From f4521b01c5246b921debc6db6f112f89f94cc61b Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 12 Dec 2023 15:54:09 +1030 Subject: [PATCH] btrfs: migrate eb_bitmap_offset() to folio interfaces [BUG] Test case btrfs/002 would fail if larger folios are enabled for metadata: assertion failed: folio, in fs/btrfs/extent_io.c:4358 ------------[ cut here ]------------ kernel BUG at fs/btrfs/extent_io.c:4358! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 30916 Comm: fsstress Tainted: G OE 6.7.0-rc3-custom+ #128 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 2/2/2022 RIP: 0010:assert_eb_folio_uptodate+0x98/0xe0 [btrfs] Call Trace: extent_buffer_test_bit+0x3c/0x70 [btrfs] free_space_test_bit+0xcd/0x140 [btrfs] modify_free_space_bitmap+0x27a/0x430 [btrfs] add_to_free_space_tree+0x8d/0x160 [btrfs] __btrfs_free_extent.isra.0+0xef1/0x13c0 [btrfs] __btrfs_run_delayed_refs+0x786/0x13c0 [btrfs] btrfs_run_delayed_refs+0x33/0x120 [btrfs] btrfs_commit_transaction+0xa2/0x1350 [btrfs] iterate_supers+0x77/0xe0 ksys_sync+0x60/0xa0 __do_sys_sync+0xa/0x20 do_syscall_64+0x3f/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 [CAUSE] The function extent_buffer_test_bit() is not folio compatible. It still assumes the old fixed page size, when an extent buffer with large folio passed in, only eb->folios[0] is populated. Then if the target bit range falls in the 2nd page of the folio, then we would check eb->folios[1], and trigger the ASSERT(). [FIX] Just migrate eb_bitmap_offset() to folio interfaces, using the folio_size() to replace PAGE_SIZE. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 423861e5e8f5..a0ffd41c5cc1 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4459,22 +4459,22 @@ void copy_extent_buffer(const struct extent_buffer *dst, } /* - * Calculate the page and offset of the byte containing the given bit number. + * Calculate the folio and offset of the byte containing the given bit number. * * @eb: the extent buffer * @start: offset of the bitmap item in the extent buffer * @nr: bit number - * @page_index: return index of the page in the extent buffer that contains + * @folio_index: return index of the folio in the extent buffer that contains * the given bit number - * @page_offset: return offset into the page given by page_index + * @folio_offset: return offset into the folio given by folio_index * * This helper hides the ugliness of finding the byte in an extent buffer which * contains a given bit. */ static inline void eb_bitmap_offset(const struct extent_buffer *eb, unsigned long start, unsigned long nr, - unsigned long *page_index, - size_t *page_offset) + unsigned long *folio_index, + size_t *folio_offset) { size_t byte_offset = BIT_BYTE(nr); size_t offset; @@ -4484,10 +4484,10 @@ static inline void eb_bitmap_offset(const struct extent_buffer *eb, * the bitmap item in the extent buffer + the offset of the byte in the * bitmap item. */ - offset = start + offset_in_page(eb->start) + byte_offset; + offset = start + offset_in_folio(eb->folios[0], eb->start) + byte_offset; - *page_index = offset >> PAGE_SHIFT; - *page_offset = offset_in_page(offset); + *folio_index = offset >> folio_shift(eb->folios[0]); + *folio_offset = offset_in_folio(eb->folios[0], offset); } /* @@ -4500,15 +4500,13 @@ static inline void eb_bitmap_offset(const struct extent_buffer *eb, int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start, unsigned long nr) { - u8 *kaddr; - struct page *page; unsigned long i; size_t offset; + u8 *kaddr; eb_bitmap_offset(eb, start, nr, &i, &offset); - page = folio_page(eb->folios[i], 0); assert_eb_folio_uptodate(eb, i); - kaddr = page_address(page); + kaddr = folio_address(eb->folios[i]); return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1))); }