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  1. 22 Dec, 2010 2 commits
  3. 20 Dec, 2010 2 commits
  5. 17 Dec, 2010 5 commits
  7. 16 Dec, 2010 12 commits
    • Jens Axboe's avatar
      Merge branch 'for-2.6.38/event-handling' into for-next · f3c1e66f
      Jens Axboe authored
      f3c1e66f
    • Jens Axboe's avatar
      cdrom: export cdrom_check_events() · 30a7caab
      Jens Axboe authored 
      It's used by sr, so we need to export it.
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      30a7caab
    • Jens Axboe's avatar
      Merge branch 'for-2.6.38/event-handling' into for-next · 8ae47c1e
      Jens Axboe authored
      8ae47c1e
    • Jens Axboe's avatar
      Merge branch 'for-2.6.38/core' into for-next · c4ffa146
      Jens Axboe authored
      c4ffa146
    • Tejun Heo's avatar
      sd: implement sd_check_events() · c8d2e937
      Tejun Heo authored 
      Replace sd_media_change() with sd_check_events().  sd used to set the
changed state whenever the device is not ready, which can cause event
loop while the device is not ready.  Media presence handling code is
changed such that the changed state is set iff the media presence
actually changes.  UA still always sets the changed state and
NOT_READY always (at least where it used to set ->changed) clears
media presence, so no event is lost.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      c8d2e937
    • Tejun Heo's avatar
      sr: implement sr_check_events() · 93aae17a
      Tejun Heo authored 
      Replace sr_media_change() with sr_check_events().  It normally only
uses GET_EVENT_STATUS_NOTIFICATION to check both media change and
eject request.  If @clearing includes DISK_EVENT_MEDIA_CHANGE, it
issues TUR and compares whether media presence has changed.  The SCSI
specific media change uevent is kept for compatibility.

sr_media_change() was doing both media change check and revalidation.
The revalidation part is split into sr_block_revalidate_disk().
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      93aae17a
    • Tejun Heo's avatar
      scsi: replace sr_test_unit_ready() with scsi_test_unit_ready() · 9f8a2c23
      Tejun Heo authored 
      The usage of TUR has been confusing involving several different
commits updating different parts over time.  Currently, the only
differences between scsi_test_unit_ready() and sr_test_unit_ready()
are,

* scsi_test_unit_ready() also sets sdev->changed on NOT_READY.

* scsi_test_unit_ready() returns 0 if TUR ended with UNIT_ATTENTION or
  NOT_READY.

Due to the above two differences, sr is using its own
sr_test_unit_ready(), but sd - the sole user of the above extra
handling - doesn't even need them.

Where scsi_test_unit_ready() is used in sd_media_changed(), the code
is looking for device ready w/ media present state which is true iff
TUR succeeds w/o sense data or UA, and when the device is not ready
for whatever reason sd_media_changed() explicitly marks media as
missing so there's no reason to set sdev->changed automatically from
scsi_test_unit_ready() on NOT_READY.

Drop both special handlings from scsi_test_unit_ready(), which makes
it equivalant to sr_test_unit_ready(), and replace
sr_test_unit_ready() with scsi_test_unit_ready().  Also, drop the
unnecessary explicit NOT_READY check from sd_media_changed().
Checking return value is enough for testing device readiness.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      9f8a2c23
    • Tejun Heo's avatar
      scsi: fix TUR error handling in sr_media_change() · 638428ec
      Tejun Heo authored 
      sr_test_unit_ready() returns 0 iff TUR succeeded - IOW, when media is
present and the device is actually ready, so the return value wouldn't
be zero when TUR ends with sense data. sr_media_change() incorrectly
tests (retval || (scsi_sense_valid(sshdr)...)) when it tries to test
whether TUR failed without sense data or with sense data indicating
media-not-present.

Fix the test using scsi_status_is_good() and update comments.

