1 files changed, 112 insertions, 143 deletions

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index b514c67e5fc2..7a13ffb07c23 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -10,6 +10,8 @@
 #include <linux/parser.h>
 #include <linux/seq_file.h>
 #include <linux/crc32c.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include "xattr.h"
 
 #define CREATE_TRACE_POINTS
@@ -192,53 +194,18 @@ out:
 	return ret;
 }
 
-#ifdef CONFIG_EROFS_FS_ZIP
-static int erofs_build_cache_strategy(struct super_block *sb,
-				      substring_t *args)
-{
-	struct erofs_sb_info *sbi = EROFS_SB(sb);
-	const char *cs = match_strdup(args);
-	int err = 0;
-
-	if (!cs) {
-		erofs_err(sb, "Not enough memory to store cache strategy");
-		return -ENOMEM;
-	}
-
-	if (!strcmp(cs, "disabled")) {
-		sbi->cache_strategy = EROFS_ZIP_CACHE_DISABLED;
-	} else if (!strcmp(cs, "readahead")) {
-		sbi->cache_strategy = EROFS_ZIP_CACHE_READAHEAD;
-	} else if (!strcmp(cs, "readaround")) {
-		sbi->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
-	} else {
-		erofs_err(sb, "Unrecognized cache strategy \"%s\"", cs);
-		err = -EINVAL;
-	}
-	kfree(cs);
-	return err;
-}
-#else
-static int erofs_build_cache_strategy(struct super_block *sb,
-				      substring_t *args)
-{
-	erofs_info(sb, "EROFS compression is disabled, so cache strategy is ignored");
-	return 0;
-}
-#endif
-
 /* set up default EROFS parameters */
-static void erofs_default_options(struct erofs_sb_info *sbi)
+static void erofs_default_options(struct erofs_fs_context *ctx)
 {
 #ifdef CONFIG_EROFS_FS_ZIP
-	sbi->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
-	sbi->max_sync_decompress_pages = 3;
+	ctx->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
+	ctx->max_sync_decompress_pages = 3;
 #endif
 #ifdef CONFIG_EROFS_FS_XATTR
-	set_opt(sbi, XATTR_USER);
+	set_opt(ctx, XATTR_USER);
 #endif
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
-	set_opt(sbi, POSIX_ACL);
+	set_opt(ctx, POSIX_ACL);
 #endif
 }
 
@@ -251,73 +218,62 @@ enum {
 	Opt_err
 };
 
-static match_table_t erofs_tokens = {
-	{Opt_user_xattr, "user_xattr"},
-	{Opt_nouser_xattr, "nouser_xattr"},
-	{Opt_acl, "acl"},
-	{Opt_noacl, "noacl"},
-	{Opt_cache_strategy, "cache_strategy=%s"},
-	{Opt_err, NULL}
+static const struct constant_table erofs_param_cache_strategy[] = {
+	{"disabled",	EROFS_ZIP_CACHE_DISABLED},
+	{"readahead",	EROFS_ZIP_CACHE_READAHEAD},
+	{"readaround",	EROFS_ZIP_CACHE_READAROUND},
+	{}
 };
 
-static int erofs_parse_options(struct super_block *sb, char *options)
-{
-	substring_t args[MAX_OPT_ARGS];
-	char *p;
-	int err;
-
-	if (!options)
-		return 0;
-
-	while ((p = strsep(&options, ","))) {
-		int token;
+static const struct fs_parameter_spec erofs_fs_parameters[] = {
+	fsparam_flag_no("user_xattr",	Opt_user_xattr),
+	fsparam_flag_no("acl",		Opt_acl),
+	fsparam_enum("cache_strategy",	Opt_cache_strategy,
+		     erofs_param_cache_strategy),
+	{}
+};
 
-		if (!*p)
-			continue;
+static int erofs_fc_parse_param(struct fs_context *fc,
+				struct fs_parameter *param)
+{
+	struct erofs_fs_context *ctx __maybe_unused = fc->fs_private;
+	struct fs_parse_result result;
+	int opt;
 
-		args[0].to = args[0].from = NULL;
-		token = match_token(p, erofs_tokens, args);
+	opt = fs_parse(fc, erofs_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
 
