[IB] uverbs: Fix device lifetime problems

Move ib_uverbs 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 2005-10-28 15:38:26 -07:00
parent a74968f8c3
commit 70a30e16a8
3 changed files with 183 additions and 96 deletions

View file

@ -39,20 +39,38 @@
#ifndef UVERBS_H
#define UVERBS_H
/* Include device.h and fs.h until cdev.h is self-sufficient */
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/kref.h>
#include <linux/idr.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_user_verbs.h>
/*
* Our lifetime rules for these structs are the following:
*
* struct ib_uverbs_device: One reference is held by the module and
* released in ib_uverbs_remove_one(). Another reference is taken by
* ib_uverbs_open() each time the character special file is opened,
* and released in ib_uverbs_release_file() when the file is released.
*
* struct ib_uverbs_file: One reference is held by the VFS and
* released when the file is closed. Another reference is taken when
* an asynchronous event queue file is created and released when the
* event file is closed.
*
* struct ib_uverbs_event_file: One reference is held by the VFS and
* released when the file is closed. For asynchronous event files,
* another reference is held by the corresponding main context file
* and released when that file is closed. For completion event files,
* a reference is taken when a CQ is created that uses the file, and
* released when the CQ is destroyed.
*/
struct ib_uverbs_device {
struct kref ref;
int devnum;
struct cdev dev;
struct class_device class_dev;
struct cdev *dev;
struct class_device *class_dev;
struct ib_device *ib_dev;
int num_comp_vectors;
};
@ -115,6 +133,12 @@ struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
void ib_uverbs_release_event_file(struct kref *ref);
struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd);
void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
struct ib_uverbs_event_file *ev_file,
struct ib_ucq_object *uobj);
void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
struct ib_uevent_object *uobj);
void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context);
void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr);
void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr);

View file

@ -35,6 +35,7 @@
*/
#include <linux/file.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
@ -114,7 +115,7 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
kref_get(&file->async_file->ref);
kref_get(&file->ref);
file->ucontext = ucontext;
file->ucontext = ucontext;
fd_install(resp.async_fd, filp);
@ -761,7 +762,6 @@ ssize_t ib_uverbs_destroy_cq(struct ib_uverbs_file *file,
struct ib_cq *cq;
struct ib_ucq_object *uobj;
struct ib_uverbs_event_file *ev_file;
struct ib_uverbs_event *evt, *tmp;
u64 user_handle;
int ret = -EINVAL;
@ -790,23 +790,7 @@ ssize_t ib_uverbs_destroy_cq(struct ib_uverbs_file *file,
list_del(&uobj->uobject.list);
up(&file->mutex);
if (ev_file) {
spin_lock_irq(&ev_file->lock);
list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
list_del(&evt->list);
kfree(evt);
}
spin_unlock_irq(&ev_file->lock);
kref_put(&ev_file->ref, ib_uverbs_release_event_file);
}
spin_lock_irq(&file->async_file->lock);
list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
list_del(&evt->list);
kfree(evt);
}
spin_unlock_irq(&file->async_file->lock);
ib_uverbs_release_ucq(file, ev_file, uobj);
resp.comp_events_reported = uobj->comp_events_reported;
resp.async_events_reported = uobj->async_events_reported;
@ -1043,7 +1027,6 @@ ssize_t ib_uverbs_destroy_qp(struct ib_uverbs_file *file,
struct ib_uverbs_destroy_qp_resp resp;
struct ib_qp *qp;
struct ib_uevent_object *uobj;
struct ib_uverbs_event *evt, *tmp;
int ret = -EINVAL;
if (copy_from_user(&cmd, buf, sizeof cmd))
@ -1069,12 +1052,7 @@ ssize_t ib_uverbs_destroy_qp(struct ib_uverbs_file *file,
list_del(&uobj->uobject.list);
up(&file->mutex);
spin_lock_irq(&file->async_file->lock);
list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
list_del(&evt->list);
kfree(evt);
}
spin_unlock_irq(&file->async_file->lock);
ib_uverbs_release_uevent(file, uobj);
resp.events_reported = uobj->events_reported;
@ -1741,7 +1719,6 @@ ssize_t ib_uverbs_destroy_srq(struct ib_uverbs_file *file,
struct ib_uverbs_destroy_srq_resp resp;
struct ib_srq *srq;
struct ib_uevent_object *uobj;
struct ib_uverbs_event *evt, *tmp;
int ret = -EINVAL;
if (copy_from_user(&cmd, buf, sizeof cmd))
@ -1767,12 +1744,7 @@ ssize_t ib_uverbs_destroy_srq(struct ib_uverbs_file *file,
list_del(&uobj->uobject.list);
up(&file->mutex);
spin_lock_irq(&file->async_file->lock);
list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
list_del(&evt->list);
kfree(evt);
}
spin_unlock_irq(&file->async_file->lock);
ib_uverbs_release_uevent(file, uobj);
resp.events_reported = uobj->events_reported;

