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authorJavier González <jg@lightnvm.io>2017-07-28 15:13:16 +0200
committerJens Axboe <axboe@kernel.dk>2017-07-28 08:06:00 -0600
commit75cb8e939cf30ebdfffd9b28566d8aead95138a8 (patch)
tree867ba4c5211487b1aa5907302054efc7bead8ec4
parent5a60f4b6da95b91d17425923fa61e1844af0aff0 (diff)
lightnvm: pblk: advance bio according to lba index
When a lba either hits the cache or corresponds to an empty entry in the L2P table, we need to advance the bio according to the position in which the lba is located. Otherwise, we will copy data in the wrong page, thus causing data corruption for the application. In case of a cache hit, we assumed that bio->bi_iter.bi_idx would contain the correct index, but this is no necessarily true. Instead, use the local bio advance counter and iterator. This guarantees that lbas hitting the cache are copied into the right bv_page. In case of an empty L2P entry, we omitted to advance the bio. In the cases when the same I/O also contains a cache hit, data corresponding to this lba will be copied to the wrong bv_page. Fix this by advancing the bio as we do in the case of a cache hit. Fixes: a4bd217b4326 lightnvm: physical block device (pblk) target Signed-off-by: Javier González <javier@javigon.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--drivers/lightnvm/pblk-rb.c4
-rw-r--r--drivers/lightnvm/pblk-read.c23
-rw-r--r--drivers/lightnvm/pblk.h2
3 files changed, 19 insertions, 10 deletions
diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c
index 5ecc154f6831..9bc32578a766 100644
--- a/drivers/lightnvm/pblk-rb.c
+++ b/drivers/lightnvm/pblk-rb.c
@@ -657,7 +657,7 @@ try:
* be directed to disk.
*/
int pblk_rb_copy_to_bio(struct pblk_rb *rb, struct bio *bio, sector_t lba,
- struct ppa_addr ppa, int bio_iter)
+ struct ppa_addr ppa, int bio_iter, bool advanced_bio)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
struct pblk_rb_entry *entry;
@@ -694,7 +694,7 @@ int pblk_rb_copy_to_bio(struct pblk_rb *rb, struct bio *bio, sector_t lba,
* filled with data from the cache). If part of the data resides on the
* media, we will read later on
*/
- if (unlikely(!bio->bi_iter.bi_idx))
+ if (unlikely(!advanced_bio))
bio_advance(bio, bio_iter * PBLK_EXPOSED_PAGE_SIZE);
data = bio_data(bio);
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index 4e5c48f3de62..d682e89e6493 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -26,7 +26,7 @@
*/
static int pblk_read_from_cache(struct pblk *pblk, struct bio *bio,
sector_t lba, struct ppa_addr ppa,
- int bio_iter)
+ int bio_iter, bool advanced_bio)
{
#ifdef CONFIG_NVM_DEBUG
/* Callers must ensure that the ppa points to a cache address */
@@ -34,7 +34,8 @@ static int pblk_read_from_cache(struct pblk *pblk, struct bio *bio,
BUG_ON(!pblk_addr_in_cache(ppa));
#endif
- return pblk_rb_copy_to_bio(&pblk->rwb, bio, lba, ppa, bio_iter);
+ return pblk_rb_copy_to_bio(&pblk->rwb, bio, lba, ppa,
+ bio_iter, advanced_bio);
}
static void pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
@@ -44,7 +45,7 @@ static void pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
struct ppa_addr ppas[PBLK_MAX_REQ_ADDRS];
sector_t blba = pblk_get_lba(bio);
int nr_secs = rqd->nr_ppas;
- int advanced_bio = 0;
+ bool advanced_bio = false;
int i, j = 0;
/* logic error: lba out-of-bounds. Ignore read request */
@@ -62,19 +63,26 @@ static void pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
retry:
if (pblk_ppa_empty(p)) {
WARN_ON(test_and_set_bit(i, read_bitmap));
- continue;
+
+ if (unlikely(!advanced_bio)) {
+ bio_advance(bio, (i) * PBLK_EXPOSED_PAGE_SIZE);
+ advanced_bio = true;
+ }
+
+ goto next;
}
/* Try to read from write buffer. The address is later checked
* on the write buffer to prevent retrieving overwritten data.
*/
if (pblk_addr_in_cache(p)) {
- if (!pblk_read_from_cache(pblk, bio, lba, p, i)) {
+ if (!pblk_read_from_cache(pblk, bio, lba, p, i,
+ advanced_bio)) {
pblk_lookup_l2p_seq(pblk, &p, lba, 1);
goto retry;
}
WARN_ON(test_and_set_bit(i, read_bitmap));
- advanced_bio = 1;
+ advanced_bio = true;
#ifdef CONFIG_NVM_DEBUG
atomic_long_inc(&pblk->cache_reads);
#endif
@@ -83,6 +91,7 @@ retry:
rqd->ppa_list[j++] = p;
}
+next:
if (advanced_bio)
bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
}
@@ -282,7 +291,7 @@ retry:
* write buffer to prevent retrieving overwritten data.
*/
if (pblk_addr_in_cache(ppa)) {
- if (!pblk_read_from_cache(pblk, bio, lba, ppa, 0)) {
+ if (!pblk_read_from_cache(pblk, bio, lba, ppa, 0, 1)) {
pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
goto retry;
}
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 0c5692cc2f60..67e623bd5c2d 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -670,7 +670,7 @@ unsigned int pblk_rb_read_to_bio_list(struct pblk_rb *rb, struct bio *bio,
struct list_head *list,
unsigned int max);
int pblk_rb_copy_to_bio(struct pblk_rb *rb, struct bio *bio, sector_t lba,
- struct ppa_addr ppa, int bio_iter);
+ struct ppa_addr ppa, int bio_iter, bool advanced_bio);
unsigned int pblk_rb_read_commit(struct pblk_rb *rb, unsigned int entries);
unsigned int pblk_rb_sync_init(struct pblk_rb *rb, unsigned long *flags);