Commit 79b83606 authored by Heinrich Schuchardt's avatar Heinrich Schuchardt Committed by Ard Biesheuvel
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efivarfs: fix statfs() on efivarfs 

Some firmware (notably U-Boot) provides GetVariable() and
GetNextVariableName() but not QueryVariableInfo().

With commit d86ff333 ("efivarfs: expose used and total size") the
statfs syscall was broken for such firmware.

If QueryVariableInfo() does not exist or returns EFI_UNSUPPORTED, just
report the file system size as 0 as statfs_simple() previously did.

Fixes: d86ff333 ("efivarfs: expose used and total size")
Link: https://lore.kernel.org/all/20230910045445.41632-1-heinrich.schuchardt@canonical.com/


Signed-off-by: default avatarHeinrich Schuchardt <heinrich.schuchardt@canonical.com>
[ardb: log warning on QueryVariableInfo() failure]
Reviewed-by: default avatarIlias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent e7761d82

fs/efivarfs/super.c

+10 −4
Original line number Diff line number Diff line
@@ -32,10 +32,16 @@ static int efivarfs_statfs(struct dentry *dentry, struct kstatfs *buf) 
	u64 storage_space, remaining_space, max_variable_size;

	efi_status_t status;



	status = efivar_query_variable_info(attr, &storage_space, &remaining_space,

	/* Some UEFI firmware does not implement QueryVariableInfo() */

	storage_space = remaining_space = 0;

	if (efi_rt_services_supported(EFI_RT_SUPPORTED_QUERY_VARIABLE_INFO)) {

		status = efivar_query_variable_info(attr, &storage_space,

						    &remaining_space,

						    &max_variable_size);

	if (status != EFI_SUCCESS)

		return efi_status_to_err(status);

		if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED)

			pr_warn_ratelimited("query_variable_info() failed: 0x%lx\n",

					    status);

	}



	/*

	 * This is not a normal filesystem, so no point in pretending it has a block