diff options
| -rw-r--r-- | drivers/md/md.c | 61 | ||||
| -rw-r--r-- | fs/block_dev.c | 14 | ||||
| -rw-r--r-- | include/linux/raid/md_k.h | 4 |
3 files changed, 67 insertions, 12 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 970a8c42ba92..38697283aaf4 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -214,16 +214,33 @@ static inline mddev_t *mddev_get(mddev_t *mddev) return mddev; } +static void mddev_delayed_delete(struct work_struct *ws) +{ + mddev_t *mddev = container_of(ws, mddev_t, del_work); + kobject_del(&mddev->kobj); + kobject_put(&mddev->kobj); +} + static void mddev_put(mddev_t *mddev) { if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock)) return; - if (!mddev->raid_disks && list_empty(&mddev->disks)) { + if (!mddev->raid_disks && list_empty(&mddev->disks) && + !mddev->hold_active) { list_del(&mddev->all_mddevs); - spin_unlock(&all_mddevs_lock); - kobject_put(&mddev->kobj); - } else - spin_unlock(&all_mddevs_lock); + if (mddev->gendisk) { + /* we did a probe so need to clean up. + * Call schedule_work inside the spinlock + * so that flush_scheduled_work() after + * mddev_find will succeed in waiting for the + * work to be done. + */ + INIT_WORK(&mddev->del_work, mddev_delayed_delete); + schedule_work(&mddev->del_work); + } else + kfree(mddev); + } + spin_unlock(&all_mddevs_lock); } static mddev_t * mddev_find(dev_t unit) @@ -242,6 +259,7 @@ static mddev_t * mddev_find(dev_t unit) if (new) { list_add(&new->all_mddevs, &all_mddevs); + mddev->hold_active = UNTIL_IOCTL; spin_unlock(&all_mddevs_lock); return new; } @@ -3435,6 +3453,8 @@ md_attr_store(struct kobject *kobj, struct attribute *attr, if (!capable(CAP_SYS_ADMIN)) return -EACCES; rv = mddev_lock(mddev); + if (mddev->hold_active == UNTIL_IOCTL) + mddev->hold_active = 0; if (!rv) { rv = entry->store(mddev, page, length); mddev_unlock(mddev); @@ -3484,6 +3504,11 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data) if (!mddev) return NULL; + /* wait for any previous instance if this device + * to be completed removed (mddev_delayed_delete). + */ + flush_scheduled_work(); + mutex_lock(&disks_mutex); if (mddev->gendisk) { mutex_unlock(&disks_mutex); @@ -3520,7 +3545,7 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data) disk->private_data = mddev; disk->queue = mddev->queue; /* Allow extended partitions. This makes the - * 'mdp' device redundant, but we can really + * 'mdp' device redundant, but we can't really * remove it now. */ disk->flags |= GENHD_FL_EXT_DEVT; @@ -3536,6 +3561,7 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data) kobject_uevent(&mddev->kobj, KOBJ_ADD); mddev->sysfs_state = sysfs_get_dirent(mddev->kobj.sd, "array_state"); } + mddev_put(mddev); return NULL; } @@ -5054,6 +5080,9 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode, done_unlock: abort_unlock: + if (mddev->hold_active == UNTIL_IOCTL && + err != -EINVAL) + mddev->hold_active = 0; mddev_unlock(mddev); return err; @@ -5070,14 +5099,25 @@ 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. */ - mddev_t *mddev = bdev->bd_disk->private_data; + mddev_t *mddev = mddev_find(bdev->bd_dev); int err; + 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 */ + flush_scheduled_work(); + /* Then retry the open from the top */ + return -ERESTARTSYS; + } + BUG_ON(mddev != bdev->bd_disk->private_data); + if ((err = mutex_lock_interruptible_nested(&mddev->reconfig_mutex, 1))) goto out; err = 0; - mddev_get(mddev); atomic_inc(&mddev->openers); mddev_unlock(mddev); @@ -6436,11 +6476,8 @@ static __exit void md_exit(void) unregister_sysctl_table(raid_table_header); remove_proc_entry("mdstat", NULL); for_each_mddev(mddev, tmp) { - struct gendisk *disk = mddev->gendisk; - if (!disk) - continue; export_array(mddev); - mddev_put(mddev); + mddev->hold_active = 0; } } diff --git a/fs/block_dev.c b/fs/block_dev.c index b957717e25ab..8ebbfdf708c2 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1005,6 +1005,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) } lock_kernel(); + restart: ret = -ENXIO; disk = get_gendisk(bdev->bd_dev, &partno); @@ -1025,6 +1026,19 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) if (disk->fops->open) { ret = disk->fops->open(bdev, mode); + if (ret == -ERESTARTSYS) { + /* Lost a race with 'disk' being + * deleted, try again. + * See md.c + */ + disk_put_part(bdev->bd_part); + bdev->bd_part = NULL; + module_put(disk->fops->owner); + put_disk(disk); + bdev->bd_disk = NULL; + mutex_unlock(&bdev->bd_mutex); + goto restart; + } if (ret) goto out_clear; } diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h index 8f9a54c1fb0e..e3d17c7f954e 100644 --- a/include/linux/raid/md_k.h +++ b/include/linux/raid/md_k.h @@ -137,6 +137,8 @@ struct mddev_s struct gendisk *gendisk; struct kobject kobj; + int hold_active; +#define UNTIL_IOCTL 1 /* Superblock information */ int major_version, @@ -246,6 +248,8 @@ struct mddev_s */ struct sysfs_dirent *sysfs_action; /* handle for 'sync_action' */ + struct work_struct del_work; /* used for delayed sysfs removal */ + spinlock_t write_lock; wait_queue_head_t sb_wait; /* for waiting on superblock updates */ atomic_t pending_writes; /* number of active superblock writes */ |