23 Feb, 2016

1 commit

  • The DM_TARGET_WILDCARD feature indicates that the "error" target may
    replace any target; even immutable targets. This feature will be useful
    to preserve the ability to replace the "multipath" target even once it
    is formally converted over to having the DM_TARGET_IMMUTABLE feature.

    Also, implicit in the DM_TARGET_WILDCARD feature flag being set is that
    .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined
    in the target_type.

    Signed-off-by: Mike Snitzer

    Mike Snitzer
     

10 Feb, 2015

1 commit

  • For blk-mq request-based DM the responsibility of allocating a cloned
    request is transfered from DM core to the target type. Doing so
    enables the cloned request to be allocated from the appropriate
    blk-mq request_queue's pool (only the DM target, e.g. multipath, can
    know which block device to send a given cloned request to).

    Care was taken to preserve compatibility with old-style block request
    completion that requires request-based DM _not_ acquire the clone
    request's queue lock in the completion path. As such, there are now 2
    different request-based DM target_type interfaces:
    1) the original .map_rq() interface will continue to be used for
    non-blk-mq devices -- the preallocated clone request is passed in
    from DM core.
    2) a new .clone_and_map_rq() and .release_clone_rq() will be used for
    blk-mq devices -- blk_get_request() and blk_put_request() are used
    respectively from these hooks.

    dm_table_set_type() was updated to detect if the request-based target is
    being stacked on blk-mq devices, if so DM_TYPE_MQ_REQUEST_BASED is set.
    DM core disallows switching the DM table's type after it is set. This
    means that there is no mixing of non-blk-mq and blk-mq devices within
    the same request-based DM table.

    [This patch was started by Keith and later heavily modified by Mike]

    Tested-by: Bart Van Assche
    Signed-off-by: Keith Busch
    Signed-off-by: Mike Snitzer

    Mike Snitzer
     

06 Sep, 2013

1 commit

  • It may be useful to switch a request-based table to the "error" target.
    Enhance the DM core to allow a hybrid target_type which is capable of
    handling either bios (via .map) or requests (via .map_rq).

    Add a request-based map function (.map_rq) to the "error" target_type;
    making it DM's first hybrid target. Train dm_table_set_type() to prefer
    the mapped device's established type (request-based or bio-based). If
    the mapped device doesn't have an established type default to making the
    table with the hybrid target(s) bio-based.

    Tested 'dmsetup wipe_table' to work on both bio-based and request-based
    devices.

    Signed-off-by: Mike Snitzer
    Signed-off-by: Joe Jin
    Signed-off-by: Jun'ichi Nomura
    Acked-by: Mikulas Patocka
    Signed-off-by: Alasdair G Kergon

    Mike Snitzer
     

02 Mar, 2013

1 commit


22 Dec, 2012

1 commit

  • This patch removes map_info from bio-based device mapper targets.
    map_info is still used for request-based targets.

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

    Mikulas Patocka
     

12 Aug, 2010

1 commit


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
     

03 Apr, 2009

2 commits

  • The tt_internal is really just a list_head to manage registered target_type
    in a double linked list,

    Here embed the list_head into target_type directly,
    1. to avoid kmalloc/kfree;
    2. then tt_internal is really unneeded;

    Cc: stable@kernel.org
    Signed-off-by: Cheng Renquan
    Signed-off-by: Alasdair G Kergon
    Reviewed-by: Alasdair G Kergon

    Cheng Renquan
     
  • The tt_internal's 'use' field is superfluous: the module's refcount can do
    the work properly. An acceptable side-effect is that this increases the
    reference counts reported by 'lsmod'.

    Remove the superfluous test when removing a target module.

    [Crash possible without this on SMP - agk]

    Cc: stable@kernel.org
    Signed-off-by: Cheng Renquan
    Signed-off-by: Alasdair G Kergon
    Reviewed-by: Alasdair G Kergon
    Reviewed-by: Jonathan Brassow

    Cheng Renquan
     

06 Jan, 2009

1 commit

  • Change dm_unregister_target to return void and use BUG() for error
    reporting.

    dm_unregister_target can only fail because of programming bug in the
    target driver. It can't fail because of user's behavior or disk errors.

    This patch changes unregister_target to return void and use BUG if
    someone tries to unregister non-registered target or unregister target
    that is in use.

    This patch removes code duplication (testing of error codes in all dm
    targets) and reports bugs in just one place, in dm_unregister_target. In
    some target drivers, these return codes were ignored, which could lead
    to a situation where bugs could be missed.

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

    Mikulas Patocka
     

20 Oct, 2007

1 commit


27 Jun, 2006

1 commit


01 Apr, 2006

1 commit


17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds