linux.git/block/blk-map.c, branch v2.6.27

block/blk-map.c: use the new object_is_on_stack() helper

2008-07-26T19:00:02+00:00

Signed-off-by: FUJITA Tomonori 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Thomas Bogendoerfer 
Cc: Tejun Heo 
Cc: Jens Axboe 
Cc: James Bottomley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block: blk_rq_map_kern uses the bounce buffers for stack buffers

2008-07-04T07:52:13+00:00

blk_rq_map_kern is used for kernel internal I/Os. Some callers use
this function with stack buffers but DMA to/from the stack buffers
leads to memory corruption on a non-coherent platform.

This patch make blk_rq_map_kern uses the bounce buffers if a caller
passes a stack buffer (on the all platforms for simplicity).

Signed-off-by: FUJITA Tomonori 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Thomas Bogendoerfer 
Cc: Tejun Heo 
Cc: James Bottomley 
Signed-off-by: Andrew Morton 
Signed-off-by: Jens Axboe

block: add bounce support to blk_rq_map_user_iov

2008-07-03T11:21:14+00:00

blk_rq_map_user_iov can't handle the bounce buffer (it means that the
bio_map_user_iov path doesn't work with a LLD that needs GFP_DMA).

This patch fixes blk_rq_map_user_iov to support the bounce buffer.

Signed-off-by: FUJITA Tomonori 
Cc: Mike Christie 
Signed-off-by: Jens Axboe

block: add dma alignment and padding support to blk_rq_map_kern

2008-04-29T07:50:34+00:00

This patch adds bio_copy_kern similar to
bio_copy_user. blk_rq_map_kern uses bio_copy_kern instead of
bio_map_kern if necessary.

bio_copy_kern uses temporary pages and the bi_end_io callback frees
these pages. bio_copy_kern saves the original kernel buffer at
bio->bi_private it doesn't use something like struct bio_map_data to
store the information about the caller.

Signed-off-by: FUJITA Tomonori 
Cc: Tejun Heo 
Signed-off-by: Jens Axboe

block: move the padding adjustment to blk_rq_map_sg

2008-04-21T07:50:08+00:00

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 e97a294ef6938512b655b1abf17656cf2b26f709 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: FUJITA Tomonori 
Cc: Tejun Heo 
Cc: Mike Christie 
Cc: James Bottomley 
Signed-off-by: Jens Axboe

block: add bio_copy_user_iov support to blk_rq_map_user_iov

2008-04-21T07:50:08+00:00

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: FUJITA Tomonori 
Cc: Tejun Heo 
Cc: Mike Christie 
Cc: James Bottomley 
Signed-off-by: Jens Axboe

block: fix shadowed variable warning in blk-map.c

2008-03-04T10:31:22+00:00

Introduced between 2.6.25-rc2 and -rc3
block/blk-map.c:154:14: warning: symbol 'bio' shadows an earlier one
block/blk-map.c:110:13: originally declared here

Signed-off-by: Harvey Harrison 
Signed-off-by: Jens Axboe

unexport blk_rq_map_user_iov

2008-03-04T10:28:34+00:00

This patch removes the unused export of blk_rq_map_user_iov.

Signed-off-by: Adrian Bunk 
Signed-off-by: Jens Axboe

block: separate out padding from alignment

2008-03-04T10:18:17+00:00

Block layer alignment was used for two different purposes - memory
alignment and padding.  This causes problems in lower layers because
drivers which only require memory alignment ends up with adjusted
rq->data_len.  Separate out padding such that padding occurs iff
driver explicitly requests it.

Tomo: restorethe code to update bio in blk_rq_map_user
      introduced by the commit 40b01b9bbdf51ae543a04744283bf2d56c4a6afa
      according to padding alignment.

Signed-off-by: Tejun Heo 
Signed-off-by: FUJITA Tomonori 
Signed-off-by: Jens Axboe

block: restore the meaning of rq->data_len to the true data length

2008-03-04T10:17:11+00:00

The meaning of rq->data_len was changed to the length of an allocated
buffer from the true data length. It breaks SG_IO friends and
bsg. This patch restores the meaning of rq->data_len to the true data
length and adds rq->extra_len to store an extended length (due to
drain buffer and padding).

This patch also removes the code to update bio in blk_rq_map_user
introduced by the commit 40b01b9bbdf51ae543a04744283bf2d56c4a6afa.
The commit adjusts bio according to memory alignment
(queue_dma_alignment). However, memory alignment is NOT padding
alignment. This adjustment also breaks SG_IO friends and bsg. Padding
alignment needs to be fixed in a proper way (by a separate patch).

Signed-off-by: FUJITA Tomonori 
Signed-off-by: Jens Axboe