diff options
Diffstat (limited to 'fs')
37 files changed, 633 insertions, 296 deletions
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c index 282ca085c2f..c0861e781cd 100644 --- a/fs/btrfs/async-thread.c +++ b/fs/btrfs/async-thread.c @@ -64,6 +64,51 @@ struct btrfs_worker_thread { }; /* + * btrfs_start_workers uses kthread_run, which can block waiting for memory + * for a very long time. It will actually throttle on page writeback, + * and so it may not make progress until after our btrfs worker threads + * process all of the pending work structs in their queue + * + * This means we can't use btrfs_start_workers from inside a btrfs worker + * thread that is used as part of cleaning dirty memory, which pretty much + * involves all of the worker threads. + * + * Instead we have a helper queue who never has more than one thread + * where we scheduler thread start operations. This worker_start struct + * is used to contain the work and hold a pointer to the queue that needs + * another worker. + */ +struct worker_start { + struct btrfs_work work; + struct btrfs_workers *queue; +}; + +static void start_new_worker_func(struct btrfs_work *work) +{ + struct worker_start *start; + start = container_of(work, struct worker_start, work); + btrfs_start_workers(start->queue, 1); + kfree(start); +} + +static int start_new_worker(struct btrfs_workers *queue) +{ + struct worker_start *start; + int ret; + + start = kzalloc(sizeof(*start), GFP_NOFS); + if (!start) + return -ENOMEM; + + start->work.func = start_new_worker_func; + start->queue = queue; + ret = btrfs_queue_worker(queue->atomic_worker_start, &start->work); + if (ret) + kfree(start); + return ret; +} + +/* * helper function to move a thread onto the idle list after it * has finished some requests. */ @@ -118,11 +163,13 @@ static void check_pending_worker_creates(struct btrfs_worker_thread *worker) goto out; workers->atomic_start_pending = 0; - if (workers->num_workers >= workers->max_workers) + if (workers->num_workers + workers->num_workers_starting >= + workers->max_workers) goto out; + workers->num_workers_starting += 1; spin_unlock_irqrestore(&workers->lock, flags); - btrfs_start_workers(workers, 1); + start_new_worker(workers); return; out: @@ -390,9 +437,11 @@ int btrfs_stop_workers(struct btrfs_workers *workers) /* * simple init on struct btrfs_workers */ -void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max) +void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max, + struct btrfs_workers *async_helper) { workers->num_workers = 0; + workers->num_workers_starting = 0; INIT_LIST_HEAD(&workers->worker_list); INIT_LIST_HEAD(&workers->idle_list); INIT_LIST_HEAD(&workers->order_list); @@ -404,14 +453,15 @@ void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max) workers->name = name; workers->ordered = 0; workers->atomic_start_pending = 0; - workers->atomic_worker_start = 0; + workers->atomic_worker_start = async_helper; } /* * starts new worker threads. This does not enforce the max worker * count in case you need to temporarily go past it. */ -int btrfs_start_workers(struct btrfs_workers *workers, int num_workers) +static int __btrfs_start_workers(struct btrfs_workers *workers, + int num_workers) { struct btrfs_worker_thread *worker; int ret = 0; @@ -444,6 +494,8 @@ int btrfs_start_workers(struct btrfs_workers *workers, int num_workers) list_add_tail(&worker->worker_list, &workers->idle_list); worker->idle = 1; workers->num_workers++; + workers->num_workers_starting--; + WARN_ON(workers->num_workers_starting < 0); spin_unlock_irq(&workers->lock); } return 0; @@ -452,6 +504,14 @@ fail: return ret; } +int btrfs_start_workers(struct btrfs_workers *workers, int num_workers) +{ + spin_lock_irq(&workers->lock); + workers->num_workers_starting += num_workers; + spin_unlock_irq(&workers->lock); + return __btrfs_start_workers(workers, num_workers); +} + /* * run through the list and find a worker thread that doesn't have a lot * to do right now. This can return null if we aren't yet at the thread @@ -461,7 +521,10 @@ static struct btrfs_worker_thread *next_worker(struct btrfs_workers *workers) { struct btrfs_worker_thread *worker; struct list_head *next; - int enforce_min = workers->num_workers < workers->max_workers; + int enforce_min; + + enforce_min = (workers->num_workers + workers->num_workers_starting) < + workers->max_workers; /* * if we find an idle thread, don't move it to the end of the @@ -509,15 +572,17 @@ again: worker = next_worker(workers); if (!worker) { - if (workers->num_workers >= workers->max_workers) { + if (workers->num_workers + workers->num_workers_starting >= + workers->max_workers) { goto fallback; } else if (workers->atomic_worker_start) { workers->atomic_start_pending = 1; goto fallback; } else { + workers->num_workers_starting++; spin_unlock_irqrestore(&workers->lock, flags); /* we're below the limit, start another worker */ - btrfs_start_workers(workers, 1); + __btrfs_start_workers(workers, 1); goto again; } } diff --git a/fs/btrfs/async-thread.h b/fs/btrfs/async-thread.h index fc089b95ec1..5077746cf85 100644 --- a/fs/btrfs/async-thread.h +++ b/fs/btrfs/async-thread.h @@ -64,6 +64,8 @@ struct btrfs_workers { /* current number of running workers */ int num_workers; + int num_workers_starting; + /* max number of workers allowed. changed by btrfs_start_workers */ int max_workers; @@ -78,9 +80,10 @@ struct btrfs_workers { /* * are we allowed to sleep while starting workers or are we required - * to start them at a later time? + * to start them at a later time? If we can't sleep, this indicates + * which queue we need to use to schedule thread creation. */ - int atomic_worker_start; + struct btrfs_workers *atomic_worker_start; /* list with all the work threads. The workers on the idle thread * may be actively servicing jobs, but they haven't yet hit the @@ -109,7 +112,8 @@ struct btrfs_workers { int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work); int btrfs_start_workers(struct btrfs_workers *workers, int num_workers); int btrfs_stop_workers(struct btrfs_workers *workers); -void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max); +void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max, + struct btrfs_workers *async_starter); int btrfs_requeue_work(struct btrfs_work *work); void btrfs_set_work_high_prio(struct btrfs_work *work); #endif diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index a54d354cefc..c71abec0ab9 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -128,12 +128,14 @@ struct btrfs_inode { u64 last_unlink_trans; /* - * These two counters are for delalloc metadata reservations. We keep - * track of how many extents we've accounted for vs how many extents we - * have. + * Counters to keep track of the number of extent item's we may use due + * to delalloc and such. outstanding_extents is the number of extent + * items we think we'll end up using, and reserved_extents is the number + * of extent items we've reserved metadata for. */ - int delalloc_reserved_extents; - int delalloc_extents; + spinlock_t accounting_lock; + int reserved_extents; + int outstanding_extents; /* * ordered_data_close is set by truncate when a file that used diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index dd8ced9814c..1bb897ecdee 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -691,14 +691,17 @@ struct btrfs_space_info { struct list_head list; + /* for controlling how we free up space for allocations */ + wait_queue_head_t allocate_wait; + wait_queue_head_t flush_wait; + int allocating_chunk; + int