Hello, This patch updates the allocator for the new space balancing code. It adds reserved extents accounting, changes a few ENOSPC check, and makes btrfs_find_block_group not return NULL for volumes that have been ebalanced. Regards Yan Zheng --- diff -r 4b327f4fcee0 ctree.h --- a/ctree.h Tue Sep 23 13:14:14 2008 -0400 +++ b/ctree.h Thu Sep 25 16:00:18 2008 +0800 @@ -498,6 +498,7 @@ u64 total_bytes; u64 bytes_used; u64 bytes_pinned; + u64 bytes_reserved; int full; int force_alloc; struct list_head list; @@ -519,6 +520,7 @@ struct btrfs_block_group_item item; spinlock_t lock; u64 pinned; + u64 reserved; u64 flags; int cached; int ro; diff -r 4b327f4fcee0 extent-tree.c --- a/extent-tree.c Tue Sep 23 13:14:14 2008 -0400 +++ b/extent-tree.c Thu Sep 25 16:00:18 2008 +0800 @@ -325,12 +325,9 @@ struct btrfs_block_group_cache *cache = *cache_ret; struct btrfs_free_space *info = NULL; u64 last; - u64 total_fs_bytes; u64 search_start = *start_ret; WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); - total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); - if (!cache) goto out; @@ -354,7 +351,7 @@ last = cache->key.objectid + cache->key.offset; cache = btrfs_lookup_first_block_group(root->fs_info, last); - if (!cache || cache->key.objectid >= total_fs_bytes) + if (!cache) goto out; *cache_ret = cache; @@ -385,7 +382,6 @@ return found; } return NULL; - } static struct btrfs_block_group_cache * @@ -396,7 +392,6 @@ struct btrfs_block_group_cache *cache; struct btrfs_block_group_cache *found_group = NULL; struct btrfs_fs_info *info = root->fs_info; - struct btrfs_space_info *sinfo; u64 used; u64 last = 0; u64 free_check; @@ -413,7 +408,7 @@ if (shint && block_group_bits(shint, data) && !shint->ro) { spin_lock(&shint->lock); used = btrfs_block_group_used(&shint->item); - if (used + shint->pinned < + if (used + shint->pinned + shint->reserved < div_factor(shint->key.offset, factor)) { spin_unlock(&shint->lock); return shint; @@ -424,7 +419,7 @@ if (hint && !hint->ro && block_group_bits(hint, data)) { spin_lock(&hint->lock); used = btrfs_block_group_used(&hint->item); - if (used + hint->pinned < + if (used + hint->pinned + hint->reserved < div_factor(hint->key.offset, factor)) { spin_unlock(&hint->lock); return hint; @@ -437,27 +432,9 @@ else last = search_start; } - sinfo = __find_space_info(root->fs_info, data); - if (!sinfo) - goto found; -again: - while(1) { - struct list_head *l; - - cache = NULL; - - spin_lock(&sinfo->lock); - list_for_each(l, &sinfo->block_groups) { - struct btrfs_block_group_cache *entry; - entry = list_entry(l, struct btrfs_block_group_cache, - list); - if ((entry->key.objectid >= last) && - (!cache || (entry->key.objectid < - cache->key.objectid))) - cache = entry; - } - spin_unlock(&sinfo->lock); - +again: + while (1) { + cache = btrfs_lookup_first_block_group(root->fs_info, last); if (!cache) break; @@ -467,7 +444,8 @@ if (!cache->ro && block_group_bits(cache, data)) { free_check = div_factor(cache->key.offset, factor); - if (used + cache->pinned < free_check) { + if (used + cache->pinned + cache->reserved < + free_check) { found_group = cache; spin_unlock(&cache->lock); goto found; @@ -1414,6 +1392,7 @@ if (!cache) break; + cache->dirty = 0; last += cache->key.offset; err = write_one_cache_group(trans, root, @@ -1427,8 +1406,6 @@ werr = err; continue; } - - cache->dirty = 0; } btrfs_free_path(path); mutex_unlock(&root->fs_info->alloc_mutex); @@ -1460,6 +1437,7 @@ found->total_bytes = total_bytes; found->bytes_used = bytes_used; found->bytes_pinned = 0; + found->bytes_reserved = 0; found->full = 0; found->force_alloc = 0; *space_info = found; @@ -1539,8 +1517,8 @@ thresh = div_factor(space_info->total_bytes, 6); if (!force && - (space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) < - thresh) + (space_info->bytes_used + space_info->bytes_pinned + + space_info->bytes_reserved + alloc_bytes) < thresh) goto out; mutex_lock(&extent_root->fs_info->chunk_mutex); @@ -1621,7 +1599,6 @@ return cache->key.objectid; } - int btrfs_update_pinned_extents(struct btrfs_root *root, u64 bytenr, u64 num, int pin) { @@ -1639,30 +1616,51 @@ } while (num > 0) { cache = btrfs_lookup_block_group(fs_info, bytenr); - if (!cache) { - u64 first = first_logical_byte(root, bytenr); - WARN_ON(first < bytenr); - len = min(first - bytenr, num); - } else { - len = min(num, cache->key.offset - - (bytenr - cache->key.objectid)); - } + BUG_ON(!cache); + len = min(num, cache->key.offset - + (bytenr - cache->key.objectid)); if (pin) { - if (cache) { - spin_lock(&cache->lock); - cache->pinned += len; - cache->space_info->bytes_pinned += len; - spin_unlock(&cache->lock); - } + spin_lock(&cache->lock); + cache->pinned += len; + cache->space_info->bytes_pinned += len; + spin_unlock(&cache->lock); fs_info->total_pinned += len; } else { - if (cache) { - spin_lock(&cache->lock); - cache->pinned -= len; - cache->space_info->bytes_pinned -= len; - spin_unlock(&cache->lock); - } + spin_lock(&cache->lock); + cache->pinned -= len; + cache->space_info->bytes_pinned -= len; + spin_unlock(&cache->lock); fs_info->total_pinned -= len; + } + bytenr += len; + num -= len; + } + return 0; +} + +static int update_reserved_extents(struct btrfs_root *root, + u64 bytenr, u64 num, int reserve) +{ + u64 len; + struct btrfs_block_group_cache *cache; + struct btrfs_fs_info *fs_info = root->fs_info; + + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); + while (num > 0) { + cache = btrfs_lookup_block_group(fs_info, bytenr); + BUG_ON(!cache); + len = min(num, cache->key.offset - + (bytenr - cache->key.objectid)); + if (reserve) { + spin_lock(&cache->lock); + cache->reserved += len; + cache->space_info->bytes_reserved += len; + spin_unlock(&cache->lock); + } else { + spin_lock(&cache->lock); + cache->reserved -= len; + cache->space_info->bytes_reserved -= len; + spin_unlock(&cache->lock); } bytenr += len; num -= len; @@ -2126,6 +2124,7 @@ cache = btrfs_lookup_block_group(root->fs_info, bytenr); BUG_ON(!cache); btrfs_add_free_space(cache, bytenr, num_bytes); + update_reserved_extents(root, bytenr, num_bytes, 0); return 0; } pin = 1; @@ -2225,14 +2224,11 @@ search_start = max(search_start, first_logical_byte(root, 0)); orig_search_start = search_start; - if (search_end == (u64)-1) - search_end = btrfs_super_total_bytes(&info->super_copy); - search_start = max(search_start, hint_byte); total_needed += empty_size; new_group: - block_group = btrfs_lookup_block_group(info, search_start); + block_group = btrfs_lookup_first_block_group(info, search_start); /* * Ok this looks a little tricky, buts its really simple. First if we @@ -2257,12 +2253,8 @@ ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024, data, 1); - if (ret < 0) { - struct btrfs_space_info *info; - - info = __find_space_info(root->fs_info, data); + if (ret < 0) goto error; - } BUG_ON(ret); chunk_alloc_done = 1; search_start = orig_search_start; @@ -2378,22 +2370,24 @@ struct list_head *l; printk(KERN_INFO "space_info has %Lu free, is %sfull\n", - info->total_bytes - info->bytes_used - info->bytes_pinned, - (info->full) ? "" : "not "); + info->total_bytes - info->bytes_used - info->bytes_pinned - + info->bytes_reserved, (info->full) ? "" : "not "); spin_lock(&info->lock); list_for_each(l, &info->block_groups) { cache = list_entry(l, struct btrfs_block_group_cache, list); spin_lock(&cache->lock); printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used " - "%Lu pinned\n", + "%Lu pinned %Lu reserved\n", cache->key.objectid, cache->key.offset, - btrfs_block_group_used(&cache->item), cache->pinned); + btrfs_block_group_used(&cache->item), + cache->pinned, cache->reserved); btrfs_dump_free_space(cache, bytes); spin_unlock(&cache->lock); } spin_unlock(&info->lock); } + static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 num_bytes, u64 min_alloc_size, @@ -2500,6 +2494,7 @@ ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size, empty_size, hint_byte, search_end, ins, data); + update_reserved_extents(root, ins->objectid, ins->offset, 1); maybe_unlock_mutex(root); return ret; } @@ -2625,6 +2620,7 @@ ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid, ref_generation, owner, owner_offset, ins); + update_reserved_extents(root, ins->objectid, ins->offset, 0); maybe_unlock_mutex(root); return ret; } @@ -2685,6 +2681,8 @@ owner_objectid, owner_offset, ins); BUG_ON(ret); + } else { + update_reserved_extents(root, ins->objectid, ins->offset, 1); } maybe_unlock_mutex(root); return ret; @@ -3970,10 +3968,6 @@ ret = btrfs_add_block_group_cache(root->fs_info, cache); BUG_ON(ret); - - if (key.objectid >- btrfs_super_total_bytes(&info->super_copy)) - break; } ret = 0; error: -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at vger.kernel.org/majordomo-info.html