Messages in this thread | | | Date | Fri, 17 Apr 2009 17:23:42 -0400 | From | Mark Lord <> | Subject | Re: [PATCH 1/5] Block: Discard may need to allocate pages |
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Matthew Wilcox wrote: > From: Matthew Wilcox <matthew@wil.cx> > > SCSI and ATA both need to send data to the device. In order to do this, > the BIO must be allocated with room for a page to be added, and the bio > needs to be passed to the discard prep function. We also need to free > the page attached to the BIO before we free it. > > init_request_from_bio() is not currently called from a context which > forbids sleeping, and to make sure it stays that way (so we don't have > to use GFP_ATOMIC), add a might_sleep() to it. > > Signed-off-by: Matthew Wilcox <willy@linux.intel.com> ... > @@ -1118,7 +1120,7 @@ void init_request_from_bio(struct request *req, struct bio *bio) > req->cmd_flags |= REQ_DISCARD; > if (bio_barrier(bio)) > req->cmd_flags |= REQ_SOFTBARRIER; > - req->q->prepare_discard_fn(req->q, req); > + req->q->prepare_discard_fn(req->q, req, bio); > } else if (unlikely(bio_barrier(bio))) > req->cmd_flags |= (REQ_HARDBARRIER | REQ_NOMERGE); > ..
Matthew, note that prepare_discardfn() may fail, and return an error result. The above code does not check for this or handle it very well.
Cheers
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