Add support for the -F flag which determines whether a specified

filesystem needs foreground checking (usually at boot time) or
can defer to background checking (after the system is up and running).
See the manual page, fsck_ffs(8), for details on the -F and -B options.
These options are primarily intended for use by the fsck front end.

All output is directed to stdout so that the output is coherent
when redirected to a file or a pipe. Unify the code with the fsck
front end that allows either a device or a mount point to be
specified as the argument to be checked.

sbin/fsck_ffs/fsck.h

@@ -212,6 +212,7 @@ int	cvtlevel;		/* convert to newer file system format */
 int	doinglevel1;		/* converting to new cylinder group format */
 int	doinglevel2;		/* converting to new inode format */
 int	newinofmt;		/* filesystem has new inode format */
+int	bkgrdcheck;		/* determine if background check is possible */
 char	usedsoftdep;		/* just fix soft dependency inconsistencies */
 char	preen;			/* just fix normal inconsistencies */
 char	rerun;			/* rerun fsck. Only used in non-preen mode */

sbin/fsck_ffs/fsck_ffs.8

@@ -42,41 +42,14 @@
 .Nd filesystem consistency check and interactive repair
 .Sh SYNOPSIS
 .Nm
-.Fl p
-.Op Fl f
-.Op Fl m Ar mode
-.Op Ar filesystem
-.Ar ...
-.Nm
-.Op Fl ny
+.Op Fl BFpfny
 .Op Fl b Ar block#
 .Op Fl c Ar level
-.Op Fl l Ar maxparallel
 .Op Fl m Ar mode
-.Op Ar filesystem
+.Ar filesystem
 .Ar ...
 .Sh DESCRIPTION
-The first form of
-.Nm
-preens a standard set of filesystems or the specified filesystems.
-It is normally used in the script
-.Pa /etc/rc
-during automatic reboot.
-Here
-.Nm
-reads the table
-.Pa /etc/fstab
-to determine which filesystems to check.
-Only partitions in fstab that are mounted ``rw,'' ``rq'' or ``ro''
-and that have non-zero pass number are checked.
-Filesystems with pass number 1 (normally just the root filesystem)
-are checked one at a time.
-When pass 1 completes, all remaining filesystems are checked,
-running one process per disk drive.
-The disk drive containing each filesystem is inferred from the longest prefix
-of the device name that ends in a digit; the remaining characters are assumed
-to be the partition designator.
-.Pp
+The specified disk partitions and/or filesystems are checked.
 In "preen" mode the clean flag of each filesystem's superblock is examined
 and only those filesystems that
 are not marked clean are checked.
@@ -166,17 +139,40 @@ will default to a
 .Fl n
 action.
 .Pp
-.Nm Fsck
-has more consistency checks than
-its predecessors
-.Em check , dcheck , fcheck ,
-and
-.Em icheck
-combined.
-.Pp
 The following flags are interpreted by
-.Nm .
+.Nm
 .Bl -tag -width indent
+.It Fl F
+Determine whether the filesystem needs to be cleaned immediately
+in foreground, or if its cleaning can be deferred to background.
+To be eligible for background cleaning it must have been running
+with soft updates, not have been marked as needing a foreground check,
+and be mounted and writable when the background check is to be done.
+If these conditions are met, then
+.Nm
+exits with a zero exit status.
+Otherwise it exits with a non-zero exit status.
+If the filesystem is clean,
+it will exit with a non-zero exit status so that the clean status
+of the filesystem can be verified and reported during the foreground
+checks.
+Note that when invoked with the
+.Fl F
+flag, no cleanups are done.
+The only thing that
+.Nm
+does is to determine whether a foreground or background
+check is needed and exit with an appropriate status code.
+.It Fl B
+A check is done on the specified and possibly active filesystem.
+The set of corrections that can be done is limited to those done
+when running in preen mode (see the
+.Fl p
+flag).
+If unexpected errors are found,
+the filesystem is marked as needing a foreground check and
+.Nm
+exits without attempting any further cleaning.
 .It Fl b
 Use the block specified immediately after the flag as
 the super block for the filesystem.  Block 32 is usually
@@ -220,12 +216,6 @@ Force
 to check
 .Sq clean
 filesystems when preening.
-.It Fl l
-Limit the number of parallel checks to the number specified in the following
-argument.
-By default, the limit is the number of disks, running one process per disk.
-If a smaller limit is given, the disks are checked round-robin, one filesystem
-at a time.
 .It Fl m
 Use the mode specified in octal immediately after the flag as the
 permission bits to use when creating the
@@ -250,12 +240,6 @@ this should be used with great caution as this is a free license
 to continue after essentially unlimited trouble has been encountered.
 .El
 .Pp
-If no filesystems are given to 
-.Nm
-then a default list of filesystems is read from
-the file
-.Pa /etc/fstab .
-.Pp
 Inconsistencies checked are as follows:
 .Pp
 .Bl -enum -compact
@@ -312,9 +296,6 @@ If the
 .Pa lost+found
 directory does not exist, it is created.
 If there is insufficient space its size is increased.
-.Pp
-Because of inconsistencies between the block device and the buffer cache,
-the raw device should always be used.
 .Sh FILES
 .Bl -tag -width /etc/fstab -compact
 .It Pa /etc/fstab

