15 Dec, 2011

1 commit


07 Nov, 2011

1 commit

  • * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
    Revert "tracing: Include module.h in define_trace.h"
    irq: don't put module.h into irq.h for tracking irqgen modules.
    bluetooth: macroize two small inlines to avoid module.h
    ip_vs.h: fix implicit use of module_get/module_put from module.h
    nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
    include: replace linux/module.h with "struct module" wherever possible
    include: convert various register fcns to macros to avoid include chaining
    crypto.h: remove unused crypto_tfm_alg_modname() inline
    uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
    pm_runtime.h: explicitly requires notifier.h
    linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
    miscdevice.h: fix up implicit use of lists and types
    stop_machine.h: fix implicit use of smp.h for smp_processor_id
    of: fix implicit use of errno.h in include/linux/of.h
    of_platform.h: delete needless include
    acpi: remove module.h include from platform/aclinux.h
    miscdevice.h: delete unnecessary inclusion of module.h
    device_cgroup.h: delete needless include
    net: sch_generic remove redundant use of
    net: inet_timewait_sock doesnt need
    ...

    Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
    - drivers/media/dvb/frontends/dibx000_common.c
    - drivers/media/video/{mt9m111.c,ov6650.c}
    - drivers/mfd/ab3550-core.c
    - include/linux/dmaengine.h

    Linus Torvalds
     

01 Nov, 2011

1 commit


31 Oct, 2011

1 commit

  • This patch validates sdev pointer in scsi_dh_activate before proceeding further.

    Without this check we might see the panic as below. I have seen this
    panic multiple times..

    Call trace:

    #0 [ffff88007d647b50] machine_kexec at ffffffff81020902
    #1 [ffff88007d647ba0] crash_kexec at ffffffff810875b0
    #2 [ffff88007d647c70] oops_end at ffffffff8139c650
    #3 [ffff88007d647c90] __bad_area_nosemaphore at ffffffff8102dd15
    #4 [ffff88007d647d50] page_fault at ffffffff8139b8cf
    [exception RIP: scsi_dh_activate+0x82]
    RIP: ffffffffa0041922 RSP: ffff88007d647e00 RFLAGS: 00010046
    RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000000093c5
    RDX: 00000000000093c5 RSI: ffffffffa02e6640 RDI: ffff88007cc88988
    RBP: 000000000000000f R8: ffff88007d646000 R9: 0000000000000000
    R10: ffff880082293790 R11: 00000000ffffffff R12: ffff88007cc88988
    R13: 0000000000000000 R14: 0000000000000286 R15: ffff880037b845e0
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0000
    #5 [ffff88007d647e38] run_workqueue at ffffffff81060268
    #6 [ffff88007d647e78] worker_thread at ffffffff81060386
    #7 [ffff88007d647ee8] kthread at ffffffff81064436
    #8 [ffff88007d647f48] kernel_thread at ffffffff81003fba

    Signed-off-by: Babu Moger
    Cc: stable@kernel.org
    Signed-off-by: James Bottomley

    Moger, Babu
     

31 Aug, 2011

3 commits


25 Apr, 2011

1 commit


25 Jan, 2011

1 commit


22 Dec, 2010

1 commit

  • Currently, when scsi_dh_activate() returns with an error
    (e.g. SCSI_DH_NOSYS) the activate_complete callback is not called and
    the error is not propagated to DM mpath.

    When a SCSI device attached to a device handler is deleted, userland
    processes currently performing I/O on the device will have their I/O
    hang forever.

    - Set SCSI_DH_NOSYS error when the handler is in the process of being
    deleted (e.g. the SCSI device is in a SDEV_CANCEL or SDEV_DEL state).

    - Set SCSI_DH_DEV_OFFLINED error when device is in SDEV_OFFLINE state.

    - Call the activate_complete callback function directly from
    scsi_dh_activate if an error has been set (when either the scsi_dh
    internal data has already been deleted or is in the process of being
    deleted).

    The patch was tested in an iSCSI environment, RDAC H/W handler and
    multipath. In the following reproduction process, dd will I/O hang
    forever and the only way to release it will be to reboot the machine:
    1) Perform I/O on a multipath device:
    dd if=/dev/dm-0 of=/dev/zero bs=8k count=1000000 &
    2) Delete all slave SCSI devices contained in the mpath device:
    I) In an iSCSI environment, the easiest way to do this is by
    stopping iSCSI:
    /etc/init.d/iscsi stop
    II) Another way to delete the devices is by applying the following
    bash scriptlet:
    dm_devs=$(ls /sys/block/ | grep dm- | xargs)
    for dm_dev in $dm_devs; do
    devices=$(ls /sys/block/$dm_dev/slaves)
    for device in $devices; do
    echo 1 > /sys/block/$device/device/delete
    done
    done

    NOTE: when DM mpath's fail_path uses blk_abort_queue this scsi_dh change
    isn't strictly required. However, DM mpath's call to blk_abort_queue
    will soon be reverted because it has proven to be unsafe due to a race
    (between blk_abort_queue and scsi_request_fn) that can lead to list
    corruption. Therefore we cannot rely on blk_abort_queue via fail_path,
    but even if we could this scsi_dh change is still preferrable.

