1 files changed, 285 insertions, 0 deletions
diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c
new file mode 100644
index 000000000..69ed278dd
--- /dev/null
+++ b/fs/ocfs2/export.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * export.c
+ *
+ * Functions to facilitate NFS exporting
+ *
+ * Copyright (C) 2002, 2005 Oracle.  All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/types.h>
+
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "alloc.h"
+#include "dir.h"
+#include "dlmglue.h"
+#include "dcache.h"
+#include "export.h"
+#include "inode.h"
+
+#include "buffer_head_io.h"
+#include "suballoc.h"
+#include "ocfs2_trace.h"
+
+struct ocfs2_inode_handle
+{
+	u64 ih_blkno;
+	u32 ih_generation;
+};
+
+static struct dentry *ocfs2_get_dentry(struct super_block *sb,
+		struct ocfs2_inode_handle *handle)
+{
+	struct inode *inode;
+	struct ocfs2_super *osb = OCFS2_SB(sb);
+	u64 blkno = handle->ih_blkno;
+	int status, set;
+	struct dentry *result;
+
+	trace_ocfs2_get_dentry_begin(sb, handle, (unsigned long long)blkno);
+
+	if (blkno == 0) {
+		result = ERR_PTR(-ESTALE);
+		goto bail;
+	}
+
+	inode = ocfs2_ilookup(sb, blkno);
+	/*
+	 * If the inode exists in memory, we only need to check it's
+	 * generation number
+	 */
+	if (inode)
+		goto check_gen;
+
+	/*
+	 * This will synchronize us against ocfs2_delete_inode() on
+	 * all nodes
+	 */
+	status = ocfs2_nfs_sync_lock(osb, 1);
+	if (status < 0) {
+		mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
+		goto check_err;
+	}
+
+	status = ocfs2_test_inode_bit(osb, blkno, &set);
+	if (status < 0) {
+		if (status == -EINVAL) {
+			/*
+			 * The blkno NFS gave us doesn't even show up
+			 * as an inode, we return -ESTALE to be
+			 * nice
+			 */
+			status = -ESTALE;
+		} else
+			mlog(ML_ERROR, "test inode bit failed %d\n", status);
+		goto unlock_nfs_sync;
+	}
+
+	trace_ocfs2_get_dentry_test_bit(status, set);
+	/* If the inode allocator bit is clear, this inode must be stale */
+	if (!set) {
+		status = -ESTALE;
+		goto unlock_nfs_sync;
+	}
+
+	inode = ocfs2_iget(osb, blkno, 0, 0);
+
+unlock_nfs_sync:
+	ocfs2_nfs_sync_unlock(osb, 1);
+
+check_err:
+	if (status < 0) {
+		if (status == -ESTALE) {
+			trace_ocfs2_get_dentry_stale((unsigned long long)blkno,
+						     handle->ih_generation);
+		}
+		result = ERR_PTR(status);
+		goto bail;
+	}
+
+	if (IS_ERR(inode)) {
+		mlog_errno(PTR_ERR(inode));
+		result = ERR_CAST(inode);
+		goto bail;
+	}
+
+check_gen:
+	if (handle->ih_generation != inode->i_generation) {
+		trace_ocfs2_get_dentry_generation((unsigned long long)blkno,
+						  handle->ih_generation,
+						  inode->i_generation);
+		iput(inode);
+		result = ERR_PTR(-ESTALE);
+		goto bail;
+	}
+
+	result = d_obtain_alias(inode);
+	if (IS_ERR(result))
+		mlog_errno(PTR_ERR(result));
+
+bail:
+	trace_ocfs2_get_dentry_end(result);
+	return result;
+}
+
+static struct dentry *ocfs2_get_parent(struct dentry *child)
+{
+	int status;
+	u64 blkno;
+	struct dentry *parent;
+	struct inode *dir = d_inode(child);
+	int set;
+
+	trace_ocfs2_get_parent(child, child->d_name.len, child->d_name.name,
+			       (unsigned long long)OCFS2_I(dir)->ip_blkno);
+
+	status = ocfs2_nfs_sync_lock(OCFS2_SB(dir->i_sb), 1);
+	if (status < 0) {
+		mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
+		parent = ERR_PTR(status);
+		goto bail;
+	}
+
+	status = ocfs2_inode_lock(dir, NULL, 0);
+	if (status < 0) {
+		if (status != -ENOENT)
+			mlog_errno(status);
+		parent = ERR_PTR(status);
+		goto unlock_nfs_sync;
+	}
+
+	status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno);
+	if (status < 0) {
+		parent = ERR_PTR(-ENOENT);
+		goto bail_unlock;
+	}
+
+	status = ocfs2_test_inode_bit(OCFS2_SB(dir->i_sb), blkno, &set);
+	if (status < 0) {
+		if (status == -EINVAL) {
+			status = -ESTALE;
+		} else
+			mlog(ML_ERROR, "test inode bit failed %d\n", status);
+		parent = ERR_PTR(status);
+		goto bail_unlock;
+	}
+
+	trace_ocfs2_get_dentry_test_bit(status, set);
+	if (!set) {
+		status = -ESTALE;
+		parent = ERR_PTR(status);
+		goto bail_unlock;
+	}
+
+	parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));
+
+bail_unlock:
+	ocfs2_inode_unlock(dir, 0);
+
+unlock_nfs_sync:
+	ocfs2_nfs_sync_unlock(OCFS2_SB(dir->i_sb), 1);
+
+bail:
+	trace_ocfs2_get_parent_end(parent);
+
+	return parent;
+}
+
+static int ocfs2_encode_fh(struct inode *inode, u32 *fh_in, int *max_len,
+			   struct inode *parent)
+{
+	int len = *max_len;
+	int type = 1;
+	u64 blkno;
+	u32 generation;
+	__le32 *fh = (__force __le32 *) fh_in;
+
+#ifdef TRACE_HOOKS_ARE_NOT_BRAINDEAD_IN_YOUR_OPINION
+#error "You go ahead and fix that mess, then.  Somehow"
+	trace_ocfs2_encode_fh_begin(dentry, dentry->d_name.len,
+				    dentry->d_name.name,
+				    fh, len, connectable);
+#endif
+
+	if (parent && (len < 6)) {
+		*max_len = 6;
+		type = FILEID_INVALID;
+		goto bail;
+	} else if (len < 3) {
+		*max_len = 3;
+		type = FILEID_INVALID;
+		goto bail;
+	}
+
+	blkno = OCFS2_I(inode)->ip_blkno;
+	generation = inode->i_generation;
+
+	trace_ocfs2_encode_fh_self((unsigned long long)blkno, generation);
+
+	len = 3;
+	fh[0] = cpu_to_le32((u32)(blkno >> 32));
+	fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff));
+	fh[2] = cpu_to_le32(generation);
+
+	if (parent) {
+		blkno = OCFS2_I(parent)->ip_blkno;
+		generation = parent->i_generation;
+
+		fh[3] = cpu_to_le32((u32)(blkno >> 32));
+		fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff));
+		fh[5] = cpu_to_le32(generation);
+
+		len = 6;
+		type = 2;
+
+		trace_ocfs2_encode_fh_parent((unsigned long long)blkno,
+					     generation);
+	}
+
+	*max_len = len;
+
+bail:
+	trace_ocfs2_encode_fh_type(type);
+	return type;
+}
+
+static struct dentry *ocfs2_fh_to_dentry(struct super_block *sb,
+		struct fid *fid, int fh_len, int fh_type)
+{
+	struct ocfs2_inode_handle handle;
+
+	if (fh_len < 3 || fh_type > 2)
+		return NULL;
+
+	handle.ih_blkno = (u64)le32_to_cpu(fid->raw[0]) << 32;
+	handle.ih_blkno |= (u64)le32_to_cpu(fid->raw[1]);
+	handle.ih_generation = le32_to_cpu(fid->raw[2]);
+	return ocfs2_get_dentry(sb, &handle);
+}
+
+static struct dentry *ocfs2_fh_to_parent(struct super_block *sb,
+		struct fid *fid, int fh_len, int fh_type)
+{
+	struct ocfs2_inode_handle parent;
+
+	if (fh_type != 2 || fh_len < 6)
+		return NULL;
+
+	parent.ih_blkno = (u64)le32_to_cpu(fid->raw[3]) << 32;
+	parent.ih_blkno |= (u64)le32_to_cpu(fid->raw[4]);
+	parent.ih_generation = le32_to_cpu(fid->raw[5]);
+	return ocfs2_get_dentry(sb, &parent);
+}
+
+const struct export_operations ocfs2_export_ops = {
+	.encode_fh	= ocfs2_encode_fh,
+	.fh_to_dentry	= ocfs2_fh_to_dentry,
+	.fh_to_parent	= ocfs2_fh_to_parent,
+	.get_parent	= ocfs2_get_parent,
+};