flushing; + /* for block groups in our same type */ struct list_head block_groups; spinlock_t lock; struct rw_semaphore groups_sem; atomic_t caching_threads; - - int allocating_chunk; - wait_queue_head_t wait; }; /* @@ -907,6 +910,7 @@ struct btrfs_fs_info { * A third pool does submit_bio to avoid deadlocking with the other * two */ + struct btrfs_workers generic_worker; struct btrfs_workers workers; struct btrfs_workers delalloc_workers; struct btrfs_workers endio_workers; @@ -914,6 +918,7 @@ struct btrfs_fs_info { struct btrfs_workers endio_meta_write_workers; struct btrfs_workers endio_write_workers; struct btrfs_workers submit_workers; + struct btrfs_workers enospc_workers; /* * fixup workers take dirty pages that didn't properly go through * the cow mechanism and make them safe to write. It happens @@ -1005,6 +1010,8 @@ struct btrfs_root { atomic_t log_commit[2]; unsigned long log_transid; unsigned long log_batch; + pid_t log_start_pid; + bool log_multiple_pids; u64 objectid; u64 last_trans; @@ -2323,7 +2330,7 @@ int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode); void btrfs_orphan_cleanup(struct btrfs_root *root); int btrfs_cont_expand(struct inode *inode, loff_t size); int btrfs_invalidate_inodes(struct btrfs_root *root); -extern struct dentry_operations btrfs_dentry_operations; +extern const struct dentry_operations btrfs_dentry_operations; /* ioctl.c */ long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg); diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index af0435f79fa..100551a66c4 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1746,21 +1746,25 @@ struct btrfs_root *open_ctree(struct super_block *sb, err = -EINVAL; goto fail_iput; } -printk("thread pool is %d\n", fs_info->thread_pool_size); - /* - * we need to start all the end_io workers up front because the - * queue work function gets called at interrupt time, and so it - * cannot dynamically grow. - */ + + btrfs_init_workers(&fs_info->generic_worker, + "genwork", 1, NULL); + btrfs_init_workers(&fs_info->workers, "worker", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->delalloc_workers, "delalloc", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->submit_workers, "submit", min_t(u64, fs_devices->num_devices, - fs_info->thread_pool_size)); + fs_info->thread_pool_size), + &fs_info->generic_worker); + btrfs_init_workers(&fs_info->enospc_workers, "enospc", + fs_info->thread_pool_size, + &fs_info->generic_worker); /* a higher idle thresh on the submit workers makes it much more * likely that bios will be send down in a sane order to the @@ -1774,15 +1778,20 @@ printk("thread pool is %d\n", fs_info->thread_pool_size); fs_info->delalloc_workers.idle_thresh = 2; fs_info->delalloc_workers.ordered = 1; - btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1); + btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->endio_workers, "endio", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->endio_meta_write_workers, - "endio-meta-write", fs_info->thread_pool_size); + "endio-meta-write", fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->endio_write_workers, "endio-write", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); /* * endios are largely parallel and should have a very @@ -1794,12 +1803,8 @@ printk("thread pool is %d\n", fs_info->thread_pool_size); fs_info->endio_write_workers.idle_thresh = 2; fs_info->endio_meta_write_workers.idle_thresh = 2; - fs_info->endio_workers.atomic_worker_start = 1; - fs_info->endio_meta_workers.atomic_worker_start = 1; - fs_info->endio_write_workers.atomic_worker_start = 1; - fs_info->endio_meta_write_workers.atomic_worker_start = 1; - btrfs_start_workers(&fs_info->workers, 1); + btrfs_start_workers(&fs_info->generic_worker, 1); btrfs_start_workers(&fs_info->submit_workers, 