From 9cfc8ba712be5abd476532bf672389f67e41f4ff Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Wed, 15 Aug 2018 18:26:57 +0300 Subject: [PATCH] btrfs: Remove special handling of EXTENT_BUFFER_UNMAPPED while freeing Now that the whole of btrfs code has been audited for eb reference count management it's time to remove the hunk in free_extent_buffer that essentially considered the condition "eb->ref == 2 && EXTENT_BUFFER_DUMMY" to equal "eb->ref = 1". Also remove the last location which takes an extra reference count in alloc_test_extent_buffer. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 11 ----------- fs/btrfs/tests/btrfs-tests.c | 6 +++++- 2 files changed, 5 insertions(+), 12 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 160efb201ef3..39a41e8777fc 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4893,13 +4893,6 @@ again: check_buffer_tree_ref(eb); set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags); - /* - * We will free dummy extent buffer's if they come into - * free_extent_buffer with a ref count of 2, but if we are using this we - * want the buffers to stay in memory until we're done with them, so - * bump the ref count again. - */ - atomic_inc(&eb->refs); return eb; free_eb: btrfs_release_extent_buffer(eb); @@ -5089,10 +5082,6 @@ void free_extent_buffer(struct extent_buffer *eb) } spin_lock(&eb->refs_lock); - if (atomic_read(&eb->refs) == 2 && - test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags)) - atomic_dec(&eb->refs); - if (atomic_read(&eb->refs) == 2 && test_bit(EXTENT_BUFFER_STALE, &eb->bflags) && !extent_buffer_under_io(eb) && diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c index db72b3b6209e..4cb8fcfd3ec4 100644 --- a/fs/btrfs/tests/btrfs-tests.c +++ b/fs/btrfs/tests/btrfs-tests.c @@ -174,8 +174,12 @@ void btrfs_free_dummy_root(struct btrfs_root *root) /* Will be freed by btrfs_free_fs_roots */ if (WARN_ON(test_bit(BTRFS_ROOT_IN_RADIX, &root->state))) return; - if (root->node) + if (root->node) { + /* One for allocate_extent_buffer */ free_extent_buffer(root->node); + /* One for get_exent_buffer */ + free_extent_buffer(root->node); + } kfree(root); } -- 2.30.2