Fix: add "flush empty" ioctl for stream intersection

[lttng-modules.git] / lib / ringbuffer / vfs.h

diff --git a/lib/ringbuffer/vfs.h b/lib/ringbuffer/vfs.h
index 204c57a81f6e9c11e968c1609c675551c02cb791..b2e5b1c84810a606b4368a84673bc8dca410ccb6 100644 (file)
--- a/lib/ringbuffer/vfs.h
+++ b/lib/ringbuffer/vfs.h
@@ -111,7 +111,7 @@ ssize_t vfs_lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
 #define RING_BUFFER_GET_MMAP_LEN               _IOR(0xF6, 0x0A, unsigned long)
 /* returns the offset of the subbuffer belonging to the mmap reader. */
 #define RING_BUFFER_GET_MMAP_READ_OFFSET       _IOR(0xF6, 0x0B, unsigned long)
-/* flush the current sub-buffer */
+/* Flush the current sub-buffer, if non-empty. */
 #define RING_BUFFER_FLUSH                      _IO(0xF6, 0x0C)
 /* Get the current version of the metadata cache (after a get_next). */
 #define RING_BUFFER_GET_METADATA_VERSION       _IOR(0xF6, 0x0D, uint64_t)
@@ -121,6 +121,8 @@ ssize_t vfs_lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
  * sub-buffer.
  */
 #define RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS  _IO(0xF6, 0x0E)
+/* Flush the current sub-buffer, even if empty. */
+#define RING_BUFFER_FLUSH_EMPTY                        _IO(0xF6, 0x0F)
 
 #ifdef CONFIG_COMPAT
 /* Get a snapshot of the current ring buffer producer and consumer positions */
@@ -151,7 +153,7 @@ ssize_t vfs_lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
 #define RING_BUFFER_COMPAT_GET_MMAP_LEN                _IOR(0xF6, 0x0A, compat_ulong_t)
 /* returns the offset of the subbuffer belonging to the mmap reader. */
 #define RING_BUFFER_COMPAT_GET_MMAP_READ_OFFSET        _IOR(0xF6, 0x0B, compat_ulong_t)
-/* flush the current sub-buffer */
+/* Flush the current sub-buffer, if non-empty. */
 #define RING_BUFFER_COMPAT_FLUSH               RING_BUFFER_FLUSH
 /* Get the current version of the metadata cache (after a get_next). */
 #define RING_BUFFER_COMPAT_GET_METADATA_VERSION        RING_BUFFER_GET_METADATA_VERSION
@@ -162,6 +164,9 @@ ssize_t vfs_lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
  */
 #define RING_BUFFER_COMPAT_SNAPSHOT_SAMPLE_POSITIONS   \
        RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS
+/* Flush the current sub-buffer, even if empty. */
+#define RING_BUFFER_COMPAT_FLUSH_EMPTY                 \
+       RING_BUFFER_FLUSH_EMPTY
 #endif /* CONFIG_COMPAT */
 
 #endif /* _LIB_RING_BUFFER_VFS_H */