{
struct btrfs_device *device, *next;
+ struct block_device *latest_bdev = NULL;
+ u64 latest_devid = 0;
+ u64 latest_transid = 0;
+
mutex_lock(&uuid_mutex);
again:
/* This is the initialized path, it is safe to release the devices. */
list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
- if (device->in_fs_metadata)
+ if (device->in_fs_metadata) {
+ if (!latest_transid ||
+ device->generation > latest_transid) {
+ latest_devid = device->devid;
+ latest_transid = device->generation;
+ latest_bdev = device->bdev;
+ }
continue;
+ }
if (device->bdev) {
blkdev_put(device->bdev, device->mode);
goto again;
}
+ fs_devices->latest_bdev = latest_bdev;
+ fs_devices->latest_devid = latest_devid;
+ fs_devices->latest_trans = latest_transid;
+
mutex_unlock(&uuid_mutex);
return 0;
}
em = lookup_extent_mapping(em_tree, chunk_offset, 1);
read_unlock(&em_tree->lock);
- BUG_ON(em->start > chunk_offset ||
+ BUG_ON(!em || em->start > chunk_offset ||
em->start + em->len < chunk_offset);
map = (struct map_lookup *)em->bdev;
return -ENOMEM;
btrfs_set_buffer_uptodate(sb);
btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
+ /*
+ * The sb extent buffer is artifical and just used to read the system array.
+ * btrfs_set_buffer_uptodate() call does not properly mark all it's
+ * pages up-to-date when the page is larger: extent does not cover the
+ * whole page and consequently check_page_uptodate does not find all
+ * the page's extents up-to-date (the hole beyond sb),
+ * write_extent_buffer then triggers a WARN_ON.
+ *
+ * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
+ * but sb spans only this function. Add an explicit SetPageUptodate call
+ * to silence the warning eg. on PowerPC 64.
+ */
+ if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
+ SetPageUptodate(sb->first_page);
write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
array_size = btrfs_super_sys_array_size(super_copy);