[3/4] xfs_repair: check the rt bitmap against observations

Commit Message

Darrick J. Wong May 5, 2022, 4:04 p.m. UTC

From: Darrick J. Wong <[e-mail]>

Teach xfs_repair to check the ondisk realtime bitmap against its own
observations.

Signed-off-by: Darrick J. Wong <[e-mail]>
---
 repair/phase5.c |    2 +
 repair/rt.c     |  168 ++++++++++++++++++++++++++-----------------------------
 repair/rt.h     |   11 ++--
 3 files changed, 87 insertions(+), 94 deletions(-)

Comments

Christoph Hellwig May 10, 2022, 12:53 p.m. UTC | #1

Looks good:

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/repair/phase5.c b/repair/phase5.c
index f097f0fe..ae444efb 100644
--- a/repair/phase5.c
+++ b/repair/phase5.c
@@ -616,6 +616,7 @@  phase5(xfs_mount_t *mp)
 		if (mp->m_sb.sb_rblocks) {
 			rtinit(mp);
 			generate_rtinfo(mp, btmcompute, sumcompute);
+			check_rtbitmap(mp);
 		}
 
 		return;
@@ -684,6 +685,7 @@  phase5(xfs_mount_t *mp)
 		_("        - generate realtime summary info and bitmap...\n"));
 		rtinit(mp);
 		generate_rtinfo(mp, btmcompute, sumcompute);
+		check_rtbitmap(mp);
 	}
 
 	do_log(_("        - reset superblock...\n"));
diff --git a/repair/rt.c b/repair/rt.c
index 3a065f4b..b964d168 100644
--- a/repair/rt.c
+++ b/repair/rt.c
@@ -119,6 +119,85 @@  generate_rtinfo(xfs_mount_t	*mp,
 	return(0);
 }
 
+static void
+check_rtfile_contents(
+	struct xfs_mount	*mp,
+	const char		*filename,
+	xfs_ino_t		ino,
+	void			*buf,
+	xfs_fileoff_t		filelen)
+{
+	struct xfs_bmbt_irec	map;
+	struct xfs_buf		*bp;
+	struct xfs_inode	*ip;
+	xfs_fileoff_t		bno = 0;
+	int			error;
+
+	error = -libxfs_iget(mp, NULL, ino, 0, &ip);
+	if (error) {
+		do_warn(_("unable to open %s file, err %d\n"), filename, error);
+		return;
+	}
+
+	if (ip->i_disk_size != XFS_FSB_TO_B(mp, filelen)) {
+		do_warn(_("expected %s file size %llu, found %llu\n"),
+				filename,
+				(unsigned long long)XFS_FSB_TO_B(mp, filelen),
+				(unsigned long long)ip->i_disk_size);
+	}
+
+	while (bno < filelen)  {
+		xfs_filblks_t	maplen;
+		int		nmap = 1;
+
+		/* Read up to 1MB at a time. */
+		maplen = min(filelen - bno, XFS_B_TO_FSBT(mp, 1048576));
+		error = -libxfs_bmapi_read(ip, bno, maplen, &map, &nmap, 0);
+		if (error) {
+			do_warn(_("unable to read %s mapping, err %d\n"),
+					filename, error);
+			break;
+		}
+
+		if (map.br_startblock == HOLESTARTBLOCK) {
+			do_warn(_("hole in %s file at dblock 0x%llx\n"),
+					filename, (unsigned long long)bno);
+			break;
+		}
+
+		error = -libxfs_buf_read_uncached(mp->m_dev,
+				XFS_FSB_TO_DADDR(mp, map.br_startblock),
+				XFS_FSB_TO_BB(mp, map.br_blockcount),
+				0, &bp, NULL);
+		if (error) {
+			do_warn(_("unable to read %s at dblock 0x%llx, err %d\n"),
+					filename, (unsigned long long)bno, error);
+			break;
+		}
+
+		if (memcmp(bp->b_addr, buf, mp->m_sb.sb_blocksize))
+			do_warn(_("discrepancy in %s at dblock 0x%llx\n"),
+					filename, (unsigned long long)bno);
+
+		buf += XFS_FSB_TO_B(mp, map.br_blockcount);
+		bno += map.br_blockcount;
+		libxfs_buf_relse(bp);
+	}
+
+	libxfs_irele(ip);
+}
+
+void
+check_rtbitmap(
+	struct xfs_mount	*mp)
+{
+	if (need_rbmino)
+		return;
+
+	check_rtfile_contents(mp, "rtbitmap", mp->m_sb.sb_rbmino, btmcompute,
+			mp->m_sb.sb_rbmblocks);
+}
+
 #if 0
 /*
  * returns 1 if bad, 0 if good
@@ -151,95 +230,6 @@  check_summary(xfs_mount_t *mp)
 	return(error);
 }
 
