Merge tag 'for-5.11/drivers-2020-12-14' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "Nothing major in here:

   - NVMe pull request from Christoph:
        - nvmet passthrough improvements (Chaitanya Kulkarni)
        - fcloop error injection support (James Smart)
        - read-only support for zoned namespaces without Zone Append
          (Javier González)
        - improve some error message (Minwoo Im)
        - reject I/O to offline fabrics namespaces (Victor Gladkov)
        - PCI queue allocation cleanups (Niklas Schnelle)
        - remove an unused allocation in nvmet (Amit Engel)
        - a Kconfig spelling fix (Colin Ian King)
        - nvme_req_qid simplication (Baolin Wang)

   - MD pull request from Song:
        - Fix race condition in md_ioctl() (Dae R. Jeong)
        - Initialize read_slot properly for raid10 (Kevin Vigor)
        - Code cleanup (Pankaj Gupta)
        - md-cluster resync/reshape fix (Zhao Heming)

   - Move null_blk into its own directory (Damien Le Moal)

   - null_blk zone and discard improvements (Damien Le Moal)

   - bcache race fix (Dongsheng Yang)

   - Set of rnbd fixes/improvements (Gioh Kim, Guoqing Jiang, Jack Wang,
     Lutz Pogrell, Md Haris Iqbal)

   - lightnvm NULL pointer deref fix (tangzhenhao)

   - sr in_interrupt() removal (Sebastian Andrzej Siewior)

   - FC endpoint security support for s390/dasd (Jan Höppner, Sebastian
     Ott, Vineeth Vijayan). From the s390 arch guys, arch bits included
     as it made it easier for them to funnel the feature through the
     block driver tree.

   - Follow up fixes (Colin Ian King)"

* tag 'for-5.11/drivers-2020-12-14' of git://git.kernel.dk/linux-block: (64 commits)
  block: drop dead assignments in loop_init()
  sr: Remove in_interrupt() usage in sr_init_command().
  sr: Switch the sector size back to 2048 if sr_read_sector() changed it.
  cdrom: Reset sector_size back it is not 2048.
  drivers/lightnvm: fix a null-ptr-deref bug in pblk-core.c
  null_blk: Move driver into its own directory
  null_blk: Allow controlling max_hw_sectors limit
  null_blk: discard zones on reset
  null_blk: cleanup discard handling
  null_blk: Improve implicit zone close
  null_blk: improve zone locking
  block: Align max_hw_sectors to logical blocksize
  null_blk: Fail zone append to conventional zones
  null_blk: Fix zone size initialization
  bcache: fix race between setting bdev state to none and new write request direct to backing
  block/rnbd: fix a null pointer dereference on dev->blk_symlink_name
  block/rnbd-clt: Dynamically alloc buffer for pathname & blk_symlink_name
  block/rnbd: call kobject_put in the failure path
  Documentation/ABI/rnbd-srv: add document for force_close
  block/rnbd-srv: close a mapped device from server side.
  ...

6 files changed, 117 insertions, 30 deletions

diff --git a/drivers/block/rnbd/rnbd-clt-sysfs.c b/drivers/block/rnbd/rnbd-clt-sysfs.c
index 4f4474eecadb..a7caeedeb198 100644
--- a/drivers/block/rnbd/rnbd-clt-sysfs.c
+++ b/drivers/block/rnbd/rnbd-clt-sysfs.c
@@ -37,7 +37,6 @@ enum {
 };
 
 static const unsigned int rnbd_opt_mandatory[] = {
-	RNBD_OPT_PATH,
 	RNBD_OPT_DEV_PATH,
 	RNBD_OPT_SESSNAME,
 };
@@ -435,6 +434,7 @@ void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev)
 	 */
 	if (strlen(dev->blk_symlink_name) && try_module_get(THIS_MODULE)) {
 		sysfs_remove_link(rnbd_devs_kobj, dev->blk_symlink_name);
+		kfree(dev->blk_symlink_name);
 		module_put(THIS_MODULE);
 	}
 }
@@ -451,9 +451,11 @@ static int rnbd_clt_add_dev_kobj(struct rnbd_clt_dev *dev)
 
 	ret = kobject_init_and_add(&dev->kobj, &rnbd_dev_ktype, gd_kobj, "%s",
 				   "rnbd");
-	if (ret)
+	if (ret) {
 		rnbd_clt_err(dev, "Failed to create device sysfs dir, err: %d\n",
 			      ret);
+		kobject_put(&dev->kobj);
+	}
 
 	return ret;
 }
@@ -481,16 +483,27 @@ static int rnbd_clt_get_path_name(struct rnbd_clt_dev *dev, char *buf,
 	if (ret >= len)
 		return -ENAMETOOLONG;
 
