Have fsdb(8) only mark a filesystem dirty when it is modified.

Until this update, the fsdb(8) command always marked a filesystem
as needing a full fsck unless it was run with the -n flag which
allowed no changes to be made.

This change tracks modifications to the filesystem. Two types of
changes are tracked. The first type of changes are those that are
not critical to the integrity of the filesystem such as changes to
owner, group, time stamps, access mode, and generation number. The
second type of changes are those that do affect the integrity of
the filesystem including zeroing inodes, changing block pointers,
directory entries, link counts, file lengths, file types, and file
flags.

When quitting having made no changes or only changes to data that
is not critical to filesystem integrity, the clean state of the
filesystem is left unchanged. But if filesystem critical data are
changed then fsdb will set the unclean flag which will require a
full fsck to be run before the filesystem can be mounted.

MFC-after:    1 week
Sponsored-by: The FreeBSD Foundation

2 files changed, 56 insertions, 56 deletions

diff --git a/sbin/fsdb/fsdb.c b/sbin/fsdb/fsdb.c
index 887a77dbb8cb..ceb4a884e885 100644
--- a/sbin/fsdb/fsdb.c
+++ b/sbin/fsdb/fsdb.c
@@ -63,6 +63,23 @@ static int find_blks64(uint64_t *buf, int size, uint64_t *blknum);
 static int find_indirblks32(uint32_t blk, int ind_level, uint32_t *blknum);
 static int find_indirblks64(uint64_t blk, int ind_level, uint64_t *blknum);
 
