Eric Lee / smarc-fsl-linux-kernel

31 Mar, 2011

1 commit

10 Sep, 2010

1 commit

  • d87f4c14f   dm: implement REQ_FLUSH/FUA support for bio-based dm ... Browse Code »

    This patch converts bio-based dm to support REQ_FLUSH/FUA instead of
    now deprecated REQ_HARDBARRIER.

    * -EOPNOTSUPP handling logic dropped.

    * Preflush is handled as before but postflush is dropped and replaced
    with passing down REQ_FUA to member request_queues. This replaces
    one array wide cache flush w/ member specific FUA writes.

    * __split_and_process_bio() now calls __clone_and_map_flush() directly
    for flushes and guarantees all FLUSH bio's going to targets are zero
    ` length.

    * It's now guaranteed that all FLUSH bio's which are passed onto dm
    targets are zero length. bio_empty_barrier() tests are replaced
    with REQ_FLUSH tests.

    * Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes.

    * Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely
    enough to be marked with unlikely().

    * Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue
    doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA
    capability.

    * Request based dm isn't converted yet. dm_init_request_based_queue()
    resets flush support to 0 for now. To avoid disturbing request
    based dm code, dm->flush_error is added for bio based dm while
    requested based dm continues to use dm->barrier_error.

    Lightly tested linear, stripe, raid1, snap and crypt targets. Please
    proceed with caution as I'm not familiar with the code base.

    Signed-off-by: Tejun Heo
    Cc: dm-devel@redhat.com
    Cc: Christoph Hellwig
    Signed-off-by: Jens Axboe

    Tejun Heo
     

30 Mar, 2010

1 commit

  • 5a0e3ad6a   include cleanup: Update gfp.h and slab.h includes to prepare for breaking implic… ... Browse Code »

    …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

17 Feb, 2010

1 commit

  • 558569aa9   dm raid1: fix null pointer dereference in suspend ... Browse Code »

    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: [] dm_rh_dec+0x35/0xa1 [dm_region_hash]
    ...
    EIP: 0060:[] 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:
    [] ? mirror_end_io+0x53/0x1b1 [dm_mirror]
    [] ? clone_endio+0x4d/0xa2 [dm_mod]
    [] ? mirror_end_io+0x0/0x1b1 [dm_mirror]
    [] ? clone_endio+0x0/0xa2 [dm_mod]
    [] ? bio_endio+0x28/0x2b
    [] ? hold_bio+0x2d/0x62 [dm_mirror]
    [] ? mirror_presuspend+0xeb/0xf7 [dm_mirror]
    [] ? vmap_page_range+0xb/0xd
    [] ? suspend_targets+0x2d/0x3b [dm_mod]
    [] ? dm_table_presuspend_targets+0xe/0x10 [dm_mod]
    [] ? dm_suspend+0x4d/0x150 [dm_mod]
    [] ? dev_suspend+0x55/0x18a [dm_mod]
    [] ? _copy_from_user+0x42/0x56
    [] ? dm_ctl_ioctl+0x22c/0x281 [dm_mod]
    [] ? dev_suspend+0x0/0x18a [dm_mod]
    [] ? dm_ctl_ioctl+0x0/0x281 [dm_mod]
    [] ? vfs_ioctl+0x22/0x85
    [] ? do_vfs_ioctl+0x4cb/0x516
    [] ? sys_ioctl+0x40/0x5a
    [] ? 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
    Thu, 12 Jul 2007 16:29:04 +0000 (17:29 +0100)
    http://git.kernel.org/linus/f44db678edcc6f4c2779ac43f63f0b9dfa28b724

    Signed-off-by: Takahiro Yasui
    Reviewed-by: Mikulas Patocka
    Signed-off-by: Alasdair G Kergon

    Takahiro Yasui
     

11 Dec, 2009

2 commits

22 Jun, 2009

1 commit

  • a72986c56   dm raid1: keep retrying alloc if mempool_alloc failed ... Browse Code »

    If the code can't handle allocation failures, use __GFP_NOFAIL so that
    in case of memory pressure the allocator will retry indefinitely and
    won't return NULL which would cause a crash in the function.

    This is still not a correct fix, it may cause a classic deadlock when
    memory manager waits for I/O being done and I/O waits for some free memory.
    I/O code shouldn't allocate any memory. But in this case it probably
    doesn't matter much in practice, people usually do not swap on RAID.

    Signed-off-by: Mikulas Patocka
    Signed-off-by: Alasdair G Kergon

    Mikulas Patocka
     

15 Apr, 2009

1 commit

22 Oct, 2008

1 commit