On 08/18/2016 09:59 AM, Greg Kroah-Hartman wrote:
4.7-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Kosina <[email protected]>

commit ff06db1efb2ad6db06eb5b99b88a0c15a9cc9b0e upstream.

Commit 09954bad4 ("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.

Reported-by: Wim Osterholt <[email protected]>
Tested-by: Wim Osterholt <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/block/floppy.c |   21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3663,11 +3663,6 @@ static int floppy_open(struct block_devi

        opened_bdev[drive] = bdev;

-       if (!(mode & (FMODE_READ|FMODE_WRITE))) {
-               res = -EINVAL;
-               goto out;
-       }
-
        res = -ENXIO;

        if (!floppy_track_buffer) {
@@ -3711,13 +3706,15 @@ static int floppy_open(struct block_devi
        if (UFDCS->rawcmd == 1)
                UFDCS->rawcmd = 2;

-       UDRS->last_checked = 0;
-       clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags);
-       check_disk_change(bdev);
-       if (test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags))
-               goto out;
-       if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags))
-               goto out;
+       if (mode & (FMODE_READ|FMODE_WRITE)) {
+               UDRS->last_checked = 0;
+               clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags);
+               check_disk_change(bdev);
+               if (test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags))
+                       goto out;
+               if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags))
+                       goto out;
+       }

        res = -EROFS;





I have a problem with this patch. It only fixes one of the regressions caused by the original change to the floppy driver. It does not address the user land breakage of removing the NODELAY flag checks.

Thanks
Mark

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