-		switch (token) {
+	switch (opt) {
+	case Opt_user_xattr:
 #ifdef CONFIG_EROFS_FS_XATTR
-		case Opt_user_xattr:
-			set_opt(EROFS_SB(sb), XATTR_USER);
-			break;
-		case Opt_nouser_xattr:
-			clear_opt(EROFS_SB(sb), XATTR_USER);
-			break;
+		if (result.boolean)
+			set_opt(ctx, XATTR_USER);
+		else
+			clear_opt(ctx, XATTR_USER);
 #else
-		case Opt_user_xattr:
-			erofs_info(sb, "user_xattr options not supported");
-			break;
-		case Opt_nouser_xattr:
-			erofs_info(sb, "nouser_xattr options not supported");
-			break;
+		errorfc(fc, "{,no}user_xattr options not supported");
 #endif
+		break;
+	case Opt_acl:
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
-		case Opt_acl:
-			set_opt(EROFS_SB(sb), POSIX_ACL);
-			break;
-		case Opt_noacl:
-			clear_opt(EROFS_SB(sb), POSIX_ACL);
-			break;
+		if (result.boolean)
+			set_opt(ctx, POSIX_ACL);
+		else
+			clear_opt(ctx, POSIX_ACL);
 #else
-		case Opt_acl:
-			erofs_info(sb, "acl options not supported");
-			break;
-		case Opt_noacl:
-			erofs_info(sb, "noacl options not supported");
-			break;
+		errorfc(fc, "{,no}acl options not supported");
 #endif
-		case Opt_cache_strategy:
-			err = erofs_build_cache_strategy(sb, args);
-			if (err)
-				return err;
-			break;
-		default:
-			erofs_err(sb, "Unrecognized mount option \"%s\" or missing value", p);
-			return -EINVAL;
-		}
+		break;
+	case Opt_cache_strategy:
+#ifdef CONFIG_EROFS_FS_ZIP
+		ctx->cache_strategy = result.uint_32;
+#else
+		errorfc(fc, "compression not supported, cache_strategy ignored");
+#endif
+		break;
+	default:
+		return -ENOPARAM;
 	}
 	return 0;
 }
@@ -381,10 +337,11 @@ static int erofs_init_managed_cache(struct super_block *sb)
 static int erofs_init_managed_cache(struct super_block *sb) { return 0; }
 #endif
 
-static int erofs_fill_super(struct super_block *sb, void *data, int silent)
+static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct inode *inode;
 	struct erofs_sb_info *sbi;
+	struct erofs_fs_context *ctx = fc->fs_private;
 	int err;
 
 	sb->s_magic = EROFS_SUPER_MAGIC;
@@ -408,22 +365,15 @@ static int erofs_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_time_gran = 1;
 
 	sb->s_op = &erofs_sops;
-
-#ifdef CONFIG_EROFS_FS_XATTR
 	sb->s_xattr = erofs_xattr_handlers;
-#endif
-	/* set erofs default mount options */
-	erofs_default_options(sbi);
 
-	err = erofs_parse_options(sb, data);
-	if (err)
-		return err;
-
-	if (test_opt(sbi, POSIX_ACL))
+	if (test_opt(ctx, POSIX_ACL))
 		sb->s_flags |= SB_POSIXACL;
 	else
 		sb->s_flags &= ~SB_POSIXACL;
 
+	sbi->ctx = *ctx;
+
 #ifdef CONFIG_EROFS_FS_ZIP
 	xa_init(&sbi->managed_pslots);
 #endif
@@ -450,15 +400,58 @@ static int erofs_fill_super(struct super_block *sb, void *data, int silent)
 	if (err)
 		return err;
 
-	erofs_info(sb, "mounted with opts: %s, root inode @ nid %llu.",
-		   (char *)data, ROOT_NID(sbi));
+	erofs_info(sb, "mounted with root inode @ nid %llu.", ROOT_NID(sbi));
+	return 0;
+}
+
+static int erofs_fc_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, erofs_fc_fill_super);
+}
+
+static int erofs_fc_reconfigure(struct fs_context *fc)
+{
+	struct super_block *sb = fc->root->d_sb;
+	struct erofs_sb_info *sbi = EROFS_SB(sb);
+	struct erofs_fs_context *ctx = fc->fs_private;
+
+	DBG_BUGON(!sb_rdonly(sb));
+
+	if (test_opt(ctx, POSIX_ACL))
+		fc->sb_flags |= SB_POSIXACL;
+	else
+		fc->sb_flags &= ~SB_POSIXACL;
+
+	sbi->ctx = *ctx;
+
+	fc->sb_flags |= SB_RDONLY;
 	return 0;
 }
 
