From 8326b72345599f84d10eb7cd632468244861a3b1 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 dec14b739b101..6f81f3e88b6d0 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(); -- 2.39.5