+/*
+ * Track modifications to the filesystem. Two types of changes are tracked.
+ * The first type of changes are those that are not critical to the integrity
+ * of the filesystem such as owner, group, time stamps, access mode, and
+ * generation number. The second type of changes are those that do affect
+ * the integrity of the filesystem including zeroing inodes, changing block
+ * pointers, directory entries, link counts, file lengths, file types and
+ * file flags.
+ *
+ * When quitting having made no changes or only changes to data that is not
+ * critical to filesystem integrity, the clean state of the filesystem is
+ * left unchanged. But if filesystem critical data are changed then fsdb
+ * will set the unclean flag which will require a full fsck to be run
+ * before the filesystem can be mounted.
+ */
+static int fsnoncritmodified;	/* filesystem non-critical modifications */
+static int fscritmodified;	/* filesystem integrity critical mods */
 struct inode curip;
 union dinode *curinode;
 ino_t curinum, ocurrent;
@@ -119,9 +136,13 @@ main(int argc, char *argv[])
 	       nflag? "Examining": "Editing", fsys, sblock.fs_fsmnt);
 	rval = cmdloop();
 	if (!nflag) {
-		sblock.fs_clean = 0;	/* mark it dirty */
-		sbdirty();
-		ckfini(0);
+		if (fscritmodified != 0) {
+			sblock.fs_clean = 0;	/* mark it dirty */
+			sbdirty();
+		}
+		ckfini(fscritmodified ? 0 : sblock.fs_clean);
+		if (fscritmodified == 0)
+			exit(0);
 		printf("*** FILE SYSTEM MARKED DIRTY\n");
 		printf("*** BE SURE TO RUN FSCK TO CLEAN UP ANY DAMAGE\n");
 		printf("*** IF IT IS MOUNTED, RE-MOUNT WITH -u -o reload\n");
@@ -167,36 +188,35 @@ struct cmdtable cmds[] = {
 	{ "help", "Print out help", 1, 1, FL_RO, helpfn },
 	{ "?", "Print out help", 1, 1, FL_RO, helpfn },
 	{ "inode", "Set active inode to INUM", 2, 2, FL_RO, focus },
-	{ "clri", "Clear inode INUM", 2, 2, FL_WR, zapi },
+	{ "clri", "Clear inode INUM", 2, 2, FL_CWR, zapi },
 	{ "lookup", "Set active inode by looking up NAME", 2, 2, FL_RO | FL_ST, focusname },
 	{ "cd", "Set active inode by looking up NAME", 2, 2, FL_RO | FL_ST, focusname },
 	{ "back", "Go to previous active inode", 1, 1, FL_RO, back },
 	{ "active", "Print active inode", 1, 1, FL_RO, active },
 	{ "print", "Print active inode", 1, 1, FL_RO, active },
 	{ "blocks", "Print block numbers of active inode", 1, 1, FL_RO, blocks },
-	{ "uplink", "Increment link count", 1, 1, FL_WR, uplink },
-	{ "downlink", "Decrement link count", 1, 1, FL_WR, downlink },
-	{ "linkcount", "Set link count to COUNT", 2, 2, FL_WR, linkcount },
+	{ "uplink", "Increment link count", 1, 1, FL_CWR, uplink },
+	{ "downlink", "Decrement link count", 1, 1, FL_CWR, downlink },
+	{ "linkcount", "Set link count to COUNT", 2, 2, FL_CWR, linkcount },
 	{ "findblk", "Find inode owning disk block(s)", 2, 33, FL_RO, findblk},
 	{ "ls", "List current inode as directory", 1, 1, FL_RO, ls },
-	{ "rm", "Remove NAME from current inode directory", 2, 2, FL_WR | FL_ST, rm },
-	{ "del", "Remove NAME from current inode directory", 2, 2, FL_WR | FL_ST, rm },
-	{ "ln", "Hardlink INO into current inode directory as NAME", 3, 3, FL_WR | FL_ST, ln },
-	{ "chinum", "Change dir entry number INDEX to INUM", 3, 3, FL_WR, chinum },
+	{ "rm", "Remove NAME from current inode directory", 2, 2, FL_CWR | FL_ST, rm },
+	{ "del", "Remove NAME from current inode directory", 2, 2, FL_CWR | FL_ST, rm },
+	{ "ln", "Hardlink INO into current inode directory as NAME", 3, 3, FL_CWR | FL_ST, ln },
+	{ "chinum", "Change dir entry number INDEX to INUM", 3, 3, FL_CWR, chinum },
 	{ "chname", "Change dir entry number INDEX to NAME", 3, 3, FL_WR | FL_ST, chname },
-	{ "chtype", "Change type of current inode to TYPE", 2, 2, FL_WR, newtype },
+	{ "chtype", "Change type of current inode to TYPE", 2, 2, FL_CWR, newtype },
 	{ "chmod", "Change mode of current inode to MODE", 2, 2, FL_WR, chmode },
-	{ "chlen", "Change length of current inode to LENGTH", 2, 2, FL_WR, chlen },
 	{ "chown", "Change owner of current inode to OWNER", 2, 2, FL_WR, chowner },
 	{ "chgrp", "Change group of current inode to GROUP", 2, 2, FL_WR, chgroup },
-	{ "chflags", "Change flags of current inode to FLAGS", 2, 2, FL_WR, chaflags },
+	{ "chflags", "Change flags of current inode to FLAGS", 2, 2, FL_CWR, chaflags },
 	{ "chgen", "Change generation number of current inode to GEN", 2, 2, FL_WR, chgen },
-	{ "chsize", "Change size of current inode to SIZE", 2, 2, FL_WR, chsize },
+	{ "chsize", "Change size of current inode to SIZE", 2, 2, FL_CWR, chsize },
 	{ "btime", "Change btime of current inode to BTIME", 2, 2, FL_WR, chbtime },
 	{ "mtime", "Change mtime of current inode to MTIME", 2, 2, FL_WR, chmtime },
 	{ "ctime", "Change ctime of current inode to CTIME", 2, 2, FL_WR, chctime },
 	{ "atime", "Change atime of current inode to ATIME", 2, 2, FL_WR, chatime },
-	{ "chdb", "Change db pointer N of current inode to BLKNO", 3, 3, FL_WR, chdb },
+	{ "chdb", "Change db pointer N of current inode to BLKNO", 3, 3, FL_CWR, chdb },
 	{ "quit", "Exit", 1, 1, FL_RO, quit },
 	{ "q", "Exit", 1, 1, FL_RO, quit },
 	{ "exit", "Exit", 1, 1, FL_RO, quit },
@@ -280,7 +300,7 @@ cmdloop(void)
 	    known = 0;
 	    for (cmdp = cmds; cmdp->cmd; cmdp++) {
 		if (!strcmp(cmdp->cmd, cmd_argv[0])) {
-		    if ((cmdp->flags & FL_WR) == FL_WR && nflag)
+		    if ((cmdp->flags & (FL_CWR | FL_WR)) != 0 && nflag)
 			warnx("`%s' requires write access", cmd_argv[0]),
 			    rval = 1;
 		    else if (cmd_argc >= cmdp->minargc &&
@@ -294,6 +314,12 @@ cmdloop(void)
 		    } else
 			rval = argcount(cmdp, cmd_argc, cmd_argv);
 		    known = 1;
+		    if (rval == 0) {
+			if ((cmdp->flags & FL_WR) != 0)
+			    fsnoncritmodified = 1;
+			if ((cmdp->flags & FL_CWR) != 0)
+			    fscritmodified = 1;
+		    }
 		    break;
 		}
 	    }
@@ -308,7 +334,7 @@ cmdloop(void)
 	    return 0;
 	}
 	if (rval)
-	    warnx("rval was %d", rval);
+	    warnx("command failed, return value was %d", rval);
     }
     el_end(elptr);
     history_end(hist);
@@ -930,30 +956,8 @@ CMDFUNCSTART(newtype)
     return 0;
 }
 
