Skip to content

Commit

Permalink
ovl: factor out ovl_parse_options() helper
Browse files Browse the repository at this point in the history 
For parsing a single mount option.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
  • Loading branch information
Amir Goldstein committed Jun 19, 2023
1 parent af5f239 commit ac51962
Show file tree
Hide file tree
Showing 2 changed files with 135 additions and 116 deletions.
8 changes: 8 additions & 0 deletions fs/overlayfs/overlayfs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -70,6 +70,14 @@ enum {
OVL_XINO_ON,
};

/* The set of options that user requested explicitly via mount options */
struct ovl_opt_set {
bool metacopy;
bool redirect;
bool nfs_export;
bool index;
};

/*
* The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
* where:
Expand Down
243 changes: 127 additions & 116 deletions fs/overlayfs/super.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -514,131 +514,142 @@ static char *ovl_next_opt(char **s)
return sbegin;
}

static int ovl_parse_opt(char *opt, struct ovl_config *config)
static int ovl_parse_opt(char *opt, struct ovl_config *config,
struct ovl_opt_set *set)
{
char *p;
bool metacopy_opt = false, redirect_opt = false;
bool nfs_export_opt = false, index_opt = false;

while ((p = ovl_next_opt(&opt)) != NULL) {
int token;
substring_t args[MAX_OPT_ARGS];

if (!*p)
continue;
int err = 0;
int token;
substring_t args[MAX_OPT_ARGS];

token = match_token(p, ovl_tokens, args);
switch (token) {
case OPT_UPPERDIR:
kfree(config->upperdir);
config->upperdir = match_strdup(&args[0]);
if (!config->upperdir)
return -ENOMEM;
break;
if (!*opt)
return 0;

case OPT_LOWERDIR:
kfree(config->lowerdir);
config->lowerdir = match_strdup(&args[0]);
if (!config->lowerdir)
return -ENOMEM;
break;
token = match_token(opt, ovl_tokens, args);
switch (token) {
case OPT_UPPERDIR:
kfree(config->upperdir);
config->upperdir = match_strdup(&args[0]);
if (!config->upperdir)
return -ENOMEM;
break;

case OPT_LOWERDIR:
kfree(config->lowerdir);
config->lowerdir = match_strdup(&args[0]);
if (!config->lowerdir)
return -ENOMEM;
break;

case OPT_WORKDIR:
kfree(config->workdir);
config->workdir = match_strdup(&args[0]);
if (!config->workdir)
return -ENOMEM;
break;

case OPT_DEFAULT_PERMISSIONS:
config->default_permissions = true;
break;

case OPT_REDIRECT_DIR_ON:
config->redirect_mode = OVL_REDIRECT_ON;
set->redirect = true;
break;

case OPT_REDIRECT_DIR_OFF:
config->redirect_mode = ovl_redirect_always_follow ?
OVL_REDIRECT_FOLLOW :
OVL_REDIRECT_NOFOLLOW;
set->redirect = true;
break;

case OPT_REDIRECT_DIR_FOLLOW:
config->redirect_mode = OVL_REDIRECT_FOLLOW;
set->redirect = true;
break;

case OPT_REDIRECT_DIR_NOFOLLOW:
config->redirect_mode = OVL_REDIRECT_NOFOLLOW;
set->redirect = true;
break;

case OPT_WORKDIR:
kfree(config->workdir);
config->workdir = match_strdup(&args[0]);
if (!config->workdir)
return -ENOMEM;
break;
case OPT_INDEX_ON:
config->index = true;
set->index = true;
break;

case OPT_DEFAULT_PERMISSIONS:
config->default_permissions = true;
break;
case OPT_INDEX_OFF:
config->index = false;
set->index = true;
break;

case OPT_REDIRECT_DIR_ON:
config->redirect_mode = OVL_REDIRECT_ON;
redirect_opt = true;
break;
case OPT_UUID_ON:
config->uuid = true;
break;

case OPT_REDIRECT_DIR_OFF:
config->redirect_mode = ovl_redirect_always_follow ?
OVL_REDIRECT_FOLLOW :
OVL_REDIRECT_NOFOLLOW;
redirect_opt = true;
break;
case OPT_UUID_OFF:
config->uuid = false;
break;

case OPT_REDIRECT_DIR_FOLLOW:
config->redirect_mode = OVL_REDIRECT_FOLLOW;
redirect_opt = true;
break;
case OPT_NFS_EXPORT_ON:
config->nfs_export = true;
set->nfs_export = true;
break;

case OPT_REDIRECT_DIR_NOFOLLOW:
config->redirect_mode = OVL_REDIRECT_NOFOLLOW;
redirect_opt = true;
break;
case OPT_NFS_EXPORT_OFF:
config->nfs_export = false;
set->nfs_export = true;
break;

case OPT_INDEX_ON:
config->index = true;
index_opt = true;
break;
case OPT_XINO_ON:
config->xino = OVL_XINO_ON;
break;

