X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Fring_buffer_vfs.c;h=034c6fdd15d4c9a23680190c12811907c4685253;hb=886d51a3d7ed5fa6b41d7f19b3e14ae6c535a44c;hp=6a9fb469ca4f73ccc4940b755a3607ec4bf3784d;hpb=f3bc08c50e1b302bceea699027d889fd6d9af525;p=lttng-modules.git

diff --git a/lib/ringbuffer/ring_buffer_vfs.c b/lib/ringbuffer/ring_buffer_vfs.c
index 6a9fb469..034c6fdd 100644
--- a/lib/ringbuffer/ring_buffer_vfs.c
+++ b/lib/ringbuffer/ring_buffer_vfs.c
@@ -1,11 +1,23 @@
 /*
  * ring_buffer_vfs.c
  *
- * Copyright (C) 2009-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
  * Ring Buffer VFS file operations.
  *
- * Dual LGPL v2.1/GPL v2 license.
+ * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * 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 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
  */
 
 #include <linux/module.h>
@@ -42,6 +54,9 @@ int lib_ring_buffer_open(struct inode *inode, struct file *file)
 	struct lib_ring_buffer *buf = inode->i_private;
 	int ret;
 
+	if (!buf)
+		return -EINVAL;
+
 	ret = lib_ring_buffer_open_read(buf);
 	if (ret)
 		return ret;
@@ -85,20 +100,25 @@ unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait)
 	unsigned int mask = 0;
 	struct lib_ring_buffer *buf = filp->private_data;
 	struct channel *chan = buf->backend.chan;
-	const struct lib_ring_buffer_config *config = chan->backend.config;
-	int finalized;
+	const struct lib_ring_buffer_config *config = &chan->backend.config;
+	int finalized, disabled;
 
 	if (filp->f_mode & FMODE_READ) {
 		poll_wait_set_exclusive(wait);
 		poll_wait(filp, &buf->read_wait, wait);
 
 		finalized = lib_ring_buffer_is_finalized(config, buf);
+		disabled = lib_ring_buffer_channel_is_disabled(chan);
+
 		/*
 		 * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering
 		 * finalized load before offsets loads.
 		 */
 		WARN_ON(atomic_long_read(&buf->active_readers) != 1);
 retry:
+		if (disabled)
+			return POLLERR;
+
 		if (subbuf_trunc(lib_ring_buffer_get_offset(config, buf), chan)
 		  - subbuf_trunc(lib_ring_buffer_get_consumed(config, buf), chan)
 		  == 0) {
@@ -157,7 +177,10 @@ long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, unsigned long ar
 {
 	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 lib_ring_buffer_config *config = &chan->backend.config;
+
+	if (lib_ring_buffer_channel_is_disabled(chan))
+		return -EIO;
 
 	switch (cmd) {
 	case RING_BUFFER_SNAPSHOT:
@@ -237,6 +260,9 @@ long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, unsigned long ar
 		return put_ulong(buf->backend.array[sb_bindex]->mmap_offset,
 				 arg);
 	}
+	case RING_BUFFER_FLUSH:
+		lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
+		return 0;
 	default:
 		return -ENOIOCTLCMD;
 	}
@@ -248,7 +274,10 @@ long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
 {
 	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 lib_ring_buffer_config *config = &chan->backend.config;
+
+	if (lib_ring_buffer_channel_is_disabled(chan))
+		return -EIO;
 
 	switch (cmd) {
 	case RING_BUFFER_SNAPSHOT:
@@ -344,6 +373,9 @@ long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
 			return -EINVAL;
 		return put_ulong(read_offset, arg);
 	}
+	case RING_BUFFER_FLUSH:
+		lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
+		return 0;
 	default:
 		return -ENOIOCTLCMD;
 	}
@@ -351,6 +383,7 @@ long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
 #endif
 
 const struct file_operations lib_ring_buffer_file_operations = {
+	.owner = THIS_MODULE,
 	.open = lib_ring_buffer_open,
 	.release = lib_ring_buffer_release,
 	.poll = lib_ring_buffer_poll,