Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 314 insertions, 0 deletions

diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
new file mode 100644
index 000000000..d09bcfd7d
--- /dev/null
+++ b/fs/nfs/nfs4super.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/nfs4_mount.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_ssc.h>
+#include "delegation.h"
+#include "internal.h"
+#include "nfs4_fs.h"
+#include "nfs4idmap.h"
+#include "dns_resolve.h"
+#include "pnfs.h"
+#include "nfs.h"
+
+#define NFSDBG_FACILITY		NFSDBG_VFS
+
+static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc);
+static void nfs4_evict_inode(struct inode *inode);
+
+static const struct super_operations nfs4_sops = {
+	.alloc_inode	= nfs_alloc_inode,
+	.free_inode	= nfs_free_inode,
+	.write_inode	= nfs4_write_inode,
+	.drop_inode	= nfs_drop_inode,
+	.statfs		= nfs_statfs,
+	.evict_inode	= nfs4_evict_inode,
+	.umount_begin	= nfs_umount_begin,
+	.show_options	= nfs_show_options,
+	.show_devname	= nfs_show_devname,
+	.show_path	= nfs_show_path,
+	.show_stats	= nfs_show_stats,
+};
+
+struct nfs_subversion nfs_v4 = {
+	.owner		= THIS_MODULE,
+	.nfs_fs		= &nfs4_fs_type,
+	.rpc_vers	= &nfs_version4,
+	.rpc_ops	= &nfs_v4_clientops,
+	.sops		= &nfs4_sops,
+	.xattr		= nfs4_xattr_handlers,
+};
+
+static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	int ret = nfs_write_inode(inode, wbc);
+
+	if (ret == 0)
+		ret = pnfs_layoutcommit_inode(inode,
+				wbc->sync_mode == WB_SYNC_ALL);
+	return ret;
+}
+
+/*
+ * Clean out any remaining NFSv4 state that might be left over due
+ * to open() calls that passed nfs_atomic_lookup, but failed to call
+ * nfs_open().
+ */
+static void nfs4_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages_final(&inode->i_data);
+	clear_inode(inode);
+	/* If we are holding a delegation, return and free it */
+	nfs_inode_evict_delegation(inode);
+	/* Note that above delegreturn would trigger pnfs return-on-close */
+	pnfs_return_layout(inode);
+	pnfs_destroy_layout_final(NFS_I(inode));
+	/* First call standard NFS clear_inode() code */
+	nfs_clear_inode(inode);
+	nfs4_xattr_cache_zap(inode);
+}
+
+struct nfs_referral_count {
+	struct list_head list;
+	const struct task_struct *task;
+	unsigned int referral_count;
+};
+
+static LIST_HEAD(nfs_referral_count_list);
+static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
+
+static struct nfs_referral_count *nfs_find_referral_count(void)
+{
+	struct nfs_referral_count *p;
+
+	list_for_each_entry(p, &nfs_referral_count_list, list) {
+		if (p->task == current)
+			return p;
+	}
+	return NULL;
+}
+
+#define NFS_MAX_NESTED_REFERRALS 2
+
+static int nfs_referral_loop_protect(void)
+{
+	struct nfs_referral_count *p, *new;
+	int ret = -ENOMEM;
+
+	new = kmalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		goto out;
+	new->task = current;
+	new->referral_count = 1;
+
+	ret = 0;
+	spin_lock(&nfs_referral_count_list_lock);
+	p = nfs_find_referral_count();
+	if (p != NULL) {
+		if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
+			ret = -ELOOP;
+		else
+			p->referral_count++;
+	} else {
+		list_add(&new->list, &nfs_referral_count_list);
+		new = NULL;
+	}
+	spin_unlock(&nfs_referral_count_list_lock);
+	kfree(new);
+out:
+	return ret;
+}
+
+static void nfs_referral_loop_unprotect(void)
+{
+	struct nfs_referral_count *p;
+
+	spin_lock(&nfs_referral_count_list_lock);
+	p = nfs_find_referral_count();
+	p->referral_count--;
+	if (p->referral_count == 0)
+		list_del(&p->list);
+	else
+		p = NULL;
+	spin_unlock(&nfs_referral_count_list_lock);
+	kfree(p);
+}
+
+static int do_nfs4_mount(struct nfs_server *server,
+			 struct fs_context *fc,
+			 const char *hostname,
+			 const char *export_path)
+{
