util-linux/util-linux-fsck-l-option.patch

fsck: add support for whole-disk locking (-l option)

This feature allows to call multiple independent fsck instances rather
than use only one "fsck -A" process.

The lock uses LOCK_EX flock(2). The lock request is ignored if the
whole-disk is non-rotating disk. The verbose mode (-V) provides
information about disk locking.

Note that "fsck -l" does not care if the device is stacked, for
example if you want to call "fsck -l /dev/md0" and "fsck -l /dev/md1"
then the underlying devices will not be locked. The traditional "fsck
-A" does not run in parallel for stacked devices.

http://pkgs.fedoraproject.org/gitweb/?p=util-linux-ng.git;a=commitdiff;h=6c69926dbfca8b07bd2f93b56bc8e7c54c7b227d#patch1

diff -up util-linux-ng-2.18/fsck/fsck.8.kzak util-linux-ng-2.18/fsck/fsck.8
--- util-linux-ng-2.18/fsck/fsck.8.kzak	2010-06-30 12:51:35.000000000 +0200
+++ util-linux-ng-2.18/fsck/fsck.8	2010-10-26 23:55:30.000000000 +0200
@@ -7,7 +7,7 @@
 fsck \- check and repair a Linux file system
 .SH SYNOPSIS
 .B fsck
-.RB [ \-sAVRTMNP ]
+.RB [ \-lsAVRTMNP ]
 .RB [ \-C
 .RI [ fd ]]
 .RB [ \-t
@@ -80,6 +80,17 @@ variable.  Please see the file system-sp
 further details.
 .SH OPTIONS
 .TP
+.B \-l
+Lock whole-disk device by exclusive
+.BR flock (2).
+This option can be used with one device only (e.g. -A and -l are mutually
+exclusive). This option is recommended when more
+.B fsck (8)
+instances are executed in the same time. The option is ignored when used for
+multiple devices or for non-rotating disk. The fsck does not lock underlying
+devices if executed to check stacked devices (e.g. MD or DM) -- this feature is
+not implemented yet.
+.TP
 .B \-s
 Serialize
 .B fsck
@@ -200,6 +211,11 @@ If there are multiple filesystems with t
 fsck will attempt to check them in parallel, although it will avoid running
 multiple filesystem checks on the same physical disk.
 .sp
+.B fsck
+does not check stacked devices (RAIDs, dm-crypt, ...) in parallel with any other
+device. See below for FSCK_FORCE_ALL_PARALLEL setting. The /sys filesystem is
+used to detemine dependencies between devices.
+.sp
 Hence, a very common configuration in
 .I /etc/fstab
 files is to set the root filesystem to have a
@@ -366,10 +382,10 @@ program's behavior is affected by the fo
 .B FSCK_FORCE_ALL_PARALLEL
 If this environment variable is set,
 .B fsck
-will attempt to run all of the specified filesystems in parallel,
-regardless of whether the filesystems appear to be on the same
-device.  (This is useful for RAID systems or high-end storage systems
-such as those sold by companies such as IBM or EMC.)
+will attempt to run all of the specified filesystems in parallel, regardless of
+whether the filesystems appear to be on the same device.  (This is useful for
+RAID systems or high-end storage systems such as those sold by companies such
+as IBM or EMC.) Note that the fs_passno value is still used.
 .TP
 .B FSCK_MAX_INST
 This environment variable will limit the maximum number of file system
diff -up util-linux-ng-2.18/fsck/fsck.c.kzak util-linux-ng-2.18/fsck/fsck.c
--- util-linux-ng-2.18/fsck/fsck.c.kzak	2010-05-19 23:36:23.000000000 +0200
+++ util-linux-ng-2.18/fsck/fsck.c	2010-10-26 23:55:30.000000000 +0200
@@ -31,6 +31,8 @@
 #include <sys/wait.h>
 #include <sys/signal.h>
 #include <sys/stat.h>
+#include <sys/file.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <stdio.h>
 #include <ctype.h>
@@ -42,6 +44,8 @@
 #include <errno.h>
 #include <malloc.h>
 #include <signal.h>
+#include <dirent.h>
+#include <blkid.h>
 
 #include "fsprobe.h"
 
@@ -85,6 +89,7 @@ char *devices[MAX_DEVICES];
 char *args[MAX_ARGS];
 int num_devices, num_args;
 
+int lockdisk = 0;
 int verbose = 0;
 int doall = 0;
 int noexecute = 0;
@@ -214,11 +219,97 @@ static void parse_escape(char *word)
 	*q = 0;
 }
 
