Merge branch 'topic/core-cleanup' into for-linus
[safe/jmp/linux-2.6] / fs / 9p / v9fs.c
index 873802d..f8b86e9 100644 (file)
@@ -3,7 +3,7 @@
  *
  *  This file contains functions assisting in mapping VFS to 9P2000
  *
- *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  *
  *  This program is free software; you can redistribute it and/or modify
 #include <linux/sched.h>
 #include <linux/parser.h>
 #include <linux/idr.h>
+#include <linux/slab.h>
 #include <net/9p/9p.h>
-#include <net/9p/transport.h>
-#include <net/9p/conn.h>
 #include <net/9p/client.h>
+#include <net/9p/transport.h>
 #include "v9fs.h"
 #include "v9fs_vfs.h"
+#include "cache.h"
+
+static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
+static LIST_HEAD(v9fs_sessionlist);
 
 /*
 * Option Parsing (code inspired by NFS code)
 *  NOTE: each transport will parse its own options
 */
+ * Option Parsing (code inspired by NFS code)
+ *  NOTE: each transport will parse its own options
+ */
 
 enum {
        /* Options that take integer arguments */
-       Opt_debug, Opt_msize, Opt_dfltuid, Opt_dfltgid, Opt_afid,
+       Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
        /* String options */
-       Opt_uname, Opt_remotename, Opt_trans,
+       Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag,
        /* Options that take no arguments */
-       Opt_legacy, Opt_nodevmap,
+       Opt_nodevmap,
        /* Cache options */
-       Opt_cache_loose,
+       Opt_cache_loose, Opt_fscache,
        /* Access options */
        Opt_access,
        /* Error token */
        Opt_err
 };
 
-static match_table_t tokens = {
+static const match_table_t tokens = {
        {Opt_debug, "debug=%x"},
-       {Opt_msize, "msize=%u"},
        {Opt_dfltuid, "dfltuid=%u"},
        {Opt_dfltgid, "dfltgid=%u"},
        {Opt_afid, "afid=%u"},
        {Opt_uname, "uname=%s"},
        {Opt_remotename, "aname=%s"},
-       {Opt_trans, "trans=%s"},
-       {Opt_legacy, "noextend"},
        {Opt_nodevmap, "nodevmap"},
-       {Opt_cache_loose, "cache=loose"},
+       {Opt_cache, "cache=%s"},
        {Opt_cache_loose, "loose"},
+       {Opt_fscache, "fscache"},
+       {Opt_cachetag, "cachetag=%s"},
        {Opt_access, "access=%s"},
        {Opt_err, NULL}
 };
 
 /**
  * v9fs_parse_options - parse mount options into session structure
- * @options: options string passed from mount
  * @v9ses: existing v9fs session information
  *
+ * Return 0 upon success, -ERRNO upon failure.
  */
 
-static void v9fs_parse_options(struct v9fs_session_info *v9ses)
+static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 {
-       char *options = v9ses->options;
+       char *options, *tmp_options;
        substring_t args[MAX_OPT_ARGS];
        char *p;
-       int option;
-       int ret;
+       int option = 0;
        char *s, *e;
+       int ret = 0;
 
        /* setup defaults */
-       v9ses->maxdata = 8192;
        v9ses->afid = ~0;
        v9ses->debug = 0;
        v9ses->cache = 0;
-       v9ses->trans = v9fs_default_trans();
+#ifdef CONFIG_9P_FSCACHE
+       v9ses->cachetag = NULL;
+#endif
+
+       if (!opts)
+               return 0;
 
-       if (!options)
-               return;
+       tmp_options = kstrdup(opts, GFP_KERNEL);
+       if (!tmp_options) {
+               ret = -ENOMEM;
+               goto fail_option_alloc;
+       }
+       options = tmp_options;
 
        while ((p = strsep(&options, ",")) != NULL) {
                int token;
@@ -105,9 +116,11 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
                        continue;
                token = match_token(p, tokens, args);
                if (token < Opt_uname) {
-                       if ((ret = match_int(&args[0], &option)) < 0) {
+                       int r = match_int(&args[0], &option);
+                       if (r < 0) {
                                P9_DPRINTK(P9_DEBUG_ERROR,
                                        "integer field, but no integer?\n");
+                               ret = r;
                                continue;
                        }
                }
@@ -118,9 +131,7 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
                        p9_debug_level = option;
 #endif
                        break;
-               case Opt_msize:
-                       v9ses->maxdata = option;
-                       break;
+
                case Opt_dfltuid:
                        v9ses->dfltuid = option;
                        break;
@@ -130,17 +141,11 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
                case Opt_afid:
                        v9ses->afid = option;
                        break;
-               case Opt_trans:
-                       v9ses->trans = v9fs_match_trans(&args[0]);
-                       break;
                case Opt_uname:
-                       match_strcpy(v9ses->uname, &args[0]);
+                       match_strlcpy(v9ses->uname, &args[0], PATH_MAX);
                        break;
                case Opt_remotename:
-                       match_strcpy(v9ses->aname, &args[0]);
-                       break;
-               case Opt_legacy:
-                       v9ses->flags &= ~V9FS_EXTENDED;
+                       match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
                        break;
                case Opt_nodevmap:
                        v9ses->nodev = 1;
@@ -148,9 +153,41 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
                case Opt_cache_loose:
                        v9ses->cache = CACHE_LOOSE;
                        break;
+               case Opt_fscache:
+                       v9ses->cache = CACHE_FSCACHE;
+                       break;
+               case Opt_cachetag:
+#ifdef CONFIG_9P_FSCACHE
+                       v9ses->cachetag = match_strdup(&args[0]);
+#endif
+                       break;
+               case Opt_cache:
+                       s = match_strdup(&args[0]);
+                       if (!s) {
+                               ret = -ENOMEM;
+                               P9_DPRINTK(P9_DEBUG_ERROR,
+                                 "problem allocating copy of cache arg\n");
+                               goto free_and_return;
+                       }
+
+                       if (strcmp(s, "loose") == 0)
+                               v9ses->cache = CACHE_LOOSE;
+                       else if (strcmp(s, "fscache") == 0)
+                               v9ses->cache = CACHE_FSCACHE;
+                       else
+                               v9ses->cache = CACHE_NONE;
+                       kfree(s);
+                       break;
 
                case Opt_access:
                        s = match_strdup(&args[0]);
+                       if (!s) {
+                               ret = -ENOMEM;
+                               P9_DPRINTK(P9_DEBUG_ERROR,
+                                 "problem allocating copy of access arg\n");
+                               goto free_and_return;
+                       }
+
                        v9ses->flags &= ~V9FS_ACCESS_MASK;
                        if (strcmp(s, "user") == 0)
                                v9ses->flags |= V9FS_ACCESS_USER;
@@ -158,16 +195,22 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
                                v9ses->flags |= V9FS_ACCESS_ANY;
                        else {
                                v9ses->flags |= V9FS_ACCESS_SINGLE;
-                               v9ses->uid = simple_strtol(s, &e, 10);
+                               v9ses->uid = simple_strtoul(s, &e, 10);
                                if (*e != '\0')
                                        v9ses->uid = ~0;
                        }
+                       kfree(s);
                        break;
 
                default:
                        continue;
                }
        }
+
+free_and_return:
+       kfree(tmp_options);
+fail_option_alloc:
+       return ret;
 }
 
 /**
@@ -182,8 +225,8 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
                  const char *dev_name, char *data)
 {
        int retval = -EINVAL;
-       struct p9_trans *trans = NULL;
        struct p9_fid *fid;
+       int rc;
 
        v9ses->uname = __getname();
        if (!v9ses->uname)
@@ -195,34 +238,31 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
                return ERR_PTR(-ENOMEM);
        }
 
-       v9ses->flags = V9FS_EXTENDED | V9FS_ACCESS_USER;
+       rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY);
+       if (rc) {
+               __putname(v9ses->aname);
+               __putname(v9ses->uname);
+               return ERR_PTR(rc);
+       }
+
+       spin_lock(&v9fs_sessionlist_lock);
+       list_add(&v9ses->slist, &v9fs_sessionlist);
+       spin_unlock(&v9fs_sessionlist_lock);
+
+       v9ses->flags = V9FS_ACCESS_USER;
        strcpy(v9ses->uname, V9FS_DEFUSER);
        strcpy(v9ses->aname, V9FS_DEFANAME);
        v9ses->uid = ~0;
        v9ses->dfltuid = V9FS_DEFUID;
        v9ses->dfltgid = V9FS_DEFGID;
-       v9ses->options = kstrdup(data, GFP_KERNEL);
-       v9fs_parse_options(v9ses);
-
-       if (v9ses->trans == NULL) {
-               retval = -EPROTONOSUPPORT;
-               P9_DPRINTK(P9_DEBUG_ERROR,
-                               "No transport defined or default transport\n");
-               goto error;
-       }
 
-       trans = v9ses->trans->create(dev_name, v9ses->options);
-       if (IS_ERR(trans)) {
-               retval = PTR_ERR(trans);
-               trans = NULL;
+       rc = v9fs_parse_options(v9ses, data);
+       if (rc < 0) {
+               retval = rc;
                goto error;
        }
-       if ((v9ses->maxdata+P9_IOHDRSZ) > v9ses->trans->maxsize)
-               v9ses->maxdata = v9ses->trans->maxsize-P9_IOHDRSZ;
-
-       v9ses->clnt = p9_client_create(trans, v9ses->maxdata+P9_IOHDRSZ,
-               v9fs_extended(v9ses));
 
+       v9ses->clnt = p9_client_create(dev_name, data);
        if (IS_ERR(v9ses->clnt)) {
                retval = PTR_ERR(v9ses->clnt);
                v9ses->clnt = NULL;
@@ -230,11 +270,15 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
                goto error;
        }
 
-       if (!v9ses->clnt->dotu)
-               v9ses->flags &= ~V9FS_EXTENDED;
+       if (p9_is_proto_dotl(v9ses->clnt))
+               v9ses->flags |= V9FS_PROTO_2000L;
+       else if (p9_is_proto_dotu(v9ses->clnt))
+               v9ses->flags |= V9FS_PROTO_2000U;
+
+       v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 
        /* for legacy mode, fall back to V9FS_ACCESS_ANY */
-       if (!v9fs_extended(v9ses) &&
+       if (!v9fs_proto_dotu(v9ses) &&
                ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
 
                v9ses->flags &= ~V9FS_ACCESS_MASK;
@@ -256,10 +300,15 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
        else
                fid->uid = ~0;
 
+#ifdef CONFIG_9P_FSCACHE
+       /* register the session for caching */
+       v9fs_cache_session_get_cookie(v9ses);
+#endif
+
        return fid;
 
 error:
-       v9fs_session_close(v9ses);
+       bdi_destroy(&v9ses->bdi);
        return ERR_PTR(retval);
 }
 
@@ -276,41 +325,175 @@ void v9fs_session_close(struct v9fs_session_info *v9ses)
                v9ses->clnt = NULL;
        }
 
+#ifdef CONFIG_9P_FSCACHE
+       if (v9ses->fscache) {
+               v9fs_cache_session_put_cookie(v9ses);
+               kfree(v9ses->cachetag);
+       }
+#endif
        __putname(v9ses->uname);
        __putname(v9ses->aname);
-       kfree(v9ses->options);
+
+       bdi_destroy(&v9ses->bdi);
+
+       spin_lock(&v9fs_sessionlist_lock);
+       list_del(&v9ses->slist);
+       spin_unlock(&v9fs_sessionlist_lock);
 }
 
