Commit 4fc981ef authored May 19, 2009 by Tejun Heo Committed by Jens Axboe May 19, 2009

bio: always copy back data for copied kernel requests



When a read bio_copy_kern() request fails, the content of the bounce
buffer is not copied back.  However, as request failure doesn't
necessarily mean complete failure, the buffer state can be useful.
This behavior is also inconsistent with the user map counterpart and
causes the subtle difference between bounced and unbounced IO causes
confusion.

This patch makes bio_copy_kern_endio() ignore @err and always copy
back data on request completion.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

parent 5f49f631

fs/bio.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1198,7 +1198,7 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
		char *addr = page_address(bvec->bv_page);
		int len = bmd->iovecs[i].bv_len;

		if (read && !err)
		if (read)
		memcpy(p, addr, len);

		__free_page(bvec->bv_page);

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