sbin/fsck_ffs/fsutil.c

@@ -264,6 +264,8 @@ rwerror(mesg, blk)
 	ufs_daddr_t blk;
 {
 
+	if (bkgrdcheck)
+		exit(EEXIT);
 	if (preen == 0)
 		printf("\n");
 	pfatal("CANNOT %s: %ld", mesg, blk);
@@ -645,10 +647,10 @@ pfatal(fmt, va_alist)
 	va_start(ap);
 #endif
 	if (!preen) {
-		(void)vfprintf(stderr, fmt, ap);
+		(void)vfprintf(stdout, fmt, ap);
 		va_end(ap);
 		if (usedsoftdep)
-			(void)fprintf(stderr,
+			(void)fprintf(stdout,
 			    "\nUNEXPECTED SOFT UPDATE INCONSISTENCY\n");
 		/*
 		 * Force foreground fsck to clean up inconsistency.
@@ -659,7 +661,7 @@ pfatal(fmt, va_alist)
 			if (sysctlbyname("vfs.ffs.setflags", 0, 0,
 			    &cmd, sizeof cmd) == -1)
 				pwarn("CANNOT SET FS_NEEDSFSCK FLAG\n");
-			fprintf(stderr, "CANNOT RUN IN BACKGROUND\n");
+			fprintf(stdout, "CANNOT RUN IN BACKGROUND\n");
 			ckfini(0);
 			exit(EEXIT);
 		}
@@ -667,9 +669,9 @@ pfatal(fmt, va_alist)
 	}
 	if (cdevname == NULL)
 		cdevname = "fsck";
-	(void)fprintf(stderr, "%s: ", cdevname);
-	(void)vfprintf(stderr, fmt, ap);
-	(void)fprintf(stderr,
+	(void)fprintf(stdout, "%s: ", cdevname);
+	(void)vfprintf(stdout, fmt, ap);
+	(void)fprintf(stdout,
 	    "\n%s: UNEXPECTED%sINCONSISTENCY; RUN fsck MANUALLY.\n",
 	    cdevname, usedsoftdep ? " SOFT UPDATE " : " ");
 	/*
@@ -706,8 +708,8 @@ pwarn(fmt, va_alist)
 	va_start(ap);
 #endif
 	if (preen)
-		(void)fprintf(stderr, "%s: ", cdevname);
-	(void)vfprintf(stderr, fmt, ap);
+		(void)fprintf(stdout, "%s: ", cdevname);
+	(void)vfprintf(stdout, fmt, ap);
 	va_end(ap);
 }
 
@@ -730,7 +732,7 @@ panic(fmt, va_alist)
 	va_start(ap);
 #endif
 	pfatal("INTERNAL INCONSISTENCY:");
-	(void)vfprintf(stderr, fmt, ap);
+	(void)vfprintf(stdout, fmt, ap);
 	va_end(ap);
 	exit(EEXIT);
 }

sbin/fsck_ffs/main.c

@@ -63,8 +63,6 @@ static const char rcsid[] =
 
 #include "fsck.h"
 
-int returntosingle;
-
 static void usage __P((void));
 static int argtoi __P((int flag, char *req, char *str, int base));
 static int docheck __P((struct fstab *fsp));
@@ -84,7 +82,7 @@ main(argc, argv)
 
 	sync();
 	skipclean = 1;
-	while ((ch = getopt(argc, argv, "b:Bc:dfm:npy")) != -1) {
+	while ((ch = getopt(argc, argv, "b:Bc:dfFm:npy")) != -1) {
 		switch (ch) {
 		case 'b':
 			skipclean = 0;
@@ -109,6 +107,10 @@ main(argc, argv)
 			skipclean = 0;
 			break;
 
+		case 'F':
+			bkgrdcheck = 1;
+			break;
+
 		case 'm':
 			lfmode = argtoi('m', "mode", optarg, 8);
 			if (lfmode &~ 07777)
@@ -154,7 +156,7 @@ main(argc, argv)
 		(void)setrlimit(RLIMIT_DATA, &rlimit);
 	}
 	while (argc-- > 0)
-		(void)checkfilesys(blockcheck(*argv++), 0, 0L, 0);
+		(void)checkfilesys(*argv++, 0, 0L, 0);
 
 	if (returntosingle)
 		ret = 2;
@@ -193,15 +195,46 @@ checkfilesys(filesys, mntpt, auxdata, child)
 	struct zlncnt *zlnp;
 	ufs_daddr_t blks;
 	ufs_daddr_t files;
-	int cylno;
+	int cylno, size;
 
