Merge tag '9p-for-6.19-rc1' of https://github.com/martinetd/linux

Pull 9p updates from Dominique Martinet:

- fix a bug with O_APPEND in cached mode causing data to be written
multiple times on server

- use kvmalloc for trans_fd to avoid problems with large msize and
fragmented memory This should hopefully be used in more transports
when time allows

- convert to new mount API

- minor cleanups

* tag '9p-for-6.19-rc1' of https://github.com/martinetd/linux:
9p: fix new mount API cache option handling
9p: fix cache/debug options printing in v9fs_show_options
9p: convert to the new mount API
9p: create a v9fs_context structure to hold parsed options
net/9p: move structures and macros to header files
fs/fs_parse: add back fsparam_u32hex
fs/9p: delete unnnecessary condition
fs/9p: Don't open remote file with APPEND mode when writeback cache is used
net/9p: cleanup: change p9_trans_module->def to bool
9p: Use kvmalloc for message buffers on supported transports

fs/9p/v9fs.c

···
 #include <linux/fs.h>
 #include <linux/sched.h>
 #include <linux/cred.h>
-#include <linux/parser.h>
+#include <linux/fs_parser.h>
+#include <linux/fs_context.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 #include <net/9p/9p.h>
···
  */
 
 enum {
+	/* Mount-point source, we need to handle this explicitly because
+	 * the code below accepts unknown args and the vfs layer only handles
+	 * source if we rejected it as EINVAL */
+	Opt_source,
 	/* Options that take integer arguments */
 	Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
 	/* String options */
···
 	Opt_access, Opt_posixacl,
 	/* Lock timeout option */
 	Opt_locktimeout,
-	/* Error token */
-	Opt_err
+
+	/* Client options */
+	Opt_msize, Opt_trans, Opt_legacy, Opt_version,
+
+	/* fd transport options */
+	/* Options that take integer arguments */
+	Opt_rfdno, Opt_wfdno,
+	/* Options that take no arguments */
+
+	/* rdma transport options */
+	/* Options that take integer arguments */
+	Opt_rq_depth, Opt_sq_depth, Opt_timeout,
+
+	/* Options for both fd and rdma transports */
+	Opt_port, Opt_privport,
 };
 
-static const match_table_t tokens = {
-	{Opt_debug, "debug=%x"},
-	{Opt_dfltuid, "dfltuid=%u"},
-	{Opt_dfltgid, "dfltgid=%u"},
-	{Opt_afid, "afid=%u"},
-	{Opt_uname, "uname=%s"},
-	{Opt_remotename, "aname=%s"},
-	{Opt_nodevmap, "nodevmap"},
-	{Opt_noxattr, "noxattr"},
-	{Opt_directio, "directio"},
-	{Opt_ignoreqv, "ignoreqv"},
-	{Opt_cache, "cache=%s"},
-	{Opt_cachetag, "cachetag=%s"},
-	{Opt_access, "access=%s"},
-	{Opt_posixacl, "posixacl"},
-	{Opt_locktimeout, "locktimeout=%u"},
-	{Opt_err, NULL}
+static const struct constant_table p9_versions[] = {
+	{ "9p2000",	p9_proto_legacy },
+	{ "9p2000.u",	p9_proto_2000u },
+	{ "9p2000.L",	p9_proto_2000L },
+	{}
+};
+
+/*
+ * This structure contains all parameters used for the core code,
+ * the client, and all the transports.
+ */
+const struct fs_parameter_spec v9fs_param_spec[] = {
+	fsparam_string	("source",	Opt_source),
+	fsparam_u32hex	("debug",	Opt_debug),
+	fsparam_uid	("dfltuid",	Opt_dfltuid),
+	fsparam_gid	("dfltgid",	Opt_dfltgid),
+	fsparam_u32	("afid",	Opt_afid),
+	fsparam_string	("uname",	Opt_uname),
+	fsparam_string	("aname",	Opt_remotename),
+	fsparam_flag	("nodevmap",	Opt_nodevmap),
+	fsparam_flag	("noxattr",	Opt_noxattr),
+	fsparam_flag	("directio",	Opt_directio),
+	fsparam_flag	("ignoreqv",	Opt_ignoreqv),
+	fsparam_string	("cache",	Opt_cache),
+	fsparam_string	("cachetag",	Opt_cachetag),
+	fsparam_string	("access",	Opt_access),
+	fsparam_flag	("posixacl",	Opt_posixacl),
+	fsparam_u32	("locktimeout",	Opt_locktimeout),
+
+	/* client options */
+	fsparam_u32	("msize",	Opt_msize),
+	fsparam_flag	("noextend",	Opt_legacy),
+	fsparam_string	("trans",	Opt_trans),
+	fsparam_enum	("version",	Opt_version, p9_versions),
+
+	/* fd transport options */
+	fsparam_u32	("rfdno",	Opt_rfdno),
+	fsparam_u32	("wfdno",	Opt_wfdno),
+
+	/* rdma transport options */
+	fsparam_u32	("sq",		Opt_sq_depth),
+	fsparam_u32	("rq",		Opt_rq_depth),
+	fsparam_u32	("timeout",	Opt_timeout),
+
+	/* fd and rdma transprt options */
+	fsparam_u32	("port",	Opt_port),
+	fsparam_flag	("privport",	Opt_privport),
+	{}
 };
 
 /* Interpret mount options for cache mode */
···
 	struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
 
 	if (v9ses->debug)
-		seq_printf(m, ",debug=%x", v9ses->debug);
+		seq_printf(m, ",debug=%#x", v9ses->debug);
 	if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
 		seq_printf(m, ",dfltuid=%u",
 			   from_kuid_munged(&init_user_ns, v9ses->dfltuid));
···
 	if (v9ses->nodev)
 		seq_puts(m, ",nodevmap");
 	if (v9ses->cache)
-		seq_printf(m, ",cache=%x", v9ses->cache);
+		seq_printf(m, ",cache=%#x", v9ses->cache);
 #ifdef CONFIG_9P_FSCACHE
 	if (v9ses->cachetag && (v9ses->cache & CACHE_FSCACHE))
 		seq_printf(m, ",cachetag=%s", v9ses->cachetag);
···
 }
 
 /**
- * v9fs_parse_options - parse mount options into session structure
- * @v9ses: existing v9fs session information
- * @opts: The mount option string
+ * v9fs_parse_param - parse a mount option into the filesystem context
+ * @fc: the filesystem context
+ * @param: the parameter to parse
  *
  * Return 0 upon success, -ERRNO upon failure.
  */
-
-static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
+int v9fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
-	char *options, *tmp_options;
-	substring_t args[MAX_OPT_ARGS];
-	char *p;
-	int option = 0;
+	struct v9fs_context *ctx = fc->fs_private;
+	struct fs_parse_result result;
 	char *s;
-	int ret = 0;
+	int r;
+	int opt;
+	struct p9_client_opts	*clnt = &ctx->client_opts;
+	struct p9_fd_opts	*fd_opts = &ctx->fd_opts;
+	struct p9_rdma_opts	*rdma_opts = &ctx->rdma_opts;
+	struct p9_session_opts	*session_opts = &ctx->session_opts;
 
