From: Denis Efremov efremov@linux.com
stable inclusion from linux-4.19.206 commit 61b224e29ec37cbf39111270f2c7143bfe222b20
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commit c7e9d0020361f4308a70cdfd6d5335e273eb8717 upstream.
The patch breaks userspace implementations (e.g. fdutils) and introduces regressions in behaviour. Previously, it was possible to O_NDELAY open a floppy device with no media inserted or with write protected media without an error. Some userspace tools use this particular behavior for probing.
It's not the first time when we revert this patch. Previous revert is in commit f2791e7eadf4 (Revert "floppy: refactor open() flags handling").
This reverts commit 8a0c014cd20516ade9654fc13b51345ec58e7be8.
Link: https://lore.kernel.org/linux-block/de10cb47-34d1-5a88-7751-225ca380f735@com... Reported-by: Mark Hounschell markh@compro.net Cc: Jiri Kosina jkosina@suse.cz Cc: Wim Osterholt wim@djo.tudelft.nl Cc: Kurt Garloff kurt@garloff.de Cc: stable@vger.kernel.org Signed-off-by: Denis Efremov efremov@linux.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/block/floppy.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 04383f14c74a9..8f444b375761c 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4074,22 +4074,21 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) if (UFDCS->rawcmd == 1) UFDCS->rawcmd = 2;
- 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)) + 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)) 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;