[PATCH 4/6] autofs - use struct for mount params

From: Ian Kent
Date: Mon Nov 12 2018 - 20:45:50 EST

Use a structure to hold parsed parameters to simplify the
autofs_parse_options() function call.

Also seperate option parsing and applying the options into
seperate functions.

Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
---
fs/autofs/inode.c | 193 ++++++++++++++++++++++++++++++++---------------------
1 file changed, 116 insertions(+), 77 deletions(-)

diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
index 93af0d5777ae..53ed6c637cbf 100644
--- a/fs/autofs/inode.c
+++ b/fs/autofs/inode.c
@@ -108,6 +108,17 @@ static const struct super_operations autofs_sops = {
.evict_inode = autofs_evict_inode,
};

+struct autofs_fs_params {
+ int pipefd;
+ kuid_t uid;
+ kgid_t gid;
+ int pgrp;
+ bool pgrp_set;
+ int min_proto;
+ int max_proto;
+ unsigned int type;
+};
+
enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
Opt_indirect, Opt_direct, Opt_offset};

@@ -124,24 +135,26 @@ static const match_table_t tokens = {
{Opt_err, NULL}
};

-static int parse_options(char *options, int *pipefd, kuid_t *uid, kgid_t *gid,
- int *pgrp, bool *pgrp_set, unsigned int *type,
- int *minproto, int *maxproto)
+static int autofs_parse_options(char *options, struct autofs_fs_params *params)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
+ kuid_t uid;
+ kgid_t gid;
+
+ if (!options)
+ return 1;

- *uid = current_uid();
- *gid = current_gid();
+ params->pipefd = -1;

- *minproto = AUTOFS_MIN_PROTO_VERSION;
- *maxproto = AUTOFS_MAX_PROTO_VERSION;
+ params->uid = current_uid();
+ params->gid = current_gid();

- *pipefd = -1;
+ params->min_proto = AUTOFS_MIN_PROTO_VERSION;
+ params->max_proto = AUTOFS_MAX_PROTO_VERSION;

- if (!options)
- return 1;
+ params->pgrp_set = false;

while ((p = strsep(&options, ",")) != NULL) {
int token;
@@ -152,53 +165,126 @@ static int parse_options(char *options, int *pipefd, kuid_t *uid, kgid_t *gid,
token = match_token(p, tokens, args);
switch (token) {
case Opt_fd:
- if (match_int(args, pipefd))
+ if (match_int(args, &option))
return 1;
+ params->pipefd = option;
break;
case Opt_uid:
if (match_int(args, &option))
return 1;
- *uid = make_kuid(current_user_ns(), option);
- if (!uid_valid(*uid))
+ uid = make_kuid(current_user_ns(), option);
+ if (!uid_valid(uid))
return 1;
+ params->uid = uid;
break;
case Opt_gid:
if (match_int(args, &option))
return 1;
- *gid = make_kgid(current_user_ns(), option);
- if (!gid_valid(*gid))
+ gid = make_kgid(current_user_ns(), option);
+ if (!gid_valid(gid))
return 1;
+ params->gid = gid;
break;
case Opt_pgrp:
if (match_int(args, &option))
return 1;
- *pgrp = option;
- *pgrp_set = true;
+ params->pgrp = option;
+ params->pgrp_set = true;
break;
case Opt_minproto:
if (match_int(args, &option))
return 1;
- *minproto = option;
+ params->min_proto = option;
break;
case Opt_maxproto:
if (match_int(args, &option))
return 1;
- *maxproto = option;
+ params->max_proto = option;
break;
case Opt_indirect:
- set_autofs_type_indirect(type);
+ set_autofs_type_indirect(&params->type);
break;
case Opt_direct:
- set_autofs_type_direct(type);
+ set_autofs_type_direct(&params->type);
break;
case Opt_offset:
- set_autofs_type_offset(type);
+ set_autofs_type_offset(&params->type);
break;
default:
return 1;
}
}
- return (*pipefd < 0);
+ return (params->pipefd < 0);
+}
+
+static int autofs_apply_sbi_options(struct autofs_sb_info *sbi,
+ struct autofs_fs_params *params)
+{
+ int err;
+
+ sbi->pipefd = params->pipefd;
+
+ if (params->type)
+ sbi->type = params->type;
+
+ /* Test versions first */
+ if (params->max_proto < AUTOFS_MIN_PROTO_VERSION ||
+ params->min_proto > AUTOFS_MAX_PROTO_VERSION) {
+ pr_err("kernel does not match daemon version\n");
+ pr_err("daemon (%d, %d) kernel (%d, %d)\n",
+ params->min_proto, params->max_proto,
+ AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
+ goto out;
+ }
+
+ sbi->max_proto = params->max_proto;
+ sbi->min_proto = params->min_proto;
+
+ if (sbi->min_proto > sbi->max_proto)
+ sbi->min_proto = params->max_proto;
+
+ /* Establish highest kernel protocol version */
+ if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
+ sbi->version = AUTOFS_MAX_PROTO_VERSION;
+ else
+ sbi->version = params->max_proto;
+
+ sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
+
+ if (!params->pgrp_set)
+ sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
+ else {
+ sbi->oz_pgrp = find_get_pid(params->pgrp);
+ if (!sbi->oz_pgrp) {
+ pr_err("could not find process group %d\n",
+ params->pgrp);
+ goto out;
+ }
+ }
+
+ pr_debug("pipe fd = %d, pgrp = %u\n",
+ sbi->pipefd, pid_nr(sbi->oz_pgrp));
+
+ sbi->pipe = fget(sbi->pipefd);
+ if (!sbi->pipe) {
+ pr_err("could not open pipe file descriptor\n");
+ goto out_put_pid;
+ }
+
+ err = autofs_prepare_pipe(sbi->pipe);
+ if (err < 0)
+ goto out_fput;
+
+ sbi->catatonic = 0;
+
+ return 0;
+
+out_fput:
+ fput(sbi->pipe);
+out_put_pid:
+ put_pid(sbi->oz_pgrp);
+out:
+ return 1;
}

