diff options
author | Christoph Hellwig <hch@lst.de> | 2018-05-29 08:40:23 +0200 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2018-05-29 13:00:25 -0600 |
commit | 5de815a7eedfacf593817ef34634eaa9b75a1482 (patch) | |
tree | 13cca552662936096f7b306dc5dbb7b64dfdd93e /block | |
parent | b7405176b58aa475354f3c0d2ca1c560e9354288 (diff) | |
download | linux-5de815a7eedfacf593817ef34634eaa9b75a1482.tar.gz linux-5de815a7eedfacf593817ef34634eaa9b75a1482.tar.bz2 linux-5de815a7eedfacf593817ef34634eaa9b75a1482.zip |
block: remove parent device reference from struct bsg_class_device
Bsg holding a reference to the parent device may result in a crash if a
bsg file handle is closed after the parent device driver has unloaded.
Holding a reference is not really needed: the parent device must exist
between bsg_register_queue and bsg_unregister_queue. Before the device
goes away the caller does blk_cleanup_queue so that all in-flight
requests to the device are gone and all new requests cannot pass beyond
the queue. The queue itself is a refcounted object and it will stay
alive with a bsg file.
Based on analysis, previous patch and changelog from Anatoliy Glagolev.
Reported-by: Anatoliy Glagolev <glagolig@gmail.com>
Reviewed-by: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r-- | block/bsg-lib.c | 6 | ||||
-rw-r--r-- | block/bsg.c | 39 |
2 files changed, 7 insertions, 38 deletions
diff --git a/block/bsg-lib.c b/block/bsg-lib.c index fc2e5ff2c4b9..9419def8c017 100644 --- a/block/bsg-lib.c +++ b/block/bsg-lib.c @@ -303,11 +303,9 @@ static void bsg_exit_rq(struct request_queue *q, struct request *req) * @name: device to give bsg device * @job_fn: bsg job handler * @dd_job_size: size of LLD data needed for each job - * @release: @dev release function */ struct request_queue *bsg_setup_queue(struct device *dev, const char *name, - bsg_job_fn *job_fn, int dd_job_size, - void (*release)(struct device *)) + bsg_job_fn *job_fn, int dd_job_size) { struct request_queue *q; int ret; @@ -331,7 +329,7 @@ struct request_queue *bsg_setup_queue(struct device *dev, const char *name, blk_queue_softirq_done(q, bsg_softirq_done); blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT); - ret = bsg_register_queue(q, dev, name, &bsg_transport_ops, release); + ret = bsg_register_queue(q, dev, name, &bsg_transport_ops); if (ret) { printk(KERN_ERR "%s: bsg interface failed to " "initialize - register queue\n", dev->kobj.name); diff --git a/block/bsg.c b/block/bsg.c index 30876c5fbf15..132e657e2d91 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -649,18 +649,6 @@ static struct bsg_device *bsg_alloc_device(void) return bd; } -static void bsg_kref_release_function(struct kref *kref) -{ - struct bsg_class_device *bcd = - container_of(kref, struct bsg_class_device, ref); - struct device *parent = bcd->parent; - - if (bcd->release) - bcd->release(bcd->parent); - - put_device(parent); -} - static int bsg_put_device(struct bsg_device *bd) { int ret = 0, do_free; @@ -693,7 +681,6 @@ static int bsg_put_device(struct bsg_device *bd) kfree(bd); out: - kref_put(&q->bsg_dev.ref, bsg_kref_release_function); if (do_free) blk_put_queue(q); return ret; @@ -759,8 +746,6 @@ static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file) */ mutex_lock(&bsg_mutex); bcd = idr_find(&bsg_minor_idr, iminor(inode)); - if (bcd) - kref_get(&bcd->ref); mutex_unlock(&bsg_mutex); if (!bcd) @@ -771,8 +756,6 @@ static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file) return bd; bd = bsg_add_device(inode, bcd->queue, file); - if (IS_ERR(bd)) - kref_put(&bcd->ref, bsg_kref_release_function); return bd; } @@ -912,25 +895,17 @@ void bsg_unregister_queue(struct request_queue *q) sysfs_remove_link(&q->kobj, "bsg"); device_unregister(bcd->class_dev); bcd->class_dev = NULL; - kref_put(&bcd->ref, bsg_kref_release_function); mutex_unlock(&bsg_mutex); } EXPORT_SYMBOL_GPL(bsg_unregister_queue); int bsg_register_queue(struct request_queue *q, struct device *parent, - const char *name, const struct bsg_ops *ops, - void (*release)(struct device *)) + const char *name, const struct bsg_ops *ops) { struct bsg_class_device *bcd; dev_t dev; int ret; struct device *class_dev = NULL; - const char *devname; - - if (name) - devname = name; - else - devname = dev_name(parent); /* * we need a proper transport to send commands, not a stacked device @@ -954,15 +929,12 @@ int bsg_register_queue(struct request_queue *q, struct device *parent, bcd->minor = ret; bcd->queue = q; - bcd->parent = get_device(parent); - bcd->release = release; bcd->ops = ops; - kref_init(&bcd->ref); dev = MKDEV(bsg_major, bcd->minor); - class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname); + class_dev = device_create(bsg_class, parent, dev, NULL, "%s", name); if (IS_ERR(class_dev)) { ret = PTR_ERR(class_dev); - goto put_dev; + goto idr_remove; } bcd->class_dev = class_dev; @@ -977,8 +949,7 @@ int bsg_register_queue(struct request_queue *q, struct device *parent, unregister_class_dev: device_unregister(class_dev); -put_dev: - put_device(parent); +idr_remove: idr_remove(&bsg_minor_idr, bcd->minor); unlock: mutex_unlock(&bsg_mutex); @@ -992,7 +963,7 @@ int bsg_scsi_register_queue(struct request_queue *q, struct device *parent) return -EINVAL; } - return bsg_register_queue(q, parent, NULL, &bsg_scsi_ops, NULL); + return bsg_register_queue(q, parent, dev_name(parent), &bsg_scsi_ops); } EXPORT_SYMBOL_GPL(bsg_scsi_register_queue); |