befs: convert befs to use the new mount api

Convert the befs filesystem to use the new mount API.
Tested by comparing random mount & remount options before and after
the change.

Cc: Luis de Bethencourt <luisbg@kernel.org>
Cc: Salah Triki <salah.triki@gmail.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Link: https://lore.kernel.org/r/20240916172735.866916-4-sandeen@redhat.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Eric Sandeen 2024-09-16 13:26:20 -04:00 committed by Christian Brauner
parent de25e36d83
commit c3099e72bf
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@ -11,12 +11,13 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/nls.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <linux/parser.h>
#include <linux/namei.h>
#include <linux/sched.h>
#include <linux/cred.h>
@ -54,22 +55,20 @@ static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
char **out, int *out_len);
static void befs_put_super(struct super_block *);
static int befs_remount(struct super_block *, int *, char *);
static int befs_statfs(struct dentry *, struct kstatfs *);
static int befs_show_options(struct seq_file *, struct dentry *);
static int parse_options(char *, struct befs_mount_options *);
static struct dentry *befs_fh_to_dentry(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type);
static struct dentry *befs_fh_to_parent(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type);
static struct dentry *befs_get_parent(struct dentry *child);
static void befs_free_fc(struct fs_context *fc);
static const struct super_operations befs_sops = {
.alloc_inode = befs_alloc_inode, /* allocate a new inode */
.free_inode = befs_free_inode, /* deallocate an inode */
.put_super = befs_put_super, /* uninit super */
.statfs = befs_statfs, /* statfs */
.remount_fs = befs_remount,
.show_options = befs_show_options,
};
@ -672,92 +671,53 @@ static struct dentry *befs_get_parent(struct dentry *child)
}
enum {
Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
Opt_uid, Opt_gid, Opt_charset, Opt_debug,
};
static const match_table_t befs_tokens = {
{Opt_uid, "uid=%d"},
{Opt_gid, "gid=%d"},
{Opt_charset, "iocharset=%s"},
{Opt_debug, "debug"},
{Opt_err, NULL}
static const struct fs_parameter_spec befs_param_spec[] = {
fsparam_uid ("uid", Opt_uid),
fsparam_gid ("gid", Opt_gid),
fsparam_string ("iocharset", Opt_charset),
fsparam_flag ("debug", Opt_debug),
{}
};
static int
parse_options(char *options, struct befs_mount_options *opts)
befs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
kuid_t uid;
kgid_t gid;
struct befs_mount_options *opts = fc->fs_private;
int token;
struct fs_parse_result result;
/* Initialize options */
opts->uid = GLOBAL_ROOT_UID;
opts->gid = GLOBAL_ROOT_GID;
opts->use_uid = 0;
opts->use_gid = 0;
opts->iocharset = NULL;
opts->debug = 0;
/* befs ignores all options on remount */
if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
return 0;
if (!options)
return 1;
token = fs_parse(fc, befs_param_spec, param, &result);
if (token < 0)
return token;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, befs_tokens, args);
switch (token) {
case Opt_uid:
if (match_int(&args[0], &option))
return 0;
uid = INVALID_UID;
if (option >= 0)
uid = make_kuid(current_user_ns(), option);
if (!uid_valid(uid)) {
pr_err("Invalid uid %d, "
"using default\n", option);
break;
}
opts->uid = uid;
opts->use_uid = 1;
break;
case Opt_gid:
if (match_int(&args[0], &option))
return 0;
gid = INVALID_GID;
if (option >= 0)
gid = make_kgid(current_user_ns(), option);
if (!gid_valid(gid)) {
pr_err("Invalid gid %d, "
"using default\n", option);
break;
}
opts->gid = gid;
opts->use_gid = 1;
break;
case Opt_charset:
kfree(opts->iocharset);
opts->iocharset = match_strdup(&args[0]);
if (!opts->iocharset) {
pr_err("allocation failure for "
"iocharset string\n");
return 0;
}
break;
case Opt_debug:
opts->debug = 1;
break;
default:
pr_err("Unrecognized mount option \"%s\" "
"or missing value\n", p);
return 0;
}
switch (token) {
case Opt_uid:
opts->uid = result.uid;
opts->use_uid = 1;
break;
case Opt_gid:
opts->gid = result.gid;
opts->use_gid = 1;
break;
case Opt_charset:
kfree(opts->iocharset);
opts->iocharset = param->string;
param->string = NULL;
break;
case Opt_debug:
opts->debug = 1;
break;
default:
return -EINVAL;
}
return 1;
return 0;
}
static int befs_show_options(struct seq_file *m, struct dentry *root)
@ -793,6 +753,21 @@ befs_put_super(struct super_block *sb)
sb->s_fs_info = NULL;
}
/*
* Copy the parsed options into the sbi mount_options member
*/
static void
befs_set_options(struct befs_sb_info *sbi, struct befs_mount_options *opts)
{
sbi->mount_opts.uid = opts->uid;
sbi->mount_opts.gid = opts->gid;
sbi->mount_opts.use_uid = opts->use_uid;
sbi->mount_opts.use_gid = opts->use_gid;
sbi->mount_opts.debug = opts->debug;
sbi->mount_opts.iocharset = opts->iocharset;
opts->iocharset = NULL;
}
/* Allocate private field of the superblock, fill it.
*
* Finish filling the public superblock fields
@ -800,7 +775,7 @@ befs_put_super(struct super_block *sb)
* Load a set of NLS translations if needed.
*/
static int
befs_fill_super(struct super_block *sb, void *data, int silent)
befs_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct buffer_head *bh;
struct befs_sb_info *befs_sb;
@ -810,6 +785,8 @@ befs_fill_super(struct super_block *sb, void *data, int silent)
const unsigned long sb_block = 0;
const off_t x86_sb_off = 512;
int blocksize;
struct befs_mount_options *parsed_opts = fc->fs_private;
int silent = fc->sb_flags & SB_SILENT;
sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
if (sb->s_fs_info == NULL)
@ -817,11 +794,7 @@ befs_fill_super(struct super_block *sb, void *data, int silent)
befs_sb = BEFS_SB(sb);
if (!parse_options((char *) data, &befs_sb->mount_opts)) {
if (!silent)
befs_error(sb, "cannot parse mount options");
goto unacquire_priv_sbp;
}
befs_set_options(befs_sb, parsed_opts);
befs_debug(sb, "---> %s", __func__);
@ -934,10 +907,10 @@ befs_fill_super(struct super_block *sb, void *data, int silent)
}
static int
befs_remount(struct super_block *sb, int *flags, char *data)
befs_reconfigure(struct fs_context *fc)
{
sync_filesystem(sb);
if (!(*flags & SB_RDONLY))
sync_filesystem(fc->root->d_sb);
if (!(fc->sb_flags & SB_RDONLY))
return -EINVAL;
return 0;
}
@ -965,19 +938,51 @@ befs_statfs(struct dentry *dentry, struct kstatfs *buf)
return 0;
}
static struct dentry *
befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
void *data)
static int befs_get_tree(struct fs_context *fc)
{
return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
return get_tree_bdev(fc, befs_fill_super);
}
static const struct fs_context_operations befs_context_ops = {
.parse_param = befs_parse_param,
.get_tree = befs_get_tree,
.reconfigure = befs_reconfigure,
.free = befs_free_fc,
};
static int befs_init_fs_context(struct fs_context *fc)
{
struct befs_mount_options *opts;
opts = kzalloc(sizeof(*opts), GFP_KERNEL);
if (!opts)
return -ENOMEM;
/* Initialize options */
opts->uid = GLOBAL_ROOT_UID;
opts->gid = GLOBAL_ROOT_GID;
fc->fs_private = opts;
fc->ops = &befs_context_ops;
return 0;
}
static void befs_free_fc(struct fs_context *fc)
{
struct befs_mount_options *opts = fc->fs_private;
kfree(opts->iocharset);
kfree(fc->fs_private);
}
static struct file_system_type befs_fs_type = {
.owner = THIS_MODULE,
.name = "befs",
.mount = befs_mount,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
.init_fs_context = befs_init_fs_context,
.parameters = befs_param_spec,
};
MODULE_ALIAS_FS("befs");