[PATCH] relayfs: export relayfs_create_file() with fileops param

This patch adds a mandatory fileops param to relayfs_create_file() and exports
that function so that clients can use it to create files defined by their own
set of file operations, in relayfs.  The purpose is to allow relayfs
applications to create their own set of 'control' files alongside their relay
files in relayfs rather than having to create them in /proc or debugfs for
instance.  relayfs_create_file() is also used by relay_open_buf() to create
the relay files for a channel.  In this case, a pointer to
relayfs_file_operations is passed in, along with a pointer to the buffer
associated with the file.

Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/relayfs/inode.c b/fs/relayfs/inode.c
index 379e07cd2b34c3583daa8c004416d60c08f13932..a5e6d4f2efb9bded20601c4b94841bc2bd0ae369 100644 (file)
--- a/fs/relayfs/inode.c
+++ b/fs/relayfs/inode.c
@@ -33,7 +33,9 @@ static struct backing_dev_info                relayfs_backing_dev_info = {
        .capabilities   = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
 };
 
-static struct inode *relayfs_get_inode(struct super_block *sb, int mode,
+static struct inode *relayfs_get_inode(struct super_block *sb,
+                                      int mode,
+                                      struct file_operations *fops,
                                       void *data)
 {
        struct inode *inode;
@@ -51,8 +53,8 @@ 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 = data;
+               inode->i_fop = fops;
+               RELAYFS_I(inode)->data = data;
                break;
        case S_IFDIR:
                inode->i_op = &simple_dir_inode_operations;
@@ -73,6 +75,7 @@ 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
+ *     @fops: file operations to use for the file
  *     @data: user-associated data for this file
  *
  *     Returns the new dentry, NULL on failure
@@ -82,6 +85,7 @@ 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 file_operations *fops,
                                           void *data)
 {
        struct dentry *d;
@@ -117,7 +121,7 @@ static struct dentry *relayfs_create_entry(const char *name,
                goto release_mount;
        }
 
-       inode = relayfs_get_inode(parent->d_inode->i_sb, mode, data);
+       inode = relayfs_get_inode(parent->d_inode->i_sb, mode, fops, data);
        if (!inode) {
                d = NULL;
                goto release_mount;
@@ -145,20 +149,26 @@ exit:
  *     @name: the name of the file to create
  *     @parent: parent directory
  *     @mode: mode, if not specied the default perms are used
+ *     @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, void *data)
+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, data);
+       return relayfs_create_entry(name, parent, mode, fops, data);
 }
 
 /**
@@ -173,7 +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);
 }
 
 /**
@@ -234,7 +244,7 @@ int relayfs_remove_dir(struct dentry *dentry)
  */
 static int relayfs_open(struct inode *inode, struct file *filp)
 {
-       struct rchan_buf *buf = RELAYFS_I(inode)->buf;
+       struct rchan_buf *buf = RELAYFS_I(inode)->data;
        kref_get(&buf->kref);
 
        return 0;
@@ -250,7 +260,7 @@ static int relayfs_open(struct inode *inode, struct file *filp)
 static int relayfs_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);
+       return relay_mmap_buf(RELAYFS_I(inode)->data, vma);
 }
 
 /**
@@ -264,7 +274,7 @@ static unsigned int relayfs_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 = RELAYFS_I(inode)->data;
 
        if (buf->finalized)
                return POLLERR;
@@ -288,7 +298,7 @@ static unsigned int relayfs_poll(struct file *filp, poll_table *wait)
  */
 static int relayfs_release(struct inode *inode, struct file *filp)
 {
-       struct rchan_buf *buf = RELAYFS_I(inode)->buf;
+       struct rchan_buf *buf = RELAYFS_I(inode)->data;
        kref_put(&buf->kref, relay_remove_buf);
 
        return 0;
@@ -450,7 +460,7 @@ static ssize_t relayfs_read(struct file *filp,
                            loff_t *ppos)
 {
        struct inode *inode = filp->f_dentry->d_inode;
-       struct rchan_buf *buf = RELAYFS_I(inode)->buf;
+       struct rchan_buf *buf = RELAYFS_I(inode)->data;
        size_t read_start, avail;
        ssize_t ret = 0;
        void *from;
@@ -485,7 +495,7 @@ 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;
+       p->data = NULL;
 
        return &p->vfs_inode;
 }
@@ -531,7 +541,7 @@ 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;
@@ -589,6 +599,7 @@ module_exit(exit_relayfs_fs)
 EXPORT_SYMBOL_GPL(relayfs_file_operations);
 EXPORT_SYMBOL_GPL(relayfs_create_dir);
 EXPORT_SYMBOL_GPL(relayfs_remove_dir);
+EXPORT_SYMBOL_GPL(relayfs_create_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 7fbda177ad8fd144cc359817a483211bd90c0c45..a9cd5585c45ca33133dda7a31b64e5681d4175eb 100644 (file)
--- a/fs/relayfs/relay.c
+++ b/fs/relayfs/relay.c
@@ -176,7 +176,8 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan,
                return NULL;
 
        /* Create file in fs */
-       dentry = relayfs_create_file(filename, parent, S_IRUSR, buf);
+       dentry = relayfs_create_file(filename, parent, S_IRUSR,
+                                    &relayfs_file_operations, buf);
        if (!dentry) {
                relay_destroy_buf(buf);
                return NULL;

diff --git a/fs/relayfs/relay.h b/fs/relayfs/relay.h
index c325bb243549adf978c2f947bce741755745c285..0993d3e5753b59d172ddb2f8f67838d5766297ef 100644 (file)
--- 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,
-                                  void *data);
 extern int relayfs_remove(struct dentry *dentry);
 extern int relay_buf_empty(struct rchan_buf *buf);
 extern void relay_destroy_channel(struct kref *kref);

diff --git a/include/linux/relayfs_fs.h b/include/linux/relayfs_fs.h
index fb7e8073732583515c2b41843e1c691848cbd98e..a122df2d988079512839a2be9706f882e275d69a 100644 (file)
--- a/include/linux/relayfs_fs.h
+++ b/include/linux/relayfs_fs.h
@@ -70,7 +70,7 @@ struct rchan
 struct relayfs_inode_info
 {
        struct inode vfs_inode;
-       struct rchan_buf *buf;
+       void *data;
 };
 
 static inline struct relayfs_inode_info *RELAYFS_I(struct inode *inode)
@@ -148,6 +148,11 @@ extern size_t relay_switch_subbuf(struct rchan_buf *buf,
 extern struct dentry *relayfs_create_dir(const char *name,
                                         struct dentry *parent);
 extern int relayfs_remove_dir(struct dentry *dentry);
+extern struct dentry *relayfs_create_file(const char *name,
+                                         struct dentry *parent,
+                                         int mode,
+                                         struct file_operations *fops,
+                                         void *data);
 
 /**
  *     relay_write - write data into the channel