Re: [PATCH] floppy: reintroduce O_NDELAY fix
From: Denis Efremov <efremov@linux.com>
Date: 2021-01-26 17:48:51
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On 1/22/21 2:13 PM, Jiri Kosina wrote:
From: Jiri Kosina <redacted>
This issue was originally fixed in 09954bad4 ("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 09954bad4 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 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@vger.kernel.org
Reported-by: Wim Osterholt <redacted>
Tested-by: Wim Osterholt <redacted>
Reported-and-tested-by: Kurt Garloff <redacted>
Fixes: 09954bad4 ("floppy: refactor open() flags handling")
Fixes: f2791e7ead ("Revert "floppy: refactor open() flags handling"")
Signed-off-by: Jiri Kosina <redacted>Applied. I'll send it to Jens soon with a couple of cleanup patches. https://github.com/evdenis/linux-floppy/commit/e32f6163c47efbdbad06258560aa00d1c7e5b699 Thanks, Denis
quoted hunk ↗ jump to hunk
--- drivers/block/floppy.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-)diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index dfe1dfc901cc..0b71292d9d5a 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c@@ -4121,23 +4121,23 @@ 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)) { + 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)) + goto out; + mutex_unlock(&open_lock); mutex_unlock(&floppy_mutex); return 0;