Metadata cache and multiple metadata channels

[lttng-modules.git] / lib / ringbuffer / ring_buffer_splice.c

diff --git a/lib/ringbuffer/ring_buffer_splice.c b/lib/ringbuffer/ring_buffer_splice.c
index 5fa779f5a63e1038ad477abea8d7807a335fbf2c..3a7ff0c45cf86f7606d9d0751fe7a5db283daf3b 100644 (file)
--- a/lib/ringbuffer/ring_buffer_splice.c
+++ b/lib/ringbuffer/ring_buffer_splice.c
@@ -3,11 +3,24 @@
  *
  * Copyright (C) 2002-2005 - Tom Zanussi <zanussi@us.ibm.com>, IBM Corp
  * Copyright (C) 1999-2005 - Karim Yaghmour <karim@opersys.com>
- * Copyright (C) 2008-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2008-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
- * Re-using content from kernel/relay.c.
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
  *
- * This file is released under the GPL v2.
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Re-using code from kernel/relay.c, which is why it is licensed under
+ * the GPLv2.
  */
 
 #include <linux/module.h>
@@ -24,10 +37,12 @@
 #define printk_dbg(fmt, args...)
 #endif
 
-loff_t lib_ring_buffer_no_llseek(struct file *file, loff_t offset, int origin)
+loff_t vfs_lib_ring_buffer_no_llseek(struct file *file, loff_t offset,
+               int origin)
 {
        return -ESPIPE;
 }
+EXPORT_SYMBOL_GPL(vfs_lib_ring_buffer_no_llseek);
 
 /*
  * Release pages from the buffer so splice pipe_to_file can move them.
@@ -65,11 +80,11 @@ static int subbuf_splice_actor(struct file *in,
                               loff_t *ppos,
                               struct pipe_inode_info *pipe,
                               size_t len,
-                              unsigned int flags)
+                              unsigned int flags,
+                              struct lib_ring_buffer *buf)
 {
-       struct lib_ring_buffer *buf = in->private_data;
        struct channel *chan = buf->backend.chan;
-       const struct lib_ring_buffer_config *config = chan->backend.config;
+       const struct lib_ring_buffer_config *config = &chan->backend.config;
        unsigned int poff, subbuf_pages, nr_pages;
        struct page *pages[PIPE_DEF_BUFFERS];
        struct partial_page partial[PIPE_DEF_BUFFERS];
@@ -81,7 +96,7 @@ static int subbuf_splice_actor(struct file *in,
                .ops = &ring_buffer_pipe_buf_ops,
                .spd_release = lib_ring_buffer_page_release,
        };
-       unsigned long consumed_old, consumed_idx, roffset;
+       unsigned long consumed_old, roffset;
        unsigned long bytes_avail;
 
        /*
@@ -90,7 +105,6 @@ static int subbuf_splice_actor(struct file *in,
        WARN_ON(atomic_long_read(&buf->active_readers) != 1);
        consumed_old = lib_ring_buffer_get_consumed(config, buf);
        consumed_old += *ppos;
-       consumed_idx = subbuf_index(consumed_old, chan);
 
        /*
         * Adjust read len, if longer than what is available.
@@ -148,11 +162,11 @@ static int subbuf_splice_actor(struct file *in,
 
 ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
                                    struct pipe_inode_info *pipe, size_t len,
-                                   unsigned int flags)
+                                   unsigned int flags,
+                                   struct lib_ring_buffer *buf)
 {
-       struct lib_ring_buffer *buf = in->private_data;
        struct channel *chan = buf->backend.chan;
-       const struct lib_ring_buffer_config *config = chan->backend.config;
+       const struct lib_ring_buffer_config *config = &chan->backend.config;
        ssize_t spliced;
        int ret;
 
@@ -177,7 +191,7 @@ ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
        printk_dbg(KERN_DEBUG "SPLICE read len %zu pos %zd\n", len,
                   (ssize_t)*ppos);
        while (len && !spliced) {
-               ret = subbuf_splice_actor(in, ppos, pipe, len, flags);
+               ret = subbuf_splice_actor(in, ppos, pipe, len, flags, buf);
                printk_dbg(KERN_DEBUG "SPLICE read loop ret %d\n", ret);
                if (ret < 0)
                        break;
@@ -201,3 +215,13 @@ ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
        return ret;
 }
 EXPORT_SYMBOL_GPL(lib_ring_buffer_splice_read);
+
+ssize_t vfs_lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
+                                   struct pipe_inode_info *pipe, size_t len,
+                                   unsigned int flags)
+{
+       struct lib_ring_buffer *buf = in->private_data;
+
+       return lib_ring_buffer_splice_read(in, ppos, pipe, len, flags, buf);
+}
+EXPORT_SYMBOL_GPL(vfs_lib_ring_buffer_splice_read);