ovl: factor out ovl_parse_options() helper

For parsing a single mount option.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 80c1022..30227cc 100644 (file)
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -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:

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 5a84af9..dbd9151 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -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 */
@@ -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;
        }
@@ -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.
@@ -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.
@@ -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.
@@ -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;
                }
@@ -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;