1. 17 Jul, 2015 1 commit
    • Jens Axboe's avatar
      block: make /sys/block/<dev>/queue/discard_max_bytes writeable · 0034af03
      Jens Axboe authored
      Lots of devices support huge discard sizes these days. Depending
      on how the device handles them internally, huge discards can
      introduce massive latencies (hundreds of msec) on the device side.
      We have a sysfs file, discard_max_bytes, that advertises the max
      hardware supported discard size. Make this writeable, and split
      the settings into a soft and hard limit. This can be set from
      'discard_granularity' and up to the hardware limit.
      Add a new sysfs file, 'discard_max_hw_bytes', that shows the hw
      set limit.
      Reviewed-by: default avatarJeff Moyer <jmoyer@redhat.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
  2. 31 Mar, 2015 1 commit
    • Mike Snitzer's avatar
      block: fix blk_stack_limits() regression due to lcm() change · e9637415
      Mike Snitzer authored
      Linux 3.19 commit 69c953c8 ("lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n")
      caused blk_stack_limits() to not properly stack queue_limits for stacked
      devices (e.g. DM).
      Fix this regression by establishing lcm_not_zero() and switching
      blk_stack_limits() over to using it.
      DM uses blk_set_stacking_limits() to establish the initial top-level
      queue_limits that are then built up based on underlying devices' limits
      using blk_stack_limits().  In the case of optimal_io_size (io_opt)
      blk_set_stacking_limits() establishes a default value of 0.  With commit
      69c953c8, lcm(0, n) is no longer n, which compromises proper stacking of
      the underlying devices' io_opt.
      $ modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536
      $ cat /sys/block/sde/queue/optimal_io_size
      $ dmsetup create node --table "0 100 linear /dev/sde 0"
      Before this fix:
      $ cat /sys/block/dm-5/queue/optimal_io_size
      After this fix:
      $ cat /sys/block/dm-5/queue/optimal_io_size
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Cc: stable@vger.kernel.org # 3.19+
      Acked-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
  3. 21 Oct, 2014 1 commit
    • Christoph Hellwig's avatar
      block: remove artifical max_hw_sectors cap · 34b48db6
      Christoph Hellwig authored
      Set max_sectors to the value the drivers provides as hardware limit by
      default.  Linux had proper I/O throttling for a long time and doesn't
      rely on a artifically small maximum I/O size anymore.  By not limiting
      the I/O size by default we remove an annoying tuning step required for
      most Linux installation.
      Note that both the user, and if absolutely required the driver can still
      impose a limit for FS requests below max_hw_sectors_kb.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
  4. 09 Oct, 2014 1 commit
  5. 10 Jun, 2014 1 commit
  6. 05 Jun, 2014 1 commit
    • Jens Axboe's avatar
      block: add notion of a chunk size for request merging · 762380ad
      Jens Axboe authored
      Some drivers have different limits on what size a request should
      optimally be, depending on the offset of the request. Similar to
      dividing a device into chunks. Add a setting that allows the driver
      to inform the block layer of such a chunk size. The block layer will
      then prevent merging across the chunks.
      This is needed to optimally support NVMe with a non-zero stripe size.
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
  7. 08 Jan, 2014 1 commit
    • Kent Overstreet's avatar
      bcache/md: Use raid stripe size · c78afc62
      Kent Overstreet authored
      Now that we've got code for raid5/6 stripe awareness, bcache just needs
      to know about the stripes and when writing partial stripes is expensive
      - we probably don't want to enable this optimization for raid1 or 10,
      even though they have stripes. So add a flag to queue_limits.
      Signed-off-by: default avatarKent Overstreet <kmo@daterainc.com>
  8. 08 Nov, 2013 1 commit
  9. 31 Oct, 2013 1 commit
  10. 14 Dec, 2012 1 commit
  11. 20 Sep, 2012 1 commit
    • Martin K. Petersen's avatar
      block: Implement support for WRITE SAME · 4363ac7c
      Martin K. Petersen authored
      The WRITE SAME command supported on some SCSI devices allows the same
      block to be efficiently replicated throughout a block range. Only a
      single logical block is transferred from the host and the storage device
      writes the same data to all blocks described by the I/O.
      This patch implements support for WRITE SAME in the block layer. The
      blkdev_issue_write_same() function can be used by filesystems and block
      drivers to replicate a buffer across a block range. This can be used to
      efficiently initialize software RAID devices, etc.
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Acked-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
  12. 01 Aug, 2012 1 commit
  13. 11 Jan, 2012 1 commit
    • Martin K. Petersen's avatar
      block: Introduce blk_set_stacking_limits function · b1bd055d
      Martin K. Petersen authored
      Stacking driver queue limits are typically bounded exclusively by the
      capabilities of the low level devices, not by the stacking driver
      This patch introduces blk_set_stacking_limits() which has more liberal
      metrics than the default queue limits function. This allows us to
      inherit topology parameters from bottom devices without manually
      tweaking the default limits in each driver prior to calling the stacking
      Since there is now a clear distinction between stacking and low-level
      devices, blk_set_default_limits() has been modified to carry the more
      conservative values that we used to manually set in
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Acked-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
  14. 18 May, 2011 1 commit
  15. 06 May, 2011 1 commit
  16. 18 Apr, 2011 1 commit
  17. 12 Apr, 2011 1 commit
  18. 10 Mar, 2011 1 commit
  19. 03 Mar, 2011 1 commit
    • Vivek Goyal's avatar
      block: Initialize ->queue_lock to internal lock at queue allocation time · c94a96ac
      Vivek Goyal authored
      There does not seem to be a clear convention whether q->queue_lock is
      initialized or not when blk_cleanup_queue() is called. In the past it
      was not necessary but now blk_throtl_exit() takes up queue lock by
      default and needs queue lock to be available.
