Merge tag 'char-misc-3.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...

[platform/adaptation/renesas_rcar/renesas_kernel.git] / fs / fuse / cuse.c

diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index ee8d550..e397b67 100644 (file)
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -45,7 +45,6 @@
 #include <linux/miscdevice.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
-#include <linux/spinlock.h>
 #include <linux/stat.h>
 #include <linux/module.h>
 
@@ -63,7 +62,7 @@ struct cuse_conn {
        bool                    unrestricted_ioctl;
 };
 
-static DEFINE_SPINLOCK(cuse_lock);             /* protects cuse_conntbl */
+static DEFINE_MUTEX(cuse_lock);                /* protects registration */
 static struct list_head cuse_conntbl[CUSE_CONNTBL_LEN];
 static struct class *cuse_class;
 
@@ -114,14 +113,14 @@ static int cuse_open(struct inode *inode, struct file *file)
        int rc;
 
        /* look up and get the connection */
-       spin_lock(&cuse_lock);
+       mutex_lock(&cuse_lock);
        list_for_each_entry(pos, cuse_conntbl_head(devt), list)
                if (pos->dev->devt == devt) {
                        fuse_conn_get(&pos->fc);
                        cc = pos;
                        break;
                }
-       spin_unlock(&cuse_lock);
+       mutex_unlock(&cuse_lock);
 
        /* dead? */
        if (!cc)
@@ -267,7 +266,7 @@ static int cuse_parse_one(char **pp, char *end, char **keyp, char **valp)
 static int cuse_parse_devinfo(char *p, size_t len, struct cuse_devinfo *devinfo)
 {
        char *end = p + len;
-       char *key, *val;
+       char *uninitialized_var(key), *uninitialized_var(val);
        int rc;
 
        while (true) {
@@ -305,14 +304,14 @@ static void cuse_gendev_release(struct device *dev)
  */
 static void cuse_process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 {
-       struct cuse_conn *cc = fc_to_cc(fc);
+       struct cuse_conn *cc = fc_to_cc(fc), *pos;
        struct cuse_init_out *arg = req->out.args[0].value;
        struct page *page = req->pages[0];
        struct cuse_devinfo devinfo = { };
        struct device *dev;
        struct cdev *cdev;
        dev_t devt;
-       int rc;
+       int rc, i;
 
        if (req->out.h.error ||
            arg->major != FUSE_KERNEL_VERSION || arg->minor < 11) {
@@ -356,15 +355,24 @@ static void cuse_process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
        dev_set_drvdata(dev, cc);
        dev_set_name(dev, "%s", devinfo.name);
 
+       mutex_lock(&cuse_lock);
+
+       /* make sure the device-name is unique */
+       for (i = 0; i < CUSE_CONNTBL_LEN; ++i) {
+               list_for_each_entry(pos, &cuse_conntbl[i], list)
+                       if (!strcmp(dev_name(pos->dev), dev_name(dev)))
+                               goto err_unlock;
+       }
+
        rc = device_add(dev);
        if (rc)
-               goto err_device;
+               goto err_unlock;
 
        /* register cdev */
        rc = -ENOMEM;
        cdev = cdev_alloc();
        if (!cdev)
-               goto err_device;
+               goto err_unlock;
 
        cdev->owner = THIS_MODULE;
        cdev->ops = &cuse_frontend_fops;
@@ -377,9 +385,8 @@ static void cuse_process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
        cc->cdev = cdev;
 
        /* make the device available */
-       spin_lock(&cuse_lock);
        list_add(&cc->list, cuse_conntbl_head(devt));
-       spin_unlock(&cuse_lock);
+       mutex_unlock(&cuse_lock);
 
        /* announce device availability */
        dev_set_uevent_suppress(dev, 0);
@@ -391,7 +398,8 @@ out:
 
 err_cdev:
        cdev_del(cdev);
-err_device:
+err_unlock:
+       mutex_unlock(&cuse_lock);
        put_device(dev);
 err_region:
        unregister_chrdev_region(devt, 1);
@@ -520,9 +528,9 @@ static int cuse_channel_release(struct inode *inode, struct file *file)
        int rc;
 
        /* remove from the conntbl, no more access from this point on */
-       spin_lock(&cuse_lock);
+       mutex_lock(&cuse_lock);
        list_del_init(&cc->list);
-       spin_unlock(&cuse_lock);
+       mutex_unlock(&cuse_lock);
 
        /* remove device */
        if (cc->dev)