1. 11 May, 2009 2 commits
    • Tejun Heo's avatar
      block: add rq->resid_len · c3a4d78c
      Tejun Heo authored
      rq->data_len served two purposes - the length of data buffer on issue
      and the residual count on completion.  This duality creates some
      headaches.
      
      First of all, block layer and low level drivers can't really determine
      what rq->data_len contains while a request is executing.  It could be
      the total request length or it coulde be anything else one of the
      lower layers is using to keep track of residual count.  This
      complicates things because blk_rq_bytes() and thus
      [__]blk_end_request_all() relies on rq->data_len for PC commands.
      Drivers which want to report residual count should first cache the
      total request length, update rq->data_len and then complete the
      request with the cached data length.
      
      Secondly, it makes requests default to reporting full residual count,
      ie. reporting that no data transfer occurred.  The residual count is
      an exception not the norm; however, the driver should clear
      rq->data_len to zero to signify the normal cases while leaving it
      alone means no data transfer occurred at all.  This reverse default
      behavior complicates code unnecessarily and renders block PC on some
      drivers (ide-tape/floppy) unuseable.
      
      This patch adds rq->resid_len which is used only for residual count.
      
      While at it, remove now unnecessasry blk_rq_bytes() caching in
      ide_pc_intr() as rq->data_len is not changed anymore.
      
      Boaz	: spotted missing conversion in osd
      Sergei	: spotted too early conversion to blk_rq_bytes() in ide-tape
      
      [ Impact: cleanup residual count handling, report 0 resid by default ]
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      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: Mike Miller <mike.miller@hp.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: Doug Gilbert <dgilbert@interlog.com>
      Cc: Mike Miller <mike.miller@hp.com>
      Cc: Eric Moore <Eric.Moore@lsi.com>
      Cc: Darrick J. Wong <djwong@us.ibm.com>
      Cc: Pete Zaitcev <zaitcev@redhat.com>
      Cc: Boaz Harrosh <bharrosh@panasas.com>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      c3a4d78c
    • Tejun Heo's avatar
      ide-tape: don't initialize rq->sector for rw requests · 9720aef2
      Tejun Heo authored
      rq->sector is set to the tape->first_frame but it's never actually
      used and not even in the correct unit (512 byte sectors).  Don't set
      it.
      
      [ Impact: cleanup ]
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Acked-by: default avatarBorislav Petkov <petkovbb@gmail.com>
      Acked-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      9720aef2
  2. 27 Apr, 2009 13 commits
    • Tejun Heo's avatar
      ide-atapi: kill unused fields and callbacks · 29d1a437
      Tejun Heo authored
      Impact: remove fields and code paths which are no longer necessary
      
      Now that ide-tape uses standard mechanisms to transfer data, special
      case handling for bh handling can be dropped from ide-atapi.  Drop the
      followings.
      
      * pc->cur_pos, b_count, bh and b_data
      * drive->pc_update_buffers() and pc_io_buffers().
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      29d1a437
    • Tejun Heo's avatar
      ide-tape: simplify read/write functions · 4344d07f
      Tejun Heo authored
      Impact: cleanup
      
      idetape_chrdev_read/write() functions are unnecessarily complex when
      everything can be handled in a single loop.  Collapse
      idetape_add_chrdev_read/write_request() into the rw functions and
      simplify the implementation.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      4344d07f
    • Tejun Heo's avatar
      ide-tape: use byte size instead of sectors on rw issue functions · 71294cf9
      Tejun Heo authored
      Impact: cleanup
      
      Byte size is what most issue functions deal with, make
      idetape_queue_rw_tail() and its wrappers take byte size instead of
      sector counts.  idetape_chrdev_read() and write() functions are
      converted to use tape->buffer_size instead of ctl from tape->cap.
      
      This cleans up code a little bit and will ease the next r/w
      reimplementation.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      71294cf9
    • Tejun Heo's avatar
      ide-tape: unify r/w init paths · 3596b664
      Tejun Heo authored
      Impact: cleanup
      
      Read and write init paths are almost identical.  Unify them into
      idetape_init_rw().
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      3596b664
    • Tejun Heo's avatar
      ide-tape: kill idetape_bh · 6cf3d545
      Tejun Heo authored
      Impact: kill now unnecessary idetape_bh
      
      With everything using standard mechanisms, there is no need for
      idetape_bh anymore.  Kill it and use tape->buf, cur and valid to
      describe data buffer instead.
      
