[GIT PULL 10/20] lightnvm: pass flag on graceful teardown to targets

[Matias Bjørling]

From: Javier González 

If the namespace is unregistered before the LightNVM target is removed
(e.g., on hot unplug) it is too late for the target to store any metadata
on the device - any attempt to write to the device will fail. In this
case, pass on a "gracefull teardown" flag to the target to let it know
when this happens.

In the case of pblk, we pad the open line (close all open chunks) to
improve data retention. In the event of an ungraceful shutdown, avoid
this part and just clean up.

Signed-off-by: Javier González 
Signed-off-by: Matias Bjørling 
---
 drivers/lightnvm/core.c  | 10 +-
 drivers/lightnvm/pblk-core.c | 13 -
 drivers/lightnvm/pblk-gc.c   | 10 ++
 drivers/lightnvm/pblk-init.c | 14 --
 drivers/lightnvm/pblk.h  |  4 +++-
 include/linux/lightnvm.h |  2 +-
 6 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 63171cdce270..60aa7bc5a630 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -431,7 +431,7 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct 
nvm_ioctl_create *create)
return 0;
 err_sysfs:
if (tt->exit)
-   tt->exit(targetdata);
+   tt->exit(targetdata, true);
 err_init:
blk_cleanup_queue(tqueue);
tdisk->queue = NULL;
@@ -446,7 +446,7 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct 
nvm_ioctl_create *create)
return ret;
 }
 
-static void __nvm_remove_target(struct nvm_target *t)
+static void __nvm_remove_target(struct nvm_target *t, bool graceful)
 {
struct nvm_tgt_type *tt = t->type;
struct gendisk *tdisk = t->disk;
@@ -459,7 +459,7 @@ static void __nvm_remove_target(struct nvm_target *t)
tt->sysfs_exit(tdisk);
 
if (tt->exit)
-   tt->exit(tdisk->private_data);
+   tt->exit(tdisk->private_data, graceful);
 
nvm_remove_tgt_dev(t->dev, 1);
put_disk(tdisk);
@@ -489,7 +489,7 @@ static int nvm_remove_tgt(struct nvm_dev *dev, struct 
nvm_ioctl_remove *remove)
mutex_unlock(>mlock);
return 1;
}
-   __nvm_remove_target(t);
+   __nvm_remove_target(t, true);
mutex_unlock(>mlock);
 
return 0;
@@ -963,7 +963,7 @@ void nvm_unregister(struct nvm_dev *dev)
list_for_each_entry_safe(t, tmp, >targets, list) {
if (t->dev->parent != dev)
continue;
-   __nvm_remove_target(t);
+   __nvm_remove_target(t, false);
}
mutex_unlock(>mlock);
 
diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 4b10122aec89..5f1e5b1b3094 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -1461,7 +1461,7 @@ static void pblk_line_close_meta_sync(struct pblk *pblk)
flush_workqueue(pblk->close_wq);
 }
 
-void pblk_pipeline_stop(struct pblk *pblk)
+void __pblk_pipeline_flush(struct pblk *pblk)
 {
struct pblk_line_mgmt *l_mg = >l_mg;
int ret;
@@ -1486,6 +1486,11 @@ void pblk_pipeline_stop(struct pblk *pblk)
 
flush_workqueue(pblk->bb_wq);
pblk_line_close_meta_sync(pblk);
+}
+
+void __pblk_pipeline_stop(struct pblk *pblk)
+{
+   struct pblk_line_mgmt *l_mg = >l_mg;
 
spin_lock(_mg->free_lock);
pblk->state = PBLK_STATE_STOPPED;
@@ -1494,6 +1499,12 @@ void pblk_pipeline_stop(struct pblk *pblk)
spin_unlock(_mg->free_lock);
 }
 
+void pblk_pipeline_stop(struct pblk *pblk)
+{
+   __pblk_pipeline_flush(pblk);
+   __pblk_pipeline_stop(pblk);
+}
+
 struct pblk_line *pblk_line_replace_data(struct pblk *pblk)
 {
struct pblk_line_mgmt *l_mg = >l_mg;
diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index 6851a5c67189..b0cc277bf972 100644
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -649,7 +649,7 @@ int pblk_gc_init(struct pblk *pblk)
return ret;
 }
 
-void pblk_gc_exit(struct pblk *pblk)
+void pblk_gc_exit(struct pblk *pblk, bool graceful)
 {
struct pblk_gc *gc = >gc;
 
@@ -663,10 +663,12 @@ void pblk_gc_exit(struct pblk *pblk)
if (gc->gc_reader_ts)
kthread_stop(gc->gc_reader_ts);
 
-   flush_workqueue(gc->gc_reader_wq);
+   if (graceful) {
+   flush_workqueue(gc->gc_reader_wq);
+   flush_workqueue(gc->gc_line_reader_wq);
+   }
+
destroy_workqueue(gc->gc_reader_wq);
-
-   flush_workqueue(gc->gc_line_reader_wq);
destroy_workqueue(gc->gc_line_reader_wq);
 
if (gc->gc_writer_ts)
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 9e3a43346d4c..bfc488d0dda9 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -1118,23 +1118,25 @@ static void pblk_free(struct pblk *pblk)
kfree(pblk);
 }
 
-static void 

[GIT PULL 10/20] lightnvm: pass flag on graceful teardown to targets

[Matias Bjørling]

From: Javier González 

If the namespace is unregistered before the LightNVM target is removed
(e.g., on hot unplug) it is too late for the target to store any metadata
on the device - any attempt to write to the device will fail. In this
case, pass on a "gracefull teardown" flag to the target to let it know
when this happens.

