Resize ioctl

fuse_i.h

@@ -282,6 +282,7 @@ int fuse_restart_requests(struct fuse_conn *fc);
 ssize_t pxd_add(struct fuse_conn *fc, struct pxd_add_ext_out *add);
 ssize_t pxd_remove(struct fuse_conn *fc, struct pxd_remove_out *remove);
 ssize_t pxd_update_size(struct fuse_conn *fc, struct pxd_update_size_out *update_size);
+ssize_t pxd_ioc_update_size(struct fuse_conn *fc, struct pxd_update_size_out *update_size);
 ssize_t pxd_read_init(struct fuse_conn *fc, struct iov_iter *iter);
 
 // fastpath extension

pxd.c

@@ -146,6 +146,32 @@ static long pxd_ioctl_init(struct file *file, void __user *argp)
 	return pxd_read_init(&ctx->fc, &iter);
 }
 
+static long pxd_ioctl_resize(struct file *file, void __user *argp)
+{
+	struct pxd_context *ctx = NULL;
+	struct pxd_update_size_out update_args;
+	long ret = 0;
+
+	if (copy_from_user(&update_args, argp, sizeof(update_args))) {
+		return -EFAULT;
+	}
+
+	if (!ctx || ctx->id >= pxd_num_contexts_exported) {
+		return -EFAULT;
+	}
+
+	ctx =  &pxd_contexts[update_args.context_id];
+	if (update_args.context_id >= pxd_num_contexts_exported) {
+		printk("%s : invalid context: %d\n", __func__, update_args.context_id);
+		return -EFAULT;
+	}
+
+	printk(KERN_ALERT "%s: id: %llu size: %lu ctx_id: %d\n", __func__,
+		update_args.dev_id, update_args.size, update_args.context_id);
+	ret = pxd_ioc_update_size(&ctx->fc, &update_args);
+	return ret;
+}
+
 static long pxd_ioctl_run_user_queue(struct file *file)
 {
 	struct pxd_context *ctx = container_of(file->f_op, struct pxd_context, fops);
@@ -183,6 +209,8 @@ static long pxd_control_ioctl(struct file *file, unsigned int cmd, unsigned long
 		return pxd_ioctl_init(file, (void __user *)arg);
 	case PXD_IOC_RUN_USER_QUEUE:
 		return pxd_ioctl_run_user_queue(file);
+	case PXD_IOC_RESIZE:
+		return pxd_ioctl_resize(file, (void __user *)arg);
 	default:
 		return -ENOTTY;
 	}
@@ -1023,6 +1051,11 @@ ssize_t pxd_remove(struct fuse_conn *fc, struct pxd_remove_out *remove)
 }
 
 ssize_t pxd_update_size(struct fuse_conn *fc, struct pxd_update_size_out *update_size)
+{
+	return -EOPNOTSUPP;
+}
+
+ssize_t pxd_ioc_update_size(struct fuse_conn *fc, struct pxd_update_size_out *update_size)
 {
 	bool found = false;
 	struct pxd_context *ctx = container_of(fc, struct pxd_context, fc);
@@ -1044,6 +1077,11 @@ ssize_t pxd_update_size(struct fuse_conn *fc, struct pxd_update_size_out *update
 		goto out;
 	}
 
+	if (update_size->size < pxd_dev->size) {
+		spin_unlock(&pxd_dev->lock);
+		err = -EINVAL;
+		goto out;
+	}
 	(void)get_device(&pxd_dev->dev);
 
 	set_capacity(pxd_dev->disk, update_size->size / SECTOR_SIZE);

pxd.h

@@ -20,7 +20,7 @@
 #define PXD_DEV  	"pxd/pxd"		/**< block device prefix */
 #define PXD_DEV_PATH	"/dev/" PXD_DEV		/**< block device path prefix */
 
-#define PXD_VERSION 10				/**< driver version */
+#define PXD_VERSION 11				/**< driver version */
 
 #define PXD_NUM_CONTEXTS			11	/**< Total available control devices */
 #define PXD_NUM_CONTEXT_EXPORTED	1	/**< Available for external use */
@@ -30,9 +30,10 @@
 #define PXD_IOC_GET_VERSION	_IO(PXD_IOCTL_MAGIC, 2)		/* 0x505802 */
 #define PXD_IOC_INIT		_IO(PXD_IOCTL_MAGIC, 3)		/* 0x505803 */
 #define PXD_IOC_RUN_USER_QUEUE	_IO(PXD_IOCTL_MAGIC, 4)		/* 0x505804 */
-#define PXD_IOC_RUN_IO_QUEUE	_IO(PXD_IOCTL_MAGIC, 5)
-#define PXD_IOC_REGISTER_FILE	_IO(PXD_IOCTL_MAGIC, 6)
-#define PXD_IOC_UNREGISTER_FILE	_IO(PXD_IOCTL_MAGIC, 7)
+#define PXD_IOC_RUN_IO_QUEUE	_IO(PXD_IOCTL_MAGIC, 5)		/* 0x505805 */
+#define PXD_IOC_REGISTER_FILE	_IO(PXD_IOCTL_MAGIC, 6)		/* 0x505806 */
+#define PXD_IOC_UNREGISTER_FILE	_IO(PXD_IOCTL_MAGIC, 7)		/* 0x505807 */
+#define PXD_IOC_RESIZE			_IO(PXD_IOCTL_MAGIC, 8)		/* 0x505808 */
 
 #define PXD_MAX_DEVICES	512			/**< maximum number of devices supported */
 #define PXD_MAX_IO		(1024*1024)	/**< maximum io size in bytes */
@@ -155,11 +156,12 @@ struct pxd_read_data_out {
 };
 
 /**
- * PXD_UPDATE_SIZE request from user space
+ * PXD_UPDATE_SIZE ioctl from user space
  */
 struct pxd_update_size_out {
 	uint64_t dev_id;
 	size_t size;
+	int context_id;
 };
 
 /**