On Mon, 1 Mar 2021, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
> The patch below does not apply to the 5.4-stable tree. If someone wants
> it applied there, or to any other stable or longterm tree, then please
> email the backport, including the original git commit id to
> <stable@xxxxxxxxxxxxxxx>.
Below is a backport of upstream commit 8a0c014cd20516a taken from SUSE
kernel tree.
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>
=====
Link: https://lore.kernel.org/r/nycvar.YFH.7.76.2101221209060.5622@xxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Wim Osterholt <wim@xxxxxxxxxxxxxx>
Tested-by: Wim Osterholt <wim@xxxxxxxxxxxxxx>
Reported-and-tested-by: Kurt Garloff <kurt@xxxxxxxxxx>
Fixes: 09954bad4 ("floppy: refactor open() flags handling")
Fixes: f2791e7ead ("Revert "floppy: refactor open() flags handling"")
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
---
drivers/block/floppy.c | 29 ++++++++++++++---------------
1 file changed, 14 insertions(+), 15 deletions(-)
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4063,21 +4063,22 @@ static int floppy_open(struct block_devi
if (UFDCS->rawcmd == 1)
UFDCS->rawcmd = 2;
- if (!(mode & FMODE_NDELAY)) {
- 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;
- if ((mode & FMODE_WRITE) &&
- !test_bit(FD_DISK_WRITABLE_BIT, &UDRS->flags))
+ 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;
+
+ if ((mode & FMODE_WRITE) &&
+ !test_bit(FD_DISK_WRITABLE_BIT, &UDRS->flags))
+ goto out;
+
mutex_unlock(&open_lock);
mutex_unlock(&floppy_mutex);
return 0;
--
Jiri Kosina
SUSE Labs
