switch infiniband uverbs to anon_inodes

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 29 insertions, 81 deletions

diff --git a/drivers/infiniband/Kconfig b/drivers/infiniband/Kconfig
index dd0db67bf8d7..975adce5f40c 100644
--- a/drivers/infiniband/Kconfig
+++ b/drivers/infiniband/Kconfig
@@ -20,6 +20,7 @@ config INFINIBAND_USER_MAD
 
 config INFINIBAND_USER_ACCESS
         tristate "InfiniBand userspace access (verbs and CM)"
+        select ANON_INODES
         ---help---
           Userspace InfiniBand access support.  This enables the
           kernel side of userspace verbs and the userspace
diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index b3ea9587dc80..0b3862080c0f 100644
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -145,7 +145,7 @@ extern struct idr ib_uverbs_srq_idr;
 void idr_remove_uobj(struct idr *idp, struct ib_uobject *uobj);
 
 struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
-                                        int is_async, int *fd);
+                                        int is_async);
 struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd);
 
 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 112d3970222a..f71cf138d674 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -301,10 +301,15 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
 
         resp.num_comp_vectors = file->device->num_comp_vectors;
 
-        filp = ib_uverbs_alloc_event_file(file, 1, &resp.async_fd);
+        ret = get_unused_fd();
+        if (ret < 0)
+                goto err_free;
+        resp.async_fd = ret;
+
+        filp = ib_uverbs_alloc_event_file(file, 1);
         if (IS_ERR(filp)) {
                 ret = PTR_ERR(filp);
-                goto err_free;
+                goto err_fd;
         }
 
         if (copy_to_user((void __user *) (unsigned long) cmd.response,
@@ -332,9 +337,11 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
         return in_len;
 
 err_file:
-        put_unused_fd(resp.async_fd);
         fput(filp);
 
+err_fd:
+        put_unused_fd(resp.async_fd);
+
 err_free:
         ibdev->dealloc_ucontext(ucontext);
 
@@ -715,6 +722,7 @@ ssize_t ib_uverbs_create_comp_channel(struct ib_uverbs_file *file,
         struct ib_uverbs_create_comp_channel       cmd;
         struct ib_uverbs_create_comp_channel_resp  resp;
         struct file                               *filp;
+        int ret;
 
         if (out_len < sizeof resp)
                 return -ENOSPC;
@@ -722,9 +730,16 @@ ssize_t ib_uverbs_create_comp_channel(struct ib_uverbs_file *file,
         if (copy_from_user(&cmd, buf, sizeof cmd))
                 return -EFAULT;
 
-        filp = ib_uverbs_alloc_event_file(file, 0, &resp.fd);
-        if (IS_ERR(filp))
+        ret = get_unused_fd();
+        if (ret < 0)
+                return ret;
+        resp.fd = ret;
+
+        filp = ib_uverbs_alloc_event_file(file, 0);
+        if (IS_ERR(filp)) {
+                put_unused_fd(resp.fd);
                 return PTR_ERR(filp);
+        }
 
         if (copy_to_user((void __user *) (unsigned long) cmd.response,
                          &resp, sizeof resp)) {
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 5f284ffd430e..810f277739e2 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -41,8 +41,8 @@
 #include <linux/fs.h>
 #include <linux/poll.h>
 #include <linux/sched.h>
+#include <linux/anon_inodes.h>
 #include <linux/file.h>
-#include <linux/mount.h>
 #include <linux/cdev.h>
 
 #include <asm/uaccess.h>
@@ -53,8 +53,6 @@ MODULE_AUTHOR("Roland Dreier");
 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
 MODULE_LICENSE("Dual BSD/GPL");
 
-#define INFINIBANDEVENTFS_MAGIC 0x49426576      /* "IBev" */
-
 enum {
         IB_UVERBS_MAJOR       = 231,
         IB_UVERBS_BASE_MINOR  = 192,
@@ -111,8 +109,6 @@ static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
         [IB_USER_VERBS_CMD_DESTROY_SRQ]         = ib_uverbs_destroy_srq,
 };
 
