[PATCH v2 4/6] efivarfs: move freeing of variable entry into evict_inode

James Bottomley
2025-01-07T02:37:47Z

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 597ccaa60d37..8d82fc8bca31 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 9e90823f8009..d7facc99b745 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);
}

@@ -278,13 +284,6 @@ 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,
};
@@ -407,7 +406,7 @@ 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 b2fc5bdc759a..bb9406e03a10 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