mtdblock / mtdblock_ro set part_bits to 0 and thus nevever scanned
partitions.  Restore that behavior by setting the GENHD_FL_NO_PART flag.

Fixes: 1ebe2e5f9d68e94c ("block: remove GENHD_FL_EXT_DEVT")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20211206070409.2836165-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The block layer already performs this check, no need to duplicate it in
the driver.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20211126121802.2090656-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This function is trivial, and flush_dcache_page is always defined, so
just open code it in the 2.5 callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20211117061404.331732-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.

Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211015233028.2167651-10-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull MTD updates from Miquel Raynal:
 "MTD changes:
   - blkdevs:
       - Simplify the refcounting in blktrans_{open, release}
       - Simplify blktrans_getgeo
       - Remove blktrans_ref_mutex
       - Simplify blktrans_dev_get
       - Use lockdep_assert_held
       - Don't hold del_mtd_blktrans_dev in blktrans_{open, release}
   - ftl:
       - Don't cast away the type when calling add_mtd_blktrans_dev
       - Don't cast away the type when calling add_mtd_blktrans_dev
       - Use container_of() rather than cast
       - Fix use-after-free
       - Add discard support
       - Allow use of MTD_RAM for testing purposes
   - concat:
       - Check _read, _write callbacks existence before assignment
       - Judge callback existence based on the master
   - maps:
       - Maps: remove dead MTD map driver for PMC-Sierra MSP boards
   - mtdblock:
       - Warn if added for a NAND device
       - Add comment about UBI block devices
       - Update old JFFS2 mention in Kconfig
   - partitions:
       - Redboot: convert to YAML

  NAND core changes:
   - Repair Miquel Raynal's email address in MAINTAINERS
   - Fix a couple of spelling mistakes in Kconfig
   - bbt: Skip bad blocks when searching for the BBT in NAND
   - Remove never changed ret variable

  Raw NAND changes:
   - cafe: Fix a resource leak in the error handling path of 'cafe_nand_probe()'
   - intel: Fix error handling in probe
   - omap: Fix kernel doc warning on 'calcuate' typo
   - gpmc: Fix the ECC bytes vs. OOB bytes equation

  SPI-NAND core changes:
   - Properly fill the OOB area.
   - Fix comment

  SPI-NAND drivers changes:
   - macronix: Add Quad support for serial NAND flash"

* tag 'mtd/for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: (30 commits)
  mtd: rawnand: cafe: Fix a resource leak in the error handling path of 'cafe_nand_probe()'
  mtd_blkdevs: simplify the refcounting in blktrans_{open, release}
  mtd_blkdevs: simplify blktrans_getgeo
  mtd_blkdevs: remove blktrans_ref_mutex
  mtd_blkdevs: simplify blktrans_dev_get
  mtd/rfd_ftl: don't cast away the type when calling add_mtd_blktrans_dev
  mtd/ftl: don't cast away the type when calling add_mtd_blktrans_dev
  mtd_blkdevs: use lockdep_assert_held
  mtd_blkdevs: don't hold del_mtd_blktrans_dev in blktrans_{open, release}
  mtd: rawnand: intel: Fix error handling in probe
  mtd: mtdconcat: Check _read, _write callbacks existence before assignment
  mtd: mtdconcat: Judge callback existence based on the master
  mtd: maps: remove dead MTD map driver for PMC-Sierra MSP boards
  mtd: rfd_ftl: use container_of() rather than cast
  mtd: rfd_ftl: fix use-after-free
  mtd: rfd_ftl: add discard support
  mtd: rfd_ftl: allow use of MTD_RAM for testing purposes
  mtdblock: Warn if added for a NAND device
  mtd: spinand: macronix: Add Quad support for serial NAND flash
  mtdblock: Add comment about UBI block devices
  ...

Always grab a reference to the mtd_blktrans_dev in ->open instead of
just on the first open, and do away with the additional temporary
references in ->open and ->release.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210823073359.705281-9-hch@lst.de

No need to grab a mtd_blktrans_dev given that ->open already holds one
and ->getgeo can only be called on an open disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210823073359.705281-8-hch@lst.de

blktrans_ref_mutex is not actually needed.  The kref is serialized
internally, and devnum assignment in add_mtd_blktrans_dev happens before
the disk is added and thus any of the block_device_operations methods
otherwise using it are called.  It  is also already serialized by the
global mtd_table_mutex.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210823073359.705281-7-hch@lst.de

->private_data is set before the disk is added and never cleared, so don't
bother trying to handle a NULL pointer there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210823073359.705281-6-hch@lst.de

Use lockdep_assert_held to ensure mtd_table_mutex is held instead of
mutex_trylock games.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210823073359.705281-3-hch@lst.de