4 files changed, 165 insertions, 145 deletions

diff --git a/fs/relayfs/buffers.c b/fs/relayfs/buffers.c
index 84e21ffa5ca8..10187812771e 100644
--- a/fs/relayfs/buffers.c
+++ b/fs/relayfs/buffers.c
@@ -185,5 +185,6 @@ void relay_destroy_buf(struct rchan_buf *buf)
 void relay_remove_buf(struct kref *kref)
 {
         struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref);
-        relayfs_remove(buf->dentry);
+        buf->chan->cb->remove_buf_file(buf->dentry);
+        relay_destroy_buf(buf);
 }
diff --git a/fs/relayfs/inode.c b/fs/relayfs/inode.c
index 0f7f88d067ad..383523011aad 100644
--- a/fs/relayfs/inode.c
+++ b/fs/relayfs/inode.c
@@ -26,31 +26,22 @@
 
 static struct vfsmount *                relayfs_mount;
 static int                              relayfs_mount_count;
-static kmem_cache_t *                   relayfs_inode_cachep;
 
 static struct backing_dev_info          relayfs_backing_dev_info = {
         .ra_pages       = 0,    /* No readahead */
         .capabilities   = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
 };
 
-static struct inode *relayfs_get_inode(struct super_block *sb, int mode,
-                                       struct rchan *chan)
+static struct inode *relayfs_get_inode(struct super_block *sb,
+                                       int mode,
+                                       struct file_operations *fops,
+                                       void *data)
 {
-        struct rchan_buf *buf = NULL;
         struct inode *inode;
 
-        if (S_ISREG(mode)) {
-                BUG_ON(!chan);
-                buf = relay_create_buf(chan);
-                if (!buf)
-                        return NULL;
-        }
-
         inode = new_inode(sb);
-        if (!inode) {
-                relay_destroy_buf(buf);
+        if (!inode)
                 return NULL;
-        }
 
         inode->i_mode = mode;
         inode->i_uid = 0;
@@ -61,8 +52,9 @@ static struct inode *relayfs_get_inode(struct super_block *sb, int mode,
         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
         switch (mode & S_IFMT) {
         case S_IFREG:
-                inode->i_fop = &relayfs_file_operations;
-                RELAYFS_I(inode)->buf = buf;
+                inode->i_fop = fops;
+                if (data)
+                        inode->u.generic_ip = data;
                 break;
         case S_IFDIR:
                 inode->i_op = &simple_dir_inode_operations;
@@ -83,7 +75,8 @@ static struct inode *relayfs_get_inode(struct super_block *sb, int mode,
  *      @name: the name of the file to create
  *      @parent: parent directory
  *      @mode: mode
- *      @chan: relay channel associated with the file
+ *      @fops: file operations to use for the file
+ *      @data: user-associated data for this file
  *
  *      Returns the new dentry, NULL on failure
  *
@@ -92,7 +85,8 @@ static struct inode *relayfs_get_inode(struct super_block *sb, int mode,
 static struct dentry *relayfs_create_entry(const char *name,
                                            struct dentry *parent,
                                            int mode,
-                                           struct rchan *chan)
+                                           struct file_operations *fops,
+                                           void *data)
 {
         struct dentry *d;
         struct inode *inode;
@@ -115,7 +109,7 @@ static struct dentry *relayfs_create_entry(const char *name,
         }
 
         parent = dget(parent);
-        down(&parent->d_inode->i_sem);
+        mutex_lock(&parent->d_inode->i_mutex);
         d = lookup_one_len(name, parent, strlen(name));
         if (IS_ERR(d)) {
                 d = NULL;
@@ -127,7 +121,7 @@ static struct dentry *relayfs_create_entry(const char *name,
                 goto release_mount;
         }
 
