Version 2.4.4
[lttng-modules.git] / lttng-abi.c
index 45d78d9750c3473b71b3aa9469ada486e78767e0..9a6c8ee920fa0dee16fa4f086534cbc99f4348d0 100644 (file)
@@ -43,6 +43,7 @@
 #include <linux/file.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
+#include <linux/err.h>
 #include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
 #include "wrapper/ringbuffer/vfs.h"
 #include "wrapper/ringbuffer/backend.h"
@@ -52,6 +53,7 @@
 #include "lttng-abi-old.h"
 #include "lttng-events.h"
 #include "lttng-tracer.h"
+#include "lib/ringbuffer/frontend_types.h"
 
 /*
  * This is LTTng's own personal way to create a system call as an external
@@ -64,6 +66,7 @@ static const struct file_operations lttng_session_fops;
 static const struct file_operations lttng_channel_fops;
 static const struct file_operations lttng_metadata_fops;
 static const struct file_operations lttng_event_fops;
+static struct file_operations lttng_stream_ring_buffer_file_operations;
 
 /*
  * Teardown management: opened file descriptors keep a refcount on the module,
@@ -539,7 +542,7 @@ 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;
        }
 
@@ -547,21 +550,12 @@ unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
 }
 
 static
-int lttng_metadata_ring_buffer_ioctl_get_subbuf(struct file *filp,
+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;
-       struct lib_ring_buffer *buf = stream->priv;
-       struct channel *chan = buf->backend.chan;
-       struct lttng_channel *lttng_chan = channel_get_private(chan);
-       int ret;
 
-       ret = lttng_metadata_output_channel(lttng_chan, stream);
-       if (ret > 0) {
-               lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
-               ret = 0;
-       }
-       return ret;
+       stream->metadata_out = stream->metadata_in;
 }
 
 static
@@ -573,11 +567,38 @@ 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,
-                               cmd, arg);
+               struct lttng_metadata_stream *stream = filp->private_data;
+               struct lib_ring_buffer *buf = stream->priv;
+               struct channel *chan = buf->backend.chan;
+
+               ret = lttng_metadata_output_channel(stream, chan);
+               if (ret > 0) {
+                       lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
+                       ret = 0;
+               } else if (ret < 0)
+                       goto err;
+               break;
+       }
+       case RING_BUFFER_GET_SUBBUF:
+       {
+               /*
+                * Random access is not allowed for metadata channel.
+                */
+               return -ENOSYS;
+       }
+       case RING_BUFFER_FLUSH:
+       {
+               struct lttng_metadata_stream *stream = filp->private_data;
+               struct lib_ring_buffer *buf = stream->priv;
+               struct channel *chan = buf->backend.chan;
+
+               /*
+                * Before doing the actual ring buffer flush, write up to one
+                * packet of metadata in the ring buffer.
+                */
+               ret = lttng_metadata_output_channel(stream, chan);
                if (ret < 0)
                        goto err;
                break;
@@ -585,9 +606,23 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
        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;
 }
@@ -602,26 +637,56 @@ 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,
-                               cmd, arg);
-               if (ret < 0)
+               struct lttng_metadata_stream *stream = filp->private_data;
+               struct lib_ring_buffer *buf = stream->priv;
+               struct channel *chan = buf->backend.chan;
+
+               ret = lttng_metadata_output_channel(stream, chan);
+               if (ret > 0) {
+                       lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
+                       ret = 0;
+               } else 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;
 }
 #endif
 
+/*
+ * This is not used by anonymous file descriptors. This code is left
+ * there if we ever want to implement an inode with open() operation.
+ */
 static
 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
 {
@@ -629,6 +694,14 @@ int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
        struct lib_ring_buffer *buf = stream->priv;
 
        file->private_data = buf;
+       /*
+        * Since life-time of metadata cache differs from that of
+        * session, we need to keep our own reference on the transport.
+        */
+       if (!try_module_get(stream->transport->owner)) {
+               printk(KERN_WARNING "LTT : Can't lock transport module.\n");
+               return -EBUSY;
+       }
        return lib_ring_buffer_open(inode, file, buf);
 }
 
