block: replace fmode_t with a block-specific type for block open flags

The only overlap between the block open flags mapped into the fmode_t and
other uses of fmode_t are FMODE_READ and FMODE_WRITE.  Define a new
blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and
->ioctl and stop abusing fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com>		[rnbd]
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Christoph Hellwig

arch/um/drivers/ubd_kern.c

@@ -108,9 +108,9 @@ static inline void ubd_set_bit(__u64 bit, unsigned char *data)
 static DEFINE_MUTEX(ubd_lock);
 static DEFINE_MUTEX(ubd_mutex); /* replaces BKL, might not be needed */
 
-static int ubd_open(struct gendisk *disk, fmode_t mode);
+static int ubd_open(struct gendisk *disk, blk_mode_t mode);
 static void ubd_release(struct gendisk *disk);
-static int ubd_ioctl(struct block_device *bdev, fmode_t mode,
+static int ubd_ioctl(struct block_device *bdev, blk_mode_t mode,
 		     unsigned int cmd, unsigned long arg);
 static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo);
 
@@ -1154,7 +1154,7 @@ static int __init ubd_driver_init(void){
 
 device_initcall(ubd_driver_init);
 
-static int ubd_open(struct gendisk *disk, fmode_t mode)
+static int ubd_open(struct gendisk *disk, blk_mode_t mode)
 {
 	struct ubd *ubd_dev = disk->private_data;
 	int err = 0;
@@ -1389,7 +1389,7 @@ static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return 0;
 }
 
-static int ubd_ioctl(struct block_device *bdev, fmode_t mode,
+static int ubd_ioctl(struct block_device *bdev, blk_mode_t mode,
 		     unsigned int cmd, unsigned long arg)
 {
 	struct ubd *ubd_dev = bdev->bd_disk->private_data;

arch/xtensa/platforms/iss/simdisk.c

@@ -120,7 +120,7 @@ static void simdisk_submit_bio(struct bio *bio)
 	bio_endio(bio);
 }
 
-static int simdisk_open(struct gendisk *disk, fmode_t mode)
+static int simdisk_open(struct gendisk *disk, blk_mode_t mode)
 {
 	struct simdisk *dev = disk->private_data;
 

block/bdev.c

@@ -93,22 +93,22 @@ EXPORT_SYMBOL(invalidate_bdev);
  * Drop all buffers & page cache for given bdev range. This function bails
  * with error if bdev has other exclusive owner (such as filesystem).
  */
-int truncate_bdev_range(struct block_device *bdev, fmode_t mode,
+int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode,
 			loff_t lstart, loff_t lend)
 {
 	/*
 	 * If we don't hold exclusive handle for the device, upgrade to it
 	 * while we discard the buffer cache to avoid discarding buffers
 	 * under live filesystem.
 	 */
-	if (!(mode & FMODE_EXCL)) {
+	if (!(mode & BLK_OPEN_EXCL)) {
 		int err = bd_prepare_to_claim(bdev, truncate_bdev_range, NULL);
 		if (err)
 			goto invalidate;
 	}
 
 	truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend);
-	if (!(mode & FMODE_EXCL))
+	if (!(mode & BLK_OPEN_EXCL))
 		bd_abort_claiming(bdev, truncate_bdev_range);
 	return 0;
 
@@ -647,7 +647,7 @@ static void blkdev_flush_mapping(struct block_device *bdev)
 	bdev_write_inode(bdev);
 }
 
-static int blkdev_get_whole(struct block_device *bdev, fmode_t mode)
+static int blkdev_get_whole(struct block_device *bdev, blk_mode_t mode)
 {
 	struct gendisk *disk = bdev->bd_disk;
 	int ret;
@@ -679,7 +679,7 @@ static void blkdev_put_whole(struct block_device *bdev)
 		bdev->bd_disk->fops->release(bdev->bd_disk);
 }
 
-static int blkdev_get_part(struct block_device *part, fmode_t mode)
+static int blkdev_get_part(struct block_device *part, blk_mode_t mode)
 {
 	struct gendisk *disk = part->bd_disk;
 	int ret;
@@ -743,11 +743,11 @@ void blkdev_put_no_open(struct block_device *bdev)
 {
 	put_device(&bdev->bd_device);
 }
-
+	
 /**
  * blkdev_get_by_dev - open a block device by device number
  * @dev: device number of block device to open
- * @mode: FMODE_* mask
+ * @mode: open mode (BLK_OPEN_*)
  * @holder: exclusive holder identifier
  * @hops: holder operations
  *
@@ -765,7 +765,7 @@ void blkdev_put_no_open(struct block_device *bdev)
  * RETURNS:
  * Reference to the block_device on success, ERR_PTR(-errno) on failure.
  */
-struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder,
+struct block_device *blkdev_get_by_dev(dev_t dev, blk_mode_t mode, void *holder,
 		const struct blk_holder_ops *hops)
 {
 	bool unblock_events = true;
@@ -775,8 +775,8 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder,
 
