xfs: update realtime super every time we update the primary fs super

Every time we update parts of the primary filesystem superblock that are
echoed in the rt superblock, we must update the rt super.  Avoid
changing the log to support logging to the rt device by using ordered
buffers.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_rtgroup.c

@@ -564,3 +564,63 @@ const struct xfs_buf_ops xfs_rtsb_buf_ops = {
 	.verify_write	= xfs_rtsb_write_verify,
 	.verify_struct	= xfs_rtsb_verify_all,
 };
+
+/* Update a realtime superblock from the primary fs super */
+void
+xfs_update_rtsb(
+	struct xfs_buf		*rtsb_bp,
+	const struct xfs_buf	*sb_bp)
+{
+	const struct xfs_dsb	*dsb = sb_bp->b_addr;
+	struct xfs_rtsb		*rsb = rtsb_bp->b_addr;
+	const uuid_t		*meta_uuid;
+
+	rsb->rsb_magicnum = cpu_to_be32(XFS_RTSB_MAGIC);
+
+	rsb->rsb_pad = 0;
+	memcpy(&rsb->rsb_fname, &dsb->sb_fname, XFSLABEL_MAX);
+
+	memcpy(&rsb->rsb_uuid, &dsb->sb_uuid, sizeof(rsb->rsb_uuid));
+
+	/*
+	 * The metadata uuid is the fs uuid if the metauuid feature is not
+	 * enabled.
+	 */
+	if (dsb->sb_features_incompat &
+				cpu_to_be32(XFS_SB_FEAT_INCOMPAT_META_UUID))
+		meta_uuid = &dsb->sb_meta_uuid;
+	else
+		meta_uuid = &dsb->sb_uuid;
+	memcpy(&rsb->rsb_meta_uuid, meta_uuid, sizeof(rsb->rsb_meta_uuid));
+}
+
+/*
+ * Update the realtime superblock from a filesystem superblock and log it to
+ * the given transaction.
+ */
+struct xfs_buf *
+xfs_log_rtsb(
+	struct xfs_trans	*tp,
+	const struct xfs_buf	*sb_bp)
+{
+	struct xfs_buf		*rtsb_bp;
+
+	if (!xfs_has_rtsb(tp->t_mountp))
+		return NULL;
+
+	rtsb_bp = xfs_trans_getrtsb(tp);
+	if (!rtsb_bp) {
+		/*
+		 * It's possible for the rtgroups feature to be enabled but
+		 * there is no incore rt superblock buffer if the rt geometry
+		 * was specified at mkfs time but the rt section has not yet
+		 * been attached.  In this case, rblocks must be zero.
+		 */
+		ASSERT(tp->t_mountp->m_sb.sb_rblocks == 0);
+		return NULL;
+	}
+
+	xfs_update_rtsb(rtsb_bp, sb_bp);
+	xfs_trans_ordered_buf(tp, rtsb_bp);
+	return rtsb_bp;
+}

fs/xfs/libxfs/xfs_rtgroup.h

@@ -251,6 +251,11 @@ static inline const char *xfs_rtginode_path(xfs_rgnumber_t rgno,
 {
 	return kasprintf(GFP_KERNEL, "%u.%s", rgno, xfs_rtginode_name(type));
 }
+
+void xfs_update_rtsb(struct xfs_buf *rtsb_bp,
+		const struct xfs_buf *sb_bp);
+struct xfs_buf *xfs_log_rtsb(struct xfs_trans *tp,
+		const struct xfs_buf *sb_bp);
 #else
 static inline void xfs_free_rtgroups(struct xfs_mount *mp,
 		xfs_rgnumber_t first_rgno, xfs_rgnumber_t end_rgno)
@@ -269,6 +274,8 @@ static inline int xfs_initialize_rtgroups(struct xfs_mount *mp,
 # define xfs_rtgroup_lock(rtg, gf)		((void)0)
 # define xfs_rtgroup_unlock(rtg, gf)		((void)0)
 # define xfs_rtgroup_trans_join(tp, rtg, gf)	((void)0)
+# define xfs_update_rtsb(bp, sb_bp)	((void)0)
+# define xfs_log_rtsb(tp, sb_bp)	(NULL)
 #endif /* CONFIG_XFS_RT */
 
 #endif /* __LIBXFS_RTGROUP_H */

fs/xfs/libxfs/xfs_sb.c

@@ -27,6 +27,7 @@
 #include "xfs_ag.h"
 #include "xfs_rtbitmap.h"
 #include "xfs_exchrange.h"
+#include "xfs_rtgroup.h"
 
 /*
  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
@@ -1276,10 +1277,12 @@ xfs_update_secondary_sbs(
  */
 int
 xfs_sync_sb_buf(
-	struct xfs_mount	*mp)
+	struct xfs_mount	*mp,
+	bool			update_rtsb)
 {
 	struct xfs_trans	*tp;
 	struct xfs_buf		*bp;
+	struct xfs_buf		*rtsb_bp = NULL;
 	int			error;
 