+static dev_t get_disk(const char *device)
+{
+	struct stat st;
+	dev_t disk;
+
+	if (!stat(device, &st) &&
+	    !blkid_devno_to_wholedisk(st.st_rdev, NULL, 0, &disk))
+		return disk;
+
+	return 0;
+}
+
+static int is_irrotational_disk(dev_t disk)
+{
+	char path[PATH_MAX];
+	FILE *f;
+	int rc, x;
+
+	rc = snprintf(path, sizeof(path),
+			"/sys/dev/block/%d:%d/queue/rotational",
+			major(disk), minor(disk));
+
+	if (rc < 0 || rc + 1 > sizeof(path))
+		return 0;
+
+	f = fopen(path, "r");
+	if (!f)
+		return 0;
+
+	rc = fscanf(f, "%u", &x);
+	fclose(f);
+
+	return rc == 1 ? !x : 0;
+}
+
+static void lock_disk(struct fsck_instance *inst)
+{
+	dev_t disk = inst->fs->disk ? : get_disk(inst->fs->device);
+	char *diskname;
+
+	if (!disk || is_irrotational_disk(disk))
+		return;
+
+	diskname = blkid_devno_to_devname(disk);
+	if (!diskname)
+		return;
+
+	if (verbose)
+		printf(_("Locking disk %s ... "), diskname);
+
+	inst->lock = open(diskname, O_CLOEXEC | O_RDONLY);
+	if (inst->lock >= 0) {
+		int rc = -1;
+
+		/* inform users that we're waiting on the lock */
+		if (verbose &&
+		    (rc = flock(inst->lock, LOCK_EX | LOCK_NB)) != 0 &&
+		    errno == EWOULDBLOCK)
+			printf(_("(waiting) "));
+
+		if (rc != 0 && flock(inst->lock, LOCK_EX) != 0) {
+			close(inst->lock);			/* failed */
+			inst->lock = -1;
+		}
+	}
+
+	if (verbose)
+		printf("%s.\n", inst->lock >= 0 ? _("success") : _("failed"));
+
+	free(diskname);
+	return;
+}
+
+static void unlock_disk(struct fsck_instance *inst)
+{
+	if (inst->lock >= 0) {
+		/* explicitly unlock, don't rely on close(), maybe some library
+		 * (e.g. liblkid) has still open the device.
+		 */
+		flock(inst->lock, LOCK_UN);
+		close(inst->lock);
+	}
+}
+
+
+
 static void free_instance(struct fsck_instance *i)
 {
+	if (lockdisk)
+		unlock_disk(i);
 	free(i->prog);
-	free(i->device);
-	free(i->base_device);
 	free(i);
 	return;
 }
@@ -240,6 +331,8 @@ static struct fs_info *create_fs_device(
 	fs->passno = passno;
 	fs->flags = 0;
 	fs->next = NULL;
+	fs->disk = 0;
+	fs->stacked = 0;
 
 	if (!filesys_info)
 		filesys_info = fs;
@@ -414,8 +507,7 @@ static int progress_active(NOARGS)
  * Execute a particular fsck program, and link it into the list of
  * child processes we are waiting for.
  */
-static int execute(const char *type, const char *device, const char *mntpt,
-		   int interactive)
+static int execute(const char *type, struct fs_info *fs, int interactive)
 {
 	char *s, *argv[80], prog[80];
 	int  argc, i;
@@ -452,7 +544,7 @@ static int execute(const char *type, con
 		}
 	}
 
-	argv[argc++] = string_copy(device);
+	argv[argc++] = string_copy(fs->device);
 	argv[argc] = 0;
 
 	s = find_fsck(prog);
@@ -464,12 +556,19 @@ static int execute(const char *type, con
 
 	if (verbose || noexecute) {
 		printf("[%s (%d) -- %s] ", s, num_running,
-		       mntpt ? mntpt : device);
+		       fs->mountpt ? fs->mountpt : fs->device);
 		for (i=0; i < argc; i++)
 			printf("%s ", argv[i]);
 		printf("\n");
 	}
 
+
+	inst->fs = fs;
+	inst->lock = -1;
+
+	if (lockdisk)
+		lock_disk(inst);
+
 	/* Fork and execute the correct program. */
 	if (noexecute)
 		pid = -1;
@@ -492,8 +591,6 @@ static int execute(const char *type, con
 	inst->pid = pid;
 	inst->prog = string_copy(prog);
 	inst->type = string_copy(type);
-	inst->device = string_copy(device);
-	inst->base_device = base_device(device);
 	inst->start_time = time(0);
 	inst->next = NULL;
 
