From: Jiri Kosina <jkosina@xxxxxxx>
commit 8a0c014cd20516ade9654fc13b51345ec58e7be8 upstream.
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.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/floppy.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4069,21 +4069,22 @@ 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;
