fs/nfs/nfs4super.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
  */
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/nfs_idmap.h>
 #include <linux/nfs4_mount.h>
 #include <linux/nfs_fs.h>
 #include "delegation.h"
 #include "internal.h"
 #include "nfs4_fs.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 struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *raw_data);
 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *raw_data);
 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *raw_data);

 static struct file_system_type nfs4_remote_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "nfs4",
 	.mount		= nfs4_remote_mount,
 	.kill_sb	= nfs_kill_super,
 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 };

 static struct file_system_type nfs4_remote_referral_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "nfs4",
 	.mount		= nfs4_remote_referral_mount,
 	.kill_sb	= nfs_kill_super,
 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 };

 struct file_system_type nfs4_referral_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "nfs4",
 	.mount		= nfs4_referral_mount,
 	.kill_sb	= nfs_kill_super,
 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 };

 static const struct super_operations nfs4_sops = {
 	.alloc_inode	= nfs_alloc_inode,
 	.destroy_inode	= nfs_destroy_inode,
 	.write_inode	= nfs4_write_inode,
 	.drop_inode	= nfs_drop_inode,
 	.put_super	= nfs_put_super,
 	.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,
 	.remount_fs	= nfs_remount,
 };

 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);
 	pnfs_return_layout(inode);
 	pnfs_destroy_layout(NFS_I(inode));
 	/* If we are holding a delegation, return it! */
 	nfs_inode_return_delegation_noreclaim(inode);
 	/* First call standard NFS clear_inode() code */
 	nfs_clear_inode(inode);
 }

 /*
  * Get the superblock for the NFS4 root partition
  */
 static struct dentry *
 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
 		  const char *dev_name, void *info)
 {
 	struct nfs_mount_info *mount_info = info;
 	struct nfs_server *server;
 	struct dentry *mntroot = ERR_PTR(-ENOMEM);

 	mount_info->set_security = nfs_set_sb_security;

 	/* Get a volume representation */
 	server = nfs4_create_server(mount_info, &nfs_v4);
 	if (IS_ERR(server)) {
 		mntroot = ERR_CAST(server);
 		goto out;
 	}

 	mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4);

 out:
 	return mntroot;
 }

 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
 		int flags, void *data, const char *hostname)
 {
 	struct vfsmount *root_mnt;
 	char *root_devname;
 	size_t len;

 	len = strlen(hostname) + 5;
 	root_devname = kmalloc(len, GFP_KERNEL);
 	if (root_devname == NULL)
 		return ERR_PTR(-ENOMEM);
 	/* Does hostname needs to be enclosed in brackets? */
 	if (strchr(hostname, ':'))
 		snprintf(root_devname, len, "[%s]:/", hostname);
 	else
 		snprintf(root_devname, len, "%s:/", hostname);
 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
 	kfree(root_devname);
 	return root_mnt;
 }

 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 struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
 		const char *export_path)
 {
 	struct dentry *dentry;
 	int err;

 	if (IS_ERR(root_mnt))
 		return ERR_CAST(root_mnt);

 	err = nfs_referral_loop_protect();
 	if (err) {
 		mntput(root_mnt);
 		return ERR_PTR(err);
 	}

 	dentry = mount_subtree(root_mnt, export_path);
 	nfs_referral_loop_unprotect();

 	return dentry;
 }

 struct dentry *nfs4_try_mount(int flags, const char *dev_name,
 			      struct nfs_mount_info *mount_info,
 			      struct nfs_subversion *nfs_mod)
 {
 	char *export_path;
 	struct vfsmount *root_mnt;
 	struct dentry *res;
 	struct nfs_parsed_mount_data *data = mount_info->parsed;

 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");

 	export_path = data->nfs_server.export_path;
 	data->nfs_server.export_path = "/";
 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
 			data->nfs_server.hostname);
 	data->nfs_server.export_path = export_path;

 	res = nfs_follow_remote_path(root_mnt, export_path);

 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n",
 		 PTR_ERR_OR_ZERO(res),
 		 IS_ERR(res) ? " [error]" : "");
 	return res;
 }

 static struct dentry *
 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
 			   const char *dev_name, void *raw_data)
 {
 	struct nfs_mount_info mount_info = {
 		.fill_super = nfs_fill_super,
 		.set_security = nfs_clone_sb_security,
 		.cloned = raw_data,
 	};
 	struct nfs_server *server;
 	struct dentry *mntroot = ERR_PTR(-ENOMEM);

 	dprintk("--> nfs4_referral_get_sb()\n");

 	mount_info.mntfh = nfs_alloc_fhandle();
 	if (mount_info.cloned == NULL || mount_info.mntfh == NULL)
 		goto out;

