Commit a74968f8 authored by Roland Dreier's avatar Roland Dreier

[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: default avatarRoland Dreier <rolandd@cisco.com>
parent 1993d683
......@@ -64,18 +64,39 @@ enum {
IB_UMAD_MINOR_BASE = 0
};
/*
* Our lifetime rules for these structs are the following: each time a
* device special file is opened, we look up the corresponding struct
* ib_umad_port by minor in the umad_port[] table while holding the
* port_lock. If this lookup succeeds, we take a reference on the
* ib_umad_port's struct ib_umad_device while still holding the
* port_lock; if the lookup fails, we fail the open(). We drop these
* references in the corresponding close().
*
* In addition to references coming from open character devices, there
* is one more reference to each ib_umad_device representing the
* module's reference taken when allocating the ib_umad_device in
* ib_umad_add_one().
*
* When destroying an ib_umad_device, we clear all of its
* ib_umad_ports from umad_port[] while holding port_lock before
* dropping the module's reference to the ib_umad_device. This is
* always safe because any open() calls will either succeed and obtain
* a reference before we clear the umad_port[] entries, or fail after
* we clear the umad_port[] entries.
*/
struct ib_umad_port {
int devnum;
struct cdev dev;
struct class_device class_dev;
struct cdev *dev;
struct class_device *class_dev;
int sm_devnum;
struct cdev sm_dev;
struct class_device sm_class_dev;
struct cdev *sm_dev;
struct class_device *sm_class_dev;
struct semaphore sm_sem;
struct ib_device *ib_dev;
struct ib_umad_device *umad_dev;
int dev_num;
u8 port_num;
};
......@@ -102,13 +123,25 @@ struct ib_umad_packet {
struct ib_user_mad mad;
};
static struct class *umad_class;
static const dev_t base_dev = MKDEV(IB_UMAD_MAJOR, IB_UMAD_MINOR_BASE);
static spinlock_t map_lock;
static DEFINE_SPINLOCK(port_lock);
static struct ib_umad_port *umad_port[IB_UMAD_MAX_PORTS];
static DECLARE_BITMAP(dev_map, IB_UMAD_MAX_PORTS * 2);
static void ib_umad_add_one(struct ib_device *device);
static void ib_umad_remove_one(struct ib_device *device);
static void ib_umad_release_dev(struct kref *ref)
{
struct ib_umad_device *dev =
container_of(ref, struct ib_umad_device, ref);
kfree(dev);
}
static int queue_packet(struct ib_umad_file *file,
struct ib_mad_agent *agent,
struct ib_umad_packet *packet)
......@@ -534,13 +567,23 @@ static long ib_umad_ioctl(struct file *filp, unsigned int cmd,
static int ib_umad_open(struct inode *inode, struct file *filp)
{
struct ib_umad_port *port =
container_of(inode->i_cdev, struct ib_umad_port, dev);
struct ib_umad_port *port;
struct ib_umad_file *file;
spin_lock(&port_lock);
port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE];
if (port)
kref_get(&port->umad_dev->ref);
spin_unlock(&port_lock);
if (!port)
return -ENXIO;
file = kzalloc(sizeof *file, GFP_KERNEL);
if (!file)
if (!file) {
kref_put(&port->umad_dev->ref, ib_umad_release_dev);
return -ENOMEM;
}
spin_lock_init(&file->recv_lock);
init_rwsem(&file->agent_mutex);
......@@ -556,6 +599,7 @@ static int ib_umad_open(struct inode *inode, struct file *filp)
static int ib_umad_close(struct inode *inode, struct file *filp)
{
struct ib_umad_file *file = filp->private_data;
struct ib_umad_device *dev = file->port->umad_dev;
struct ib_umad_packet *packet, *tmp;
int i;
......@@ -570,6 +614,8 @@ static int ib_umad_close(struct inode *inode, struct file *filp)
kfree(file);
kref_put(&dev->ref, ib_umad_release_dev);
return 0;
}
......@@ -586,30 +632,46 @@ static struct file_operations umad_fops = {
static int ib_umad_sm_open(struct inode *inode, struct file *filp)
{
struct ib_umad_port *port =
container_of(inode->i_cdev, struct ib_umad_port, sm_dev);
struct ib_umad_port *port;
struct ib_port_modify props = {
.set_port_cap_mask = IB_PORT_SM
};
int ret;
spin_lock(&port_lock);
port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE - IB_UMAD_MAX_PORTS];
