From 7d82240c457fc15abdf7dedf15104cea774b005b Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 1 Apr 2025 18:20:28 +1030 Subject: [PATCH] btrfs: fix the ASSERT() inside GET_SUBPAGE_BITMAP() After enabling large data folios for tests, I hit the ASSERT() inside GET_SUBPAGE_BITMAP() where blocks_per_folio matches BITS_PER_LONG. The ASSERT() itself is only based on the original subpage fs block size, where we have at most 16 blocks per page, thus "ASSERT(blocks_per_folio < BITS_PER_LONG)". However the experimental large data folio support will set the max folio order according to the BITS_PER_LONG, so we can have a case where a large folio contains exactly BITS_PER_LONG blocks. So the ASSERT() is too strict, change it to "ASSERT(blocks_per_folio <= BITS_PER_LONG)" to avoid the false alert. Reviewed-by: Filipe Manana Reviewed-by: Sweet Tea Dorminy Reviewed-by: Boris Burkov Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/subpage.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c index bd252c78a261..c0a0b8b063d0 100644 --- a/fs/btrfs/subpage.c +++ b/fs/btrfs/subpage.c @@ -666,7 +666,7 @@ IMPLEMENT_BTRFS_PAGE_OPS(checked, folio_set_checked, folio_clear_checked, btrfs_blocks_per_folio(fs_info, folio); \ const struct btrfs_subpage *subpage = folio_get_private(folio); \ \ - ASSERT(blocks_per_folio < BITS_PER_LONG); \ + ASSERT(blocks_per_folio <= BITS_PER_LONG); \ *dst = bitmap_read(subpage->bitmaps, \ blocks_per_folio * btrfs_bitmap_nr_##name, \ blocks_per_folio); \