 /**
- * v9fs_session_cancel - mark transport as disconnected
- *     and cancel all pending requests.
+ * v9fs_session_cancel - terminate a session
+ * @v9ses: session to terminate
+ *
+ * mark transport as disconnected and cancel all pending requests.
  */
+
 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
        P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
        p9_client_disconnect(v9ses->clnt);
 }
 
+/**
+ * v9fs_session_begin_cancel - Begin terminate of a session
+ * @v9ses: session to terminate
+ *
+ * After this call we don't allow any request other than clunk.
+ */
+
+void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
+{
+       P9_DPRINTK(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
+       p9_client_begin_disconnect(v9ses->clnt);
+}
+
 extern int v9fs_error_init(void);
 
+static struct kobject *v9fs_kobj;
+
+#ifdef CONFIG_9P_FSCACHE
+/**
+ * caches_show - list caches associated with a session
+ *
+ * Returns the size of buffer written.
+ */
+
+static ssize_t caches_show(struct kobject *kobj,
+                          struct kobj_attribute *attr,
+                          char *buf)
+{
+       ssize_t n = 0, count = 0, limit = PAGE_SIZE;
+       struct v9fs_session_info *v9ses;
+
+       spin_lock(&v9fs_sessionlist_lock);
+       list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
+               if (v9ses->cachetag) {
+                       n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
+                       if (n < 0) {
+                               count = n;
+                               break;
+                       }
+
+                       count += n;
+                       limit -= n;
+               }
+       }
+
+       spin_unlock(&v9fs_sessionlist_lock);
+       return count;
+}
+
+static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
+#endif /* CONFIG_9P_FSCACHE */
+
+static struct attribute *v9fs_attrs[] = {
+#ifdef CONFIG_9P_FSCACHE
+       &v9fs_attr_cache.attr,
+#endif
+       NULL,
+};
+
+static struct attribute_group v9fs_attr_group = {
+       .attrs = v9fs_attrs,
+};
+
+/**
+ * v9fs_sysfs_init - Initialize the v9fs sysfs interface
+ *
+ */
+
+static int v9fs_sysfs_init(void)
+{
+       v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
+       if (!v9fs_kobj)
+               return -ENOMEM;
+
+       if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
+               kobject_put(v9fs_kobj);
+               return -ENOMEM;
+       }
+
+       return 0;
+}
+
 /**
- * v9fs_init - Initialize module
+ * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
+ *
+ */
+
+static void v9fs_sysfs_cleanup(void)
+{
+       sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
+       kobject_put(v9fs_kobj);
+}
+
+/**
+ * init_v9fs - Initialize module
  *
  */
 
 static int __init init_v9fs(void)
 {
+       int err;
        printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
        /* TODO: Setup list of registered trasnport modules */
-       return register_filesystem(&v9fs_fs_type);
+       err = register_filesystem(&v9fs_fs_type);
+       if (err < 0) {
+               printk(KERN_ERR "Failed to register filesystem\n");
+               return err;
+       }
+
+       err = v9fs_cache_register();
+       if (err < 0) {
+               printk(KERN_ERR "Failed to register v9fs for caching\n");
+               goto out_fs_unreg;
+       }
+
+       err = v9fs_sysfs_init();
+       if (err < 0) {
+               printk(KERN_ERR "Failed to register with sysfs\n");
+               goto out_sysfs_cleanup;
+       }
+
+       return 0;
+
+out_sysfs_cleanup:
+       v9fs_sysfs_cleanup();
+
+out_fs_unreg:
+       unregister_filesystem(&v9fs_fs_type);
+
+       return err;
 }
 
 /**
- * v9fs_init - shutdown module
+ * exit_v9fs - shutdown module
  *
  */
 
 static void __exit exit_v9fs(void)
 {
+       v9fs_sysfs_cleanup();
+       v9fs_cache_unregister();
        unregister_filesystem(&v9fs_fs_type);
 }