@@ -114,6 +114,14 @@ void efi_delete_dummy_variable(void)
EFI_VARIABLE_RUNTIME_ACCESS, 0, NULL);
}
+u64 efi_reserved_space(void)
+{
+ if (efi_no_storage_paranoia)
+ return 0;
+ return EFI_MIN_RESERVE;
+}
+EXPORT_SYMBOL_GPL(efi_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
@@ -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;
@@ -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);
@@ -13,6 +13,7 @@
#include <linux/ucs2_string.h>
#include <linux/slab.h>
#include <linux/magic.h>
+#include <linux/statfs.h>
#include "internal.h"
@@ -23,8 +24,41 @@ static void efivarfs_evict_inode(struct inode *inode)
clear_inode(inode);
}
+static int efivarfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ u64 storage_space, remaining_space, max_variable_size;
+ efi_status_t status;
+ const u32 attr = (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS);
+
+ buf->f_type = dentry->d_sb->s_magic;
+ /*
+ * This is not a normal filesystem, so no point in pretending it has a block
+ * size; we declare f_bsize to 1, so that we can then report the exact value
+ * sent by EFI QueryVariableInfo in f_blocks and f_bfree
+ */
+ buf->f_bsize = 1;
+ buf->f_namelen = NAME_MAX;
+
+ status = efivar_query_variable_info(attr, &storage_space, &remaining_space,
+ &max_variable_size);
+ if (status != EFI_SUCCESS)
+ return efi_status_to_err(status);
+ buf->f_blocks = storage_space;
+ buf->f_bfree = remaining_space;
+ /*
+ * In f_bavail we declare the free space that the kernel will allow writing
+ * when the storage_paranoia x86 quirk is active. To use more, users
+ * should boot the kernel with efi_no_storage_paranoia.
+ */
+ if (remaining_space > efi_reserved_space())
+ buf->f_bavail = remaining_space - efi_reserved_space();
+ else
+ buf->f_bavail = 0;
+ return 0;
+}
static const struct super_operations efivarfs_ops = {
- .statfs = simple_statfs,
+ .statfs = efivarfs_statfs,
.drop_inode = generic_delete_inode,
.evict_inode = efivarfs_evict_inode,
};
@@ -703,6 +703,7 @@ static inline void efi_enter_virtual_mode (void) {}
extern efi_status_t efi_query_variable_store(u32 attributes,
unsigned long size,
bool nonblocking);
+extern u64 efi_reserved_space(void);
#else
static inline efi_status_t efi_query_variable_store(u32 attributes,
@@ -711,6 +712,10 @@ static inline efi_status_t efi_query_variable_store(u32 attributes,
{
return EFI_SUCCESS;
}
+static inline u64 efi_reserved_space(void)
+{
+ return 0;
+}
#endif
extern void __iomem *efi_lookup_mapped_addr(u64 phys_addr);
@@ -1042,6 +1047,7 @@ struct efivar_operations {
efi_set_variable_t *set_variable;
efi_set_variable_t *set_variable_nonblocking;
efi_query_variable_store_t *query_variable_store;
+ efi_query_variable_info_t *query_variable_info;
};
struct efivars {
@@ -1087,6 +1093,10 @@ efi_status_t efivar_set_variable_locked(efi_char16_t *name, efi_guid_t *vendor,
efi_status_t efivar_set_variable(efi_char16_t *name, efi_guid_t *vendor,
u32 attr, unsigned long data_size, void *data);
+efi_status_t efivar_query_variable_info(u32 attr, u64 *storage_space,
+ u64 *remaining_space,
+ u64 *max_variable_size);
+
#if IS_ENABLED(CONFIG_EFI_CAPSULE_LOADER)
extern bool efi_capsule_pending(int *reset_type);