lightnvm: pblk: stop writes gracefully when running out of lines

If mapping fails (i.e. when running out of lines), handle the error
and stop writing.

Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
index 6dcbd44..5a3c28c 100644 (file)
--- a/drivers/lightnvm/pblk-map.c
+++ b/drivers/lightnvm/pblk-map.c
@@ -33,6 +33,9 @@ static int pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
        int nr_secs = pblk->min_write_pgs;
        int i;
 
+       if (!line)
+               return -ENOSPC;
+
        if (pblk_line_is_full(line)) {
                struct pblk_line *prev_line = line;
 
@@ -42,8 +45,11 @@ static int pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
                line = pblk_line_replace_data(pblk);
                pblk_line_close_meta(pblk, prev_line);
 
-               if (!line)
-                       return -EINTR;
+               if (!line) {
+                       pblk_pipeline_stop(pblk);
+                       return -ENOSPC;
+               }
+
        }
 
        emeta = line->emeta;
@@ -84,7 +90,7 @@ static int pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
        return 0;
 }
 
-void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
+int pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
                 unsigned long *lun_bitmap, unsigned int valid_secs,
                 unsigned int off)
 {
@@ -93,20 +99,22 @@ void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
        unsigned int map_secs;
        int min = pblk->min_write_pgs;
        int i;
+       int ret;
 
        for (i = off; i < rqd->nr_ppas; i += min) {
                map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
-               if (pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
-                                       lun_bitmap, &meta_list[i], map_secs)) {
-                       bio_put(rqd->bio);
-                       pblk_free_rqd(pblk, rqd, PBLK_WRITE);
-                       pblk_pipeline_stop(pblk);
-               }
+
+               ret = pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
+                                       lun_bitmap, &meta_list[i], map_secs);
+               if (ret)
+                       return ret;
        }
+
+       return 0;
 }
 
 /* only if erase_ppa is set, acquire erase semaphore */
-void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
+int pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
                       unsigned int sentry, unsigned long *lun_bitmap,
                       unsigned int valid_secs, struct ppa_addr *erase_ppa)
 {
@@ -119,15 +127,16 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
        unsigned int map_secs;
        int min = pblk->min_write_pgs;
        int i, erase_lun;
+       int ret;
+
 
        for (i = 0; i < rqd->nr_ppas; i += min) {
                map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
-               if (pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
-                                       lun_bitmap, &meta_list[i], map_secs)) {
-                       bio_put(rqd->bio);
-                       pblk_free_rqd(pblk, rqd, PBLK_WRITE);
-                       pblk_pipeline_stop(pblk);
-               }
+
+               ret = pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
+                                       lun_bitmap, &meta_list[i], map_secs);
+               if (ret)
+                       return ret;
 
                erase_lun = pblk_ppa_to_pos(geo, ppa_list[i]);
 
@@ -163,7 +172,7 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
         */
        e_line = pblk_line_get_erase(pblk);
        if (!e_line)
-               return;
+               return -ENOSPC;
 
        /* Erase blocks that are bad in this line but might not be in next */
        if (unlikely(pblk_ppa_empty(*erase_ppa)) &&
@@ -174,7 +183,7 @@ retry:
                bit = find_next_bit(d_line->blk_bitmap,
                                                lm->blk_per_line, bit + 1);
                if (bit >= lm->blk_per_line)
-                       return;
+                       return 0;
 
                spin_lock(&e_line->lock);
                if (test_bit(bit, e_line->erase_bitmap)) {
@@ -188,4 +197,6 @@ retry:
                *erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
                erase_ppa->a.blk = e_line->id;
        }
+
+       return 0;
 }

diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index 750f04b..2bf78f8 100644 (file)
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -334,12 +334,13 @@ static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
        }
 
        if (likely(!e_line || !atomic_read(&e_line->left_eblks)))
-               pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
+               ret = pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
+                                                       valid, 0);
        else
-               pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
+               ret = pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
                                                        valid, erase_ppa);
 
-       return 0;
+       return ret;
 }
 
 static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
@@ -563,7 +564,7 @@ static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
                                                        c_ctx->nr_padded);
 }
 
-static int pblk_submit_write(struct pblk *pblk)
+static int pblk_submit_write(struct pblk *pblk, int *secs_left)
 {
        struct bio *bio;
        struct nvm_rq *rqd;
@@ -572,6 +573,8 @@ static int pblk_submit_write(struct pblk *pblk)
        unsigned long pos;
        unsigned int resubmit;
 
+       *secs_left = 0;
+
        spin_lock(&pblk->resubmit_lock);
        resubmit = !list_empty(&pblk->resubmit_list);
        spin_unlock(&pblk->resubmit_lock);
@@ -601,17 +604,17 @@ static int pblk_submit_write(struct pblk *pblk)
                 */
                secs_avail = pblk_rb_read_count(&pblk->rwb);
                if (!secs_avail)
-                       return 1;
+                       return 0;
 
                secs_to_flush = pblk_rb_flush_point_count(&pblk->rwb);
                if (!secs_to_flush && secs_avail < pblk->min_write_pgs)
-                       return 1;
+                       return 0;
 
                secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail,
                                        secs_to_flush);
                if (secs_to_sync > pblk->max_write_pgs) {
                        pblk_err(pblk, "bad buffer sync calculation\n");
-                       return 1;
+                       return 0;
                }
 
                secs_to_com = (secs_to_sync > secs_avail) ?
@@ -640,6 +643,7 @@ static int pblk_submit_write(struct pblk *pblk)
        atomic_long_add(secs_to_sync, &pblk->sub_writes);
 #endif
 
+       *secs_left = 1;
        return 0;
 
 fail_free_bio:
@@ -648,16 +652,22 @@ fail_put_bio:
        bio_put(bio);
        pblk_free_rqd(pblk, rqd, PBLK_WRITE);
 
-       return 1;
+       return -EINTR;
 }
 
 int pblk_write_ts(void *data)
 {
        struct pblk *pblk = data;
+       int secs_left;
+       int write_failure = 0;
 
        while (!kthread_should_stop()) {
-               if (!pblk_submit_write(pblk))
-                       continue;
+               if (!write_failure) {
+                       write_failure = pblk_submit_write(pblk, &secs_left);
+
+                       if (secs_left)
+                               continue;
+               }
                set_current_state(TASK_INTERRUPTIBLE);
                io_schedule();
        }

diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 02bb2e9..f415aae 100644 (file)
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -871,10 +871,10 @@ int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq);
 /*
  * pblk map
  */
-void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
+int pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
                       unsigned int sentry, unsigned long *lun_bitmap,
                       unsigned int valid_secs, struct ppa_addr *erase_ppa);
-void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
+int pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
                 unsigned long *lun_bitmap, unsigned int valid_secs,
                 unsigned int off);