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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 <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
hifive-unleashed-5.1
Nikolay Borisov 2018-08-15 18:26:57 +03:00 committed by David Sterba
parent df44971468
commit 9cfc8ba712
2 changed files with 5 additions and 12 deletions

View File

@ -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) &&

View File

@ -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);
}