-	/* setup defaults */
-	v9ses->afid = ~0;
-	v9ses->debug = 0;
-	v9ses->cache = CACHE_NONE;
-#ifdef CONFIG_9P_FSCACHE
-	v9ses->cachetag = NULL;
-#endif
-	v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
+	opt = fs_parse(fc, v9fs_param_spec, param, &result);
+	if (opt < 0) {
+		/*
+		 * We might like to report bad mount options here, but
+		 * traditionally 9p has ignored unknown mount options
+		 */
+		if (opt == -ENOPARAM)
+			return 0;
 
-	if (!opts)
-		return 0;
-
-	tmp_options = kstrdup(opts, GFP_KERNEL);
-	if (!tmp_options) {
-		ret = -ENOMEM;
-		goto fail_option_alloc;
+		return opt;
 	}
-	options = tmp_options;
 
-	while ((p = strsep(&options, ",")) != NULL) {
-		int token, r;
-
-		if (!*p)
-			continue;
-
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case Opt_debug:
-			r = match_int(&args[0], &option);
-			if (r < 0) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "integer field, but no integer?\n");
-				ret = r;
-			} else {
-				v9ses->debug = option;
-#ifdef CONFIG_NET_9P_DEBUG
-				p9_debug_level = option;
-#endif
-			}
-			break;
-
-		case Opt_dfltuid:
-			r = match_int(&args[0], &option);
-			if (r < 0) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "integer field, but no integer?\n");
-				ret = r;
-				continue;
-			}
-			v9ses->dfltuid = make_kuid(current_user_ns(), option);
-			if (!uid_valid(v9ses->dfltuid)) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "uid field, but not a uid?\n");
-				ret = -EINVAL;
-			}
-			break;
-		case Opt_dfltgid:
-			r = match_int(&args[0], &option);
-			if (r < 0) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "integer field, but no integer?\n");
-				ret = r;
-				continue;
-			}
-			v9ses->dfltgid = make_kgid(current_user_ns(), option);
-			if (!gid_valid(v9ses->dfltgid)) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "gid field, but not a gid?\n");
-				ret = -EINVAL;
-			}
-			break;
-		case Opt_afid:
-			r = match_int(&args[0], &option);
-			if (r < 0) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "integer field, but no integer?\n");
-				ret = r;
-			} else {
-				v9ses->afid = option;
-			}
-			break;
-		case Opt_uname:
-			kfree(v9ses->uname);
-			v9ses->uname = match_strdup(&args[0]);
-			if (!v9ses->uname) {
-				ret = -ENOMEM;
-				goto free_and_return;
-			}
-			break;
-		case Opt_remotename:
-			kfree(v9ses->aname);
-			v9ses->aname = match_strdup(&args[0]);
-			if (!v9ses->aname) {
-				ret = -ENOMEM;
-				goto free_and_return;
-			}
-			break;
-		case Opt_nodevmap:
-			v9ses->nodev = 1;
-			break;
-		case Opt_noxattr:
-			v9ses->flags |= V9FS_NO_XATTR;
-			break;
-		case Opt_directio:
-			v9ses->flags |= V9FS_DIRECT_IO;
-			break;
-		case Opt_ignoreqv:
-			v9ses->flags |= V9FS_IGNORE_QV;
-			break;
-		case Opt_cachetag:
-#ifdef CONFIG_9P_FSCACHE
-			kfree(v9ses->cachetag);
-			v9ses->cachetag = match_strdup(&args[0]);
-			if (!v9ses->cachetag) {
-				ret = -ENOMEM;
-				goto free_and_return;
-			}
-#endif
-			break;
-		case Opt_cache:
-			s = match_strdup(&args[0]);
-			if (!s) {
-				ret = -ENOMEM;
-				p9_debug(P9_DEBUG_ERROR,
-					 "problem allocating copy of cache arg\n");
-				goto free_and_return;
-			}
-			r = get_cache_mode(s);
-			if (r < 0)
-				ret = r;
-			else
-				v9ses->cache = r;
-
-			kfree(s);
-			break;
-
-		case Opt_access:
-			s = match_strdup(&args[0]);
-			if (!s) {
-				ret = -ENOMEM;
-				p9_debug(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;
-			else if (strcmp(s, "any") == 0)
-				v9ses->flags |= V9FS_ACCESS_ANY;
-			else if (strcmp(s, "client") == 0) {
-				v9ses->flags |= V9FS_ACCESS_CLIENT;
-			} else {
-				uid_t uid;
-
-				v9ses->flags |= V9FS_ACCESS_SINGLE;
-				r = kstrtouint(s, 10, &uid);
-				if (r) {
-					ret = r;
-					pr_info("Unknown access argument %s: %d\n",
-						s, r);
-					kfree(s);
-					continue;
-				}
-				v9ses->uid = make_kuid(current_user_ns(), uid);
-				if (!uid_valid(v9ses->uid)) {
-					ret = -EINVAL;
-					pr_info("Unknown uid %s\n", s);
-				}
-			}
-
-			kfree(s);
-			break;
-
-		case Opt_posixacl:
-#ifdef CONFIG_9P_FS_POSIX_ACL
-			v9ses->flags |= V9FS_POSIX_ACL;
-#else
-			p9_debug(P9_DEBUG_ERROR,
-				 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
-#endif
-			break;
-
-		case Opt_locktimeout:
-			r = match_int(&args[0], &option);
-			if (r < 0) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "integer field, but no integer?\n");
-				ret = r;
-				continue;
-			}
-			if (option < 1) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "locktimeout must be a greater than zero integer.\n");
-				ret = -EINVAL;
-				continue;
-			}
-			v9ses->session_lock_timeout = (long)option * HZ;
-			break;
-
-		default:
-			continue;
+	switch (opt) {
+	case Opt_source:
+		if (fc->source) {
+			pr_info("p9: multiple sources not supported\n");
+			return -EINVAL;
 		}
+		fc->source = param->string;
+		param->string = NULL;
+		break;
+	case Opt_debug:
+		session_opts->debug = result.uint_32;
+#ifdef CONFIG_NET_9P_DEBUG
+		p9_debug_level = result.uint_32;
+#endif
+		break;
+
+	case Opt_dfltuid:
+		session_opts->dfltuid = result.uid;
+		break;
+	case Opt_dfltgid:
+		session_opts->dfltgid = result.gid;
+		break;
+	case Opt_afid:
+		session_opts->afid = result.uint_32;
+		break;
+	case Opt_uname:
+		kfree(session_opts->uname);
+		session_opts->uname = param->string;
+		param->string = NULL;
+		break;
+	case Opt_remotename:
+		kfree(session_opts->aname);
+		session_opts->aname = param->string;
+		param->string = NULL;
+		break;
+	case Opt_nodevmap:
+		session_opts->nodev = 1;
+		break;
+	case Opt_noxattr:
+		session_opts->flags |= V9FS_NO_XATTR;
+		break;
+	case Opt_directio:
+		session_opts->flags |= V9FS_DIRECT_IO;
+		break;
+	case Opt_ignoreqv:
+		session_opts->flags |= V9FS_IGNORE_QV;
+		break;
+	case Opt_cachetag:
+#ifdef CONFIG_9P_FSCACHE
+		kfree(session_opts->cachetag);
+		session_opts->cachetag = param->string;
+		param->string = NULL;
+#endif
+		break;
+	case Opt_cache:
+		r = get_cache_mode(param->string);
+		if (r < 0)
+			return r;
+		session_opts->cache = r;
+		break;
+	case Opt_access:
+		s = param->string;
+		session_opts->flags &= ~V9FS_ACCESS_MASK;
+		if (strcmp(s, "user") == 0) {
+			session_opts->flags |= V9FS_ACCESS_USER;
+		} else if (strcmp(s, "any") == 0) {
+			session_opts->flags |= V9FS_ACCESS_ANY;
+		} else if (strcmp(s, "client") == 0) {
+			session_opts->flags |= V9FS_ACCESS_CLIENT;
+		} else {
+			uid_t uid;
+
+			session_opts->flags |= V9FS_ACCESS_SINGLE;
+			r = kstrtouint(s, 10, &uid);
+			if (r) {
+				pr_info("Unknown access argument %s: %d\n",
+					param->string, r);
+				return r;
+			}
+			session_opts->uid = make_kuid(current_user_ns(), uid);
+			if (!uid_valid(session_opts->uid)) {
+				pr_info("Unknown uid %s\n", s);
+				return -EINVAL;
+			}
+		}
+		break;
+
+	case Opt_posixacl:
+#ifdef CONFIG_9P_FS_POSIX_ACL
+		session_opts->flags |= V9FS_POSIX_ACL;
+#else
+		p9_debug(P9_DEBUG_ERROR,
+			 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
+#endif
+		break;
+
+	case Opt_locktimeout:
+		if (result.uint_32 < 1) {
+			p9_debug(P9_DEBUG_ERROR,
+				 "locktimeout must be a greater than zero integer.\n");
+			return -EINVAL;
+		}
+		session_opts->session_lock_timeout = (long)result.uint_32 * HZ;
+		break;
+
+	/* Options for client */
+	case Opt_msize:
+		if (result.uint_32 < 4096) {
+			p9_debug(P9_DEBUG_ERROR, "msize should be at least 4k\n");
+			return -EINVAL;
+		}
+		if (result.uint_32 > INT_MAX) {
+			p9_debug(P9_DEBUG_ERROR, "msize too big\n");
+			return -EINVAL;
+		}
+		clnt->msize = result.uint_32;
+		break;
+	case Opt_trans:
+		v9fs_put_trans(clnt->trans_mod);
+		clnt->trans_mod = v9fs_get_trans_by_name(param->string);
+		if (!clnt->trans_mod) {
+			pr_info("Could not find request transport: %s\n",
+				param->string);
+			return -EINVAL;
+		}
+		break;
+	case Opt_legacy:
+		clnt->proto_version = p9_proto_legacy;
+		break;
+	case Opt_version:
+		clnt->proto_version = result.uint_32;
+		p9_debug(P9_DEBUG_9P, "Protocol version: %s\n", param->string);
+		break;
+	/* Options for fd transport */
+	case Opt_rfdno:
+		fd_opts->rfd = result.uint_32;
+		break;
+	case Opt_wfdno:
+		fd_opts->wfd = result.uint_32;
+		break;
+	/* Options for rdma transport */
+	case Opt_sq_depth:
+		rdma_opts->sq_depth = result.uint_32;
+		break;
+	case Opt_rq_depth:
+		rdma_opts->rq_depth = result.uint_32;
+		break;
+	case Opt_timeout:
+		rdma_opts->timeout = result.uint_32;
+		break;
+	/* Options for both fd and rdma transports */
+	case Opt_port:
+		fd_opts->port = result.uint_32;
+		rdma_opts->port = result.uint_32;
+		break;
+	case Opt_privport:
+		fd_opts->privport = true;
+		rdma_opts->port = true;
+		break;
 	}
 
-free_and_return:
-	kfree(tmp_options);
-fail_option_alloc:
-	return ret;
+	return 0;
+}
+
+static void v9fs_apply_options(struct v9fs_session_info *v9ses,
+		  struct fs_context *fc)
+{
+	struct v9fs_context	*ctx = fc->fs_private;
+
+	v9ses->debug = ctx->session_opts.debug;
+	v9ses->dfltuid = ctx->session_opts.dfltuid;
+	v9ses->dfltgid = ctx->session_opts.dfltgid;
+	v9ses->afid = ctx->session_opts.afid;
+	v9ses->uname = ctx->session_opts.uname;
+	ctx->session_opts.uname = NULL;
+	v9ses->aname = ctx->session_opts.aname;
+	ctx->session_opts.aname = NULL;
+	v9ses->nodev = ctx->session_opts.nodev;
+	/*
+	 * Note that we must |= flags here as session_init already
+	 * set basic flags. This adds in flags from parsed options.
+	 */
+	v9ses->flags |= ctx->session_opts.flags;
+#ifdef CONFIG_9P_FSCACHE
+	v9ses->cachetag = ctx->session_opts.cachetag;
+	ctx->session_opts.cachetag = NULL;
+#endif
+	v9ses->cache = ctx->session_opts.cache;
+	v9ses->uid = ctx->session_opts.uid;
+	v9ses->session_lock_timeout = ctx->session_opts.session_lock_timeout;
 }
 
 /**
  * v9fs_session_init - initialize session
  * @v9ses: session information structure
- * @dev_name: device being mounted
- * @data: options
+ * @fc: the filesystem mount context
  *
  */
 
 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
-		  const char *dev_name, char *data)
+		  struct fs_context *fc)
 {
 	struct p9_fid *fid;
 	int rc = -ENOMEM;
 
-	v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
-	if (!v9ses->uname)
-		goto err_names;
-
-	v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
-	if (!v9ses->aname)
-		goto err_names;
 	init_rwsem(&v9ses->rename_sem);
 
-	v9ses->uid = INVALID_UID;
-	v9ses->dfltuid = V9FS_DEFUID;
-	v9ses->dfltgid = V9FS_DEFGID;
-
-	v9ses->clnt = p9_client_create(dev_name, data);
+	v9ses->clnt = p9_client_create(fc);
 	if (IS_ERR(v9ses->clnt)) {
 		rc = PTR_ERR(v9ses->clnt);
 		p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
 		goto err_names;
 	}
 
+	/*
+	 * Initialize flags on the real v9ses. v9fs_apply_options below
+	 * will |= the additional flags from parsed options.
+	 */
 	v9ses->flags = V9FS_ACCESS_USER;
 
 	if (p9_is_proto_dotl(v9ses->clnt)) {
···
 		v9ses->flags |= V9FS_PROTO_2000U;
 	}
 
-	rc = v9fs_parse_options(v9ses, data);
-	if (rc < 0)
-		goto err_clnt;
+	v9fs_apply_options(v9ses, fc);
 
 	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 
···
 #ifdef CONFIG_9P_FSCACHE
 	/* register the session for caching */
 	if (v9ses->cache & CACHE_FSCACHE) {
-		rc = v9fs_cache_session_get_cookie(v9ses, dev_name);
+		rc = v9fs_cache_session_get_cookie(v9ses, fc->source);
 		if (rc < 0)
 			goto err_clnt;
 	}

fs/9p/v9fs.h

···
 
 #include <linux/backing-dev.h>
 #include <linux/netfs.h>
+#include <linux/fs_parser.h>
+#include <net/9p/client.h>
+#include <net/9p/transport.h>
 
 /**
  * enum p9_session_flags - option flags for each 9P session
···
 #endif
 }
 
+extern const struct fs_parameter_spec v9fs_param_spec[];
 
+extern int v9fs_parse_param(struct fs_context *fc, struct fs_parameter *param);
 extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
 
 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
-				 const char *dev_name, char *data);
+				 struct fs_context *fc);
 extern void v9fs_session_close(struct v9fs_session_info *v9ses);
 extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);

fs/9p/vfs_dentry.c

···
 			p9_debug(P9_DEBUG_VFS,
 				"refresh inode: dentry = %pd (%p), got error %pe\n",
 				dentry, dentry, ERR_PTR(retval));
-		if (retval < 0)
 			return retval;
 		}
 	}

fs/9p/vfs_file.c

···
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid;
 	int omode;
+	int o_append;
 
 	p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
 	v9ses = v9fs_inode2v9ses(inode);
-	if (v9fs_proto_dotl(v9ses))
+	if (v9fs_proto_dotl(v9ses)) {
 		omode = v9fs_open_to_dotl_flags(file->f_flags);
-	else
+		o_append = P9_DOTL_APPEND;
+	} else {
 		omode = v9fs_uflags2omode(file->f_flags,
 					v9fs_proto_dotu(v9ses));
+		o_append = P9_OAPPEND;
+	}
 	fid = file->private_data;
 	if (!fid) {
 		fid = v9fs_fid_clone(file_dentry(file));
···
 			return PTR_ERR(fid);
 
 		if ((v9ses->cache & CACHE_WRITEBACK) && (omode & P9_OWRITE)) {
-			int writeback_omode = (omode & ~P9_OWRITE) | P9_ORDWR;
+			int writeback_omode = (omode & ~(P9_OWRITE | o_append)) | P9_ORDWR;
 
 			p9_debug(P9_DEBUG_CACHE, "write-only file with writeback enabled, try opening O_RDWR\n");
+
 			err = p9_client_open(fid, writeback_omode);
 			if (err < 0) {
 				p9_debug(P9_DEBUG_CACHE, "could not open O_RDWR, disabling caches\n");

fs/9p/vfs_inode.c

···
 	p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses));
 
 	if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
-		p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR;
+		p9_omode = (p9_omode & ~(P9_OWRITE | P9_OAPPEND)) | P9_ORDWR;
 		p9_debug(P9_DEBUG_CACHE,
 			"write-only file with writeback enabled, creating w/ O_RDWR\n");
 	}
···
 	.getattr = v9fs_vfs_getattr,
 	.setattr = v9fs_vfs_setattr,
 };
-

fs/9p/vfs_inode_dotl.c

···
 	}
 
 	if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
-		p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR;
+		p9_omode = (p9_omode & ~(P9_OWRITE | P9_DOTL_APPEND)) | P9_ORDWR;
 		p9_debug(P9_DEBUG_CACHE,
 			"write-only file with writeback enabled, creating w/ O_RDWR\n");
 	}

fs/9p/vfs_super.c

···
 #include <linux/statfs.h>
 #include <linux/magic.h>
 #include <linux/fscache.h>
+#include <linux/fs_context.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
 
···
 
 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;
 
-/**
- * v9fs_set_super - set the superblock
- * @s: super block
- * @data: file system specific data
- *
- */
-
-static int v9fs_set_super(struct super_block *s, void *data)
-{
-	s->s_fs_info = data;
-	return set_anon_super(s, data);
-}
-
-/**
- * v9fs_fill_super - populate superblock with info
- * @sb: superblock
- * @v9ses: session information
- * @flags: flags propagated from v9fs_mount()
- *
- */
-
-static int
-v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
-		int flags)
+static int v9fs_fill_super(struct super_block *sb)
 {
 	int ret;
+	struct v9fs_session_info *v9ses = v9ses = sb->s_fs_info;
 
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
 	sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
···
 }
 
 /**
- * v9fs_mount - mount a superblock
- * @fs_type: file system type
- * @flags: mount flags
- * @dev_name: device name that was mounted
- * @data: mount options
+ * v9fs_get_tree - create the mountable root and superblock
+ * @fc: the filesystem context
  *
  */
 
-static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
-		       const char *dev_name, void *data)
+static int v9fs_get_tree(struct fs_context *fc)
 {
 	struct super_block *sb = NULL;
 	struct inode *inode = NULL;
···
 
 	v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
 	if (!v9ses)
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 
-	fid = v9fs_session_init(v9ses, dev_name, data);
+	fid = v9fs_session_init(v9ses, fc);
 	if (IS_ERR(fid)) {
 		retval = PTR_ERR(fid);
 		goto free_session;
 	}
 
-	sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses);
+	fc->s_fs_info = v9ses;
+	sb = sget_fc(fc, NULL, set_anon_super_fc);
 	if (IS_ERR(sb)) {
 		retval = PTR_ERR(sb);
 		goto clunk_fid;
 	}
-	retval = v9fs_fill_super(sb, v9ses, flags);
+	retval = v9fs_fill_super(sb);
 	if (retval)
 		goto release_sb;
 
···
 	v9fs_fid_add(root, &fid);
 
 	p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n");
-	return dget(sb->s_root);
+	fc->root = dget(sb->s_root);
+	return 0;
 
 clunk_fid:
 	p9_fid_put(fid);
 	v9fs_session_close(v9ses);
 free_session:
 	kfree(v9ses);
-	return ERR_PTR(retval);
+	return retval;
 
 release_sb:
 	/*
···
 	 */
 	p9_fid_put(fid);
 	deactivate_locked_super(sb);
-	return ERR_PTR(retval);
+	return retval;
 }
 
 /**
···
 	.write_inode = v9fs_write_inode_dotl,
 };
 
+static void v9fs_free_fc(struct fs_context *fc)
+{
+	struct v9fs_context *ctx = fc->fs_private;
+
+	if (!ctx)
+		return;
+
+	/* These should be NULL by now but guard against leaks */
+	kfree(ctx->session_opts.uname);
+	kfree(ctx->session_opts.aname);
+#ifdef CONFIG_9P_FSCACHE
+	kfree(ctx->session_opts.cachetag);
+#endif
+	if (ctx->client_opts.trans_mod)
+		v9fs_put_trans(ctx->client_opts.trans_mod);
+	kfree(ctx);
+}
+
+static const struct fs_context_operations v9fs_context_ops = {
+	.parse_param	= v9fs_parse_param,
+	.get_tree	= v9fs_get_tree,
+	.free		= v9fs_free_fc,
+};
+
+static int v9fs_init_fs_context(struct fs_context *fc)
+{
+	struct v9fs_context	*ctx;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	/* initialize core options */
+	ctx->session_opts.afid = ~0;
+	ctx->session_opts.cache = CACHE_NONE;
+	ctx->session_opts.session_lock_timeout = P9_LOCK_TIMEOUT;
+	ctx->session_opts.uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
+	if (!ctx->session_opts.uname)
+		goto error;
+
+	ctx->session_opts.aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
+	if (!ctx->session_opts.aname)
+		goto error;
+
+	ctx->session_opts.uid = INVALID_UID;
+	ctx->session_opts.dfltuid = V9FS_DEFUID;
+	ctx->session_opts.dfltgid = V9FS_DEFGID;
+
+	/* initialize client options */
+	ctx->client_opts.proto_version = p9_proto_2000L;
+	ctx->client_opts.msize = DEFAULT_MSIZE;
+
+	/* initialize fd transport options */
+	ctx->fd_opts.port = P9_FD_PORT;
+	ctx->fd_opts.rfd = ~0;
+	ctx->fd_opts.wfd = ~0;
+	ctx->fd_opts.privport = false;
+
+	/* initialize rdma transport options */
+	ctx->rdma_opts.port = P9_RDMA_PORT;
+	ctx->rdma_opts.sq_depth = P9_RDMA_SQ_DEPTH;
+	ctx->rdma_opts.rq_depth = P9_RDMA_RQ_DEPTH;
+	ctx->rdma_opts.timeout = P9_RDMA_TIMEOUT;
+	ctx->rdma_opts.privport = false;
+
+	fc->ops = &v9fs_context_ops;
+	fc->fs_private = ctx;
+
+	return 0;
+error:
+	fc->need_free = 1;
+	return -ENOMEM;
+}
+
 struct file_system_type v9fs_fs_type = {
 	.name = "9p",
-	.mount = v9fs_mount,
 	.kill_sb = v9fs_kill_super,
 	.owner = THIS_MODULE,
 	.fs_flags = FS_RENAME_DOES_D_MOVE,
+	.init_fs_context = v9fs_init_fs_context,
+	.parameters = v9fs_param_spec,
 };
 MODULE_ALIAS_FS("9p");

