This is base kernel patch for ptrace RSE bug. It's basically a backport
from the utrace RSE patch I sent out several weeks ago. please review.

when a thread is stopped (ptraced), debugger might change thread's user
stack (change memory directly), and we must avoid the RSE stored in
kernel to override user stack (user space's RSE is newer than kernel's
in the case). To workaround the issue, we copy kernel RSE to user RSE
before the task is stopped, so user RSE has updated data.  we then copy
user RSE to kernel after the task is resummed from traced stop and
kernel will use the newer RSE to return to user.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
CC: Roland McGrath <roland@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Since the RSE synchronization will need a TIF_ flag, but all

work-to-be-done bits are already used, so we have to multiplex
TIF_NOTIFY_RESUME again.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Add ia64 hooks for the new syscalls that were added in
commit 4d672e7aSigned-off-by: Tony Luck <tony.luck@intel.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (44 commits)
  dm raid1: report fault status
  dm raid1: handle read failures
  dm raid1: fix EIO after log failure
  dm raid1: handle recovery failures
  dm raid1: handle write failures
  dm snapshot: combine consecutive exceptions in memory
  dm: stripe enhanced status return
  dm: stripe trigger event on failure
  dm log: auto load modules
  dm: move deferred bio flushing to workqueue
  dm crypt: use async crypto
  dm crypt: prepare async callback fn
  dm crypt: add completion for async
  dm crypt: add async request mempool
  dm crypt: extract scatterlist processing
  dm crypt: tidy io ref counting
  dm crypt: introduce crypt_write_io_loop
  dm crypt: abstract crypt_write_done
  dm crypt: store sector mapping in dm_crypt_io
  dm crypt: move queue functions
  ...

* 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6: (59 commits)
  hwmon: (lm80) Add individual alarm files
  hwmon: (lm80) De-macro the sysfs callbacks
  hwmon: (lm80) Various cleanups
  hwmon: (w83627hf) Refactor beep enable handling
  hwmon: (w83627hf) Add individual alarm and beep files
  hwmon: (w83627hf) Enable VBAT monitoring
  hwmon: (w83627ehf) The W83627DHG has 8 VID pins
  hwmon: (asb100) Add individual alarm files
  hwmon: (asb100) De-macro the sysfs callbacks
  hwmon: (asb100) Various cleanups
  hwmon: VRM is not written to registers
  hwmon: (dme1737) fix Super-IO device ID override
  hwmon: (dme1737) fix divide-by-0
  hwmon: (abituguru3) Add AUX4 fan input for Abit IP35 Pro
  hwmon: Add support for Texas Instruments/Burr-Brown ADS7828
  hwmon: (adm9240) Add individual alarm files
  hwmon: (lm77) Add individual alarm files
  hwmon: Discard useless I2C driver IDs
  hwmon: (lm85) Make the pwmN_enable files writable
  hwmon: (lm85) Return standard values in pwmN_enable
  ...

* 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6: (62 commits)
  [XFS] add __init/__exit mark to specific init/cleanup functions
  [XFS] Fix oops in xfs_file_readdir()
  [XFS] kill xfs_root
  [XFS] keep i_nlink updated and use proper accessors
  [XFS] stop updating inode->i_blocks
  [XFS] Make xfs_ail_check check less by default
  [XFS] Move AIL pushing into it's own thread
  [XFS] use generic_permission
  [XFS] stop re-checking permissions in xfs_swapext
  [XFS] clean up xfs_swapext
  [XFS] remove permission check from xfs_change_file_space
  [XFS] prevent panic during log recovery due to bogus op_hdr length
  [XFS] Cleanup various fid related bits:
  [XFS] Fix xfs_lowbit64
  [XFS] Remove CFORK macros and use code directly in IFORK and DFORK macros.
  [XFS] kill superflous buffer locking (2nd attempt)
  [XFS] Use kernel-supplied "roundup_pow_of_two" for simplicity
  [XFS] Remove the BPCSHIFT and NB* based macros from XFS.
  [XFS] Remove bogus assert
  [XFS] optimize XFS_IS_REALTIME_INODE w/o realtime config
  ...

