fs/9p: Add new mount modes

Add some additional mount modes for cache management including
specifying directio as a mount option and an option for ignore
qid.version for determining whether or not a file is cacheable.
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>

fs/9p/v9fs.c

@@ -38,7 +38,7 @@ enum {
 	/* String options */
 	Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
 	/* Options that take no arguments */
-	Opt_nodevmap, Opt_noxattr,
+	Opt_nodevmap, Opt_noxattr, Opt_directio, Opt_ignoreqv,
 	/* Access options */
 	Opt_access, Opt_posixacl,
 	/* Lock timeout option */
@@ -56,6 +56,8 @@ static const match_table_t tokens = {
 	{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"},
@@ -125,7 +127,7 @@ int v9fs_show_options(struct seq_file *m, struct dentry *root)
 	if (v9ses->nodev)
 		seq_puts(m, ",nodevmap");
 	if (v9ses->cache)
-		seq_printf(m, ",%s", v9fs_cache_modes[v9ses->cache]);
+		seq_printf(m, ",cache=%s", v9fs_cache_modes[v9ses->cache]);
 #ifdef CONFIG_9P_FSCACHE
 	if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
 		seq_printf(m, ",cachetag=%s", v9ses->cachetag);
@@ -147,6 +149,10 @@ int v9fs_show_options(struct seq_file *m, struct dentry *root)
 		break;
 	}
 
+	if (v9ses->flags & V9FS_IGNORE_QV)
+		seq_puts(m, ",ignoreqv");
+	if (v9ses->flags & V9FS_DIRECT_IO)
+		seq_puts(m, ",directio");
 	if (v9ses->flags & V9FS_POSIX_ACL)
 		seq_puts(m, ",posixacl");
 
@@ -276,6 +282,12 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 		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);

fs/9p/v9fs.h

@@ -37,7 +37,10 @@ enum p9_session_flags {
 	V9FS_ACCESS_USER	= 0x08,
 	V9FS_ACCESS_CLIENT	= 0x10,
 	V9FS_POSIX_ACL		= 0x20,
-	V9FS_NO_XATTR		= 0x40
+	V9FS_NO_XATTR		= 0x40,
+	V9FS_IGNORE_QV		= 0x80, /* ignore qid.version for cache hints */
+	V9FS_DIRECT_IO		= 0x100,
+	V9FS_SYNC		= 0x200
 };
 
 /* possible values of ->cache */