[JFFS2] Support new device nodes

Device node major/minor numbers are just stored in the payload of a single
data node. Just extend that to 4 bytes and use new_encode_dev() for it.

We only use the 4-byte format if we _need_ to, if !old_valid_dev(foo).
This preserves backwards compatibility with older code as much as
possible. If we do make devices with major or minor numbers above 255, and
then mount the file system with the old code, it'll just read the first
two bytes and get the numbers wrong. If it comes to garbage-collect it,
it'll then write back those wrong numbers. But that's about the best we
can expect.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 2 insertions, 5 deletions

diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c
index 967fb2cf8e21..77d30707de56 100644
--- a/fs/jffs2/gc.c
+++ b/fs/jffs2/gc.c
@@ -679,7 +679,7 @@ static int jffs2_garbage_collect_metadata(struct jffs2_sb_info *c, struct jffs2_
 	struct jffs2_full_dnode *new_fn;
 	struct jffs2_raw_inode ri;
 	struct jffs2_node_frag *last_frag;
-	jint16_t dev;
+	union jffs2_device_node dev;
 	char *mdata = NULL, mdatalen = 0;
 	uint32_t alloclen, phys_ofs, ilen;
 	int ret;
@@ -687,11 +687,8 @@ static int jffs2_garbage_collect_metadata(struct jffs2_sb_info *c, struct jffs2_
 	if (S_ISBLK(JFFS2_F_I_MODE(f)) ||
 	    S_ISCHR(JFFS2_F_I_MODE(f)) ) {
 		/* For these, we don't actually need to read the old node */
-		/* FIXME: for minor or major > 255. */
-		dev = cpu_to_je16(((JFFS2_F_I_RDEV_MAJ(f) << 8) |
-			JFFS2_F_I_RDEV_MIN(f)));
+		mdatalen = jffs2_encode_dev(&dev, JFFS2_F_I_RDEV(f));
 		mdata = (char *)&dev;
-		mdatalen = sizeof(dev);
 		D1(printk(KERN_DEBUG "jffs2_garbage_collect_metadata(): Writing %d bytes of kdev_t\n", mdatalen));
 	} else if (S_ISLNK(JFFS2_F_I_MODE(f))) {
 		mdatalen = fn->size;