jffs2: add compr=lzo and compr=zlib options

..to allow forcing of either compression scheme.  This will override
compiled-in defaults.  jffs2_compress is reworked a bit, as the lzo/zlib
override shares lots of code w/ the PRIORITY mode.

v2: update show_options accordingly.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>

1 files changed, 24 insertions, 2 deletions

diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index 40f6e6385fd1..e7e974454115 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -82,6 +82,14 @@ static const char *jffs2_compr_name(unsigned int compr)
         switch (compr) {
         case JFFS2_COMPR_MODE_NONE:
                 return "none";
+#ifdef CONFIG_JFFS2_LZO
+        case JFFS2_COMPR_MODE_FORCELZO:
+                return "lzo";
+#endif
+#ifdef CONFIG_JFFS2_ZLIB
+        case JFFS2_COMPR_MODE_FORCEZLIB:
+                return "zlib";
+#endif
         default:
                 /* should never happen; programmer error */
                 WARN_ON(1);
@@ -195,11 +203,25 @@ static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
 
                         if (!name)
                                 return -ENOMEM;
-                        if (!strcmp(name, "none")) {
+                        if (!strcmp(name, "none"))
                                 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
-                                c->mount_opts.override_compr = true;
+#ifdef CONFIG_JFFS2_LZO
+                        else if (!strcmp(name, "lzo"))
+                                c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
+#endif
+#ifdef CONFIG_JFFS2_ZLIB
+                        else if (!strcmp(name, "zlib"))
+                                c->mount_opts.compr =
+                                                JFFS2_COMPR_MODE_FORCEZLIB;
+#endif
+                        else {
+                                printk(KERN_ERR "JFFS2 Error: unknown compressor \"%s\"",
+                                                name);
+                                kfree(name);
+                                return -EINVAL;
                         }
                         kfree(name);
+                        c->mount_opts.override_compr = true;
                         break;
                 default:
                         printk(KERN_ERR "JFFS2 Error: unrecognized mount option '%s' or missing value\n",