Commit 7e365c7e authored by James Bottomley's avatar James Bottomley Committed by Ard Biesheuvel
Browse files

efivarfs: make variable_is_present use dcache lookup 



Instead of searching the variable entry list for a variable, use the
dcache lookup functions to find it instead.  Also add an efivarfs_
prefix to the function now it is no longer static.

Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 1aba87f9

fs/efivarfs/internal.h

+2 −0
Original line number Diff line number Diff line
@@ -56,6 +56,8 @@ bool efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data, 
bool efivar_variable_is_removable(efi_guid_t vendor, const char *name,

				  size_t len);

char *efivar_get_utf8name(const efi_char16_t *name16, efi_guid_t *vendor);

bool efivarfs_variable_is_present(efi_char16_t *variable_name,

				  efi_guid_t *vendor, void *data);



extern const struct file_operations efivarfs_file_operations;

extern const struct inode_operations efivarfs_dir_inode_operations;

fs/efivarfs/super.c

+29 −0
Original line number Diff line number Diff line
@@ -181,6 +181,35 @@ static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name) 
	return ERR_PTR(-ENOMEM);

}



bool efivarfs_variable_is_present(efi_char16_t *variable_name,

				  efi_guid_t *vendor, void *data)

{

	char *name = efivar_get_utf8name(variable_name, vendor);

	struct super_block *sb = data;

	struct dentry *dentry;

	struct qstr qstr;



	if (!name)

		/*

		 * If the allocation failed there'll already be an

		 * error in the log (and likely a huge and growing

		 * number of them since they system will be under

		 * extreme memory pressure), so simply assume

		 * collision for safety but don't add to the log

		 * flood.

		 */

		return true;



	qstr.name = name;

	qstr.len = strlen(name);

	dentry = d_hash_and_lookup(sb->s_root, &qstr);

	kfree(name);

	if (!IS_ERR_OR_NULL(dentry))

		dput(dentry);



	return dentry != NULL;

}



static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,

			     unsigned long name_size, void *data,

			     struct list_head *list)

fs/efivarfs/vars.c

+2 −24
Original line number Diff line number Diff line
@@ -313,28 +313,6 @@ efivar_variable_is_removable(efi_guid_t vendor, const char *var_name, 
	return found;

}



static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor,

				struct list_head *head)

{

	struct efivar_entry *entry, *n;

	unsigned long strsize1, strsize2;

	bool found = false;



	strsize1 = ucs2_strsize(variable_name, EFI_VAR_NAME_LEN);

	list_for_each_entry_safe(entry, n, head, list) {

		strsize2 = ucs2_strsize(entry->var.VariableName, EFI_VAR_NAME_LEN);

		if (strsize1 == strsize2 &&

			!memcmp(variable_name, &(entry->var.VariableName),

				strsize2) &&

			!efi_guidcmp(entry->var.VendorGuid,

				*vendor)) {

			found = true;

			break;

		}

	}

	return found;

}



/*

 * Returns the size of variable_name, in bytes, including the

 * terminating NULL character, or variable_name_size if no NULL
@@ -439,8 +417,8 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *, 
			 * we'll ever see a different variable name,

			 * and may end up looping here forever.

			 */

			if (variable_is_present(variable_name, &vendor_guid,

						head)) {

			if (efivarfs_variable_is_present(variable_name,

							 &vendor_guid, data)) {

				dup_variable_bug(variable_name, &vendor_guid,

						 variable_name_size);

				status = EFI_NOT_FOUND;