-        inode = relayfs_get_inode(parent->d_inode->i_sb, mode, chan);
+        inode = relayfs_get_inode(parent->d_inode->i_sb, mode, fops, data);
         if (!inode) {
                 d = NULL;
                 goto release_mount;
@@ -145,7 +139,7 @@ release_mount:
         simple_release_fs(&relayfs_mount, &relayfs_mount_count);
 
 exit:
-        up(&parent->d_inode->i_sem);
+        mutex_unlock(&parent->d_inode->i_mutex);
         dput(parent);
         return d;
 }
@@ -155,20 +149,26 @@ exit:
  *      @name: the name of the file to create
  *      @parent: parent directory
  *      @mode: mode, if not specied the default perms are used
- *      @chan: channel associated with the file
+ *      @fops: file operations to use for the file
+ *      @data: user-associated data for this file
  *
  *      Returns file dentry if successful, NULL otherwise.
  *
  *      The file will be created user r on behalf of current user.
  */
-struct dentry *relayfs_create_file(const char *name, struct dentry *parent,
-                                   int mode, struct rchan *chan)
+struct dentry *relayfs_create_file(const char *name,
+                                   struct dentry *parent,
+                                   int mode,
+                                   struct file_operations *fops,
+                                   void *data)
 {
+        BUG_ON(!fops);
+
         if (!mode)
                 mode = S_IRUSR;
         mode = (mode & S_IALLUGO) | S_IFREG;
 
-        return relayfs_create_entry(name, parent, mode, chan);
+        return relayfs_create_entry(name, parent, mode, fops, data);
 }
 
 /**
@@ -183,7 +183,7 @@ struct dentry *relayfs_create_file(const char *name, struct dentry *parent,
 struct dentry *relayfs_create_dir(const char *name, struct dentry *parent)
 {
         int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
-        return relayfs_create_entry(name, parent, mode, NULL);
+        return relayfs_create_entry(name, parent, mode, NULL, NULL);
 }
 
 /**
@@ -204,7 +204,7 @@ int relayfs_remove(struct dentry *dentry)
                 return -EINVAL;
 
         parent = dget(parent);
-        down(&parent->d_inode->i_sem);
+        mutex_lock(&parent->d_inode->i_mutex);
         if (dentry->d_inode) {
                 if (S_ISDIR(dentry->d_inode->i_mode))
                         error = simple_rmdir(parent->d_inode, dentry);
@@ -215,7 +215,7 @@ int relayfs_remove(struct dentry *dentry)
         }
         if (!error)
                 dput(dentry);
-        up(&parent->d_inode->i_sem);
+        mutex_unlock(&parent->d_inode->i_mutex);
         dput(parent);
 
         if (!error)
@@ -225,6 +225,17 @@ int relayfs_remove(struct dentry *dentry)
 }
 
 /**
+ *      relayfs_remove_file - remove a file from relay filesystem
+ *      @dentry: directory dentry
+ *
+ *      Returns 0 if successful, negative otherwise.
+ */
+int relayfs_remove_file(struct dentry *dentry)
+{
+        return relayfs_remove(dentry);
+}
+
+/**
  *      relayfs_remove_dir - remove a directory in the relay filesystem
  *      @dentry: directory dentry
  *
@@ -236,45 +247,45 @@ int relayfs_remove_dir(struct dentry *dentry)
 }
 
 /**
- *      relayfs_open - open file op for relayfs files
+ *      relay_file_open - open file op for relay files
  *      @inode: the inode
  *      @filp: the file
  *
  *      Increments the channel buffer refcount.
  */
-static int relayfs_open(struct inode *inode, struct file *filp)
+static int relay_file_open(struct inode *inode, struct file *filp)
 {
-        struct rchan_buf *buf = RELAYFS_I(inode)->buf;
+        struct rchan_buf *buf = inode->u.generic_ip;
         kref_get(&buf->kref);
+        filp->private_data = buf;
 
         return 0;
 }
 
 /**
- *      relayfs_mmap - mmap file op for relayfs files
+ *      relay_file_mmap - mmap file op for relay files
  *      @filp: the file
  *      @vma: the vma describing what to map
  *
  *      Calls upon relay_mmap_buf to map the file into user space.
  */
-static int relayfs_mmap(struct file *filp, struct vm_area_struct *vma)
+static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma)
 {
-        struct inode *inode = filp->f_dentry->d_inode;
-        return relay_mmap_buf(RELAYFS_I(inode)->buf, vma);
+        struct rchan_buf *buf = filp->private_data;
+        return relay_mmap_buf(buf, vma);
 }
 
