Re: [PATCH] lightnvm: move bad block and chunk state logic to core

From: Matias BjÃrling
Date: Tue Aug 21 2018 - 07:50:12 EST


On 08/20/2018 02:13 PM, Javier Gonzalez wrote:
On 17 Aug 2018, at 13.14, Matias BjÃrling <mb@xxxxxxxxxxx> wrote:

pblk implements two data paths for recovery line state. One for 1.2
and another for 2.0, instead of having pblk implement these, combine
them in the core to reduce complexity and make available to other
targets.

The new interface will adhere to the 2.0 chunk definition,
including managing open chunks with an active write pointer. To provide
this interface, a 1.2 device recovers the state of the chunks by
manually detecting if a chunk is either free/open/close/offline, and if
open, scanning the flash pages sequentially to find the next writeable
page. This process takes on average ~10 seconds on a device with 64 dies,
1024 blocks and 60us read access time. The process can be parallelized
but is left out for maintenance simplicity, as the 1.2 specification is
deprecated. For 2.0 devices, the logic is maintained internally in the
drive and retrieved through the 2.0 interface.

A couple of things from closer review.


Signed-off-by: Matias BjÃrling <mb@xxxxxxxxxxx>
---
drivers/lightnvm/core.c | 310 +++++++++++++++++++++++++++++++++++--------
drivers/lightnvm/pblk-core.c | 6 +-
drivers/lightnvm/pblk-init.c | 116 +---------------
drivers/lightnvm/pblk.h | 2 +-
drivers/nvme/host/lightnvm.c | 4 +-
include/linux/lightnvm.h | 15 +--
6 files changed, 266 insertions(+), 187 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 964352720a03..003fc073f496 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -717,46 +717,6 @@ static void nvm_free_rqd_ppalist(struct nvm_tgt_dev *tgt_dev,
nvm_dev_dma_free(tgt_dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
}

-int nvm_get_chunk_meta(struct nvm_tgt_dev *tgt_dev, struct nvm_chk_meta *meta,
- struct ppa_addr ppa, int nchks)
-{
- struct nvm_dev *dev = tgt_dev->parent;
-
- nvm_ppa_tgt_to_dev(tgt_dev, &ppa, 1);
-
- return dev->ops->get_chk_meta(tgt_dev->parent, meta,
- (sector_t)ppa.ppa, nchks);
-}
-EXPORT_SYMBOL(nvm_get_chunk_meta);
-
-int nvm_set_tgt_bb_tbl(struct nvm_tgt_dev *tgt_dev, struct ppa_addr *ppas,
- int nr_ppas, int type)
-{
- struct nvm_dev *dev = tgt_dev->parent;
- struct nvm_rq rqd;
- int ret;
-
- if (nr_ppas > NVM_MAX_VLBA) {
- pr_err("nvm: unable to update all blocks atomically\n");
- return -EINVAL;
- }
-
- memset(&rqd, 0, sizeof(struct nvm_rq));
-
- nvm_set_rqd_ppalist(tgt_dev, &rqd, ppas, nr_ppas);
- nvm_rq_tgt_to_dev(tgt_dev, &rqd);
-
- ret = dev->ops->set_bb_tbl(dev, &rqd.ppa_addr, rqd.nr_ppas, type);
- nvm_free_rqd_ppalist(tgt_dev, &rqd);
- if (ret) {
- pr_err("nvm: failed bb mark\n");
- return -EINVAL;
- }
-
- return 0;
-}
-EXPORT_SYMBOL(nvm_set_tgt_bb_tbl);
-
static int nvm_set_flags(struct nvm_geo *geo, struct nvm_rq *rqd)
{
int flags = 0;
@@ -830,27 +790,159 @@ void nvm_end_io(struct nvm_rq *rqd)
}
EXPORT_SYMBOL(nvm_end_io);

+static int nvm_submit_io_sync_raw(struct nvm_dev *dev, struct nvm_rq *rqd)
+{
+ if (!dev->ops->submit_io_sync)
+ return -ENODEV;
+
+ rqd->flags = nvm_set_flags(&dev->geo, rqd);
+
+ return dev->ops->submit_io_sync(dev, rqd);
+}
+
+static int nvm_bb_chunk_sense(struct nvm_dev *dev, struct ppa_addr ppa)
+{
+ struct nvm_rq rqd = { NULL };
+ struct bio bio;
+ struct bio_vec bio_vec;
+ struct page *page;
+ int ret;
+
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ bio_init(&bio, &bio_vec, 1);
+ bio_add_page(&bio, page, PAGE_SIZE, 0);
+ bio_set_op_attrs(&bio, REQ_OP_READ, 0);
+
+ rqd.bio = &bio;
+ rqd.opcode = NVM_OP_PREAD;
+ rqd.is_seq = 1;
+ rqd.nr_ppas = 1;
+ rqd.ppa_addr = generic_to_dev_addr(dev, ppa);
+
+ ret = nvm_submit_io_sync_raw(dev, &rqd);
+ if (ret)
+ return ret;
+
+ __free_page(page);
+
+ return rqd.error;
+}
+
/*
- * folds a bad block list from its plane representation to its virtual
- * block representation. The fold is done in place and reduced size is
- * returned.
+ * Scans a 1.2 chunk first and last page to determine if its state.
+ * If the chunk is found to be open, also scan it to update the write
+ * pointer.
+ */
+static int nvm_bb_scan_chunk(struct nvm_dev *dev, struct ppa_addr ppa,
+ struct nvm_chk_meta *meta)

Keeping some name consistency would help nvm_bb_chunk_*

[...]

+
+static int nvm_get_bb_meta(struct nvm_dev *dev, sector_t slba,
+ int nchks, struct nvm_chk_meta *meta)
+{
+ struct nvm_geo *geo = &dev->geo;
+ struct ppa_addr ppa;
+ u8 *blks;
+ int ch, lun, nr_blks;
+ int ret;
+
+ ppa.ppa = slba;
+ ppa = dev_to_generic_addr(dev, ppa);
+
+ if (ppa.g.blk != 0)
+ return -EINVAL;
+
+ if ((nchks % geo->num_chk) != 0)
+ return -EINVAL;
+
+ nr_blks = geo->num_chk * geo->pln_mode;
+
+ blks = kmalloc(nr_blks, GFP_KERNEL);
+ if (!blks)
+ return -ENOMEM;
+
+ for (ch = ppa.g.ch; ch < geo->num_ch; ch++) {
+ for (lun = ppa.g.lun; lun < geo->num_lun; lun++) {
+ struct ppa_addr ppa_gen, ppa_dev;
+
+ if (!nchks)
+ goto out;

You should free blks here too.

+
+ ppa_gen.ppa = 0;
+ ppa_gen.a.ch = ch;
+ ppa_gen.a.lun = lun;
+ ppa_dev = generic_to_dev_addr(dev, ppa_gen);
+
+ ret = dev->ops->get_bb_tbl(dev, ppa_dev, blks);
+ if (ret)
+ goto err;
+
+ ret = nvm_bb_to_chunk(dev, ppa_gen, blks, nr_blks,
+ meta);
+ if (ret)
+ goto err;
+
+ meta += geo->num_chk;
+ nchks -= geo->num_chk;
+ }
+ }
+out:
+ return 0;
+err:
+ kfree(blks);
+ return ret;
}
-EXPORT_SYMBOL(nvm_bb_tbl_fold);

-int nvm_get_tgt_bb_tbl(struct nvm_tgt_dev *tgt_dev, struct ppa_addr ppa,
- u8 *blks)
[...]



Thanks, I've merged it into the patch.