include/linux/fs_parser.h

···
 #define fsparam_u32(NAME, OPT)	__fsparam(fs_param_is_u32, NAME, OPT, 0, NULL)
 #define fsparam_u32oct(NAME, OPT) \
 			__fsparam(fs_param_is_u32, NAME, OPT, 0, (void *)8)
+#define fsparam_u32hex(NAME, OPT) \
+			__fsparam(fs_param_is_u32, NAME, OPT, 0, (void *)16)
 #define fsparam_s32(NAME, OPT)	__fsparam(fs_param_is_s32, NAME, OPT, 0, NULL)
 #define fsparam_u64(NAME, OPT)	__fsparam(fs_param_is_u64, NAME, OPT, 0, NULL)
 #define fsparam_enum(NAME, OPT, array)	__fsparam(fs_param_is_enum, NAME, OPT, 0, array)

include/net/9p/client.h

···
 /* Number of requests per row */
 #define P9_ROW_MAXTAG 255
 
+/* DEFAULT MSIZE = 32 pages worth of payload + P9_HDRSZ +
+ * room for write (16 extra) or read (11 extra) operands.
+ */
+
+#define DEFAULT_MSIZE ((128 * 1024) + P9_IOHDRSZ)
+
 /** enum p9_proto_versions - 9P protocol versions
  * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
  * @p9_proto_2000u: 9P2000.u extension
···
 };
 
 /**
+ * struct p9_fd_opts - holds client options during parsing
+ * @msize: maximum data size negotiated by protocol
+ * @prot-Oversion: 9P protocol version to use
+ * @trans_mod: module API instantiated with this client
+ *
+ * These parsed options get transferred into client in
+ * apply_client_options()
+ */
+struct p9_client_opts {
+	unsigned int msize;
+	unsigned char proto_version;
+	struct p9_trans_module *trans_mod;
+};
+
+/**
+ * struct p9_fd_opts - per-transport options for fd transport
+ * @rfd: file descriptor for reading (trans=fd)
+ * @wfd: file descriptor for writing (trans=fd)
+ * @port: port to connect to (trans=tcp)
+ * @privport: port is privileged
+ */
+struct p9_fd_opts {
+	int rfd;
+	int wfd;
+	u16 port;
+	bool privport;
+};
+
+/**
+ * struct p9_rdma_opts - Collection of mount options for rdma transport
+ * @port: port of connection
+ * @privport: Whether a privileged port may be used
+ * @sq_depth: The requested depth of the SQ. This really doesn't need
+ * to be any deeper than the number of threads used in the client
+ * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
+ * @timeout: Time to wait in msecs for CM events
+ */
+struct p9_rdma_opts {
+	short port;
+	bool privport;
+	int sq_depth;
+	int rq_depth;
+	long timeout;
+};
+
+/**
+ * struct p9_session_opts - holds parsed options for v9fs_session_info
+ * @flags: session options of type &p9_session_flags
+ * @nodev: set to 1 to disable device mapping
+ * @debug: debug level
+ * @afid: authentication handle
+ * @cache: cache mode of type &p9_cache_bits
+ * @cachetag: the tag of the cache associated with this session
+ * @uname: string user name to mount hierarchy as
+ * @aname: mount specifier for remote hierarchy
+ * @dfltuid: default numeric userid to mount hierarchy as
+ * @dfltgid: default numeric groupid to mount hierarchy as
+ * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
+ * @session_lock_timeout: retry interval for blocking locks
+ *
+ * This strucure holds options which are parsed and will be transferred
+ * to the v9fs_session_info structure when mounted, and therefore largely
+ * duplicates struct v9fs_session_info.
+ */
+struct p9_session_opts {
+	unsigned int flags;
+	unsigned char nodev;
+	unsigned short debug;
+	unsigned int afid;
+	unsigned int cache;
+#ifdef CONFIG_9P_FSCACHE
+	char *cachetag;
+#endif
+	char *uname;
+	char *aname;
+	kuid_t dfltuid;
+	kgid_t dfltgid;
+	kuid_t uid;
+	long session_lock_timeout;
+};
+
+/* Used by mount API to store parsed mount options */
+struct v9fs_context {
+	struct p9_client_opts	client_opts;
+	struct p9_fd_opts	fd_opts;
+	struct p9_rdma_opts	rdma_opts;
+	struct p9_session_opts	session_opts;
+};
+
+/**
  * struct p9_fid - file system entity handle
  * @clnt: back pointer to instantiating &p9_client
  * @fid: numeric identifier for this handle
···
 		     const char *name);
 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
 		       struct p9_fid *newdirfid, const char *new_name);
-struct p9_client *p9_client_create(const char *dev_name, char *options);
+struct p9_client *p9_client_create(struct fs_context *fc);
 void p9_client_destroy(struct p9_client *clnt);
 void p9_client_disconnect(struct p9_client *clnt);
 void p9_client_begin_disconnect(struct p9_client *clnt);

include/net/9p/transport.h

···
 #define P9_DEF_MIN_RESVPORT	(665U)
 #define P9_DEF_MAX_RESVPORT	(1023U)
 
+#define P9_FD_PORT 564
+
+#define P9_RDMA_PORT		5640
+#define P9_RDMA_SQ_DEPTH	32
+#define P9_RDMA_RQ_DEPTH	32
+#define P9_RDMA_TIMEOUT		30000		/* 30 seconds */
+
 /**
  * struct p9_trans_module - transport module interface
  * @list: used to maintain a list of currently available transports
···
  *                   we're less flexible when choosing the response message
  *                   size in this case
  * @def: set if this transport should be considered the default
+ * @supports_vmalloc: set if this transport can work with vmalloc'd buffers
+ *                    (non-physically contiguous memory). Transports requiring
+ *                    DMA should leave this as false.
  * @create: member function to create a new connection on this transport
  * @close: member function to discard a connection on this transport
  * @request: member function to issue a request to the transport
···
 	char *name;		/* name of transport */
 	int maxsize;		/* max message size of transport */
 	bool pooled_rbuffers;
-	int def;		/* this transport should be default */
+	bool def;		/* this transport should be default */
+	bool supports_vmalloc;	/* can work with vmalloc'd buffers */
 	struct module *owner;
 	int (*create)(struct p9_client *client,
-		      const char *devname, char *args);
+		      struct fs_context *fc);
 	void (*close)(struct p9_client *client);
 	int (*request)(struct p9_client *client, struct p9_req_t *req);
 	int (*cancel)(struct p9_client *client, struct p9_req_t *req);

net/9p/client.c

···
 #include <linux/uio.h>
 #include <linux/netfs.h>
 #include <net/9p/9p.h>
-#include <linux/parser.h>
 #include <linux/seq_file.h>
+#include <linux/fs_context.h>
 #include <net/9p/client.h>
 #include <net/9p/transport.h>
 #include "protocol.h"
···
 #define CREATE_TRACE_POINTS
 #include <trace/events/9p.h>
 
