From 2be12ef79fe9f5333cb9fadc85ef20b6832a56d7 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Mon, 22 May 2017 09:35:49 +0300 Subject: [PATCH] btrfs: Separate space_info create/update Currently the struct space_info creation code is intermixed in the udpate_space_info function. There are well-defined points at which the we actually want to create brand-new space_info structs (e.g. during mount of the filesystem as well as sometimes when adding/initialising new chunks). In such cases update_space_info is called with 0 as the bytes parameter. All of this makes for spaghetti code. Fix it by factoring out the creation code in a separate create_space_info structure. This also allows to simplify the internals. Also remove BUG_ON from do_alloc_chunk since the callers handle errors. Furthermore it will make the update_space_info function not fail, allowing us to remove error handling in callers. This will come in a follow up patch. Signed-off-by: Nikolay Borisov Reviewed-by: Jeff Mahoney Reviewed-by: Liu Bo Signed-off-by: David Sterba --- fs/btrfs/extent-tree.c | 132 ++++++++++++++++++++++++------------------------- 1 file changed, 66 insertions(+), 66 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index da8e49e04eb0..4e88df0b3f0a 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3925,15 +3925,60 @@ static const char *alloc_name(u64 flags) }; } +static int create_space_info(struct btrfs_fs_info *info, u64 flags, + struct btrfs_space_info **new) +{ + + struct btrfs_space_info *space_info; + int i; + int ret; + + space_info = kzalloc(sizeof(*space_info), GFP_NOFS); + if (!space_info) + return -ENOMEM; + + ret = percpu_counter_init(&space_info->total_bytes_pinned, 0, + GFP_KERNEL); + if (ret) { + kfree(space_info); + return ret; + } + + for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) + INIT_LIST_HEAD(&space_info->block_groups[i]); + init_rwsem(&space_info->groups_sem); + spin_lock_init(&space_info->lock); + space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK; + space_info->force_alloc = CHUNK_ALLOC_NO_FORCE; + init_waitqueue_head(&space_info->wait); + INIT_LIST_HEAD(&space_info->ro_bgs); + INIT_LIST_HEAD(&space_info->tickets); + INIT_LIST_HEAD(&space_info->priority_tickets); + + ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype, + info->space_info_kobj, "%s", + alloc_name(space_info->flags)); + if (ret) { + percpu_counter_destroy(&space_info->total_bytes_pinned); + kfree(space_info); + return ret; + } + + *new = space_info; + list_add_rcu(&space_info->list, &info->space_info); + if (flags & BTRFS_BLOCK_GROUP_DATA) + info->data_sinfo = space_info; + + return ret; +} + static int update_space_info(struct btrfs_fs_info *info, u64 flags, u64 total_bytes, u64 bytes_used, u64 bytes_readonly, struct btrfs_space_info **space_info) { struct btrfs_space_info *found; - int i; int factor; - int ret; if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) @@ -3957,54 +4002,6 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags, *space_info = found; return 0; } - found = kzalloc(sizeof(*found), GFP_NOFS); - if (!found) - return -ENOMEM; - - ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL); - if (ret) { - kfree(found); - return ret; - } - - for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) - INIT_LIST_HEAD(&found->block_groups[i]); - init_rwsem(&found->groups_sem); - spin_lock_init(&found->lock); - found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK; - found->total_bytes = total_bytes; - found->disk_total = total_bytes * factor; - found->bytes_used = bytes_used; - found->disk_used = bytes_used * factor; - found->bytes_pinned = 0; - found->bytes_reserved = 0; - found->bytes_readonly = bytes_readonly; - found->bytes_may_use = 0; - found->full = 0; - found->max_extent_size = 0; - found->force_alloc = CHUNK_ALLOC_NO_FORCE; - found->chunk_alloc = 0; - found->flush = 0; - init_waitqueue_head(&found->wait); - INIT_LIST_HEAD(&found->ro_bgs); - INIT_LIST_HEAD(&found->tickets); - INIT_LIST_HEAD(&found->priority_tickets); - - ret = kobject_init_and_add(&found->kobj, &space_info_ktype, - info->space_info_kobj, "%s", - alloc_name(found->flags)); - if (ret) { - percpu_counter_destroy(&found->total_bytes_pinned); - kfree(found); - return ret; - } - - *space_info = found; - list_add_rcu(&found->list, &info->space_info); - if (flags & BTRFS_BLOCK_GROUP_DATA) - info->data_sinfo = found; - - return ret; } static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) @@ -4521,10 +4518,10 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans, space_info = __find_space_info(fs_info, flags); if (!space_info) { - ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info); - BUG_ON(ret); /* -ENOMEM */ + ret = create_space_info(fs_info, flags, &space_info); + if (ret) + return ret; } - BUG_ON(!space_info); /* Logic error */ again: spin_lock(&space_info->lock); @@ -10225,16 +10222,19 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, } #endif /* - * Call to ensure the corresponding space_info object is created and - * assigned to our block group, but don't update its counters just yet. - * We want our bg to be added to the rbtree with its ->space_info set. + * Ensure the corresponding space_info object is created and + * assigned to our block group. We want our bg to be added to the rbtree + * with its ->space_info set. */ - ret = update_space_info(fs_info, cache->flags, 0, 0, 0, - &cache->space_info); - if (ret) { - btrfs_remove_free_space_cache(cache); - btrfs_put_block_group(cache); - return ret; + cache->space_info = __find_space_info(fs_info, cache->flags); + if (!cache->space_info) { + ret = create_space_info(fs_info, cache->flags, + &cache->space_info); + if (ret) { + btrfs_remove_free_space_cache(cache); + btrfs_put_block_group(cache); + return ret; + } } ret = btrfs_add_block_group_cache(fs_info, cache); @@ -10808,21 +10808,21 @@ int btrfs_init_space_info(struct btrfs_fs_info *fs_info) mixed = 1; flags = BTRFS_BLOCK_GROUP_SYSTEM; - ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info); + ret = create_space_info(fs_info, flags, &space_info); if (ret) goto out; if (mixed) { flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA; - ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info); + ret = create_space_info(fs_info, flags, &space_info); } else { flags = BTRFS_BLOCK_GROUP_METADATA; - ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info); + ret = create_space_info(fs_info, flags, &space_info); if (ret) goto out; flags = BTRFS_BLOCK_GROUP_DATA; - ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info); + ret = create_space_info(fs_info, flags, &space_info); } out: return ret; -- 2.11.0