xfs: online repair of realtime file bmaps

Repair the block mappings of realtime files.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

3 files changed, 174 insertions, 4 deletions

diff --git a/fs/xfs/scrub/bmap_repair.c b/fs/xfs/scrub/bmap_repair.c
index 188370660efc..d3ed1c884353 100644
--- a/fs/xfs/scrub/bmap_repair.c
+++ b/fs/xfs/scrub/bmap_repair.c
@@ -24,6 +24,7 @@
 #include "xfs_bmap_btree.h"
 #include "xfs_rmap.h"
 #include "xfs_rmap_btree.h"
+#include "xfs_rtrmap_btree.h"
 #include "xfs_refcount.h"
 #include "xfs_quota.h"
 #include "xfs_ialloc.h"
@@ -256,6 +257,96 @@ xrep_bmap_scan_ag(
 	return error;
 }
 
+/* Check for any obvious errors or conflicts in the file mapping. */
+STATIC int
+xrep_bmap_check_rtfork_rmap(
+	struct xfs_scrub		*sc,
+	const struct xfs_rmap_irec	*rec)
+{
+	/* xattr extents are never stored on realtime devices */
+	if (rec->rm_flags & XFS_RMAP_ATTR_FORK)
+		return -EFSCORRUPTED;
+
+	/* bmbt blocks are never stored on realtime devices */
+	if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
+		return -EFSCORRUPTED;
+
+	/* Data extents for non-rt files are never stored on the rt device. */
+	if (!XFS_IS_REALTIME_INODE(sc->ip))
+		return -EFSCORRUPTED;
+
+	/* Check the file offsets and physical extents. */
+	if (!xfs_verify_fileext(sc->mp, rec->rm_offset, rec->rm_blockcount))
+		return -EFSCORRUPTED;
+
+	/* Check that this fits in the rt volume. */
+	if (!xfs_verify_rtext(sc->mp, rec->rm_startblock, rec->rm_blockcount))
+		return -EFSCORRUPTED;
+
+	/* Make sure this isn't free space. */
+	return xrep_require_rtext_inuse(sc, rec->rm_startblock,
+			rec->rm_blockcount);
+}
+
+/* Record realtime extents that belong to this inode's fork. */
+STATIC int
+xrep_bmap_walk_rtrmap(
+	struct xfs_btree_cur		*cur,
+	const struct xfs_rmap_irec	*rec,
+	void				*priv)
+{
+	struct xrep_bmap		*rb = priv;
+	int				error = 0;
+
+	if (xchk_should_terminate(rb->sc, &error))
+		return error;
+
+	/* Skip extents which are not owned by this inode and fork. */
+	if (rec->rm_owner != rb->sc->ip->i_ino)
+		return 0;
+
+	error = xrep_bmap_check_rtfork_rmap(rb->sc, rec);
+	if (error)
+		return error;
+
+	/*
+	 * Record all blocks allocated to this file even if the extent isn't
+	 * for the fork we're rebuilding so that we can reset di_nblocks later.
+	 */
+	rb->nblocks += rec->rm_blockcount;
+
+	/* If this rmap isn't for the fork we want, we're done. */
+	if (rb->whichfork == XFS_DATA_FORK &&
+	    (rec->rm_flags & XFS_RMAP_ATTR_FORK))
+		return 0;
+	if (rb->whichfork == XFS_ATTR_FORK &&
+	    !(rec->rm_flags & XFS_RMAP_ATTR_FORK))
+		return 0;
+
+	return xrep_bmap_from_rmap(rb, rec->rm_offset, rec->rm_startblock,
+			rec->rm_blockcount,
+			rec->rm_flags & XFS_RMAP_UNWRITTEN);
+}
+
+/* Scan the realtime reverse mappings to build the new extent map. */
+STATIC int
+xrep_bmap_scan_rt(
+	struct xrep_bmap	*rb)
+{
+	struct xfs_scrub	*sc = rb->sc;
+	int			error;
+
+	if (xrep_is_rtmeta_ino(sc, sc->ip->i_ino))
+		return 0;
+
+	xchk_rt_lock(sc, &sc->sr);
+	xrep_rt_btcur_init(sc, &sc->sr);
+	error = xfs_rmap_query_all(sc->sr.rmap_cur, xrep_bmap_walk_rtrmap, rb);
+	xchk_rt_btcur_free(&sc->sr);
+	xchk_rt_unlock(sc, &sc->sr);
+	return error;
+}
+
 /*
  * Collect block mappings for this fork of this inode and decide if we have
  * enough space to rebuild.  Caller is responsible for cleaning up the list if
@@ -270,6 +361,12 @@ xrep_bmap_find_mappings(
 	xfs_agnumber_t		agno;
 	int			error = 0;
 
