lightnvm: pblk: schedule if data is not ready

When user threads place data into the write buffer, they reserve space
and do the memory copy out of the lock. As a consequence, when the write
thread starts persisting data, there is a chance that it is not copied
yet. In this case, avoid polling, and schedule before retrying.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c
index 665a4ccfe7f5d7ab57ff56303fcf407de3b7a4cc..2dda874af8909383f3861af830d7f0194c5a09a0 100644 (file)
--- a/drivers/lightnvm/pblk-rb.c
+++ b/drivers/lightnvm/pblk-rb.c
@@ -578,8 +578,10 @@ unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
                 */
 try:
                flags = READ_ONCE(entry->w_ctx.flags);
-               if (!(flags & PBLK_WRITTEN_DATA))
+               if (!(flags & PBLK_WRITTEN_DATA)) {
+                       io_schedule();
                        goto try;
+               }
 
                page = virt_to_page(entry->data);
                if (!page) {