linux/block
Bartlomiej Zolnierkiewicz 93de00fd1c ide: remove broken/dangerous HDIO_[UNREGISTER,SCAN]_HWIF ioctls (take 3)
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: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-04-18 00:46:24 +02:00
..
as-iosched.c block: kill swap_io_context() 2008-02-01 11:34:49 +01:00
blk-barrier.c block: fix blkdev_issue_flush() not detecting and passing EOPNOTSUPP back 2008-03-04 11:47:46 +01:00
blk-core.c unexport blk_{get,put}_queue 2008-03-04 11:28:32 +01:00
blk-exec.c block: make core bits checkpatch compliant 2008-02-01 09:26:33 +01:00
blk-ioc.c cfq-iosched: add hlist for browsing parallel to the radix tree 2008-02-19 10:04:00 +01:00
blk-map.c block: fix shadowed variable warning in blk-map.c 2008-03-04 11:31:22 +01:00
blk-merge.c block: restore the meaning of rq->data_len to the true data length 2008-03-04 11:17:11 +01:00
blk-settings.c Fix bounce setting for 64-bit 2008-04-02 09:06:44 +02:00
blk-sysfs.c block: make core bits checkpatch compliant 2008-02-01 09:26:33 +01:00
blk-tag.c block/blk-tag.c should #include "blk.h" 2008-03-04 11:28:24 +01:00
blk.h proper prototype for blk_dev_init() 2008-03-04 11:28:29 +01:00
blktrace.c blktrace: Add blktrace ioctls to SCSI generic devices 2008-01-28 10:04:46 +01:00
bsg.c block: restore the meaning of rq->data_len to the true data length 2008-03-04 11:17:11 +01:00
cfq-iosched.c cfq-iosched: do not leak ioc_data across iosched switches 2008-04-10 08:28:01 +02:00
compat_ioctl.c ide: remove broken/dangerous HDIO_[UNREGISTER,SCAN]_HWIF ioctls (take 3) 2008-04-18 00:46:24 +02:00
deadline-iosched.c block: let elv_register() return void 2007-12-18 08:29:28 +01:00
elevator.c elevator: make elevator_get() attempt to load the appropriate module 2008-02-19 10:20:37 +01:00
genhd.c genhd must_check warning fix 2008-03-12 12:34:37 -07:00
ioctl.c compat_ioctl: move common block ioctls to compat_blkdev_ioctl 2007-10-10 09:26:00 +02:00
Kconfig block: update git url for blktrace 2008-04-15 10:23:35 +02:00
Kconfig.iosched update I/O sched Kconfig help texts - CFQ is now default, not AS. 2007-02-17 20:08:22 +01:00
Makefile block: ll_rw_blk.c split, add blk-merge.c 2008-01-29 21:55:12 +01:00
noop-iosched.c block: let elv_register() return void 2007-12-18 08:29:28 +01:00
scsi_ioctl.c block: restore the meaning of rq->data_len to the true data length 2008-03-04 11:17:11 +01:00