It is unsafe to call folio_next() on a folio unless you hold a reference
on it that prevents it from being split or freed.  After returning
from the iterator, iomap calls folio_end_writeback() which may drop
the last reference to the page, or allow the page to be split.  If that
happens, the iterator will not advance far enough through the bio_vec,
leading to assertion failures like the BUG() in folio_end_writeback()
that checks we're not trying to end writeback on a page not currently
under writeback.  Other assertion failures were also seen, but they're
all explained by this one bug.

Fix the bug by remembering where the next folio starts before returning
from the iterator.  There are other ways of fixing this bug, but this
seems the simplest.

Reported-by: Darrick J. Wong <djwong@kernel.org>
Tested-by: Darrick J. Wong <djwong@kernel.org>
Reported-by: Brian Foster <bfoster@redhat.com>
Tested-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Pull SCSI updates from James Bottomley:
 "This series consists of the usual driver updates (qla2xxx, pm8001,
  libsas, smartpqi, scsi_debug, lpfc, iscsi, mpi3mr) plus minor updates
  and bug fixes.

  The high blast radius core update is the removal of write same, which
  affects block and several non-SCSI devices. The other big change,
  which is more local, is the removal of the SCSI pointer"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (281 commits)
  scsi: scsi_ioctl: Drop needless assignment in sg_io()
  scsi: bsg: Drop needless assignment in scsi_bsg_sg_io_fn()
  scsi: lpfc: Copyright updates for 14.2.0.0 patches
  scsi: lpfc: Update lpfc version to 14.2.0.0
  scsi: lpfc: SLI path split: Refactor BSG paths
  scsi: lpfc: SLI path split: Refactor Abort paths
  scsi: lpfc: SLI path split: Refactor SCSI paths
  scsi: lpfc: SLI path split: Refactor CT paths
  scsi: lpfc: SLI path split: Refactor misc ELS paths
  scsi: lpfc: SLI path split: Refactor VMID paths
  scsi: lpfc: SLI path split: Refactor FDISC paths
  scsi: lpfc: SLI path split: Refactor LS_RJT paths
  scsi: lpfc: SLI path split: Refactor LS_ACC paths
  scsi: lpfc: SLI path split: Refactor the RSCN/SCR/RDF/EDC/FARPR paths
  scsi: lpfc: SLI path split: Refactor PLOGI/PRLI/ADISC/LOGO paths
  scsi: lpfc: SLI path split: Refactor base ELS paths and the FLOGI path
  scsi: lpfc: SLI path split: Introduce lpfc_prep_wqe
  scsi: lpfc: SLI path split: Refactor fast and slow paths to native SLI4
  scsi: lpfc: SLI path split: Refactor lpfc_iocbq
  scsi: lpfc: Use kcalloc()
  ...

All callers are gone, so remove this wrapper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220304180105.409765-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

No more users of REQ_OP_WRITE_SAME or drivers implementing it are left,
so remove the infrastructure.

[mkp: fold in and tweak sysfs reporting fix]

Link: https://lore.kernel.org/r/20220209082828.2629273-8-hch@lst.de
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Pass a block_device to bio_clone_fast and __bio_clone_fast and give
the functions more suitable names.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

__bio_clone_fast should also clone integrity and crypto data, as a clone
without those is incomplete.  Right now the only caller that can actually
support crypto and integrity data (dm) does it manually for the one
callchain that supports these, but we better do it properly in the core.

Note that all callers except for the above mentioned one also don't need
to handle failure at all, given that the integrity and crypto clones are
based on mempool allocations that won't fail for sleeping allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pass the block_device that we plan to use this bio for and the
operation to bio_reset to optimize the assigment.  A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-20-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pass the block_device that we plan to use this bio for and the
operation to bio_init to optimize the assignment.  A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-19-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment.  NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc_kiocb to optimize the assigment.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-17-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>