[PATCH 4/6] efivarfs: move freeing of variable entry into evict_inode

[James Bottomley <James.Bottomley@HansenPartnership.com>]

Make the inodes the default management vehicle for struct
efivar_entry, so they are now all freed automatically if the file is
removed and on unmount in kill_litter_super().  Remove the now
superfluous iterator to free the entries after kill_litter_super().

Also fixes a bug where some entry freeing was missing causing efivarfs
to leak memory.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
---
 fs/efivarfs/internal.h |  1 -
 fs/efivarfs/super.c    | 15 +++++++--------
 fs/efivarfs/vars.c     | 39 +++------------------------------------
 3 files changed, 10 insertions(+), 45 deletions(-)

diff --git a/fs/efivarfs/internal.h b/fs/efivarfs/internal.h
index 84a36e6fb653..d768bfa7f12b 100644
--- a/fs/efivarfs/internal.h
+++ b/fs/efivarfs/internal.h
@@ -37,7 +37,6 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *,
 
 int efivar_entry_add(struct efivar_entry *entry, struct list_head *head);
 void __efivar_entry_add(struct efivar_entry *entry, struct list_head *head);
-void efivar_entry_remove(struct efivar_entry *entry);
 int efivar_entry_delete(struct efivar_entry *entry);
 
 int efivar_entry_size(struct efivar_entry *entry, unsigned long *size);
diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index dc3870ae784b..70b99f58c906 100644
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -41,6 +41,12 @@ static int efivarfs_ops_notifier(struct notifier_block *nb, unsigned long event,
 
 static void efivarfs_evict_inode(struct inode *inode)
 {
+	struct efivar_entry *entry = inode->i_private;
+
+	if (entry)  {
+		list_del(&entry->list);
+		kfree(entry);
+	}
 	clear_inode(inode);
 }
 
@@ -269,13 +275,6 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
 	return err;
 }
 
-static int efivarfs_destroy(struct efivar_entry *entry, void *data)
-{
-	efivar_entry_remove(entry);
-	kfree(entry);
-	return 0;
-}
-
 enum {
 	Opt_uid, Opt_gid,
 };
@@ -398,7 +397,7 @@ static void efivarfs_kill_sb(struct super_block *sb)
 	kill_litter_super(sb);
 
 	/* Remove all entries and destroy */
-	efivar_entry_iter(efivarfs_destroy, &sfi->efivarfs_list, NULL);
+	WARN_ON(!list_empty(&sfi->efivarfs_list));
 	kfree(sfi);
 }
 
diff --git a/fs/efivarfs/vars.c b/fs/efivarfs/vars.c
index f6380fdbe173..bda8e8b869e8 100644
--- a/fs/efivarfs/vars.c
+++ b/fs/efivarfs/vars.c
@@ -485,34 +485,6 @@ void __efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
 	list_add(&entry->list, head);
 }
 
-/**
- * efivar_entry_remove - remove entry from variable list
- * @entry: entry to remove from list
- *
- * Returns 0 on success, or a kernel error code on failure.
- */
-void efivar_entry_remove(struct efivar_entry *entry)
-{
-	list_del(&entry->list);
-}
-
-/*
- * efivar_entry_list_del_unlock - remove entry from variable list
- * @entry: entry to remove
- *
- * Remove @entry from the variable list and release the list lock.
- *
- * NOTE: slightly weird locking semantics here - we expect to be
- * called with the efivars lock already held, and we release it before
- * returning. This is because this function is usually called after
- * set_variable() while the lock is still held.
- */
-static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
-{
-	list_del(&entry->list);
-	efivar_unlock();
-}
-
 /**
  * efivar_entry_delete - delete variable and remove entry from list
  * @entry: entry containing variable to delete
@@ -536,12 +508,10 @@ int efivar_entry_delete(struct efivar_entry *entry)
 	status = efivar_set_variable_locked(entry->var.VariableName,
 					    &entry->var.VendorGuid,
 					    0, 0, NULL, false);
-	if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {
-		efivar_unlock();
+	efivar_unlock();
+	if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND))
 		return efi_status_to_err(status);
-	}
 
-	efivar_entry_list_del_unlock(entry);
 	return 0;
 }
 
@@ -679,10 +649,7 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
 				    &entry->var.VendorGuid,
 				    NULL, size, NULL);
 
-	if (status == EFI_NOT_FOUND)
-		efivar_entry_list_del_unlock(entry);
-	else
-		efivar_unlock();
+	efivar_unlock();
 
 	if (status && status != EFI_BUFFER_TOO_SMALL)
 		return efi_status_to_err(status);
-- 
2.35.3