1 files changed, 250 insertions, 0 deletions
diff --git a/fs/xfs/xfs_export.c b/fs/xfs/xfs_export.c
new file mode 100644
index 00000000000..75e5d322e48
--- /dev/null
+++ b/fs/xfs/xfs_export.c
@@ -0,0 +1,250 @@
+/*
+ * Copyright (c) 2004-2005 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
+ */
+#include "xfs.h"
+#include "xfs_types.h"
+#include "xfs_inum.h"
+#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_dir2.h"
+#include "xfs_mount.h"
+#include "xfs_export.h"
+#include "xfs_vnodeops.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_inode.h"
+#include "xfs_inode_item.h"
+#include "xfs_trace.h"
+
+/*
+ * Note that we only accept fileids which are long enough rather than allow
+ * the parent generation number to default to zero.  XFS considers zero a
+ * valid generation number not an invalid/wildcard value.
+ */
+static int xfs_fileid_length(int fileid_type)
+{
+	switch (fileid_type) {
+	case FILEID_INO32_GEN:
+		return 2;
+	case FILEID_INO32_GEN_PARENT:
+		return 4;
+	case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
+		return 3;
+	case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+		return 6;
+	}
+	return 255; /* invalid */
+}
+
+STATIC int
+xfs_fs_encode_fh(
+	struct dentry		*dentry,
+	__u32			*fh,
+	int			*max_len,
+	int			connectable)
+{
+	struct fid		*fid = (struct fid *)fh;
+	struct xfs_fid64	*fid64 = (struct xfs_fid64 *)fh;
+	struct inode		*inode = dentry->d_inode;
+	int			fileid_type;
+	int			len;
+
+	/* Directories don't need their parent encoded, they have ".." */
+	if (S_ISDIR(inode->i_mode) || !connectable)
+		fileid_type = FILEID_INO32_GEN;
+	else
+		fileid_type = FILEID_INO32_GEN_PARENT;
+
+	/*
+	 * If the the filesystem may contain 64bit inode numbers, we need
+	 * to use larger file handles that can represent them.
+	 *
+	 * While we only allocate inodes that do not fit into 32 bits any
+	 * large enough filesystem may contain them, thus the slightly
+	 * confusing looking conditional below.
+	 */
+	if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) ||
+	    (XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
+		fileid_type |= XFS_FILEID_TYPE_64FLAG;
+
+	/*
+	 * Only encode if there is enough space given.  In practice
+	 * this means we can't export a filesystem with 64bit inodes
+	 * over NFSv2 with the subtree_check export option; the other
+	 * seven combinations work.  The real answer is "don't use v2".
+	 */
+	len = xfs_fileid_length(fileid_type);
+	if (*max_len < len) {
+		*max_len = len;
+		return 255;
+	}
+	*max_len = len;
+
+	switch (fileid_type) {
+	case FILEID_INO32_GEN_PARENT:
+		spin_lock(&dentry->d_lock);
+		fid->i32.parent_ino = dentry->d_parent->d_inode->i_ino;
+		fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation;
+		spin_unlock(&dentry->d_lock);
+		/*FALLTHRU*/
+	case FILEID_INO32_GEN:
+		fid->i32.ino = inode->i_ino;
+		fid->i32.gen = inode->i_generation;
+		break;
+	case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+		spin_lock(&dentry->d_lock);
+		fid64->parent_ino = dentry->d_parent->d_inode->i_ino;
+		fid64->parent_gen = dentry->d_parent->d_inode->i_generation;
+		spin_unlock(&dentry->d_lock);
+		/*FALLTHRU*/
+	case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
+		fid64->ino = inode->i_ino;
+		fid64->gen = inode->i_generation;
+		break;
+	}
+
+	return fileid_type;
+}
+
+STATIC struct inode *
+xfs_nfs_get_inode(
+	struct super_block	*sb,
+	u64			ino,
+	u32			generation)
+ {
+ 	xfs_mount_t		*mp = XFS_M(sb);
+	xfs_inode_t		*ip;
+	int			error;
+
+	/*
+	 * NFS can sometimes send requests for ino 0.  Fail them gracefully.
+	 */
+	if (ino == 0)
+		return ERR_PTR(-ESTALE);
+
+	/*
+	 * The XFS_IGET_UNTRUSTED means that an invalid inode number is just
+	 * fine and not an indication of a corrupted filesystem as clients can
+	 * send invalid file handles and we have to handle it gracefully..
+	 */
+	error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
+	if (error) {
+		/*
+		 * EINVAL means the inode cluster doesn't exist anymore.
+		 * This implies the filehandle is stale, so we should
+		 * translate it here.
+		 * We don't use ESTALE directly down the chain to not
+		 * confuse applications using bulkstat that expect EINVAL.
+		 */
+		if (error == EINVAL || error == ENOENT)
+			error = ESTALE;
+		return ERR_PTR(-error);
+	}
+
+	if (ip->i_d.di_gen != generation) {
+		IRELE(ip);
+		return ERR_PTR(-ESTALE);
+	}
+
+	return VFS_I(ip);
+}
+
+STATIC struct dentry *
+xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+		 int fh_len, int fileid_type)
+{
+	struct xfs_fid64	*fid64 = (struct xfs_fid64 *)fid;
+	struct inode		*inode = NULL;
+
+	if (fh_len < xfs_fileid_length(fileid_type))
+		return NULL;
+
+	switch (fileid_type) {
+	case FILEID_INO32_GEN_PARENT:
+	case FILEID_INO32_GEN:
+		inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
+		break;
+	case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+	case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
+		inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
+		break;
+	}
+
+	return d_obtain_alias(inode);
+}
+
+STATIC struct dentry *
+xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
+		 int fh_len, int fileid_type)
+{
+	struct xfs_fid64	*fid64 = (struct xfs_fid64 *)fid;
+	struct inode		*inode = NULL;
+
+	switch (fileid_type) {
+	case FILEID_INO32_GEN_PARENT:
+		inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
+					      fid->i32.parent_gen);
+		break;
+	case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+		inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
+					      fid64->parent_gen);
+		break;
+	}
+
+	return d_obtain_alias(inode);
+}
+
+STATIC struct dentry *
+xfs_fs_get_parent(
+	struct dentry		*child)
+{
+	int			error;
+	struct xfs_inode	*cip;
+
+	error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL);
+	if (unlikely(error))
+		return ERR_PTR(-error);
+
+	return d_obtain_alias(VFS_I(cip));
+}
+
+STATIC int
+xfs_fs_nfs_commit_metadata(
+	struct inode		*inode)
+{
+	struct xfs_inode	*ip = XFS_I(inode);
+	struct xfs_mount	*mp = ip->i_mount;
+	int			error = 0;
+
+	xfs_ilock(ip, XFS_ILOCK_SHARED);
+	if (xfs_ipincount(ip)) {
+		error = _xfs_log_force_lsn(mp, ip->i_itemp->ili_last_lsn,
+				XFS_LOG_SYNC, NULL);
+	}
+	xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+	return error;
+}
+
+const struct export_operations xfs_export_operations = {
+	.encode_fh		= xfs_fs_encode_fh,
+	.fh_to_dentry		= xfs_fs_fh_to_dentry,
+	.fh_to_parent		= xfs_fs_fh_to_parent,
+	.get_parent		= xfs_fs_get_parent,
+	.commit_metadata	= xfs_fs_nfs_commit_metadata,
+};