diff options
| author | Christoph Hellwig <hch@lst.de> | 2022-07-21 16:09:12 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-07-21 19:52:12 +0300 |
| commit | fa362045564ea7641e7d48295b54f4eb4df689ea (patch) | |
| tree | 02bf9349465e65b2a0d3820770782957155173b6 /drivers/block | |
| parent | 49d686cceed2e3148ba2bd2dec7e09b86eba0337 (diff) | |
| download | linux-fa362045564ea7641e7d48295b54f4eb4df689ea.tar.xz | |
ublk: simplify ublk_ch_open and ublk_ch_release
fops->open and fops->release are always paired. Use simple atomic bit
ops ot indicate if the device is opened instead of a count that can
only be 0 and 1 and a useless cmpxchg loop in ublk_ch_release.
Also don't bother clearing file->private_data is the file is about to
be freed anyway.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220721130916.1869719-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/ublk_drv.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index deabcb23ae2a..1f7bbbc3276a 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -125,7 +125,8 @@ struct ublk_device { struct cdev cdev; struct device cdev_dev; - atomic_t ch_open_cnt; +#define UB_STATE_OPEN (1 << 0) + unsigned long state; int ub_number; struct mutex mutex; @@ -647,21 +648,17 @@ static int ublk_ch_open(struct inode *inode, struct file *filp) struct ublk_device *ub = container_of(inode->i_cdev, struct ublk_device, cdev); - if (atomic_cmpxchg(&ub->ch_open_cnt, 0, 1) == 0) { - filp->private_data = ub; - return 0; - } - return -EBUSY; + if (test_and_set_bit(UB_STATE_OPEN, &ub->state)) + return -EBUSY; + filp->private_data = ub; + return 0; } static int ublk_ch_release(struct inode *inode, struct file *filp) { struct ublk_device *ub = filp->private_data; - while (atomic_cmpxchg(&ub->ch_open_cnt, 1, 0) != 1) - cpu_relax(); - - filp->private_data = NULL; + clear_bit(UB_STATE_OPEN, &ub->state); return 0; } |