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  1. 17 2月, 2010 5 次提交
    • T
      dm raid1: fix null pointer dereference in suspend · 558569aa
      由 Takahiro Yasui 提交于 
      When suspending a failed mirror, bios are completed by mirror_end_io() and
__rh_lookup() in dm_rh_dec() returns NULL where a non-NULL return value is
required by design.  Fix this by not changing the state of the recovery failed
region from DM_RH_RECOVERING to DM_RH_NOSYNC in dm_rh_recovery_end().

Issue

On 2.6.33-rc1 kernel, I hit the bug when I suspended the failed
mirror by dmsetup command.

BUG: unable to handle kernel NULL pointer dereference at 00000020
IP: [<f94f38e2>] dm_rh_dec+0x35/0xa1 [dm_region_hash]
...
EIP: 0060:[<f94f38e2>] EFLAGS: 00010046 CPU: 0
EIP is at dm_rh_dec+0x35/0xa1 [dm_region_hash]
EAX: 00000286 EBX: 00000000 ECX: 00000286 EDX: 00000000
ESI: eff79eac EDI: eff79e80 EBP: f6915cd4 ESP: f6915cc4
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process dmsetup (pid: 2849, ti=f6914000 task=eff03e80 task.ti=f6914000)
 ...
Call Trace:
 [<f9530af6>] ? mirror_end_io+0x53/0x1b1 [dm_mirror]
 [<f9413104>] ? clone_endio+0x4d/0xa2 [dm_mod]
 [<f9530aa3>] ? mirror_end_io+0x0/0x1b1 [dm_mirror]
 [<f94130b7>] ? clone_endio+0x0/0xa2 [dm_mod]
 [<c02d6bcb>] ? bio_endio+0x28/0x2b
 [<f952f303>] ? hold_bio+0x2d/0x62 [dm_mirror]
 [<f952f942>] ? mirror_presuspend+0xeb/0xf7 [dm_mirror]
 [<c02aa3e2>] ? vmap_page_range+0xb/0xd
 [<f9414c8d>] ? suspend_targets+0x2d/0x3b [dm_mod]
 [<f9414ca9>] ? dm_table_presuspend_targets+0xe/0x10 [dm_mod]
 [<f941456f>] ? dm_suspend+0x4d/0x150 [dm_mod]
 [<f941767d>] ? dev_suspend+0x55/0x18a [dm_mod]
 [<c0343762>] ? _copy_from_user+0x42/0x56
 [<f9417fb0>] ? dm_ctl_ioctl+0x22c/0x281 [dm_mod]
 [<f9417628>] ? dev_suspend+0x0/0x18a [dm_mod]
 [<f9417d84>] ? dm_ctl_ioctl+0x0/0x281 [dm_mod]
 [<c02c3c4b>] ? vfs_ioctl+0x22/0x85
 [<c02c422c>] ? do_vfs_ioctl+0x4cb/0x516
 [<c02c42b7>] ? sys_ioctl+0x40/0x5a
 [<c0202858>] ? sysenter_do_call+0x12/0x28

Analysis

When recovery process of a region failed, dm_rh_recovery_end() function
changes the state of the region from RM_RH_RECOVERING to DM_RH_NOSYNC.
When recovery_complete() is executed between dm_rh_update_states() and
dm_writes() in do_mirror(), bios are processed with the region state,
DM_RH_NOSYNC. However, the region data is freed without checking its
pending count when dm_rh_update_states() is called next time.

When bios are finished by mirror_end_io(), __rh_lookup() in dm_rh_dec()
returns NULL even though a valid return value are expected.

Solution

Remove the state change of the recovery failed region from DM_RH_RECOVERING
to DM_RH_NOSYNC in dm_rh_recovery_end(). We can remove the state change
because:

  - If the region data has been released by dm_rh_update_states(),
    a new region data is created with the state of DM_RH_NOSYNC, and
    bios are processed according to the DM_RH_NOSYNC state.

  - If the region data has not been released by dm_rh_update_states(),
    a state of the region is DM_RH_RECOVERING and bios are put in the
    delayed_bio list.

The flag change from DM_RH_RECOVERING to DM_RH_NOSYNC in dm_rh_recovery_end()
was added in the following commit:
  dm raid1: handle resync failures
  author  Jonathan Brassow <jbrassow@redhat.com>
    Thu, 12 Jul 2007 16:29:04 +0000 (17:29 +0100)
  http://git.kernel.org/linus/f44db678edcc6f4c2779ac43f63f0b9dfa28b724Signed-off-by: NTakahiro Yasui <tyasui@redhat.com>
Reviewed-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      558569aa
    • M
      dm raid1: fail writes if errors are not handled and log fails · 5528d17d
      由 Mikulas Patocka 提交于 
      If the mirror log fails when the handle_errors option was not selected
and there is no remaining valid mirror leg, writes return success even
though they weren't actually written to any device.  This patch
completes them with EIO instead.

This code path is taken:
do_writes:
	bio_list_merge(&ms->failures, &sync);
do_failures:
	if (!get_valid_mirror(ms)) (false)
	else if (errors_handled(ms)) (false)
	else bio_endio(bio, 0);

The logic in do_failures is based on presuming that the write was already
tried: if it succeeded at least on one leg (without handle_errors) it
is reported as success.

Reference: https://bugzilla.redhat.com/show_bug.cgi?id=555197Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      5528d17d
    • J
      dm log: userspace fix overhead_size calcuations · ebfd32bb
      由 Jonathan Brassow 提交于 
      This patch fixes two bugs that revolve around the miscalculation and
misuse of the variable 'overhead_size'.  'overhead_size' is the size of
the various header structures used during communication.