@@ -597,12 +694,12 @@ static struct fsck_instance *wait_one(in
 		} else {
 			printf(_("Warning... %s for device %s exited "
 			       "with signal %d.\n"),
-			       inst->prog, inst->device, sig);
+			       inst->prog, inst->fs->device, sig);
 			status = EXIT_ERROR;
 		}
 	} else {
 		printf(_("%s %s: status is %x, should never happen.\n"),
-		       inst->prog, inst->device, status);
+		       inst->prog, inst->fs->device, status);
 		status = EXIT_ERROR;
 	}
 	inst->exit_status = status;
@@ -641,7 +738,7 @@ ret_inst:
 		instance_list = inst->next;
 	if (verbose > 1)
 		printf(_("Finished with %s (exit status %d)\n"),
-		       inst->device, inst->exit_status);
+		       inst->fs->device, inst->exit_status);
 	num_running--;
 	return inst;
 }
@@ -698,7 +795,7 @@ static void fsck_device(struct fs_info *
 		type = DEFAULT_FSTYPE;
 
 	num_running++;
-	retval = execute(type, fs->device, fs->mountpt, interactive);
+	retval = execute(type, fs, interactive);
 	if (retval) {
 		fprintf(stderr, _("%s: Error %d while executing fsck.%s "
 			"for %s\n"), progname, retval, type, fs->device);
@@ -924,40 +1021,70 @@ static int ignore(struct fs_info *fs)
 	return 0;
 }
 
+static int count_slaves(dev_t disk)
+{
+	DIR *dir;
+	struct dirent *dp;
+	char dirname[PATH_MAX];
+	int count = 0;
+
+	snprintf(dirname, sizeof(dirname),
+			"/sys/dev/block/%u:%u/slaves/",
+			major(disk), minor(disk));
+
+	if (!(dir = opendir(dirname)))
+		return -1;
+
+	while ((dp = readdir(dir)) != 0) {
+#ifdef _DIRENT_HAVE_D_TYPE
+		if (dp->d_type != DT_UNKNOWN && dp->d_type != DT_LNK)
+			continue;
+#endif
+		if (dp->d_name[0] == '.' &&
+		    ((dp->d_name[1] == 0) ||
+		     ((dp->d_name[1] == '.') && (dp->d_name[2] == 0))))
+			continue;
+
+		count++;
+	}
+	closedir(dir);
+	return count;
+}
+
 /*
  * Returns TRUE if a partition on the same disk is already being
  * checked.
  */
-static int device_already_active(char *device)
+static int disk_already_active(struct fs_info *fs)
 {
 	struct fsck_instance *inst;
-	char *base;
 
 	if (force_all_parallel)
 		return 0;
 
-#ifdef BASE_MD
-	/* Don't check a soft raid disk with any other disk */
-	if (instance_list &&
-	    (!strncmp(instance_list->device, BASE_MD, sizeof(BASE_MD)-1) ||
-	     !strncmp(device, BASE_MD, sizeof(BASE_MD)-1)))
+	if (instance_list && instance_list->fs->stacked)
+		/* any instance for a stacked device is already running */
 		return 1;
-#endif
 
-	base = base_device(device);
+	if (!fs->disk) {
+		fs->disk = get_disk(fs->device);
+		if (fs->disk)
+			fs->stacked = count_slaves(fs->disk);
+	}
+
 	/*
 	 * If we don't know the base device, assume that the device is
 	 * already active if there are any fsck instances running.
+	 *
+	 * Don't check a stacked device with any other disk too.
 	 */
-	if (!base)
+	if (!fs->disk || fs->stacked)
 		return (instance_list != 0);
+
 	for (inst = instance_list; inst; inst = inst->next) {
-		if (!inst->base_device || !strcmp(base, inst->base_device)) {
-			free(base);
+		if (!inst->fs->disk || fs->disk == inst->fs->disk)
 			return 1;
-		}
 	}
-	free(base);
 	return 0;
 }
 
