Re: 2.6.34-rc1 eat my photo SD card :-(

[Roland Dreier <roland@digitalvampire.org>]

 > Well, I spent the last 36 hours (more or less) trying to bisect the SD
 > problem. The method I used was to insert the card, umount it, and make 8 dd
 > in a row; the kernel is "bad" if they differs, "good" if they are the same. 
 > 
 > I could not finish the bisect. The last pair good/bad were:
 > 
 > bad:   [7aeacf982203fb4dea2f3434eefdc268cfd5d6d9] 
 >        [BLOCK] blk_rq_map_sg: force clear termination bit
 > good:  [e38f981758118d829cd40cfe9c09e3fa81e422aa] 
 >        exportfs: update documentation

Thanks, that helps.  I read over the mmc changes in between those two
commits, and I think I found the problem... could you please try the
patch below (on top of the latest kernel) and report back how it
works?  Unfortunately I am traveling and I don't have an SD card with
me to test on my laptop...

Pierre, assuming Romano tests this patch successfully, please apply!

Thanks,
  Roland

<-- patch below -->

mmc: Fix sg helper copy-and-paste error

Commit 45711f1a ("[SG] Update drivers to use sg helpers") had the
following bogus change in drivers/mmc/card/queue.c:

    > -			src_buf = page_address(src->page) + src->offset;
    > +			src_buf = sg_virt(dst);

(Notice that "src" is converted to "dst").  Turn this "dst" back into
the intended "src".

Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Roland Dreier <roland@digitalvampire.org>
---
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 9203a0b..1b9c9b6 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -310,7 +310,7 @@ static void copy_sg(struct scatterlist *dst, unsigned int dst_len,
 		}
 
 		if (src_size == 0) {
-			src_buf = sg_virt(dst);
+			src_buf = sg_virt(src);
 			src_size = src->length;
 		}