 /**
- *      relayfs_poll - poll file op for relayfs files
+ *      relay_file_poll - poll file op for relay files
  *      @filp: the file
  *      @wait: poll table
  *
  *      Poll implemention.
  */
-static unsigned int relayfs_poll(struct file *filp, poll_table *wait)
+static unsigned int relay_file_poll(struct file *filp, poll_table *wait)
 {
         unsigned int mask = 0;
-        struct inode *inode = filp->f_dentry->d_inode;
-        struct rchan_buf *buf = RELAYFS_I(inode)->buf;
+        struct rchan_buf *buf = filp->private_data;
 
         if (buf->finalized)
                 return POLLERR;
@@ -289,27 +300,27 @@ static unsigned int relayfs_poll(struct file *filp, poll_table *wait)
 }
 
 /**
- *      relayfs_release - release file op for relayfs files
+ *      relay_file_release - release file op for relay files
  *      @inode: the inode
  *      @filp: the file
  *
  *      Decrements the channel refcount, as the filesystem is
  *      no longer using it.
  */
-static int relayfs_release(struct inode *inode, struct file *filp)
+static int relay_file_release(struct inode *inode, struct file *filp)
 {
-        struct rchan_buf *buf = RELAYFS_I(inode)->buf;
+        struct rchan_buf *buf = filp->private_data;
         kref_put(&buf->kref, relay_remove_buf);
 
         return 0;
 }
 
 /**
- *      relayfs_read_consume - update the consumed count for the buffer
+ *      relay_file_read_consume - update the consumed count for the buffer
  */
-static void relayfs_read_consume(struct rchan_buf *buf,
-                                 size_t read_pos,
-                                 size_t bytes_consumed)
+static void relay_file_read_consume(struct rchan_buf *buf,
+                                    size_t read_pos,
+                                    size_t bytes_consumed)
 {
         size_t subbuf_size = buf->chan->subbuf_size;
         size_t n_subbufs = buf->chan->n_subbufs;
@@ -332,9 +343,9 @@ static void relayfs_read_consume(struct rchan_buf *buf,
 }
 
 /**
- *      relayfs_read_avail - boolean, are there unconsumed bytes available?
+ *      relay_file_read_avail - boolean, are there unconsumed bytes available?
  */
-static int relayfs_read_avail(struct rchan_buf *buf, size_t read_pos)
+static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
 {
         size_t bytes_produced, bytes_consumed, write_offset;
         size_t subbuf_size = buf->chan->subbuf_size;
@@ -365,16 +376,16 @@ static int relayfs_read_avail(struct rchan_buf *buf, size_t read_pos)
         if (bytes_produced == bytes_consumed)
                 return 0;
 
-        relayfs_read_consume(buf, read_pos, 0);
+        relay_file_read_consume(buf, read_pos, 0);
 
         return 1;
 }
 
 /**
- *      relayfs_read_subbuf_avail - return bytes available in sub-buffer
+ *      relay_file_read_subbuf_avail - return bytes available in sub-buffer
  */
-static size_t relayfs_read_subbuf_avail(size_t read_pos,
-                                        struct rchan_buf *buf)
+static size_t relay_file_read_subbuf_avail(size_t read_pos,
+                                           struct rchan_buf *buf)
 {
         size_t padding, avail = 0;
         size_t read_subbuf, read_offset, write_subbuf, write_offset;
@@ -396,14 +407,14 @@ static size_t relayfs_read_subbuf_avail(size_t read_pos,
 }
 