1); btrfs_start_workers(&fs_info->delalloc_workers, 1); btrfs_start_workers(&fs_info->fixup_workers, 1); @@ -1807,6 +1812,7 @@ printk("thread pool is %d\n", fs_info->thread_pool_size); btrfs_start_workers(&fs_info->endio_meta_workers, 1); btrfs_start_workers(&fs_info->endio_meta_write_workers, 1); btrfs_start_workers(&fs_info->endio_write_workers, 1); + btrfs_start_workers(&fs_info->enospc_workers, 1); fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super); fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages, @@ -2012,6 +2018,7 @@ fail_chunk_root: free_extent_buffer(chunk_root->node); free_extent_buffer(chunk_root->commit_root); fail_sb_buffer: + btrfs_stop_workers(&fs_info->generic_worker); btrfs_stop_workers(&fs_info->fixup_workers); btrfs_stop_workers(&fs_info->delalloc_workers); btrfs_stop_workers(&fs_info->workers); @@ -2020,6 +2027,7 @@ fail_sb_buffer: btrfs_stop_workers(&fs_info->endio_meta_write_workers); btrfs_stop_workers(&fs_info->endio_write_workers); btrfs_stop_workers(&fs_info->submit_workers); + btrfs_stop_workers(&fs_info->enospc_workers); fail_iput: invalidate_inode_pages2(fs_info->btree_inode->i_mapping); iput(fs_info->btree_inode); @@ -2437,6 +2445,7 @@ int close_ctree(struct btrfs_root *root) iput(fs_info->btree_inode); + btrfs_stop_workers(&fs_info->generic_worker); btrfs_stop_workers(&fs_info->fixup_workers); btrfs_stop_workers(&fs_info->delalloc_workers); btrfs_stop_workers(&fs_info->workers); @@ -2445,6 +2454,7 @@ int close_ctree(struct btrfs_root *root) btrfs_stop_workers(&fs_info->endio_meta_write_workers); btrfs_stop_workers(&fs_info->endio_write_workers); btrfs_stop_workers(&fs_info->submit_workers); + btrfs_stop_workers(&fs_info->enospc_workers); btrfs_close_devices(fs_info->fs_devices); btrfs_mapping_tree_free(&fs_info->mapping_tree); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 359a754c782..d0c4d584efa 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2824,14 +2824,17 @@ int btrfs_unreserve_metadata_for_delalloc(struct btrfs_root *root, num_items); spin_lock(&meta_sinfo->lock); - if (BTRFS_I(inode)->delalloc_reserved_extents <= - BTRFS_I(inode)->delalloc_extents) { + spin_lock(&BTRFS_I(inode)->accounting_lock); + if (BTRFS_I(inode)->reserved_extents <= + BTRFS_I(inode)->outstanding_extents) { + spin_unlock(&BTRFS_I(inode)->accounting_lock); spin_unlock(&meta_sinfo->lock); return 0; } + spin_unlock(&BTRFS_I(inode)->accounting_lock); - BTRFS_I(inode)->delalloc_reserved_extents--; - BUG_ON(BTRFS_I(inode)->delalloc_reserved_extents < 0); + BTRFS_I(inode)->reserved_extents--; + BUG_ON(BTRFS_I(inode)->reserved_extents < 0); if (meta_sinfo->bytes_delalloc < num_bytes) { bug = true; @@ -2864,6 +2867,107 @@ static void check_force_delalloc(struct btrfs_space_info *meta_sinfo) meta_sinfo->force_delalloc = 0; } +struct async_flush { + struct btrfs_root *root; + struct btrfs_space_info *info; + struct btrfs_work work; +}; + +static noinline void flush_delalloc_async(struct btrfs_work *work) +{ + struct async_flush *async; + struct btrfs_root *root; + struct btrfs_space_info *info; + + async = container_of(work, struct async_flush, work); + root = async->root; + info = async->info; + + btrfs_start_delalloc_inodes(root); + wake_up(&info->flush_wait); + btrfs_wait_ordered_extents(root, 0); + + spin_lock(&info->lock); + info->flushing = 0; + spin_unlock(&info->lock); + wake_up(&info->flush_wait); + + kfree(async); +} + +static void wait_on_flush(struct btrfs_space_info *info) +{ + DEFINE_WAIT(wait); + u64 used; + + while (1) { + prepare_to_wait(&info->flush_wait, &wait, + TASK_UNINTERRUPTIBLE); + spin_lock(&info->lock); + if (!info->flushing) { + spin_unlock(&info->lock); + break; + } + + used = info->bytes_used + info->bytes_reserved + + info->bytes_pinned + info->bytes_readonly + + info->bytes_super + info->bytes_root + + info->bytes_may_use + info->bytes_delalloc; + if (used < info->total_bytes) { + spin_unlock(&info->lock); + break; + } + spin_unlock(&info->lock); + schedule(); + } + finish_wait(&info->flush_wait, &wait); +} + +static void flush_delalloc(struct btrfs_root *root, + struct btrfs_space_info *info) +{ + struct async_flush *async; + bool wait = false; + + spin_lock(&info->lock); + + if (!info->flushing) { + info->flushing = 1; + init_waitqueue_head(&info->flush_wait); + } else { + wait = true; + } + + spin_unlock(&info->lock); + + if (wait) { + wait_on_flush(info); + return; + } + + async = kzalloc(sizeof(*async), GFP_NOFS); + if (!async) + goto flush; + + async->root = root; + async->info = info; + async->work.func = flush_delalloc_async; + + btrfs_queue_worker(&root->fs_info->enospc_workers, + &async->work); + wait_on_flush(info); + return; + +flush: + btrfs_start_delalloc_inodes(root); + btrfs_wait_ordered_extents(root, 0); + + spin_lock(&info->lock); + info->flushing = 0; + spin_unlock(&info->lock); + wake_up(&info->flush_wait); +} + static int maybe_allocate_chunk(struct btrfs_root *root, struct btrfs_space_info *info) { @@ -2894,7 +2998,7 @@ static int maybe_allocate_chunk(struct btrfs_root *root, if (!info->allocating_chunk) { info->force_alloc = 1; info->allocating_chunk = 1; - init_waitqueue_head(&info->wait); + init_waitqueue_head(&info->allocate_wait); } else { wait = true; } @@ -2902,7 +3006,7 @@ static int maybe_allocate_chunk(struct btrfs_root *root, spin_unlock(&info->lock); if (wait) { - wait_event(info->wait, + wait_event(info->allocate_wait, !info->allocating_chunk); return 1; } @@ -2923,7 +3027,7 @@ out: spin_lock(&info->lock); info->allocating_chunk = 0; spin_unlock(&info->lock); - wake_up(&info->wait); + wake_up(&info->allocate_wait); if (ret) return 0; @@ -2981,21 +3085,20 @@ again: filemap_flush(inode->i_mapping); goto again; } else if (flushed == 3) { - btrfs_start_delalloc_inodes(root); - btrfs_wait_ordered_extents(root, 0); + flush_delalloc(root, meta_sinfo); goto again; } spin_lock(&meta_sinfo->lock); meta_sinfo->bytes_delalloc -= num_bytes; spin_unlock(&meta_sinfo->lock); printk(KERN_ERR "enospc, has %d, reserved %d\n", - BTRFS_I(inode)->delalloc_extents, - BTRFS_I(inode)->delalloc_reserved_extents); + BTRFS_I(inode)->outstanding_extents, + BTRFS_I(inode)->reserved_extents); dump_space_info(meta_sinfo, 0, 0); return -ENOSPC; } - BTRFS_I(inode)->delalloc_reserved_extents++; + BTRFS_I(inode)->reserved_extents++; check_force_delalloc(meta_sinfo); spin_unlock(&meta_sinfo->lock); @@ -3094,8 +3197,7 @@ again: } if (retries == 2) { - btrfs_start_delalloc_inodes(root); - btrfs_wait_ordered_extents(root, 0); + flush_delalloc(root, meta_sinfo); goto again; } spin_lock(&meta_sinfo->lock); @@ -4029,6 +4131,7 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans, int loop = 0; bool found_uncached_bg = false; bool failed_cluster_refill = false; + bool failed_alloc = false; WARN_ON(num_bytes < root->sectorsize); btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); @@ -4233,14 +4336,23 @@ refill_cluster: offset = btrfs_find_space_for_alloc(block_group, search_start, num_bytes, empty_size); - if (!offset && (cached || (!cached && - loop == LOOP_CACHING_NOWAIT))) { - goto loop; - } else if (!offset && (!cached && - loop > LOOP_CACHING_NOWAIT)) { + /* + * If we didn't find a chunk, and we haven't failed on this + * block group before, and this block group is in the middle of + * caching and we are ok with waiting, then go ahead and wait + * for progress to be made, and set failed_alloc to true. + * + * If failed_alloc is true then we've already waited on this + * block group once and should move on to the next block group. + */ + if (!offset && !failed_alloc && !cached && + loop > LOOP_CACHING_NOWAIT) { wait_block_group_cache_progress(block_group, - num_bytes + empty_size); + num_bytes + empty_size); + failed_alloc = true; goto have_block_group; + } else if (!offset) { + goto loop; } checks: search_start = stripe_align(root, offset); @@ -4288,6 +4400,7 @@ checks: break; loop: failed_cluster_refill = false; + failed_alloc = false; btrfs_put_block_group(block_group); } up_read(&space_info->groups_sem); @@ -4799,6 +4912,7 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans, u64 bytenr; u64 generation; u64 refs; + u64 flags; u64 last = 0; u32 nritems; u32 blocksize; @@ -4836,15 +4950,19 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans, generation <= root->root_key.offset) continue; + /* We don't lock the tree block, it's OK to be racy here */ + ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize, + &refs, &flags); + BUG_ON(ret); + BUG_ON(refs == 0); + if (wc->stage == DROP_REFERENCE) { - ret = btrfs_lookup_extent_info(trans, root, - bytenr, blocksize, - &refs, NULL); - BUG_ON(ret); - BUG_ON(refs == 0); if (refs == 1) goto reada; + if (wc->level == 1 && + (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) + continue; if (!wc->update_ref || generation <= root->root_key.offset) continue; @@ -4853,6 +4971,10 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans, &wc->update_progress); if (ret < 0) continue; + } else { + if (wc->level == 1 && + (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) + continue; } reada: ret = readahead_tree_block(root, bytenr, blocksize, @@ -4876,7 +4998,7 @@ reada: static noinline int walk_down_proc(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, - struct walk_control *wc) + struct walk_control *wc, int lookup_info) { int level = wc->level; struct extent_buffer *eb = path->nodes[level]; @@ -4891,8 +5013,9 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans, * when reference count of tree block is 1, it won't increase * again. once full backref flag is set, we never clear it. */ - if ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) || - (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag))) { + if (lookup_info && + ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) || + (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) { BUG_ON(!path->locks[level]); ret = btrfs_lookup_extent_info(trans, root, eb->start, eb->len, @@ -4953,7 +5076,7 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans, static noinline int do_walk_down(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, - struct walk_control *wc) + struct walk_control *wc, int *lookup_info) { u64 bytenr; u64 generation; @@ -4973,8 +5096,10 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, * for the subtree */ if (wc->stage == UPDATE_BACKREF && - generation <= root->root_key.offset) + generation <= root->root_key.offset) { + *lookup_info = 1; return 1; + } bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]); blocksize = btrfs_level_size(root, level - 1); @@ -4987,14 +5112,19 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, btrfs_tree_lock(next); btrfs_set_lock_blocking(next); - if (wc->stage == DROP_REFERENCE) { - ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize, - &wc->refs[level - 1], - &wc->flags[level - 1]); - BUG_ON(ret); - BUG_ON(wc->refs[level - 1] == 0); + ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize, + &wc->refs[level - 1], + &wc->flags[level - 1]); + BUG_ON(ret); + BUG_ON(wc->refs[level - 1] == 0); + *lookup_info = 0; + if (wc->stage == DROP_REFERENCE) { if (wc->refs[level - 1] > 1) { + if (level == 1 && + (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF)) + goto skip; + if (!wc->update_ref || generation <= root->root_key.offset) goto skip; @@ -5008,12 +5138,17 @@ static n |