[RFC PATCH 0/2] enable sector size > PAGE_SIZE for scsi

[sw.prabhu6@gmail.com]

From: Swarna Prabhu <sw.prabhu6@gmail.com>

Hi All,

Now that block layer can support block size > PAGE_SIZE, enable the
same for scsi devices. There was one issue with write_same16 and
write_same10 command, which is fixed as a part of the series.

Testing:
  1. Test suite: xfs and generic from fstest + QEMU emulated block
    device(scsi and nvme)
  - fstest Config for patched xfs 16k block size [xfs_reflink_16k_scsi]
    TEST_DEV=/dev/sda
    SCRATCH_DEV_POOL="/dev/sdb"
    MKFS_OPTIONS='-f -m reflink=1,rmapbt=1, -i sparse=1, -b size=16384, 
    -s size=16384'
  - Generic test results 
    Baseline: 6.18-rc5 kernel + nvme 16k logical block size
    Patched: 6.18-rc5 kernel + scsi 16k logical block size
    6 failures seen on generic tests and the same seen on baseline 
    No regressions 
  - XFS tests results 
    Baseline: 6.18-rc6 kernel + nvme16k logical block size
    Patched: 6.18-rc6 kernel + sci 16k logical block size
    198 failures seen on patched and baseline
    No regressions 
  - Tests similar to above was run on 32k logical block size
    No regressions seen on xfs tests. 
    Generic/778 (add sudden shutdown tests for multi block atomic writes
    )test is failing on scsi 32k block size due to atomic write taking
    too long to start, but is passing on the nvme 32k block size setup. 
    Since sysfs shows atomic write granularity not enforced for scsi device
    it seems that XFS issues atomic writes slower. Upon increasing the 
    wait timeout from 10s to 40s for the first atomic write in 
    'start_atomic_write_and_shutdown' generic/778 seems to pass for 
    32k scsi sector size.  

 2. blktests: scsi and block layer sub tests 
    Baseline: tests with scsi 4k block size 
    Patched:  tests with patched kernel + 16k scsi block size
  - scsi tests - no regressions.
  - block tests - Disabled block/010 and block/011 
    Hard to reproduce(sporadic) kernel hang seen while running 
    block layer tests ie at block/003 due to fio task being blocked
    by a mutex held by udev event. Not seen while running it
    individually. 
    Rootcause - block/001 stress the scsi debug devices by adding,
    tearing, removing the devices in parallel that triggers udevs.
    This races with fio task triggered by block/003. 
    Added udevadm settle and small delay between block/001 and 
    block/003 fixes this and using this as a temporary fix, while
    we continue to evaluate. Note: block/002 being skipped.

Swarna Prabhu (2):
  scsi: fix write_same16 and write_same10 for sector size > PAGE_SIZE
  scsi: enable sector_size > PAGE_SIZE

 drivers/scsi/scsi_debug.c |  9 ++-------
 drivers/scsi/sd.c         | 19 +++++++++++++------
 2 files changed, 15 insertions(+), 13 deletions(-)

-- 
2.51.0