Messages in this thread | | | Date | Wed, 13 Sep 2006 11:30:09 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH 1/2] block: Modify blk_rq_map_user to support large requests |
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On Sat, Sep 09 2006, Mike Christie wrote: > Currently, there is some duplication between bsg, scsi_ioctl.c > and scsi_lib.c/sg/st in its mapping code. This patch modifies > the block layer blk_rq_map_user code to support large requests so > that the scsi and block drivers can use this common code. The > changes also make it so the callers do not have to account for > the bio to be unmapped and bounce buffers. > > The next patch then coverts bsg.c, scsi_ioctl.c and cdrom.c > to use the updated functions. For scsi_ioctl.c and cdrom.c > the only thing that changes is that they no longer have > to do the bounce buffer management and pass in the len for > the unmapping. The bsg change is a little larger since that > code was duplicating a lot of code that is now common > in the block layer. The bsg conversions als should fix > a memory leak caused when unmapping a hdr with iovec_count=0. > > Patch was made over Jens's block tree and the bsg branch
Generally it looks good - two comments:
- I see some advantages to having biohead_orig to avoid keeping track of it and passing it around, but there's also good reasons for _not_ adding more stuff to struct request. Any particular reason you chose to do that?
- blk_get_bounced_bio() looks redundant. BIO_BOUNCED should only be set on a bounced bio, and ->bi_private should always hold that bounced bio.
-- Jens Axboe
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