      Changes worth mentioning are...
      
      * idetape_queue_rq_tail() now always queue tape->buf and and adjusts
        buffer state properly before completion.
      
      * idetape_pad_zeros() clears the buffer only once.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      6cf3d545
    • Tejun Heo's avatar
      ide-tape: use standard data transfer mechanism · e998f30b
      Tejun Heo authored
      Impact: use standard way to transfer data
      
      ide-tape uses rq in an interesting way.  For r/w requests, rq->special
      is used to carry a private buffer management structure idetape_bh and
      rq->nr_sectors and current_nr_sectors are initialized to the number of
      idetape blocks which isn't necessary 512 bytes.  Also,
      rq->current_nr_sectors is used to report back the residual count in
      units of idetape blocks.
      
      This peculiarity taxes both block layer and ide.  ide-atapi has
      different paths and hooks to accomodate it and what a rq means becomes
      quite confusing and making changes at the block layer becomes quite
      difficult and error-prone.
      
      This patch makes ide-tape use bio instead.  With the previous patch,
      ide-tape currently is using single contiguos buffer so replacing it
      isn't difficult.  Data buffer is mapped into bio using
      blk_rq_map_kern() in idetape_queue_rw_tail().  idetape_io_buffers()
      and idetape_update_buffers() are dropped and pc->bh is set to null to
      tell ide-atapi to use standard data transfer mechanism and idetape_bh
      byte counts are updated by the issuer on completion using the residual
      count.
      
      This change also nicely removes the FIXME in ide_pc_intr() where
      ide-tape rqs need to be completed using ide_rq_bytes() instead of
      blk_rq_bytes() (although this didn't really matter as the request
      didn't have bio).
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      e998f30b
    • Tejun Heo's avatar
      ide-tape: use single continuous buffer · 7b13354e
      Tejun Heo authored
      Impact: simpler buffer allocation and handling, kills OOM, fix DMA transfers
      
      ide-tape has its own multiple buffer mechanism using struct
      idetape_bh.  It allocates buffer with decreasing order-of-two
      allocations so that it results in minimum number of segments.
      However, the implementation is quite complex and works in a way that
      no other block or ide driver works necessitating a lot of special case
      handling.
      
      The benefit this complex allocation scheme brings is questionable as
      PIO or DMA the number of segments (16 maximum) doesn't make any
      noticeable difference and it also doesn't negate the need for multiple
      order allocation which can fail under memory pressure or high
      fragmentation although it does lower the highest order necessary by
      one when the buffer size isn't power of two.
      
      As the first step to remove the custom buffer management, this patch
      makes ide-tape allocate single continous buffer.  The maximum order is
      four.  I doubt the change would cause any trouble but if it ever
      matters, it should be converted to regular sg mechanism like everyone
      else and even in that case dropping custom buffer handling and moving
      to standard mechanism first make sense as an intermediate step.
      
      This patch makes the first bh to contain the whole buffer and drops
      multi bh handling code.  Following patches will make further changes.
      
      This patch has the side effect of killing OOM triggered by allocation
      path and fixing DMA transfers.  Previously, bug in alloc path
      triggered OOM on command issue and commands were passed to DMA engine
      without DMA-mapping all the segments.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      7b13354e
    • Tejun Heo's avatar
      ide-atapi,tape,floppy: allow ->pc_callback() to change rq->data_len · eb6a61bb
      Tejun Heo authored
      Impact: allow residual count implementation in ->pc_callback()
      
      rq->data_len has two duties - carrying the number of input bytes on
      issue and carrying residual count back to the issuer on completion.
      ide-atapi completion callback ->pc_callback() is the right place to do
      this but currently ide-atapi depends on rq->data_len carrying the
      original request size after calling ->pc_callback() to complete the pc
      request.
      
      This patch makes ide_pc_intr(), ide_tape_issue_pc() and
      ide_floppy_issue_pc() cache length to complete before calling
      ->pc_callback() so that it can modify rq->data_len as necessary.
      
