public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-04-13 09:59:31 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

btrfs: subpage: dump the involved bitmap when ASSERT() failed

Browse source 
For btrfs_folio_assert_not_dirty() and btrfs_folio_set_lock(), we call
bitmap_test_range_all_zero() to ensure the involved range has no
dirty/lock bit already set.

However with my recent enhanced delalloc range error handling, I was
hitting the ASSERT() inside btrfs_folio_set_lock(), and it turns out
that some error handling path is not properly updating the folio flags.

So add some extra dumping for the ASSERTs to dump the involved bitmap
to help debug.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2024-12-12 16:44:01 +10:30 • committed by David Sterba
parent 396294d1af
commit 61d730731b
1 changed files with 30 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

41
fs/btrfs/subpage.c
View file

@ -635,6 +635,28 @@ IMPLEMENT_BTRFS_PAGE_OPS(ordered, folio_set_ordered, folio_clear_ordered,
IMPLEMENT_BTRFS_PAGE_OPS(checked, folio_set_checked, folio_clear_checked,
folio_test_checked);
#define GET_SUBPAGE_BITMAP(subpage, fs_info, name, dst) \
{ \
const int sectors_per_page = fs_info->sectors_per_page; \
\
ASSERT(sectors_per_page < BITS_PER_LONG); \
*dst = bitmap_read(subpage->bitmaps, \
sectors_per_page * btrfs_bitmap_nr_##name, \
sectors_per_page); \
}
#define SUBPAGE_DUMP_BITMAP(fs_info, folio, name, start, len) \
{ \
const struct btrfs_subpage *subpage = folio_get_private(folio); \
unsigned long bitmap; \
\
GET_SUBPAGE_BITMAP(subpage, fs_info, name, &bitmap); \
btrfs_warn(fs_info, \
"dumpping bitmap start=%llu len=%u folio=%llu " #name "_bitmap=%*pbl", \
start, len, folio_pos(folio), \
fs_info->sectors_per_page, &bitmap); \
}
/*
* Make sure not only the page dirty bit is cleared, but also subpage dirty bit
* is cleared.
@ -660,6 +682,10 @@ void btrfs_folio_assert_not_dirty(const struct btrfs_fs_info *fs_info,
subpage = folio_get_private(folio);
ASSERT(subpage);
spin_lock_irqsave(&subpage->lock, flags);
if (unlikely(!bitmap_test_range_all_zero(subpage->bitmaps, start_bit, nbits))) {
SUBPAGE_DUMP_BITMAP(fs_info, folio, dirty, start, len);
ASSERT(bitmap_test_range_all_zero(subpage->bitmaps, start_bit, nbits));
}
ASSERT(bitmap_test_range_all_zero(subpage->bitmaps, start_bit, nbits));
spin_unlock_irqrestore(&subpage->lock, flags);
}
@ -689,23 +715,16 @@ void btrfs_folio_set_lock(const struct btrfs_fs_info *fs_info,
nbits = len >> fs_info->sectorsize_bits;
spin_lock_irqsave(&subpage->lock, flags);
/* Target range should not yet be locked. */
ASSERT(bitmap_test_range_all_zero(subpage->bitmaps, start_bit, nbits));
if (unlikely(!bitmap_test_range_all_zero(subpage->bitmaps, start_bit, nbits))) {
SUBPAGE_DUMP_BITMAP(fs_info, folio, locked, start, len);
ASSERT(bitmap_test_range_all_zero(subpage->bitmaps, start_bit, nbits));
}
bitmap_set(subpage->bitmaps, start_bit, nbits);
ret = atomic_add_return(nbits, &subpage->nr_locked);
ASSERT(ret <= fs_info->sectors_per_page);
spin_unlock_irqrestore(&subpage->lock, flags);
}
#define GET_SUBPAGE_BITMAP(subpage, fs_info, name, dst) \
{ \
const int sectors_per_page = fs_info->sectors_per_page; \
\
ASSERT(sectors_per_page < BITS_PER_LONG); \
*dst = bitmap_read(subpage->bitmaps, \
sectors_per_page * btrfs_bitmap_nr_##name, \
sectors_per_page); \
}
void __cold btrfs_subpage_dump_bitmap(const struct btrfs_fs_info *fs_info,
struct folio *folio, u64 start, u32 len)
{