 /**
- *      relayfs_read_start_pos - find the first available byte to read
+ *      relay_file_read_start_pos - find the first available byte to read
  *
  *      If the read_pos is in the middle of padding, return the
  *      position of the first actually available byte, otherwise
  *      return the original value.
  */
-static size_t relayfs_read_start_pos(size_t read_pos,
-                                     struct rchan_buf *buf)
+static size_t relay_file_read_start_pos(size_t read_pos,
+                                        struct rchan_buf *buf)
 {
         size_t read_subbuf, padding, padding_start, padding_end;
         size_t subbuf_size = buf->chan->subbuf_size;
@@ -422,11 +433,11 @@ static size_t relayfs_read_start_pos(size_t read_pos,
 }
 
 /**
- *      relayfs_read_end_pos - return the new read position
+ *      relay_file_read_end_pos - return the new read position
  */
-static size_t relayfs_read_end_pos(struct rchan_buf *buf,
-                                   size_t read_pos,
-                                   size_t count)
+static size_t relay_file_read_end_pos(struct rchan_buf *buf,
+                                      size_t read_pos,
+                                      size_t count)
 {
         size_t read_subbuf, padding, end_pos;
         size_t subbuf_size = buf->chan->subbuf_size;
@@ -445,7 +456,7 @@ static size_t relayfs_read_end_pos(struct rchan_buf *buf,
 }
 
 /**
- *      relayfs_read - read file op for relayfs files
+ *      relay_file_read - read file op for relay files
  *      @filp: the file
  *      @buffer: the userspace buffer
  *      @count: number of bytes to read
@@ -454,23 +465,23 @@ static size_t relayfs_read_end_pos(struct rchan_buf *buf,
  *      Reads count bytes or the number of bytes available in the
  *      current sub-buffer being read, whichever is smaller.
  */
-static ssize_t relayfs_read(struct file *filp,
-                            char __user *buffer,
-                            size_t count,
-                            loff_t *ppos)
+static ssize_t relay_file_read(struct file *filp,
+                               char __user *buffer,
+                               size_t count,
+                               loff_t *ppos)
 {
+        struct rchan_buf *buf = filp->private_data;
         struct inode *inode = filp->f_dentry->d_inode;
-        struct rchan_buf *buf = RELAYFS_I(inode)->buf;
         size_t read_start, avail;
         ssize_t ret = 0;
         void *from;
 
-        down(&inode->i_sem);
-        if(!relayfs_read_avail(buf, *ppos))
+        mutex_lock(&inode->i_mutex);
+        if(!relay_file_read_avail(buf, *ppos))
                 goto out;
 
-        read_start = relayfs_read_start_pos(*ppos, buf);
-        avail = relayfs_read_subbuf_avail(read_start, buf);
+        read_start = relay_file_read_start_pos(*ppos, buf);
+        avail = relay_file_read_subbuf_avail(read_start, buf);
         if (!avail)
                 goto out;
 
@@ -480,58 +491,25 @@ static ssize_t relayfs_read(struct file *filp,
                 ret = -EFAULT;
                 goto out;
         }
-        relayfs_read_consume(buf, read_start, count);
-        *ppos = relayfs_read_end_pos(buf, read_start, count);
+        relay_file_read_consume(buf, read_start, count);
+        *ppos = relay_file_read_end_pos(buf, read_start, count);
 out:
-        up(&inode->i_sem);
+        mutex_unlock(&inode->i_mutex);
         return ret;
 }
 