-static struct dentry *erofs_mount(struct file_system_type *fs_type, int flags,
-				  const char *dev_name, void *data)
+static void erofs_fc_free(struct fs_context *fc)
 {
-	return mount_bdev(fs_type, flags, dev_name, data, erofs_fill_super);
+	kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations erofs_context_ops = {
+	.parse_param	= erofs_fc_parse_param,
+	.get_tree       = erofs_fc_get_tree,
+	.reconfigure    = erofs_fc_reconfigure,
+	.free		= erofs_fc_free,
+};
+
+static int erofs_init_fs_context(struct fs_context *fc)
+{
+	fc->fs_private = kzalloc(sizeof(struct erofs_fs_context), GFP_KERNEL);
+	if (!fc->fs_private)
+		return -ENOMEM;
+
+	/* set default mount options */
+	erofs_default_options(fc->fs_private);
+
+	fc->ops = &erofs_context_ops;
+
+	return 0;
 }
 
 /*
@@ -497,7 +490,7 @@ static void erofs_put_super(struct super_block *sb)
 static struct file_system_type erofs_fs_type = {
 	.owner          = THIS_MODULE,
 	.name           = "erofs",
-	.mount          = erofs_mount,
+	.init_fs_context = erofs_init_fs_context,
 	.kill_sb        = erofs_kill_sb,
 	.fs_flags       = FS_REQUIRES_DEV,
 };
@@ -578,61 +571,37 @@ static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
 static int erofs_show_options(struct seq_file *seq, struct dentry *root)
 {
 	struct erofs_sb_info *sbi __maybe_unused = EROFS_SB(root->d_sb);
+	struct erofs_fs_context *ctx __maybe_unused = &sbi->ctx;
 
 #ifdef CONFIG_EROFS_FS_XATTR
-	if (test_opt(sbi, XATTR_USER))
+	if (test_opt(ctx, XATTR_USER))
 		seq_puts(seq, ",user_xattr");
 	else
 		seq_puts(seq, ",nouser_xattr");
 #endif
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
-	if (test_opt(sbi, POSIX_ACL))
+	if (test_opt(ctx, POSIX_ACL))
 		seq_puts(seq, ",acl");
 	else
 		seq_puts(seq, ",noacl");
 #endif
 #ifdef CONFIG_EROFS_FS_ZIP
-	if (sbi->cache_strategy == EROFS_ZIP_CACHE_DISABLED) {
+	if (ctx->cache_strategy == EROFS_ZIP_CACHE_DISABLED)
 		seq_puts(seq, ",cache_strategy=disabled");
-	} else if (sbi->cache_strategy == EROFS_ZIP_CACHE_READAHEAD) {
+	else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAHEAD)
 		seq_puts(seq, ",cache_strategy=readahead");
-	} else if (sbi->cache_strategy == EROFS_ZIP_CACHE_READAROUND) {
+	else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAROUND)
 		seq_puts(seq, ",cache_strategy=readaround");
-	}
 #endif
 	return 0;
 }
 
-static int erofs_remount(struct super_block *sb, int *flags, char *data)
-{
-	struct erofs_sb_info *sbi = EROFS_SB(sb);
-	unsigned int org_mnt_opt = sbi->mount_opt;
-	int err;
-
-	DBG_BUGON(!sb_rdonly(sb));
-	err = erofs_parse_options(sb, data);
-	if (err)
-		goto out;
-
-	if (test_opt(sbi, POSIX_ACL))
-		sb->s_flags |= SB_POSIXACL;
-	else
-		sb->s_flags &= ~SB_POSIXACL;
-
-	*flags |= SB_RDONLY;
-	return 0;
-out:
-	sbi->mount_opt = org_mnt_opt;
-	return err;
-}
-
 const struct super_operations erofs_sops = {
 	.put_super = erofs_put_super,
 	.alloc_inode = erofs_alloc_inode,
 	.free_inode = erofs_free_inode,
 	.statfs = erofs_statfs,
 	.show_options = erofs_show_options,
-	.remount_fs = erofs_remount,
 };
 
 module_init(erofs_module_init);