-/*
- * examine the real-time bitmap file and compute summary
- * info off it.  Should probably be changed to compute
- * the summary information off the incore computed bitmap
- * instead of the realtime bitmap file
- */
-void
-process_rtbitmap(
-	struct xfs_mount	*mp,
-	struct xfs_dinode	*dino,
-	blkmap_t		*blkmap)
-{
-	int			error;
-	int			bit;
-	int			bitsperblock;
-	int			bmbno;
-	int			end_bmbno;
-	xfs_fsblock_t		bno;
-	struct xfs_buf		*bp;
-	xfs_rtblock_t		extno;
-	int			i;
-	int			len;
-	int			log;
-	int			offs;
-	int			prevbit;
-	int			start_bmbno;
-	int			start_bit;
-	xfs_rtword_t		*words;
-
-	ASSERT(mp->m_rbmip == NULL);
-
-	bitsperblock = mp->m_sb.sb_blocksize * NBBY;
-	prevbit = 0;
-	extno = 0;
-	error = 0;
-
-	end_bmbno = howmany(be64_to_cpu(dino->di_size),
-						mp->m_sb.sb_blocksize);
-
-	for (bmbno = 0; bmbno < end_bmbno; bmbno++) {
-		bno = blkmap_get(blkmap, bmbno);
-
-		if (bno == NULLFSBLOCK) {
-			do_warn(_("can't find block %d for rtbitmap inode\n"),
-					bmbno);
-			error = 1;
-			continue;
-		}
-		error = -libxfs_buf_read(mp->m_dev, XFS_FSB_TO_DADDR(mp, bno),
-				XFS_FSB_TO_BB(mp, 1), 0, NULL, &bp);
-		if (error) {
-			do_warn(_("can't read block %d for rtbitmap inode\n"),
-					bmbno);
-			error = 1;
-			continue;
-		}
-		words = (xfs_rtword_t *)bp->b_un.b_addr;
-		for (bit = 0;
-		     bit < bitsperblock && extno < mp->m_sb.sb_rextents;
-		     bit++, extno++) {
-			if (xfs_isset(words, bit)) {
-				set_rtbmap(extno, XR_E_FREE);
-				sb_frextents++;
-				if (prevbit == 0) {
-					start_bmbno = bmbno;
-					start_bit = bit;
-					prevbit = 1;
-				}
-			} else if (prevbit == 1) {
-				len = (bmbno - start_bmbno) * bitsperblock +
-					(bit - start_bit);
-				log = XFS_RTBLOCKLOG(len);
-				offs = XFS_SUMOFFS(mp, log, start_bmbno);
-				sumcompute[offs]++;
-				prevbit = 0;
-			}
-		}
-		libxfs_buf_relse(bp);
-		if (extno == mp->m_sb.sb_rextents)
-			break;
-	}
-	if (prevbit == 1) {
-		len = (bmbno - start_bmbno) * bitsperblock + (bit - start_bit);
-		log = XFS_RTBLOCKLOG(len);
-		offs = XFS_SUMOFFS(mp, log, start_bmbno);
-		sumcompute[offs]++;
-	}
-}
-
 /*
  * copy the real-time summary file data into memory
  */
diff --git a/repair/rt.h b/repair/rt.h
index f5d8f80c..2023153f 100644
--- a/repair/rt.h
+++ b/repair/rt.h
@@ -3,6 +3,8 @@ 
  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
  * All Rights Reserved.
  */
+#ifndef _XFS_REPAIR_RT_H_
+#define _XFS_REPAIR_RT_H_
 
 struct blkmap;
 
@@ -14,17 +16,16 @@  generate_rtinfo(xfs_mount_t	*mp,
 		xfs_rtword_t	*words,
 		xfs_suminfo_t	*sumcompute);
 
+void check_rtbitmap(struct xfs_mount *mp);
+
 #if 0
 
 int
 check_summary(xfs_mount_t	*mp);
 
-void
-process_rtbitmap(xfs_mount_t		*mp,
-		struct xfs_dinode	*dino,
-		struct blkmap		*blkmap);
-
 void
 process_rtsummary(xfs_mount_t	*mp,
 		struct blkmap	*blkmap);
 #endif
+
+#endif /* _XFS_REPAIR_RT_H_ */