-/**
- *      relayfs alloc_inode() implementation
- */
-static struct inode *relayfs_alloc_inode(struct super_block *sb)
-{
-        struct relayfs_inode_info *p = kmem_cache_alloc(relayfs_inode_cachep, SLAB_KERNEL);
-        if (!p)
-                return NULL;
-        p->buf = NULL;
-
-        return &p->vfs_inode;
-}
-
-/**
- *      relayfs destroy_inode() implementation
- */
-static void relayfs_destroy_inode(struct inode *inode)
-{
-        if (RELAYFS_I(inode)->buf)
-                relay_destroy_buf(RELAYFS_I(inode)->buf);
-
-        kmem_cache_free(relayfs_inode_cachep, RELAYFS_I(inode));
-}
-
-static void init_once(void *p, kmem_cache_t *cachep, unsigned long flags)
-{
-        struct relayfs_inode_info *i = p;
-        if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR)
-                inode_init_once(&i->vfs_inode);
-}
-
-struct file_operations relayfs_file_operations = {
-        .open           = relayfs_open,
-        .poll           = relayfs_poll,
-        .mmap           = relayfs_mmap,
-        .read           = relayfs_read,
+struct file_operations relay_file_operations = {
+        .open           = relay_file_open,
+        .poll           = relay_file_poll,
+        .mmap           = relay_file_mmap,
+        .read           = relay_file_read,
         .llseek         = no_llseek,
-        .release        = relayfs_release,
+        .release        = relay_file_release,
 };
 
 static struct super_operations relayfs_ops = {
         .statfs         = simple_statfs,
         .drop_inode     = generic_delete_inode,
-        .alloc_inode    = relayfs_alloc_inode,
-        .destroy_inode  = relayfs_destroy_inode,
 };
 
 static int relayfs_fill_super(struct super_block * sb, void * data, int silent)
@@ -544,7 +522,7 @@ static int relayfs_fill_super(struct super_block * sb, void * data, int silent)
         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
         sb->s_magic = RELAYFS_MAGIC;
         sb->s_op = &relayfs_ops;
-        inode = relayfs_get_inode(sb, mode, NULL);
+        inode = relayfs_get_inode(sb, mode, NULL, NULL);
 
         if (!inode)
                 return -ENOMEM;
@@ -575,33 +553,27 @@ static struct file_system_type relayfs_fs_type = {
 
 static int __init init_relayfs_fs(void)
 {
-        int err;
-
-        relayfs_inode_cachep = kmem_cache_create("relayfs_inode_cache",
-                                sizeof(struct relayfs_inode_info), 0,
-                                0, init_once, NULL);
-        if (!relayfs_inode_cachep)
-                return -ENOMEM;
-
-        err = register_filesystem(&relayfs_fs_type);
-        if (err)
-                kmem_cache_destroy(relayfs_inode_cachep);
-
-        return err;
+        return register_filesystem(&relayfs_fs_type);
 }
 
 static void __exit exit_relayfs_fs(void)
 {
+
+
+
+
+
         unregister_filesystem(&relayfs_fs_type);
-        kmem_cache_destroy(relayfs_inode_cachep);
 }
 
 module_init(init_relayfs_fs)
 module_exit(exit_relayfs_fs)
 
-EXPORT_SYMBOL_GPL(relayfs_file_operations);
+EXPORT_SYMBOL_GPL(relay_file_operations);
 EXPORT_SYMBOL_GPL(relayfs_create_dir);
 EXPORT_SYMBOL_GPL(relayfs_remove_dir);
+EXPORT_SYMBOL_GPL(relayfs_create_file);
+EXPORT_SYMBOL_GPL(relayfs_remove_file);
 
 MODULE_AUTHOR("Tom Zanussi <zanussi@us.ibm.com> and Karim Yaghmour <karim@opersys.com>");
 MODULE_DESCRIPTION("Relay Filesystem");
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];
         }
 }
 
diff --git a/fs/relayfs/relay.h b/fs/relayfs/relay.h
index 703503fa22b6..0993d3e5753b 100644
--- a/fs/relayfs/relay.h
+++ b/fs/relayfs/relay.h
@@ -1,10 +1,6 @@
 #ifndef _RELAY_H
 #define _RELAY_H
 
-struct dentry *relayfs_create_file(const char *name,
-                                   struct dentry *parent,
-                                   int mode,
-                                   struct rchan *chan);
 extern int relayfs_remove(struct dentry *dentry);
 extern int relay_buf_empty(struct rchan_buf *buf);
 extern void relay_destroy_channel(struct kref *kref);