[PATCH 05/14] ramfs: Implement show_options

From: David Howells
Date: Wed Jul 05 2017 - 11:27:50 EST


Implement the show_options superblock op for ramfs as part of a bid to get
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/ramfs/inode.c | 32 +++++++++++++++++++++-----------
1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index 26e45863e499..11201b2d06b9 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -38,6 +38,14 @@
#include <linux/uaccess.h>
#include "internal.h"

+struct ramfs_mount_opts {
+ umode_t mode;
+};
+
+struct ramfs_fs_info {
+ struct ramfs_mount_opts mount_opts;
+};
+
#define RAMFS_DEFAULT_MODE 0755

static const struct super_operations ramfs_ops;
@@ -149,14 +157,22 @@ static const struct inode_operations ramfs_dir_inode_operations = {
.rename = simple_rename,
};

+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int ramfs_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct ramfs_fs_info *fsi = root->d_sb->s_fs_info;
+
+ if (fsi->mount_opts.mode != RAMFS_DEFAULT_MODE)
+ seq_printf(m, ",mode=%o", fsi->mount_opts.mode);
+ return 0;
+}
+
static const struct super_operations ramfs_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
- .show_options = generic_show_options,
-};
-
-struct ramfs_mount_opts {
- umode_t mode;
+ .show_options = ramfs_show_options,
};

enum {
@@ -169,10 +185,6 @@ static const match_table_t tokens = {
{Opt_err, NULL}
};

-struct ramfs_fs_info {
- struct ramfs_mount_opts mount_opts;
-};
-
static int ramfs_parse_options(char *data, struct ramfs_mount_opts *opts)
{
substring_t args[MAX_OPT_ARGS];
@@ -211,8 +223,6 @@ int ramfs_fill_super(struct super_block *sb, void *data, int silent)
struct inode *inode;
int err;

- save_mount_options(sb, data);
-
fsi = kzalloc(sizeof(struct ramfs_fs_info), GFP_KERNEL);
sb->s_fs_info = fsi;
if (!fsi)