case OPT_INDEX_OFF:
config->index = false;
index_opt = true;
break;
case OPT_XINO_OFF:
config->xino = OVL_XINO_OFF;
break;

case OPT_UUID_ON:
config->uuid = true;
break;
case OPT_XINO_AUTO:
config->xino = OVL_XINO_AUTO;
break;

case OPT_UUID_OFF:
config->uuid = false;
break;
case OPT_METACOPY_ON:
config->metacopy = true;
set->metacopy = true;
break;

case OPT_NFS_EXPORT_ON:
config->nfs_export = true;
nfs_export_opt = true;
break;

case OPT_NFS_EXPORT_OFF:
config->nfs_export = false;
nfs_export_opt = true;
break;

case OPT_XINO_ON:
config->xino = OVL_XINO_ON;
break;

case OPT_XINO_OFF:
config->xino = OVL_XINO_OFF;
break;
case OPT_METACOPY_OFF:
config->metacopy = false;
set->metacopy = true;
break;

case OPT_XINO_AUTO:
config->xino = OVL_XINO_AUTO;
break;
case OPT_VOLATILE:
config->ovl_volatile = true;
break;

case OPT_METACOPY_ON:
config->metacopy = true;
metacopy_opt = true;
break;
case OPT_USERXATTR:
config->userxattr = true;
break;

case OPT_METACOPY_OFF:
config->metacopy = false;
metacopy_opt = true;
break;
default:
pr_err("unrecognized mount option \"%s\" or missing value\n",
opt);
return -EINVAL;
}

case OPT_VOLATILE:
config->ovl_volatile = true;
break;
return err;
}

case OPT_USERXATTR:
config->userxattr = true;
break;
static int ovl_parse_options(char *opt, struct ovl_config *config)
{
char *p;
int err;
struct ovl_opt_set set = {};

default:
pr_err("unrecognized mount option \"%s\" or missing value\n",
p);
return -EINVAL;
}
while ((p = ovl_next_opt(&opt)) != NULL) {
err = ovl_parse_opt(p, config, &set);
if (err)
return err;
}

/* Workdir/index are useless in non-upper mount */
Expand All @@ -649,9 +660,9 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
kfree(config->workdir);
config->workdir = NULL;
}
if (config->index && index_opt) {
if (config->index && set.index) {
pr_info("option \"index=on\" is useless in a non-upper mount, ignore\n");
index_opt = false;
set.index = false;
}
config->index = false;
}
Expand All @@ -670,12 +681,12 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)

/* Resolve metacopy -> redirect_dir dependency */
if (config->metacopy && config->redirect_mode != OVL_REDIRECT_ON) {
if (metacopy_opt && redirect_opt) {
if (set.metacopy && set.redirect) {
pr_err("conflicting options: metacopy=on,redirect_dir=%s\n",
ovl_redirect_mode(config));
return -EINVAL;
}
if (redirect_opt) {
if (set.redirect) {
/*
* There was an explicit redirect_dir=... that resulted
* in this conflict.
Expand All @@ -695,10 +706,10 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
config->redirect_mode != OVL_REDIRECT_NOFOLLOW) {
pr_info("NFS export requires \"redirect_dir=nofollow\" on non-upper mount, falling back to nfs_export=off.\n");
config->nfs_export = false;
} else if (nfs_export_opt && index_opt) {
} else if (set.nfs_export && set.index) {
pr_err("conflicting options: nfs_export=on,index=off\n");
return -EINVAL;
} else if (index_opt) {
} else if (set.index) {
/*
* There was an explicit index=off that resulted
* in this conflict.
Expand All @@ -713,11 +724,11 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)

/* Resolve nfs_export -> !metacopy dependency */
if (config->nfs_export && config->metacopy) {
if (nfs_export_opt && metacopy_opt) {
if (set.nfs_export && set.metacopy) {
pr_err("conflicting options: nfs_export=on,metacopy=on\n");
return -EINVAL;
}
if (metacopy_opt) {
if (set.metacopy) {
/*
* There was an explicit metacopy=on that resulted
* in this conflict.
Expand All @@ -737,13 +748,13 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)

/* Resolve userxattr -> !redirect && !metacopy dependency */
if (config->userxattr) {
if (redirect_opt &&
if (set.redirect &&
config->redirect_mode != OVL_REDIRECT_NOFOLLOW) {
pr_err("conflicting options: userxattr,redirect_dir=%s\n",
ovl_redirect_mode(config));
return -EINVAL;
}
if (config->metacopy && metacopy_opt) {
if (config->metacopy && set.metacopy) {
pr_err("conflicting options: userxattr,metacopy=on\n");
return -EINVAL;
}
Expand Down Expand Up @@ -1981,7 +1992,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
ofs->config.nfs_export = ovl_nfs_export_def;
ofs->config.xino = ovl_xino_def();
ofs->config.metacopy = ovl_metacopy_def;
err = ovl_parse_opt((char *) data, &ofs->config);
err = ovl_parse_options((char *) data, &ofs->config);
if (err)
goto out_err;

Expand Down

0 comments on commit ac51962

Please sign in to comment.