Merge tag 'vfs-6.13.ecryptfs.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull ecryptfs mount api conversion from Christian Brauner:
 "Convert ecryptfs to the new mount api"

* tag 'vfs-6.13.ecryptfs.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  ecryptfs: Fix spelling mistake "validationg" -> "validating"
  ecryptfs: Convert ecryptfs to use the new mount API
  ecryptfs: Factor out mount option validation

1 files changed, 205 insertions, 196 deletions

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 577c56302314..8dd1d7189c3b 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -15,10 +15,10 @@
 #include <linux/module.h>
 #include <linux/namei.h>
 #include <linux/skbuff.h>
-#include <linux/mount.h>
 #include <linux/pagemap.h>
 #include <linux/key.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include <linux/fs_stack.h>
 #include <linux/slab.h>
 #include <linux/magic.h>
@@ -153,32 +153,30 @@ void ecryptfs_put_lower_file(struct inode *inode)
 	}
 }
 
-enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
-       ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
-       ecryptfs_opt_ecryptfs_key_bytes,
-       ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
-       ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
-       ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
-       ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only,
-       ecryptfs_opt_check_dev_ruid,
-       ecryptfs_opt_err };
-
-static const match_table_t tokens = {
-	{ecryptfs_opt_sig, "sig=%s"},
-	{ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
-	{ecryptfs_opt_cipher, "cipher=%s"},
-	{ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
-	{ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
-	{ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
-	{ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
-	{ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
-	{ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"},
-	{ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
-	{ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
-	{ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
-	{ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
-	{ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"},
-	{ecryptfs_opt_err, NULL}
+enum {
+	Opt_sig, Opt_ecryptfs_sig, Opt_cipher, Opt_ecryptfs_cipher,
+	Opt_ecryptfs_key_bytes, Opt_passthrough, Opt_xattr_metadata,
+	Opt_encrypted_view, Opt_fnek_sig, Opt_fn_cipher,
+	Opt_fn_cipher_key_bytes, Opt_unlink_sigs, Opt_mount_auth_tok_only,
+	Opt_check_dev_ruid
+};
+
+static const struct fs_parameter_spec ecryptfs_fs_param_spec[] = {
+	fsparam_string	("sig",			    Opt_sig),
+	fsparam_string	("ecryptfs_sig",	    Opt_ecryptfs_sig),
+	fsparam_string	("cipher",		    Opt_cipher),
+	fsparam_string	("ecryptfs_cipher",	    Opt_ecryptfs_cipher),
+	fsparam_u32	("ecryptfs_key_bytes",	    Opt_ecryptfs_key_bytes),
+	fsparam_flag	("ecryptfs_passthrough",    Opt_passthrough),
+	fsparam_flag	("ecryptfs_xattr_metadata", Opt_xattr_metadata),
+	fsparam_flag	("ecryptfs_encrypted_view", Opt_encrypted_view),
+	fsparam_string	("ecryptfs_fnek_sig",	    Opt_fnek_sig),
+	fsparam_string	("ecryptfs_fn_cipher",	    Opt_fn_cipher),
+	fsparam_u32	("ecryptfs_fn_key_bytes",   Opt_fn_cipher_key_bytes),
+	fsparam_flag	("ecryptfs_unlink_sigs",    Opt_unlink_sigs),
+	fsparam_flag	("ecryptfs_mount_auth_tok_only", Opt_mount_auth_tok_only),
+	fsparam_flag	("ecryptfs_check_dev_ruid", Opt_check_dev_ruid),
+	{}
 };
 
 static int ecryptfs_init_global_auth_toks(
@@ -219,19 +217,20 @@ static void ecryptfs_init_mount_crypt_stat(
 	mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
 }
 
