ieee1394: raw1394: fix possible deadlock in multithreaded clients

[pandora-kernel.git] / drivers / ieee1394 / raw1394.c

diff --git a/drivers/ieee1394/raw1394.c b/drivers/ieee1394/raw1394.c
index 2cf4ae7..4bdfff0 100644 (file)
--- a/drivers/ieee1394/raw1394.c
+++ b/drivers/ieee1394/raw1394.c
@@ -2268,7 +2268,8 @@ static ssize_t raw1394_write(struct file *file, const char __user * buffer,
                return -EFAULT;
        }
 
-       mutex_lock(&fi->state_mutex);
+       if (!mutex_trylock(&fi->state_mutex))
+               return -EAGAIN;
 
        switch (fi->state) {
        case opened:
@@ -2548,7 +2549,8 @@ static int raw1394_mmap(struct file *file, struct vm_area_struct *vma)
        struct file_info *fi = file->private_data;
        int ret;
 
-       mutex_lock(&fi->state_mutex);
+       if (!mutex_trylock(&fi->state_mutex))
+               return -EAGAIN;
 
        if (fi->iso_state == RAW1394_ISO_INACTIVE)
                ret = -EINVAL;
@@ -2669,7 +2671,8 @@ static long raw1394_ioctl(struct file *file, unsigned int cmd,
                break;
        }
 
-       mutex_lock(&fi->state_mutex);
+       if (!mutex_trylock(&fi->state_mutex))
+               return -EAGAIN;
 
        switch (fi->iso_state) {
        case RAW1394_ISO_INACTIVE: