On Fri, Sep 22, 2023 at 12:12:14PM +0800, Ian Kent wrote:
> Convert the autofs filesystem to use the mount API.
>
> The conversion patch was originally written by David Howells.
> I have taken that patch and broken it into several patches in an effort
> to make the change easier to review.
>
> Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
> ---
> fs/autofs/autofs_i.h | 5 +-
> fs/autofs/init.c | 9 +-
> fs/autofs/inode.c | 247 ++++++++++++++++++++++++-------------------
> 3 files changed, 142 insertions(+), 119 deletions(-)
>
> diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h
> index c24d32be7937..244f18cdf23c 100644
> --- a/fs/autofs/autofs_i.h
> +++ b/fs/autofs/autofs_i.h
> @@ -25,6 +25,8 @@
> #include <linux/completion.h>
> #include <linux/file.h>
> #include <linux/magic.h>
> +#include <linux/fs_context.h>
> +#include <linux/fs_parser.h>
>
> /* This is the range of ioctl() numbers we claim as ours */
> #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
> @@ -205,7 +207,8 @@ static inline void managed_dentry_clear_managed(struct dentry *dentry)
>
> /* Initializing function */
>
> -int autofs_fill_super(struct super_block *, void *, int);
> +extern const struct fs_parameter_spec autofs_param_specs[];
> +int autofs_init_fs_context(struct fs_context *fc);
> struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
> void autofs_clean_ino(struct autofs_info *);
>
> diff --git a/fs/autofs/init.c b/fs/autofs/init.c
> index d3f55e874338..b5e4dfa04ed0 100644
> --- a/fs/autofs/init.c
> +++ b/fs/autofs/init.c
> @@ -7,16 +7,11 @@
> #include <linux/init.h>
> #include "autofs_i.h"
>
> -static struct dentry *autofs_mount(struct file_system_type *fs_type,
> - int flags, const char *dev_name, void *data)
> -{
> - return mount_nodev(fs_type, flags, data, autofs_fill_super);
> -}
> -
> struct file_system_type autofs_fs_type = {
> .owner = THIS_MODULE,
> .name = "autofs",
> - .mount = autofs_mount,
> + .init_fs_context = autofs_init_fs_context,
> + .parameters = autofs_param_specs,
> .kill_sb = autofs_kill_sb,
> };
> MODULE_ALIAS_FS("autofs");
> diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
> index e2026e063d8c..3f2dfed428f9 100644
> --- a/fs/autofs/inode.c
> +++ b/fs/autofs/inode.c
> @@ -6,7 +6,6 @@
>
> #include <linux/seq_file.h>
> #include <linux/pagemap.h>
> -#include <linux/parser.h>
>
> #include "autofs_i.h"
>
> @@ -111,7 +110,6 @@ static const struct super_operations autofs_sops = {
> };
>
> enum {
> - Opt_err,
> Opt_direct,
> Opt_fd,
> Opt_gid,
> @@ -125,35 +123,48 @@ enum {
> Opt_uid,
> };
>
> -static const match_table_t tokens = {
> - {Opt_fd, "fd=%u"},
> - {Opt_uid, "uid=%u"},
> - {Opt_gid, "gid=%u"},
> - {Opt_pgrp, "pgrp=%u"},
> - {Opt_minproto, "minproto=%u"},
> - {Opt_maxproto, "maxproto=%u"},
> - {Opt_indirect, "indirect"},
> - {Opt_direct, "direct"},
> - {Opt_offset, "offset"},
> - {Opt_strictexpire, "strictexpire"},
> - {Opt_ignore, "ignore"},
> - {Opt_err, NULL}
> +const struct fs_parameter_spec autofs_param_specs[] = {
> + fsparam_flag ("direct", Opt_direct),
> + fsparam_fd ("fd", Opt_fd),
> + fsparam_u32 ("gid", Opt_gid),
> + fsparam_flag ("ignore", Opt_ignore),
> + fsparam_flag ("indirect", Opt_indirect),
> + fsparam_u32 ("maxproto", Opt_maxproto),
> + fsparam_u32 ("minproto", Opt_minproto),
> + fsparam_flag ("offset", Opt_offset),
> + fsparam_u32 ("pgrp", Opt_pgrp),
> + fsparam_flag ("strictexpire", Opt_strictexpire),
> + fsparam_u32 ("uid", Opt_uid),
> + {}
> };
>
> -static int autofs_parse_fd(struct autofs_sb_info *sbi, int fd)
> +struct autofs_fs_context {
> + kuid_t uid;
> + kgid_t gid;
> + int pgrp;
> + bool pgrp_set;
> +};
> +
> +/*
> + * Open the fd. We do it here rather than in get_tree so that it's done in the
> + * context of the system call that passed the data and not the one that
> + * triggered the superblock creation, lest the fd gets reassigned.
> + */
> +static int autofs_parse_fd(struct fs_context *fc, int fd)
> {
> + struct autofs_sb_info *sbi = fc->s_fs_info;
> struct file *pipe;
> int ret;
>
> pipe = fget(fd);
> if (!pipe) {
> - pr_err("could not open pipe file descriptor\n");
> + errorf(fc, "could not open pipe file descriptor");
> return -EBADF;
> }
>
> ret = autofs_check_pipe(pipe);
> if (ret < 0) {
> - pr_err("Invalid/unusable pipe\n");
> + errorf(fc, "Invalid/unusable pipe");
> fput(pipe);
> return -EBADF;
> }
> @@ -167,58 +178,43 @@ static int autofs_parse_fd(struct autofs_sb_info *sbi, int fd)
> return 0;
> }
>
> -static int autofs_parse_param(char *optstr, struct inode *root,
> - int *pgrp, bool *pgrp_set,
> - struct autofs_sb_info *sbi)
> +static int autofs_parse_param(struct fs_context *fc, struct fs_parameter *param)
> {
> - substring_t args[MAX_OPT_ARGS];
> - int option;
> - int pipefd = -1;
> + struct autofs_fs_context *ctx = fc->fs_private;
> + struct autofs_sb_info *sbi = fc->s_fs_info;
> + struct fs_parse_result result;
> kuid_t uid;
> kgid_t gid;
> - int token;
> - int ret;
> + int opt;
>
> - token = match_token(optstr, tokens, args);
> - switch (token) {
> + opt = fs_parse(fc, autofs_param_specs, param, &result);
> + if (opt < 0)
> + return opt;
> +
> + switch (opt) {
> case Opt_fd:
> - if (match_int(args, &pipefd))
> - return 1;
> - ret = autofs_parse_fd(sbi, pipefd);
> - if (ret)
> - return 1;
> - break;
> + return autofs_parse_fd(fc, result.int_32);
> case Opt_uid:
> - if (match_int(args, &option))
> - return 1;
> - uid = make_kuid(current_user_ns(), option);
> + uid = make_kuid(current_user_ns(), result.uint_32);
> if (!uid_valid(uid))
> return 1;
This and the make_kgid() instance below need to return -EINVAL or use
invalfc() to return an error message. I can fix this up though so no
need to resend for this.