In the case of pblk, we pad the open line (close all open chunks) to
improve data retention. In the event of an ungraceful shutdown, avoid
this part and just clean up.

Signed-off-by: Javier González 
Signed-off-by: Matias Bjørling 
---
 drivers/lightnvm/core.c  | 10 +-
 drivers/lightnvm/pblk-core.c | 13 -
 drivers/lightnvm/pblk-gc.c   | 10 ++
 drivers/lightnvm/pblk-init.c | 14 --
 drivers/lightnvm/pblk.h  |  4 +++-
 include/linux/lightnvm.h |  2 +-
 6 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 63171cdce270..60aa7bc5a630 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -431,7 +431,7 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct 
nvm_ioctl_create *create)
return 0;
 err_sysfs:
if (tt->exit)
-   tt->exit(targetdata);
+   tt->exit(targetdata, true);
 err_init:
blk_cleanup_queue(tqueue);
tdisk->queue = NULL;
@@ -446,7 +446,7 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct 
nvm_ioctl_create *create)
return ret;
 }
 
-static void __nvm_remove_target(struct nvm_target *t)
+static void __nvm_remove_target(struct nvm_target *t, bool graceful)
 {
struct nvm_tgt_type *tt = t->type;
struct gendisk *tdisk = t->disk;
@@ -459,7 +459,7 @@ static void __nvm_remove_target(struct nvm_target *t)
tt->sysfs_exit(tdisk);
 
if (tt->exit)
-   tt->exit(tdisk->private_data);
+   tt->exit(tdisk->private_data, graceful);
 
nvm_remove_tgt_dev(t->dev, 1);
put_disk(tdisk);
@@ -489,7 +489,7 @@ static int nvm_remove_tgt(struct nvm_dev *dev, struct 
nvm_ioctl_remove *remove)
mutex_unlock(>mlock);
return 1;
}
-   __nvm_remove_target(t);
+   __nvm_remove_target(t, true);
mutex_unlock(>mlock);
 
return 0;
@@ -963,7 +963,7 @@ void nvm_unregister(struct nvm_dev *dev)
list_for_each_entry_safe(t, tmp, >targets, list) {
if (t->dev->parent != dev)
continue;
-   __nvm_remove_target(t);
+   __nvm_remove_target(t, false);
}
mutex_unlock(>mlock);
 
diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 4b10122aec89..5f1e5b1b3094 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -1461,7 +1461,7 @@ static void pblk_line_close_meta_sync(struct pblk *pblk)
flush_workqueue(pblk->close_wq);
 }
 
-void pblk_pipeline_stop(struct pblk *pblk)
+void __pblk_pipeline_flush(struct pblk *pblk)
 {
struct pblk_line_mgmt *l_mg = >l_mg;
int ret;
@@ -1486,6 +1486,11 @@ void pblk_pipeline_stop(struct pblk *pblk)
 
flush_workqueue(pblk->bb_wq);
pblk_line_close_meta_sync(pblk);
+}
+
+void __pblk_pipeline_stop(struct pblk *pblk)
+{
+   struct pblk_line_mgmt *l_mg = >l_mg;
 
spin_lock(_mg->free_lock);
pblk->state = PBLK_STATE_STOPPED;
@@ -1494,6 +1499,12 @@ void pblk_pipeline_stop(struct pblk *pblk)
spin_unlock(_mg->free_lock);
 }
 
+void pblk_pipeline_stop(struct pblk *pblk)
+{
+   __pblk_pipeline_flush(pblk);
+   __pblk_pipeline_stop(pblk);
+}
+
 struct pblk_line *pblk_line_replace_data(struct pblk *pblk)
 {
struct pblk_line_mgmt *l_mg = >l_mg;
diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index 6851a5c67189..b0cc277bf972 100644
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -649,7 +649,7 @@ int pblk_gc_init(struct pblk *pblk)
return ret;
 }
 
-void pblk_gc_exit(struct pblk *pblk)
+void pblk_gc_exit(struct pblk *pblk, bool graceful)
 {
struct pblk_gc *gc = >gc;
 
@@ -663,10 +663,12 @@ void pblk_gc_exit(struct pblk *pblk)
if (gc->gc_reader_ts)
kthread_stop(gc->gc_reader_ts);
 
-   flush_workqueue(gc->gc_reader_wq);
+   if (graceful) {
+   flush_workqueue(gc->gc_reader_wq);
+   flush_workqueue(gc->gc_line_reader_wq);
+   }
+
destroy_workqueue(gc->gc_reader_wq);
-
-   flush_workqueue(gc->gc_line_reader_wq);
destroy_workqueue(gc->gc_line_reader_wq);
 
if (gc->gc_writer_ts)
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 9e3a43346d4c..bfc488d0dda9 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -1118,23 +1118,25 @@ static void pblk_free(struct pblk *pblk)
kfree(pblk);
 }
 
-static void pblk_tear_down(struct pblk *pblk)
+static void