v4.19.13 snapshot.
diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c
new file mode 100644
index 0000000..a332f3c
--- /dev/null
+++ b/fs/gfs2/export.c
@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License version 2.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/exportfs.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/crc32.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "dir.h"
+#include "glock.h"
+#include "glops.h"
+#include "inode.h"
+#include "super.h"
+#include "rgrp.h"
+#include "util.h"
+
+#define GFS2_SMALL_FH_SIZE 4
+#define GFS2_LARGE_FH_SIZE 8
+#define GFS2_OLD_FH_SIZE 10
+
+static int gfs2_encode_fh(struct inode *inode, __u32 *p, int *len,
+ struct inode *parent)
+{
+ __be32 *fh = (__force __be32 *)p;
+ struct super_block *sb = inode->i_sb;
+ struct gfs2_inode *ip = GFS2_I(inode);
+
+ if (parent && (*len < GFS2_LARGE_FH_SIZE)) {
+ *len = GFS2_LARGE_FH_SIZE;
+ return FILEID_INVALID;
+ } else if (*len < GFS2_SMALL_FH_SIZE) {
+ *len = GFS2_SMALL_FH_SIZE;
+ return FILEID_INVALID;
+ }
+
+ fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
+ fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
+ fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
+ fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
+ *len = GFS2_SMALL_FH_SIZE;
+
+ if (!parent || inode == d_inode(sb->s_root))
+ return *len;
+
+ ip = GFS2_I(parent);
+
+ fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
+ fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
+ fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
+ fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
+ *len = GFS2_LARGE_FH_SIZE;
+
+ return *len;
+}
+
+struct get_name_filldir {
+ struct dir_context ctx;
+ struct gfs2_inum_host inum;
+ char *name;
+};
+
+static int get_name_filldir(struct dir_context *ctx, const char *name,
+ int length, loff_t offset, u64 inum,
+ unsigned int type)
+{
+ struct get_name_filldir *gnfd =
+ container_of(ctx, struct get_name_filldir, ctx);
+
+ if (inum != gnfd->inum.no_addr)
+ return 0;
+
+ memcpy(gnfd->name, name, length);
+ gnfd->name[length] = 0;
+
+ return 1;
+}
+
+static int gfs2_get_name(struct dentry *parent, char *name,
+ struct dentry *child)
+{
+ struct inode *dir = d_inode(parent);
+ struct inode *inode = d_inode(child);
+ struct gfs2_inode *dip, *ip;
+ struct get_name_filldir gnfd = {
+ .ctx.actor = get_name_filldir,
+ .name = name
+ };
+ struct gfs2_holder gh;
+ int error;
+ struct file_ra_state f_ra = { .start = 0 };
+
+ if (!dir)
+ return -EINVAL;
+
+ if (!S_ISDIR(dir->i_mode) || !inode)
+ return -EINVAL;
+
+ dip = GFS2_I(dir);
+ ip = GFS2_I(inode);
+
+ *name = 0;
+ gnfd.inum.no_addr = ip->i_no_addr;
+ gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
+
+ error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
+ if (error)
+ return error;
+
+ error = gfs2_dir_read(dir, &gnfd.ctx, &f_ra);
+
+ gfs2_glock_dq_uninit(&gh);
+
+ if (!error && !*name)
+ error = -ENOENT;
+
+ return error;
+}
+
+static struct dentry *gfs2_get_parent(struct dentry *child)
+{
+ return d_obtain_alias(gfs2_lookupi(d_inode(child), &gfs2_qdotdot, 1));
+}
+
+static struct dentry *gfs2_get_dentry(struct super_block *sb,
+ struct gfs2_inum_host *inum)
+{
+ struct gfs2_sbd *sdp = sb->s_fs_info;
+ struct inode *inode;
+
+ inode = gfs2_lookup_by_inum(sdp, inum->no_addr, &inum->no_formal_ino,
+ GFS2_BLKST_DINODE);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+ return d_obtain_alias(inode);
+}
+
+static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type)
+{
+ struct gfs2_inum_host this;
+ __be32 *fh = (__force __be32 *)fid->raw;
+
+ switch (fh_type) {
+ case GFS2_SMALL_FH_SIZE:
+ case GFS2_LARGE_FH_SIZE:
+ case GFS2_OLD_FH_SIZE:
+ if (fh_len < GFS2_SMALL_FH_SIZE)
+ return NULL;
+ this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
+ this.no_formal_ino |= be32_to_cpu(fh[1]);
+ this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
+ this.no_addr |= be32_to_cpu(fh[3]);
+ return gfs2_get_dentry(sb, &this);
+ default:
+ return NULL;
+ }
+}
+
+static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type)
+{
+ struct gfs2_inum_host parent;
+ __be32 *fh = (__force __be32 *)fid->raw;
+
+ switch (fh_type) {
+ case GFS2_LARGE_FH_SIZE:
+ case GFS2_OLD_FH_SIZE:
+ if (fh_len < GFS2_LARGE_FH_SIZE)
+ return NULL;
+ parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
+ parent.no_formal_ino |= be32_to_cpu(fh[5]);
+ parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
+ parent.no_addr |= be32_to_cpu(fh[7]);
+ return gfs2_get_dentry(sb, &parent);
+ default:
+ return NULL;
+ }
+}
+
+const struct export_operations gfs2_export_ops = {
+ .encode_fh = gfs2_encode_fh,
+ .fh_to_dentry = gfs2_fh_to_dentry,
+ .fh_to_parent = gfs2_fh_to_parent,
+ .get_name = gfs2_get_name,
+ .get_parent = gfs2_get_parent,
+};
+