 	/* create a new volume representation */
 	server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh);
 	if (IS_ERR(server)) {
 		mntroot = ERR_CAST(server);
 		goto out;
 	}

 	mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4);
 out:
 	nfs_free_fhandle(mount_info.mntfh);
 	return mntroot;
 }

 /*
  * Create an NFS4 server record on referral traversal
  */
 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
 		int flags, const char *dev_name, void *raw_data)
 {
 	struct nfs_clone_mount *data = raw_data;
 	char *export_path;
 	struct vfsmount *root_mnt;
 	struct dentry *res;

 	dprintk("--> nfs4_referral_mount()\n");

 	export_path = data->mnt_path;
 	data->mnt_path = "/";

 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
 			flags, data, data->hostname);
 	data->mnt_path = export_path;

 	res = nfs_follow_remote_path(root_mnt, export_path);
 	dprintk("<-- nfs4_referral_mount() = %d%s\n",
 		PTR_ERR_OR_ZERO(res),
 		IS_ERR(res) ? " [error]" : "");
 	return res;
 }


 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;

 	err = nfs4_register_sysctl();
 	if (err)
 		goto out2;

 	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);
 	nfs4_unregister_sysctl();
 	nfs_idmap_quit();
 	nfs_dns_resolver_destroy();
 }

 MODULE_LICENSE("GPL");

 module_init(init_nfs_v4);
 module_exit(exit_nfs_v4);
	/*
	* Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
	*/
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/nfs_idmap.h>
	#include <linux/nfs4_mount.h>
	#include <linux/nfs_fs.h>
	#include "delegation.h"
	#include "internal.h"
	#include "nfs4_fs.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 struct dentry nfs4_remote_mount(struct file_system_type fs_type,
	int flags, const char dev_name, void raw_data);
	static struct dentry nfs4_referral_mount(struct file_system_type fs_type,
	int flags, const char dev_name, void raw_data);
	static struct dentry nfs4_remote_referral_mount(struct file_system_type fs_type,
	int flags, const char dev_name, void raw_data);

	static struct file_system_type nfs4_remote_fs_type = {
	.owner = THIS_MODULE,
	.name = "nfs4",
	.mount = nfs4_remote_mount,
	.kill_sb = nfs_kill_super,
	.fs_flags = FS_RENAME_DOES_D_MOVE\|FS_BINARY_MOUNTDATA,
	};

	static struct file_system_type nfs4_remote_referral_fs_type = {
	.owner = THIS_MODULE,
	.name = "nfs4",
	.mount = nfs4_remote_referral_mount,
	.kill_sb = nfs_kill_super,
	.fs_flags = FS_RENAME_DOES_D_MOVE\|FS_BINARY_MOUNTDATA,
	};

	struct file_system_type nfs4_referral_fs_type = {
	.owner = THIS_MODULE,
	.name = "nfs4",
	.mount = nfs4_referral_mount,
	.kill_sb = nfs_kill_super,
	.fs_flags = FS_RENAME_DOES_D_MOVE\|FS_BINARY_MOUNTDATA,
	};

	static const struct super_operations nfs4_sops = {
	.alloc_inode = nfs_alloc_inode,
	.destroy_inode = nfs_destroy_inode,
	.write_inode = nfs4_write_inode,
	.drop_inode = nfs_drop_inode,
	.put_super = nfs_put_super,
	.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,
	.remount_fs = nfs_remount,
	};

	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);
	pnfs_return_layout(inode);
	pnfs_destroy_layout(NFS_I(inode));
	/* If we are holding a delegation, return it! */
	nfs_inode_return_delegation_noreclaim(inode);
	/* First call standard NFS clear_inode() code */
	nfs_clear_inode(inode);
	}

	/*
	* Get the superblock for the NFS4 root partition
	*/
	static struct dentry *
	nfs4_remote_mount(struct file_system_type *fs_type, int flags,
	const char dev_name, void info)
	{
	struct nfs_mount_info *mount_info = info;
	struct nfs_server *server;
	struct dentry *mntroot = ERR_PTR(-ENOMEM);

	mount_info->set_security = nfs_set_sb_security;