+	ret = snprintf(buf, len, "%s@%s", buf, dev->sess->sessname);
+	if (ret >= len)
+		return -ENAMETOOLONG;
+
 	return 0;
 }
 
 static int rnbd_clt_add_dev_symlink(struct rnbd_clt_dev *dev)
 {
 	struct kobject *gd_kobj = &disk_to_dev(dev->gd)->kobj;
-	int ret;
+	int ret, len;
+
+	len = strlen(dev->pathname) + strlen(dev->sess->sessname) + 2;
+	dev->blk_symlink_name = kzalloc(len, GFP_KERNEL);
+	if (!dev->blk_symlink_name) {
+		rnbd_clt_err(dev, "Failed to allocate memory for blk_symlink_name\n");
+		return -ENOMEM;
+	}
 
 	ret = rnbd_clt_get_path_name(dev, dev->blk_symlink_name,
-				      sizeof(dev->blk_symlink_name));
+				      len);
 	if (ret) {
 		rnbd_clt_err(dev, "Failed to get /sys/block symlink path, err: %d\n",
 			      ret);
diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c
index bb13d7dd195a..a199b190c73d 100644
--- a/drivers/block/rnbd/rnbd-clt.c
+++ b/drivers/block/rnbd/rnbd-clt.c
@@ -59,6 +59,7 @@ static void rnbd_clt_put_dev(struct rnbd_clt_dev *dev)
 	ida_simple_remove(&index_ida, dev->clt_device_id);
 	mutex_unlock(&ida_lock);
 	kfree(dev->hw_queues);
+	kfree(dev->pathname);
 	rnbd_clt_put_sess(dev->sess);
 	mutex_destroy(&dev->lock);
 	kfree(dev);
@@ -1192,6 +1193,12 @@ find_and_get_or_create_sess(const char *sessname,
 	else if (!first)
 		return sess;
 
+	if (!path_cnt) {
+		pr_err("Session %s not found, and path parameter not given", sessname);
+		err = -ENXIO;
+		goto put_sess;
+	}
+
 	rtrs_ops = (struct rtrs_clt_ops) {
 		.priv = sess,
 		.link_ev = rnbd_clt_link_ev,
@@ -1380,10 +1387,17 @@ static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess,
 		       pathname, sess->sessname, ret);
 		goto out_queues;
 	}
+
+	dev->pathname = kzalloc(strlen(pathname) + 1, GFP_KERNEL);
+	if (!dev->pathname) {
+		ret = -ENOMEM;
+		goto out_queues;
+	}
+	strlcpy(dev->pathname, pathname, strlen(pathname) + 1);
+
 	dev->clt_device_id	= ret;
 	dev->sess		= sess;
 	dev->access_mode	= access_mode;
-	strlcpy(dev->pathname, pathname, sizeof(dev->pathname));
 	mutex_init(&dev->lock);
 	refcount_set(&dev->refcount, 1);
 	dev->dev_state = DEV_STATE_INIT;
@@ -1403,17 +1417,20 @@ out_alloc:
 	return ERR_PTR(ret);
 }
 
-static bool __exists_dev(const char *pathname)
+static bool __exists_dev(const char *pathname, const char *sessname)
 {
 	struct rnbd_clt_session *sess;
 	struct rnbd_clt_dev *dev;
 	bool found = false;
 
 	list_for_each_entry(sess, &sess_list, list) {
+		if (sessname && strncmp(sess->sessname, sessname,
+					sizeof(sess->sessname)))
+			continue;
 		mutex_lock(&sess->lock);
 		list_for_each_entry(dev, &sess->devs_list, list) {
-			if (!strncmp(dev->pathname, pathname,
-				     sizeof(dev->pathname))) {
+			if (strlen(dev->pathname) == strlen(pathname) &&
+			    !strcmp(dev->pathname, pathname)) {
 				found = true;
 				break;
 			}
@@ -1426,12 +1443,12 @@ static bool __exists_dev(const char *pathname)
 	return found;
 }
 
-static bool exists_devpath(const char *pathname)
+static bool exists_devpath(const char *pathname, const char *sessname)
 {
 	bool found;
 
 	mutex_lock(&sess_lock);
-	found = __exists_dev(pathname);
+	found = __exists_dev(pathname, sessname);
 	mutex_unlock(&sess_lock);
 
 	return found;
@@ -1444,7 +1461,7 @@ static bool insert_dev_if_not_exists_devpath(const char *pathname,
 	bool found;
 
 	mutex_lock(&sess_lock);
-	found = __exists_dev(pathname);
+	found = __exists_dev(pathname, sess->sessname);
 	if (!found) {
 		mutex_lock(&sess->lock);
 		list_add_tail(&dev->list, &sess->devs_list);
@@ -1474,7 +1491,7 @@ struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname,
 	struct rnbd_clt_dev *dev;
 	int ret;
 
