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  1. 19 5月, 2009 2 次提交
  3. 11 5月, 2009 1 次提交
    • T
      block: hide request sector and data_len · a2dec7b3
      由 Tejun Heo 提交于 
      Block low level drivers for some reason have been pretty good at
abusing block layer API.  Especially struct request's fields tend to
get violated in all possible ways.  Make it clear that low level
drivers MUST NOT access or manipulate rq->sector and rq->data_len
directly by prefixing them with double underscores.

This change is also necessary to break build of out-of-tree codes
which assume the previous block API where internal fields can be
manipulated and rq->data_len carries residual count on completion.

[ Impact: hide internal fields, block API change ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      a2dec7b3
  5. 28 4月, 2009 1 次提交
    • T
      block: kill rq->data · 731ec497
      由 Tejun Heo 提交于 
      Now that all block request data transfer is done via bio, rq->data
isn't used.  Kill it.

While at it, make the roles of rq->special and buffer clear.

[ Impact: drop now unncessary field from struct request ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Boaz Harrosh <bharrosh@panasas.com>
      731ec497
  7. 03 1月, 2009 2 次提交
  9. 03 12月, 2008 1 次提交
  11. 18 11月, 2008 1 次提交
  13. 09 10月, 2008 5 次提交
  15. 27 7月, 2008 1 次提交
  17. 04 7月, 2008 1 次提交
  19. 03 7月, 2008 1 次提交
  21. 29 4月, 2008 1 次提交
  23. 21 4月, 2008 2 次提交
    • F
      block: move the padding adjustment to blk_rq_map_sg · f18573ab
      由 FUJITA Tomonori 提交于 
      blk_rq_map_user adjusts bi_size of the last bio. It breaks the rule
that req->data_len (the true data length) is equal to sum(bio). It
broke the scsi command completion code.

commit e97a294e was introduced to fix
the above issue. However, the partial completion code doesn't work
with it. The commit is also a layer violation (scsi mid-layer should
not know about the block layer's padding).

This patch moves the padding adjustment to blk_rq_map_sg (suggested by
James). The padding works like the drain buffer. This patch breaks the
rule that req->data_len is equal to sum(sg), however, the drain buffer
already broke it. So this patch just restores the rule that
req->data_len is equal to sub(bio) without breaking anything new.

Now when a low level driver needs padding, blk_rq_map_user and
blk_rq_map_user_iov guarantee there's enough room for padding.
blk_rq_map_sg can safely extend the last entry of a scatter list.

blk_rq_map_sg must extend the last entry of a scatter list only for a
request that got through bio_copy_user_iov. This patches introduces
new REQ_COPY_USER flag.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      f18573ab
    • F
      block: add bio_copy_user_iov support to blk_rq_map_user_iov · afdc1a78
      由 FUJITA Tomonori 提交于 
      With this patch, blk_rq_map_user_iov uses bio_copy_user_iov when a low
level driver needs padding or a buffer in sg_iovec isn't aligned. That
is, it uses temporary kernel buffers instead of mapping user pages
directly.

When a LLD needs padding, later blk_rq_map_sg needs to extend the last
entry of a scatter list. bio_copy_user_iov guarantees that there is
enough space for padding by using temporary kernel buffers instead of
user pages.

blk_rq_map_user_iov needs buffers in sg_iovec to be aligned. The
comment in blk_rq_map_user_iov indicates that drivers/scsi/sg.c also
needs buffers in sg_iovec to be aligned. Actually, drivers/scsi/sg.c
works with unaligned buffers in sg_iovec (it always uses temporary
kernel buffers).
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      afdc1a78
  25. 04 3月, 2008 4 次提交
  27. 19 2月, 2008 3 次提交
    • T
      block: add request->raw_data_len · 6b00769f
      由 Tejun Heo 提交于 
      With padding and draining moved into it, block layer now may extend
requests as directed by queue parameters, so now a request has two
sizes - the original request size and the extended size which matches
the size of area pointed to by bios and later by sgs.  The latter size
is what lower layers are primarily interested in when allocating,
filling up DMA tables and setting up the controller.

Both padding and draining extend the data area to accomodate
controller characteristics.  As any controller which speaks SCSI can
handle underflows, feeding larger data area is safe.

So, this patch makes the primary data length field, request->data_len,
indicate the size of full data area and add a separate length field,
request->raw_data_len, for the unmodified request size.  The latter is
used to report to higher layer (userland) and where the original
request size should be fed to the controller or device.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      6b00769f
    • T
      block: update bio according to DMA alignment padding · 40b01b9b
      由 Tejun Heo 提交于 
      DMA start address and transfer size alignment for PC requests are
achieved using bio_copy_user() instead of bio_map_user().  This works
because bio_copy_user() always uses full pages and block DMA alignment
isn't allowed to go over PAGE_SIZE.

However, the implementation didn't update the last bio of the request
to make this padding visible to lower layers.  This patch makes
blk_rq_map_user() extend the last bio such that it includes the
padding area and the size of area pointed to by the request is
properly aligned.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      40b01b9b
    • J
      block: make blk_rq_map_user() clear ->bio if it unmaps it · 84e9e03c
      由 Jens Axboe 提交于 
      That way the interface is symmetric, and calling blk_rq_unmap_user()
on the request wont oops.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      84e9e03c
  29. 01 2月, 2008 1 次提交
  31. 30 1月, 2008 1 次提交