static struct autofs_sb_info *autofs_alloc_sbi(struct super_block *s)
@@ -229,12 +315,9 @@ int autofs_fill_super(struct super_block *s, void *data, int silent)
{
struct inode *root_inode;
struct dentry *root;
- struct file *pipe;
- int pipefd;
+ struct autofs_fs_params params;
struct autofs_sb_info *sbi;
struct autofs_info *ino;
- int pgrp = 0;
- bool pgrp_set = false;
int ret = -EINVAL;

sbi = autofs_alloc_sbi(s);
@@ -267,45 +350,20 @@ int autofs_fill_super(struct super_block *s, void *data, int silent)
root = d_make_root(root_inode);
if (!root)
goto fail_iput;
- pipe = NULL;

root->d_fsdata = ino;

- /* Can this call block? */
- if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
- &pgrp, &pgrp_set, &sbi->type, &sbi->min_proto,
- &sbi->max_proto)) {
+ memset(&params, 0, sizeof(struct autofs_fs_params));
+ if (autofs_parse_options(data, &params)) {
pr_err("called with bogus options\n");
goto fail_dput;
}
+ root_inode->i_uid = params->uid;
+ root_inode->i_gid = params->gid;

- /* Test versions first */
- if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
- sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
- pr_err("kernel does not match daemon version "
- "daemon (%d, %d) kernel (%d, %d)\n",
- sbi->min_proto, sbi->max_proto,
- AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
+ ret = autofs_apply_sbi_options(sbi, &params);
+ if (ret)
goto fail_dput;
- }
-
- /* Establish highest kernel protocol version */
- if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
- sbi->version = AUTOFS_MAX_PROTO_VERSION;
- else
- sbi->version = sbi->max_proto;
- sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
-
- if (pgrp_set) {
- sbi->oz_pgrp = find_get_pid(pgrp);
- if (!sbi->oz_pgrp) {
- pr_err("could not find process group %d\n",
- pgrp);
- goto fail_dput;
- }
- } else {
- sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
- }

if (autofs_type_trigger(sbi->type))
__managed_dentry_set_managed(root);
@@ -313,20 +371,6 @@ int autofs_fill_super(struct super_block *s, void *data, int silent)
root_inode->i_fop = &autofs_root_operations;
root_inode->i_op = &autofs_dir_inode_operations;

- pr_debug("pipe fd = %d, pgrp = %u\n", pipefd, pid_nr(sbi->oz_pgrp));
-
- pipe = fget(pipefd);
- if (!pipe) {
- pr_err("could not open pipe file descriptor\n");
- goto fail_put_pid;
- }
- ret = autofs_prepare_pipe(pipe);
- if (ret < 0)
- goto fail_fput;
- sbi->pipe = pipe;
- sbi->pipefd = pipefd;
- sbi->catatonic = 0;
-
/*
* Success! Install the root dentry now to indicate completion.
*/
@@ -336,11 +380,6 @@ int autofs_fill_super(struct super_block *s, void *data, int silent)
/*
* Failure ... clean up.
*/
-fail_fput:
- pr_err("pipe file descriptor does not contain proper ops\n");
- fput(pipe);
-fail_put_pid:
- put_pid(sbi->oz_pgrp);
fail_dput:
dput(root);
goto fail_free;