Add SIGINT and SIGTERM handling to fsck and e2fsck. For e2fsck,

make sure we gracefully clean up and only exit at safe points.
For fsck, we pass the SIGINT/SIGTERM signal to the child processes,
so they can do their own cleanup.

10 files changed, 128 insertions, 16 deletions

diff --git a/e2fsck/ChangeLog b/e2fsck/ChangeLog
index aaf77636..132fcdf6 100644
--- a/e2fsck/ChangeLog
+++ b/e2fsck/ChangeLog
@@ -1,3 +1,20 @@
+2002-07-21  Theodore Ts'o  <tytso@mit.edu>
+
+	* e2fsck.8.in: Document new exit code FSCK_CANCELED
+
+	* unix.c (PRS, signal_cancel): Capture SIGINT and SIGTERM signals
+		and set a flag in the e2fsck context indicating that
+		cancellation has been requested, so that e2fsck will exit
+		only at safe points.
+		(main): Change the exit handling so that if a cancellation
+		is requested, return FSCK_CANCELED (a new exit code 32).
+		e2fsck can now return more than one exit code as part of a
+		bitmask (as had been documented in the man page).
+
+	* pass2.c (e2fsck_pass2, check_dir_block), pass3.c (e2fsck_pass3),
+		pass4.c (e2fsck_pass4): Check to see if a cancellation was
+		requested, and abort processing if necessary.
+
 2002-07-19  Theodore Ts'o  <tytso@mit.edu>
 
 	* rehash.c, Makefile.in: New file which rewrites directories using
diff --git a/e2fsck/e2fsck.8.in b/e2fsck/e2fsck.8.in
index ad517c12..57383f7a 100644
--- a/e2fsck/e2fsck.8.in
+++ b/e2fsck/e2fsck.8.in
@@ -214,7 +214,7 @@ is the sum of the following conditions:
 .br
 \	2\	\-\ File system errors corrected, system should
 .br
-\	\	\ \ be rebooted if file system was mounted
+\	\	\ \ be rebooted
 .br
 \	4\	\-\ File system errors left uncorrected
 .br
@@ -222,6 +222,8 @@ is the sum of the following conditions:
 .br
 \	16\	\-\ Usage or syntax error
 .br
+\	32\	\-\ E2fsck canceled by user request
+.br
 \	128\	\-\ Shared library error
 .br
 .SH SIGNALS
diff --git a/e2fsck/e2fsck.h b/e2fsck/e2fsck.h
index d68b79c1..c35bf684 100644
--- a/e2fsck/e2fsck.h
+++ b/e2fsck/e2fsck.h
@@ -58,6 +58,7 @@
 #define FSCK_UNCORRECTED 4	/* File system errors left uncorrected */
 #define FSCK_ERROR       8	/* Operational error */
 #define FSCK_USAGE       16	/* Usage or syntax error */
+#define FSCK_CANCELED	 32	/* Aborted with a signal or ^C */
 #define FSCK_LIBRARY     128	/* Shared library error */
 
 /*
diff --git a/e2fsck/pass2.c b/e2fsck/pass2.c
index db23c88e..1f484f45 100644
--- a/e2fsck/pass2.c
+++ b/e2fsck/pass2.c
@@ -148,6 +148,8 @@ void e2fsck_pass2(e2fsck_t ctx)
 
 #ifdef ENABLE_HTREE
 	for (i=0; (dx_dir = e2fsck_dx_dir_info_iter(ctx, &i)) != 0;) {
+		if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
+			return;
 		if (dx_dir->numblocks == 0)
 			continue;
 		clear_problem_context(&pctx);
@@ -565,9 +567,11 @@ static int check_dir_block(ext2_filsys fs,
 	buf = cd->buf;
 	ctx = cd->ctx;
 
-	if (ctx->progress)
-		if ((ctx->progress)(ctx, 2, cd->count++, cd->max))
-			return DIRENT_ABORT;
+	if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
+		return DIRENT_ABORT;
+	
+	if (ctx->progress && (ctx->progress)(ctx, 2, cd->count++, cd->max))
+		return DIRENT_ABORT;
 	
 	/*
 	 * Make sure the inode is still in use (could have been 
diff --git a/e2fsck/pass3.c b/e2fsck/pass3.c
index 7fdd8146..4b1f3970 100644
--- a/e2fsck/pass3.c
+++ b/e2fsck/pass3.c
@@ -110,9 +110,10 @@ void e2fsck_pass3(e2fsck_t ctx)
 			goto abort_exit;
 	
 	for (i=0; (dir = e2fsck_dir_info_iter(ctx, &i)) != 0;) {
-		if (ctx->progress)
-			if ((ctx->progress)(ctx, 3, count++, maxdirs))
-				goto abort_exit;
+		if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
+			goto abort_exit;
+		if (ctx->progress && (ctx->progress)(ctx, 3, count++, maxdirs))
+			goto abort_exit;
 		if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, dir->ino))
 			if (check_directory(ctx, dir, &pctx))
 				goto abort_exit;
diff --git a/e2fsck/pass4.c b/e2fsck/pass4.c
index 895b77ad..28c0996c 100644
--- a/e2fsck/pass4.c
+++ b/e2fsck/pass4.c
@@ -109,6 +109,8 @@ void e2fsck_pass4(e2fsck_t ctx)
 			return;
 	
