Fix: allow get/put subbuf in loop for metadata stream

[lttng-modules.git] / lttng-abi.c

diff --git a/lttng-abi.c b/lttng-abi.c
index 45d78d9750c3473b71b3aa9469ada486e78767e0..ba8362b167a3fd9a42612bc5c2631fedd4cb0bee 100644 (file)
--- a/lttng-abi.c
+++ b/lttng-abi.c
@@ -539,7 +539,7 @@ unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
                        mask |= POLLHUP;
 
                if (stream->metadata_cache->metadata_written >
-                               stream->metadata_cache_read)
+                               stream->metadata_out)
                        mask |= POLLIN;
        }
 
@@ -547,7 +547,7 @@ unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
 }
 
 static
-int lttng_metadata_ring_buffer_ioctl_get_subbuf(struct file *filp,
+int lttng_metadata_ring_buffer_ioctl_get_next_subbuf(struct file *filp,
                unsigned int cmd, unsigned long arg)
 {
        struct lttng_metadata_stream *stream = filp->private_data;
@@ -564,6 +564,15 @@ int lttng_metadata_ring_buffer_ioctl_get_subbuf(struct file *filp,
        return ret;
 }
 
+static
+void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
+               unsigned int cmd, unsigned long arg)
+{
+       struct lttng_metadata_stream *stream = filp->private_data;
+
+       stream->metadata_out = stream->metadata_in;
+}
+
 static
 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
                unsigned int cmd, unsigned long arg)
@@ -573,21 +582,41 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
        struct lib_ring_buffer *buf = stream->priv;
 
        switch (cmd) {
-       case RING_BUFFER_GET_SUBBUF:
        case RING_BUFFER_GET_NEXT_SUBBUF:
        {
-               ret = lttng_metadata_ring_buffer_ioctl_get_subbuf(filp,
+               ret = lttng_metadata_ring_buffer_ioctl_get_next_subbuf(filp,
                                cmd, arg);
                if (ret < 0)
                        goto err;
                break;
        }
+       case RING_BUFFER_GET_SUBBUF:
+       {
+               /*
+                * Random access is not allowed for metadata channel.
+                */
+               return -ENOSYS;
+       }
        default:
                break;
        }
+       /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
+
        /* Performing lib ring buffer ioctl after our own. */
-       return lib_ring_buffer_ioctl(filp, cmd, arg, buf);
+       ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
+       if (ret < 0)
+               goto err;
 
+       switch (cmd) {
+       case RING_BUFFER_PUT_NEXT_SUBBUF:
+       {
+               lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
+                               cmd, arg);
+               break;
+       }
+       default:
+               break;
+       }
 err:
        return ret;
 }
@@ -602,21 +631,41 @@ long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
        struct lib_ring_buffer *buf = stream->priv;
 
        switch (cmd) {
-       case RING_BUFFER_GET_SUBBUF:
        case RING_BUFFER_GET_NEXT_SUBBUF:
        {
-               ret = lttng_metadata_ring_buffer_ioctl_get_subbuf(filp,
+               ret = lttng_metadata_ring_buffer_ioctl_get_next_subbuf(filp,
                                cmd, arg);
                if (ret < 0)
                        goto err;
                break;
        }
+       case RING_BUFFER_GET_SUBBUF:
+       {
+               /*
+                * Random access is not allowed for metadata channel.
+                */
+               return -ENOSYS;
+       }
        default:
                break;
        }
+       /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
+
        /* Performing lib ring buffer ioctl after our own. */
-       return lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
+       ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
+       if (ret < 0)
+               goto err;
 
+       switch (cmd) {
+       case RING_BUFFER_PUT_NEXT_SUBBUF:
+       {
+               lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
+                               cmd, arg);
+               break;
+       }
+       default:
+               break;
+       }
 err:
        return ret;
 }