[PATCH] relayfs: add support for global relay buffers

[linux-2.6-omap-h63xx.git] / fs / relayfs / relay.c

diff --git a/fs/relayfs/relay.c b/fs/relayfs/relay.c
index b9bb569032729ec541124855a169d96589214eff..2935a6ab8ffab629d3d7d5f7cd312d567bb37941 100644 (file)
--- a/fs/relayfs/relay.c
+++ b/fs/relayfs/relay.c
@@ -86,7 +86,8 @@ static void buf_unmapped_default_callback(struct rchan_buf *buf,
 static struct dentry *create_buf_file_default_callback(const char *filename,
                                                       struct dentry *parent,
                                                       int mode,
-                                                      struct rchan_buf *buf)
+                                                      struct rchan_buf *buf,
+                                                      int *is_global)
 {
        return relayfs_create_file(filename, parent, mode,
                                   &relayfs_file_operations, buf);
@@ -170,14 +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];
        }
 }
 
@@ -188,18 +191,22 @@ 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 = chan->cb->create_buf_file(filename, parent, S_IRUSR,
-                                          buf);
+                                          buf, is_global);
        if (!dentry) {
                relay_destroy_buf(buf);
                return NULL;
@@ -273,6 +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;
@@ -297,7 +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;
@@ -311,6 +320,8 @@ free_bufs:
                if (!chan->buf[i])
                        break;
                relay_close_buf(chan->buf[i]);
+               if (is_global)
+                       break;
        }
        kfree(tmpname);
 
@@ -420,14 +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)
@@ -447,14 +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];
        }
 }