From 30690c441a6b481aadb0284d1b9bf487f8d28bfc Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Mon, 28 Mar 2022 12:31:22 -0400 Subject: bcachefs: Heap code fix When deleting an entry from a heap that was at entry h->used - 1, we'd end up calling heap_sift() on an entry outside the heap - the entry we just removed - which would end up re-adding it to the heap and deleting something we didn't want to delete. Oops... Signed-off-by: Kent Overstreet --- fs/bcachefs/util.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'fs/bcachefs/util.h') diff --git a/fs/bcachefs/util.h b/fs/bcachefs/util.h index f2df4d7fbec9..fd776fb281b7 100644 --- a/fs/bcachefs/util.h +++ b/fs/bcachefs/util.h @@ -210,9 +210,11 @@ do { \ \ BUG_ON(_i >= (h)->used); \ (h)->used--; \ - heap_swap(h, _i, (h)->used, set_backpointer); \ - heap_sift_up(h, _i, cmp, set_backpointer); \ - heap_sift_down(h, _i, cmp, set_backpointer); \ + if ((_i) < (h)->used) { \ + heap_swap(h, _i, (h)->used, set_backpointer); \ + heap_sift_up(h, _i, cmp, set_backpointer); \ + heap_sift_down(h, _i, cmp, set_backpointer); \ + } \ } while (0) #define heap_pop(h, d, cmp, set_backpointer) \ -- cgit v1.2.3