Have fsck_ffs(8) properly correct superblock check-hash failures.

Part of the problem was that fsck_ffs would read the superblock
multiple times complaining and repairing the superblock check hash
each time and then at the end failing to write out the superblock
with the corrected check hash. This fix reads the superblock just
once and if the check hash is corrected ensures that the fixed
superblock gets written.

Tested by:    Peter Holm
PR:           245916
MFC after:    1 week
Sponsored by: Netflix

1 files changed, 43 insertions, 139 deletions

diff --git a/sbin/fsck_ffs/setup.c b/sbin/fsck_ffs/setup.c
index 0ae7f1bbb28f..506a027f40ac 100644
--- a/sbin/fsck_ffs/setup.c
+++ b/sbin/fsck_ffs/setup.c
@@ -76,114 +76,19 @@ static int chkrecovery(int devfd);
 int
 setup(char *dev)
 {
-	long cg, asked, i, j;
-	long bmapsize;
-	struct stat statb;
+	long cg, bmapsize;
 	struct fs proto;
-	size_t size;
 
-	havesb = 0;
-	fswritefd = -1;
-	cursnapshot = 0;
-	if (stat(dev, &statb) < 0) {
-		printf("Can't stat %s: %s\n", dev, strerror(errno));
-		if (bkgrdflag) {
-			unlink(snapname);
-			bkgrdflag = 0;
-		}
-		return (0);
-	}
-	if ((statb.st_mode & S_IFMT) != S_IFCHR &&
-	    (statb.st_mode & S_IFMT) != S_IFBLK) {
-		if (bkgrdflag != 0 && (statb.st_flags & SF_SNAPSHOT) == 0) {
-			unlink(snapname);
-			printf("background fsck lacks a snapshot\n");
-			exit(EEXIT);
-		}
-		if ((statb.st_flags & SF_SNAPSHOT) != 0 && cvtlevel == 0) {
-			cursnapshot = statb.st_ino;
-		} else {
-			if (cvtlevel == 0 ||
-			    (statb.st_flags & SF_SNAPSHOT) == 0) {
-				if (preen && bkgrdflag) {
-					unlink(snapname);
-					bkgrdflag = 0;
-				}
-				pfatal("%s is not a disk device", dev);
-				if (reply("CONTINUE") == 0) {
-					if (bkgrdflag) {
-						unlink(snapname);
-						bkgrdflag = 0;
-					}
-					return (0);
-				}
-			} else {
-				if (bkgrdflag) {
-					unlink(snapname);
-					bkgrdflag = 0;
-				}
-				pfatal("cannot convert a snapshot");
-				exit(EEXIT);
-			}
-		}
-	}
-	if ((fsreadfd = open(dev, O_RDONLY)) < 0) {
-		if (bkgrdflag) {
-			unlink(snapname);
-			bkgrdflag = 0;
-		}
-		printf("Can't open %s: %s\n", dev, strerror(errno));
+	/*
+	 * We are expected to have an open file descriptor
+	 */
+	if (fsreadfd < 0)
 		return (0);
-	}
-	if (bkgrdflag) {
-		unlink(snapname);
-		size = MIBSIZE;
-		if (sysctlnametomib("vfs.ffs.adjrefcnt", adjrefcnt, &size) < 0||
-		    sysctlnametomib("vfs.ffs.adjblkcnt", adjblkcnt, &size) < 0||
-		    sysctlnametomib("vfs.ffs.setsize", setsize, &size) < 0 ||
-		    sysctlnametomib("vfs.ffs.freefiles", freefiles, &size) < 0||
-		    sysctlnametomib("vfs.ffs.freedirs", freedirs, &size) < 0 ||
-		    sysctlnametomib("vfs.ffs.freeblks", freeblks, &size) < 0) {
-			pfatal("kernel lacks background fsck support\n");
-			exit(EEXIT);
-		}
-		/*
-		 * When kernel is lack of runtime bgfsck superblock summary
-		 * adjustment functionality, it does not mean we can not
-		 * continue, as old kernels will recompute the summary at
-		 * mount time.  However, it will be an unexpected softupdates
-		 * inconsistency if it turns out that the summary is still
-		 * incorrect.  Set a flag so subsequent operation can know
-		 * this.
-		 */
-		bkgrdsumadj = 1;
-		if (sysctlnametomib("vfs.ffs.adjndir", adjndir, &size) < 0 ||
-		    sysctlnametomib("vfs.ffs.adjnbfree", adjnbfree, &size) < 0 ||
-		    sysctlnametomib("vfs.ffs.adjnifree", adjnifree, &size) < 0 ||
-		    sysctlnametomib("vfs.ffs.adjnffree", adjnffree, &size) < 0 ||
-		    sysctlnametomib("vfs.ffs.adjnumclusters", adjnumclusters, &size) < 0) {
-			bkgrdsumadj = 0;
-			pwarn("kernel lacks runtime superblock summary adjustment support");
