1. 03 Dec, 2009 1 commit
    • Martin K. Petersen's avatar
      block: Allow devices to indicate whether discarded blocks are zeroed · 98262f27
      Martin K. Petersen authored
      The discard ioctl is used by mkfs utilities to clear a block device
      prior to putting metadata down.  However, not all devices return zeroed
      blocks after a discard.  Some drives return stale data, potentially
      containing old superblocks.  It is therefore important to know whether
      discarded blocks are properly zeroed.
      
      Both ATA and SCSI drives have configuration bits that indicate whether
      zeroes are returned after a discard operation.  Implement a block level
      interface that allows this information to be bubbled up the stack and
      queried via a new block device ioctl.
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      98262f27
  2. 03 Oct, 2009 1 commit
  3. 22 May, 2009 2 commits
  4. 16 Apr, 2009 1 commit
  5. 29 Dec, 2008 1 commit
  6. 04 Dec, 2008 2 commits
  7. 23 Oct, 2008 1 commit
  8. 21 Oct, 2008 5 commits
  9. 09 Oct, 2008 1 commit
  10. 13 May, 2008 1 commit
  11. 17 Apr, 2008 1 commit
    • Bartlomiej Zolnierkiewicz's avatar
      ide: remove broken/dangerous HDIO_[UNREGISTER,SCAN]_HWIF ioctls (take 3) · 93de00fd
      Bartlomiej Zolnierkiewicz authored
      hdparm explicitely marks HDIO_[UNREGISTER,SCAN]_HWIF ioctls as DANGEROUS
      and given the number of bugs we can assume that there are no real users:
      
      * DMA has no chance of working because DMA resources are released by
        ide_unregister() and they are never allocated again.
      
      * Since ide_init_hwif_ports() is used for ->io_ports[] setup the ioctls
        don't work for almost all hosts with "non-standard" (== non ISA-like)
        layout of IDE taskfile registers (there is a lot of such host drivers).
      
      * ide_port_init_devices() is not called when probing IDE devices so:
        - drive->autotune is never set and IDE host/devices are not programmed
          for the correct PIO/DMA transfer modes (=> possible data corruption)
        - host specific I/O 32-bit and IRQ unmasking settings are not applied
          (=> possible data corruption)
        - host specific ->port_init_devs method is not called (=> no luck with
          ht6560b, qd65xx and opti621 host drivers)
      
      * ->rw_disk method is not preserved (=> no HPT3xxN chipsets support).
      
      * ->serialized flag is not preserved (=> possible data corruption when
         using icside, aec62xx (ATP850UF chipset), cmd640, cs5530, hpt366
         (HPT3xxN chipsets), rz1000, sc1200, dtc2278 and ht6560b host drivers).
      
      * ->ack_intr method is not preserved (=> needed by ide-cris, buddha,
        gayle and macide host drivers).
      
      * ->sata_scr[] and sata_misc[] is cleared by ide_unregister() and it
        isn't initialized again (SiI3112 support needs them).
      
      * To issue an ioctl() there need to be at least one IDE device present
        in the system.
      
      * ->cable_detect method is not preserved + it is not called when probing
        IDE devices so cable detection is broken (however since DMA support is
        also broken it doesn't really matter ;-).
      
      * Some objects which may have already been freed in ide_unregister()
        are restored by ide_hwif_restore() (i.e. ->hwgroup).
      
      * ide_register_hw() may unregister unrelated IDE ports if free ide_hwifs[]
        slot cannot be found.
      
      * When IDE host drivers are modular unregistered port may be re-used by
        different host driver that owned it first causing subtle bugs.
      
      Since we now have a proper warm-plug support remove these ioctls,
      then remove no longer needed:
      - ide_register_hw() and ide_hwif_restore() functions
      - 'init_default' and 'restore' arguments of ide_unregister()
      - zeroeing of hwif->{dma,extra}_* fields in ide_unregister()
      
      As an added bonus IDE core code size shrinks by ~3kB (x86-32).
      
      v2:
      * fix ide_unregister() arguments in cleanup_module() (Andrew Morton).
      
      v3:
      * fix ide_unregister() arguments in palm_bk3710.c.
      Acked-by: default avatarSergei Shtylyov <sshtylyov@ru.mvista.com>
      Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      93de00fd
  12. 28 Jan, 2008 1 commit
  13. 29 Oct, 2007 1 commit
  14. 10 Oct, 2007 7 commits