 	ret = devcgroup_check_permission(DEVCG_DEV_BLOCK,
 			MAJOR(dev), MINOR(dev),
-			((mode & FMODE_READ) ? DEVCG_ACC_READ : 0) |
-			((mode & FMODE_WRITE) ? DEVCG_ACC_WRITE : 0));
+			((mode & BLK_OPEN_READ) ? DEVCG_ACC_READ : 0) |
+			((mode & BLK_OPEN_WRITE) ? DEVCG_ACC_WRITE : 0));
 	if (ret)
 		return ERR_PTR(ret);
 
@@ -786,12 +786,12 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder,
 	disk = bdev->bd_disk;
 
 	if (holder) {
-		mode |= FMODE_EXCL;
+		mode |= BLK_OPEN_EXCL;
 		ret = bd_prepare_to_claim(bdev, holder, hops);
 		if (ret)
 			goto put_blkdev;
 	} else {
-		if (WARN_ON_ONCE(mode & FMODE_EXCL)) {
+		if (WARN_ON_ONCE(mode & BLK_OPEN_EXCL)) {
 			ret = -EIO;
 			goto put_blkdev;
 		}
@@ -821,7 +821,7 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder,
 		 * writeable reference is too fragile given the way @mode is
 		 * used in blkdev_get/put().
 		 */
-		if ((mode & FMODE_WRITE) && !bdev->bd_write_holder &&
+		if ((mode & BLK_OPEN_WRITE) && !bdev->bd_write_holder &&
 		    (disk->event_flags & DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE)) {
 			bdev->bd_write_holder = true;
 			unblock_events = false;
@@ -848,7 +848,7 @@ EXPORT_SYMBOL(blkdev_get_by_dev);
 /**
  * blkdev_get_by_path - open a block device by name
  * @path: path to the block device to open
- * @mode: FMODE_* mask
+ * @mode: open mode (BLK_OPEN_*)
  * @holder: exclusive holder identifier
  *
  * Open the block device described by the device file at @path.  If @holder is
@@ -861,7 +861,7 @@ EXPORT_SYMBOL(blkdev_get_by_dev);
  * RETURNS:
  * Reference to the block_device on success, ERR_PTR(-errno) on failure.
  */
-struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
+struct block_device *blkdev_get_by_path(const char *path, blk_mode_t mode,
 		void *holder, const struct blk_holder_ops *hops)
 {
 	struct block_device *bdev;
@@ -873,7 +873,7 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
 		return ERR_PTR(error);
 
 	bdev = blkdev_get_by_dev(dev, mode, holder, hops);
-	if (!IS_ERR(bdev) && (mode & FMODE_WRITE) && bdev_read_only(bdev)) {
+	if (!IS_ERR(bdev) && (mode & BLK_OPEN_WRITE) && bdev_read_only(bdev)) {
 		blkdev_put(bdev, holder);
 		return ERR_PTR(-EACCES);
 	}

block/blk-zoned.c

@@ -356,8 +356,8 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
 	return 0;
 }
 
-static int blkdev_truncate_zone_range(struct block_device *bdev, fmode_t mode,
-				      const struct blk_zone_range *zrange)
+static int blkdev_truncate_zone_range(struct block_device *bdev,
+		blk_mode_t mode, const struct blk_zone_range *zrange)
 {
 	loff_t start, end;
 
@@ -376,7 +376,7 @@ static int blkdev_truncate_zone_range(struct block_device *bdev, fmode_t mode,
  * BLKRESETZONE, BLKOPENZONE, BLKCLOSEZONE and BLKFINISHZONE ioctl processing.
  * Called from blkdev_ioctl.
  */
-int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
+int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
 			   unsigned int cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
@@ -390,7 +390,7 @@ int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
 	if (!bdev_is_zoned(bdev))
 		return -ENOTTY;
 
-	if (!(mode & FMODE_WRITE))
+	if (!(mode & BLK_OPEN_WRITE))
 		return -EBADF;
 
 	if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))

block/blk.h

@@ -396,7 +396,7 @@ void disk_free_zone_bitmaps(struct gendisk *disk);
 void disk_clear_zone_settings(struct gendisk *disk);
 int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
 		unsigned long arg);
-int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
+int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
 		unsigned int cmd, unsigned long arg);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline void disk_free_zone_bitmaps(struct gendisk *disk) {}
@@ -407,7 +407,7 @@ static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
 	return -ENOTTY;
 }
 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
-		fmode_t mode, unsigned int cmd, unsigned long arg)
+		blk_mode_t mode, unsigned int cmd, unsigned long arg)
 {
 	return -ENOTTY;
 }
@@ -451,7 +451,7 @@ static inline void bio_release_page(struct bio *bio, struct page *page)
 
 struct request_queue *blk_alloc_queue(int node_id);
 
