so that we don't end up with
- * a corrupt temporary inode, either.
- *
- * Note that fixing the way xfs_fsr sets up the attribute fork in the source
- * inode will prevent this situation from occurring, so all we do here is
- * reject and log the attempt. basically we are putting the responsibility on
- * userspace to get this right.
- */
-static int
-xfs_swap_extents_check_format(
-	xfs_inode_t	*ip,	/* target inode */
-	xfs_inode_t	*tip)	/* tmp inode */
-{
-
-	/* Should never get a local format */
-	if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
-	    tip->i_d.di_format == XFS_DINODE_FMT_LOCAL)
-		return EINVAL;
-
-	/*
-	 * if the target inode has less extents that then temporary inode then
-	 * why did userspace call us?
-	 */
-	if (ip->i_d.di_nextents < tip->i_d.di_nextents)
-		return EINVAL;
-
-	/*
-	 * if the target inode is in extent form and the temp inode is in btree
-	 * form then we will end up with the target inode in the wrong format
-	 * as we already know there are less extents in the temp inode.
-	 */
-	if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
-	    tip->i_d.di_format == XFS_DINODE_FMT_BTREE)
-		return EINVAL;
-
-	/* Check temp in extent form to max in target */
-	if (tip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
-	    XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) >
-			XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
-		return EINVAL;
-
-	/* Check target in extent form to max in temp */
-	if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
-	    XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) >
-			XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
-		return EINVAL;
-
-	/*
-	 * If we are in a btree format, check that the temp root block will fit
-	 * in the target and that it has enough extents to be in btree format
-	 * in the target.
-	 *
-	 * Note that we have to be careful to allow btree->extent conversions
-	 * (a common defrag case) which will occur when the temp inode is in
-	 * extent format...
-	 */
-	if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
-		if (XFS_IFORK_BOFF(ip) &&
-		    XFS_BMAP_BMDR_SPACE(tip->i_df.if_broot) > XFS_IFORK_BOFF(ip))
-			return EINVAL;
-		if (XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <=
-		    XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
-			return EINVAL;
-	}
-
-	/* Reciprocal target->temp btree format checks */
-	if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
-		if (XFS_IFORK_BOFF(tip) &&
-		    XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > XFS_IFORK_BOFF(tip))
-			return EINVAL;
-		if (XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <=
-		    XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
-			return EINVAL;
-	}
-
-	return 0;
-}
-
-static int
-xfs_swap_extents(
-	xfs_inode_t	*ip,	/* target inode */
-	xfs_inode_t	*tip,	/* tmp inode */
-	xfs_swapext_t	*sxp)
-{
-	xfs_mount_t	*mp = ip->i_mount;
-	xfs_trans_t	*tp;
-	xfs_bstat_t	*sbp = &sxp->sx_stat;
-	xfs_ifork_t	*tempifp, *ifp, *tifp;
-	int		src_log_flags, target_log_flags;
-	int		error = 0;
-	int		aforkblks = 0;
-	int		taforkblks = 0;
-	__uint64_t	tmp;
-
-	/*
-	 * We have no way of updating owner information in the BMBT blocks for
-	 * each inode on CRC enabled filesystems, so to avoid corrupting the
-	 * this metadata we simply don't allow extent swaps to occur.
-	 */
-	if (xfs_sb_version_hascrc(&mp->m_sb))
-		return XFS_ERROR(EINVAL);
-
-	tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
-	if (!tempifp) {
-		error = XFS_ERROR(ENOMEM);
-		goto out;
-	}
-
-	/*
-	 * we have to do two separate lock calls here to keep lockdep
-	 * happy. If we try to get all the locks in one call, lock will
-	 * report false positives when we drop the ILOCK and regain them
-	 * below.
-	 */
-	xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
-	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
-
-	/* Verify that both files have the same format */
-	if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
-		error = XFS_ERROR(EINVAL);
-		goto out_unlock;
-	}
-
-	/* Verify both files are either real-time or non-realtime */
-	if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
-		error = XFS_ERROR(EINVAL);
-		goto out_unlock;
-	}
-
-	error = -filemap_write_and_wait(VFS_I(tip)->i_mapping);
-	if (error)
-		goto out_unlock;
-	truncate_pagecache_range(VFS_I(tip), 0, -1);
-
-	/* Verify O_DIRECT for ftmp */
-	if (VN_CACHED(VFS_I(tip)) != 0) {
-		error = XFS_ERROR(EINVAL);
-		goto out_unlock;
-	}
-
-	/* Verify all data are being swapped */
-	if (sxp->sx_offset != 0 ||
-	    sxp->sx_length != ip->i_d.di_size ||
-	    sxp->sx_length != tip->i_d.di_size) {
-		error = XFS_ERROR(EFAULT);
-		goto out_unlock;
-	}
-
-	trace_xfs_swap_extent_before(ip, 0);
-	trace_xfs_swap_extent_before(tip, 1);
-
-	/* check inode formats now that data is flushed */
-	error = xfs_swap_extents_check_format(ip, tip);
-	if (error) {
-		xfs_notice(mp,
-		    "%s: inode 0x%llx format is incompatible for exchanging.",
-				__func__, ip->i_ino);
-		goto out_unlock;
-	}
-
-	/*
-	 * Compare the current change & modify times with that
-	 * passed in.  If they differ, we abort this swap.
-	 * This is the mechanism used to ensure the calling
-	 * process that the file was not changed out from
-	 * under it.