@@ -1038,7 +1165,7 @@ static int check_all(NOARGS)
 			 * already been spawned, then we need to defer
 			 * this to another pass.
 			 */
-			if (device_already_active(fs->device)) {
+			if (disk_already_active(fs)) {
 				pass_done = 0;
 				continue;
 			}
@@ -1188,6 +1315,9 @@ static void PRS(int argc, char *argv[])
 					}
 				}
 				break;
+			case 'l':
+				lockdisk++;
+				break;
 			case 'V':
 				verbose++;
 				break;
@@ -1298,6 +1428,12 @@ int main(int argc, char *argv[])
 	if ((num_devices == 1) || (serialize))
 		interactive = 1;
 
+	if (lockdisk && (doall || num_devices > 1)) {
+		fprintf(stderr, _("%s: the -l option can be used with one "
+				  "device only -- ignore\n"), progname);
+		lockdisk = 0;
+	}
+
 	/* If -A was specified ("check all"), do that! */
 	if (doall)
 		return check_all();
diff -up util-linux-ng-2.18/fsck/fsck.h.kzak util-linux-ng-2.18/fsck/fsck.h
--- util-linux-ng-2.18/fsck/fsck.h.kzak	2010-03-18 23:11:23.000000000 +0100
+++ util-linux-ng-2.18/fsck/fsck.h	2010-10-26 23:55:30.000000000 +0200
@@ -44,6 +44,8 @@ struct fs_info {
 	int   freq;
 	int   passno;
 	int   flags;
+	dev_t disk;
+	int   stacked;
 	struct fs_info *next;
 };
 
@@ -56,12 +58,12 @@ struct fs_info {
 struct fsck_instance {
 	int	pid;
 	int	flags;
+	int	lock;		/* flock()ed whole disk file descriptor or -1 */
 	int	exit_status;
 	time_t	start_time;
 	char *	prog;
 	char *	type;
-	char *	device;
-	char *	base_device;
+	struct fs_info *fs;
 	struct fsck_instance *next;
 };
 
diff -up util-linux-ng-2.18/fsck/Makefile.am.kzak util-linux-ng-2.18/fsck/Makefile.am
--- util-linux-ng-2.18/fsck/Makefile.am.kzak	2010-05-24 12:33:46.000000000 +0200
+++ util-linux-ng-2.18/fsck/Makefile.am	2010-10-26 23:55:30.000000000 +0200
@@ -3,7 +3,7 @@ include $(top_srcdir)/config/include-Mak
 sbin_PROGRAMS = fsck
 dist_man_MANS = fsck.8
 
-fsck_SOURCES = base_device.c fsck.c fsck.h $(top_srcdir)/lib/ismounted.c \
+fsck_SOURCES = fsck.c fsck.h $(top_srcdir)/lib/ismounted.c \
 	       $(top_srcdir)/lib/fsprobe.c $(top_srcdir)/lib/canonicalize.c
 fsck_LDADD =
 fsck_CFLAGS = $(AM_CFLAGS)
diff -up util-linux-ng-2.18/fsck/Makefile.in.kzak util-linux-ng-2.18/fsck/Makefile.in
--- util-linux-ng-2.18/fsck/Makefile.in.kzak	2010-10-26 23:56:04.000000000 +0200
+++ util-linux-ng-2.18/fsck/Makefile.in	2010-10-26 23:56:15.000000000 +0200
@@ -62,9 +62,8 @@ CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
 am__installdirs = "$(DESTDIR)$(sbindir)" "$(DESTDIR)$(man8dir)"
 PROGRAMS = $(sbin_PROGRAMS)
-am_fsck_OBJECTS = fsck-base_device.$(OBJEXT) fsck-fsck.$(OBJEXT) \
-	fsck-ismounted.$(OBJEXT) fsck-fsprobe.$(OBJEXT) \
-	fsck-canonicalize.$(OBJEXT)
+am_fsck_OBJECTS = fsck-fsck.$(OBJEXT) fsck-ismounted.$(OBJEXT) \
+	fsck-fsprobe.$(OBJEXT) fsck-canonicalize.$(OBJEXT)
 fsck_OBJECTS = $(am_fsck_OBJECTS)
 am__DEPENDENCIES_1 =
 @BUILD_LIBBLKID_FALSE@am__DEPENDENCIES_2 = $(am__DEPENDENCIES_1)
@@ -204,6 +203,7 @@ PACKAGE_BUGREPORT = @PACKAGE_BUGREPORT@
 PACKAGE_NAME = @PACKAGE_NAME@
 PACKAGE_STRING = @PACKAGE_STRING@
 PACKAGE_TARNAME = @PACKAGE_TARNAME@
+PACKAGE_URL = @PACKAGE_URL@
 PACKAGE_VERSION = @PACKAGE_VERSION@
 PATH_SEPARATOR = @PATH_SEPARATOR@
 PERL = @PERL@
@@ -315,7 +315,7 @@ ul_libmount_la = $(top_builddir)/shlibs/
 # mount.h is generated by ./configure script and stored in build directory
 ul_libmount_incdir = $(ul_libmount_builddir)
 dist_man_MANS = fsck.8
-fsck_SOURCES = base_device.c fsck.c fsck.h $(top_srcdir)/lib/ismounted.c \
+fsck_SOURCES = fsck.c fsck.h $(top_srcdir)/lib/ismounted.c \
 	       $(top_srcdir)/lib/fsprobe.c $(top_srcdir)/lib/canonicalize.c
 
