lightnvm: pass flag on graceful teardown to targets

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 <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 63171cdce2701dc8648e756fe3b51c3d690279f2..60aa7bc5a6302fcc4bd4229076a50d94ae5e68c8 100644 (file)
--- 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 @@ err_reserve:
        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(&dev->mlock);
                return 1;
        }
-       __nvm_remove_target(t);
+       __nvm_remove_target(t, true);
        mutex_unlock(&dev->mlock);
 
        return 0;
@@ -963,7 +963,7 @@ void nvm_unregister(struct nvm_dev *dev)
        list_for_each_entry_safe(t, tmp, &dev->targets, list) {
                if (t->dev->parent != dev)
                        continue;
-               __nvm_remove_target(t);
+               __nvm_remove_target(t, false);
        }
        mutex_unlock(&dev->mlock);
 

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 26f3c14ad799563b5164d99cd423794a29e5cdf6..6e6a65b278b9d7c890788127d9dbd9ad4fa6a2fa 100644 (file)
--- 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 = &pblk->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 = &pblk->l_mg;
 
        spin_lock(&l_mg->free_lock);
        pblk->state = PBLK_STATE_STOPPED;
@@ -1494,6 +1499,12 @@ void pblk_pipeline_stop(struct pblk *pblk)
        spin_unlock(&l_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 = &pblk->l_mg;

diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index 6851a5c6718910af85cf57783c4de3e371dd26a7..b0cc277bf972924aabf85bcc00112a7ba3958b56 100644 (file)
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -649,7 +649,7 @@ fail_free_main_kthread:
        return ret;
 }
 
-void pblk_gc_exit(struct pblk *pblk)
+void pblk_gc_exit(struct pblk *pblk, bool graceful)
 {
        struct pblk_gc *gc = &pblk->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);
-       destroy_workqueue(gc->gc_reader_wq);
+       if (graceful) {
+               flush_workqueue(gc->gc_reader_wq);
+               flush_workqueue(gc->gc_line_reader_wq);
+       }
 
-       flush_workqueue(gc->gc_line_reader_wq);
+       destroy_workqueue(gc->gc_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 81c103b341bd618564430b7cca1c00ae5a01711e..f47e95c0e5da0f54aa79c7e4fa296451178f6004 100644 (file)
--- 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 pblk_tear_down(struct pblk *pblk, bool graceful)
 {
-       pblk_pipeline_stop(pblk);
+       if (graceful)
+               __pblk_pipeline_flush(pblk);
+       __pblk_pipeline_stop(pblk);
        pblk_writer_stop(pblk);
        pblk_rb_sync_l2p(&pblk->rwb);
        pblk_rl_free(&pblk->rl);
 
-       pr_debug("pblk: consistent tear down\n");
+       pr_debug("pblk: consistent tear down (graceful:%d)\n", graceful);
 }
 
-static void pblk_exit(void *private)
+static void pblk_exit(void *private, bool graceful)
 {
        struct pblk *pblk = private;
 
        down_write(&pblk_lock);
-       pblk_gc_exit(pblk);
-       pblk_tear_down(pblk);
+       pblk_gc_exit(pblk, graceful);
+       pblk_tear_down(pblk, graceful);
 
 #ifdef CONFIG_NVM_DEBUG
        pr_info("pblk exit: L2P CRC: %x\n", pblk_l2p_crc(pblk));

diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 97c0dd5f4857347585fcf540ee020dae08727ac0..2399db1b479addcb61bceb3c1c064894d3d924e8 100644 (file)
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -771,6 +771,8 @@ void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line);
 void pblk_line_close(struct pblk *pblk, struct pblk_line *line);
 void pblk_line_close_ws(struct work_struct *work);
 void pblk_pipeline_stop(struct pblk *pblk);
+void __pblk_pipeline_stop(struct pblk *pblk);
+void __pblk_pipeline_flush(struct pblk *pblk);
 void pblk_gen_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
                     void (*work)(struct work_struct *), gfp_t gfp_mask,
                     struct workqueue_struct *wq);
@@ -864,7 +866,7 @@ int pblk_recov_setup_rq(struct pblk *pblk, struct pblk_c_ctx *c_ctx,
 #define PBLK_GC_RSV_LINE 1     /* Reserved lines for GC */
 
 int pblk_gc_init(struct pblk *pblk);
-void pblk_gc_exit(struct pblk *pblk);
+void pblk_gc_exit(struct pblk *pblk, bool graceful);
 void pblk_gc_should_start(struct pblk *pblk);
 void pblk_gc_should_stop(struct pblk *pblk);
 void pblk_gc_should_kick(struct pblk *pblk);

diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index 6e0859b9d4d2ffdc43c1234e8f0ffbd53f45556a..e9e0d1c7eaf5e0737166ef9cde82d91d0b1efd60 100644 (file)
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -489,7 +489,7 @@ typedef blk_qc_t (nvm_tgt_make_rq_fn)(struct request_queue *, struct bio *);
 typedef sector_t (nvm_tgt_capacity_fn)(void *);
 typedef void *(nvm_tgt_init_fn)(struct nvm_tgt_dev *, struct gendisk *,
                                int flags);
-typedef void (nvm_tgt_exit_fn)(void *);
+typedef void (nvm_tgt_exit_fn)(void *, bool);
 typedef int (nvm_tgt_sysfs_init_fn)(struct gendisk *);
 typedef void (nvm_tgt_sysfs_exit_fn)(struct gendisk *);