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btrfs: migrate eb_bitmap_offset() to folio interfaces

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[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:
  <TASK>
  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
  </TASK>

[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 <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2023-12-12 15:54:09 +10:30 committed by David Sterba
parent a700ca5ec4
commit f4521b01c5
1 changed files with 10 additions and 12 deletions
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22
fs/btrfs/extent_io.c
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@ -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)));
}