-/* DEFAULT MSIZE = 32 pages worth of payload + P9_HDRSZ +
- * room for write (16 extra) or read (11 extra) operands.
- */
-
-#define DEFAULT_MSIZE ((128 * 1024) + P9_IOHDRSZ)
-
 /* Client Option Parsing (code inspired by NFS code)
  *  - a little lazy - parse all client options
  */
-
-enum {
-	Opt_msize,
-	Opt_trans,
-	Opt_legacy,
-	Opt_version,
-	Opt_err,
-};
-
-static const match_table_t tokens = {
-	{Opt_msize, "msize=%u"},
-	{Opt_legacy, "noextend"},
-	{Opt_trans, "trans=%s"},
-	{Opt_version, "version=%s"},
-	{Opt_err, NULL},
-};
 
 inline int p9_is_proto_dotl(struct p9_client *clnt)
 {
···
 	return err;
 }
 
-/* Interpret mount option for protocol version */
-static int get_protocol_version(char *s)
+static int apply_client_options(struct p9_client *clnt, struct fs_context *fc)
 {
-	int version = -EINVAL;
+	struct v9fs_context *ctx = fc->fs_private;
 
-	if (!strcmp(s, "9p2000")) {
-		version = p9_proto_legacy;
-		p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
-	} else if (!strcmp(s, "9p2000.u")) {
-		version = p9_proto_2000u;
-		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
-	} else if (!strcmp(s, "9p2000.L")) {
-		version = p9_proto_2000L;
-		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
-	} else {
-		pr_info("Unknown protocol version %s\n", s);
-	}
+	clnt->msize = ctx->client_opts.msize;
+	clnt->trans_mod = ctx->client_opts.trans_mod;
+	ctx->client_opts.trans_mod = NULL;
+	clnt->proto_version = ctx->client_opts.proto_version;
 
-	return version;
-}
-
-/**
- * parse_opts - parse mount options into client structure
- * @opts: options string passed from mount
- * @clnt: existing v9fs client information
- *
- * Return 0 upon success, -ERRNO upon failure
- */
-
-static int parse_opts(char *opts, struct p9_client *clnt)
-{
-	char *options, *tmp_options;
-	char *p;
-	substring_t args[MAX_OPT_ARGS];
-	int option;
-	char *s;
-	int ret = 0;
-
-	clnt->proto_version = p9_proto_2000L;
-	clnt->msize = DEFAULT_MSIZE;
-
-	if (!opts)
-		return 0;
-
-	tmp_options = kstrdup(opts, GFP_KERNEL);
-	if (!tmp_options)
-		return -ENOMEM;
-	options = tmp_options;
-
-	while ((p = strsep(&options, ",")) != NULL) {
-		int token, r;
-
-		if (!*p)
-			continue;
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case Opt_msize:
-			r = match_int(&args[0], &option);
-			if (r < 0) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "integer field, but no integer?\n");
-				ret = r;
-				continue;
-			}
-			if (option < 4096) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "msize should be at least 4k\n");
-				ret = -EINVAL;
-				continue;
-			}
-			clnt->msize = option;
-			break;
-		case Opt_trans:
-			s = match_strdup(&args[0]);
-			if (!s) {
-				ret = -ENOMEM;
-				p9_debug(P9_DEBUG_ERROR,
-					 "problem allocating copy of trans arg\n");
-				goto free_and_return;
-			}
-
-			v9fs_put_trans(clnt->trans_mod);
-			clnt->trans_mod = v9fs_get_trans_by_name(s);
-			if (!clnt->trans_mod) {
-				pr_info("Could not find request transport: %s\n",
-					s);
-				ret = -EINVAL;
-			}
-			kfree(s);
-			break;
-		case Opt_legacy:
-			clnt->proto_version = p9_proto_legacy;
-			break;
-		case Opt_version:
-			s = match_strdup(&args[0]);
-			if (!s) {
-				ret = -ENOMEM;
-				p9_debug(P9_DEBUG_ERROR,
-					 "problem allocating copy of version arg\n");
-				goto free_and_return;
-			}
-			r = get_protocol_version(s);
-			if (r < 0)
-				ret = r;
-			else
-				clnt->proto_version = r;
-			kfree(s);
-			break;
-		default:
-			continue;
-		}
-	}
-
-free_and_return:
-	if (ret)
-		v9fs_put_trans(clnt->trans_mod);
-	kfree(tmp_options);
-	return ret;
+	return 0;
 }
 
 static int p9_fcall_init(struct p9_client *c, struct p9_fcall *fc,
···
 	if (likely(c->fcall_cache) && alloc_msize == c->msize) {
 		fc->sdata = kmem_cache_alloc(c->fcall_cache, GFP_NOFS);
 		fc->cache = c->fcall_cache;
+		if (!fc->sdata && c->trans_mod->supports_vmalloc) {
+			fc->sdata = kvmalloc(alloc_msize, GFP_NOFS);
+			fc->cache = NULL;
+		}
 	} else {
-		fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
+		if (c->trans_mod->supports_vmalloc)
+			fc->sdata = kvmalloc(alloc_msize, GFP_NOFS);
+		else
+			fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
 		fc->cache = NULL;
 	}
 	if (!fc->sdata)
···
 	if (fc->cache)
 		kmem_cache_free(fc->cache, fc->sdata);
 	else
-		kfree(fc->sdata);
+		kvfree(fc->sdata);
 }
 EXPORT_SYMBOL(p9_fcall_fini);
 
···
 	return err;
 }
 
-struct p9_client *p9_client_create(const char *dev_name, char *options)
+struct p9_client *p9_client_create(struct fs_context *fc)
 {
 	int err;
 	static atomic_t seqno = ATOMIC_INIT(0);
···
 	idr_init(&clnt->fids);
 	idr_init(&clnt->reqs);
 
-	err = parse_opts(options, clnt);
-	if (err < 0)
+	err = apply_client_options(clnt, fc);
+	if (err)
 		goto free_client;
 
 	if (!clnt->trans_mod)
···
 	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
 		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
 
-	err = clnt->trans_mod->create(clnt, dev_name, options);
+	err = clnt->trans_mod->create(clnt, fc);
 	if (err)
 		goto put_trans;
 

net/9p/mod.c

···
 #include <linux/moduleparam.h>
 #include <net/9p/9p.h>
 #include <linux/fs.h>
-#include <linux/parser.h>
 #include <net/9p/client.h>
 #include <net/9p/transport.h>
 #include <linux/list.h>
···
 	if (m)
 		module_put(m->owner);
 }
+EXPORT_SYMBOL(v9fs_put_trans);
 
 /**
  * init_p9 - Initialize module

net/9p/trans_fd.c

···
 #include <linux/uaccess.h>
 #include <linux/inet.h>
 #include <linux/file.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 #include <net/9p/9p.h>
···
 
