efivarfs: Move to fs/efivarfs
Now that efivarfs uses the efivar API, move it out of efivars.c and
into fs/efivarfs where it belongs. This move will eventually allow us
to enable the efivarfs code without having to also enable
CONFIG_EFI_VARS built, and vice versa.
Furthermore, things like,
mount -t efivarfs none /sys/firmware/efi/efivars
will now work if efivarfs is built as a module without requiring the
use of MODULE_ALIAS(), which would have been necessary when the
efivarfs code was part of efivars.c.
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Tom Gundersen <teg@jklm.no>
Tested-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
diff --git a/fs/efivarfs/inode.c b/fs/efivarfs/inode.c
new file mode 100644
index 0000000..640e289
--- /dev/null
+++ b/fs/efivarfs/inode.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/efi.h>
+#include <linux/fs.h>
+#include <linux/ctype.h>
+
+#include "internal.h"
+
+struct inode *efivarfs_get_inode(struct super_block *sb,
+ const struct inode *dir, int mode, dev_t dev)
+{
+ struct inode *inode = new_inode(sb);
+
+ if (inode) {
+ inode->i_ino = get_next_ino();
+ inode->i_mode = mode;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ switch (mode & S_IFMT) {
+ case S_IFREG:
+ inode->i_fop = &efivarfs_file_operations;
+ break;
+ case S_IFDIR:
+ inode->i_op = &efivarfs_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ inc_nlink(inode);
+ break;
+ }
+ }
+ return inode;
+}
+
+/*
+ * Return true if 'str' is a valid efivarfs filename of the form,
+ *
+ * VariableName-12345678-1234-1234-1234-1234567891bc
+ */
+bool efivarfs_valid_name(const char *str, int len)
+{
+ static const char dashes[EFI_VARIABLE_GUID_LEN] = {
+ [8] = 1, [13] = 1, [18] = 1, [23] = 1
+ };
+ const char *s = str + len - EFI_VARIABLE_GUID_LEN;
+ int i;
+
+ /*
+ * We need a GUID, plus at least one letter for the variable name,
+ * plus the '-' separator
+ */
+ if (len < EFI_VARIABLE_GUID_LEN + 2)
+ return false;
+
+ /* GUID must be preceded by a '-' */
+ if (*(s - 1) != '-')
+ return false;
+
+ /*
+ * Validate that 's' is of the correct format, e.g.
+ *
+ * 12345678-1234-1234-1234-123456789abc
+ */
+ for (i = 0; i < EFI_VARIABLE_GUID_LEN; i++) {
+ if (dashes[i]) {
+ if (*s++ != '-')
+ return false;
+ } else {
+ if (!isxdigit(*s++))
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid)
+{
+ guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]);
+ guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]);
+ guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]);
+ guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]);
+ guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]);
+ guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]);
+ guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]);
+ guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]);
+ guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]);
+ guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]);
+ guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]);
+ guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]);
+ guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]);
+ guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]);
+ guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]);
+ guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]);
+}
+
+static int efivarfs_create(struct inode *dir, struct dentry *dentry,
+ umode_t mode, bool excl)
+{
+ struct inode *inode;
+ struct efivar_entry *var;
+ int namelen, i = 0, err = 0;
+
+ if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
+ return -EINVAL;
+
+ inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
+ if (!inode)
+ return -ENOMEM;
+
+ var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
+ if (!var) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ /* length of the variable name itself: remove GUID and separator */
+ namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1;
+
+ efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1,
+ &var->var.VendorGuid);
+
+ for (i = 0; i < namelen; i++)
+ var->var.VariableName[i] = dentry->d_name.name[i];
+
+ var->var.VariableName[i] = '\0';
+
+ inode->i_private = var;
+
+ efivar_entry_add(var, &efivarfs_list);
+ d_instantiate(dentry, inode);
+ dget(dentry);
+out:
+ if (err) {
+ kfree(var);
+ iput(inode);
+ }
+ return err;
+}
+
+static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct efivar_entry *var = dentry->d_inode->i_private;
+
+ if (efivar_entry_delete(var))
+ return -EINVAL;
+
+ drop_nlink(dentry->d_inode);
+ dput(dentry);
+ return 0;
+};
+
+/*
+ * Handle negative dentry.
+ */
+static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ if (dentry->d_name.len > NAME_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+ d_add(dentry, NULL);
+ return NULL;
+}
+
+const struct inode_operations efivarfs_dir_inode_operations = {
+ .lookup = efivarfs_lookup,
+ .unlink = efivarfs_unlink,
+ .create = efivarfs_create,
+};