[IB] umad: Fix device lifetime problems
Move ib_umad module to using cdev_alloc() and class_device_create() so that we can handle device lifetime properly. Now we can make sure we keep all of our data structures around until the last way to reach them is gone. Signed-off-by: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Roland Dreier
Родитель
1993d683f3
Коммит
a74968f8c3
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@ -64,18 +64,39 @@ enum {
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IB_UMAD_MINOR_BASE = 0
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};
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struct ib_umad_port {
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int devnum;
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struct cdev dev;
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struct class_device class_dev;
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/*
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* Our lifetime rules for these structs are the following: each time a
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* device special file is opened, we look up the corresponding struct
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* ib_umad_port by minor in the umad_port[] table while holding the
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* port_lock. If this lookup succeeds, we take a reference on the
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* ib_umad_port's struct ib_umad_device while still holding the
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* port_lock; if the lookup fails, we fail the open(). We drop these
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* references in the corresponding close().
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*
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* In addition to references coming from open character devices, there
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* is one more reference to each ib_umad_device representing the
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* module's reference taken when allocating the ib_umad_device in
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* ib_umad_add_one().
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*
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* When destroying an ib_umad_device, we clear all of its
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* ib_umad_ports from umad_port[] while holding port_lock before
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* dropping the module's reference to the ib_umad_device. This is
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* always safe because any open() calls will either succeed and obtain
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* a reference before we clear the umad_port[] entries, or fail after
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* we clear the umad_port[] entries.
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*/
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int sm_devnum;
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struct cdev sm_dev;
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struct class_device sm_class_dev;
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struct ib_umad_port {
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struct cdev *dev;
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struct class_device *class_dev;
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struct cdev *sm_dev;
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struct class_device *sm_class_dev;
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struct semaphore sm_sem;
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struct ib_device *ib_dev;
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struct ib_umad_device *umad_dev;
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int dev_num;
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u8 port_num;
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};
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@ -102,13 +123,25 @@ struct ib_umad_packet {
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struct ib_user_mad mad;
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};
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static struct class *umad_class;
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static const dev_t base_dev = MKDEV(IB_UMAD_MAJOR, IB_UMAD_MINOR_BASE);
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static spinlock_t map_lock;
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static DEFINE_SPINLOCK(port_lock);
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static struct ib_umad_port *umad_port[IB_UMAD_MAX_PORTS];
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static DECLARE_BITMAP(dev_map, IB_UMAD_MAX_PORTS * 2);
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static void ib_umad_add_one(struct ib_device *device);
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static void ib_umad_remove_one(struct ib_device *device);
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static void ib_umad_release_dev(struct kref *ref)
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{
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struct ib_umad_device *dev =
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container_of(ref, struct ib_umad_device, ref);
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kfree(dev);
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}
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static int queue_packet(struct ib_umad_file *file,
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struct ib_mad_agent *agent,
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struct ib_umad_packet *packet)
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@ -534,13 +567,23 @@ static long ib_umad_ioctl(struct file *filp, unsigned int cmd,
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static int ib_umad_open(struct inode *inode, struct file *filp)
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{
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struct ib_umad_port *port =
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container_of(inode->i_cdev, struct ib_umad_port, dev);
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struct ib_umad_port *port;
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struct ib_umad_file *file;
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spin_lock(&port_lock);
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port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE];
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if (port)
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kref_get(&port->umad_dev->ref);
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spin_unlock(&port_lock);
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if (!port)
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return -ENXIO;
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file = kzalloc(sizeof *file, GFP_KERNEL);
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if (!file)
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if (!file) {
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kref_put(&port->umad_dev->ref, ib_umad_release_dev);
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return -ENOMEM;
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}
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spin_lock_init(&file->recv_lock);
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init_rwsem(&file->agent_mutex);
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@ -556,6 +599,7 @@ static int ib_umad_open(struct inode *inode, struct file *filp)