 #include <linux/syscalls.h> /* killme */
 
-#define P9_PORT 564
 #define MAX_SOCK_BUF (1024*1024)
 #define MAXPOLLWADDR	2
 
 static struct p9_trans_module p9_tcp_trans;
 static struct p9_trans_module p9_fd_trans;
-
-/**
- * struct p9_fd_opts - per-transport options
- * @rfd: file descriptor for reading (trans=fd)
- * @wfd: file descriptor for writing (trans=fd)
- * @port: port to connect to (trans=tcp)
- * @privport: port is privileged
- */
-
-struct p9_fd_opts {
-	int rfd;
-	int wfd;
-	u16 port;
-	bool privport;
-};
-
-/*
-  * Option Parsing (code inspired by NFS code)
-  *  - a little lazy - parse all fd-transport options
-  */
-
-enum {
-	/* Options that take integer arguments */
-	Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
-	/* Options that take no arguments */
-	Opt_privport,
-};
-
-static const match_table_t tokens = {
-	{Opt_port, "port=%u"},
-	{Opt_rfdno, "rfdno=%u"},
-	{Opt_wfdno, "wfdno=%u"},
-	{Opt_privport, "privport"},
-	{Opt_err, NULL},
-};
 
 enum {
 	Rworksched = 1,		/* read work scheduled or running */
···
 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
 {
 	if (clnt->trans_mod == &p9_tcp_trans) {
-		if (clnt->trans_opts.tcp.port != P9_PORT)
+		if (clnt->trans_opts.tcp.port != P9_FD_PORT)
 			seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
 	} else if (clnt->trans_mod == &p9_fd_trans) {
 		if (clnt->trans_opts.fd.rfd != ~0)
···
 		if (clnt->trans_opts.fd.wfd != ~0)
 			seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
 	}
-	return 0;
-}
-
-/**
- * parse_opts - parse mount options into p9_fd_opts structure
- * @params: options string passed from mount
- * @opts: fd transport-specific structure to parse options into
- *
- * Returns 0 upon success, -ERRNO upon failure
- */
-
-static int parse_opts(char *params, struct p9_fd_opts *opts)
-{
-	char *p;
-	substring_t args[MAX_OPT_ARGS];
-	int option;
-	char *options, *tmp_options;
-
-	opts->port = P9_PORT;
-	opts->rfd = ~0;
-	opts->wfd = ~0;
-	opts->privport = false;
-
-	if (!params)
-		return 0;
-
-	tmp_options = kstrdup(params, GFP_KERNEL);
-	if (!tmp_options) {
-		p9_debug(P9_DEBUG_ERROR,
-			 "failed to allocate copy of option string\n");
-		return -ENOMEM;
-	}
-	options = tmp_options;
-
-	while ((p = strsep(&options, ",")) != NULL) {
-		int token;
-		int r;
-		if (!*p)
-			continue;
-		token = match_token(p, tokens, args);
-		if ((token != Opt_err) && (token != Opt_privport)) {
-			r = match_int(&args[0], &option);
-			if (r < 0) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "integer field, but no integer?\n");
-				continue;
-			}
-		}
-		switch (token) {
-		case Opt_port:
-			opts->port = option;
-			break;
-		case Opt_rfdno:
-			opts->rfd = option;
-			break;
-		case Opt_wfdno:
-			opts->wfd = option;
-			break;
-		case Opt_privport:
-			opts->privport = true;
-			break;
-		default:
-			continue;
-		}
-	}
-
-	kfree(tmp_options);
 	return 0;
 }
 
···
 }
 
 static int
-p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
+p9_fd_create_tcp(struct p9_client *client, struct fs_context *fc)
 {
+	const char *addr = fc->source;
+	struct v9fs_context *ctx = fc->fs_private;
 	int err;
 	char port_str[6];
 	struct socket *csocket;
 	struct sockaddr_storage stor = { 0 };
 	struct p9_fd_opts opts;
 
-	err = parse_opts(args, &opts);
-	if (err < 0)
-		return err;
+	/* opts are already parsed in context */
+	opts = ctx->fd_opts;
 
 	if (!addr)
 		return -EINVAL;
···
 }
 
 static int
-p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
+p9_fd_create_unix(struct p9_client *client, struct fs_context *fc)
 {
+	const char *addr = fc->source;
 	int err;
 	struct socket *csocket;
 	struct sockaddr_un sun_server;
···
 }
 
 static int
-p9_fd_create(struct p9_client *client, const char *addr, char *args)
+p9_fd_create(struct p9_client *client, struct fs_context *fc)
 {
+	struct v9fs_context *ctx = fc->fs_private;
+	struct p9_fd_opts opts = ctx->fd_opts;
 	int err;
-	struct p9_fd_opts opts;
 
-	err = parse_opts(args, &opts);
-	if (err < 0)
-		return err;
 	client->trans_opts.fd.rfd = opts.rfd;
 	client->trans_opts.fd.wfd = opts.wfd;
 
···
 	.name = "tcp",
 	.maxsize = MAX_SOCK_BUF,
 	.pooled_rbuffers = false,
-	.def = 0,
+	.def = false,
+	.supports_vmalloc = true,
 	.create = p9_fd_create_tcp,
 	.close = p9_fd_close,
 	.request = p9_fd_request,
···
 static struct p9_trans_module p9_unix_trans = {
 	.name = "unix",
 	.maxsize = MAX_SOCK_BUF,
-	.def = 0,
+	.def = false,
+	.supports_vmalloc = true,
 	.create = p9_fd_create_unix,
 	.close = p9_fd_close,
 	.request = p9_fd_request,
···
 static struct p9_trans_module p9_fd_trans = {
 	.name = "fd",
 	.maxsize = MAX_SOCK_BUF,
-	.def = 0,
+	.def = false,
+	.supports_vmalloc = true,
 	.create = p9_fd_create,
 	.close = p9_fd_close,
 	.request = p9_fd_request,

net/9p/trans_rdma.c

···
 #include <linux/uaccess.h>
 #include <linux/inet.h>
 #include <linux/file.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
 #include <linux/semaphore.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
···
 #include <rdma/ib_verbs.h>
 #include <rdma/rdma_cm.h>
 
-#define P9_PORT			5640
-#define P9_RDMA_SQ_DEPTH	32
-#define P9_RDMA_RQ_DEPTH	32
 #define P9_RDMA_SEND_SGE	4
 #define P9_RDMA_RECV_SGE	4
 #define P9_RDMA_IRD		0
 #define P9_RDMA_ORD		0
-#define P9_RDMA_TIMEOUT		30000		/* 30 seconds */
 #define P9_RDMA_MAXSIZE		(1024*1024)	/* 1MB */
 
 /**
···
 	};
 };
 
