Re: [PATCH 7/8] autofs: convert autofs to use the new mount api
From: Ian Kent
Date: Fri Sep 22 2023 - 05:34:01 EST
On 22/9/23 16:31, Christian Brauner wrote:
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.
Right you are, sorry about that and thanks very much for fixing it for
me.
Ian
Ian