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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 /drivers
parent0153431c85af3d4470ac8c59a3f854a3926dff86 (diff)
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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 'drivers')
-rw-r--r--drivers/firmware/efi/efi.c1
-rw-r--r--drivers/firmware/efi/vars.c12
2 files changed, 13 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index abeff7dc0b58..d0dfa007bffc 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -211,6 +211,7 @@ static int generic_ops_register(void)
generic_ops.get_variable = efi.get_variable;
generic_ops.get_next_variable = efi.get_next_variable;
generic_ops.query_variable_store = efi_query_variable_store;
+ generic_ops.query_variable_info = efi.query_variable_info;
if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) {
generic_ops.set_variable = efi.set_variable;
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index bfc5fa6aa47b..e9dc7116daf1 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -245,3 +245,15 @@ efi_status_t efivar_set_variable(efi_char16_t *name, efi_guid_t *vendor,
return status;
}
EXPORT_SYMBOL_NS_GPL(efivar_set_variable, EFIVAR);
+
+efi_status_t efivar_query_variable_info(u32 attr,
+ u64 *storage_space,
+ u64 *remaining_space,
+ u64 *max_variable_size)
+{
+ if (!__efivars->ops->query_variable_info)
+ return EFI_UNSUPPORTED;
+ return __efivars->ops->query_variable_info(attr, storage_space,
+ remaining_space, max_variable_size);
+}
+EXPORT_SYMBOL_NS_GPL(efivar_query_variable_info, EFIVAR);