    Signed-off-by: Menny Hamburger
    Signed-off-by: Mike Snitzer
    Reviewed-by: Babu Moger
    Signed-off-by: James Bottomley

    Menny Hamburger
     

30 Mar, 2010

1 commit

  • …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
     

05 Dec, 2009

2 commits


23 Aug, 2009

2 commits

  • When we moved the device handler functionality from dm layer to SCSI layer
    we dropped the parameter functionality.

    This path adds an interface to scsi dh layer to set device handler
    parameters.

    Basically, multipath layer need to create a string with all the parameters
    and call scsi_dh_set_params() after it called scsi_dh_attach() on a
    device.

    If a device handler provides such an interface it will handle the parameters
    as it expects them.

    Reported-by: Eddie Williams
    Signed-off-by: Chandra Seetharaman
    Tested-by: Eddie Williams
    Signed-off-by: James Bottomley
    Signed-off-by: James Bottomley

    Chandra Seetharaman
     
  • Problem reported: http://marc.info/?l=dm-devel&m=124585978305866&w=2

    scsi_dh does not do a refernce count for attach/detach, and this affects
    the way it is supposed to work with multipath when a device is not
    in the dev_list of the hardware handler.

    This patch adds a reference count that counts each attach.

    Signed-off-by: Chandra Seetharaman
    Signed-off-by: James Bottomley
    Signed-off-by: James Bottomley

    Chandra Seetharaman
     

27 Jul, 2008

4 commits

  • Create a cache of devices that are seen in a system. This will avoid
    the unnecessary traversal of the device list in the scsi_dh when there
    are multiple luns of a same type.

    Signed-off-by: Chandra Seetharaman
    Signed-off-by: Hannes Reinecke
    Signed-off-by: James Bottomley

    Hannes Reinecke
     
  • multipath keeps a separate device table which may be
    more current than the built-in one.
    So we should make sure to always call ->attach whenever
    a multipath map with hardware handler is instantiated.
    And we should call ->detach on removal, too.

    [sekharan: update as per comments from agk]
    Signed-off-by: Hannes Reinecke
    Signed-off-by: Chandra Seetharaman
    Signed-off-by: James Bottomley

    Hannes Reinecke
     
  • Implement a 'dh_state' sdev attribute for dynamic device handler
    manipulation. A read on the attribute will return the name of
    the currently attached device handler or 'detached' if no handler
    is attached.
    The attribute allows the following strings to be written:
    - The name of the device handler to be attached if the state is
    'detached'.
    - 'activate' to trigger path activation if a device handler
    is attached.
    - 'detach' to detach the currently attached device handler.

    Signed-off-by: Hannes Reinecke
    Signed-off-by: Chandra Seetharaman
    Signed-off-by: James Bottomley

    Hannes Reinecke
     
  • Instead of having each and every driver implement its own
    device table scanning code we should rather implement a common
    routine and scan the device tables there.
    This allows us also to implement a general notifier chain
    callback for all device handler instead for one per handler.

    [sekharan: Fix rejections caused by conflicting bug fix]
    Signed-off-by: Hannes Reinecke
    Signed-off-by: Chandra Seetharaman
    Signed-off-by: James Bottomley

    Hannes Reinecke
     

05 Jun, 2008

1 commit

  • Some of the storage devices (that can be accessed through multiple paths),
    do need some special handling for
    1. Activating the passive path of the storage access.
    2. Decode and handle the special sense codes returned by the devices.
    3. Handle the I/Os being sent to the passive path, especially
    during the device probe time.
    when accessed through multiple paths.

    As of today this special device handling is done at the dm-multipath
    layer using dm-handlers. That works well for (1); for (2) to be handled
    at dm layer, scsi sense information need to be exported from SCSI to dm-layer,
    which is not very attractive; (3) cannot be done at all at the dm layer.

    Device handler has been moved to SCSI mainly to handle (2) and (3) properly.

    Signed-off-by: Chandra Seetharaman
    Signed-off-by: Mike Anderson
    Signed-off-by: Mike Christie
    Signed-off-by: James Bottomley

    Chandra Seetharaman