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static int ib_umad_close(struct inode *inode, struct file *filp)
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{
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struct ib_umad_file *file = filp->private_data;
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struct ib_umad_device *dev = file->port->umad_dev;
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struct ib_umad_packet *packet, *tmp;
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int i;
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@ -570,6 +614,8 @@ static int ib_umad_close(struct inode *inode, struct file *filp)
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kfree(file);
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kref_put(&dev->ref, ib_umad_release_dev);
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return 0;
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}
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@ -586,30 +632,46 @@ static struct file_operations umad_fops = {
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static int ib_umad_sm_open(struct inode *inode, struct file *filp)
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{
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struct ib_umad_port *port =
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container_of(inode->i_cdev, struct ib_umad_port, sm_dev);
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struct ib_umad_port *port;
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struct ib_port_modify props = {
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.set_port_cap_mask = IB_PORT_SM
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};
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int ret;
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spin_lock(&port_lock);
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port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE - IB_UMAD_MAX_PORTS];
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if (port)
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kref_get(&port->umad_dev->ref);
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spin_unlock(&port_lock);
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if (!port)
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return -ENXIO;
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if (filp->f_flags & O_NONBLOCK) {
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if (down_trylock(&port->sm_sem))
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return -EAGAIN;
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if (down_trylock(&port->sm_sem)) {
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ret = -EAGAIN;
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goto fail;
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}
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} else {
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if (down_interruptible(&port->sm_sem))
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return -ERESTARTSYS;
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if (down_interruptible(&port->sm_sem)) {
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ret = -ERESTARTSYS;
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goto fail;
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}
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}
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ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
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if (ret) {
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up(&port->sm_sem);
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return ret;
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goto fail;
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}
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filp->private_data = port;
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return 0;
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fail:
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kref_put(&port->umad_dev->ref, ib_umad_release_dev);
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return ret;
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}
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static int ib_umad_sm_close(struct inode *inode, struct file *filp)
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@ -623,6 +685,8 @@ static int ib_umad_sm_close(struct inode *inode, struct file *filp)
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ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
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up(&port->sm_sem);
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kref_put(&port->umad_dev->ref, ib_umad_release_dev);
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return ret;
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}
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@ -642,6 +706,9 @@ static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
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{
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struct ib_umad_port *port = class_get_devdata(class_dev);
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if (!port)
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return -ENODEV;
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return sprintf(buf, "%s\n", port->ib_dev->name);
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}
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static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
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@ -650,38 +717,13 @@ static ssize_t show_port(struct class_device *class_dev, char *buf)
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{
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struct ib_umad_port *port = class_get_devdata(class_dev);
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if (!port)
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return -ENODEV;
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return sprintf(buf, "%d\n", port->port_num);
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}
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static CLASS_DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
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static void ib_umad_release_dev(struct kref *ref)
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{
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struct ib_umad_device *dev =
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container_of(ref, struct ib_umad_device, ref);
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kfree(dev);
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}
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static void ib_umad_release_port(struct class_device *class_dev)
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{
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struct ib_umad_port *port = class_get_devdata(class_dev);
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if (class_dev == &port->class_dev) {
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cdev_del(&port->dev);
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clear_bit(port->devnum, dev_map);
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} else {
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cdev_del(&port->sm_dev);
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clear_bit(port->sm_devnum, dev_map);
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}
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kref_put(&port->umad_dev->ref, ib_umad_release_dev);
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}
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static struct class umad_class = {