      Note: As using rq->data_len for two purposes can make cases like this
            incorrect in subtle ways, future changes will introduce separate
            field for residual count.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      eb6a61bb
    • Tejun Heo's avatar
      ide-tape,floppy: fix failed command completion after request sense · 08f370f0
      Tejun Heo authored
      Impact: fix infinite retry loop
      
      After a command failed, ide-tape and floppy inserts REQUEST_SENSE in
      front of the failed command and according to the result, sets
      pc->retries, flags and errors.  After REQUEST_SENSE is complete, the
      failed command is again at the front of the queue and if the verdict
      was to terminate the request, the issue functions tries to complete it
      directly by calling drive->pc_callback() and returning ide_stopped.
      
      However, drive->pc_callback() doesn't complete a request.  It only
      prepares for completion of the request.  As a result, this creates an
      infinite loop where the failed request is retried perpetually.
      
      Fix it by actually ending the request by calling ide_complete_rq().
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      08f370f0
    • Tejun Heo's avatar
      ide-cd,atapi: use bio for internal commands · 02e7cf8f
      Tejun Heo authored
      Impact: unify request data buffer handling
      
      rq->data is used mostly to pass kernel buffer through request queue
      without using bio.  There are only a couple of places which still do
      this in kernel and converting to bio isn't difficult.
      
      This patch converts ide-cd and atapi to use bio instead of rq->data
      for request sense and internal pc commands.  With previous change to
      unify sense request handling, this is relatively easily achieved by
      adding blk_rq_map_kern() during sense_rq prep and PC issue.
      
      If blk_rq_map_kern() fails for sense, the error is deferred till sense
      issue and aborts the failed command which triggered the sense.  Note
      that this is a slim possibility as sense prep is done on each command
      issue, so for the above condition to actually trigger, all preps since
      the last sense issue till the issue of the request which would require
      a sense should fail.
      
      * do_request functions might sleep now.  This should be okay as ide
        request_fn - do_ide_request() - is invoked only from make_request
        and plug work.  Make sure this is the case by adding might_sleep()
        to do_ide_request().
      
      * Functions which access the read sense data before the sense request
        is complete now should access bio_data(sense_rq->bio) as the sense
        buffer might have been copied during blk_rq_map_kern().
      
      * ide-tape updated to map sg.
      
      * cdrom_do_block_pc() now doesn't have to deal with REQ_TYPE_ATA_PC
        special case.  Simplified.
      
      * tp_ops->output/input_data path dropped from ide_pc_intr().
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      02e7cf8f
    • Borislav Petkov's avatar
      ide-atapi: convert ide-{floppy,tape} to using preallocated sense buffer · 06875320
      Borislav Petkov authored
      Since we're issuing REQ_TYPE_SENSE now we need to allow those types of
      rqs in the ->do_request callbacks. As a future improvement, sense_len
      assignment might be unified across all ATAPI devices. Borislav to
      check with specs and test.
      
      As a result, get rid of ide_queue_pc_head() and
      drive->request_sense_rq.
      
      tj: * Init request sense ide_atapi_pc from sense request.  In the
            longer timer, it would probably better to fold
            ide_create_request_sense_cmd() into its only current user -
            ide_floppy_get_format_progress().
      
          * ide_retry_pc() no longer takes @disk.
      
      CC: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      CC: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
      Signed-off-by: default avatarBorislav Petkov <petkovbb@gmail.com>
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      06875320
    • Tejun Heo's avatar
      ide-atapi: don't abuse rq->buffer · ac0b0113
      Tejun Heo authored
      Impact: rq->buffer usage cleanup
      
      ide-atapi uses rq->buffer as private opaque value for internal special
      requests.  rq->special isn't used for these cases (the only case where
      rq->special is used is for ide-tape rw requests).  Use rq->special
      instead.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Jens Axboe <axboe@kernel.dk>
      ac0b0113
    • Tejun Heo's avatar
      ide-tape: remove back-to-back REQUEST_SENSE detection · 0de57fb9
      Tejun Heo authored
      Impact: fix an oops which always triggers
      
      ide_tape_issue_pc() assumed drive->pc isn't NULL on invocation when
      checking for back-to-back request sense issues but drive->pc can be
      NULL and even when it's not NULL, it's not safe to dereference it once
      the previous command is complete because pc could have been freed or
      was on stack.  Kill back-to-back REQUEST_SENSE detection.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      0de57fb9
  3. 31 Mar, 2009 2 commits
    • Bartlomiej Zolnierkiewicz's avatar
      ide-{floppy,tape}: fix padding for PIO transfers · d93bc452
      Bartlomiej Zolnierkiewicz authored
      * Return number of bytes left to transfer from idetape_{in,out}put_buffers()
        and number of bytes done from ide_tape_io_buffers().
      