      In fact elevator_exit() code also has similar requirement just that it
      is less stringent in the sense that elevator_exit() is called only if
      elevator is initialized.
      Two problems have been noticed because of ambiguity about spin lock
            - If a driver calls blk_alloc_queue() and then soon calls
              blk_cleanup_queue() almost immediately, (because some other
      	driver structure allocation failed or some other error happened)
      	then blk_throtl_exit() will run into issues as queue lock is not
      	initialized. Loop driver ran into this issue recently and I
      	noticed error paths in md driver too. Similar error paths should
      	exist in other drivers too.
            - If some driver provided external spin lock and zapped the lock
              before blk_cleanup_queue(), then it can lead to issues.
      So this patch initializes the default queue lock at queue allocation time.
      block throttling code is one of the users of queue lock and it is
      initialized at the queue allocation time, so it makes sense to
      initialize ->queue_lock also to internal lock. A driver can overide that
      lock later. This will take care of the issue where a driver does not have
      to worry about initializing the queue lock to default before calling
      Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
  20. 17 Dec, 2010 2 commits
    • Mike Snitzer's avatar
      block: max hardware sectors limit wrapper · 72d4cd9f
      Mike Snitzer authored
      Implement blk_limits_max_hw_sectors() and make
      blk_queue_max_hw_sectors() a wrapper around it.
      DM needs this to avoid setting queue_limits' max_hw_sectors and
      max_sectors directly.  dm_set_device_limits() now leverages
      blk_limits_max_hw_sectors() logic to establish the appropriate
      max_hw_sectors minimum (PAGE_SIZE).  Fixes issue where DM was
      incorrectly setting max_sectors rather than max_hw_sectors (which
      caused dm_merge_bvec()'s max_hw_sectors check to be ineffective).
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Cc: stable@kernel.org
      Acked-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
    • Martin K. Petersen's avatar
      block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead · e692cb66
      Martin K. Petersen authored
      When stacking devices, a request_queue is not always available. This
      forced us to have a no_cluster flag in the queue_limits that could be
      used as a carrier until the request_queue had been set up for a
      There were several problems with that approach. First of all it was up
      to the stacking device to remember to set queue flag after stacking had
      completed. Also, the queue flag and the queue limits had to be kept in
      sync at all times. We got that wrong, which could lead to us issuing
      commands that went beyond the max scatterlist limit set by the driver.
      The proper fix is to avoid having two flags for tracking the same thing.
      We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the
      block layer merging functions. The queue_limit 'no_cluster' is turned
      into 'cluster' to avoid double negatives and to ease stacking.
      Clustering defaults to being enabled as before. The queue flag logic is
      removed from the stacking function, and explicitly setting the cluster
      flag is no longer necessary in DM and MD.
      Reported-by: default avatarEd Lin <ed.lin@promise.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Acked-by: default avatarMike Snitzer <snitzer@redhat.com>
      Cc: stable@kernel.org
      Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
  21. 13 Oct, 2010 1 commit
  22. 01 Oct, 2010 2 commits
  23. 24 Sep, 2010 1 commit
  24. 10 Sep, 2010 3 commits
    • Martin K. Petersen's avatar
      block/scsi: Provide a limit on the number of integrity segments · 13f05c8d
      Martin K. Petersen authored
      Some controllers have a hardware limit on the number of protection
      information scatter-gather list segments they can handle.
      Introduce a max_integrity_segments limit in the block layer and provide
      a new scsi_host_template setting that allows HBA drivers to provide a
      value suitable for the hardware.
      Add support for honoring the integrity segment limit when merging both
      bios and requests.
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarJens Axboe <axboe@carl.home.kernel.dk>
    • Martin K. Petersen's avatar
      Consolidate min_not_zero · c8bf1336
      Martin K. Petersen authored
      We have several users of min_not_zero, each of them using their own
      definition.  Move the define to kernel.h.
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarJens Axboe <axboe@carl.home.kernel.dk>
    • Tejun Heo's avatar
      block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush() · 4913efe4
      Tejun Heo authored
      Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
      requests.  Deprecate barrier.  All REQ_HARDBARRIERs are failed with
      -EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
      blk_queue_flush() takes combinations of REQ_FLUSH and FUA.  If a
      device has write cache and can flush it, it should set REQ_FLUSH.  If
      the device can handle FUA writes, it should also set REQ_FUA.
      All blk_queue_ordered() users are converted.
      * ORDERED_DRAIN is mapped to 0 which is the default value.
      * ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Acked-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Nick Piggin <npiggin@kernel.dk>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
      Cc: Chris Wright <chrisw@sous-sol.org>
      Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
      Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Alasdair G Kergon <agk@redhat.com>
      Cc: Pierre Ossman <drzeus@drzeus.cx>
      Cc: Stefan Weinhuber <wein@de.ibm.com>
      Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
  25. 07 Aug, 2010 1 commit
  26. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit 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.
      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
      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
      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
      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: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
  27. 15 Mar, 2010 1 commit
  28. 26 Feb, 2010 5 commits
  29. 11 Jan, 2010 3 commits
  30. 29 Dec, 2009 1 commit