diff options
| author | Keith Busch | 2015-10-02 01:14:10 +0200 |
|---|---|---|
| committer | Jens Axboe | 2015-10-09 18:40:36 +0200 |
| commit | 188c3568f814fea965947ed24739987ba9c5a87e (patch) | |
| tree | 553e44c9332afce5890e573785ce9887cd01a7ac /drivers/block/nvme-core.c | |
| parent | Merge branch 'for-4.4/core' into for-4.4/drivers (diff) | |
| download | kernel-qcow2-linux-188c3568f814fea965947ed24739987ba9c5a87e.tar.gz kernel-qcow2-linux-188c3568f814fea965947ed24739987ba9c5a87e.tar.xz kernel-qcow2-linux-188c3568f814fea965947ed24739987ba9c5a87e.zip | |
NVMe: Reference count open namespaces
Dynamic namespace attachment means the namespace may be removed at any
time, so the namespace reference count can not be tied to the device
reference count. This fixes a NULL dereference if an opened namespace
is detached from a controller.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block/nvme-core.c')
| -rw-r--r-- | drivers/block/nvme-core.c | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index 6f04771f1019..b02ae3d759d7 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -1943,6 +1943,18 @@ static int nvme_compat_ioctl(struct block_device *bdev, fmode_t mode, #define nvme_compat_ioctl NULL #endif +static void nvme_free_ns(struct kref *kref) +{ + struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref); + + spin_lock(&dev_list_lock); + ns->disk->private_data = NULL; + spin_unlock(&dev_list_lock); + + put_disk(ns->disk); + kfree(ns); +} + static int nvme_open(struct block_device *bdev, fmode_t mode) { int ret = 0; @@ -1952,21 +1964,25 @@ static int nvme_open(struct block_device *bdev, fmode_t mode) ns = bdev->bd_disk->private_data; if (!ns) ret = -ENXIO; - else if (!kref_get_unless_zero(&ns->dev->kref)) + else if (!kref_get_unless_zero(&ns->kref)) ret = -ENXIO; + else if (!kref_get_unless_zero(&ns->dev->kref)) { + kref_put(&ns->kref, nvme_free_ns); + ret = -ENXIO; + } spin_unlock(&dev_list_lock); return ret; } static void nvme_free_dev(struct kref *kref); - static void nvme_release(struct gendisk *disk, fmode_t mode) { struct nvme_ns *ns = disk->private_data; struct nvme_dev *dev = ns->dev; kref_put(&dev->kref, nvme_free_dev); + kref_put(&ns->kref, nvme_free_ns); } static int nvme_getgeo(struct block_device *bd, struct hd_geometry *geo) @@ -2126,6 +2142,7 @@ static void nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid) if (!disk) goto out_free_queue; + kref_init(&ns->kref); ns->ns_id = nsid; ns->disk = disk; ns->lba_shift = 9; /* set to a default value for 512 until disk is validated */ @@ -2360,13 +2377,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev) static void nvme_free_namespace(struct nvme_ns *ns) { list_del(&ns->list); - - spin_lock(&dev_list_lock); - ns->disk->private_data = NULL; - spin_unlock(&dev_list_lock); - - put_disk(ns->disk); - kfree(ns); + kref_put(&ns->kref, nvme_free_ns); } static int ns_cmp(void *priv, struct list_head *a, struct list_head *b) |