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: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/fs/efivarfs/internal.h b/fs/efivarfs/internal.h
index c10efc1ad0a7bb86f7c0e945ded4de1031dfa039..597ccaa60d3731eff1f4e7cf3f3c6920544aec0b 100644 (file)
--- a/fs/efivarfs/internal.h
+++ b/fs/efivarfs/internal.h
@@ -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;

diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index b22441f7f7c6a1e1118f51805d6be54dcb7b49c2..9e90823f800952c442380fd76f8073a32bbbf348 100644 (file)
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -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)

diff --git a/fs/efivarfs/vars.c b/fs/efivarfs/vars.c
index 13594087d9ee20885b1ce4d66407610cddde7cec..b2fc5bdc759a4e03ee5a1b7e2d67fb2d8ea2b797 100644 (file)
--- a/fs/efivarfs/vars.c
+++ b/fs/efivarfs/vars.c
@@ -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;