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| author | Kent Overstreet <kent.overstreet@gmail.com> | 2022-03-28 12:31:22 -0400 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-22 17:09:28 -0400 |
| commit | 30690c441a6b481aadb0284d1b9bf487f8d28bfc (patch) | |
| tree | a28eb307741e99bb57302da52d43374107d7b2f7 /fs/bcachefs/util.h | |
| parent | fd1e9c69959ec2dd0946f3d2285548c87f9d6ea3 (diff) | |
| download | lwn-30690c441a6b481aadb0284d1b9bf487f8d28bfc.tar.gz lwn-30690c441a6b481aadb0284d1b9bf487f8d28bfc.zip | |
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 <kent.overstreet@gmail.com>
Diffstat (limited to 'fs/bcachefs/util.h')
| -rw-r--r-- | fs/bcachefs/util.h | 8 |
1 files changed, 5 insertions, 3 deletions
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) \ |