1. 22 May, 2009 1 commit
  2. 11 May, 2009 3 commits
    • Tejun Heo's avatar
      block: implement and enforce request peek/start/fetch · 9934c8c0
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
      Cc: Mike Miller <mike.miller@hp.com>
      Cc: unsik Kim <donari75@gmail.com>
      Cc: Paul Clements <paul.clements@steeleye.com>
      Cc: Tim Waugh <tim@cyberelk.net>
      Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Laurent Vivier <Laurent@lvivier.info>
      Cc: Jeff Garzik <jgarzik@pobox.com>
      Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
      Cc: Grant Likely <grant.likely@secretlab.ca>
      Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      Cc: Borislav Petkov <petkovbb@googlemail.com>
      Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
      Cc: Alex Dubov <oakad@yahoo.com>
      Cc: Pierre Ossman <drzeus@drzeus.cx>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
      Cc: Stefan Weinhuber <wein@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Pete Zaitcev <zaitcev@redhat.com>
      Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      9934c8c0
    • Tejun Heo's avatar
      hd: dequeue and track in-flight request · 8a12c4a4
      Tejun Heo authored
      hd has at most single request in flight.  Till now, whenever it needs
      to access the in-flight request it called elv_next_request().  This
      patch makes hd track the in-flight request directly and dequeue it
      when processing starts.  The added complexity is minimal and this will
      help future block layer changes.
      
      [ Impact: dequeue in-flight request, one elv_next_request() per request ]
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      8a12c4a4
    • Tejun Heo's avatar
      block: convert to pos and nr_sectors accessors · 83096ebf
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Acked-by: default avatarGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
      Tested-by: default avatarGrant Likely <grant.likely@secretlab.ca>
      Acked-by: default avatarGrant Likely <grant.likely@secretlab.ca>
      Tested-by: default avatarAdrian McMenamin <adrian@mcmen.demon.co.uk>
      Acked-by: default avatarAdrian McMenamin <adrian@mcmen.demon.co.uk>
      Acked-by: default avatarMike Miller <mike.miller@hp.com>
      Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
      Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      Cc: Borislav Petkov <petkovbb@googlemail.com>
      Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
      Cc: Eric Moore <Eric.Moore@lsi.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
      Cc: Pete Zaitcev <zaitcev@redhat.com>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Paul Clements <paul.clements@steeleye.com>
      Cc: Tim Waugh <tim@cyberelk.net>
      Cc: Jeff Garzik <jgarzik@pobox.com>
      Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
      Cc: Alex Dubov <oakad@yahoo.com>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Dario Ballabio <ballabio_dario@emc.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: unsik Kim <donari75@gmail.com>
      Cc: Laurent Vivier <Laurent@lvivier.info>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      83096ebf
  3. 28 Apr, 2009 2 commits
    • Tejun Heo's avatar
      hd: fix locking · 01919442
      Tejun Heo authored
      hd dance around local irq and HD_IRQ enable without achieving much.
      It ends up transferring data from irq handler with both local irq and
      HD_IRQ disabled.  The only place it actually does something is while
      transferring the first block of a request which it does with HD_IRQ
      disabled but local irq enabled.
      
      Unfortunately, the dancing is horribly broken from locking POV.  IRQ
      and timeout handlers access block queue without grabbing the queue
      lock and running the driver in SMP configuration crashes the whole
      machine pretty quickly.
      
      Remove meaningless irq enable/disable dancing and add proper locking
      in issue, irq and timeout paths.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      01919442
    • Tejun Heo's avatar
      hd: clean up request completion paths · e091eb67
      Tejun Heo authored
      hd read/write_intr() functions manually manipulate request to
      incrementally complete it, which block layer already supports.  Simply
      use block layer completion routines instead of manual partial
      completion.
      
      While at it, clear unnecessary elv_next_request() check at the tail of
      read_intr().  This also makes read and write_intr() more consistent.
      
      [ Impact: cleanup ]
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      e091eb67
  4. 27 Apr, 2009 2 commits
    • Tejun Heo's avatar
      block: replace end_request() with [__]blk_end_request_cur() · f06d9a2b
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Acked-by: default avatarJoerg Dorchain <joerg@dorchain.net>
      Acked-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      Acked-by: default avatarGrant Likely <grant.likely@secretlab.ca>
      Acked-by: default avatarLaurent Vivier <Laurent@lvivier.info>
      Cc: Tim Waugh <tim@cyberelk.net>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
      Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Pete Zaitcev <zaitcev@redhat.com>
      Cc: unsik Kim <donari75@gmail.com>
      f06d9a2b
    • Tejun Heo's avatar
      hd: fix locking · e93b9fb7
      Tejun Heo authored
      hd dance around local irq and HD_IRQ enable without achieving much.
      It ends up transferring data from irq handler with both local irq and
      HD_IRQ disabled.  The only place it actually does something is while
      transferring the first block of a request which it does with HD_IRQ
      disabled but local irq enabled.
      
      Unfortunately, the dancing is horribly broken from locking POV.  IRQ
      and timeout handlers access block queue without grabbing the queue
      lock and running the driver in SMP configuration crashes the whole
      machine pretty quickly.
      