+	struct nfs_fs_context *root_ctx;
+	struct fs_context *root_fc;
+	struct vfsmount *root_mnt;
+	struct dentry *dentry;
+	size_t len;
+	int ret;
+
+	struct fs_parameter param = {
+		.key	= "source",
+		.type	= fs_value_is_string,
+		.dirfd	= -1,
+	};
+
+	if (IS_ERR(server))
+		return PTR_ERR(server);
+
+	root_fc = vfs_dup_fs_context(fc);
+	if (IS_ERR(root_fc)) {
+		nfs_free_server(server);
+		return PTR_ERR(root_fc);
+	}
+	kfree(root_fc->source);
+	root_fc->source = NULL;
+
+	root_ctx = nfs_fc2context(root_fc);
+	root_ctx->internal = true;
+	root_ctx->server = server;
+	/* We leave export_path unset as it's not used to find the root. */
+
+	len = strlen(hostname) + 5;
+	param.string = kmalloc(len, GFP_KERNEL);
+	if (param.string == NULL) {
+		put_fs_context(root_fc);
+		return -ENOMEM;
+	}
+
+	/* Does hostname needs to be enclosed in brackets? */
+	if (strchr(hostname, ':'))
+		param.size = snprintf(param.string, len, "[%s]:/", hostname);
+	else
+		param.size = snprintf(param.string, len, "%s:/", hostname);
+	ret = vfs_parse_fs_param(root_fc, &param);
+	kfree(param.string);
+	if (ret < 0) {
+		put_fs_context(root_fc);
+		return ret;
+	}
+	root_mnt = fc_mount(root_fc);
+	put_fs_context(root_fc);
+
+	if (IS_ERR(root_mnt))
+		return PTR_ERR(root_mnt);
+
+	ret = nfs_referral_loop_protect();
+	if (ret) {
+		mntput(root_mnt);
+		return ret;
+	}
+
+	dentry = mount_subtree(root_mnt, export_path);
+	nfs_referral_loop_unprotect();
+
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	fc->root = dentry;
+	return 0;
+}
+
+int nfs4_try_get_tree(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	int err;
+
+	dfprintk(MOUNT, "--> nfs4_try_get_tree()\n");
+
+	/* We create a mount for the server's root, walk to the requested
+	 * location and then create another mount for that.
+	 */
+	err= do_nfs4_mount(nfs4_create_server(fc),
+			   fc, ctx->nfs_server.hostname,
+			   ctx->nfs_server.export_path);
+	if (err) {
+		nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path");
+		dfprintk(MOUNT, "<-- nfs4_try_get_tree() = %d [error]\n", err);
+	} else {
+		dfprintk(MOUNT, "<-- nfs4_try_get_tree() = 0\n");
+	}
+	return err;
+}
+
+/*
+ * Create an NFS4 server record on referral traversal
+ */
+int nfs4_get_referral_tree(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	int err;
+
+	dprintk("--> nfs4_referral_mount()\n");
+
+	/* create a new volume representation */
+	err = do_nfs4_mount(nfs4_create_referral_server(fc),
+			    fc, ctx->nfs_server.hostname,
+			    ctx->nfs_server.export_path);
+	if (err) {
+		nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path");
+		dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = %d [error]\n", err);
+	} else {
+		dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = 0\n");
+	}
+	return err;
+}
+
+static int __init init_nfs_v4(void)
+{
+	int err;
+
+	err = nfs_dns_resolver_init();
+	if (err)
+		goto out;
+
+	err = nfs_idmap_init();
+	if (err)
+		goto out1;
+
+#ifdef CONFIG_NFS_V4_2
+	err = nfs4_xattr_cache_init();
+	if (err)
+		goto out2;
+#endif
+
+	err = nfs4_register_sysctl();
+	if (err)
+		goto out2;
+
+#ifdef CONFIG_NFS_V4_2
+	nfs42_ssc_register_ops();
+#endif
+	register_nfs_version(&nfs_v4);
+	return 0;
+out2:
+	nfs_idmap_quit();
+out1:
+	nfs_dns_resolver_destroy();
+out:
+	return err;
+}
+
+static void __exit exit_nfs_v4(void)
+{
+	/* Not called in the _init(), conditionally loaded */
+	nfs4_pnfs_v3_ds_connect_unload();
+
+	unregister_nfs_version(&nfs_v4);
+#ifdef CONFIG_NFS_V4_2
+	nfs4_xattr_cache_exit();
+	nfs42_ssc_unregister_ops();
+#endif
+	nfs4_unregister_sysctl();
+	nfs_idmap_quit();
+	nfs_dns_resolver_destroy();
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(init_nfs_v4);
+module_exit(exit_nfs_v4);