| Message ID | 20220718063410.338626-11-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/10] md: fix mddev->kobj lifetime | expand |
On 7/18/22 08:34, Christoph Hellwig wrote: > Now that devices are on the all_mddevs list until the gendisk is freed, > there can't be any duplicates. Remove the global list lookup and just > grab a reference. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/md/md.c | 42 +++++++++++++++--------------------------- > 1 file changed, 15 insertions(+), 27 deletions(-) > > diff --git a/drivers/md/md.c b/drivers/md/md.c > index 08cf21ad4c2d7..9b1e61b4bac8b 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -7785,45 +7785,33 @@ static int md_set_read_only(struct block_device *bdev, bool ro) > > static int md_open(struct block_device *bdev, fmode_t mode) > { > - /* > - * Succeed if we can lock the mddev, which confirms that > - * it isn't being stopped right now. > - */ > - struct mddev *mddev = mddev_find(bdev->bd_dev); > + struct mddev *mddev; > int err; > > + spin_lock(&all_mddevs_lock); > + mddev = mddev_get(bdev->bd_disk->private_data); > + spin_unlock(&all_mddevs_lock); > if (!mddev) > return -ENODEV; > > - if (mddev->gendisk != bdev->bd_disk) { > - /* we are racing with mddev_put which is discarding this > - * bd_disk. > - */ > - mddev_put(mddev); > - /* Wait until bdev->bd_disk is definitely gone */ > - if (work_pending(&mddev->del_work)) > - flush_workqueue(md_misc_wq); > - return -EBUSY; > - } > - BUG_ON(mddev != bdev->bd_disk->private_data); > - > - if ((err = mutex_lock_interruptible(&mddev->open_mutex))) > + err = mutex_lock_interruptible(&mddev->open_mutex); > + if (err) > goto out; > > - if (test_bit(MD_CLOSING, &mddev->flags)) { > - mutex_unlock(&mddev->open_mutex); > - err = -ENODEV; > - goto out; > - } > + err = -ENODEV; > + if (test_bit(MD_CLOSING, &mddev->flags)) > + goto out_unlock; > > - err = 0; > atomic_inc(&mddev->openers); > mutex_unlock(&mddev->open_mutex); > > bdev_check_media_change(bdev); > - out: > - if (err) > - mddev_put(mddev); > + return 0; > + > +out_unlock: > + mutex_unlock(&mddev->open_mutex); > +out: > + mddev_put(mddev); > return err; > } > Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes
diff --git a/drivers/md/md.c b/drivers/md/md.c index 08cf21ad4c2d7..9b1e61b4bac8b 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7785,45 +7785,33 @@ static int md_set_read_only(struct block_device *bdev, bool ro) static int md_open(struct block_device *bdev, fmode_t mode) { - /* - * Succeed if we can lock the mddev, which confirms that - * it isn't being stopped right now. - */ - struct mddev *mddev = mddev_find(bdev->bd_dev); + struct mddev *mddev; int err; + spin_lock(&all_mddevs_lock); + mddev = mddev_get(bdev->bd_disk->private_data); + spin_unlock(&all_mddevs_lock); if (!mddev) return -ENODEV; - if (mddev->gendisk != bdev->bd_disk) { - /* we are racing with mddev_put which is discarding this - * bd_disk. - */ - mddev_put(mddev); - /* Wait until bdev->bd_disk is definitely gone */ - if (work_pending(&mddev->del_work)) - flush_workqueue(md_misc_wq); - return -EBUSY; - } - BUG_ON(mddev != bdev->bd_disk->private_data); - - if ((err = mutex_lock_interruptible(&mddev->open_mutex))) + err = mutex_lock_interruptible(&mddev->open_mutex); + if (err) goto out; - if (test_bit(MD_CLOSING, &mddev->flags)) { - mutex_unlock(&mddev->open_mutex); - err = -ENODEV; - goto out; - } + err = -ENODEV; + if (test_bit(MD_CLOSING, &mddev->flags)) + goto out_unlock; - err = 0; atomic_inc(&mddev->openers); mutex_unlock(&mddev->open_mutex); bdev_check_media_change(bdev); - out: - if (err) - mddev_put(mddev); + return 0; + +out_unlock: + mutex_unlock(&mddev->open_mutex); +out: + mddev_put(mddev); return err; }
Now that devices are on the all_mddevs list until the gendisk is freed, there can't be any duplicates. Remove the global list lookup and just grab a reference. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/md/md.c | 42 +++++++++++++++--------------------------- 1 file changed, 15 insertions(+), 27 deletions(-)