From: Chuck Lever <chuck.lever@xxxxxxxxxx>
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 b0b0c0a26e84 ("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: Scott Mayhew <smayhew@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfsd/nfsctl.c | 74 ++++++++++++++++++++++++++++++++++++++++++------------
1 file changed, 58 insertions(+), 16 deletions(-)
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index f2a0d6ac88df..04474b8ccf0a 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -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);