@@ -639,7 +712,7 @@ int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
        struct lib_ring_buffer *buf = stream->priv;
 
        kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
-
+       module_put(stream->transport->owner);
        return lib_ring_buffer_release(inode, file, buf);
 }
 
@@ -732,7 +805,7 @@ int lttng_abi_open_stream(struct file *channel_file)
 
        stream_priv = buf;
        ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
-                       &lib_ring_buffer_file_operations);
+                       &lttng_stream_ring_buffer_file_operations);
        if (ret < 0)
                goto fd_error;
 
@@ -759,12 +832,27 @@ int lttng_abi_open_metadata_stream(struct file *channel_file)
 
        metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
                        GFP_KERNEL);
-       if (!metadata_stream)
-               return -ENOMEM;
+       if (!metadata_stream) {
+               ret = -ENOMEM;
+               goto nomem;
+       }
        metadata_stream->metadata_cache = session->metadata_cache;
        init_waitqueue_head(&metadata_stream->read_wait);
        metadata_stream->priv = buf;
        stream_priv = metadata_stream;
+       metadata_stream->transport = channel->transport;
+       mutex_init(&metadata_stream->lock);
+
+       /*
+        * Since life-time of metadata cache differs from that of
+        * session, we need to keep our own reference on the transport.
+        */
+       if (!try_module_get(metadata_stream->transport->owner)) {
+               printk(KERN_WARNING "LTT : Can't lock transport module.\n");
+               ret = -EINVAL;
+               goto notransport;
+       }
+
        ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
                        &lttng_metadata_ring_buffer_file_operations);
        if (ret < 0)
@@ -776,6 +864,10 @@ int lttng_abi_open_metadata_stream(struct file *channel_file)
        return ret;
 
 fd_error:
+       module_put(metadata_stream->transport->owner);
+notransport:
+       kfree(metadata_stream);
+nomem:
        channel->ops->buffer_read_close(buf);
        return ret;
 }
@@ -822,8 +914,9 @@ int lttng_abi_create_event(struct file *channel_file,
                 * will stay invariant for the rest of the session.
                 */
                event = lttng_event_create(channel, event_param, NULL, NULL);
-               if (!event) {
-                       ret = -EINVAL;
+               WARN_ON_ONCE(!event);
+               if (IS_ERR(event)) {
+                       ret = PTR_ERR(event);
                        goto event_error;
                }
                event_file->private_data = event;
@@ -1244,6 +1337,206 @@ static const struct file_operations lttng_event_fops = {
 #endif
 };
 
