4 files changed, 85 insertions, 2 deletions

diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index 59b52718a3..7e99616398 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -51,7 +51,7 @@ static ssize_t efivarfs_file_write(struct file *file,
 	} else {
 		inode_lock(inode);
 		i_size_write(inode, datasize + sizeof(attributes));
-		inode->i_mtime = inode_set_ctime_current(inode);
+		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
 		inode_unlock(inode);
 	}
 
diff --git a/fs/efivarfs/inode.c b/fs/efivarfs/inode.c
index db9231f0e7..91290fe4a7 100644
--- a/fs/efivarfs/inode.c
+++ b/fs/efivarfs/inode.c
@@ -21,11 +21,15 @@ struct inode *efivarfs_get_inode(struct super_block *sb,
 				dev_t dev, bool is_removable)
 {
 	struct inode *inode = new_inode(sb);
+	struct efivarfs_fs_info *fsi = sb->s_fs_info;
+	struct efivarfs_mount_opts *opts = &fsi->mount_opts;
 
 	if (inode) {
+		inode->i_uid = opts->uid;
+		inode->i_gid = opts->gid;
 		inode->i_ino = get_next_ino();
 		inode->i_mode = mode;
-		inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode);
+		simple_inode_init_ts(inode);
 		inode->i_flags = is_removable ? 0 : S_IMMUTABLE;
 		switch (mode & S_IFMT) {
 		case S_IFREG:
diff --git a/fs/efivarfs/internal.h b/fs/efivarfs/internal.h
index 8ebf3a6a8a..c66647f5c0 100644
--- a/fs/efivarfs/internal.h
+++ b/fs/efivarfs/internal.h
@@ -9,6 +9,15 @@
 #include <linux/list.h>
 #include <linux/efi.h>
 
+struct efivarfs_mount_opts {
+	kuid_t uid;
+	kgid_t gid;
+};
+
+struct efivarfs_fs_info {
+	struct efivarfs_mount_opts mount_opts;
+};
+
 struct efi_variable {
 	efi_char16_t  VariableName[EFI_VAR_NAME_LEN/sizeof(efi_char16_t)];
 	efi_guid_t    VendorGuid;
diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index d59d967096..edf29c15db 100644
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -8,6 +8,7 @@
 #include <linux/efi.h>
 #include <linux/fs.h>
 #include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include <linux/module.h>
 #include <linux/pagemap.h>
 #include <linux/ucs2_string.h>
@@ -25,12 +26,28 @@ static void efivarfs_evict_inode(struct inode *inode)
 	clear_inode(inode);
 }
 
+static int efivarfs_show_options(struct seq_file *m, struct dentry *root)
+{
+	struct super_block *sb = root->d_sb;
+	struct efivarfs_fs_info *sbi = sb->s_fs_info;
+	struct efivarfs_mount_opts *opts = &sbi->mount_opts;
+
+	if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
+		seq_printf(m, ",uid=%u",
+				from_kuid_munged(&init_user_ns, opts->uid));
+	if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
+		seq_printf(m, ",gid=%u",
+				from_kgid_munged(&init_user_ns, opts->gid));
+	return 0;
+}
+
 static int efivarfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	const u32 attr = EFI_VARIABLE_NON_VOLATILE |
 			 EFI_VARIABLE_BOOTSERVICE_ACCESS |
 			 EFI_VARIABLE_RUNTIME_ACCESS;
 	u64 storage_space, remaining_space, max_variable_size;
+	u64 id = huge_encode_dev(dentry->d_sb->s_dev);
 	efi_status_t status;
 
 	/* Some UEFI firmware does not implement QueryVariableInfo() */
@@ -54,6 +71,7 @@ static int efivarfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_blocks	= storage_space;
 	buf->f_bfree	= remaining_space;
 	buf->f_type	= dentry->d_sb->s_magic;
+	buf->f_fsid	= u64_to_fsid(id);
 
 	/*
 	 * In f_bavail we declare the free space that the kernel will allow writing
@@ -71,6 +89,7 @@ static const struct super_operations efivarfs_ops = {
 	.statfs = efivarfs_statfs,
 	.drop_inode = generic_delete_inode,
 	.evict_inode = efivarfs_evict_inode,
+	.show_options = efivarfs_show_options,
 };
 
 /*
@@ -232,6 +251,45 @@ static int efivarfs_destroy(struct efivar_entry *entry, void *data)
 	return 0;
 }
 
+enum {
+	Opt_uid, Opt_gid,
+};
+
+static const struct fs_parameter_spec efivarfs_parameters[] = {
+	fsparam_u32("uid", Opt_uid),
+	fsparam_u32("gid", Opt_gid),
+	{},
+};
+
+static int efivarfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct efivarfs_fs_info *sbi = fc->s_fs_info;
+	struct efivarfs_mount_opts *opts = &sbi->mount_opts;
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, efivarfs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_uid:
+		opts->uid = make_kuid(current_user_ns(), result.uint_32);
+		if (!uid_valid(opts->uid))
+			return -EINVAL;
+		break;
+	case Opt_gid:
+		opts->gid = make_kgid(current_user_ns(), result.uint_32);
+		if (!gid_valid(opts->gid))
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int efivarfs_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct inode *inode = NULL;
@@ -288,11 +346,22 @@ static int efivarfs_reconfigure(struct fs_context *fc)
 
 static const struct fs_context_operations efivarfs_context_ops = {
 	.get_tree	= efivarfs_get_tree,
+	.parse_param	= efivarfs_parse_param,
 	.reconfigure	= efivarfs_reconfigure,
 };
 
 static int efivarfs_init_fs_context(struct fs_context *fc)
 {
+	struct efivarfs_fs_info *sfi;
+
+	sfi = kzalloc(sizeof(*sfi), GFP_KERNEL);
+	if (!sfi)
+		return -ENOMEM;
+
+	sfi->mount_opts.uid = GLOBAL_ROOT_UID;
+	sfi->mount_opts.gid = GLOBAL_ROOT_GID;
+
+	fc->s_fs_info = sfi;
 	fc->ops = &efivarfs_context_ops;
 	return 0;
 }
@@ -316,6 +385,7 @@ static struct file_system_type efivarfs_type = {
 	.name    = "efivarfs",
 	.init_fs_context = efivarfs_init_fs_context,
 	.kill_sb = efivarfs_kill_sb,
+	.parameters = efivarfs_parameters,
 };
 
 static __init int efivarfs_init(void)