+struct ecryptfs_fs_context {
+	/* Mount option status trackers */
+	bool check_ruid;
+	bool sig_set;
+	bool cipher_name_set;
+	bool cipher_key_bytes_set;
+	bool fn_cipher_name_set;
+	bool fn_cipher_key_bytes_set;
+};
+
 /**
- * ecryptfs_parse_options
- * @sbi: The ecryptfs super block
- * @options: The options passed to the kernel
- * @check_ruid: set to 1 if device uid should be checked against the ruid
- *
- * Parse mount options:
- * debug=N 	   - ecryptfs_verbosity level for debug output
- * sig=XXX	   - description(signature) of the key to use
- *
- * Returns the dentry object of the lower-level (lower/interposed)
- * directory; We want to mount our stackable file system on top of
- * that lower directory.
+ * ecryptfs_parse_param
+ * @fc: The ecryptfs filesystem context
+ * @param: The mount parameter to parse
  *
  * The signature of the key to use must be the description of a key
  * already in the keyring. Mounting will fail if the key can not be
@@ -239,143 +238,118 @@ static void ecryptfs_init_mount_crypt_stat(
  *
  * Returns zero on success; non-zero on error
  */
-static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
-				  uid_t *check_ruid)
+static int ecryptfs_parse_param(
+	struct fs_context *fc,
+	struct fs_parameter *param)
 {
-	char *p;
-	int rc = 0;
-	int sig_set = 0;
-	int cipher_name_set = 0;
-	int fn_cipher_name_set = 0;
-	int cipher_key_bytes;
-	int cipher_key_bytes_set = 0;
-	int fn_cipher_key_bytes;
-	int fn_cipher_key_bytes_set = 0;
+	int rc;
+	int opt;
+	struct fs_parse_result result;
+	struct ecryptfs_fs_context *ctx = fc->fs_private;
+	struct ecryptfs_sb_info *sbi = fc->s_fs_info;
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 		&sbi->mount_crypt_stat;
-	substring_t args[MAX_OPT_ARGS];
-	int token;
-	char *sig_src;
-	char *cipher_name_src;
-	char *fn_cipher_name_src;
-	char *fnek_src;
-	char *cipher_key_bytes_src;
-	char *fn_cipher_key_bytes_src;
-	u8 cipher_code;
 
-	*check_ruid = 0;
+	opt = fs_parse(fc, ecryptfs_fs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
 