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Douglas Gilbert <dougg@torque.net>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'slub-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm:
  SLUB: fix checkpatch warnings
  Use non atomic unlock
  SLUB: Support for performance statistics
  SLUB: Alternate fast paths using cmpxchg_local
  SLUB: Use unique end pointer for each slab page.
  SLUB: Deal with annoying gcc warning on kfree()

This patch adds extra information to the mirror status output, so that
it can be determined which device(s) have failed.  For each mirror device,
a character is printed indicating the most severe error encountered.  The
characters are:
 *    A => Alive - No failures
 *    D => Dead - A write failure occurred leaving mirror out-of-sync
 *    S => Sync - A sychronization failure occurred, mirror out-of-sync
 *    R => Read - A read failure occurred, mirror data unaffected
This allows userspace to properly reconfigure the mirror set.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

This patch gives the ability to respond-to/record device failures
that happen during read operations.  It also adds the ability to
read from mirror devices that are not the primary if they are
in-sync.

There are essentially two read paths in mirroring; the direct path
and the queued path.  When a read request is mapped, if the region
is 'in-sync' the direct path is taken; otherwise the queued path
is taken.

If the direct path is taken, we must record bio information so that
if the read fails we can retry it.  We then discover the status of
a direct read through mirror_end_io.  If the read has failed, we will
mark the device from which the read was attempted as failed (so we
don't try to read from it again), restore the bio and try again.

If the queued path is taken, we discover the results of the read
from 'read_callback'.  If the device failed, we will mark the device
as failed and attempt the read again if there is another device
where this region is known to be 'in-sync'.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

This patch adds the ability to requeue write I/O to
core device-mapper when there is a log device failure.

If a write to the log produces and error, the pending writes are
put on the "failures" list.  Since the log is marked as failed,
they will stay on the failures list until a suspend happens.

Suspends come in two phases, presuspend and postsuspend.  We must
make sure that all the writes on the failures list are requeued
in the presuspend phase (a requirement of dm core).  This means
that recovery must be complete (because writes may be delayed
behind it) and the failures list must be requeued before we
return from presuspend.

The mechanisms to ensure recovery is complete (or stopped) was
already in place, but needed to be moved from postsuspend to
presuspend.  We rely on 'flush_workqueue' to ensure that the
mirror thread is complete and therefore, has requeued all writes
in the failures list.

Because we are using flush_workqueue, we must ensure that no
additional 'queue_work' calls will produce additional I/O
that we need to requeue (because once we return from
presuspend, we are unable to do anything about it).  'queue_work'
is called in response to the following functions:
- complete_resync_work = NA, recovery is stopped
- rh_dec (mirror_end_io) = NA, only calls 'queue_work' if it
                           is ready to recover the region
                           (recovery is stopped) or it needs
                           to clear the region in the log*
                           **this doesn't get called while
                           suspending**
- rh_recovery_end = NA, recovery is stopped
- rh_recovery_start = NA, recovery is stopped
- write_callback = 1) Writes w/o failures simply call
                   bio_endio -> mirror_end_io -> rh_dec
                   (see rh_dec above)
                   2) Writes with failures are put on
                   the failures list and queue_work is
                   called**
                   ** write_callbacks don't happen
                   during suspend **
- do_failures = NA, 'queue_work' not called if suspending
- add_mirror (initialization) = NA, only done on mirror creation
- queue_bio = NA, 1) delayed I/O scheduled before flush_workqueue
              is called.  2) No more I/Os are being issued.
              3) Re-attempted READs can still be handled.
              (Write completions are handled through rh_dec/
              write_callback - mention above - and do not
              use queue_bio.)
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

This patch adds the calls to 'fail_mirror' if an error occurs during
mirror recovery (aka resynchronization).  'fail_mirror' is responsible
for recording the type of error by mirror device and ensuring an event
gets raised for the purpose of notifying userspace.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

This patch gives mirror the ability to handle device failures
during normal write operations.

The 'write_callback' function is called when a write completes.
If all the writes failed or succeeded, we report failure or
success respectively.  If some of the writes failed, we call
fail_mirror; which increments the error count for the device, notes
the type of error encountered (DM_RAID1_WRITE_ERROR),  and
selects a new primary (if necessary).  Note that the primary
device can never change while the mirror is not in-sync (IOW,
while recovery is happening.)  This means that the scenario
where a failed write changes the primary and gives
recovery_complete a chance to misread the primary never happens.
The fact that the primary can change has necessitated the change
to the default_mirror field.  We need to protect against reading
garbage while the primary changes.  We then add the bio to a new
list in the mirror set, 'failures'.  For every bio in the 'failures'
list, we call a new function, '__bio_mark_nosync', where we mark
the region 'not-in-sync' in the log and properly set the region
state as, RH_NOSYNC.  Userspace must also be notified of the
failure.  This is done by 'raising an event' (dm_table_event()).
If fail_mirror is called in process context the event can be raised
right away.  If in interrupt context, the event is deferred to the
kmirrord thread - which raises the event if 'event_waiting' is set.

