9p: convert to the new mount API

Convert 9p to the new mount API. This patch consolidates all parsing
into fs/9p/v9fs.c, which stores all results into a filesystem context
which can be passed to the various transports as needed.

Some of the parsing helper functions such as get_cache_mode() have been
eliminated in favor of using the new mount API's enum param type,
for simplicity.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Message-ID: <20251010214222.1347785-5-sandeen@redhat.com>
[ Dominique: handled source explicitly as per follow-up discussion ]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

1 files changed, 12 insertions, 136 deletions

diff --git a/net/9p/client.c b/net/9p/client.c
index 802f548332a5..f60d1d041adb 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -20,8 +20,8 @@
 #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"
@@ -33,22 +33,6 @@
  *  - 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 clnt->proto_version == p9_proto_2000L;
@@ -97,124 +81,16 @@ static int safe_errno(int err)
 	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;
-
-	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);
-	}
+	struct v9fs_context *ctx = fc->fs_private;
 
-	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;
+	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;
 
-	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,
@@ -975,7 +851,7 @@ error:
 	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);
@@ -998,8 +874,8 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
 	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)
@@ -1015,7 +891,7 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
 	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;