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From:   Johan Hovold <johan+linaro@kernel.org>
To:     Ard Biesheuvel <ardb@kernel.org>
Cc:     Matthew Garrett <mjg59@srcf.ucam.org>, Jeremy Kerr <jk@ozlabs.org>,
        Maximilian Luz <luzmaximilian@gmail.com>,
        linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
        Johan Hovold <johan+linaro@kernel.org>
Subject: [PATCH 2/4] efivarfs: always register filesystem
Date:   Thu, 19 Jan 2023 17:42:53 +0100
Message-Id: <20230119164255.28091-3-johan+linaro@kernel.org>
In-Reply-To: <20230119164255.28091-1-johan+linaro@kernel.org>
References: <20230119164255.28091-1-johan+linaro@kernel.org>
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The efivar ops are typically registered at subsys init time so that
they are available when efivarfs is registered at module init time.

Other efivars implementations, such as Google SMI, exists and can
currently be build as modules which means that efivar may not be
available when efivarfs is initialised.

Move the efivar availability check from module init to when the
filesystem is mounted to allow late registration of efivars.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 fs/efivarfs/super.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index f72c529c8ec3..b67d431c861a 100644
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -194,6 +194,9 @@ static int efivarfs_fill_super(struct super_block *sb, struct fs_context *fc)
 	struct dentry *root;
 	int err;
 
+	if (!efivar_is_available())
+		return -EOPNOTSUPP;
+
 	sb->s_maxbytes          = MAX_LFS_FILESIZE;
 	sb->s_blocksize         = PAGE_SIZE;
 	sb->s_blocksize_bits    = PAGE_SHIFT;
@@ -256,9 +259,6 @@ static struct file_system_type efivarfs_type = {
 
 static __init int efivarfs_init(void)
 {
-	if (!efivar_is_available())
-		return -ENODEV;
-
 	return register_filesystem(&efivarfs_type);
 }
 
-- 
2.38.2