+static int put_u64(uint64_t val, unsigned long arg)
+{
+       return put_user(val, (uint64_t __user *) arg);
+}
+
+static long lttng_stream_ring_buffer_ioctl(struct file *filp,
+               unsigned int cmd, unsigned long arg)
+{
+       struct lib_ring_buffer *buf = filp->private_data;
+       struct channel *chan = buf->backend.chan;
+       const struct lib_ring_buffer_config *config = &chan->backend.config;
+       const struct lttng_channel_ops *ops = chan->backend.priv_ops;
+       int ret;
+
+       if (atomic_read(&chan->record_disabled))
+               return -EIO;
+
+       switch (cmd) {
+       case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
+       {
+               uint64_t ts;
+
+               ret = ops->timestamp_begin(config, buf, &ts);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ts, arg);
+       }
+       case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
+       {
+               uint64_t ts;
+
+               ret = ops->timestamp_end(config, buf, &ts);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ts, arg);
+       }
+       case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
+       {
+               uint64_t ed;
+
+               ret = ops->events_discarded(config, buf, &ed);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ed, arg);
+       }
+       case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
+       {
+               uint64_t cs;
+
+               ret = ops->content_size(config, buf, &cs);
+               if (ret < 0)
+                       goto error;
+               return put_u64(cs, arg);
+       }
+       case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
+       {
+               uint64_t ps;
+
+               ret = ops->packet_size(config, buf, &ps);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ps, arg);
+       }
+       case LTTNG_RING_BUFFER_GET_STREAM_ID:
+       {
+               uint64_t si;
+
+               ret = ops->stream_id(config, buf, &si);
+               if (ret < 0)
+                       goto error;
+               return put_u64(si, arg);
+       }
+       case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
+       {
+               uint64_t ts;
+
+               ret = ops->current_timestamp(config, buf, &ts);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ts, arg);
+       }
+       default:
+               return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
+                               cmd, arg);
+       }
+
+error:
+       return -ENOSYS;
+}
+
+#ifdef CONFIG_COMPAT
+static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
+               unsigned int cmd, unsigned long arg)
+{
+       struct lib_ring_buffer *buf = filp->private_data;
+       struct channel *chan = buf->backend.chan;
+       const struct lib_ring_buffer_config *config = &chan->backend.config;
+       const struct lttng_channel_ops *ops = chan->backend.priv_ops;
+       int ret;
+
+       if (atomic_read(&chan->record_disabled))
+               return -EIO;
+
+       switch (cmd) {
+       case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
+       {
+               uint64_t ts;
+
+               ret = ops->timestamp_begin(config, buf, &ts);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ts, arg);
+       }
+       case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
+       {
+               uint64_t ts;
+
+               ret = ops->timestamp_end(config, buf, &ts);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ts, arg);
+       }
+       case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
+       {
+               uint64_t ed;
+
+               ret = ops->events_discarded(config, buf, &ed);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ed, arg);
+       }
+       case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
+       {
+               uint64_t cs;
+
+               ret = ops->content_size(config, buf, &cs);
+               if (ret < 0)
+                       goto error;
+               return put_u64(cs, arg);
+       }
+       case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
+       {
+               uint64_t ps;
+
+               ret = ops->packet_size(config, buf, &ps);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ps, arg);
+       }
+       case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
+       {
+               uint64_t si;
+
+               ret = ops->stream_id(config, buf, &si);
+               if (ret < 0)
+                       goto error;
+               return put_u64(si, arg);
+       }
+       case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
+       {
+               uint64_t ts;
+
+               ret = ops->current_timestamp(config, buf, &ts);
+               if (ret < 0)
+                       goto error;
+               return put_u64(ts, arg);
+       }
+       default:
+               return lib_ring_buffer_file_operations.compat_ioctl(filp,
+                               cmd, arg);
+       }
+
+error:
+       return -ENOSYS;
+}
+#endif /* CONFIG_COMPAT */
+
+static void lttng_stream_override_ring_buffer_fops(void)
+{
+       lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
+       lttng_stream_ring_buffer_file_operations.open =
+               lib_ring_buffer_file_operations.open;
+       lttng_stream_ring_buffer_file_operations.release =
+               lib_ring_buffer_file_operations.release;
+       lttng_stream_ring_buffer_file_operations.poll =
+               lib_ring_buffer_file_operations.poll;
+       lttng_stream_ring_buffer_file_operations.splice_read =
+               lib_ring_buffer_file_operations.splice_read;
+       lttng_stream_ring_buffer_file_operations.mmap =
+               lib_ring_buffer_file_operations.mmap;
+       lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
+               lttng_stream_ring_buffer_ioctl;
+       lttng_stream_ring_buffer_file_operations.llseek =
+               lib_ring_buffer_file_operations.llseek;
+#ifdef CONFIG_COMPAT
+       lttng_stream_ring_buffer_file_operations.compat_ioctl =
+               lttng_stream_ring_buffer_compat_ioctl;
+#endif
+}
+
 int __init lttng_abi_init(void)
 {
        int ret = 0;
@@ -1257,6 +1550,8 @@ int __init lttng_abi_init(void)
                ret = -ENOMEM;
                goto error;
        }
+       lttng_stream_override_ring_buffer_fops();
+
 error:
        return ret;
 }
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