-	if (exists_devpath(pathname))
+	if (unlikely(exists_devpath(pathname, sessname)))
 		return ERR_PTR(-EEXIST);
 
 	sess = find_and_get_or_create_sess(sessname, paths, path_cnt, port_nr);
diff --git a/drivers/block/rnbd/rnbd-clt.h b/drivers/block/rnbd/rnbd-clt.h
index ed33654aa486..b193d5904050 100644
--- a/drivers/block/rnbd/rnbd-clt.h
+++ b/drivers/block/rnbd/rnbd-clt.h
@@ -108,7 +108,7 @@ struct rnbd_clt_dev {
 	u32			clt_device_id;
 	struct mutex		lock;
 	enum rnbd_clt_dev_state	dev_state;
-	char			pathname[NAME_MAX];
+	char			*pathname;
 	enum rnbd_access_mode	access_mode;
 	bool			read_only;
 	bool			rotational;
@@ -126,7 +126,7 @@ struct rnbd_clt_dev {
 	struct list_head        list;
 	struct gendisk		*gd;
 	struct kobject		kobj;
-	char			blk_symlink_name[NAME_MAX];
+	char			*blk_symlink_name;
 	refcount_t		refcount;
 	struct work_struct	unmap_on_rmmod_work;
 };
diff --git a/drivers/block/rnbd/rnbd-srv-sysfs.c b/drivers/block/rnbd/rnbd-srv-sysfs.c
index 106775c074d1..05ffe488ddc6 100644
--- a/drivers/block/rnbd/rnbd-srv-sysfs.c
+++ b/drivers/block/rnbd/rnbd-srv-sysfs.c
@@ -47,13 +47,17 @@ int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
 
 	ret = kobject_init_and_add(&dev->dev_kobj, &dev_ktype,
 				   rnbd_devs_kobj, dev_name);
-	if (ret)
+	if (ret) {
+		kobject_put(&dev->dev_kobj);
 		return ret;
+	}
 
 	dev->dev_sessions_kobj = kobject_create_and_add("sessions",
 							&dev->dev_kobj);
-	if (!dev->dev_sessions_kobj)
-		goto put_dev_kobj;
+	if (!dev->dev_sessions_kobj) {
+		ret = -ENOMEM;
+		goto free_dev_kobj;
+	}
 
 	bdev_kobj = &disk_to_dev(bdev->bd_disk)->kobj;
 	ret = sysfs_create_link(&dev->dev_kobj, bdev_kobj, "block_dev");
@@ -64,7 +68,8 @@ int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
 
 put_sess_kobj:
 	kobject_put(dev->dev_sessions_kobj);
-put_dev_kobj:
+free_dev_kobj:
+	kobject_del(&dev->dev_kobj);
 	kobject_put(&dev->dev_kobj);
 	return ret;
 }
@@ -120,10 +125,46 @@ static ssize_t mapping_path_show(struct kobject *kobj,
 static struct kobj_attribute rnbd_srv_dev_session_mapping_path_attr =
 	__ATTR_RO(mapping_path);
 
+static ssize_t rnbd_srv_dev_session_force_close_show(struct kobject *kobj,
+					struct kobj_attribute *attr, char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "Usage: echo 1 > %s\n",
+			 attr->attr.name);
+}
+
+static ssize_t rnbd_srv_dev_session_force_close_store(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					const char *buf, size_t count)
+{
+	struct rnbd_srv_sess_dev *sess_dev;
+
+	sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+
+	if (!sysfs_streq(buf, "1")) {
+		rnbd_srv_err(sess_dev, "%s: invalid value: '%s'\n",
+			      attr->attr.name, buf);
+		return -EINVAL;
+	}
+
+	rnbd_srv_info(sess_dev, "force close requested\n");
+
+	/* first remove sysfs itself to avoid deadlock */
+	sysfs_remove_file_self(&sess_dev->kobj, &attr->attr);
+	rnbd_srv_sess_dev_force_close(sess_dev);
+
+	return count;
+}
+
+static struct kobj_attribute rnbd_srv_dev_session_force_close_attr =
+	__ATTR(force_close, 0644,
+	       rnbd_srv_dev_session_force_close_show,
+	       rnbd_srv_dev_session_force_close_store);
+
 static struct attribute *rnbd_srv_default_dev_sessions_attrs[] = {
 	&rnbd_srv_dev_session_access_mode_attr.attr,
 	&rnbd_srv_dev_session_ro_attr.attr,
 	&rnbd_srv_dev_session_mapping_path_attr.attr,
+	&rnbd_srv_dev_session_force_close_attr.attr,
 	NULL,
 };
 