-		}
-		cmd.version = FFS_CMD_VERSION;
-		cmd.handle = fsreadfd;
-		fswritefd = -1;
-	}
-	if (preen == 0)
-		printf("** %s", dev);
-	if (bkgrdflag == 0 &&
-	    (nflag || (fswritefd = open(dev, O_WRONLY)) < 0)) {
-		fswritefd = -1;
-		if (preen)
-			pfatal("NO WRITE ACCESS");
-		printf(" (NO WRITE)");
-	}
-	if (preen == 0)
-		printf("\n");
 	/*
-	 * Read in the superblock, looking for alternates if necessary
+	 * If we do not yet have a superblock, read it in looking
+	 * for alternates if necessary.
 	 */
-	if (readsb(1) == 0) {
+	if (havesb == 0 && readsb(1) == 0) {
 		skipclean = 0;
 		if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0)
 			return(0);
@@ -195,19 +100,38 @@ setup(char *dev)
 				break;
 		}
 		if (cg >= proto.fs_ncg) {
-			printf("%s %s\n%s %s\n%s %s\n",
-				"SEARCH FOR ALTERNATE SUPER-BLOCK",
-				"FAILED. YOU MUST USE THE",
-				"-b OPTION TO FSCK TO SPECIFY THE",
-				"LOCATION OF AN ALTERNATE",
-				"SUPER-BLOCK TO SUPPLY NEEDED",
-				"INFORMATION; SEE fsck_ffs(8).");
+			printf("SEARCH FOR ALTERNATE SUPER-BLOCK FAILED. "
+			    "YOU MUST USE THE\n-b OPTION TO FSCK TO SPECIFY "
+			    "THE LOCATION OF AN ALTERNATE\nSUPER-BLOCK TO "
+			    "SUPPLY NEEDED INFORMATION; SEE fsck_ffs(8).\n");
 			bflag = 0;
 			return(0);
 		}
 		pwarn("USING ALTERNATE SUPERBLOCK AT %jd\n", bflag);
 		bflag = 0;
 	}
+	if (preen == 0)
+		printf("** %s", dev);
+	if (bkgrdflag == 0 &&
+	    (nflag || (fswritefd = open(dev, O_WRONLY)) < 0)) {
+		fswritefd = -1;
+		if (preen)
+			pfatal("NO WRITE ACCESS");
+		printf(" (NO WRITE)");
+	}
+	if (preen == 0)
+		printf("\n");
+	if (sbhashfailed != 0) {
+		pwarn("SUPERBLOCK CHECK HASH FAILED");
+		if (fswritefd == -1)
+			pwarn("OPENED READONLY SO CANNOT CORRECT CHECK HASH\n");
+		else if (preen || reply("CORRECT CHECK HASH") != 0) {
+			if (preen)
+				printf(" (CORRECTED)\n");
+			sblock.fs_clean = 0;
+			sbdirty();
+		}
+	}
 	if (skipclean && ckclean && sblock.fs_clean) {
 		pwarn("FILE SYSTEM CLEAN; SKIPPING CHECKS\n");
 		return (-1);
@@ -248,30 +172,6 @@ setup(char *dev)
 	    reply("SAVE DATA TO FIND ALTERNATE SUPERBLOCKS") != 0)
 		saverecovery(fsreadfd, fswritefd);
 	/*
-	 * read in the summary info.
-	 */
-	asked = 0;
-	sblock.fs_csp = Calloc(1, sblock.fs_cssize);
-	if (sblock.fs_csp == NULL) {
-		printf("cannot alloc %u bytes for cg summary info\n",
-		    (unsigned)sblock.fs_cssize);
-		goto badsb;
-	}
-	for (i = 0, j = 0; i < sblock.fs_cssize; i += sblock.fs_bsize, j++) {
-		size = MIN(sblock.fs_cssize - i, sblock.fs_bsize);
-		readcnt[sblk.b_type]++;
-		if (blread(fsreadfd, (char *)sblock.fs_csp + i,
-		    fsbtodb(&sblock, sblock.fs_csaddr + j * sblock.fs_frag),
-		    size) != 0 && !asked) {
-			pfatal("BAD SUMMARY INFORMATION");
-			if (reply("CONTINUE") == 0) {
-				ckfini(0);
-				exit(EEXIT);
-			}
-			asked++;
-		}
-	}
-	/*
 	 * allocate and initialize the necessary maps
 	 */
 	bmapsize = roundup(howmany(maxfsblock, CHAR_BIT), sizeof(short));
@@ -320,13 +220,17 @@ readsb(int listerr)
 	int bad, ret;
 	struct fs *fs;
 
-	super = bflag ? bflag * dev_bsize : STDSB_NOHASHFAIL;
+	super = bflag ? bflag * dev_bsize :
+	    sbhashfailed ? STDSB_NOHASHFAIL_NOMSG : STDSB_NOMSG;
 	readcnt[sblk.b_type]++;
-	if ((ret = sbget(fsreadfd, &fs, super)) != 0) {
+	while ((ret = sbget(fsreadfd, &fs, super)) != 0) {
 		switch (ret) {
-		case EINVAL:
-			/* Superblock check-hash failed */
-			return (0);
+		case EINTEGRITY:
+			if (bflag || super == STDSB_NOHASHFAIL_NOMSG)
+				return (0);
+			super = STDSB_NOHASHFAIL_NOMSG;
+			sbhashfailed = 1;
+			continue;
 		case ENOENT:
 			if (bflag)
 				printf("%jd is not a file system "