static int efi_pstore_open(struct pstore_info *psi)
{
- efivar_entry_iter_begin();
psi->data = NULL;
return 0;
}
static int efi_pstore_close(struct pstore_info *psi)
{
- efivar_entry_iter_end();
psi->data = NULL;
return 0;
}
__efivar_entry_get(entry, &entry->var.Attributes,
&entry->var.DataSize, entry->var.Data);
size = entry->var.DataSize;
+ memcpy(*cb_data->buf, entry->var.Data,
+ (size_t)min_t(unsigned long, EFIVARS_DATA_SIZE_MAX, size));
- *cb_data->buf = kmemdup(entry->var.Data, size, GFP_KERNEL);
- if (*cb_data->buf == NULL)
- return -ENOMEM;
return size;
}
+/**
+ * efi_pstore_scan_sysfs_enter
+ * @entry: scanning entry
+ * @next: next entry
+ * @head: list head
+ */
+static void efi_pstore_scan_sysfs_enter(struct efivar_entry *pos,
+ struct efivar_entry *next,
+ struct list_head *head)
+{
+ pos->scanning = true;
+ if (&next->list != head)
+ next->scanning = true;
+}
+
+/**
+ * __efi_pstore_scan_sysfs_exit
+ * @entry: deleting entry
+ * @turn_off_scanning: Check if a scanning flag should be turned off
+ */
+static inline void __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry,
+ bool turn_off_scanning)
+{
+ if (entry->deleting) {
+ list_del(&entry->list);
+ efivar_entry_iter_end();
+ efivar_unregister(entry);
+ efivar_entry_iter_begin();
+ } else if (turn_off_scanning)
+ entry->scanning = false;
+}
+
+/**
+ * efi_pstore_scan_sysfs_exit
+ * @pos: scanning entry
+ * @next: next entry
+ * @head: list head
+ * @stop: a flag checking if scanning will stop
+ */
+static void efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
+ struct efivar_entry *next,
+ struct list_head *head, bool stop)
+{
+ __efi_pstore_scan_sysfs_exit(pos, true);
+ if (stop)
+ __efi_pstore_scan_sysfs_exit(next, &next->list != head);
+}
+
+/**
+ * efi_pstore_sysfs_entry_iter
+ *
+ * @data: function-specific data to pass to callback
+ * @pos: entry to begin iterating from
+ *
+ * You MUST call efivar_enter_iter_begin() before this function, and
+ * efivar_entry_iter_end() afterwards.
+ *
+ * It is possible to begin iteration from an arbitrary entry within
+ * the list by passing @pos. @pos is updated on return to point to
+ * the next entry of the last one passed to efi_pstore_read_func().
+ * To begin iterating from the beginning of the list @pos must be %NULL.
+ */
+static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
+{
+ struct efivar_entry *entry, *n;
+ struct list_head *head = &efivar_sysfs_list;
+ int size = 0;
+
+ if (!*pos) {
+ list_for_each_entry_safe(entry, n, head, list) {
+ efi_pstore_scan_sysfs_enter(entry, n, head);
+
+ size = efi_pstore_read_func(entry, data);
+ efi_pstore_scan_sysfs_exit(entry, n, head, size < 0);
+ if (size)
+ break;
+ }
+ *pos = n;
+ return size;
+ }
+
+ list_for_each_entry_safe_from((*pos), n, head, list) {
+ efi_pstore_scan_sysfs_enter((*pos), n, head);
+
+ size = efi_pstore_read_func((*pos), data);
+ efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0);
+ if (size)
+ break;
+ }
+ *pos = n;
+ return size;
+}
+
+/**
+ * efi_pstore_read
+ *
+ * This function returns a size of NVRAM entry logged via efi_pstore_write().
+ * The meaning and behavior of efi_pstore/pstore are as below.
+ *
+ * size > 0: Got data of an entry logged via efi_pstore_write() successfully,
+ * and pstore filesystem will continue reading subsequent entries.
+ * size == 0: Entry was not logged via efi_pstore_write(),
+ * and efi_pstore driver will continue reading subsequent entries.
+ * size < 0: Failed to get data of entry logging via efi_pstore_write(),
+ * and pstore will stop reading entry.
+ */
static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
int *count, struct timespec *timespec,
char **buf, bool *compressed,
struct pstore_info *psi)
{
struct pstore_read_data data;
+ ssize_t size;
data.id = id;
data.type = type;
data.compressed = compressed;
data.buf = buf;
- return __efivar_entry_iter(efi_pstore_read_func, &efivar_sysfs_list, &data,
- (struct efivar_entry **)&psi->data);
+ *data.buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
+ if (!*data.buf)
+ return -ENOMEM;
+
+ efivar_entry_iter_begin();
+ size = efi_pstore_sysfs_entry_iter(&data,
+ (struct efivar_entry **)&psi->data);
+ efivar_entry_iter_end();
+ if (size <= 0)
+ kfree(*data.buf);
+ return size;
}
static int efi_pstore_write(enum pstore_type_id type,
return 0;
}
+ if (entry->scanning) {
+ /*
+ * Skip deletion because this entry will be deleted
+ * after scanning is completed.
+ */
+ entry->deleting = true;
+ } else
+ list_del(&entry->list);
+
/* found */
__efivar_entry_delete(entry);
- list_del(&entry->list);
return 1;
}
efivar_entry_iter_begin();
found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);
- efivar_entry_iter_end();
- if (found)
+ if (found && !entry->scanning) {
+ efivar_entry_iter_end();
efivar_unregister(entry);
+ } else
+ efivar_entry_iter_end();
return 0;
}
projects / mirror_ubuntu-disco-kernel.git / commitdiff