      Remove meaningless irq enable/disable dancing and add proper locking
      in issue, irq and timeout paths.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      e93b9fb7
  5. 01 Apr, 2009 1 commit
  6. 10 Oct, 2008 1 commit
  7. 16 Jul, 2008 3 commits
  8. 26 Apr, 2008 1 commit
  9. 05 Feb, 2008 1 commit
  10. 24 Jul, 2007 1 commit
  11. 12 Jul, 2007 1 commit
  12. 10 Jul, 2007 1 commit
    • Boaz Harrosh's avatar
      [PATCH] fix request->cmd == INT cases · e654bc43
      Boaz Harrosh authored
       - I have unearthed very old bugs in stale drivers that still
         used request->cmd as a READ|WRITE int
       - This patch is maybe a proof that these drivers have not been
         used for a long time. Should they be removed completely?
      
      Drivers that currently do not work for sure:
       drivers/acorn/block/fd1772.c |    2 +-
       drivers/acorn/block/mfmhd.c  |    8 ++++----
       drivers/cdrom/aztcd.c        |    2 +-
       drivers/cdrom/cm206.c        |    2 +-
       drivers/cdrom/gscd.c         |    2 +-
       drivers/cdrom/mcdx.c         |    2 +-
       drivers/cdrom/optcd.c        |    2 +-
       drivers/cdrom/sjcd.c         |    2 +-
      
      Drivers with cosmetic fixes only:
        b/drivers/block/amiflop.c
        b/drivers/block/nbd.c
        b/drivers/ide/legacy/hd.c
      Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      e654bc43
  13. 09 Jul, 2007 1 commit
  14. 14 Nov, 2006 1 commit
  15. 05 Oct, 2006 1 commit
    • David Howells's avatar
      IRQ: Maintain regs pointer globally rather than passing to IRQ handlers · 7d12e780
      David Howells authored
      Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
      of passing regs around manually through all ~1800 interrupt handlers in the
      Linux kernel.
      
      The regs pointer is used in few places, but it potentially costs both stack
      space and code to pass it around.  On the FRV arch, removing the regs parameter
      from all the genirq function results in a 20% speed up of the IRQ exit path
      (ie: from leaving timer_interrupt() to leaving do_IRQ()).
      
      Where appropriate, an arch may override the generic storage facility and do
      something different with the variable.  On FRV, for instance, the address is
      maintained in GR28 at all times inside the kernel as part of general exception
      handling.
      
      Having looked over the code, it appears that the parameter may be handed down
      through up to twenty or so layers of functions.  Consider a USB character
      device attached to a USB hub, attached to a USB controller that posts its
      interrupts through a cascaded auxiliary interrupt controller.  A character
      device driver may want to pass regs to the sysrq handler through the input
      layer which adds another few layers of parameter passing.
      
      I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
      main part of the code on FRV and i386, though I can't test most of the drivers.
      I've also done partial conversion for powerpc and MIPS - these at least compile
      with minimal configurations.
      
      This will affect all archs.  Mostly the changes should be relatively easy.
      Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
      
      	struct pt_regs *old_regs = set_irq_regs(regs);
      
      And put the old one back at the end:
      
      	set_irq_regs(old_regs);
      
      Don't pass regs through to generic_handle_irq() or __do_IRQ().
      
      In timer_interrupt(), this sort of change will be necessary:
      
      	-	update_process_times(user_mode(regs));
      	-	profile_tick(CPU_PROFILING, regs);
      	+	update_process_times(user_mode(get_irq_regs()));
      	+	profile_tick(CPU_PROFILING);
      
      I'd like to move update_process_times()'s use of get_irq_regs() into itself,
      except that i386, alone of the archs, uses something other than user_mode().
      
      Some notes on the interrupt handling in the drivers:
      
       (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
           the input_dev struct.
      
       (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
           something different depending on whether it's been supplied with a regs
           pointer or not.
      
       (*) Various IRQ handler function pointers have been moved to type
           irq_handler_t.
      Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
      (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
      7d12e780
  16. 30 Sep, 2006 1 commit
    • 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
  17. 02 Jul, 2006 1 commit
  18. 08 Jan, 2006 1 commit
    • Christoph Hellwig's avatar
      [PATCH] Add block_device_operations.getgeo block device method · a885c8c4
      Christoph Hellwig authored
      HDIO_GETGEO is implemented in most block drivers, and all of them have to
      duplicate the code to copy the structure to userspace, as well as getting
      the start sector.  This patch moves that to common code [1] and adds a
      ->getgeo method to fill out the raw kernel hd_geometry structure.  For many
      drivers this means ->ioctl can go away now.
      
      [1] the s390 block drivers are odd in this respect.  xpram sets ->start
          to 4 always which seems more than odd, and the dasd driver shifts
          the start offset around, probably because of it's non-standard
          sector size.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Cc: Jens Axboe <axboe@suse.de>
      Cc: <mike.miller@hp.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
      Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
      Cc: Neil Brown <neilb@cse.unsw.edu.au>
      Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: James Bottomley <James.Bottomley@steeleye.com>
      Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a885c8c4
  19. 30 Jun, 2005 1 commit
  20. 16 Apr, 2005 2 commits