+	if (xfs_has_realtime(sc->mp)) {
+		error = xrep_bmap_scan_rt(rb);
+		if (error)
+			return error;
+	}
+
 	/* Iterate the rmaps for extents. */
 	for_each_perag(sc->mp, agno, pag) {
 		error = xrep_bmap_scan_ag(rb, pag);
@@ -605,10 +702,6 @@ xrep_bmap_check_inputs(
 		return -EINVAL;
 	}
 
-	/* Don't know how to rebuild realtime data forks. */
-	if (XFS_IS_REALTIME_INODE(sc->ip))
-		return -EOPNOTSUPP;
-
 	return 0;
 }
 
diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index e3e7f75778d6..1b9649407fa1 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -38,6 +38,8 @@
 #include "xfs_extfree_item.h"
 #include "xfs_reflink.h"
 #include "xfs_health.h"
+#include "xfs_rtrmap_btree.h"
+#include "xfs_rtalloc.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
@@ -2047,6 +2049,20 @@ xrep_ag_init(
 	return 0;
 }
 
+/* Initialize all the btree cursors for a RT repair. */
+void
+xrep_rt_btcur_init(
+	struct xfs_scrub	*sc,
+	struct xchk_rt		*sr)
+{
+	struct xfs_mount	*mp = sc->mp;
+
+	if (sc->sm->sm_type != XFS_SCRUB_TYPE_RTRMAPBT &&
+	    xfs_has_rtrmapbt(mp))
+		sr->rmap_cur = xfs_rtrmapbt_init_cursor(mp, sc->tp,
+				mp->m_rrmapip);
+}
+
 /* Reinitialize the per-AG block reservation for the AG we just fixed. */
 int
 xrep_reset_perag_resv(
@@ -2221,3 +2237,55 @@ xrep_dotdot_lookup(
 
 	return ino;
 }
+
+#ifdef CONFIG_XFS_RT
+/* Ensure that all rt blocks in the given range are not marked free. */
+int
+xrep_require_rtext_inuse(
+	struct xfs_scrub	*sc,
+	xfs_rtblock_t		rtbno,
+	xfs_filblks_t		len)
+{
+	struct xfs_mount	*mp = sc->mp;
+	xfs_rtblock_t		startext;
+	xfs_rtblock_t		endext;
+	uint32_t		mod;
+	bool			is_free = false;
+	int			error;
+
+	/* Round the starting rt extent down and the end rt extent up. */
+	startext = div_u64_rem(rtbno, mp->m_sb.sb_rextsize, &mod);
+	endext = div_u64_rem(rtbno + len - 1, mp->m_sb.sb_rextsize, &mod);
+
+	error = xfs_rtalloc_extent_is_free(mp, sc->tp, startext,
+			endext - startext + 1, &is_free);
+	if (error)
+		return error;
+	if (is_free)
+		return -EFSCORRUPTED;
+
+	return 0;
+}
+#endif
+
+/* Are we looking at a realtime metadata inode? */
+bool
+xrep_is_rtmeta_ino(
+	struct xfs_scrub	*sc,
+	xfs_ino_t		ino)
+{
+	/*
+	 * All filesystems have rt bitmap and summary inodes, even if they
+	 * don't have an rt section.
+	 */
+	if (ino == sc->mp->m_rbmip->i_ino)
+		return true;
+	if (ino == sc->mp->m_rsumip->i_ino)
+		return true;
+
+	/* Newer rt metadata files are not guaranteed to exist */
+	if (sc->mp->m_rrmapip && ino == sc->mp->m_rrmapip->i_ino)
+		return true;
+
+	return false;
+}
diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index c198f7cd3f99..e9ded3aa25d8 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -89,6 +89,15 @@ int xrep_setup_ag_allocbt(struct xfs_scrub *sc);
 void xrep_ag_btcur_init(struct xfs_scrub *sc, struct xchk_ag *sa);
 int xrep_ag_init(struct xfs_scrub *sc, struct xfs_perag *pag,
 		struct xchk_ag *sa);
+void xrep_rt_btcur_init(struct xfs_scrub *sc, struct xchk_rt *sr);
+
+#ifdef CONFIG_XFS_RT
+int xrep_require_rtext_inuse(struct xfs_scrub *sc, xfs_rtblock_t rtbno,
+		xfs_filblks_t len);
+#else
+# define xrep_require_rtext_inuse(sc, rtbno, len)	(-ENOSYS)
+#endif
+bool xrep_is_rtmeta_ino(struct xfs_scrub *sc, xfs_ino_t ino);
 
 /* Metadata revalidators */