-	if (!options) {
-		rc = -EINVAL;
-		goto out;
-	}
-	ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
-	while ((p = strsep(&options, ",")) != NULL) {
-		if (!*p)
-			continue;
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case ecryptfs_opt_sig:
-		case ecryptfs_opt_ecryptfs_sig:
-			sig_src = args[0].from;
-			rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
-							  sig_src, 0);
-			if (rc) {
-				printk(KERN_ERR "Error attempting to register "
-				       "global sig; rc = [%d]\n", rc);
-				goto out;
-			}
-			sig_set = 1;
-			break;
-		case ecryptfs_opt_cipher:
-		case ecryptfs_opt_ecryptfs_cipher:
-			cipher_name_src = args[0].from;
-			strscpy(mount_crypt_stat->global_default_cipher_name,
-				cipher_name_src);
-			cipher_name_set = 1;
-			break;
-		case ecryptfs_opt_ecryptfs_key_bytes:
-			cipher_key_bytes_src = args[0].from;
-			cipher_key_bytes =
-				(int)simple_strtol(cipher_key_bytes_src,
-						   &cipher_key_bytes_src, 0);
-			mount_crypt_stat->global_default_cipher_key_size =
-				cipher_key_bytes;
-			cipher_key_bytes_set = 1;
-			break;
-		case ecryptfs_opt_passthrough:
-			mount_crypt_stat->flags |=
-				ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
-			break;
-		case ecryptfs_opt_xattr_metadata:
-			mount_crypt_stat->flags |=
-				ECRYPTFS_XATTR_METADATA_ENABLED;
-			break;
-		case ecryptfs_opt_encrypted_view:
-			mount_crypt_stat->flags |=
-				ECRYPTFS_XATTR_METADATA_ENABLED;
-			mount_crypt_stat->flags |=
-				ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
-			break;
-		case ecryptfs_opt_fnek_sig:
-			fnek_src = args[0].from;
-			strscpy(mount_crypt_stat->global_default_fnek_sig,
-				fnek_src);
-			rc = ecryptfs_add_global_auth_tok(
-				mount_crypt_stat,
-				mount_crypt_stat->global_default_fnek_sig,
-				ECRYPTFS_AUTH_TOK_FNEK);
-			if (rc) {
-				printk(KERN_ERR "Error attempting to register "
-				       "global fnek sig [%s]; rc = [%d]\n",
-				       mount_crypt_stat->global_default_fnek_sig,
-				       rc);
-				goto out;
-			}
-			mount_crypt_stat->flags |=
-				(ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
-				 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
-			break;
-		case ecryptfs_opt_fn_cipher:
-			fn_cipher_name_src = args[0].from;
-			strscpy(mount_crypt_stat->global_default_fn_cipher_name,
-				fn_cipher_name_src);
-			fn_cipher_name_set = 1;
-			break;
-		case ecryptfs_opt_fn_cipher_key_bytes:
-			fn_cipher_key_bytes_src = args[0].from;
-			fn_cipher_key_bytes =
-				(int)simple_strtol(fn_cipher_key_bytes_src,
-						   &fn_cipher_key_bytes_src, 0);
-			mount_crypt_stat->global_default_fn_cipher_key_bytes =
-				fn_cipher_key_bytes;
-			fn_cipher_key_bytes_set = 1;
-			break;
-		case ecryptfs_opt_unlink_sigs:
-			mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
-			break;
-		case ecryptfs_opt_mount_auth_tok_only:
-			mount_crypt_stat->flags |=
-				ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
-			break;
-		case ecryptfs_opt_check_dev_ruid:
-			*check_ruid = 1;
-			break;
-		case ecryptfs_opt_err:
-		default:
-			printk(KERN_WARNING
-			       "%s: eCryptfs: unrecognized option [%s]\n",
-			       __func__, p);
+	switch (opt) {
+	case Opt_sig:
+	case Opt_ecryptfs_sig:
+		rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
+						  param->string, 0);
+		if (rc) {
+			printk(KERN_ERR "Error attempting to register "
+			       "global sig; rc = [%d]\n", rc);
+			return rc;
+		}
+		ctx->sig_set = 1;
+		break;
+	case Opt_cipher:
+	case Opt_ecryptfs_cipher:
+		strscpy(mount_crypt_stat->global_default_cipher_name,
+			param->string);
+		ctx->cipher_name_set = 1;
+		break;
+	case Opt_ecryptfs_key_bytes:
+		mount_crypt_stat->global_default_cipher_key_size =
+			result.uint_32;
+		ctx->cipher_key_bytes_set = 1;
+		break;
+	case Opt_passthrough:
+		mount_crypt_stat->flags |=
+			ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
+		break;
+	case Opt_xattr_metadata:
+		mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED;
+		break;
+	case Opt_encrypted_view:
+		mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED;
+		mount_crypt_stat->flags |= ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
+		break;
+	case Opt_fnek_sig:
+		strscpy(mount_crypt_stat->global_default_fnek_sig,
+			param->string);
+		rc = ecryptfs_add_global_auth_tok(
+			mount_crypt_stat,
+			mount_crypt_stat->global_default_fnek_sig,
+			ECRYPTFS_AUTH_TOK_FNEK);
+		if (rc) {
+			printk(KERN_ERR "Error attempting to register "
+			       "global fnek sig [%s]; rc = [%d]\n",
+			       mount_crypt_stat->global_default_fnek_sig, rc);
+			return rc;
 		}
+		mount_crypt_stat->flags |=
+			(ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
+			 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
+		break;
+	case Opt_fn_cipher:
+		strscpy(mount_crypt_stat->global_default_fn_cipher_name,
+			param->string);
+		ctx->fn_cipher_name_set = 1;
+		break;
+	case Opt_fn_cipher_key_bytes:
+		mount_crypt_stat->global_default_fn_cipher_key_bytes =
+			result.uint_32;
+		ctx->fn_cipher_key_bytes_set = 1;
+		break;
+	case Opt_unlink_sigs:
+		mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
+		break;
+	case Opt_mount_auth_tok_only:
+		mount_crypt_stat->flags |= ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
+		break;
+	case Opt_check_dev_ruid:
+		ctx->check_ruid = 1;
+		break;
+	default:
+		return -EINVAL;
 	}
-	if (!sig_set) {
+
+	return 0;
+}
+
+static int ecryptfs_validate_options(struct fs_context *fc)
+{
+	int rc = 0;
+	u8 cipher_code;
+	struct ecryptfs_fs_context *ctx = fc->fs_private;
+	struct ecryptfs_sb_info *sbi = fc->s_fs_info;
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+
+
+	mount_crypt_stat = &sbi->mount_crypt_stat;
+
+	if (!ctx->sig_set) {
 		rc = -EINVAL;
 		ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
 				"auth tok signature as a mount "
 				"parameter; see the eCryptfs README\n");
 		goto out;
 	}
-	if (!cipher_name_set) {
+	if (!ctx->cipher_name_set) {
 		int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
 
 		BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE);
@@ -383,13 +357,13 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 		       ECRYPTFS_DEFAULT_CIPHER);
 	}
 	if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
-	    && !fn_cipher_name_set)
+	    && !ctx->fn_cipher_name_set)
 		strcpy(mount_crypt_stat->global_default_fn_cipher_name,
 		       mount_crypt_stat->global_default_cipher_name);
-	if (!cipher_key_bytes_set)
+	if (!ctx->cipher_key_bytes_set)
 		mount_crypt_stat->global_default_cipher_key_size = 0;
 	if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
-	    && !fn_cipher_key_bytes_set)
+	    && !ctx->fn_cipher_key_bytes_set)
 		mount_crypt_stat->global_default_fn_cipher_key_bytes =
 			mount_crypt_stat->global_default_cipher_key_size;
 
@@ -453,45 +427,35 @@ struct kmem_cache *ecryptfs_sb_info_cache;
 static struct file_system_type ecryptfs_fs_type;
 
