Commit 4df750c9 authored by Chuck Lever's avatar Chuck Lever
Browse files

NFSD: Replace /proc/fs/nfsd/supported_krb5_enctypes with a symlink 



Now that I've added a file under /proc/net/rpc that is managed by
the SunRPC's Kerberos mechanism, replace NFSD's
supported_krb5_enctypes file with a symlink to the new SunRPC proc
file, which contains exactly the same content.

Remarkably, commit b0b0c0a2 ("nfsd: add proc file listing
kernel's gss_krb5 enctypes") added the nfsd_supported_krb5_enctypes
file in 2011, but this file has never been documented in nfsd(7).

Tested-by: default avatarScott Mayhew <smayhew@redhat.com>
Reviewed-by: default avatarSimo Sorce <simo@redhat.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent bdb12fb1

fs/nfsd/nfsctl.c

+58 −16
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 
#include <linux/lockd/lockd.h>

#include <linux/sunrpc/addr.h>

#include <linux/sunrpc/gss_api.h>

#include <linux/sunrpc/gss_krb5_enctypes.h>

#include <linux/sunrpc/rpc_pipe_fs.h>

#include <linux/module.h>

#include <linux/fsnotify.h>
@@ -47,7 +46,6 @@ enum { 
	NFSD_MaxBlkSize,

	NFSD_MaxConnections,

	NFSD_Filecache,

	NFSD_SupportedEnctypes,

	/*

	 * The below MUST come last.  Otherwise we leave a hole in nfsd_files[]

	 * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
@@ -187,16 +185,6 @@ static int export_features_show(struct seq_file *m, void *v) 


DEFINE_SHOW_ATTRIBUTE(export_features);



#if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)

static int supported_enctypes_show(struct seq_file *m, void *v)

{

	seq_printf(m, KRB5_SUPPORTED_ENCTYPES);

	return 0;

}



DEFINE_SHOW_ATTRIBUTE(supported_enctypes);

#endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */



static const struct file_operations pool_stats_operations = {

	.open		= nfsd_pool_stats_open,

	.read		= seq_read,
@@ -1150,6 +1138,9 @@ static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode) 
		inode->i_op = &simple_dir_inode_operations;

		inc_nlink(inode);

		break;

	case S_IFLNK:

		inode->i_op = &simple_symlink_inode_operations;

		break;

	default:

		break;

	}
@@ -1195,6 +1186,59 @@ static struct dentry *nfsd_mkdir(struct dentry *parent, struct nfsdfs_client *nc 
	goto out;

}



#if IS_ENABLED(CONFIG_SUNRPC_GSS)

static int __nfsd_symlink(struct inode *dir, struct dentry *dentry,

			  umode_t mode, const char *content)

{

	struct inode *inode;



	inode = nfsd_get_inode(dir->i_sb, mode);

	if (!inode)

		return -ENOMEM;



	inode->i_link = (char *)content;

	inode->i_size = strlen(content);



	d_add(dentry, inode);

	inc_nlink(dir);

	fsnotify_create(dir, dentry);

	return 0;

}



/*

 * @content is assumed to be a NUL-terminated string that lives

 * longer than the symlink itself.

 */

static void nfsd_symlink(struct dentry *parent, const char *name,

			 const char *content)

{

	struct inode *dir = parent->d_inode;

	struct dentry *dentry;

	int ret = -ENOMEM;



	inode_lock(dir);

	dentry = d_alloc_name(parent, name);

	if (!dentry)

		goto out_err;

	ret = __nfsd_symlink(d_inode(parent), dentry, S_IFLNK | 0777, content);

	if (ret)

		goto out_err;

out:

	inode_unlock(dir);

	return;

out_err:

	dput(dentry);

	dentry = ERR_PTR(ret);

	goto out;

}

#else

static inline void nfsd_symlink(struct dentry *parent, const char *name,

				const char *content)

{

}



#endif



static void clear_ncl(struct inode *inode)

{

	struct nfsdfs_client *ncl = inode->i_private;
@@ -1355,10 +1399,6 @@ static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc) 
		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},

		[NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO},

		[NFSD_Filecache] = {"filecache", &nfsd_file_cache_stats_fops, S_IRUGO},

#if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)

		[NFSD_SupportedEnctypes] = {"supported_krb5_enctypes",

					&supported_enctypes_fops, S_IRUGO},

#endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */

#ifdef CONFIG_NFSD_V4

		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},

		[NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR},
@@ -1371,6 +1411,8 @@ static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc) 
	ret = simple_fill_super(sb, 0x6e667364, nfsd_files);

	if (ret)

		return ret;

	nfsd_symlink(sb->s_root, "supported_krb5_enctypes",

		     "/proc/net/rpc/gss_krb5_enctypes");

	dentry = nfsd_mkdir(sb->s_root, NULL, "clients");

	if (IS_ERR(dentry))

		return PTR_ERR(dentry);