11 Dec, 2011

1 commit


22 Apr, 2011

1 commit

  • In-kernel disk event polling doesn't matter for legacy/fringe drivers
    and may lead to infinite event loop if ->check_events() implementation
    generates events on level condition instead of edge.

    Now that block layer supports suppressing exporting unlisted events,
    simply leaving disk->events cleared allows these drivers to keep the
    internal revalidation behavior intact while avoiding weird
    interactions with userland event handler.

    Signed-off-by: Tejun Heo
    Cc: Kay Sievers
    Signed-off-by: Jens Axboe

    Tejun Heo
     

10 Mar, 2011

1 commit

  • Convert from ->media_changed() to ->check_events().

    Both swim and swim3 buffer media changed state and clear it on
    revalidation. They will behave correctly with kernel event polling.

    Signed-off-by: Tejun Heo
    Cc: Jens Axboe
    Cc: Kay Sievers
    Cc: Laurent Vivier
    Cc: Benjamin Herrenschmidt

    Tejun Heo
     

05 Oct, 2010

1 commit

  • The block device drivers have all gained new lock_kernel
    calls from a recent pushdown, and some of the drivers
    were already using the BKL before.

    This turns the BKL into a set of per-driver mutexes.
    Still need to check whether this is safe to do.

    file=$1
    name=$2
    if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
    sed -i '/include.*/d' ${file}
    else
    sed -i 's/include.*.*$/include /g' ${file}
    fi
    sed -i ${file} \
    -e "/^#include.*linux.mutex.h/,$ {
    1,/^\(static\|int\|long\)/ {
    /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

    } }" \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[ ]*cycle_kernel_lock();/d'
    else
    sed -i -e '/include.*\/d' ${file} \
    -e '/cycle_kernel_lock()/d'
    fi

    Signed-off-by: Arnd Bergmann

    Arnd Bergmann
     

08 Aug, 2010

2 commits

  • The open and release block_device_operations are currently
    called with the BKL held. In order to change that, we must
    first make sure that all drivers that currently rely
    on this have no regressions.

    This blindly pushes the BKL into all .open and .release
    operations for all block drivers to prepare for the
    next step. The drivers can subsequently replace the BKL
    with their own locks or remove it completely when it can
    be shown that it is not needed.

    The functions blkdev_get and blkdev_put are the only
    remaining users of the big kernel lock in the block
    layer, besides a few uses in the ioctl code, none
    of which need to serialize with blkdev_{get,put}.

    Most of these two functions is also under the protection
    of bdev->bd_mutex, including the actual calls to
    ->open and ->release, and the common code does not
    access any global data structures that need the BKL.

    Signed-off-by: Arnd Bergmann
    Acked-by: Christoph Hellwig
    Signed-off-by: Jens Axboe

    Arnd Bergmann
     
  • As a preparation for the removal of the big kernel
    lock in the block layer, this removes the BKL
    from the common ioctl handling code, moving it
    into every single driver still using it.

    Signed-off-by: Arnd Bergmann
    Acked-by: Christoph Hellwig
    Signed-off-by: Jens Axboe

    Arnd Bergmann
     

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
     

28 Feb, 2010

1 commit

  • Adjust the platform device code to conform with the code style used in the
    rest of this patch series. No need to name resources nor to register
    devices which are not applicable.

    Signed-off-by: Finn Thain
    Signed-off-by: Geert Uytterhoeven

    Finn Thain
     

22 Sep, 2009

1 commit


11 May, 2009

3 commits

  • Till now block layer allowed two separate modes of request execution.
    A request is always acquired from the request queue via
    elv_next_request(). After that, drivers are free to either dequeue it
    or process it without dequeueing. Dequeue allows elv_next_request()
    to return the next request so that multiple requests can be in flight.

    Executing requests without dequeueing has its merits mostly in
    allowing drivers for simpler devices which can't do sg to deal with
    segments only without considering request boundary. However, the
    benefit this brings is dubious and declining while the cost of the API
    ambiguity is increasing. Segment based drivers are usually for very
    old or limited devices and as converting to dequeueing model isn't
    difficult, it doesn't justify the API overhead it puts on block layer
    and its more modern users.

    Previous patches converted all block low level drivers to dequeueing
    model. This patch completes the API transition by...

    * renaming elv_next_request() to blk_peek_request()

    * renaming blkdev_dequeue_request() to blk_start_request()

    * adding blk_fetch_request() which is combination of peek and start

    * disallowing completion of queued (not started) requests

    * applying new API to all LLDs

    Renamings are for consistency and to break out of tree code so that
    it's apparent that out of tree drivers need updating.