-/**
- * struct p9_rdma_opts - Collection of mount options
- * @port: port of connection
- * @privport: Whether a privileged port may be used
- * @sq_depth: The requested depth of the SQ. This really doesn't need
- * to be any deeper than the number of threads used in the client
- * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
- * @timeout: Time to wait in msecs for CM events
- */
-struct p9_rdma_opts {
-	short port;
-	bool privport;
-	int sq_depth;
-	int rq_depth;
-	long timeout;
-};
-
-/*
- * Option Parsing (code inspired by NFS code)
- */
-enum {
-	/* Options that take integer arguments */
-	Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout,
-	/* Options that take no argument */
-	Opt_privport,
-	Opt_err,
-};
-
-static match_table_t tokens = {
-	{Opt_port, "port=%u"},
-	{Opt_sq_depth, "sq=%u"},
-	{Opt_rq_depth, "rq=%u"},
-	{Opt_timeout, "timeout=%u"},
-	{Opt_privport, "privport"},
-	{Opt_err, NULL},
-};
-
 static int p9_rdma_show_options(struct seq_file *m, struct p9_client *clnt)
 {
 	struct p9_trans_rdma *rdma = clnt->trans;
 
-	if (rdma->port != P9_PORT)
+	if (rdma->port != P9_RDMA_PORT)
 		seq_printf(m, ",port=%u", rdma->port);
 	if (rdma->sq_depth != P9_RDMA_SQ_DEPTH)
 		seq_printf(m, ",sq=%u", rdma->sq_depth);
···
 		seq_printf(m, ",timeout=%lu", rdma->timeout);
 	if (rdma->privport)
 		seq_puts(m, ",privport");
-	return 0;
-}
-
-/**
- * parse_opts - parse mount options into rdma options structure
- * @params: options string passed from mount
- * @opts: rdma transport-specific structure to parse options into
- *
- * Returns 0 upon success, -ERRNO upon failure
- */
-static int parse_opts(char *params, struct p9_rdma_opts *opts)
-{
-	char *p;
-	substring_t args[MAX_OPT_ARGS];
-	int option;
-	char *options, *tmp_options;
-
-	opts->port = P9_PORT;
-	opts->sq_depth = P9_RDMA_SQ_DEPTH;
-	opts->rq_depth = P9_RDMA_RQ_DEPTH;
-	opts->timeout = P9_RDMA_TIMEOUT;
-	opts->privport = false;
-
-	if (!params)
-		return 0;
-
-	tmp_options = kstrdup(params, GFP_KERNEL);
-	if (!tmp_options) {
-		p9_debug(P9_DEBUG_ERROR,
-			 "failed to allocate copy of option string\n");
-		return -ENOMEM;
-	}
-	options = tmp_options;
-
-	while ((p = strsep(&options, ",")) != NULL) {
-		int token;
-		int r;
-		if (!*p)
-			continue;
-		token = match_token(p, tokens, args);
-		if ((token != Opt_err) && (token != Opt_privport)) {
-			r = match_int(&args[0], &option);
-			if (r < 0) {
-				p9_debug(P9_DEBUG_ERROR,
-					 "integer field, but no integer?\n");
-				continue;
-			}
-		}
-		switch (token) {
-		case Opt_port:
-			opts->port = option;
-			break;
-		case Opt_sq_depth:
-			opts->sq_depth = option;
-			break;
-		case Opt_rq_depth:
-			opts->rq_depth = option;
-			break;
-		case Opt_timeout:
-			opts->timeout = option;
-			break;
-		case Opt_privport:
-			opts->privport = true;
-			break;
-		default:
-			continue;
-		}
-	}
-	/* RQ must be at least as large as the SQ */
-	opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
-	kfree(tmp_options);
 	return 0;
 }
 
···
 /**
  * rdma_create_trans - Transport method for creating a transport instance
  * @client: client instance
- * @addr: IP address string
- * @args: Mount options string
+ * @fc: The filesystem context
  */
 static int
-rdma_create_trans(struct p9_client *client, const char *addr, char *args)
+rdma_create_trans(struct p9_client *client, struct fs_context *fc)
 {
+	const char *addr = fc->source;
+	struct v9fs_context *ctx = fc->fs_private;
+	struct p9_rdma_opts opts = ctx->rdma_opts;
 	int err;
-	struct p9_rdma_opts opts;
 	struct p9_trans_rdma *rdma;
 	struct rdma_conn_param conn_param;
 	struct ib_qp_init_attr qp_attr;
···
 	if (addr == NULL)
 		return -EINVAL;
 
-	/* Parse the transport specific mount options */
-	err = parse_opts(args, &opts);
-	if (err < 0)
-		return err;
+	/* options are already parsed, in the fs context */
+	opts = ctx->rdma_opts;
 
 	/* Create and initialize the RDMA transport structure */
 	rdma = alloc_rdma(&opts);
···
 	.name = "rdma",
 	.maxsize = P9_RDMA_MAXSIZE,
 	.pooled_rbuffers = true,
-	.def = 0,
+	.def = false,
+	.supports_vmalloc = false,
 	.owner = THIS_MODULE,
 	.create = rdma_create_trans,
 	.close = rdma_close,

net/9p/trans_usbg.c

···
 #include <linux/cleanup.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/fs_context.h>
 #include <linux/usb/composite.h>
 #include <linux/usb/func_utils.h>
 
···
 	return ret;
 }
 
-static int p9_usbg_create(struct p9_client *client, const char *devname, char *args)
+static int p9_usbg_create(struct p9_client *client, struct fs_context *fc)
 {
+	const char *devname = fc->source;
 	struct f_usb9pfs_dev *dev;
 	struct f_usb9pfs *usb9pfs;
 	int ret = -ENOENT;
···
 	.close = p9_usbg_close,
 	.request = p9_usbg_request,
 	.cancel = p9_usbg_cancel,
+	.supports_vmalloc = false,
 	.owner = THIS_MODULE,
 };
 

net/9p/trans_virtio.c

···
 #include <linux/highmem.h>
 #include <linux/slab.h>
 #include <net/9p/9p.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
 #include <net/9p/client.h>
 #include <net/9p/transport.h>
 #include <linux/scatterlist.h>
···
 /**
  * p9_virtio_create - allocate a new virtio channel
  * @client: client instance invoking this transport
- * @devname: string identifying the channel to connect to (unused)
- * @args: args passed from sys_mount() for per-transport options (unused)
+ * @fc: the filesystem context
  *
  * This sets up a transport channel for 9p communication.  Right now
  * we only match the first available channel, but eventually we could look up
···
  */
 
 static int
-p9_virtio_create(struct p9_client *client, const char *devname, char *args)
+p9_virtio_create(struct p9_client *client, struct fs_context *fc)
 {
+	const char *devname = fc->source;
 	struct virtio_chan *chan;
 	int ret = -ENOENT;
 	int found = 0;
···
 	 */
 	.maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3),
 	.pooled_rbuffers = false,
-	.def = 1,
+	.def = true,
+	.supports_vmalloc = false,
 	.owner = THIS_MODULE,
 };
 

net/9p/trans_xen.c

···
 
 #include <linux/module.h>
 #include <linux/spinlock.h>
+#include <linux/fs_context.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
 #include <net/9p/transport.h>
···
 	return 1;
 }
 
-static int p9_xen_create(struct p9_client *client, const char *addr, char *args)
+static int p9_xen_create(struct p9_client *client, struct fs_context *fc)
 {
+	const char *addr = fc->source;
 	struct xen_9pfs_front_priv *priv;
 
 	if (addr == NULL)
···
 	.name = "xen",
 	.maxsize = 1 << (XEN_9PFS_RING_ORDER + XEN_PAGE_SHIFT - 2),
 	.pooled_rbuffers = false,
-	.def = 1,
+	.def = true,
+	.supports_vmalloc = false,
 	.create = p9_xen_create,
 	.close = p9_xen_close,
 	.request = p9_xen_request,