Commit 8a0c014c authored by Jiri Kosina's avatar Jiri Kosina Committed by Denis Efremov
Browse files

floppy: reintroduce O_NDELAY fix 

This issue was originally fixed in 09954bad ("floppy: refactor open()
flags handling").

The fix as a side-effect, however, introduce issue for open(O_ACCMODE)
that is being used for ioctl-only open. I wrote a fix for that, but
instead of it being merged, full revert of 09954bad was performed,
re-introducing the O_NDELAY / O_NONBLOCK issue, and it strikes again.

This is a forward-port of the original fix to current codebase; the
original submission had the changelog below:

====
Commit 09954bad ("floppy: refactor open() flags handling"), as a
side-effect, causes open(/dev/fdX, O_ACCMODE) to fail. It turns out that
this is being used setfdprm userspace for ioctl-only open().

Reintroduce back the original behavior wrt !(FMODE_READ|FMODE_WRITE)
modes, while still keeping the original O_NDELAY bug fixed.

Link: https://lore.kernel.org/r/nycvar.YFH.7.76.2101221209060.5622@cbobk.fhfr.pm


Cc: stable@vger.kernel.org
Reported-by: default avatarWim Osterholt <wim@djo.tudelft.nl>
Tested-by: default avatarWim Osterholt <wim@djo.tudelft.nl>
Reported-and-tested-by: default avatarKurt Garloff <kurt@garloff.de>
Fixes: 09954bad ("floppy: refactor open() flags handling")
Fixes: f2791e7e ("Revert "floppy: refactor open() flags handling"")
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
Signed-off-by: default avatarDenis Efremov <efremov@linux.com>
parent 0d738971

drivers/block/floppy.c

+15 −15
Original line number Original line Diff line number Diff line
@@ -4121,11 +4121,9 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) 
	if (fdc_state[FDC(drive)].rawcmd == 1)

	if (fdc_state[FDC(drive)].rawcmd == 1)

		fdc_state[FDC(drive)].rawcmd = 2;

		fdc_state[FDC(drive)].rawcmd = 2;





	if (!(mode & FMODE_NDELAY)) {

	if (mode & (FMODE_READ|FMODE_WRITE)) {

	if (mode & (FMODE_READ|FMODE_WRITE)) {

		drive_state[drive].last_checked = 0;

		drive_state[drive].last_checked = 0;

			clear_bit(FD_OPEN_SHOULD_FAIL_BIT,

		clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags);

				  &drive_state[drive].flags);

		if (bdev_check_media_change(bdev))

		if (bdev_check_media_change(bdev))

			floppy_revalidate(bdev->bd_disk);

			floppy_revalidate(bdev->bd_disk);

		if (test_bit(FD_DISK_CHANGED_BIT, &drive_state[drive].flags))

		if (test_bit(FD_DISK_CHANGED_BIT, &drive_state[drive].flags))
@@ -4133,11 +4131,13 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) 
		if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags))

		if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags))

			goto out;

			goto out;

	}

	}



	res = -EROFS;

	res = -EROFS;



	if ((mode & FMODE_WRITE) &&

	if ((mode & FMODE_WRITE) &&

			!test_bit(FD_DISK_WRITABLE_BIT, &drive_state[drive].flags))

			!test_bit(FD_DISK_WRITABLE_BIT, &drive_state[drive].flags))

		goto out;

		goto out;

	}



	mutex_unlock(&open_lock);

	mutex_unlock(&open_lock);

	mutex_unlock(&floppy_mutex);

	mutex_unlock(&floppy_mutex);

	return 0;

	return 0;