	/* Get a volume representation */
	server = nfs4_create_server(mount_info, &nfs_v4);
	if (IS_ERR(server)) {
	mntroot = ERR_CAST(server);
	goto out;
	}

	mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4);

	out:
	return mntroot;
	}

	static struct vfsmount nfs_do_root_mount(struct file_system_type fs_type,
	int flags, void data, const char hostname)
	{
	struct vfsmount *root_mnt;
	char *root_devname;
	size_t len;

	len = strlen(hostname) + 5;
	root_devname = kmalloc(len, GFP_KERNEL);
	if (root_devname == NULL)
	return ERR_PTR(-ENOMEM);
	/* Does hostname needs to be enclosed in brackets? */
	if (strchr(hostname, ':'))
	snprintf(root_devname, len, "[%s]:/", hostname);
	else
	snprintf(root_devname, len, "%s:/", hostname);
	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
	kfree(root_devname);
	return root_mnt;
	}

	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 struct dentry nfs_follow_remote_path(struct vfsmount root_mnt,
	const char *export_path)
	{
	struct dentry *dentry;
	int err;

	if (IS_ERR(root_mnt))
	return ERR_CAST(root_mnt);

	err = nfs_referral_loop_protect();
	if (err) {
	mntput(root_mnt);
	return ERR_PTR(err);
	}

	dentry = mount_subtree(root_mnt, export_path);
	nfs_referral_loop_unprotect();

	return dentry;
	}

	struct dentry nfs4_try_mount(int flags, const char dev_name,
	struct nfs_mount_info *mount_info,
	struct nfs_subversion *nfs_mod)
	{
	char *export_path;
	struct vfsmount *root_mnt;
	struct dentry *res;
	struct nfs_parsed_mount_data *data = mount_info->parsed;

	dfprintk(MOUNT, "--> nfs4_try_mount()\n");

	export_path = data->nfs_server.export_path;
	data->nfs_server.export_path = "/";
	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
	data->nfs_server.hostname);
	data->nfs_server.export_path = export_path;

	res = nfs_follow_remote_path(root_mnt, export_path);

	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n",
	PTR_ERR_OR_ZERO(res),
	IS_ERR(res) ? " [error]" : "");
	return res;
	}

	static struct dentry *
	nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
	const char dev_name, void raw_data)
	{
	struct nfs_mount_info mount_info = {
	.fill_super = nfs_fill_super,
	.set_security = nfs_clone_sb_security,
	.cloned = raw_data,
	};
	struct nfs_server *server;
	struct dentry *mntroot = ERR_PTR(-ENOMEM);

	dprintk("--> nfs4_referral_get_sb()\n");

	mount_info.mntfh = nfs_alloc_fhandle();
	if (mount_info.cloned == NULL \|\| mount_info.mntfh == NULL)
	goto out;

	/* create a new volume representation */
	server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh);
	if (IS_ERR(server)) {
	mntroot = ERR_CAST(server);
	goto out;
	}

	mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4);
	out:
	nfs_free_fhandle(mount_info.mntfh);
	return mntroot;
	}

	/*
	* Create an NFS4 server record on referral traversal
	*/
	static struct dentry nfs4_referral_mount(struct file_system_type fs_type,
	int flags, const char dev_name, void raw_data)
	{
	struct nfs_clone_mount *data = raw_data;
	char *export_path;
	struct vfsmount *root_mnt;
	struct dentry *res;

	dprintk("--> nfs4_referral_mount()\n");

	export_path = data->mnt_path;
	data->mnt_path = "/";

	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
	flags, data, data->hostname);
	data->mnt_path = export_path;

	res = nfs_follow_remote_path(root_mnt, export_path);
	dprintk("<-- nfs4_referral_mount() = %d%s\n",
	PTR_ERR_OR_ZERO(res),
	IS_ERR(res) ? " [error]" : "");
	return res;
	}


	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;

	err = nfs4_register_sysctl();
	if (err)
	goto out2;

	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);
	nfs4_unregister_sysctl();
	nfs_idmap_quit();
	nfs_dns_resolver_destroy();
	}

	MODULE_LICENSE("GPL");

	module_init(init_nfs_v4);
	module_exit(exit_nfs_v4);