-int disk_scan_partitions(struct gendisk *disk, fmode_t mode);
+int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode);
 
 int disk_alloc_events(struct gendisk *disk);
 void disk_add_events(struct gendisk *disk);
@@ -466,8 +466,9 @@ extern struct device_attribute dev_attr_events_poll_msecs;
 
 extern struct attribute_group blk_trace_attr_group;
 
-int truncate_bdev_range(struct block_device *bdev, fmode_t mode, loff_t lstart,
-		loff_t lend);
+blk_mode_t file_to_blk_mode(struct file *file);
+int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode,
+		loff_t lstart, loff_t lend);
 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
 

block/fops.c

@@ -470,6 +470,30 @@ static int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
 	return error;
 }
 
+blk_mode_t file_to_blk_mode(struct file *file)
+{
+	blk_mode_t mode = 0;
+
+	if (file->f_mode & FMODE_READ)
+		mode |= BLK_OPEN_READ;
+	if (file->f_mode & FMODE_WRITE)
+		mode |= BLK_OPEN_WRITE;
+	if (file->f_mode & FMODE_EXCL)
+		mode |= BLK_OPEN_EXCL;
+	if (file->f_flags & O_NDELAY)
+		mode |= BLK_OPEN_NDELAY;
+
+	/*
+	 * If all bits in O_ACCMODE set (aka O_RDWR | O_WRONLY), the floppy
+	 * driver has historically allowed ioctls as if the file was opened for
+	 * writing, but does not allow and actual reads or writes.
+	 */
+	if ((file->f_flags & O_ACCMODE) == (O_RDWR | O_WRONLY))
+		mode |= BLK_OPEN_WRITE_IOCTL;
+
+	return mode;
+}
+
 static int blkdev_open(struct inode *inode, struct file *filp)
 {
 	struct block_device *bdev;
@@ -483,14 +507,10 @@ static int blkdev_open(struct inode *inode, struct file *filp)
 	filp->f_flags |= O_LARGEFILE;
 	filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
 
-	if (filp->f_flags & O_NDELAY)
-		filp->f_mode |= FMODE_NDELAY;
 	if (filp->f_flags & O_EXCL)
 		filp->f_mode |= FMODE_EXCL;
-	if ((filp->f_flags & O_ACCMODE) == 3)
-		filp->f_mode |= FMODE_WRITE_IOCTL;
 
-	bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode,
+	bdev = blkdev_get_by_dev(inode->i_rdev, file_to_blk_mode(filp),
 				 (filp->f_mode & FMODE_EXCL) ? filp : NULL,
 				 NULL);
 	if (IS_ERR(bdev))
@@ -648,7 +668,7 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
 	filemap_invalidate_lock(inode->i_mapping);
 
 	/* Invalidate the page cache, including dirty pages. */
-	error = truncate_bdev_range(bdev, file->f_mode, start, end);
+	error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end);
 	if (error)
 		goto fail;
 

block/genhd.c

@@ -339,7 +339,7 @@ void disk_uevent(struct gendisk *disk, enum kobject_action action)
 }
 EXPORT_SYMBOL_GPL(disk_uevent);
 
-int disk_scan_partitions(struct gendisk *disk, fmode_t mode)
+int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode)
 {
 	struct block_device *bdev;
 	int ret = 0;
@@ -357,7 +357,7 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode)
 	 * synchronize with other exclusive openers and other partition
 	 * scanners.
 	 */
-	if (!(mode & FMODE_EXCL)) {
+	if (!(mode & BLK_OPEN_EXCL)) {
 		ret = bd_prepare_to_claim(disk->part0, disk_scan_partitions,
 					  NULL);
 		if (ret)
@@ -377,7 +377,7 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode)
 	 * creat partition for underlying disk.
 	 */
 	clear_bit(GD_NEED_PART_SCAN, &disk->state);
-	if (!(mode & FMODE_EXCL))
+	if (!(mode & BLK_OPEN_EXCL))
 		bd_abort_claiming(disk->part0, disk_scan_partitions);
 	return ret;
 }
@@ -505,7 +505,7 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
 
 		bdev_add(disk->part0, ddev->devt);
 		if (get_capacity(disk))
-			disk_scan_partitions(disk, FMODE_READ);
+			disk_scan_partitions(disk, BLK_OPEN_READ);
 
 		/*
 		 * Announce the disk and partitions after all partitions are