View file

@ -44,6 +44,7 @@
#include <linux/poll.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>
@ -63,6 +64,8 @@ enum {
#define IB_UVERBS_BASE_DEV MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
static struct class *uverbs_class;
DECLARE_MUTEX(ib_uverbs_idr_mutex);
DEFINE_IDR(ib_uverbs_pd_idr);
DEFINE_IDR(ib_uverbs_mr_idr);
@ -73,6 +76,7 @@ DEFINE_IDR(ib_uverbs_qp_idr);
DEFINE_IDR(ib_uverbs_srq_idr);
static spinlock_t map_lock;
static struct ib_uverbs_device *dev_table[IB_UVERBS_MAX_DEVICES];
static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
@ -110,7 +114,54 @@ static struct vfsmount *uverbs_event_mnt;
static void ib_uverbs_add_one(struct ib_device *device);
static void ib_uverbs_remove_one(struct ib_device *device);
static int ib_dealloc_ucontext(struct ib_ucontext *context)
static void ib_uverbs_release_dev(struct kref *ref)
{
struct ib_uverbs_device *dev =
container_of(ref, struct ib_uverbs_device, ref);
kfree(dev);
}
void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
struct ib_uverbs_event_file *ev_file,
struct ib_ucq_object *uobj)
{
struct ib_uverbs_event *evt, *tmp;
if (ev_file) {
spin_lock_irq(&ev_file->lock);
list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
list_del(&evt->list);
kfree(evt);
}
spin_unlock_irq(&ev_file->lock);
kref_put(&ev_file->ref, ib_uverbs_release_event_file);
}
spin_lock_irq(&file->async_file->lock);
list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
list_del(&evt->list);
kfree(evt);
}
spin_unlock_irq(&file->async_file->lock);
}
void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
struct ib_uevent_object *uobj)
{
struct ib_uverbs_event *evt, *tmp;
spin_lock_irq(&file->async_file->lock);
list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
list_del(&evt->list);
kfree(evt);
}
spin_unlock_irq(&file->async_file->lock);
}
static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
struct ib_ucontext *context)
{
struct ib_uobject *uobj, *tmp;
@ -129,26 +180,36 @@ static int ib_dealloc_ucontext(struct ib_ucontext *context)
list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
struct ib_qp *qp = idr_find(&ib_uverbs_qp_idr, uobj->id);
struct ib_uevent_object *uevent =
container_of(uobj, struct ib_uevent_object, uobject);
idr_remove(&ib_uverbs_qp_idr, uobj->id);
ib_destroy_qp(qp);
list_del(&uobj->list);
kfree(container_of(uobj, struct ib_uevent_object, uobject));
ib_uverbs_release_uevent(file, uevent);
kfree(uevent);
}
list_for_each_entry_safe(uobj, tmp, &context->cq_list, list) {
struct ib_cq *cq = idr_find(&ib_uverbs_cq_idr, uobj->id);
struct ib_uverbs_event_file *ev_file = cq->cq_context;
struct ib_ucq_object *ucq =
container_of(uobj, struct ib_ucq_object, uobject);
idr_remove(&ib_uverbs_cq_idr, uobj->id);
ib_destroy_cq(cq);
list_del(&uobj->list);
kfree(container_of(uobj, struct ib_ucq_object, uobject));
ib_uverbs_release_ucq(file, ev_file, ucq);
kfree(ucq);
}
list_for_each_entry_safe(uobj, tmp, &context->srq_list, list) {
struct ib_srq *srq = idr_find(&ib_uverbs_srq_idr, uobj->id);
struct ib_uevent_object *uevent =
container_of(uobj, struct ib_uevent_object, uobject);
idr_remove(&ib_uverbs_srq_idr, uobj->id);
ib_destroy_srq(srq);
list_del(&uobj->list);
kfree(container_of(uobj, struct ib_uevent_object, uobject));
ib_uverbs_release_uevent(file, uevent);
kfree(uevent);
}
/* XXX Free MWs */
@ -187,6 +248,8 @@ static void ib_uverbs_release_file(struct kref *ref)
container_of(ref, struct ib_uverbs_file, ref);
module_put(file->device->ib_dev->owner);
kref_put(&file->device->ref, ib_uverbs_release_dev);
kfree(file);
}
@ -552,36 +615,58 @@ static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
static int ib_uverbs_open(struct inode *inode, struct file *filp)
{
struct ib_uverbs_device *dev =
container_of(inode->i_cdev, struct ib_uverbs_device, dev);
struct ib_uverbs_device *dev;
struct ib_uverbs_file *file;
int ret;
if (!try_module_get(dev->ib_dev->owner))
return -ENODEV;
spin_lock(&map_lock);
dev = dev_table[iminor(inode) - IB_UVERBS_BASE_MINOR];
if (dev)
kref_get(&dev->ref);
spin_unlock(&map_lock);
if (!dev)
return -ENXIO;
if (!try_module_get(dev->ib_dev->owner)) {
ret = -ENODEV;
goto err;
}
file = kmalloc(sizeof *file, GFP_KERNEL);
if (!file) {
module_put(dev->ib_dev->owner);
return -ENOMEM;
ret = -ENOMEM;
goto err_module;
}
file->device = dev;
file->ucontext = NULL;
file->device = dev;
file->ucontext = NULL;
file->async_file = NULL;
kref_init(&file->ref);
init_MUTEX(&file->mutex);
filp->private_data = file;
return 0;
err_module:
module_put(dev->ib_dev->owner);
err:
kref_put(&dev->ref, ib_uverbs_release_dev);
return ret;
}
static int ib_uverbs_close(struct inode *inode, struct file *filp)
{
struct ib_uverbs_file *file = filp->private_data;
ib_dealloc_ucontext(file->ucontext);
ib_uverbs_cleanup_ucontext(file, file->ucontext);
if (file->async_file)
kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
kref_put(&file->ref, ib_uverbs_release_file);
return 0;
@ -610,8 +695,10 @@ static struct ib_client uverbs_client = {
static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
{
struct ib_uverbs_device *dev =
container_of(class_dev, struct ib_uverbs_device, class_dev);
struct ib_uverbs_device *dev = class_get_devdata(class_dev);
if (!dev)
return -ENODEV;
return sprintf(buf, "%s\n", dev->ib_dev->name);
}
@ -619,28 +706,15 @@ static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
static ssize_t show_dev_abi_version(struct class_device *class_dev, char *buf)
{
struct ib_uverbs_device *dev =
container_of(class_dev, struct ib_uverbs_device, class_dev);
struct ib_uverbs_device *dev = class_get_devdata(class_dev);
if (!dev)
return -ENODEV;
return sprintf(buf, "%d\n", dev->ib_dev->uverbs_abi_ver);
}
static CLASS_DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
static void ib_uverbs_release_class_dev(struct class_device *class_dev)
{
struct ib_uverbs_device *dev =
container_of(class_dev, struct ib_uverbs_device, class_dev);
cdev_del(&dev->dev);
clear_bit(dev->devnum, dev_map);
kfree(dev);
}
static struct class uverbs_class = {
.name = "infiniband_verbs",
.release = ib_uverbs_release_class_dev
};
static ssize_t show_abi_version(struct class *class, char *buf)
{
return sprintf(buf, "%d\n", IB_USER_VERBS_ABI_VERSION);
@ -660,6 +734,8 @@ static void ib_uverbs_add_one(struct ib_device *device)
memset(uverbs_dev, 0, sizeof *uverbs_dev);
kref_init(&uverbs_dev->ref);
spin_lock(&map_lock);
uverbs_dev->devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
if (uverbs_dev->devnum >= IB_UVERBS_MAX_DEVICES) {
@ -672,40 +748,45 @@ static void ib_uverbs_add_one(struct ib_device *device)
uverbs_dev->ib_dev = device;
uverbs_dev->num_comp_vectors = 1;
if (device->mmap)
cdev_init(&uverbs_dev->dev, &uverbs_mmap_fops);
else
cdev_init(&uverbs_dev->dev, &uverbs_fops);
uverbs_dev->dev.owner = THIS_MODULE;
kobject_set_name(&uverbs_dev->dev.kobj, "uverbs%d", uverbs_dev->devnum);