@@ -145,7 +186,7 @@ static void rnbd_srv_sess_dev_release(struct kobject *kobj)
 	struct rnbd_srv_sess_dev *sess_dev;
 
 	sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
-	rnbd_destroy_sess_dev(sess_dev);
+	rnbd_destroy_sess_dev(sess_dev, sess_dev->keep_id);
 }
 
 static struct kobj_type rnbd_srv_sess_dev_ktype = {
@@ -160,18 +201,17 @@ int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
 	ret = kobject_init_and_add(&sess_dev->kobj, &rnbd_srv_sess_dev_ktype,
 				   sess_dev->dev->dev_sessions_kobj, "%s",
 				   sess_dev->sess->sessname);
-	if (ret)
+	if (ret) {
+		kobject_put(&sess_dev->kobj);
 		return ret;
+	}
 
 	ret = sysfs_create_group(&sess_dev->kobj,
 				 &rnbd_srv_default_dev_session_attr_group);
-	if (ret)
-		goto err;
-
-	return 0;
-
-err:
-	kobject_put(&sess_dev->kobj);
+	if (ret) {
+		kobject_del(&sess_dev->kobj);
+		kobject_put(&sess_dev->kobj);
+	}
 
 	return ret;
 }
diff --git a/drivers/block/rnbd/rnbd-srv.c b/drivers/block/rnbd/rnbd-srv.c
index e1bc8b4cd592..d1ee72ed8384 100644
--- a/drivers/block/rnbd/rnbd-srv.c
+++ b/drivers/block/rnbd/rnbd-srv.c
@@ -212,12 +212,20 @@ static void rnbd_put_srv_dev(struct rnbd_srv_dev *dev)
 	kref_put(&dev->kref, destroy_device_cb);
 }
 
-void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev)
+void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev, bool keep_id)
 {
 	DECLARE_COMPLETION_ONSTACK(dc);
 
-	xa_erase(&sess_dev->sess->index_idr, sess_dev->device_id);
+	if (keep_id)
+		/* free the resources for the id but don't  */
+		/* allow to re-use the id itself because it */
+		/* is still used by the client              */
+		xa_cmpxchg(&sess_dev->sess->index_idr, sess_dev->device_id,
+			   sess_dev, NULL, 0);
+	else
+		xa_erase(&sess_dev->sess->index_idr, sess_dev->device_id);
 	synchronize_rcu();
+
 	sess_dev->destroy_comp = &dc;
 	rnbd_put_sess_dev(sess_dev);
 	wait_for_completion(&dc); /* wait for inflights to drop to zero */
@@ -328,6 +336,13 @@ static int rnbd_srv_link_ev(struct rtrs_srv *rtrs,
 	}
 }
 
+void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev)
+{
+	rnbd_srv_destroy_dev_session_sysfs(sess_dev);
+	sess_dev->keep_id = true;
+
+}
+
 static int process_msg_close(struct rtrs_srv *rtrs,
 			     struct rnbd_srv_session *srv_sess,
 			     void *data, size_t datalen, const void *usr,
diff --git a/drivers/block/rnbd/rnbd-srv.h b/drivers/block/rnbd/rnbd-srv.h
index 5a8544b5e74f..b157371c25ed 100644
--- a/drivers/block/rnbd/rnbd-srv.h
+++ b/drivers/block/rnbd/rnbd-srv.h
@@ -56,6 +56,7 @@ struct rnbd_srv_sess_dev {
 	struct rnbd_srv_dev		*dev;
 	struct kobject                  kobj;
 	u32                             device_id;
+	bool				keep_id;
 	fmode_t                         open_flags;
 	struct kref			kref;
 	struct completion               *destroy_comp;
@@ -63,6 +64,7 @@ struct rnbd_srv_sess_dev {
 	enum rnbd_access_mode		access_mode;
 };
 
+void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev);
 /* rnbd-srv-sysfs.c */
 
 int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
@@ -73,6 +75,6 @@ int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev);
 void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev);
 int rnbd_srv_create_sysfs_files(void);
 void rnbd_srv_destroy_sysfs_files(void);
-void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev);
+void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev, bool keep_id);
 
 #endif /* RNBD_SRV_H */