2018-12-31 05:50:58

by Finn Thain

Subject: [PATCH] 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 <[email protected]>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: [email protected]
Signed-off-by: Finn Thain <[email protected]>
---
drivers/block/swim3.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index ba1190f1276b..87ca8f207c7c 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -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);
--
2.19.2

2018-12-31 18:50:49

by Jens Axboe

Subject: Re: [PATCH] block/swim3: Fix -EBUSY error when re-opening device after unmount

On 12/30/18 10:44 PM, Finn Thain wrote:
> 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.

Applied, thanks.


--
Jens Axboe