 fsck_LDADD = $(am__append_1) $(am__append_3)
@@ -407,7 +407,6 @@ mostlyclean-compile:
 distclean-compile:
 	-rm -f *.tab.c
 
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/fsck-base_device.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/fsck-canonicalize.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/fsck-fsck.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/fsck-fsprobe.Po@am__quote@
@@ -437,22 +436,6 @@ distclean-compile:
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@	$(LTCOMPILE) -c -o $@ $<
 
-fsck-base_device.o: base_device.c
-@am__fastdepCC_TRUE@	$(AM_V_CC)$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(fsck_CFLAGS) $(CFLAGS) -MT fsck-base_device.o -MD -MP -MF $(DEPDIR)/fsck-base_device.Tpo -c -o fsck-base_device.o `test -f 'base_device.c' || echo '$(srcdir)/'`base_device.c
-@am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) $(DEPDIR)/fsck-base_device.Tpo $(DEPDIR)/fsck-base_device.Po
-@am__fastdepCC_FALSE@	$(AM_V_CC) @AM_BACKSLASH@
-@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='base_device.c' object='fsck-base_device.o' libtool=no @AMDEPBACKSLASH@
-@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
-@am__fastdepCC_FALSE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(fsck_CFLAGS) $(CFLAGS) -c -o fsck-base_device.o `test -f 'base_device.c' || echo '$(srcdir)/'`base_device.c
-
-fsck-base_device.obj: base_device.c
-@am__fastdepCC_TRUE@	$(AM_V_CC)$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(fsck_CFLAGS) $(CFLAGS) -MT fsck-base_device.obj -MD -MP -MF $(DEPDIR)/fsck-base_device.Tpo -c -o fsck-base_device.obj `if test -f 'base_device.c'; then $(CYGPATH_W) 'base_device.c'; else $(CYGPATH_W) '$(srcdir)/base_device.c'; fi`
-@am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) $(DEPDIR)/fsck-base_device.Tpo $(DEPDIR)/fsck-base_device.Po
-@am__fastdepCC_FALSE@	$(AM_V_CC) @AM_BACKSLASH@
-@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='base_device.c' object='fsck-base_device.obj' libtool=no @AMDEPBACKSLASH@
-@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
-@am__fastdepCC_FALSE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(fsck_CFLAGS) $(CFLAGS) -c -o fsck-base_device.obj `if test -f 'base_device.c'; then $(CYGPATH_W) 'base_device.c'; else $(CYGPATH_W) '$(srcdir)/base_device.c'; fi`
-
 fsck-fsck.o: fsck.c
 @am__fastdepCC_TRUE@	$(AM_V_CC)$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(fsck_CFLAGS) $(CFLAGS) -MT fsck-fsck.o -MD -MP -MF $(DEPDIR)/fsck-fsck.Tpo -c -o fsck-fsck.o `test -f 'fsck.c' || echo '$(srcdir)/'`fsck.c
 @am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) $(DEPDIR)/fsck-fsck.Tpo $(DEPDIR)/fsck-fsck.Po
diff -up util-linux-ng-2.18/Makefile.am.kzak util-linux-ng-2.18/Makefile.am
--- util-linux-ng-2.18/Makefile.am.kzak	2010-03-18 23:11:23.000000000 +0100
+++ util-linux-ng-2.18/Makefile.am	2010-10-26 23:55:30.000000000 +0200
@@ -30,8 +30,10 @@ SUBDIRS += mount
 endif
 
 if BUILD_FSCK
+if BUILD_LIBBLKID
 SUBDIRS += fsck
 endif
+endif
 
 ACLOCAL_AMFLAGS = -I m4