- Fixed a comment typo spotted by Eike.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      638428ec
    • Tejun Heo's avatar
      cdrom: add ->check_events() support · 2d921729
      Tejun Heo authored 
      In principle, cdrom just needs to pass through ->check_events() but
CDROM_MEDIA_CHANGED ioctl makes things a bit more complex.  Just as
with ->media_changed() support, cdrom code needs to buffer the events
and serve them to ioctl and vfs as requested.

As the code has to deal with both ->check_events() and
->media_changed(), and vfs and ioctl event buffering, this patch adds
check_events caching on top of the existing cdi->mc_flags buffering.

It may be a good idea to deprecate CDROM_MEDIA_CHANGED ioctl and
remove all this mess.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      2d921729
    • Tejun Heo's avatar
      implement in-kernel gendisk events handling · 77ea887e
      Tejun Heo authored 
      Currently, media presence polling for removeable block devices is done
from userland.  There are several issues with this.

* Polling is done by periodically opening the device.  For SCSI
  devices, the command sequence generated by such action involves a
  few different commands including TEST_UNIT_READY.  This behavior,
  while perfectly legal, is different from Windows which only issues
  single command, GET_EVENT_STATUS_NOTIFICATION.  Unfortunately, some
  ATAPI devices lock up after being periodically queried such command
  sequences.

* There is no reliable and unintrusive way for a userland program to
  tell whether the target device is safe for media presence polling.
  For example, polling for media presence during an on-going burning
  session can make it fail.  The polling program can avoid this by
  opening the device with O_EXCL but then it risks making a valid
  exclusive user of the device fail w/ -EBUSY.

* Userland polling is unnecessarily heavy and in-kernel implementation
  is lighter and better coordinated (workqueue, timer slack).

This patch implements framework for in-kernel disk event handling,
which includes media presence polling.

* bdops->check_events() is added, which supercedes ->media_changed().
  It should check whether there's any pending event and return if so.
  Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
  DISK_EVENT_EJECT_REQUEST.  ->check_events() is guaranteed not to be
  called parallelly.

* gendisk->events and ->async_events are added.  These should be
  initialized by block driver before passing the device to add_disk().
  The former contains the mask of all supported events and the latter
  the mask of all events which the device can report without polling.
  /sys/block/*/events[_async] export these to userland.

* Kernel parameter block.events_dfl_poll_msecs controls the system
  polling interval (default is 0 which means disable) and
  /sys/block/*/events_poll_msecs control polling intervals for
  individual devices (default is -1 meaning use system setting).  Note
  that if a device can report all supported events asynchronously and
  its polling interval isn't explicitly set, the device won't be
  polled regardless of the system polling interval.

* If a device is opened exclusively with write access, event checking
  is automatically disabled until all write exclusive accesses are
  released.

* There are event 'clearing' events.  For example, both of currently
  defined events are cleared after the device has been successfully
  opened.  This information is passed to ->check_events() callback
  using @clearing argument as a hint.

* Event checking is always performed from system_nrt_wq and timer
  slack is set to 25% for polling.

* Nothing changes for drivers which implement ->media_changed() but
  not ->check_events().  Going forward, all drivers will be converted
  to ->check_events() and ->media_change() will be dropped.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      77ea887e
    • Tejun Heo's avatar
      block: move register_disk() and del_gendisk() to block/genhd.c · d2bf1b67
      Tejun Heo authored 
      There's no reason for register_disk() and del_gendisk() to be in
fs/partitions/check.c.  Move both to genhd.c.  While at it, collapse
unlink_gendisk(), which was artificially in a separate function due to
genhd.c / check.c split, into del_gendisk().
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      d2bf1b67
    • Tejun Heo's avatar
      block: kill genhd_media_change_notify() · dddd9dc3
      Tejun Heo authored 
      There's no user of the facility.  Kill it.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      dddd9dc3
  9. 13 Dec, 2010 1 commit
  11. 30 Nov, 2010 2 commits
  13. 27 Nov, 2010 1 commit
  15. 16 Nov, 2010 4 commits
  17. 15 Nov, 2010 11 commits
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