lightnvm: refactor end_io functions for sync

To implement sync I/O support within the LightNVM core, the end_io
functions are refactored to take an end_io function pointer instead of
testing for initialized media manager, followed by calling its end_io
function.

Sync I/O can then be implemented using a callback that signal I/O
completion. This is similar to the logic found in blk_to_execute_io().
By implementing it this way, the underlying device I/Os submission logic
is abstracted away from core, targets, and media managers.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 081b0f59b773..fa1a052c4737 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -27,6 +27,7 @@
 #include <linux/module.h>
 #include <linux/miscdevice.h>
 #include <linux/lightnvm.h>
+#include <linux/sched/sysctl.h>
 #include <uapi/linux/lightnvm.h>
 
 static LIST_HEAD(nvm_targets);
@@ -288,6 +289,21 @@ int nvm_erase_ppa(struct nvm_dev *dev, struct ppa_addr ppa)
 }
 EXPORT_SYMBOL(nvm_erase_ppa);
 
+void nvm_end_io(struct nvm_rq *rqd, int error)
+{
+        rqd->end_io(rqd, error);
+}
+EXPORT_SYMBOL(nvm_end_io);
+
+static void nvm_end_io_sync(struct nvm_rq *rqd, int errors)
+{
+        struct completion *waiting = rqd->wait;
+
+        rqd->wait = NULL;
+
+        complete(waiting);
+}
+
 static int nvm_core_init(struct nvm_dev *dev)
 {
         struct nvm_id *id = &dev->identity;