On Thu, 21 Jan 2021, Denis Efremov wrote:
> I think it's hard to recall the exact reasons after so many years.
Yeah, I guess so :)
> I'll send a patch today based on this one.
I am currently waiting for confirmation by the original reporter that the
patch below fixes the issue.
From: Jiri Kosina <jkosina@xxxxxxx>
Subject: [PATCH] floppy: reintroduce O_NDELAY fix
Originally fixed in 09954bad4 ("floppy: refactor open() flags handling")
then reverted for unknown reason in f2791e7eadf437 instead of taking
the open(O_ACCMODE) for ioctl-only open fix, which had the changelog below
====
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.
Cc: stable@xxxxxxxxxxxxxxx # v4.5+
Reported-by: Wim Osterholt <wim@xxxxxxxxxxxxxx>
Tested-by: Wim Osterholt <wim@xxxxxxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
=====
Fixes: 09954bad4 ("floppy: refactor open() flags handling")
Fixes: f2791e7ead ("Revert "floppy: refactor open() flags handling"")
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
---
drivers/block/floppy.c | 29 ++++++++++++++---------------
1 file changed, 14 insertions(+), 15 deletions(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index dfe1dfc901cc..bda9417aa0a8 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4121,23 +4121,22 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
if (fdc_state[FDC(drive)].rawcmd == 1)
fdc_state[FDC(drive)].rawcmd = 2;
- if (!(mode & FMODE_NDELAY)) {
- if (mode & (FMODE_READ|FMODE_WRITE)) {
- drive_state[drive].last_checked = 0;
- clear_bit(FD_OPEN_SHOULD_FAIL_BIT,
- &drive_state[drive].flags);
- if (bdev_check_media_change(bdev))
- floppy_revalidate(bdev->bd_disk);
- if (test_bit(FD_DISK_CHANGED_BIT, &drive_state[drive].flags))
- goto out;
- if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags))
- goto out;
- }
- res = -EROFS;
- if ((mode & FMODE_WRITE) &&
- !test_bit(FD_DISK_WRITABLE_BIT, &drive_state[drive].flags))
+ if (mode & (FMODE_READ|FMODE_WRITE)) {
+ UDRS->last_checked = 0;
+ clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags);
+ check_disk_change(bdev);
+ if (test_bit(FD_DISK_CHANGED_BIT, &drive_state[drive].flags))
+ goto out;
+ if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags))
goto out;
}
+
+ res = -EROFS;
+
+ if ((mode & FMODE_WRITE) &&
+ !test_bit(FD_DISK_WRITABLE_BIT, &drive_state[drive].flags))
+ goto out;
+
mutex_unlock(&open_lock);
mutex_unlock(&floppy_mutex);
return 0;
--
Jiri Kosina
SUSE Labs
