SUNRPC: Add an rpc_pipefs front end for the sunrpc cache code

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

4 files changed, 190 insertions, 0 deletions

diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index 8e5bf3036652..6f52b4d7c447 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -64,6 +64,10 @@ struct cache_detail_procfs {
         struct proc_dir_entry   *flush_ent, *channel_ent, *content_ent;
 };
 
+struct cache_detail_pipefs {
+        struct dentry *dir;
+};
+
 struct cache_detail {
         struct module *         owner;
         int                     hash_size;
@@ -110,6 +114,7 @@ struct cache_detail {
 
         union {
                 struct cache_detail_procfs procfs;
+                struct cache_detail_pipefs pipefs;
         } u;
 };
 
@@ -135,6 +140,10 @@ struct cache_deferred_req {
 };
 
 
+extern const struct file_operations cache_file_operations_pipefs;
+extern const struct file_operations content_file_operations_pipefs;
+extern const struct file_operations cache_flush_operations_pipefs;
+
 extern struct cache_head *
 sunrpc_cache_lookup(struct cache_detail *detail,
                     struct cache_head *key, int hash);
@@ -186,6 +195,10 @@ extern void cache_purge(struct cache_detail *detail);
 extern int cache_register(struct cache_detail *cd);
 extern void cache_unregister(struct cache_detail *cd);
 
+extern int sunrpc_cache_register_pipefs(struct dentry *parent, const char *,
+                                        mode_t, struct cache_detail *);
+extern void sunrpc_cache_unregister_pipefs(struct cache_detail *);
+
 extern void qword_add(char **bpp, int *lp, char *str);
 extern void qword_addhex(char **bpp, int *lp, char *buf, int blen);
 extern int qword_get(char **bpp, char *dest, int bufsize);
diff --git a/include/linux/sunrpc/rpc_pipe_fs.h b/include/linux/sunrpc/rpc_pipe_fs.h
index 88332ef1e959..a92571a34556 100644
--- a/include/linux/sunrpc/rpc_pipe_fs.h
+++ b/include/linux/sunrpc/rpc_pipe_fs.h
@@ -47,6 +47,14 @@ extern int rpc_queue_upcall(struct inode *, struct rpc_pipe_msg *);
 struct rpc_clnt;
 extern struct dentry *rpc_create_client_dir(struct dentry *, struct qstr *, struct rpc_clnt *);
 extern int rpc_remove_client_dir(struct dentry *);
+
+struct cache_detail;
+extern struct dentry *rpc_create_cache_dir(struct dentry *,
+                                           struct qstr *,
+                                           mode_t umode,
+                                           struct cache_detail *);
+extern void rpc_remove_cache_dir(struct dentry *);
+
 extern struct dentry *rpc_mkpipe(struct dentry *, const char *, void *,
                                  const struct rpc_pipe_ops *, int flags);
 extern int rpc_unlink(struct dentry *);
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 1cd82eda56d0..db7720e453c3 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -32,6 +32,7 @@
 #include <linux/sunrpc/types.h>
 #include <linux/sunrpc/cache.h>
 #include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
 
 #define  RPCDBG_FACILITY RPCDBG_CACHE
 
@@ -1438,3 +1439,128 @@ void cache_unregister(struct cache_detail *cd)
         sunrpc_destroy_cache_detail(cd);
 }
 EXPORT_SYMBOL_GPL(cache_unregister);
+
+static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
+                                 size_t count, loff_t *ppos)
+{
+        struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
+
+        return cache_read(filp, buf, count, ppos, cd);
+}
+
+static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
+                                  size_t count, loff_t *ppos)
+{
+        struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
+
+        return cache_write(filp, buf, count, ppos, cd);
+}
+
+static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait)
+{
+        struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
+
+        return cache_poll(filp, wait, cd);
+}
+
+static int cache_ioctl_pipefs(struct inode *inode, struct file *filp,
+                              unsigned int cmd, unsigned long arg)
+{
+        struct cache_detail *cd = RPC_I(inode)->private;
+
+        return cache_ioctl(inode, filp, cmd, arg, cd);
+}
+
+static int cache_open_pipefs(struct inode *inode, struct file *filp)
+{
+        struct cache_detail *cd = RPC_I(inode)->private;
+
+        return cache_open(inode, filp, cd);
+}
+
+static int cache_release_pipefs(struct inode *inode, struct file *filp)
+{
+        struct cache_detail *cd = RPC_I(inode)->private;
+
+        return cache_release(inode, filp, cd);
+}
+
+const struct file_operations cache_file_operations_pipefs = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .read           = cache_read_pipefs,
+        .write          = cache_write_pipefs,
+        .poll           = cache_poll_pipefs,
+        .ioctl          = cache_ioctl_pipefs, /* for FIONREAD */
+        .open           = cache_open_pipefs,
+        .release        = cache_release_pipefs,
+};
+
+static int content_open_pipefs(struct inode *inode, struct file *filp)
+{
+        struct cache_detail *cd = RPC_I(inode)->private;
+
+        return content_open(inode, filp, cd);
+}
+
+const struct file_operations content_file_operations_pipefs = {
+        .open           = content_open_pipefs,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release_private,
+};
+
+static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
+                            size_t count, loff_t *ppos)
+{
+        struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
+
+        return read_flush(filp, buf, count, ppos, cd);
+}
+
+static ssize_t write_flush_pipefs(struct file *filp,
+                                  const char __user *buf,
+                                  size_t count, loff_t *ppos)
+{
+        struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
+
+        return write_flush(filp, buf, count, ppos, cd);
+}
+
+const struct file_operations cache_flush_operations_pipefs = {
+        .open           = nonseekable_open,
+        .read           = read_flush_pipefs,
+        .write          = write_flush_pipefs,
+};
+
+int sunrpc_cache_register_pipefs(struct dentry *parent,
+                                 const char *name, mode_t umode,
+                                 struct cache_detail *cd)
+{
+        struct qstr q;
+        struct dentry *dir;
+        int ret = 0;
+
+        sunrpc_init_cache_detail(cd);
+        q.name = name;
+        q.len = strlen(name);
+        q.hash = full_name_hash(q.name, q.len);
+        dir = rpc_create_cache_dir(parent, &q, umode, cd);
+        if (!IS_ERR(dir))
+                cd->u.pipefs.dir = dir;
+        else {
+                sunrpc_destroy_cache_detail(cd);
+                ret = PTR_ERR(dir);
+        }
+        return ret;
+}
+EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
+
+void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
+{
+        rpc_remove_cache_dir(cd->u.pipefs.dir);
+        cd->u.pipefs.dir = NULL;
+        sunrpc_destroy_cache_detail(cd);
+}
+EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
+
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 57e9cd3c49b6..8dd81535e08f 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -26,6 +26,7 @@
 #include <linux/sunrpc/clnt.h>
 #include <linux/workqueue.h>
 #include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/sunrpc/cache.h>
 
 static struct vfsmount *rpc_mount __read_mostly;
 static int rpc_mount_count;
@@ -882,6 +883,48 @@ int rpc_remove_client_dir(struct dentry *dentry)
         return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
 }
 
+static const struct rpc_filelist cache_pipefs_files[3] = {
+        [0] = {
+                .name = "channel",
+                .i_fop = &cache_file_operations_pipefs,
+                .mode = S_IFIFO|S_IRUSR|S_IWUSR,
+        },
+        [1] = {
+                .name = "content",
+                .i_fop = &content_file_operations_pipefs,
+                .mode = S_IFREG|S_IRUSR,
+        },
+        [2] = {
+                .name = "flush",
+                .i_fop = &cache_flush_operations_pipefs,
+                .mode = S_IFREG|S_IRUSR|S_IWUSR,
+        },
+};
+
+static int rpc_cachedir_populate(struct dentry *dentry, void *private)
+{
+        return rpc_populate(dentry,
+                            cache_pipefs_files, 0, 3,
+                            private);
+}
+
+static void rpc_cachedir_depopulate(struct dentry *dentry)
+{
+        rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
+}
+
+struct dentry *rpc_create_cache_dir(struct dentry *parent, struct qstr *name,
+                                    mode_t umode, struct cache_detail *cd)
+{
+        return rpc_mkdir_populate(parent, name, umode, NULL,
+                        rpc_cachedir_populate, cd);
+}
+
+void rpc_remove_cache_dir(struct dentry *dentry)
+{
+        rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
+}
+
 /*
  * populate the filesystem
  */