block/swim3: Fix -EBUSY error when re-opening device after unmount

When the block device is opened with FMODE_EXCL, ref_count is set to -1.
This value doesn't get reset when the device is closed which means the
device cannot be opened again. Fix this by checking for refcount <= 0
in the release method.

Reported-and-tested-by: Stan Johnson <userm57@yahoo.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Finn Thain 2018-12-31 16:44:09 +11:00 committed by Jens Axboe
parent f3010ec5b7
commit 296dcc40f2

View File

@ -995,7 +995,11 @@ static void floppy_release(struct gendisk *disk, fmode_t mode)
struct swim3 __iomem *sw = fs->swim3;
mutex_lock(&swim3_mutex);
if (fs->ref_count > 0 && --fs->ref_count == 0) {
if (fs->ref_count > 0)
--fs->ref_count;
else if (fs->ref_count == -1)
fs->ref_count = 0;
if (fs->ref_count == 0) {
swim3_action(fs, MOTOR_OFF);
out_8(&sw->control_bic, 0xff);
swim3_select(fs, RELAX);