[PATCH 08/15] libnvdimm, btt: add support for blk integrity

Dan Williams
2015-06-18T00:00:40Z

From: Vishal Verma <vishal.l.verma@linux.intel.com>

Support multiple block sizes (sector + metadata) using the blk integrity
framework. This registers a new integrity template that defines the
protection information tuple size based on the configured metadata size,
and simply acts as a passthrough for protection information generated by
another layer. The metadata is written to the storage as-is, and read back
with each sector.

Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/nvdimm/btt.c | 126 +++++++++++++++++++++++++++++++++++++++------
drivers/nvdimm/btt.h | 2 -
drivers/nvdimm/btt_devs.c | 3 +
drivers/nvdimm/core.c | 37 +++++++++++++
drivers/nvdimm/nd.h | 1
5 files changed, 151 insertions(+), 18 deletions(-)

diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 58becbd69ae1..c337b7abfb43 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -837,6 +837,11 @@ static int btt_meta_init(struct btt *btt)
return ret;
}

+static u32 btt_meta_size(struct btt *btt)
+{
+ return btt->lbasize - btt->sector_size;
+}
+
/*
* This function calculates the arena in which the given LBA lies
* by doing a linear walk. This is acceptable since we expect only
@@ -921,8 +926,63 @@ static void zero_fill_data(struct page *page, unsigned int off, u32 len)
kunmap_atomic(mem);
}

-static int btt_read_pg(struct btt *btt, struct page *page, unsigned int off,
- sector_t sector, unsigned int len)
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
+ struct arena_info *arena, u32 postmap, int rw)
+{
+ unsigned int len = btt_meta_size(btt);
+ u64 meta_nsoff;
+ int ret = 0;
+
+ if (bip == NULL)
+ return 0;
+
+ meta_nsoff = to_namespace_offset(arena, postmap) + btt->sector_size;
+
+ while (len) {
+ unsigned int cur_len;
+ struct bio_vec bv;
+ void *mem;
+
+ bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
+ /*
+ * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
+ * .bv_offset already adjusted for iter->bi_bvec_done, and we
+ * can use those directly
+ */
+
+ cur_len = min(len, bv.bv_len);
+ mem = kmap_atomic(bv.bv_page);
+ if (rw)
+ ret = arena_write_bytes(arena, meta_nsoff,
+ mem + bv.bv_offset, cur_len);
+ else
+ ret = arena_read_bytes(arena, meta_nsoff,
+ mem + bv.bv_offset, cur_len);
+
+ kunmap_atomic(mem);
+ if (ret)
+ return ret;
+
+ len -= cur_len;
+ meta_nsoff += cur_len;
+ bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
+ }
+
+ return ret;
+}
+
+#else /* CONFIG_BLK_DEV_INTEGRITY */
+static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
+ struct arena_info *arena, u32 postmap, int rw)
+{
+ return 0;
+}
+#endif
+
+static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip,
+ struct page *page, unsigned int off, sector_t sector,
+ unsigned int len)
{
int ret = 0;
int t_flag, e_flag;
@@ -984,6 +1044,12 @@ static int btt_read_pg(struct btt *btt, struct page *page, unsigned int off,
if (ret)
goto out_rtt;

+ if (bip) {
+ ret = btt_rw_integrity(btt, bip, arena, postmap, READ);
+ if (ret)
+ goto out_rtt;
+ }
+
arena->rtt[lane] = RTT_INVALID;
nd_region_release_lane(btt->nd_region, lane);

@@ -1001,8 +1067,9 @@ static int btt_read_pg(struct btt *btt, struct page *page, unsigned int off,
return ret;
}

-static int btt_write_pg(struct btt *btt, sector_t sector, struct page *page,
- unsigned int off, unsigned int len)
+static int btt_write_pg(struct btt *btt, struct bio_integrity_payload *bip,
+ sector_t sector, struct page *page, unsigned int off,
+ unsigned int len)
{
int ret = 0;
struct arena_info *arena = NULL;
@@ -1036,12 +1103,19 @@ static int btt_write_pg(struct btt *btt, sector_t sector, struct page *page,
if (new_postmap >= arena->internal_nlba) {
ret = -EIO;
goto out_lane;
- } else
- ret = btt_data_write(arena, new_postmap, page,
- off, cur_len);
+ }
+
+ ret = btt_data_write(arena, new_postmap, page, off, cur_len);
if (ret)
goto out_lane;

+ if (bip) {
+ ret = btt_rw_integrity(btt, bip, arena, new_postmap,
+ WRITE);
+ if (ret)
+ goto out_lane;
+ }
+
lock_map(arena, premap);
ret = btt_map_read(arena, premap, &old_postmap, NULL, NULL);
if (ret)
@@ -1081,18 +1155,18 @@ static int btt_write_pg(struct btt *btt, sector_t sector, struct page *page,
return ret;
}

-static int btt_do_bvec(struct btt *btt, struct page *page,
- unsigned int len, unsigned int off, int rw,
- sector_t sector)
+static int btt_do_bvec(struct btt *btt, struct bio_integrity_payload *bip,
+ struct page *page, unsigned int len, unsigned int off,
+ int rw, sector_t sector)
{
int ret;

if (rw == READ) {
- ret = btt_read_pg(btt, page, off, sector, len);
+ ret = btt_read_pg(btt, bip, page, off, sector, len);
flush_dcache_page(page);
} else {
flush_dcache_page(page);
- ret = btt_write_pg(btt, sector, page, off, len);
+ ret = btt_write_pg(btt, bip, sector, page, off, len);
}

return ret;
@@ -1100,6 +1174,7 @@ static int btt_do_bvec(struct btt *btt, struct page *page,

static void btt_make_request(struct request_queue *q, struct bio *bio)
{
+ struct bio_integrity_payload *bip = bio_integrity(bio);
struct block_device *bdev = bio->bi_bdev;
struct btt *btt = q->queuedata;
int rw;
@@ -1120,6 +1195,17 @@ static void btt_make_request(struct request_queue *q, struct bio *bio)
if (rw == READA)
rw = READ;

