1 files changed, 64 insertions, 13 deletions

diff --git a/fs/relayfs/relay.c b/fs/relayfs/relay.c
index 16446a15c96d..abf3ceaace49 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);
 
@@ -333,8 +376,7 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
         return length;
 
 toobig:
-        printk(KERN_WARNING "relayfs: event too large (%Zd)\n", length);
-        WARN_ON(1);
+        buf->chan->last_toobig = length;
         return 0;
 }
 
@@ -389,16 +431,23 @@ 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)
+                printk(KERN_WARNING "relayfs: one or more items not logged "
+                       "[item size (%Zd) > sub-buffer size (%Zd)]\n",
+                       chan->last_toobig, chan->subbuf_size);
+
         kref_put(&chan->kref, relay_destroy_channel);
 }
 
@@ -411,14 +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];
         }
 }