1 files changed, 58 insertions, 11 deletions

diff --git a/fs/relayfs/relay.c b/fs/relayfs/relay.c
index 2a6f7f12b7f945..abf3ceaace4916 100644
--- a/fs/relayfs/relay.c
+++ b/fs/relayfs/relay.c
@@ -80,11 +80,34 @@ static void buf_unmapped_default_callback(struct rchan_buf *buf,
 {
 }
 
+/*
+ * create_buf_file_create() default callback.  Creates file to represent buf.
+ */
+static struct dentry *create_buf_file_default_callback(const char *filename,
+						       struct dentry *parent,
+						       int mode,
+						       struct rchan_buf *buf,
+						       int *is_global)
+{
+	return relayfs_create_file(filename, parent, mode,
+				   &relay_file_operations, buf);
+}
+
+/*
+ * remove_buf_file() default callback.  Removes file representing relay buffer.
+ */
+static int remove_buf_file_default_callback(struct dentry *dentry)
+{
+	return relayfs_remove(dentry);
+}
+
 /* relay channel default callbacks */
 static struct rchan_callbacks default_channel_callbacks = {
 	.subbuf_start = subbuf_start_default_callback,
 	.buf_mapped = buf_mapped_default_callback,
 	.buf_unmapped = buf_unmapped_default_callback,
+	.create_buf_file = create_buf_file_default_callback,
+	.remove_buf_file = remove_buf_file_default_callback,
 };
 
 /**
@@ -148,14 +171,16 @@ static inline void __relay_reset(struct rchan_buf *buf, unsigned int init)
 void relay_reset(struct rchan *chan)
 {
 	unsigned int i;
+	struct rchan_buf *prev = NULL;
 
 	if (!chan)
 		return;
 
 	for (i = 0; i < NR_CPUS; i++) {
-		if (!chan->buf[i])
-			continue;
+		if (!chan->buf[i] || chan->buf[i] == prev)
+			break;
 		__relay_reset(chan->buf[i], 0);
+		prev = chan->buf[i];
 	}
 }
 
@@ -166,17 +191,27 @@ void relay_reset(struct rchan *chan)
  */
 static struct rchan_buf *relay_open_buf(struct rchan *chan,
 					const char *filename,
-					struct dentry *parent)
+					struct dentry *parent,
+					int *is_global)
 {
 	struct rchan_buf *buf;
 	struct dentry *dentry;
 
+	if (*is_global)
+		return chan->buf[0];
+
+ 	buf = relay_create_buf(chan);
+ 	if (!buf)
+ 		return NULL;
+
 	/* Create file in fs */
-	dentry = relayfs_create_file(filename, parent, S_IRUSR, chan);
-	if (!dentry)
+ 	dentry = chan->cb->create_buf_file(filename, parent, S_IRUSR,
+ 					   buf, is_global);
+ 	if (!dentry) {
+ 		relay_destroy_buf(buf);
 		return NULL;
+ 	}
 
-	buf = RELAYFS_I(dentry->d_inode)->buf;
 	buf->dentry = dentry;
 	__relay_reset(buf, 1);
 
@@ -214,6 +249,10 @@ static inline void setup_callbacks(struct rchan *chan,
 		cb->buf_mapped = buf_mapped_default_callback;
 	if (!cb->buf_unmapped)
 		cb->buf_unmapped = buf_unmapped_default_callback;
+	if (!cb->create_buf_file)
+		cb->create_buf_file = create_buf_file_default_callback;
+	if (!cb->remove_buf_file)
+		cb->remove_buf_file = remove_buf_file_default_callback;
 	chan->cb = cb;
 }
 
@@ -241,6 +280,7 @@ struct rchan *relay_open(const char *base_filename,
 	unsigned int i;
 	struct rchan *chan;
 	char *tmpname;
+	int is_global = 0;
 
 	if (!base_filename)
 		return NULL;
@@ -265,7 +305,8 @@ struct rchan *relay_open(const char *base_filename,
 
 	for_each_online_cpu(i) {
 		sprintf(tmpname, "%s%d", base_filename, i);
-		chan->buf[i] = relay_open_buf(chan, tmpname, parent);
+		chan->buf[i] = relay_open_buf(chan, tmpname, parent,
+					      &is_global);
 		chan->buf[i]->cpu = i;
 		if (!chan->buf[i])
 			goto free_bufs;
@@ -279,6 +320,8 @@ free_bufs:
 		if (!chan->buf[i])
 			break;
 		relay_close_buf(chan->buf[i]);
+		if (is_global)
+			break;
 	}
 	kfree(tmpname);
 
@@ -388,14 +431,16 @@ void relay_destroy_channel(struct kref *kref)
 void relay_close(struct rchan *chan)
 {
 	unsigned int i;
+	struct rchan_buf *prev = NULL;
 
 	if (!chan)
 		return;
 
 	for (i = 0; i < NR_CPUS; i++) {
-		if (!chan->buf[i])
-			continue;
+		if (!chan->buf[i] || chan->buf[i] == prev)
+			break;
 		relay_close_buf(chan->buf[i]);
+		prev = chan->buf[i];
 	}
 
 	if (chan->last_toobig)
@@ -415,14 +460,16 @@ void relay_close(struct rchan *chan)
 void relay_flush(struct rchan *chan)
 {
 	unsigned int i;
+	struct rchan_buf *prev = NULL;
 
 	if (!chan)
 		return;
 
 	for (i = 0; i < NR_CPUS; i++) {
-		if (!chan->buf[i])
-			continue;
+		if (!chan->buf[i] || chan->buf[i] == prev)
+			break;
 		relay_switch_subbuf(chan->buf[i], 0);
+		prev = chan->buf[i];
 	}
 }