Am 14.01.2015 um 00:30 schrieb Jens Axboe: >> If I understand you correctly it can happen that blk_rq_bytes() returns >> more bytes than blk_rq_map_sg() allocated, right? > > No, the number of bytes will be the same, no magic is involved :-)
Good to know. :) > But lets say the initial request has 4 bios, with each 2 pages, for a > total of 8 segments. Lets further assume that the pages in each bio are > contiguous, so that blk_rq_map_sg() will map this to 4 sg elements, each > 2xpages long. > > Now, this may already be handled just fine, and you don't need to > update/store the actual sg count. I just looked at the source, and I'm > assuming it'll do the right thing (ubi_read_sg() will bump the active sg > element, when that size has been consumed), but I don't have > ubi_read_sg() in my tree to verify. Currently the sg count is hard coded to UBI_MAX_SG_COUNT. I'm sorry, I forgot to CC you and hch to this patch: https://lkml.org/lkml/2015/1/10/204 Thanks, //richard -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/