if (cdev_add(&uverbs_dev->dev, IB_UVERBS_BASE_DEV + uverbs_dev->devnum, 1))
uverbs_dev->dev = cdev_alloc();
if (!uverbs_dev->dev)
goto err;
uverbs_dev->class_dev.class = &uverbs_class;
uverbs_dev->class_dev.dev = device->dma_device;
uverbs_dev->class_dev.devt = uverbs_dev->dev.dev;
snprintf(uverbs_dev->class_dev.class_id, BUS_ID_SIZE, "uverbs%d", uverbs_dev->devnum);
if (class_device_register(&uverbs_dev->class_dev))
uverbs_dev->dev->owner = THIS_MODULE;
uverbs_dev->dev->ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
kobject_set_name(&uverbs_dev->dev->kobj, "uverbs%d", uverbs_dev->devnum);
if (cdev_add(uverbs_dev->dev, IB_UVERBS_BASE_DEV + uverbs_dev->devnum, 1))
goto err_cdev;
if (class_device_create_file(&uverbs_dev->class_dev, &class_device_attr_ibdev))
uverbs_dev->class_dev = class_device_create(uverbs_class, uverbs_dev->dev->dev,
device->dma_device,
"uverbs%d", uverbs_dev->devnum);
if (IS_ERR(uverbs_dev->class_dev))
goto err_cdev;
class_set_devdata(uverbs_dev->class_dev, uverbs_dev);
if (class_device_create_file(uverbs_dev->class_dev, &class_device_attr_ibdev))
goto err_class;
if (class_device_create_file(&uverbs_dev->class_dev, &class_device_attr_abi_version))
if (class_device_create_file(uverbs_dev->class_dev, &class_device_attr_abi_version))
goto err_class;
spin_lock(&map_lock);
dev_table[uverbs_dev->devnum] = uverbs_dev;
spin_unlock(&map_lock);
ib_set_client_data(device, &uverbs_client, uverbs_dev);
return;
err_class:
class_device_unregister(&uverbs_dev->class_dev);
class_device_destroy(uverbs_class, uverbs_dev->dev->dev);
err_cdev:
cdev_del(&uverbs_dev->dev);
cdev_del(uverbs_dev->dev);
clear_bit(uverbs_dev->devnum, dev_map);
err:
kfree(uverbs_dev);
kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
return;
}
@ -716,7 +797,16 @@ static void ib_uverbs_remove_one(struct ib_device *device)
if (!uverbs_dev)
return;
class_device_unregister(&uverbs_dev->class_dev);
class_set_devdata(uverbs_dev->class_dev, NULL);
class_device_destroy(uverbs_class, uverbs_dev->dev->dev);
cdev_del(uverbs_dev->dev);
spin_lock(&map_lock);
dev_table[uverbs_dev->devnum] = NULL;
spin_unlock(&map_lock);
clear_bit(uverbs_dev->devnum, dev_map);
kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
}
static struct super_block *uverbs_event_get_sb(struct file_system_type *fs_type, int flags,
@ -746,13 +836,14 @@ static int __init ib_uverbs_init(void)
goto out;
}
ret = class_register(&uverbs_class);
if (ret) {
uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
if (IS_ERR(uverbs_class)) {
ret = PTR_ERR(uverbs_class);
printk(KERN_ERR "user_verbs: couldn't create class infiniband_verbs\n");
goto out_chrdev;
}
ret = class_create_file(&uverbs_class, &class_attr_abi_version);
ret = class_create_file(uverbs_class, &class_attr_abi_version);
if (ret) {
printk(KERN_ERR "user_verbs: couldn't create abi_version attribute\n");
goto out_class;
@ -786,7 +877,7 @@ static int __init ib_uverbs_init(void)
unregister_filesystem(&uverbs_event_fs);
out_class:
class_unregister(&uverbs_class);
class_destroy(uverbs_class);
out_chrdev:
unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
@ -800,7 +891,7 @@ static void __exit ib_uverbs_cleanup(void)
ib_unregister_client(&uverbs_client);
mntput(uverbs_event_mnt);
unregister_filesystem(&uverbs_event_fs);
class_unregister(&uverbs_class);
class_destroy(uverbs_class);
unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
idr_destroy(&ib_uverbs_pd_idr);
idr_destroy(&ib_uverbs_mr_idr);