From ceb21a8db48559fd0809e03c4df9eb37743d9170 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 24 Aug 2018 19:35:04 +0200 Subject: [PATCH] btrfs: reada: reorder dev-replace locks before radix tree preload The device-replace read lock is going to use rw semaphore in followup commits. The semaphore might sleep which is not possible in the radix tree preload section. The lock nesting is now: * device replace * radix tree preload * readahead spinlock Signed-off-by: David Sterba --- fs/btrfs/reada.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c index dec14b739b10..6f81f3e88b6d 100644 --- a/fs/btrfs/reada.c +++ b/fs/btrfs/reada.c @@ -376,26 +376,28 @@ static struct reada_extent *reada_find_extent(struct btrfs_fs_info *fs_info, goto error; } + /* Insert extent in reada tree + all per-device trees, all or nothing */ + btrfs_dev_replace_read_lock(&fs_info->dev_replace); ret = radix_tree_preload(GFP_KERNEL); - if (ret) + if (ret) { + btrfs_dev_replace_read_unlock(&fs_info->dev_replace); goto error; + } - /* insert extent in reada_tree + all per-device trees, all or nothing */ - btrfs_dev_replace_read_lock(&fs_info->dev_replace); spin_lock(&fs_info->reada_lock); ret = radix_tree_insert(&fs_info->reada_tree, index, re); if (ret == -EEXIST) { re_exist = radix_tree_lookup(&fs_info->reada_tree, index); re_exist->refcnt++; spin_unlock(&fs_info->reada_lock); - btrfs_dev_replace_read_unlock(&fs_info->dev_replace); radix_tree_preload_end(); + btrfs_dev_replace_read_unlock(&fs_info->dev_replace); goto error; } if (ret) { spin_unlock(&fs_info->reada_lock); - btrfs_dev_replace_read_unlock(&fs_info->dev_replace); radix_tree_preload_end(); + btrfs_dev_replace_read_unlock(&fs_info->dev_replace); goto error; } radix_tree_preload_end(); -- 2.30.2