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0, 0, &tp);
@@ -1289,6 +1292,11 @@ xfs_sync_sb_buf(
 	bp = xfs_trans_getsb(tp);
 	xfs_log_sb(tp);
 	xfs_trans_bhold(tp, bp);
+	if (update_rtsb) {
+		rtsb_bp = xfs_log_rtsb(tp, bp);
+		if (rtsb_bp)
+			xfs_trans_bhold(tp, rtsb_bp);
+	}
 	xfs_trans_set_sync(tp);
 	error = xfs_trans_commit(tp);
 	if (error)
@@ -1297,7 +1305,11 @@ xfs_sync_sb_buf(
 	 * write out the sb buffer to get the changes to disk
 	 */
 	error = xfs_bwrite(bp);
+	if (!error && rtsb_bp)
+		error = xfs_bwrite(rtsb_bp);
 out:
+	if (rtsb_bp)
+		xfs_buf_relse(rtsb_bp);
 	xfs_buf_relse(bp);
 	return error;
 }

fs/xfs/libxfs/xfs_sb.h

@@ -15,7 +15,7 @@ struct xfs_perag;
 
 extern void	xfs_log_sb(struct xfs_trans *tp);
 extern int	xfs_sync_sb(struct xfs_mount *mp, bool wait);
-extern int	xfs_sync_sb_buf(struct xfs_mount *mp);
+extern int	xfs_sync_sb_buf(struct xfs_mount *mp, bool update_rtsb);
 extern void	xfs_sb_mount_common(struct xfs_mount *mp, struct xfs_sb *sbp);
 void		xfs_mount_sb_set_rextsize(struct xfs_mount *mp,
 			struct xfs_sb *sbp);

fs/xfs/xfs_buf_item_recover.c

@@ -1061,6 +1061,18 @@ xlog_recover_buf_commit_pass2(
 				current_lsn);
 		if (error)
 			goto out_release;
+
+		/* Update the rt superblock if we have one. */
+		if (xfs_has_rtsb(mp) && mp->m_rtsb_bp) {
+			struct xfs_buf	*rtsb_bp = mp->m_rtsb_bp;
+
+			xfs_buf_lock(rtsb_bp);
+			xfs_buf_hold(rtsb_bp);
+			xfs_update_rtsb(rtsb_bp, bp);
+			rtsb_bp->b_flags |= _XBF_LOGRECOVERY;
+			xfs_buf_delwri_queue(rtsb_bp, buffer_list);
+			xfs_buf_relse(rtsb_bp);
+		}
 	} else {
 		xlog_recover_do_reg_buffer(mp, item, bp, buf_f, current_lsn);
 	}

fs/xfs/xfs_ioctl.c

@@ -1028,7 +1028,7 @@ xfs_ioc_setlabel(
 	 * buffered reads from userspace (i.e. from blkid) are invalidated,
 	 * and userspace will see the newly-written label.
 	 */
-	error = xfs_sync_sb_buf(mp);
+	error = xfs_sync_sb_buf(mp, true);
 	if (error)
 		goto out;
 	/*
@@ -1039,6 +1039,8 @@ xfs_ioc_setlabel(
 	mutex_unlock(&mp->m_growlock);
 
 	invalidate_bdev(mp->m_ddev_targp->bt_bdev);
+	if (xfs_has_rtsb(mp) && mp->m_rtdev_targp)
+		invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
 
 out:
 	mnt_drop_write_file(filp);

fs/xfs/xfs_trans.c

@@ -25,6 +25,7 @@
 #include "xfs_dquot.h"
 #include "xfs_icache.h"
 #include "xfs_rtbitmap.h"
+#include "xfs_rtgroup.h"
 
 struct kmem_cache	*xfs_trans_cache;
 

fs/xfs/xfs_trans.h

@@ -214,6 +214,7 @@ xfs_trans_read_buf(
 }
 
 struct xfs_buf	*xfs_trans_getsb(struct xfs_trans *);
+struct xfs_buf	*xfs_trans_getrtsb(struct xfs_trans *tp);
 
 void		xfs_trans_brelse(xfs_trans_t *, struct xfs_buf *);
 void		xfs_trans_bjoin(xfs_trans_t *, struct xfs_buf *);

fs/xfs/xfs_trans_buf.c

@@ -168,12 +168,11 @@ xfs_trans_get_buf_map(
 /*
  * Get and lock the superblock buffer for the given transaction.
  */
-struct xfs_buf *
-xfs_trans_getsb(
-	struct xfs_trans	*tp)
+static struct xfs_buf *
+__xfs_trans_getsb(
+	struct xfs_trans	*tp,
+	struct xfs_buf		*bp)
 {
-	struct xfs_buf		*bp = tp->t_mountp->m_sb_bp;
-
 	/*
 	 * Just increment the lock recursion count if the buffer is already
 	 * attached to this transaction.
@@ -197,6 +196,22 @@ xfs_trans_getsb(
 	return bp;
 }
 
+struct xfs_buf *
+xfs_trans_getsb(
+	struct xfs_trans	*tp)
+{
+	return __xfs_trans_getsb(tp, tp->t_mountp->m_sb_bp);
+}
+
+struct xfs_buf *
+xfs_trans_getrtsb(
+	struct xfs_trans	*tp)
+{
+	if (!tp->t_mountp->m_rtsb_bp)
+		return NULL;
+	return __xfs_trans_getsb(tp, tp->t_mountp->m_rtsb_bp);
+}
+
 /*
  * Get and lock the buffer for the caller if it is not already
  * locked within the given transaction.  If it has not yet been