-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);
 
@@ -489,12 +485,10 @@ void ib_uverbs_event_handler(struct ib_event_handler *handler,
 }
 
 struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
-                                        int is_async, int *fd)
+                                        int is_async)
 {
         struct ib_uverbs_event_file *ev_file;
-        struct path path;
         struct file *filp;
-        int ret;
 
         ev_file = kmalloc(sizeof *ev_file, GFP_KERNEL);
         if (!ev_file)
@@ -509,38 +503,12 @@ struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
         ev_file->is_async    = is_async;
         ev_file->is_closed   = 0;
 
-        *fd = get_unused_fd();
-        if (*fd < 0) {
-                ret = *fd;
-                goto err;
-        }
-
-        /*
-         * fops_get() can't fail here, because we're coming from a
-         * system call on a uverbs file, which will already have a
-         * module reference.
-         */
-        path.mnt = uverbs_event_mnt;
-        path.dentry = uverbs_event_mnt->mnt_root;
-        path_get(&path);
-        filp = alloc_file(&path, FMODE_READ, fops_get(&uverbs_event_fops));
-        if (!filp) {
-                ret = -ENFILE;
-                goto err_fd;
-        }
-
-        filp->private_data = ev_file;
+        filp = anon_inode_getfile("[infinibandevent]", &uverbs_event_fops,
+                                  ev_file, O_RDONLY);
+        if (IS_ERR(filp))
+                kfree(ev_file);
 
         return filp;
-
-err_fd:
-        fops_put(&uverbs_event_fops);
-        path_put(&path);
-        put_unused_fd(*fd);
-
-err:
-        kfree(ev_file);
-        return ERR_PTR(ret);
 }
 
 /*
@@ -825,21 +793,6 @@ static void ib_uverbs_remove_one(struct ib_device *device)
         kfree(uverbs_dev);
 }
 
-static int uverbs_event_get_sb(struct file_system_type *fs_type, int flags,
-                               const char *dev_name, void *data,
-                               struct vfsmount *mnt)
-{
-        return get_sb_pseudo(fs_type, "infinibandevent:", NULL,
-                             INFINIBANDEVENTFS_MAGIC, mnt);
-}
-
-static struct file_system_type uverbs_event_fs = {
-        /* No owner field so module can be unloaded */
-        .name    = "infinibandeventfs",
-        .get_sb  = uverbs_event_get_sb,
-        .kill_sb = kill_litter_super
-};
-
 static int __init ib_uverbs_init(void)
 {
         int ret;
@@ -864,33 +817,14 @@ static int __init ib_uverbs_init(void)
                 goto out_class;
         }
 
-        ret = register_filesystem(&uverbs_event_fs);
-        if (ret) {
-                printk(KERN_ERR "user_verbs: couldn't register infinibandeventfs\n");
-                goto out_class;
-        }
-
-        uverbs_event_mnt = kern_mount(&uverbs_event_fs);
-        if (IS_ERR(uverbs_event_mnt)) {
-                ret = PTR_ERR(uverbs_event_mnt);
-                printk(KERN_ERR "user_verbs: couldn't mount infinibandeventfs\n");
-                goto out_fs;
-        }
-
         ret = ib_register_client(&uverbs_client);
         if (ret) {
                 printk(KERN_ERR "user_verbs: couldn't register client\n");
-                goto out_mnt;
+                goto out_class;
         }
 
         return 0;
 
-out_mnt:
-        mntput(uverbs_event_mnt);
-
-out_fs:
-        unregister_filesystem(&uverbs_event_fs);
-
 out_class:
         class_destroy(uverbs_class);
 
@@ -904,8 +838,6 @@ out:
 static void __exit ib_uverbs_cleanup(void)
 {
         ib_unregister_client(&uverbs_client);
-        mntput(uverbs_event_mnt);
-        unregister_filesystem(&uverbs_event_fs);
         class_destroy(uverbs_class);
         unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
         idr_destroy(&ib_uverbs_pd_idr);