Unverified Commit 321de651 authored by Christian Brauner's avatar Christian Brauner
Browse files

block: don't rely on BLK_OPEN_RESTRICT_WRITES when yielding write access 

Make it possible to detected a block device that was opened with
restricted write access based only on BLK_OPEN_WRITE and
bdev->bd_writers < 0 so we won't have to claim another FMODE_* flag.

Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-31-adbd023e19cc@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 7c09a4ed

block/bdev.c

+11 −6
Original line number Diff line number Diff line
@@ -799,17 +799,22 @@ static void bdev_claim_write_access(struct block_device *bdev, blk_mode_t mode) 
		bdev->bd_writers++;

}



static void bdev_yield_write_access(struct block_device *bdev, blk_mode_t mode)

static void bdev_yield_write_access(struct file *bdev_file, blk_mode_t mode)

{

	struct block_device *bdev;



	if (bdev_allow_write_mounted)

		return;



	bdev = file_bdev(bdev_file);

	/* Yield exclusive or shared write access. */

	if (mode & BLK_OPEN_RESTRICT_WRITES)

	if (mode & BLK_OPEN_WRITE) {

		if (bdev_writes_blocked(bdev))

			bdev_unblock_writes(bdev);

	else if (mode & BLK_OPEN_WRITE)

		else

			bdev->bd_writers--;

	}

}



/**

 * bdev_open - open a block device
@@ -1020,7 +1025,7 @@ void bdev_release(struct file *bdev_file) 
		sync_blockdev(bdev);



	mutex_lock(&disk->open_mutex);

	bdev_yield_write_access(bdev, handle->mode);

	bdev_yield_write_access(bdev_file, handle->mode);



	if (handle->holder)

		bd_end_claim(bdev, handle->holder);