| Message ID | 20190408073308.3082-1-hans@owltronix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | lightnvm: pblk: fix crash in pblk_end_partial_read due to multipage bvecs | expand |
> On 8 Apr 2019, at 09.33, hans@owltronix.com wrote: > > From: Hans Holmberg <hans.holmberg@cnexlabs.com> > > Ever since '07173c3ec276 ("block: enable multipage bvecs")' we > need to handle bios with multipage bvecs in pblk. > > Currently, a multipage bvec results in a crash[1]. > Fix this by using bvec iterators in stead of direct bvec indexing. > > Also add a dcache flush, for the same reasons as in: > '6e6e811d747b ("block: Add missing flush_dcache_page() call")' > > [1] https://github.com/OpenChannelSSD/linux/issues/61 > > Reported-by: Klaus Jensen <klaus.jensen@cnexlabs.com> > Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> > --- > > It ain't pretty, but let's fix the breakage while waiting for Igor's > partial read cleanup to be ready. > I would prefer to have the real fix, but it is good to have this fixed for 5.2. Can we agree on a revert if Igor sends the patch within the 5.2 window? Javier
On Wed, Apr 10, 2019 at 2:22 PM Javier González <javier@javigon.com> wrote: > > > On 8 Apr 2019, at 09.33, hans@owltronix.com wrote: > > > > From: Hans Holmberg <hans.holmberg@cnexlabs.com> > > > > Ever since '07173c3ec276 ("block: enable multipage bvecs")' we > > need to handle bios with multipage bvecs in pblk. > > > > Currently, a multipage bvec results in a crash[1]. > > Fix this by using bvec iterators in stead of direct bvec indexing. > > > > Also add a dcache flush, for the same reasons as in: > > '6e6e811d747b ("block: Add missing flush_dcache_page() call")' > > > > [1] https://github.com/OpenChannelSSD/linux/issues/61 > > > > Reported-by: Klaus Jensen <klaus.jensen@cnexlabs.com> > > Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> > > --- > > > > It ain't pretty, but let's fix the breakage while waiting for Igor's > > partial read cleanup to be ready. > > > > I would prefer to have the real fix, but it is good to have this fixed for > 5.2. Can we agree on a revert if Igor sends the patch within the 5.2 > window? yeah! please chuck this patch out of the window when we have a nicer fix ready. Thanks, Hans
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c index f08f7d9bd3be..27f8a76d8bd8 100644 --- a/drivers/lightnvm/pblk-read.c +++ b/drivers/lightnvm/pblk-read.c @@ -230,14 +230,14 @@ static void pblk_end_partial_read(struct nvm_rq *rqd) struct pblk_sec_meta *meta; struct bio *new_bio = rqd->bio; struct bio *bio = pr_ctx->orig_bio; - struct bio_vec src_bv, dst_bv; void *meta_list = rqd->meta_list; - int bio_init_idx = pr_ctx->bio_init_idx; unsigned long *read_bitmap = pr_ctx->bitmap; + struct bvec_iter orig_iter = BVEC_ITER_ALL_INIT; + struct bvec_iter new_iter = BVEC_ITER_ALL_INIT; int nr_secs = pr_ctx->orig_nr_secs; int nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs); void *src_p, *dst_p; - int hole, i; + int bit, i; if (unlikely(nr_holes == 1)) { struct ppa_addr ppa; @@ -256,33 +256,39 @@ static void pblk_end_partial_read(struct nvm_rq *rqd) /* Fill the holes in the original bio */ i = 0; - hole = find_first_zero_bit(read_bitmap, nr_secs); - do { - struct pblk_line *line; + for (bit = 0; bit < nr_secs; bit++) { + if (!test_bit(bit, read_bitmap)) { + struct bio_vec dst_bv, src_bv; + struct pblk_line *line; - line = pblk_ppa_to_line(pblk, rqd->ppa_list[i]); - kref_put(&line->ref, pblk_line_put); + line = pblk_ppa_to_line(pblk, rqd->ppa_list[i]); + kref_put(&line->ref, pblk_line_put); - meta = pblk_get_meta(pblk, meta_list, hole); - meta->lba = cpu_to_le64(pr_ctx->lba_list_media[i]); + meta = pblk_get_meta(pblk, meta_list, bit); + meta->lba = cpu_to_le64(pr_ctx->lba_list_media[i]); - src_bv = new_bio->bi_io_vec[i++]; - dst_bv = bio->bi_io_vec[bio_init_idx + hole]; + dst_bv = bio_iter_iovec(bio, orig_iter); + src_bv = bio_iter_iovec(new_bio, new_iter); - src_p = kmap_atomic(src_bv.bv_page); - dst_p = kmap_atomic(dst_bv.bv_page); + src_p = kmap_atomic(src_bv.bv_page); + dst_p = kmap_atomic(dst_bv.bv_page); - memcpy(dst_p + dst_bv.bv_offset, - src_p + src_bv.bv_offset, - PBLK_EXPOSED_PAGE_SIZE); + memcpy(dst_p + dst_bv.bv_offset, + src_p + src_bv.bv_offset, + PBLK_EXPOSED_PAGE_SIZE); - kunmap_atomic(src_p); - kunmap_atomic(dst_p); + kunmap_atomic(src_p); + kunmap_atomic(dst_p); - mempool_free(src_bv.bv_page, &pblk->page_bio_pool); + flush_dcache_page(dst_bv.bv_page); + mempool_free(src_bv.bv_page, &pblk->page_bio_pool); - hole = find_next_zero_bit(read_bitmap, nr_secs, hole + 1); - } while (hole < nr_secs); + bio_advance_iter(new_bio, &new_iter, + PBLK_EXPOSED_PAGE_SIZE); + i++; + } + bio_advance_iter(bio, &orig_iter, PBLK_EXPOSED_PAGE_SIZE); + } bio_put(new_bio); kfree(pr_ctx);