-	 */
-	if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||
-	    (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||
-	    (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||
-	    (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {
-		error = XFS_ERROR(EBUSY);
-		goto out_unlock;
-	}
-
-	/* We need to fail if the file is memory mapped.  Once we have tossed
-	 * all existing pages, the page fault will have no option
-	 * but to go to the filesystem for pages. By making the page fault call
-	 * vop_read (or write in the case of autogrow) they block on the iolock
-	 * until we have switched the extents.
-	 */
-	if (VN_MAPPED(VFS_I(ip))) {
-		error = XFS_ERROR(EBUSY);
-		goto out_unlock;
-	}
-
-	xfs_iunlock(ip, XFS_ILOCK_EXCL);
-	xfs_iunlock(tip, XFS_ILOCK_EXCL);
-
-	/*
-	 * There is a race condition here since we gave up the
-	 * ilock.  However, the data fork will not change since
-	 * we have the iolock (locked for truncation too) so we
-	 * are safe.  We don't really care if non-io related
-	 * fields change.
-	 */
-	truncate_pagecache_range(VFS_I(ip), 0, -1);
-
-	tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
-	if ((error = xfs_trans_reserve(tp, 0,
-				     XFS_ICHANGE_LOG_RES(mp), 0,
-				     0, 0))) {
-		xfs_iunlock(ip,  XFS_IOLOCK_EXCL);
-		xfs_iunlock(tip, XFS_IOLOCK_EXCL);
-		xfs_trans_cancel(tp, 0);
-		goto out;
-	}
-	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
-
-	/*
-	 * Count the number of extended attribute blocks
-	 */
-	if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
-	     (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
-		error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
-		if (error)
-			goto out_trans_cancel;
-	}
-	if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
-	     (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
-		error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
-			&taforkblks);
-		if (error)
-			goto out_trans_cancel;
-	}
-
-	/*
-	 * Swap the data forks of the inodes
-	 */
-	ifp = &ip->i_df;
-	tifp = &tip->i_df;
-	*tempifp = *ifp;	/* struct copy */
-	*ifp = *tifp;		/* struct copy */
-	*tifp = *tempifp;	/* struct copy */
-
-	/*
-	 * Fix the on-disk inode values
-	 */
-	tmp = (__uint64_t)ip->i_d.di_nblocks;
-	ip->i_d.di_nblocks = tip->i_d.di_nblocks - taforkblks + aforkblks;
-	tip->i_d.di_nblocks = tmp + taforkblks - aforkblks;
-
-	tmp = (__uint64_t) ip->i_d.di_nextents;
-	ip->i_d.di_nextents = tip->i_d.di_nextents;
-	tip->i_d.di_nextents = tmp;
-
-	tmp = (__uint64_t) ip->i_d.di_format;
-	ip->i_d.di_format = tip->i_d.di_format;
-	tip->i_d.di_format = tmp;
-
-	/*
-	 * The extents in the source inode could still contain speculative
-	 * preallocation beyond EOF (e.g. the file is open but not modified
-	 * while defrag is in progress). In that case, we need to copy over the
-	 * number of delalloc blocks the data fork in the source inode is
-	 * tracking beyond EOF so that when the fork is truncated away when the
-	 * temporary inode is unlinked we don't underrun the i_delayed_blks
-	 * counter on that inode.
-	 */
-	ASSERT(tip->i_delayed_blks == 0);
-	tip->i_delayed_blks = ip->i_delayed_blks;
-	ip->i_delayed_blks = 0;
-
-	src_log_flags = XFS_ILOG_CORE;
-	switch (ip->i_d.di_format) {
-	case XFS_DINODE_FMT_EXTENTS:
-		/* If the extents fit in the inode, fix the
-		 * pointer.  Otherwise it's already NULL or
-		 * pointing to the extent.
-		 */
-		if (ip->i_d.di_nextents <= XFS_INLINE_EXTS) {
-			ifp->if_u1.if_extents =
-				ifp->if_u2.if_inline_ext;
-		}
-		src_log_flags |= XFS_ILOG_DEXT;
-		break;
-	case XFS_DINODE_FMT_BTREE:
-		src_log_flags |= XFS_ILOG_DBROOT;
-		break;
-	}
-
-	target_log_flags = XFS_ILOG_CORE;
-	switch (tip->i_d.di_format) {
-	case XFS_DINODE_FMT_EXTENTS:
-		/* If the extents fit in the inode, fix the
-		 * pointer.  Otherwise it's already NULL or
-		 * pointing to the extent.
-		 */
-		if (tip->i_d.di_nextents <= XFS_INLINE_EXTS) {
-			tifp->if_u1.if_extents =
-				tifp->if_u2.if_inline_ext;
-		}
-		target_log_flags |= XFS_ILOG_DEXT;
-		break;
-	case XFS_DINODE_FMT_BTREE:
-		target_log_flags |= XFS_ILOG_DBROOT;
-		break;
-	}
-
-
-	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
-	xfs_trans_ijoin(tp, tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
-
-	xfs_trans_log_inode(tp, ip,  src_log_flags);
-	xfs_trans_log_inode(tp, tip, target_log_flags);
-
-	/*
-	 * If this is a synchronous mount, make sure that the
-	 * transaction goes to disk before returning to the user.
-	 */
-	if (mp->m_flags & XFS_MOUNT_WSYNC)
-		xfs_trans_set_sync(tp);
-
-	error = xfs_trans_commit(tp, 0);
-
-	trace_xfs_swap_extent_after(ip, 0);
-	trace_xfs_swap_extent_after(tip, 1);
-out:
-	kmem_free(tempifp);
-	return error;
-
-out_unlock:
-	xfs_iunlock(ip,  XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
-	xfs_iunlock(tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
-	goto out;
-
-out_trans_cancel:
-	xfs_trans_cancel(tp, 0);
-	goto out_unlock;
-}

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;
 	}