      * Fix padding for PIO transfers in ide_pc_intr() so read/write buffers are
        always completely processed and then the transfer is padded if necessary.
      
      * Remove invalid error messages.
      
      * Remove now superfluous padding from ide{_io_buffers,tape_input_buffers}().
      
      While at it:
      
      * Set pc->bh to NULL in idetape_input_buffers() after all bh-s are done.
      
      * Cache !!(pc->flags & PC_FLAG_WRITING) in local variable in ide_pc_intr().
      
      Cc: Borislav Petkov <petkovbb@gmail.com>
      Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      d93bc452
    • Bartlomiej Zolnierkiewicz's avatar
      ide: decrease size of ->pc_buf field in struct ide_atapi_pc · 41fa9f86
      Bartlomiej Zolnierkiewicz authored
      struct ide_atapi_pc is often allocated on the stack and size of ->pc_buf
      size is 256 bytes.  However since only ide_floppy_create_read_capacity_cmd()
      and idetape_create_inquiry_cmd() require such size allocate buffers for
      these pc-s explicitely and decrease ->pc_buf size to 64 bytes.
      
      Cc: Borislav Petkov <petkovbb@gmail.com>
      Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      41fa9f86
  4. 27 Mar, 2009 12 commits
  5. 05 Mar, 2009 1 commit
    • Hannes Eder's avatar
      ide: NULL noise: drivers/ide/ide-*.c · 71bfc7a7
      Hannes Eder authored
      Fix this sparse warnings:
        drivers/ide/ide-disk_proc.c:130:11: warning: Using plain integer as NULL pointer
        drivers/ide/ide-floppy_proc.c:32:11: warning: Using plain integer as NULL pointer
        drivers/ide/ide-proc.c:234:11: warning: Using plain integer as NULL pointer
        drivers/ide/ide-tape.c:2141:11: warning: Using plain integer as NULL pointer
      Signed-off-by: default avatarHannes Eder <hannes@hanneseder.net>
      Cc: trivial@kernel.org
      Cc: kernel-janitors@vger.kernel.org
      Cc: Al Viro <viro@ZenIV.linux.org.uk>
      Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      71bfc7a7
  6. 25 Feb, 2009 1 commit
  7. 06 Jan, 2009 3 commits
  8. 02 Jan, 2009 2 commits
  9. 21 Oct, 2008 3 commits
    • Al Viro's avatar
      [PATCH] switch ide-tape · a4600f81
      Al Viro authored
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      a4600f81
    • Al Viro's avatar
      [PATCH] beginning of methods conversion · d4430d62
      Al Viro authored
      To keep the size of changesets sane we split the switch by drivers;
      to keep the damn thing bisectable we do the following:
      	1) rename the affected methods, add ones with correct
      prototypes, make (few) callers handle both.  That's this changeset.
      	2) for each driver convert to new methods.  *ALL* drivers
      are converted in this series.
      	3) kill the old (renamed) methods.
      
      Note that it _is_ a flagday; all in-tree drivers are converted and by the
      end of this series no trace of old methods remain.  The only reason why
      we do that this way is to keep the damn thing bisectable and allow per-driver
      debugging if anything goes wrong.
      
      New methods:
      	open(bdev, mode)
      	release(disk, mode)
      	ioctl(bdev, mode, cmd, arg)		/* Called without BKL */
      	compat_ioctl(bdev, mode, cmd, arg)
      	locked_ioctl(bdev, mode, cmd, arg)	/* Called with BKL, legacy */
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      d4430d62
    • Al Viro's avatar
      1bddd9e6
  10. 17 Oct, 2008 1 commit