From: Chris Mason Date: Wed, 23 Jul 2008 03:06:41 +0000 (-0400) Subject: Btrfs: alloc_mutex latency reduction X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c286ac48ed7aaf53586f575af6053ae2a0f8554a;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git Btrfs: alloc_mutex latency reduction This releases the alloc_mutex in a few places that hold it for over long operations. btrfs_lookup_block_group is changed so that it doesn't need the mutex at all. Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index eeb5afa6e9b1..90504ba7f838 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -483,6 +483,7 @@ struct btrfs_block_group_cache { struct btrfs_key key; struct btrfs_block_group_item item; struct btrfs_space_info *space_info; + spinlock_t lock; u64 pinned; u64 flags; int cached; diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 72fa28236e5d..febc6295c7a9 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -319,7 +319,7 @@ no_cache: cache = btrfs_lookup_first_block_group(root->fs_info, last); } cache_miss = 0; - cache = __btrfs_find_block_group(root, cache, last, data, 0); + cache = btrfs_find_block_group(root, cache, last, data, 0); if (!cache) goto no_cache; *cache_ret = cache; @@ -379,19 +379,25 @@ __btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache *shint; shint = btrfs_lookup_first_block_group(info, search_start); if (shint && block_group_bits(shint, data) && !shint->ro) { + spin_lock(&shint->lock); used = btrfs_block_group_used(&shint->item); if (used + shint->pinned < div_factor(shint->key.offset, factor)) { + spin_unlock(&shint->lock); return shint; } + spin_unlock(&shint->lock); } } if (hint && !hint->ro && block_group_bits(hint, data)) { + spin_lock(&hint->lock); used = btrfs_block_group_used(&hint->item); if (used + hint->pinned < div_factor(hint->key.offset, factor)) { + spin_unlock(&hint->lock); return hint; } + spin_unlock(&hint->lock); last = hint->key.objectid + hint->key.offset; } else { if (hint) @@ -413,6 +419,7 @@ again: } cache = (struct btrfs_block_group_cache *)(unsigned long)ptr; + spin_lock(&cache->lock); last = cache->key.objectid + cache->key.offset; used = btrfs_block_group_used(&cache->item); @@ -420,9 +427,11 @@ again: free_check = div_factor(cache->key.offset, factor); if (used + cache->pinned < free_check) { found_group = cache; + spin_unlock(&cache->lock); goto found; } } + spin_unlock(&cache->lock); cond_resched(); } if (!wrapped) { @@ -447,9 +456,7 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root, { struct btrfs_block_group_cache *ret; - mutex_lock(&root->fs_info->alloc_mutex); ret = __btrfs_find_block_group(root, hint, search_start, data, owner); - mutex_unlock(&root->fs_info->alloc_mutex); return ret; } static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation, @@ -1262,21 +1269,25 @@ static int update_block_group(struct btrfs_trans_handle *trans, set_extent_bits(&info->block_group_cache, start, end, BLOCK_GROUP_DIRTY, GFP_NOFS); + spin_lock(&cache->lock); old_val = btrfs_block_group_used(&cache->item); num_bytes = min(total, cache->key.offset - byte_in_group); if (alloc) { old_val += num_bytes; cache->space_info->bytes_used += num_bytes; + btrfs_set_block_group_used(&cache->item, old_val); + spin_unlock(&cache->lock); } else { old_val -= num_bytes; cache->space_info->bytes_used -= num_bytes; + btrfs_set_block_group_used(&cache->item, old_val); + spin_unlock(&cache->lock); if (mark_free) { set_extent_dirty(&info->free_space_cache, bytenr, bytenr + num_bytes - 1, GFP_NOFS); } } - btrfs_set_block_group_used(&cache->item, old_val); total -= num_bytes; bytenr += num_bytes; } @@ -1325,14 +1336,18 @@ static int update_pinned_extents(struct btrfs_root *root, } if (pin) { if (cache) { + 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); } fs_info->total_pinned -= len; } @@ -1380,6 +1395,11 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, update_pinned_extents(root, start, end + 1 - start, 0); clear_extent_dirty(unpin, start, end, GFP_NOFS); set_extent_dirty(free_space_cache, start, end, GFP_NOFS); + if (need_resched()) { + mutex_unlock(&root->fs_info->alloc_mutex); + cond_resched(); + mutex_lock(&root->fs_info->alloc_mutex); + } } mutex_unlock(&root->fs_info->alloc_mutex); return 0; @@ -1417,8 +1437,16 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, &extent_item, sizeof(extent_item)); clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED, GFP_NOFS); - eb = read_tree_block(extent_root, ins.objectid, ins.offset, - trans->transid); + + eb = btrfs_find_tree_block(extent_root, ins.objectid, + ins.offset); + + if (!btrfs_buffer_uptodate(eb, trans->transid)) { + mutex_unlock(&extent_root->fs_info->alloc_mutex); + btrfs_read_buffer(eb, trans->transid); + mutex_lock(&extent_root->fs_info->alloc_mutex); + } + btrfs_tree_lock(eb); level = btrfs_header_level(eb); if (level == 0) { @@ -1437,6 +1465,11 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, 0, level, btrfs_disk_key_objectid(&first)); BUG_ON(err); + if (need_resched()) { + mutex_unlock(&extent_root->fs_info->alloc_mutex); + cond_resched(); + mutex_lock(&extent_root->fs_info->alloc_mutex); + } } btrfs_free_path(path); return 0; @@ -1640,15 +1673,28 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct EXTENT_LOCKED); if (ret) break; - update_pinned_extents(extent_root, start, end + 1 - start, 1); clear_extent_bits(pending_del, start, end, EXTENT_LOCKED, GFP_NOFS); - ret = __free_extent(trans, extent_root, - start, end + 1 - start, - extent_root->root_key.objectid, - 0, 0, 0, 0, 0); + if (!test_range_bit(&extent_root->fs_info->extent_ins, + start, end, EXTENT_LOCKED, 0)) { + update_pinned_extents(extent_root, start, + end + 1 - start, 1); + ret = __free_extent(trans, extent_root, + start, end + 1 - start, + extent_root->root_key.objectid, + 0, 0, 0, 0, 0); + } else { + clear_extent_bits(&extent_root->fs_info->extent_ins, + start, end, EXTENT_LOCKED, GFP_NOFS); + } if (ret) err = ret; + + if (need_resched()) { + mutex_unlock(&extent_root->fs_info->alloc_mutex); + cond_resched(); + mutex_lock(&extent_root->fs_info->alloc_mutex); + } } return err; } @@ -1768,12 +1814,12 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans, block_group = btrfs_lookup_first_block_group(info, hint_byte); if (!block_group) hint_byte = search_start; - block_group = __btrfs_find_block_group(root, block_group, + block_group = btrfs_find_block_group(root, block_group, hint_byte, data, 1); if (last_ptr && *last_ptr == 0 && block_group) hint_byte = block_group->key.objectid; } else { - block_group = __btrfs_find_block_group(root, + block_group = btrfs_find_block_group(root, trans->block_group, search_start, data, 1); } @@ -1895,7 +1941,7 @@ enospc: } block_group = btrfs_lookup_first_block_group(info, search_start); cond_resched(); - block_group = __btrfs_find_block_group(root, block_group, + block_group = btrfs_find_block_group(root, block_group, search_start, data, 0); goto check_failed; @@ -3032,11 +3078,14 @@ int __alloc_chunk_for_shrink(struct btrfs_root *root, u64 new_alloc_flags; u64 calc; + spin_lock(&shrink_block_group->lock); if (btrfs_block_group_used(&shrink_block_group->item) > 0) { - + spin_unlock(&shrink_block_group->lock); mutex_unlock(&root->fs_info->alloc_mutex); + trans = btrfs_start_transaction(root, 1); mutex_lock(&root->fs_info->alloc_mutex); + spin_lock(&shrink_block_group->lock); new_alloc_flags = update_block_group_flags(root, shrink_block_group->flags); @@ -3046,13 +3095,16 @@ int __alloc_chunk_for_shrink(struct btrfs_root *root, } else { calc = shrink_block_group->key.offset; } + spin_unlock(&shrink_block_group->lock); + do_chunk_alloc(trans, root->fs_info->extent_root, calc + 2 * 1024 * 1024, new_alloc_flags, force); mutex_unlock(&root->fs_info->alloc_mutex); btrfs_end_transaction(trans, root); mutex_lock(&root->fs_info->alloc_mutex); - } + } else + spin_unlock(&shrink_block_group->lock); return 0; } @@ -3199,6 +3251,7 @@ next: mutex_unlock(&root->fs_info->alloc_mutex); trans = btrfs_start_transaction(root, 1); + mutex_lock(&root->fs_info->alloc_mutex); memcpy(&key, &shrink_block_group->key, sizeof(key)); @@ -3316,6 +3369,7 @@ int btrfs_read_block_groups(struct btrfs_root *root) break; } + spin_lock_init(&cache->lock); read_extent_buffer(leaf, &cache->item, btrfs_item_ptr_offset(leaf, path->slots[0]), sizeof(cache->item)); @@ -3343,10 +3397,12 @@ int btrfs_read_block_groups(struct btrfs_root *root) /* use EXTENT_LOCKED to prevent merging */ set_extent_bits(block_group_cache, found_key.objectid, found_key.objectid + found_key.offset - 1, - bit | EXTENT_LOCKED, GFP_NOFS); + EXTENT_LOCKED, GFP_NOFS); set_state_private(block_group_cache, found_key.objectid, (unsigned long)cache); - + set_extent_bits(block_group_cache, found_key.objectid, + found_key.objectid + found_key.offset - 1, + bit | EXTENT_LOCKED, GFP_NOFS); if (key.objectid >= btrfs_super_total_bytes(&info->super_copy)) break; @@ -3377,6 +3433,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, BUG_ON(!cache); cache->key.objectid = chunk_offset; cache->key.offset = size; + spin_lock_init(&cache->lock); btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY); btrfs_set_block_group_used(&cache->item, bytes_used); @@ -3391,10 +3448,13 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, bit = block_group_state_bits(type); set_extent_bits(block_group_cache, chunk_offset, chunk_offset + size - 1, - bit | EXTENT_LOCKED, GFP_NOFS); - + EXTENT_LOCKED, GFP_NOFS); set_state_private(block_group_cache, chunk_offset, (unsigned long)cache); + set_extent_bits(block_group_cache, chunk_offset, + chunk_offset + size - 1, + bit | EXTENT_LOCKED, GFP_NOFS); + ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item, sizeof(cache->item)); BUG_ON(ret);