+
+void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
+ struct btrfs_space_info *sinfo = block_rsv->space_info;
+ u64 num_bytes;
+
+ /*
+ * The global block rsv is based on the size of the extent tree, the
+ * checksum tree and the root tree. If the fs is empty we want to set
+ * it to a minimal amount for safety.
+ */
+ num_bytes = btrfs_root_used(&fs_info->extent_root->root_item) +
+ btrfs_root_used(&fs_info->csum_root->root_item) +
+ btrfs_root_used(&fs_info->tree_root->root_item);
+ num_bytes = max_t(u64, num_bytes, SZ_16M);
+
+ spin_lock(&sinfo->lock);
+ spin_lock(&block_rsv->lock);
+
+ block_rsv->size = min_t(u64, num_bytes, SZ_512M);
+
+ if (block_rsv->reserved < block_rsv->size) {
+ num_bytes = btrfs_space_info_used(sinfo, true);
+ if (sinfo->total_bytes > num_bytes) {
+ num_bytes = sinfo->total_bytes - num_bytes;
+ num_bytes = min(num_bytes,
+ block_rsv->size - block_rsv->reserved);
+ block_rsv->reserved += num_bytes;
+ btrfs_space_info_update_bytes_may_use(fs_info, sinfo,
+ num_bytes);
+ trace_btrfs_space_reservation(fs_info, "space_info",
+ sinfo->flags, num_bytes,
+ 1);
+ }
+ } else if (block_rsv->reserved > block_rsv->size) {
+ num_bytes = block_rsv->reserved - block_rsv->size;
+ btrfs_space_info_update_bytes_may_use(fs_info, sinfo,
+ -num_bytes);
+ trace_btrfs_space_reservation(fs_info, "space_info",
+ sinfo->flags, num_bytes, 0);
+ block_rsv->reserved = block_rsv->size;
+ }
+
+ if (block_rsv->reserved == block_rsv->size)
+ block_rsv->full = 1;
+ else
+ block_rsv->full = 0;
+
+ spin_unlock(&block_rsv->lock);
+ spin_unlock(&sinfo->lock);
+}
+
+void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_space_info *space_info;
+
+ space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
+ fs_info->chunk_block_rsv.space_info = space_info;
+
+ space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+ fs_info->global_block_rsv.space_info = space_info;
+ fs_info->trans_block_rsv.space_info = space_info;
+ fs_info->empty_block_rsv.space_info = space_info;
+ fs_info->delayed_block_rsv.space_info = space_info;
+ fs_info->delayed_refs_rsv.space_info = space_info;
+
+ fs_info->extent_root->block_rsv = &fs_info->delayed_refs_rsv;
+ fs_info->csum_root->block_rsv = &fs_info->delayed_refs_rsv;
+ fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
+ fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
+ if (fs_info->quota_root)
+ fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
+ fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
+
+ btrfs_update_global_block_rsv(fs_info);
+}
+
+void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info)
+{
+ btrfs_block_rsv_release(fs_info, &fs_info->global_block_rsv, (u64)-1);
+ WARN_ON(fs_info->trans_block_rsv.size > 0);
+ WARN_ON(fs_info->trans_block_rsv.reserved > 0);
+ WARN_ON(fs_info->chunk_block_rsv.size > 0);
+ WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
+ WARN_ON(fs_info->delayed_block_rsv.size > 0);
+ WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
+ WARN_ON(fs_info->delayed_refs_rsv.reserved > 0);
+ WARN_ON(fs_info->delayed_refs_rsv.size > 0);
+}
+
+static struct btrfs_block_rsv *get_block_rsv(
+ const struct btrfs_trans_handle *trans,
+ const struct btrfs_root *root)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_rsv *block_rsv = NULL;
+
+ if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
+ (root == fs_info->csum_root && trans->adding_csums) ||
+ (root == fs_info->uuid_root))
+ block_rsv = trans->block_rsv;
+
+ if (!block_rsv)
+ block_rsv = root->block_rsv;
+
+ if (!block_rsv)
+ block_rsv = &fs_info->empty_block_rsv;
+
+ return block_rsv;
+}
+
+struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u32 blocksize)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_rsv *block_rsv;
+ struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+ int ret;
+ bool global_updated = false;
+
+ block_rsv = get_block_rsv(trans, root);
+
+ if (unlikely(block_rsv->size == 0))
+ goto try_reserve;
+again:
+ ret = btrfs_block_rsv_use_bytes(block_rsv, blocksize);
+ if (!ret)
+ return block_rsv;
+
+ if (block_rsv->failfast)
+ return ERR_PTR(ret);
+
+ if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
+ global_updated = true;
+ btrfs_update_global_block_rsv(fs_info);
+ goto again;
+ }
+
+ /*
+ * The global reserve still exists to save us from ourselves, so don't
+ * warn_on if we are short on our delayed refs reserve.
+ */
+ if (block_rsv->type != BTRFS_BLOCK_RSV_DELREFS &&
+ btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
+ static DEFINE_RATELIMIT_STATE(_rs,
+ DEFAULT_RATELIMIT_INTERVAL * 10,
+ /*DEFAULT_RATELIMIT_BURST*/ 1);
+ if (__ratelimit(&_rs))
+ WARN(1, KERN_DEBUG
+ "BTRFS: block rsv returned %d\n", ret);
+ }
+try_reserve:
+ ret = btrfs_reserve_metadata_bytes(root, block_rsv, blocksize,
+ BTRFS_RESERVE_NO_FLUSH);
+ if (!ret)
+ return block_rsv;
+ /*
+ * If we couldn't reserve metadata bytes try and use some from
+ * the global reserve if its space type is the same as the global
+ * reservation.
+ */
+ if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
+ block_rsv->space_info == global_rsv->space_info) {
+ ret = btrfs_block_rsv_use_bytes(global_rsv, blocksize);
+ if (!ret)
+ return global_rsv;
+ }
+ return ERR_PTR(ret);
+}
git.samba.org / sfrench / cifs-2.6.git / commitdiff