gfs2: Clean up gfs2_is_{ordered,writeback}

The gfs2_is_ordered and gfs2_is_writeback checks are weird in that they
implicitly check for !gfs2_is_jdata.  This makes understanding how to
use those functions correctly a challenge.  Clean this up by making
gfs2_is_ordered and gfs2_is_writeback take a super block instead of an
inode and by removing the implicit !gfs2_is_jdata checks.  Update the
callers accordingly.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/aops.c

@@ -930,14 +930,14 @@ static const struct address_space_operations gfs2_jdata_aops = {
 void gfs2_set_aops(struct inode *inode)
 {
 	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
 
-	if (gfs2_is_writeback(ip))
+	if (gfs2_is_jdata(ip))
+		inode->i_mapping->a_ops = &gfs2_jdata_aops;
+	else if (gfs2_is_writeback(sdp))
 		inode->i_mapping->a_ops = &gfs2_writeback_aops;
-	else if (gfs2_is_ordered(ip))
+	else if (gfs2_is_ordered(sdp))
 		inode->i_mapping->a_ops = &gfs2_ordered_aops;
-	else if (gfs2_is_jdata(ip))
-		inode->i_mapping->a_ops = &gfs2_jdata_aops;
 	else
 		BUG();
 }
-

fs/gfs2/inode.h

@@ -30,16 +30,14 @@ static inline int gfs2_is_jdata(const struct gfs2_inode *ip)
 	return ip->i_diskflags & GFS2_DIF_JDATA;
 }
 
-static inline int gfs2_is_writeback(const struct gfs2_inode *ip)
+static inline bool gfs2_is_ordered(const struct gfs2_sbd *sdp)
 {
-	const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
-	return (sdp->sd_args.ar_data == GFS2_DATA_WRITEBACK) && !gfs2_is_jdata(ip);
+	return sdp->sd_args.ar_data == GFS2_DATA_ORDERED;
 }
 
-static inline int gfs2_is_ordered(const struct gfs2_inode *ip)
+static inline bool gfs2_is_writeback(const struct gfs2_sbd *sdp)
 {
-	const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
-	return (sdp->sd_args.ar_data == GFS2_DATA_ORDERED) && !gfs2_is_jdata(ip);
+	return sdp->sd_args.ar_data == GFS2_DATA_WRITEBACK;
 }
 
 static inline int gfs2_is_dir(const struct gfs2_inode *ip)

fs/gfs2/log.h

@@ -51,12 +51,11 @@ static inline void gfs2_log_pointers_init(struct gfs2_sbd *sdp,
 
 static inline void gfs2_ordered_add_inode(struct gfs2_inode *ip)
 {
-	struct gfs2_sbd *sdp;
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 
-	if (!gfs2_is_ordered(ip))
+	if (gfs2_is_jdata(ip) || !gfs2_is_ordered(sdp))
 		return;
 
-	sdp = GFS2_SB(&ip->i_inode);
 	if (!test_bit(GIF_ORDERED, &ip->i_flags)) {
 		spin_lock(&sdp->sd_ordered_lock);
 		if (!test_and_set_bit(GIF_ORDERED, &ip->i_flags))