return 0;
src_rsv = trans->block_rsv;
- dst_rsv = &root->fs_info->global_block_rsv;
+ dst_rsv = &root->fs_info->delayed_block_rsv;
num_bytes = btrfs_calc_trans_metadata_size(root, 1);
ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
if (!item->bytes_reserved)
return;
- rsv = &root->fs_info->global_block_rsv;
+ rsv = &root->fs_info->delayed_block_rsv;
btrfs_block_rsv_release(root, rsv,
item->bytes_reserved);
}
static int btrfs_delayed_inode_reserve_metadata(
struct btrfs_trans_handle *trans,
struct btrfs_root *root,
+ struct inode *inode,
struct btrfs_delayed_node *node)
{
struct btrfs_block_rsv *src_rsv;
struct btrfs_block_rsv *dst_rsv;
u64 num_bytes;
int ret;
-
- if (!trans->bytes_reserved)
- return 0;
+ int release = false;
src_rsv = trans->block_rsv;
- dst_rsv = &root->fs_info->global_block_rsv;
+ dst_rsv = &root->fs_info->delayed_block_rsv;
num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+
+ /*
+ * btrfs_dirty_inode will update the inode under btrfs_join_transaction
+ * which doesn't reserve space for speed. This is a problem since we
+ * still need to reserve space for this update, so try to reserve the
+ * space.
+ *
+ * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
+ * we're accounted for.
+ */
+ if (!trans->bytes_reserved &&
+ src_rsv != &root->fs_info->delalloc_block_rsv) {
+ ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
+ /*
+ * Since we're under a transaction reserve_metadata_bytes could
+ * try to commit the transaction which will make it return
+ * EAGAIN to make us stop the transaction we have, so return
+ * ENOSPC instead so that btrfs_dirty_inode knows what to do.
+ */
+ if (ret == -EAGAIN)
+ ret = -ENOSPC;
+ if (!ret)
+ node->bytes_reserved = num_bytes;
+ return ret;
+ } else if (src_rsv == &root->fs_info->delalloc_block_rsv) {
+ spin_lock(&BTRFS_I(inode)->lock);
+ if (BTRFS_I(inode)->delalloc_meta_reserved) {
+ BTRFS_I(inode)->delalloc_meta_reserved = 0;
+ spin_unlock(&BTRFS_I(inode)->lock);
+ release = true;
+ goto migrate;
+ }
+ spin_unlock(&BTRFS_I(inode)->lock);
+
+ /* Ok we didn't have space pre-reserved. This shouldn't happen
+ * too often but it can happen if we do delalloc to an existing
+ * inode which gets dirtied because of the time update, and then
+ * isn't touched again until after the transaction commits and
+ * then we try to write out the data. First try to be nice and
+ * reserve something strictly for us. If not be a pain and try
+ * to steal from the delalloc block rsv.
+ */
+ ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
+ if (!ret)
+ goto out;
+
+ ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
+ if (!ret)
+ goto out;
+
+ /*
+ * Ok this is a problem, let's just steal from the global rsv
+ * since this really shouldn't happen that often.
+ */
+ WARN_ON(1);
+ ret = btrfs_block_rsv_migrate(&root->fs_info->global_block_rsv,
+ dst_rsv, num_bytes);
+ goto out;
+ }
+
+migrate:
ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
+
+out:
+ /*
+ * Migrate only takes a reservation, it doesn't touch the size of the
+ * block_rsv. This is to simplify people who don't normally have things
+ * migrated from their block rsv. If they go to release their
+ * reservation, that will decrease the size as well, so if migrate
+ * reduced size we'd end up with a negative size. But for the
+ * delalloc_meta_reserved stuff we will only know to drop 1 reservation,
+ * but we could in fact do this reserve/migrate dance several times
+ * between the time we did the original reservation and we'd clean it
+ * up. So to take care of this, release the space for the meta
+ * reservation here. I think it may be time for a documentation page on
+ * how block rsvs. work.
+ */
if (!ret)
node->bytes_reserved = num_bytes;
+ if (release)
+ btrfs_block_rsv_release(root, src_rsv, num_bytes);
+
return ret;
}
if (!node->bytes_reserved)
return;
- rsv = &root->fs_info->global_block_rsv;
+ rsv = &root->fs_info->delayed_block_rsv;
btrfs_block_rsv_release(root, rsv,
node->bytes_reserved);
node->bytes_reserved = 0;
path->leave_spinning = 1;
block_rsv = trans->block_rsv;
- trans->block_rsv = &root->fs_info->global_block_rsv;
+ trans->block_rsv = &root->fs_info->delayed_block_rsv;
delayed_root = btrfs_get_delayed_root(root);
path->leave_spinning = 1;
block_rsv = trans->block_rsv;
- trans->block_rsv = &node->root->fs_info->global_block_rsv;
+ trans->block_rsv = &node->root->fs_info->delayed_block_rsv;
ret = btrfs_insert_delayed_items(trans, path, node->root, node);
if (!ret)
goto free_path;
block_rsv = trans->block_rsv;
- trans->block_rsv = &root->fs_info->global_block_rsv;
+ trans->block_rsv = &root->fs_info->delayed_block_rsv;
ret = btrfs_insert_delayed_items(trans, path, root, delayed_node);
if (!ret)
goto release_node;
}
- ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);
- /*
- * we must reserve enough space when we start a new transaction,
- * so reserving metadata failure is impossible
- */
- BUG_ON(ret);
+ ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
+ delayed_node);
+ if (ret)
+ goto release_node;
fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
delayed_node->inode_dirty = 1;
git.openpandora.org / pandora-kernel.git / blobdiff