 	if (preen && child)
 		(void)signal(SIGQUIT, voidquit);
 	cdevname = filesys;
 	if (debug && preen)
 		pwarn("starting\n");
+	/*
+	 * Make best effort to get the disk name. Check first to see
+	 * if it is listed among the mounted filesystems. Failing that
+	 * check to see if it is listed in /etc/fstab.
+	 */
+	mntp = getmntpt(filesys);
+	if (mntp != NULL)
+		filesys = mntp->f_mntfromname;
+	else
+		filesys = blockcheck(filesys);
+	/*
+	 * If -F flag specified, check to see whether a background check
+	 * is possible and needed. If possible and needed, exit with
+	 * status zero. Otherwise exit with status non-zero. A non-zero
+	 * exit status will cause a foreground check to be run.
+	 */
 	sblock_init();
-
+	if (bkgrdcheck) {
+		if ((fsreadfd = open(filesys, O_RDONLY)) < 0 || readsb(0) == 0)
+			exit(3);	/* Cannot read superblock */
+		close(fsreadfd);
+		if (sblock.fs_flags & FS_NEEDSFSCK)
+			exit(4);	/* Earlier background failed */
+		if ((sblock.fs_flags & FS_DOSOFTDEP) == 0)
+			exit(5);	/* Not running soft updates */
+		size = MIBSIZE;
+		if (sysctlnametomib("vfs.ffs.adjrefcnt", adjrefcnt, &size) < 0)
+			exit(6);	/* Lacks kernel support */
+		if ((mntp == NULL && sblock.fs_clean == 1) ||
+		    (mntp != NULL && (sblock.fs_flags & FS_UNCLEAN) == 0))
+			exit(7);	/* Filesystem clean, report it now */
+		exit(0);
+	}
 	/*
 	 * If we are to do a background check:
 	 *	Get the mount point information of the filesystem
@@ -209,7 +242,6 @@ checkfilesys(filesys, mntpt, auxdata, child)
 	 *	return created snapshot file
 	 *	if not found, clear bkgrdflag and proceed with normal fsck
 	 */
-	mntp = getmntpt(filesys);
 	if (bkgrdflag) {
 		if (mntp == NULL) {
 			bkgrdflag = 0;
@@ -432,7 +464,7 @@ checkfilesys(filesys, mntpt, auxdata, child)
 }
 
 /*
- * Get the directory that the device is mounted on.
+ * Get the mount point information for name.
  */
 static struct statfs *
 getmntpt(name)
@@ -441,27 +473,35 @@ getmntpt(name)
 	struct stat devstat, mntdevstat;
 	char device[sizeof(_PATH_DEV) - 1 + MNAMELEN];
 	char *devname;
-	struct statfs *mntbuf;
-	int i, mntsize;
+	struct statfs *mntbuf, *statfsp;
+	int i, mntsize, isdev;
 
-	if (stat(name, &devstat) != 0 ||
-	    !(S_ISCHR(devstat.st_mode) || S_ISBLK(devstat.st_mode)))
+	if (stat(name, &devstat) != 0)
 		return (NULL);
+	if (S_ISCHR(devstat.st_mode) || S_ISBLK(devstat.st_mode))
+		isdev = 1;
+	else
+		isdev = 0;
 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
 	for (i = 0; i < mntsize; i++) {
-		if (strcmp(mntbuf[i].f_fstypename, "ufs") != 0)
-			continue;
-		devname = mntbuf[i].f_mntfromname;
+		statfsp = &mntbuf[i];
+		devname = statfsp->f_mntfromname;
 		if (*devname != '/') {
 			strcpy(device, _PATH_DEV);
 			strcat(device, devname);
-			devname = device;
+			strcpy(statfsp->f_mntfromname, device);
+		}
+		if (isdev == 0) {
+			if (strcmp(name, statfsp->f_mntonname))
+				continue;
+			return (statfsp);
 		}
 		if (stat(devname, &mntdevstat) == 0 &&
 		    mntdevstat.st_rdev == devstat.st_rdev)
-			return (&mntbuf[i]);
+			return (statfsp);
 	}
-	return (NULL);
+	statfsp = NULL;
+	return (statfsp);
 }
 
 static void

sbin/fsck_ffs/utilities.c

@@ -52,6 +52,7 @@ static const char rcsid[] =
 #include <string.h>
 #include <ctype.h>
 #include <fstab.h>
+#include <paths.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -64,11 +65,20 @@ blockcheck(origname)
 	char *origname;
 {
 	struct stat stslash, stblock, stchar;
-	char *newname, *raw;
+	char *newname, *raw, *cp;
 	struct fstab *fsinfo;
 	int retried = 0, len;
+	static char device[MAXPATHLEN];
 
 	newname = origname;
+	if (stat(newname, &stblock) < 0) {
+		cp = strrchr(newname, '/');
+		if (cp == 0) {
+			(void)snprintf(device, sizeof(device), "%s%s",
+				_PATH_DEV, newname);
+			newname = device;
+		}
+	}
 retry:
 	if (stat(newname, &stblock) < 0) {
 		printf("Can't stat %s: %s\n", newname, strerror(errno));
@@ -90,7 +100,7 @@ blockcheck(origname)
 			printf(
 			    "Can't resolve %s to character special device.\n",
 			    origname);
-			return (0);
+			return (origname);
 		}
 		newname = fsinfo->fs_spec;
 		retried++;