-CMDFUNCSTART(chlen)
-{
-    int rval = 1;
-    long len;
-    char *cp;
-
-    if (!checkactive())
-	return 1;
-
-    len = strtol(argv[1], &cp, 0);
-    if (cp == argv[1] || *cp != '\0' || len < 0) { 
-	warnx("bad length `%s'", argv[1]);
-	return 1;
-    }
-    
-    DIP_SET(curinode, di_size, len);
-    inodirty(&curip);
-    printactive(0);
-    return rval;
-}
-
 CMDFUNCSTART(chmode)
 {
-    int rval = 1;
     long modebits;
     char *cp;
 
@@ -970,12 +974,11 @@ CMDFUNCSTART(chmode)
     DIP_SET(curinode, di_mode, DIP(curinode, di_mode) | modebits);
     inodirty(&curip);
     printactive(0);
-    return rval;
+    return 0;
 }
 
 CMDFUNCSTART(chaflags)
 {
-    int rval = 1;
     u_long flags;
     char *cp;
 
@@ -995,12 +998,11 @@ CMDFUNCSTART(chaflags)
     DIP_SET(curinode, di_flags, flags);
     inodirty(&curip);
     printactive(0);
-    return rval;
+    return 0;
 }
 
 CMDFUNCSTART(chgen)
 {
-    int rval = 1;
     long gen;
     char *cp;
 
@@ -1013,19 +1015,19 @@ CMDFUNCSTART(chgen)
 	return 1;
     }
     
-    if (gen > INT_MAX || gen < INT_MIN) {
-	warnx("gen set beyond 32-bit range of field (%lx)\n", gen);
+    if (gen > UINT_MAX) {
+	warnx("gen set beyond 32-bit range of field (0x%lx), max is 0x%x\n",
+	    gen, UINT_MAX);
 	return(1);
     }
     DIP_SET(curinode, di_gen, gen);
     inodirty(&curip);
     printactive(0);
-    return rval;
+    return 0;
 }
 
 CMDFUNCSTART(chsize)
 {
-    int rval = 1;
     off_t size;
     char *cp;
 
@@ -1045,7 +1047,7 @@ CMDFUNCSTART(chsize)
     DIP_SET(curinode, di_size, size);
     inodirty(&curip);
     printactive(0);
-    return rval;
+    return 0;
 }
 
 CMDFUNC(chdb)
@@ -1080,7 +1082,6 @@ CMDFUNC(chdb)
 
 CMDFUNCSTART(linkcount)
 {
-    int rval = 1;
     int lcnt;
     char *cp;
 
@@ -1100,12 +1101,11 @@ CMDFUNCSTART(linkcount)
     DIP_SET(curinode, di_nlink, lcnt);
     inodirty(&curip);
     printactive(0);
-    return rval;
+    return 0;
 }
 
 CMDFUNCSTART(chowner)
 {
-    int rval = 1;
     unsigned long uid;
     char *cp;
     struct passwd *pwd;
@@ -1127,12 +1127,11 @@ CMDFUNCSTART(chowner)
     DIP_SET(curinode, di_uid, uid);
     inodirty(&curip);
     printactive(0);
-    return rval;
+    return 0;
 }
 
 CMDFUNCSTART(chgroup)
 {
-    int rval = 1;
     unsigned long gid;
     char *cp;
     struct group *grp;
@@ -1153,7 +1152,7 @@ CMDFUNCSTART(chgroup)
     DIP_SET(curinode, di_gid, gid);
     inodirty(&curip);
     printactive(0);
-    return rval;
+    return 0;
 }
 
 int
diff --git a/sbin/fsdb/fsdb.h b/sbin/fsdb/fsdb.h
index fee35886f675..d13caa3c0e93 100644
--- a/sbin/fsdb/fsdb.h
+++ b/sbin/fsdb/fsdb.h
@@ -49,7 +49,8 @@ struct cmdtable {
 	unsigned int flags;
 #define	FL_RO	0x0000		/* for symmetry */
 #define	FL_WR	0x0001		/* wants to write */
-#define	FL_ST	0x0002		/* resplit final string if argc > maxargc */
+#define	FL_CWR	0x0002		/* wants to write critical data */
+#define	FL_ST	0x0003		/* resplit final string if argc > maxargc */
 	int (*handler)(int argc, char *argv[]);
 };
 extern struct inode curip;