Darrick and Brian have done amazing work debugging the race I created
in the folio BIO iterator. The readahead problem was deterministic,
so easy to fix.
The following changes since commit a7391ad3572431a354c927cf8896e86e50d7d0bf:
Merge tag 'iomm-fixes-v5.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu (2022-05-04 11:04:52 -0700)
are available in the Git repository at:
git://git.infradead.org/users/willy/pagecache.git tags/folio-5.18f
for you to fetch changes up to b9ff43dd27434dbd850b908e2e0e1f6e794efd9b:
mm/readahead: Fix readahead with large folios (2022-05-05 00:47:29 -0400)
----------------------------------------------------------------
Two folio fixes for 5.18:
- Fix a race when we were calling folio_next() in the BIO folio iter
without holding a reference, meaning the folio could be split or freed,
and we'd jump to the next page instead of the intended next folio.
- Fix readahead creating single-page folios instead of the intended
large folios when doing reads that are not a power of two in size.
----------------------------------------------------------------
Matthew Wilcox (Oracle) (2):
block: Do not call folio_next() on an unreferenced folio
mm/readahead: Fix readahead with large folios
include/linux/bio.h | 5 ++++-
mm/readahead.c | 15 +++++++++------
2 files changed, 13 insertions(+), 7 deletions(-)