The first bug is the use of 'sizeof' with the pointer of a structure
instead of the structure itself - resulting in the wrong size being
computed.  This is then used in a check to see if the payload
(data_size) would be to large for the preallocated structure.  Since the
bug produces a smaller value for the overhead, it was possible for the
structure to be breached.  (Although the current users of the code do
not currently send enough data to trigger this bug.)

The second bug is that the 'overhead_size' value is used to compute how
much of the preallocated space should be cleared before populating it
with fresh data.  This should have simply been 'sizeof(struct cn_msg)'
not overhead_size.  The fact that 'overhead_size' was computed
incorrectly made this problem "less bad" - leaving only a pointer's
worth of space at the end uncleared.  Thus, this bug was never producing
a bad result, but still needs to be fixed - especially now that the
value is computed correctly.

Cc: stable@kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      ebfd32bb
    • M
      dm snapshot: persistent annotate work_queue as on stack · 55f67f2d
      由 Mike Snitzer 提交于 
      chunk_io() declares its 'struct mdata_req' on the stack and then
initializes its 'struct work_struct' member.  Annotate the
initialization of this workqueue with INIT_WORK_ON_STACK to suppress a
debugobjects warning seen when CONFIG_DEBUG_OBJECTS_WORK is enabled.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      55f67f2d
    • N
      dm stripe: avoid divide by zero with invalid stripe count · 781248c1
      由 Nikanth Karthikesan 提交于 
      If a table containing zero as stripe count is passed into stripe_ctr
the code attempts to divide by zero.

This patch changes DM_TABLE_LOAD to return -EINVAL if the stripe count
is zero.

We now get the following error messages:
  device-mapper: table: 253:0: striped: Invalid stripe count
  device-mapper: ioctl: error adding target to table
Signed-off-by: NNikanth Karthikesan <knikanth@suse.de>
Cc: stable@kernel.org
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      781248c1
  3. 16 2月, 2010 11 次提交
  5. 15 2月, 2010 6 次提交
  7. 14 2月, 2010 3 次提交
    • C
      firewire: ohci: retransmit isochronous transmit packets on cycle loss · 7f51a100
      由 Clemens Ladisch 提交于 
      In isochronous transmit DMA descriptors, link the skip address pointer
back to the descriptor itself.  When a cycle is lost, the controller
will send the packet in the next cycle, instead of terminating the
entire DMA program.

There are two reasons for this:

* This behaviour is compatible with the old IEEE1394 stack.  Old
  applications would not expect the DMA program to stop in this case.

* Since the OHCI driver does not report any uncompleted packets, the
  context would stop silently; clients would not have any chance to
  detect and handle this error without a watchdog timer.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>

Pieter Palmers notes:

"The reason I added this retry behavior to the old stack is because some
cards now and then fail to send a packet (e.g. the o2micro card in my
dell laptop).  I couldn't figure out why exactly this happens, my best
guess is that the card cannot fetch the payload data on time.  This
happens much more frequently when sending large packets, which leads me
to suspect that there are some contention issues with the DMA that fills
the transmit FIFO.

In the old stack it was a pretty critical issue as it resulted in a
freeze of the userspace application.

The omission of a packet doesn't necessarily have to be an issue.  E.g.
in IEC61883 streams the DBC field can be used to detect discontinuities
in the stream.  So as long as the other side doesn't bail when no
[packet] is present in a cycle, there is not really a problem.

I'm not convinced though that retrying is the proper solution, but it is
simple and effective for what it had to do.  And I think there are no
reasons not to do it this way.  Userspace can still detect this by
checking the cycle the descriptor was sent in."

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (changelog, comment)
      7f51a100
    • K
      perf top: Fix help text alignment · 1a72cfa6
      由 Kirill Smelkov 提交于 
      Print this:

Mapped keys:
        [d]     display refresh delay.                  (2)
        [e]     display entries (lines).                (46)
        [f]     profile display filter (count).         (5)
        [F]     annotate display filter (percent).      (5%)
        [s]     annotate symbol.                        (NULL)
        [S]     stop annotation.
        [K]     hide kernel_symbols symbols.            (no)
        [U]     hide user symbols.                      (no)
        [z]     toggle sample zeroing.                  (0)
        [qQ]    quit.

instead of:

Mapped keys:
        [d]     display refresh delay.                  (2)
        [e]     display entries (lines).                (46)
        [f]     profile display filter (count).         (5)
        [F]     annotate display filter (percent).      (5%)
        [s]     annotate symbol.                        (NULL)
        [S]     stop annotation.
        [K]     hide kernel_symbols symbols.                    (no)
        [U]     hide user symbols.                      (no)
        [z]     toggle sample zeroing.                  (0)
        [qQ]    quit.
Signed-off-by: NKirill Smelkov <kirr@landau.phys.spbu.ru>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100212162059.GA30041@landau.phys.spbu.ru>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1a72cfa6
    • H
      tracing/kprobes: Fix probe parsing · a9bb18f3
      由 Heiko Carstens 提交于 
      Trying to add a probe like:

  echo p:myprobe 0x10000 > /sys/kernel/debug/tracing/kprobe_events

will fail since the wrong pointer is passed to strict_strtoul
when trying to convert the address to an unsigned long.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100210162346.GA6933@osiris.boeblingen.de.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a9bb18f3
  9. 13 2月, 2010 9 次提交
  11. 12 2月, 2010 6 次提交