fs/9p: Consolidate file operations and add readahead and writeback

We had 3 different sets of file operations across 2 different protocol
variants differentiated by cache which really only changed 3
functions.  But the real problem is that certain file modes, mount
options, and other factors weren't being considered when we
decided whether or not to use caches.

This consolidates all the operations and switches
to conditionals within a common set to decide whether or not
to do different aspects of caching.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Reviewed-by: Dominique Martinet <asmadeus@codewreck.org>

1 files changed, 12 insertions, 18 deletions

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 61a51b90600d..a46bf9121f11 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -39,8 +39,6 @@ enum {
 	Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
 	/* Options that take no arguments */
 	Opt_nodevmap,
-	/* Cache options */
-	Opt_cache_loose, Opt_fscache, Opt_mmap,
 	/* Access options */
 	Opt_access, Opt_posixacl,
 	/* Lock timeout option */
@@ -58,9 +56,6 @@ static const match_table_t tokens = {
 	{Opt_remotename, "aname=%s"},
 	{Opt_nodevmap, "nodevmap"},
 	{Opt_cache, "cache=%s"},
-	{Opt_cache_loose, "loose"},
-	{Opt_fscache, "fscache"},
-	{Opt_mmap, "mmap"},
 	{Opt_cachetag, "cachetag=%s"},
 	{Opt_access, "access=%s"},
 	{Opt_posixacl, "posixacl"},
@@ -69,10 +64,12 @@ static const match_table_t tokens = {
 };
 
 static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
-	[CACHE_NONE]	= "none",
-	[CACHE_MMAP]	= "mmap",
-	[CACHE_LOOSE]	= "loose",
-	[CACHE_FSCACHE]	= "fscache",
+	[CACHE_NONE]		= "none",
+	[CACHE_READAHEAD]	= "readahead",
+	[CACHE_WRITEBACK]	= "writeback",
+	[CACHE_MMAP]		= "mmap",
+	[CACHE_LOOSE]		= "loose",
+	[CACHE_FSCACHE]		= "fscache",
 };
 
 /* Interpret mount options for cache mode */
@@ -89,6 +86,12 @@ static int get_cache_mode(char *s)
 	} else if (!strcmp(s, "mmap")) {
 		version = CACHE_MMAP;
 		p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
+	} else if (!strcmp(s, "writeback")) {
+		version = CACHE_WRITEBACK;
+		p9_debug(P9_DEBUG_9P, "Cache mode: writeback\n");
+	} else if (!strcmp(s, "readahead")) {
+		version = CACHE_READAHEAD;
+		p9_debug(P9_DEBUG_9P, "Cache mode: readahead\n");
 	} else if (!strcmp(s, "none")) {
 		version = CACHE_NONE;
 		p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
@@ -266,15 +269,6 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 		case Opt_nodevmap:
 			v9ses->nodev = 1;
 			break;
-		case Opt_cache_loose:
-			v9ses->cache = CACHE_LOOSE;
-			break;
-		case Opt_fscache:
-			v9ses->cache = CACHE_FSCACHE;
-			break;
-		case Opt_mmap:
-			v9ses->cache = CACHE_MMAP;
-			break;
 		case Opt_cachetag:
 #ifdef CONFIG_9P_FSCACHE
 			kfree(v9ses->cachetag);