From 69becf4a5ede05c5dc85723a979b46667aa4a26b Mon Sep 17 00:00:00 2001
From: Kirk McKusick <mckusick@FreeBSD.org>
Date: Tue, 3 Dec 2002 05:10:07 +0000
Subject: [PATCH] Properly handle UFS2 sparsely allocated inodes. The UFS2
 filesystem only preallocates a small number of inodes. The dump program tries
 to scan through all the allocated inodes on a filesystem which causes bad
 behavior if they have never been allocated. Thus dump must calculate the set
 of inodes that have actually been allocated and scan only those inodes.

Sponsored by:   DARPA & NAI Labs.
---
 sbin/dump/traverse.c | 91 ++++++++++++++++++++++++++++++++------------
 1 file changed, 66 insertions(+), 25 deletions(-)

diff --git a/sbin/dump/traverse.c b/sbin/dump/traverse.c
index b618cdfe91bd..988228389108 100644
--- a/sbin/dump/traverse.c
+++ b/sbin/dump/traverse.c
@@ -139,36 +139,77 @@ blockest(union dinode *dp)
 int
 mapfiles(ino_t maxino, long *tapesize)
 {
-	int mode;
-	ino_t ino;
-	union dinode *dp;
+	int i, cg, mode, inosused;
 	int anydirskipped = 0;
+	union dinode *dp;
+	struct cg *cgp;
+	ino_t ino;
+	char *cp;
 
-	for (ino = ROOTINO; ino < maxino; ino++) {
-		dp = getino(ino, &mode);
-		if (mode == 0)
-			continue;
+	if ((cgp = malloc(sblock->fs_cgsize)) == NULL)
+		quit("mapfiles: cannot allocate memory.\n");
+	for (cg = 0; cg < sblock->fs_ncg; cg++) {
+		ino = cg * sblock->fs_ipg;
+		bread(fsbtodb(sblock, cgtod(sblock, cg)), (char *)cgp,
+		    sblock->fs_cgsize);
+		if (sblock->fs_magic == FS_UFS2_MAGIC)
+			inosused = cgp->cg_initediblk;
+		else
+			inosused = sblock->fs_ipg;
 		/*
-		 * Everything must go in usedinomap so that a check
-		 * for "in dumpdirmap but not in usedinomap" to detect
-		 * dirs with nodump set has a chance of succeeding
-		 * (this is used in mapdirs()).
+		 * If we are using soft updates, then we can trust the
+		 * cylinder group inode allocation maps to tell us which
+		 * inodes are allocated. We will scan the used inode map
+		 * to find the inodes that are really in use, and then
+		 * read only those inodes in from disk.
 		 */
-		SETINO(ino, usedinomap);
-		if (mode == IFDIR)
-			SETINO(ino, dumpdirmap);
-		if (WANTTODUMP(dp)) {
-			SETINO(ino, dumpinomap);
-			if (mode != IFREG && mode != IFDIR && mode != IFLNK)
-				*tapesize += 1;
-			else
-				*tapesize += blockest(dp);
-			continue;
+		if (sblock->fs_flags & FS_DOSOFTDEP) {
+			if (!cg_chkmagic(cgp))
+				quit("mapfiles: cg %d: bad magic number\n", cg);
+			cp = &cg_inosused(cgp)[(inosused - 1) / CHAR_BIT];
+			for ( ; inosused > 0; inosused -= CHAR_BIT, cp--) {
+				if (*cp == 0)
+					continue;
+				for (i = 1 << (CHAR_BIT - 1); i > 0; i >>= 1) {
+					if (*cp & i)
+						break;
+					inosused--;
+				}
+				break;
+			}
+			if (inosused <= 0)
+				continue;
 		}
-		if (mode == IFDIR) {
-			if (!nonodump && (DIP(dp, di_flags) & UF_NODUMP))
-				CLRINO(ino, usedinomap);
-			anydirskipped = 1;
+		for (i = 0; i < inosused; i++, ino++) {
+			if (ino < ROOTINO ||
+			    (dp = getino(ino, &mode)) == NULL ||
+			    (mode & IFMT) == 0)
+				continue;
+			/*
+			 * Everything must go in usedinomap so that a check
+			 * for "in dumpdirmap but not in usedinomap" to detect
+			 * dirs with nodump set has a chance of succeeding
+			 * (this is used in mapdirs()).
+			 */
+			SETINO(ino, usedinomap);
+			if (mode == IFDIR)
+				SETINO(ino, dumpdirmap);
+			if (WANTTODUMP(dp)) {
+				SETINO(ino, dumpinomap);
+				if (mode != IFREG &&
+				    mode != IFDIR &&
+				    mode != IFLNK)
+					*tapesize += 1;
+				else
+					*tapesize += blockest(dp);
+				continue;
+			}
+			if (mode == IFDIR) {
+				if (!nonodump &&
+				    (DIP(dp, di_flags) & UF_NODUMP))
+					CLRINO(ino, usedinomap);
+				anydirskipped = 1;
+			}
 		}
 	}
 	/*