Backwards compatibility is maintained by ignoring errors if
the DM_FEATURES_HANDLE_ERRORS flag is not present.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Provided sector_t is 64 bits, reduce the in-memory footprint of the
snapshot exception table by the simple method of using unused bits of
the chunk number to combine consecutive entries.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

This patch adds additional information to the status line. It is added at the
end of the returned text so it will not interfere with existing
implementations using this data. The addition of this information will allow
for a common return interface to match that returned with the dm-raid1.c
status line (with Jonathan Brassow's patches).

Here is a sample of what is returned with a mirror "status" call:
isw_eeaaabgfg_mirror: 0 488390920 mirror 2 8:16 8:32 3727/3727 1 AA 1 core

Here's what's returned with this patch for a stripe "status" call:
isw_dheeijjdej_stripe: 0 976783872 striped 2 8:16 8:32 1 AA
Signed-off-by: Brian Wood <brian.j.wood@intel.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

This patch adds the stripe_end_io function to process errors that might
occur after an IO operation. As part of this there are a number of
enhancements made to record and trigger events:

- New atomic variable in struct stripe to record the number of
errors each stripe volume device has experienced (could be used
later with uevents to report back directly to userspace)

- New workqueue/work struct setup to process the trigger_event function

- New end_io function. It is here that testing for BIO error conditions
take place. It determines the exact stripe that cause the error,
records this in the new atomic variable, and calls the queue_work() function

- New trigger_event function to process failure events. This
calls dm_table_event()
Signed-off-by: Brian Wood <brian.j.wood@intel.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

If the log type is not recognised, attempt to load the module
'dm-log-<type>.ko'.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Add a single-thread workqueue for each mapped device
and move flushing of the lists of pushback and deferred bios
to this new workqueue.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm-crypt: Use crypto ablkcipher interface

Move encrypt/decrypt core to async crypto call.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm-crypt: Use crypto ablkcipher interface

Prepare callback function for async crypto operation.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm-crypt: Use crypto ablkcipher interface
Prepare completion for async crypto request.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm-crypt: Use crypto ablkcipher interface

Introduce mempool for async crypto requests.

cc->req is used mainly during synchronous operations
(to prevent allocation and deallocation of the same object).
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm-crypt: Use crypto ablkcipher interface

Move scatterlists to separate dm_crypt_struct and
pick out block processing from crypt_convert.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Make io reference counting more obvious.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Introduce crypt_write_io_loop().
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Process write request in separate function and queue
final bio through io workqueue.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Add sector into dm_crypt_io instead of using local variable.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Reorder kcryptd functions for clarity.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Rename functions to follow calling convention.
Prepare write io error processing function skeleton.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Simplify crypt_endio function.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Move error code setting outside of crypt_dec_pending function.
Use -EIO if crypt_convert_scatterlist() fails.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Remove write attribute from convert_context and use bio flag instead.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Move convert_context inside dm_crypt_io.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

A static declaration missing.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Drop the EXPERIMENTAL tag from well-established device-mapper targets, so
the newer ones stand out better.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Move completion wait to separate function
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Change io_locking to allow processing flush in separate thread.

Because we have DMF_BLOCK_IO already set, any possible
new ios are queued in dm_requests now.

In the case of interrupting previous wait there can be more
ios queued (we unlocked io_lock for a while) but this is safe.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Tidy dm_suspend function

 - change return value logic in dm_suspend
 - use atomic_read only once.
 - move DMF_BLOCK_IO clearing into one place
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Refactor deferred bio_list processing.

 - use separate _merge_pushback_list function
 - move deferred bio list pick up to flush function
 - use bio_list_pop instead of bio_list_get
 - simplify noflush flag use

No real functional change in this patch.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Tidy labels in alloc_dev to make later patches more clear.

No functional change in this patch.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>