scsi: replace the fmode_t argument to ->sg_io_fn with a simple bool

Instead of passing a fmode_t and only checking it for FMODE_WRITE, pass
a bool open_for_write to prepare for callers that won't have the fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-21-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/bsg-lib.c

@@ -26,7 +26,7 @@ struct bsg_set {
 };
 
 static int bsg_transport_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
-		fmode_t mode, unsigned int timeout)
+		bool open_for_write, unsigned int timeout)
 {
 	struct bsg_job *job;
 	struct request *rq;

block/bsg.c

@@ -54,7 +54,8 @@ static unsigned int bsg_timeout(struct bsg_device *bd, struct sg_io_v4 *hdr)
 	return max_t(unsigned int, timeout, BLK_MIN_SG_TIMEOUT);
 }
 
-static int bsg_sg_io(struct bsg_device *bd, fmode_t mode, void __user *uarg)
+static int bsg_sg_io(struct bsg_device *bd, bool open_for_write,
+		     void __user *uarg)
 {
 	struct sg_io_v4 hdr;
 	int ret;
@@ -63,7 +64,8 @@ static int bsg_sg_io(struct bsg_device *bd, fmode_t mode, void __user *uarg)
 		return -EFAULT;
 	if (hdr.guard != 'Q')
 		return -EINVAL;
-	ret = bd->sg_io_fn(bd->queue, &hdr, mode, bsg_timeout(bd, &hdr));
+	ret = bd->sg_io_fn(bd->queue, &hdr, open_for_write,
+			   bsg_timeout(bd, &hdr));
 	if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr)))
 		return -EFAULT;
 	return ret;
@@ -146,7 +148,7 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case SG_EMULATED_HOST:
 		return put_user(1, intp);
 	case SG_IO:
-		return bsg_sg_io(bd, file->f_mode, uarg);
+		return bsg_sg_io(bd, file->f_mode & FMODE_WRITE, uarg);
 	case SCSI_IOCTL_SEND_COMMAND:
 		pr_warn_ratelimited("%s: calling unsupported SCSI_IOCTL_SEND_COMMAND\n",
 				current->comm);

drivers/scsi/scsi_bsg.c

@@ -10,7 +10,7 @@
 #define uptr64(val) ((void __user *)(uintptr_t)(val))
 
 static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
-		fmode_t mode, unsigned int timeout)
+		bool open_for_write, unsigned int timeout)
 {
 	struct scsi_cmnd *scmd;
 	struct request *rq;
@@ -42,7 +42,7 @@ static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
 	if (copy_from_user(scmd->cmnd, uptr64(hdr->request), scmd->cmd_len))
 		goto out_put_request;
 	ret = -EPERM;
-	if (!scsi_cmd_allowed(scmd->cmnd, mode & FMODE_WRITE))
+	if (!scsi_cmd_allowed(scmd->cmnd, open_for_write))
 		goto out_put_request;
 
 	ret = 0;

include/linux/bsg.h

@@ -9,7 +9,7 @@ struct device;
 struct request_queue;
 
 typedef int (bsg_sg_io_fn)(struct request_queue *, struct sg_io_v4 *hdr,
-		fmode_t mode, unsigned int timeout);
+		bool open_for_write, unsigned int timeout);
 
 struct bsg_device *bsg_register_queue(struct request_queue *q,
 		struct device *parent, const char *name,