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.name = "infiniband_mad",
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.release = ib_umad_release_port
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};
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static ssize_t show_abi_version(struct class *class, char *buf)
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{
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return sprintf(buf, "%d\n", IB_USER_MAD_ABI_VERSION);
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@ -691,89 +733,102 @@ static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
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static int ib_umad_init_port(struct ib_device *device, int port_num,
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struct ib_umad_port *port)
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{
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spin_lock(&map_lock);
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port->devnum = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
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if (port->devnum >= IB_UMAD_MAX_PORTS) {
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spin_unlock(&map_lock);
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spin_lock(&port_lock);
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port->dev_num = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
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if (port->dev_num >= IB_UMAD_MAX_PORTS) {
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spin_unlock(&port_lock);
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return -1;
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}
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port->sm_devnum = find_next_zero_bit(dev_map, IB_UMAD_MAX_PORTS * 2, IB_UMAD_MAX_PORTS);
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if (port->sm_devnum >= IB_UMAD_MAX_PORTS * 2) {
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spin_unlock(&map_lock);
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return -1;
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}
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set_bit(port->devnum, dev_map);
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set_bit(port->sm_devnum, dev_map);
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spin_unlock(&map_lock);
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set_bit(port->dev_num, dev_map);
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spin_unlock(&port_lock);
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port->ib_dev = device;
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port->port_num = port_num;
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init_MUTEX(&port->sm_sem);
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cdev_init(&port->dev, &umad_fops);
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port->dev.owner = THIS_MODULE;
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kobject_set_name(&port->dev.kobj, "umad%d", port->devnum);
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if (cdev_add(&port->dev, base_dev + port->devnum, 1))
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port->dev = cdev_alloc();
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if (!port->dev)
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return -1;
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port->class_dev.class = &umad_class;
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port->class_dev.dev = device->dma_device;
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port->class_dev.devt = port->dev.dev;
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snprintf(port->class_dev.class_id, BUS_ID_SIZE, "umad%d", port->devnum);
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if (class_device_register(&port->class_dev))
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port->dev->owner = THIS_MODULE;
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port->dev->ops = &umad_fops;
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kobject_set_name(&port->dev->kobj, "umad%d", port->dev_num);
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if (cdev_add(port->dev, base_dev + port->dev_num, 1))
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goto err_cdev;
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class_set_devdata(&port->class_dev, port);
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kref_get(&port->umad_dev->ref);
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port->class_dev = class_device_create(umad_class, port->dev->dev,
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device->dma_device,
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"umad%d", port->dev_num);
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if (IS_ERR(port->class_dev))
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goto err_cdev;
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if (class_device_create_file(&port->class_dev, &class_device_attr_ibdev))
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if (class_device_create_file(port->class_dev, &class_device_attr_ibdev))
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goto err_class;
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if (class_device_create_file(&port->class_dev, &class_device_attr_port))
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if (class_device_create_file(port->class_dev, &class_device_attr_port))
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goto err_class;
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cdev_init(&port->sm_dev, &umad_sm_fops);
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port->sm_dev.owner = THIS_MODULE;
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kobject_set_name(&port->dev.kobj, "issm%d", port->sm_devnum - IB_UMAD_MAX_PORTS);
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if (cdev_add(&port->sm_dev, base_dev + port->sm_devnum, 1))
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return -1;
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port->sm_class_dev.class = &umad_class;
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port->sm_class_dev.dev = device->dma_device;
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port->sm_class_dev.devt = port->sm_dev.dev;
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snprintf(port->sm_class_dev.class_id, BUS_ID_SIZE, "issm%d", port->sm_devnum - IB_UMAD_MAX_PORTS);
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if (class_device_register(&port->sm_class_dev))
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port->sm_dev = cdev_alloc();
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if (!port->sm_dev)
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goto err_class;
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port->sm_dev->owner = THIS_MODULE;
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port->sm_dev->ops = &umad_sm_fops;
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kobject_set_name(&port->dev->kobj, "issm%d", port->dev_num);
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if (cdev_add(port->sm_dev, base_dev + port->dev_num + IB_UMAD_MAX_PORTS, 1))
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goto err_sm_cdev;
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class_set_devdata(&port->sm_class_dev, port);
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kref_get(&port->umad_dev->ref);
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port->sm_class_dev = class_device_create(umad_class, port->sm_dev->dev,
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device->dma_device,
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"issm%d", port->dev_num);
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if (IS_ERR(port->sm_class_dev))
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goto err_sm_cdev;
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if (class_device_create_file(&port->sm_class_dev, &class_device_attr_ibdev))
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class_set_devdata(port->class_dev, port);
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class_set_devdata(port->sm_class_dev, port);
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if (class_device_create_file(port->sm_class_dev, &class_device_attr_ibdev))
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goto err_sm_class;
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if (class_device_create_file(&port->sm_class_dev, &class_device_attr_port))
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if (class_device_create_file(port->sm_class_dev, &class_device_attr_port))
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goto err_sm_class;
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spin_lock(&port_lock);
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umad_port[port->dev_num] = port;
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spin_unlock(&port_lock);
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return 0;
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err_sm_class:
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class_device_unregister(&port->sm_class_dev);
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class_device_destroy(umad_class, port->sm_dev->dev);
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err_sm_cdev:
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cdev_del(&port->sm_dev);
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cdev_del(port->sm_dev);
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err_class:
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class_device_unregister(&port->class_dev);
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class_device_destroy(umad_class, port->dev->dev);
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err_cdev:
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cdev_del(&port->dev);
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clear_bit(port->devnum, dev_map);
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cdev_del(port->dev);
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clear_bit(port->dev_num, dev_map);
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|
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return -1;
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}
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static void ib_umad_kill_port(struct ib_umad_port *port)
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{
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class_set_devdata(port->class_dev, NULL);
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class_set_devdata(port->sm_class_dev, NULL);
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class_device_destroy(umad_class, port->dev->dev);
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class_device_destroy(umad_class, port->sm_dev->dev);
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|
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cdev_del(port->dev);
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cdev_del(port->sm_dev);
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|
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spin_lock(&port_lock);
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umad_port[port->dev_num] = NULL;
|
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spin_unlock(&port_lock);
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|
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clear_bit(port->dev_num, dev_map);
|
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}
|
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|
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static void ib_umad_add_one(struct ib_device *device)
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{
|
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struct ib_umad_device *umad_dev;
|
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|
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@ -809,10 +864,8 @@ static void ib_umad_add_one(struct ib_device *device)
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return;
|
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|
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err:
|
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while (--i >= s) {
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class_device_unregister(&umad_dev->port[i - s].class_dev);
|
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class_device_unregister(&umad_dev->port[i - s].sm_class_dev);
|
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}
|
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while (--i >= s)
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ib_umad_kill_port(&umad_dev->port[i]);
|
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|
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kref_put(&umad_dev->ref, ib_umad_release_dev);
|
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}
|
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|
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@ -825,10 +878,8 @@ static void ib_umad_remove_one(struct ib_device *device)
|
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if (!umad_dev)
|
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return;
|
||||
|
||||
for (i = 0; i <= umad_dev->end_port - umad_dev->start_port; ++i) {
|
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class_device_unregister(&umad_dev->port[i].class_dev);
|
||||
class_device_unregister(&umad_dev->port[i].sm_class_dev);
|
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}
|
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for (i = 0; i <= umad_dev->end_port - umad_dev->start_port; ++i)
|
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ib_umad_kill_port(&umad_dev->port[i]);
|
||||
|
||||
kref_put(&umad_dev->ref, ib_umad_release_dev);
|
||||
}
|
||||
|
|
@ -837,8 +888,6 @@ static int __init ib_umad_init(void)
|
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{
|
||||
int ret;
|
||||
|
||||
spin_lock_init(&map_lock);
|
||||
|
||||
ret = register_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2,
|
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"infiniband_mad");
|
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if (ret) {
|
||||
|
|
@ -846,13 +895,14 @@ static int __init ib_umad_init(void)
|
|||
goto out;
|
||||
}
|
||||
|
||||
ret = class_register(&umad_class);
|
||||
if (ret) {
|
||||
umad_class = class_create(THIS_MODULE, "infiniband_mad");
|
||||
if (IS_ERR(umad_class)) {
|
||||
ret = PTR_ERR(umad_class);
|
||||
printk(KERN_ERR "user_mad: couldn't create class infiniband_mad\n");
|
||||
goto out_chrdev;
|
||||
}
|
||||
|
||||
ret = class_create_file(&umad_class, &class_attr_abi_version);
|
||||
ret = class_create_file(umad_class, &class_attr_abi_version);
|
||||
if (ret) {
|
||||
printk(KERN_ERR "user_mad: couldn't create abi_version attribute\n");
|
||||
goto out_class;
|
||||
|
|
@ -867,7 +917,7 @@ static int __init ib_umad_init(void)
|
|||
return 0;
|
||||
|
||||
out_class:
|
||||
class_unregister(&umad_class);
|
||||
class_destroy(umad_class);
|
||||
|
||||
out_chrdev:
|
||||
unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
|
||||
|
|
@ -879,7 +929,7 @@ out:
|
|||
static void __exit ib_umad_cleanup(void)
|
||||
{
|
||||
ib_unregister_client(&umad_client);
|
||||
class_unregister(&umad_class);
|
||||
class_destroy(umad_class);
|
||||
unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
|
||||
}
|
||||
|
||||
|
|
|
|||
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Ссылка в новой задаче