1. 09 Nov, 2015 1 commit
  2. 23 Jan, 2015 1 commit
    • Shaohua Li's avatar
      block: support different tag allocation policy · ee1b6f7a
      Shaohua Li authored
      The libata tag allocation is using a round-robin policy. Next patch will
      make libata use block generic tag allocation, so let's add a policy to
      tag allocation.
      
      Currently two policies: FIFO (default) and round-robin.
      
      Cc: Jens Axboe <axboe@fb.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Christoph Hellwig <hch@infradead.org>
      Signed-off-by: default avatarShaohua Li <shli@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      ee1b6f7a
  3. 04 Dec, 2014 4 commits
  4. 12 Nov, 2014 6 commits
  5. 28 Oct, 2014 1 commit
  6. 22 Sep, 2014 1 commit
  7. 19 Sep, 2014 1 commit
  8. 15 Sep, 2014 1 commit
  9. 25 Jul, 2014 1 commit
    • Christoph Hellwig's avatar
      scsi: add support for a blk-mq based I/O path. · d285203c
      Christoph Hellwig authored
      This patch adds support for an alternate I/O path in the scsi midlayer
      which uses the blk-mq infrastructure instead of the legacy request code.
      
      Use of blk-mq is fully transparent to drivers, although for now a host
      template field is provided to opt out of blk-mq usage in case any unforseen
      incompatibilities arise.
      
      In general replacing the legacy request code with blk-mq is a simple and
      mostly mechanical transformation.  The biggest exception is the new code
      that deals with the fact the I/O submissions in blk-mq must happen from
      process context, which slightly complicates the I/O completion handler.
      The second biggest differences is that blk-mq is build around the concept
      of preallocated requests that also include driver specific data, which
      in SCSI context means the scsi_cmnd structure.  This completely avoids
      dynamic memory allocations for the fast path through I/O submission.
      
      Due the preallocated requests the MQ code path exclusively uses the
      host-wide shared tag allocator instead of a per-LUN one.  This only
      affects drivers actually using the block layer provided tag allocator
      instead of their own.  Unlike the old path blk-mq always provides a tag,
      although drivers don't have to use it.
      
      For now the blk-mq path is disable by defauly and must be enabled using
      the "use_blk_mq" module parameter.  Once the remaining work in the block
      layer to make blk-mq more suitable for slow devices is complete I hope
      to make it the default and eventually even remove the old code path.
      
      Based on the earlier scsi-mq prototype by Nicholas Bellinger.
      
      Thanks to Bart Van Assche and Robert Elliot for testing, benchmarking and
      various sugestions and code contributions.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Reviewed-by: default avatarWebb Scales <webbnh@hp.com>
      Acked-by: default avatarJens Axboe <axboe@kernel.dk>
      Tested-by: default avatarBart Van Assche <bvanassche@acm.org>
      Tested-by: default avatarRobert Elliott <elliott@hp.com>
      d285203c
  10. 27 May, 2011 1 commit
  11. 24 May, 2011 1 commit
  12. 10 Sep, 2010 1 commit
    • Tejun Heo's avatar
      block: remove spurious uses of REQ_HARDBARRIER · 9cbbdca4
      Tejun Heo authored
      REQ_HARDBARRIER is deprecated.  Remove spurious uses in the following
      users.  Please note that other than osdblk, all other uses were
      already spurious before deprecation.
      
      * osdblk: osdblk_rq_fn() won't receive any request with
        REQ_HARDBARRIER set.  Remove the test for it.
      
      * pktcdvd: use of REQ_HARDBARRIER in pkt_generic_packet() doesn't mean
        anything.  Removed.
      
      * aic7xxx_old: Setting MSG_ORDERED_Q_TAG on REQ_HARDBARRIER is
        spurious.  Removed.
      
      * sas_scsi_host: Setting TASK_ATTR_ORDERED on REQ_HARDBARRIER is
        spurious.  Removed.
      
      * scsi_tcq: The ordered tag path wasn't being used anyway.  Removed.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Acked-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      Cc: James Bottomley <James.Bottomley@suse.de>
      Cc: Peter Osterlund <petero2@telia.com>
      Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
      9cbbdca4
  13. 27 Oct, 2008 1 commit
  14. 04 Oct, 2006 1 commit
  15. 30 Sep, 2006 2 commits
    • David Howells's avatar
      [PATCH] BLOCK: Make it possible to disable the block layer [try #6] · 9361401e
      David Howells authored
      Make it possible to disable the block layer.  Not all embedded devices require
      it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
      the block layer to be present.
      
      This patch does the following:
      
       (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
           support.
      
       (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
           an item that uses the block layer.  This includes:
      
           (*) Block I/O tracing.
      
           (*) Disk partition code.
      
           (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
      
           (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
           	 block layer to do scheduling.  Some drivers that use SCSI facilities -
           	 such as USB storage - end up disabled indirectly from this.
      
           (*) Various block-based device drivers, such as IDE and the old CDROM
           	 drivers.
      
           (*) MTD blockdev handling and FTL.
      
           (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
           	 taking a leaf out of JFFS2's book.
      
       (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
           linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
           however, still used in places, and so is still available.
      
       (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
           parts of linux/fs.h.
      
       (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
      
       (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
      
       (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
           is not enabled.
      
       (*) fs/no-block.c is created to hold out-of-line stubs and things that are
           required when CONFIG_BLOCK is not set:
      
           (*) Default blockdev file operations (to give error ENODEV on opening).
      
       (*) Makes some /proc changes:
      
           (*) /proc/devices does not list any blockdevs.
      
           (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
      
       (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
      
       (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
           given command other than Q_SYNC or if a special device is specified.
      
       (*) In init/do_mounts.c, no reference is made to the blockdev routines if
           CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.
      
       (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
           error ENOSYS by way of cond_syscall if so).
      
       (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
           CONFIG_BLOCK is not set, since they can't then happen.
      Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      9361401e
    • Jens Axboe's avatar
      [PATCH] Split struct request ->flags into two parts · 4aff5e23
      Jens Axboe authored
      Right now ->flags is a bit of a mess: some are request types, and
      others are just modifiers. Clean this up by splitting it into
      ->cmd_type and ->cmd_flags. This allows introduction of generic
      Linux block message types, useful for sending generic Linux commands
      to block devices.
      Signed-off-by: default avatarJens Axboe <axboe@suse.de>
      4aff5e23
  16. 02 Sep, 2006 1 commit
  17. 31 Aug, 2006 1 commit
  18. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      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!
      1da177e4