diff options
| -rw-r--r-- | drivers/md/md.c | 18 | ||||
| -rw-r--r-- | drivers/md/md.h | 10 |
2 files changed, 20 insertions, 8 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 5b98bea4ff9..5614500092e 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -359,6 +359,7 @@ static mddev_t * mddev_find(dev_t unit) else new->md_minor = MINOR(unit) >> MdpMinorShift; + mutex_init(&new->open_mutex); mutex_init(&new->reconfig_mutex); INIT_LIST_HEAD(&new->disks); INIT_LIST_HEAD(&new->all_mddevs); @@ -4304,12 +4305,11 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open) struct gendisk *disk = mddev->gendisk; mdk_rdev_t *rdev; + mutex_lock(&mddev->open_mutex); if (atomic_read(&mddev->openers) > is_open) { printk("md: %s still in use.\n",mdname(mddev)); - return -EBUSY; - } - - if (mddev->pers) { + err = -EBUSY; + } else if (mddev->pers) { if (mddev->sync_thread) { set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); @@ -4367,7 +4367,10 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open) set_disk_ro(disk, 1); clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); } - +out: + mutex_unlock(&mddev->open_mutex); + if (err) + return err; /* * Free resources if final stop */ @@ -4433,7 +4436,6 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open) blk_integrity_unregister(disk); md_new_event(mddev); sysfs_notify_dirent(mddev->sysfs_state); -out: return err; } @@ -5518,12 +5520,12 @@ static int md_open(struct block_device *bdev, fmode_t mode) } BUG_ON(mddev != bdev->bd_disk->private_data); - if ((err = mutex_lock_interruptible_nested(&mddev->reconfig_mutex, 1))) + if ((err = mutex_lock_interruptible(&mddev->open_mutex))) goto out; err = 0; atomic_inc(&mddev->openers); - mddev_unlock(mddev); + mutex_unlock(&mddev->open_mutex); check_disk_change(bdev); out: diff --git a/drivers/md/md.h b/drivers/md/md.h index 78f03168baf..f8fc188bc76 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -223,6 +223,16 @@ struct mddev_s * so we don't loop trying */ int in_sync; /* know to not need resync */ + /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so + * that we are never stopping an array while it is open. + * 'reconfig_mutex' protects all other reconfiguration. + * These locks are separate due to conflicting interactions + * with bdev->bd_mutex. + * Lock ordering is: + * reconfig_mutex -> bd_mutex : e.g. do_md_run -> revalidate_disk + * bd_mutex -> open_mutex: e.g. __blkdev_get -> md_open + */ + struct mutex open_mutex; struct mutex reconfig_mutex; atomic_t active; /* general refcount */ atomic_t openers; /* number of active opens */ |