    [ Impact: block request issue API cleanup, no functional change ]

    Signed-off-by: Tejun Heo
    Cc: Rusty Russell
    Cc: James Bottomley
    Cc: Mike Miller
    Cc: unsik Kim
    Cc: Paul Clements
    Cc: Tim Waugh
    Cc: Geert Uytterhoeven
    Cc: David S. Miller
    Cc: Laurent Vivier
    Cc: Jeff Garzik
    Cc: Jeremy Fitzhardinge
    Cc: Grant Likely
    Cc: Adrian McMenamin
    Cc: Stephen Rothwell
    Cc: Bartlomiej Zolnierkiewicz
    Cc: Borislav Petkov
    Cc: Sergei Shtylyov
    Cc: Alex Dubov
    Cc: Pierre Ossman
    Cc: David Woodhouse
    Cc: Markus Lidel
    Cc: Stefan Weinhuber
    Cc: Martin Schwidefsky
    Cc: Pete Zaitcev
    Cc: FUJITA Tomonori
    Signed-off-by: Jens Axboe

    Tejun Heo
     
  • swim processes requests one-by-one synchronously and can easily be
    converted to dequeuing model. Convert it.

    [ Impact: dequeue in-flight request ]

    Signed-off-by: Tejun Heo
    Cc: Laurent Vivier
    Signed-off-by: Jens Axboe

    Tejun Heo
     
  • With recent cleanups, there is no place where low level driver
    directly manipulates request fields. This means that the 'hard'
    request fields always equal the !hard fields. Convert all
    rq->sectors, nr_sectors and current_nr_sectors references to
    accessors.

    While at it, drop superflous blk_rq_pos() < 0 test in swim.c.

    [ Impact: use pos and nr_sectors accessors ]

    Signed-off-by: Tejun Heo
    Acked-by: Geert Uytterhoeven
    Tested-by: Grant Likely
    Acked-by: Grant Likely
    Tested-by: Adrian McMenamin
    Acked-by: Adrian McMenamin
    Acked-by: Mike Miller
    Cc: James Bottomley
    Cc: Bartlomiej Zolnierkiewicz
    Cc: Borislav Petkov
    Cc: Sergei Shtylyov
    Cc: Eric Moore
    Cc: Alan Stern
    Cc: FUJITA Tomonori
    Cc: Pete Zaitcev
    Cc: Stephen Rothwell
    Cc: Paul Clements
    Cc: Tim Waugh
    Cc: Jeff Garzik
    Cc: Jeremy Fitzhardinge
    Cc: Alex Dubov
    Cc: David Woodhouse
    Cc: Martin Schwidefsky
    Cc: Dario Ballabio
    Cc: David S. Miller
    Cc: Rusty Russell
    Cc: unsik Kim
    Cc: Laurent Vivier
    Signed-off-by: Jens Axboe

    Tejun Heo
     

28 Apr, 2009

2 commits

  • swim curiously tries to update request parameters before calling
    __blk_end_request() when __blk_end_request() will do it anyway and
    unnecessarily checks whether current_nr_sectors is zero right after
    fetching.

    Drop unnecessary stuff and use standard block layer mechanisms.

    [ Impact: cleanup ]

    Signed-off-by: Tejun Heo
    Cc: Laurent Vivier
    Signed-off-by: Jens Axboe

    Tejun Heo
     
  • end_request() has been kept around for backward compatibility;
    however, it's about time for it to go away.

    * There aren't too many users left.

    * Its use of @updtodate is pretty confusing.

    * In some cases, newer code ends up using mixture of end_request() and
    [__]blk_end_request[_all](), which is way too confusing.

    So, add [__]blk_end_request_cur() and replace end_request() with it.
    Most conversions are straightforward. Noteworthy ones are...

    * paride/pcd: next_request() updated to take 0/-errno instead of 1/0.

    * paride/pf: pf_end_request() and next_request() updated to take
    0/-errno instead of 1/0.

    * xd: xd_readwrite() updated to return 0/-errno instead of 1/0.

    * mtd/mtd_blkdevs: blktrans_discard_request() updated to return
    0/-errno instead of 1/0. Unnecessary local variable res
    initialization removed from mtd_blktrans_thread().

    [ Impact: cleanup ]

    Signed-off-by: Tejun Heo
    Acked-by: Joerg Dorchain
    Acked-by: Geert Uytterhoeven
    Acked-by: Grant Likely
    Acked-by: Laurent Vivier
    Cc: Tim Waugh
    Cc: Stephen Rothwell
    Cc: Paul Mackerras
    Cc: Jeremy Fitzhardinge
    Cc: Markus Lidel
    Cc: David Woodhouse
    Cc: Pete Zaitcev
    Cc: unsik Kim

    Tejun Heo
     

27 Mar, 2009

1 commit