if (port)
kref_get(&port->umad_dev->ref);
spin_unlock(&port_lock);
if (!port)
return -ENXIO;
if (filp->f_flags & O_NONBLOCK) {
if (down_trylock(&port->sm_sem))
return -EAGAIN;
if (down_trylock(&port->sm_sem)) {
ret = -EAGAIN;
goto fail;
}
} else {
if (down_interruptible(&port->sm_sem))
return -ERESTARTSYS;
if (down_interruptible(&port->sm_sem)) {
ret = -ERESTARTSYS;
goto fail;
}
}
ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
if (ret) {
up(&port->sm_sem);
return ret;
goto fail;
}
filp->private_data = port;
return 0;
fail:
kref_put(&port->umad_dev->ref, ib_umad_release_dev);
return ret;
}
static int ib_umad_sm_close(struct inode *inode, struct file *filp)
......@@ -623,6 +685,8 @@ static int ib_umad_sm_close(struct inode *inode, struct file *filp)
ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
up(&port->sm_sem);
kref_put(&port->umad_dev->ref, ib_umad_release_dev);
return ret;
}
......@@ -642,6 +706,9 @@ static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
{
struct ib_umad_port *port = class_get_devdata(class_dev);
if (!port)
return -ENODEV;
return sprintf(buf, "%s\n", port->ib_dev->name);
}
static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
......@@ -650,38 +717,13 @@ static ssize_t show_port(struct class_device *class_dev, char *buf)
{
struct ib_umad_port *port = class_get_devdata(class_dev);
if (!port)
return -ENODEV;
return sprintf(buf, "%d\n", port->port_num);
}
static CLASS_DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
static void ib_umad_release_dev(struct kref *ref)
{
struct ib_umad_device *dev =
container_of(ref, struct ib_umad_device, ref);
kfree(dev);
}
static void ib_umad_release_port(struct class_device *class_dev)
{
struct ib_umad_port *port = class_get_devdata(class_dev);
if (class_dev == &port->class_dev) {
cdev_del(&port->dev);
clear_bit(port->devnum, dev_map);
} else {
cdev_del(&port->sm_dev);
clear_bit(port->sm_devnum, dev_map);
}
kref_put(&port->umad_dev->ref, ib_umad_release_dev);
}
static struct class umad_class = {
.name = "infiniband_mad",
.release = ib_umad_release_port
};
static ssize_t show_abi_version(struct class *class, char *buf)
{
return sprintf(buf, "%d\n", IB_USER_MAD_ABI_VERSION);
......@@ -691,89 +733,102 @@ static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
static int ib_umad_init_port(struct ib_device *device, int port_num,
struct ib_umad_port *port)
{
spin_lock(&map_lock);
port->devnum = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
if (port->devnum >= IB_UMAD_MAX_PORTS) {
spin_unlock(&map_lock);
spin_lock(&port_lock);
port->dev_num = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
if (port->dev_num >= IB_UMAD_MAX_PORTS) {
spin_unlock(&port_lock);
return -1;
}
port->sm_devnum = find_next_zero_bit(dev_map, IB_UMAD_MAX_PORTS * 2, IB_UMAD_MAX_PORTS);
if (port->sm_devnum >= IB_UMAD_MAX_PORTS * 2) {
spin_unlock(&map_lock);
return -1;
}
set_bit(port->devnum, dev_map);
set_bit(port->sm_devnum, dev_map);
spin_unlock(&map_lock);
set_bit(port->dev_num, dev_map);
spin_unlock(&port_lock);
port->ib_dev = device;
port->port_num = port_num;
init_MUTEX(&port->sm_sem);
cdev_init(&port->dev, &umad_fops);
port->dev.owner = THIS_MODULE;
kobject_set_name(&port->dev.kobj, "umad%d", port->devnum);
if (cdev_add(&port->dev, base_dev + port->devnum, 1))
port->dev = cdev_alloc();
if (!port->dev)
return -1;
port->class_dev.class = &umad_class;
port->class_dev.dev = device->dma_device;
port->class_dev.devt = port->dev.dev;
snprintf(port->class_dev.class_id, BUS_ID_SIZE, "umad%d", port->devnum);
if (class_device_register(&port->class_dev))
port->dev->owner = THIS_MODULE;
port->dev->ops = &umad_fops;
kobject_set_name(&port->dev->kobj, "umad%d", port->dev_num);
if (cdev_add(port->dev, base_dev + port->dev_num, 1))
goto err_cdev;
class_set_devdata(&port->class_dev, port);
kref_get(&port->umad_dev->ref);
port->class_dev = class_device_create(umad_class, port->dev->dev,
device->dma_device,
"umad%d", port->dev_num);
if (IS_ERR(port->class_dev))
goto err_cdev;
if (class_device_create_file(&port->class_dev, &class_device_attr_ibdev))
if (class_device_create_file(port->class_dev, &class_device_attr_ibdev))
goto err_class;
if (class_device_create_file(&port->class_dev, &class_device_attr_port))
if (class_device_create_file(port->class_dev, &class_device_attr_port))
goto err_class;
cdev_init(&port->sm_dev, &umad_sm_fops);
port->sm_dev.owner = THIS_MODULE;
kobject_set_name(&port->dev.kobj, "issm%d", port->sm_devnum - IB_UMAD_MAX_PORTS);
if (cdev_add(&port->sm_dev, base_dev + port->sm_devnum, 1))
return -1;
port->sm_class_dev.class = &umad_class;
port->sm_class_dev.dev = device->dma_device;
port->sm_class_dev.devt = port->sm_dev.dev;
snprintf(port->sm_class_dev.class_id, BUS_ID_SIZE, "issm%d", port->sm_devnum - IB_UMAD_MAX_PORTS);
port->sm_dev = cdev_alloc();
if (!port->sm_dev)
goto err_class;
port->sm_dev->owner = THIS_MODULE;
port->sm_dev->ops = &umad_sm_fops;
kobject_set_name(&port->dev->kobj, "issm%d", port->dev_num);
if (cdev_add(port->sm_dev, base_dev + port->dev_num + IB_UMAD_MAX_PORTS, 1))
goto err_sm_cdev;
if (class_device_register(&port->sm_class_dev))
port->sm_class_dev = class_device_create(umad_class, port->sm_dev->dev,
device->dma_device,
"issm%d", port->dev_num);
if (IS_ERR(port->sm_class_dev))
goto err_sm_cdev;
class_set_devdata(&port->sm_class_dev, port);
kref_get(&port->umad_dev->ref);
class_set_devdata(port->class_dev, port);
class_set_devdata(port->sm_class_dev, port);
if (class_device_create_file(&port->sm_class_dev, &class_device_attr_ibdev))
if (class_device_create_file(port->sm_class_dev, &class_device_attr_ibdev))
goto err_sm_class;
if (class_device_create_file(&port->sm_class_dev, &class_device_attr_port))
if (class_device_create_file(port->sm_class_dev, &class_device_attr_port))
goto err_sm_class;
spin_lock(&port_lock);
umad_port[port->dev_num] = port;
spin_unlock(&port_lock);
return 0;
err_sm_class:
class_device_unregister(&port->sm_class_dev);
class_device_destroy(umad_class, port->sm_dev->dev);
err_sm_cdev:
cdev_del(&port->sm_dev);
cdev_del(port->sm_dev);
err_class:
class_device_unregister(&port->class_dev);
class_device_destroy(umad_class, port->dev->dev);
err_cdev:
cdev_del(&port->dev);
clear_bit(port->devnum, dev_map);
cdev_del(port->dev);
clear_bit(port->dev_num, dev_map);
return -1;
}
static void ib_umad_kill_port(struct ib_umad_port *port)
{
class_set_devdata(port->class_dev, NULL);
class_set_devdata(port->sm_class_dev, NULL);
class_device_destroy(umad_class, port->dev->dev);
class_device_destroy(umad_class, port->sm_dev->dev);
cdev_del(port->dev);
cdev_del(port->sm_dev);
spin_lock(&port_lock);
umad_port[port->dev_num] = NULL;
spin_unlock(&port_lock);
clear_bit(port->dev_num, dev_map);
}
static void ib_umad_add_one(struct ib_device *device)
{
struct ib_umad_device *umad_dev;
......@@ -809,10 +864,8 @@ static void ib_umad_add_one(struct ib_device *device)
return;
err:
while (--i >= s) {
class_device_unregister(&umad_dev->port[i - s].class_dev);
class_device_unregister(&umad_dev->port[i - s].sm_class_dev);
}
while (--i >= s)
ib_umad_kill_port(&umad_dev->port[i]);
kref_put(&umad_dev->ref, ib_umad_release_dev);
}
......@@ -825,10 +878,8 @@ static void ib_umad_remove_one(struct ib_device *device)
if (!umad_dev)
return;
for (i = 0; i <= umad_dev->end_port - umad_dev->start_port; ++i) {
class_device_unregister(&umad_dev->port[i].class_dev);
class_device_unregister(&umad_dev->port[i].sm_class_dev);
}
for (i = 0; i <= umad_dev->end_port - umad_dev->start_port; ++i)
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)
{
int ret;
spin_lock_init(&map_lock);
ret = register_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2,
"infiniband_mad");
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 @@ static int __init ib_umad_init(void)
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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