 /*
- * ecryptfs_mount
- * @fs_type: The filesystem type that the superblock should belong to
- * @flags: The flags associated with the mount
- * @dev_name: The path to mount over
- * @raw_data: The options passed into the kernel
+ * ecryptfs_get_tree
+ * @fc: The filesystem context
  */
-static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
-			const char *dev_name, void *raw_data)
+static int ecryptfs_get_tree(struct fs_context *fc)
 {
 	struct super_block *s;
-	struct ecryptfs_sb_info *sbi;
+	struct ecryptfs_fs_context *ctx = fc->fs_private;
+	struct ecryptfs_sb_info *sbi = fc->s_fs_info;
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
 	struct ecryptfs_dentry_info *root_info;
 	const char *err = "Getting sb failed";
 	struct inode *inode;
 	struct path path;
-	uid_t check_ruid;
 	int rc;
 
-	sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
-	if (!sbi) {
-		rc = -ENOMEM;
-		goto out;
-	}
-
-	if (!dev_name) {
+	if (!fc->source) {
 		rc = -EINVAL;
 		err = "Device name cannot be null";
 		goto out;
 	}
 
-	rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid);
+	mount_crypt_stat = &sbi->mount_crypt_stat;
+	rc = ecryptfs_validate_options(fc);
 	if (rc) {
-		err = "Error parsing options";
+		err = "Error validating options";
 		goto out;
 	}
-	mount_crypt_stat = &sbi->mount_crypt_stat;
 
-	s = sget(fs_type, NULL, set_anon_super, flags, NULL);
+	s = sget_fc(fc, NULL, set_anon_super_fc);
 	if (IS_ERR(s)) {
 		rc = PTR_ERR(s);
 		goto out;
@@ -510,7 +474,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
 	s->s_d_op = &ecryptfs_dops;
 
 	err = "Reading sb failed";
-	rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
+	rc = kern_path(fc->source, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
 	if (rc) {
 		ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
 		goto out1;
@@ -529,7 +493,8 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
 		goto out_free;
 	}
 
-	if (check_ruid && !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) {
+	if (ctx->check_ruid &&
+	    !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) {
 		rc = -EPERM;
 		printk(KERN_ERR "Mount of device (uid: %d) not owned by "
 		       "requested user (uid: %d)\n",
@@ -544,7 +509,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
 	 * Set the POSIX ACL flag based on whether they're enabled in the lower
 	 * mount.
 	 */
-	s->s_flags = flags & ~SB_POSIXACL;
+	s->s_flags = fc->sb_flags & ~SB_POSIXACL;
 	s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL;
 
 	/**
@@ -587,19 +552,19 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
 	root_info->lower_path = path;
 
 	s->s_flags |= SB_ACTIVE;
-	return dget(s->s_root);
+	fc->root = dget(s->s_root);
+	return 0;
 
 out_free:
 	path_put(&path);
 out1:
 	deactivate_locked_super(s);
 out:
-	if (sbi) {
+	if (sbi)
 		ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
-		kmem_cache_free(ecryptfs_sb_info_cache, sbi);
-	}
+
 	printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
-	return ERR_PTR(rc);
+	return rc;
 }
 
 /**
@@ -618,10 +583,54 @@ static void ecryptfs_kill_block_super(struct super_block *sb)
 	kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
 }
 
+static void ecryptfs_free_fc(struct fs_context *fc)
+{
+	struct ecryptfs_fs_context *ctx = fc->fs_private;
+	struct ecryptfs_sb_info *sbi = fc->s_fs_info;
+
+	kfree(ctx);
+
+	if (sbi) {
+		ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
+		kmem_cache_free(ecryptfs_sb_info_cache, sbi);
+	}
+}
+
+static const struct fs_context_operations ecryptfs_context_ops = {
+	.free		= ecryptfs_free_fc,
+	.parse_param	= ecryptfs_parse_param,
+	.get_tree	= ecryptfs_get_tree,
+	.reconfigure	= NULL,
+};
+
+static int ecryptfs_init_fs_context(struct fs_context *fc)
+{
+	struct ecryptfs_fs_context *ctx;
+	struct ecryptfs_sb_info *sbi = NULL;
+
+	ctx = kzalloc(sizeof(struct ecryptfs_fs_context), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+	sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
+	if (!sbi) {
+		kfree(ctx);
+		ctx = NULL;
+		return -ENOMEM;
+	}
+
+	ecryptfs_init_mount_crypt_stat(&sbi->mount_crypt_stat);
+
+	fc->fs_private = ctx;
+	fc->s_fs_info = sbi;
+	fc->ops = &ecryptfs_context_ops;
+	return 0;
+}
+
 static struct file_system_type ecryptfs_fs_type = {
 	.owner = THIS_MODULE,
 	.name = "ecryptfs",
-	.mount = ecryptfs_mount,
+	.init_fs_context = ecryptfs_init_fs_context,
+	.parameters = ecryptfs_fs_param_spec,
 	.kill_sb = ecryptfs_kill_block_super,
 	.fs_flags = 0
 };