+ /*
+ * bio_integrity_enabled also checks if the bio already has an
+ * integrity payload attached. If it does, we *don't* do a
+ * bio_integrity_prep here - the payload has been generated by
+ * another kernel subsystem, and we just pass it through.
+ */
+ if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
+ err = -EIO;
+ goto out;
+ }
+
bio_for_each_segment(bvec, bio, iter) {
unsigned int len = bvec.bv_len;

@@ -1129,7 +1215,7 @@ static void btt_make_request(struct request_queue *q, struct bio *bio)
BUG_ON(len < btt->sector_size);
BUG_ON(len % btt->sector_size);

- err = btt_do_bvec(btt, bvec.bv_page, len, bvec.bv_offset,
+ err = btt_do_bvec(btt, bip, bvec.bv_page, len, bvec.bv_offset,
rw, sector);
if (err) {
dev_info(&btt->nd_btt->dev,
@@ -1150,7 +1236,7 @@ static int btt_rw_page(struct block_device *bdev, sector_t sector,
{
struct btt *btt = bdev->bd_disk->private_data;

- btt_do_bvec(btt, page, PAGE_CACHE_SIZE, 0, rw, sector);
+ btt_do_bvec(btt, NULL, page, PAGE_CACHE_SIZE, 0, rw, sector);
page_endio(page, rw & WRITE, 0);
return 0;
}
@@ -1204,10 +1290,17 @@ static int btt_blk_init(struct btt *btt)
blk_queue_logical_block_size(btt->btt_queue, btt->sector_size);
btt->btt_queue->queuedata = btt;

- set_capacity(btt->btt_disk,
- btt->nlba * btt->sector_size >> SECTOR_SHIFT);
+ set_capacity(btt->btt_disk, 0);
add_disk(btt->btt_disk);

+ if (btt_meta_size(btt)) {
+ ret = nd_integrity_init(btt->btt_disk, btt_meta_size(btt));
+ if (ret)
+ goto out_free_queue;
+ }
+
+ set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9);
+
return 0;

out_free_queue:
@@ -1217,6 +1310,7 @@ out_free_queue:

static void btt_blk_cleanup(struct btt *btt)
{
+ blk_integrity_unregister(btt->btt_disk);
del_gendisk(btt->btt_disk);
put_disk(btt->btt_disk);
blk_cleanup_queue(btt->btt_queue);
diff --git a/drivers/nvdimm/btt.h b/drivers/nvdimm/btt.h
index 8c95a7792c3e..2caa0ef7e67a 100644
--- a/drivers/nvdimm/btt.h
+++ b/drivers/nvdimm/btt.h
@@ -31,7 +31,7 @@
#define ARENA_MAX_SIZE (1ULL << 39) /* 512 GB */
#define RTT_VALID (1UL << 31)
#define RTT_INVALID 0
-#define INT_LBASIZE_ALIGNMENT 256
+#define INT_LBASIZE_ALIGNMENT 64
#define BTT_PG_SIZE 4096
#define BTT_DEFAULT_NFREE ND_MAX_LANES
#define LOG_SEQ_INIT 1
diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index c03c854f892b..02e125b91e77 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -53,7 +53,8 @@ struct nd_btt *to_nd_btt(struct device *dev)
}
EXPORT_SYMBOL(to_nd_btt);

-static const unsigned long btt_lbasize_supported[] = { 512, 4096, 0 };
+static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
+ 4096, 4104, 4160, 4224, 0 };

static ssize_t sector_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index 0fa9b6225450..36f112995c0c 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -13,6 +13,7 @@
#include <linux/libnvdimm.h>
#include <linux/export.h>
#include <linux/module.h>
+#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/ctype.h>
#include <linux/ndctl.h>
@@ -381,6 +382,42 @@ void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
}
EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);

+#ifdef CONFIG_BLK_DEV_INTEGRITY
+static int nd_pi_nop_generate_verify(struct blk_integrity_iter *iter)
+{
+ return 0;
+}
+
+int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
+{
+ struct blk_integrity integrity = {
+ .name = "ND-PI-NOP",
+ .generate_fn = nd_pi_nop_generate_verify,
+ .verify_fn = nd_pi_nop_generate_verify,
+ .tuple_size = meta_size,
+ .tag_size = meta_size,
+ };
+ int ret;
+
+ ret = blk_integrity_register(disk, &integrity);
+ if (ret)
+ return ret;
+
+ blk_queue_max_integrity_segments(disk->queue, 1);
+
+ return 0;
+}
+EXPORT_SYMBOL(nd_integrity_init);
+
+#else /* CONFIG_BLK_DEV_INTEGRITY */
+int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
+{
+ return 0;
+}
+EXPORT_SYMBOL(nd_integrity_init);
+
+#endif
+
static __init int libnvdimm_init(void)
{
int rc;
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 2b7746e798fb..1cea3f191a83 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -128,6 +128,7 @@ enum nd_async_mode {
ND_ASYNC,
};

+int nd_integrity_init(struct gendisk *disk, unsigned long meta_size);
void wait_nvdimm_bus_probe_idle(struct device *dev);
void nd_device_register(struct device *dev);
void nd_device_unregister(struct device *dev, enum nd_async_mode mode);