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authorAnisse Astier <an.astier@criteo.com>2023-05-17 17:38:12 +0200
committerArd Biesheuvel <ardb@kernel.org>2023-05-17 18:21:34 +0200
commitd86ff3333cb1d5f42d8898fb5fdb304e143c0237 (patch)
treeb2ff1411537adc4dd46d5a69207dafc79f3de994 /arch/x86
parentefi: make kobj_type structure constant (diff)
downloadlinux-d86ff3333cb1d5f42d8898fb5fdb304e143c0237.tar.xz
linux-d86ff3333cb1d5f42d8898fb5fdb304e143c0237.zip
efivarfs: expose used and total size
When writing EFI variables, one might get errors with no other message on why it fails. Being able to see how much is used by EFI variables helps analyzing such issues. Since this is not a conventional filesystem, block size is intentionally set to 1 instead of PAGE_SIZE. x86 quirks of reserved size are taken into account; so that available and free size can be different, further helping debugging space issues. With this patch, one can see the remaining space in EFI variable storage via efivarfs, like this: $ df -h /sys/firmware/efi/efivars/ Filesystem Size Used Avail Use% Mounted on efivarfs 176K 106K 66K 62% /sys/firmware/efi/efivars Signed-off-by: Anisse Astier <an.astier@criteo.com> [ardb: - rename efi_reserved_space() to efivar_reserved_space() - whitespace/coding style tweaks] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/platform/efi/quirks.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index b0b848d6933a..f0cc00032751 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -114,6 +114,14 @@ void efi_delete_dummy_variable(void)
EFI_VARIABLE_RUNTIME_ACCESS, 0, NULL);
}
+u64 efivar_reserved_space(void)
+{
+ if (efi_no_storage_paranoia)
+ return 0;
+ return EFI_MIN_RESERVE;
+}
+EXPORT_SYMBOL_GPL(efivar_reserved_space);
+
/*
* In the nonblocking case we do not attempt to perform garbage
* collection if we do not have enough free space. Rather, we do the