 	for (i=1; i <= fs->super->s_inodes_count; i++) {
+		if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
+			return;
 		if ((i % fs->super->s_inodes_per_group) == 0) {
 			group++;
 			if (ctx->progress)
diff --git a/e2fsck/unix.c b/e2fsck/unix.c
index 18f2b2c7..7fca08c0 100644
--- a/e2fsck/unix.c
+++ b/e2fsck/unix.c
@@ -436,6 +436,16 @@ static void signal_progress_off(int sig)
 	e2fsck_clear_progbar(ctx);
 	ctx->progress = 0;
 }
+
+static void signal_cancel(int sig)
+{
+	e2fsck_t ctx = e2fsck_global_ctx;
+
+	if (!ctx)
+		exit(FSCK_CANCELED);
+
+	ctx->flags |= E2F_FLAG_CANCEL;
+}
 #endif
 
 static errcode_t PRS(int argc, char *argv[], e2fsck_t *ret_ctx)
@@ -632,6 +642,9 @@ static errcode_t PRS(int argc, char *argv[], e2fsck_t *ret_ctx)
 	sigaction(SIGUSR1, &sa, 0);
 	sa.sa_handler = signal_progress_off;
 	sigaction(SIGUSR2, &sa, 0);
+	sa.sa_handler = signal_cancel;
+	sigaction(SIGINT, &sa, 0);
+	sigaction(SIGTERM, &sa, 0);
 #endif
 
 	/* Update our PATH to include /sbin if we need to run badblocks  */
@@ -958,23 +971,26 @@ restart:
 		ext2fs_close(fs);
 		goto restart;
 	}
-	if (run_result & E2F_FLAG_SIGNAL_MASK)
-		fatal_error(ctx, 0);
-	if (run_result & E2F_FLAG_CANCEL)
-		ext2fs_unmark_valid(fs);
+	if (run_result & E2F_FLAG_CANCEL) {
+		printf(_("%s: e2fsck canceled.\n"), ctx->device_name ?
+		       ctx->device_name : ctx->filesystem_name);
+		exit_value |= FSCK_CANCELED;
+	}
+	if (run_result & E2F_FLAG_ABORT)
+		fatal_error(ctx, _("aborted"));
 
 #ifdef MTRACE
 	mtrace_print("Cleanup");
 #endif
 	if (ext2fs_test_changed(fs)) {
-		exit_value = FSCK_NONDESTRUCT;
+		exit_value |= FSCK_NONDESTRUCT;
 		if (!(ctx->options & E2F_OPT_PREEN))
 		    printf(_("\n%s: ***** FILE SYSTEM WAS MODIFIED *****\n"),
 			       ctx->device_name);
 		if (root_filesystem && !read_only_root) {
 			printf(_("%s: ***** REBOOT LINUX *****\n"),
 			       ctx->device_name);
-			exit_value = FSCK_REBOOT;
+			exit_value |= FSCK_REBOOT;
 		}
 	}
 	if (ext2fs_test_valid(fs))
@@ -982,12 +998,13 @@ restart:
 	else {
 		printf(_("\n%s: ********** WARNING: Filesystem still has "
 			 "errors **********\n\n"), ctx->device_name);
-		exit_value = FSCK_UNCORRECTED;
+		exit_value |= FSCK_UNCORRECTED;
+		exit_value &= ~FSCK_NONDESTRUCT;
 	}
 	if (!(ctx->options & E2F_OPT_READONLY)) {
 		if (ext2fs_test_valid(fs)) {
 			if (!(sb->s_state & EXT2_VALID_FS))
-				exit_value = FSCK_NONDESTRUCT;
+				exit_value |= FSCK_NONDESTRUCT;
 			sb->s_state = EXT2_VALID_FS;
 		} else
 			sb->s_state &= ~EXT2_VALID_FS;
@@ -995,7 +1012,10 @@ restart:
 		sb->s_lastcheck = time(NULL);
 		ext2fs_mark_super_dirty(fs);
 	}
-	show_stats(ctx);
+	if (exit_value & FSCK_CANCELED)
+		exit_value &= ~FSCK_NONDESTRUCT;
+	else
+		show_stats(ctx);
 
 	e2fsck_write_bitmaps(ctx);
 	
diff --git a/misc/ChangeLog b/misc/ChangeLog
index 6de1398a..0469b719 100644
--- a/misc/ChangeLog
+++ b/misc/ChangeLog
@@ -1,3 +1,10 @@
+2002-07-21  Theodore Ts'o  <tytso@mit.edu>
+
+	* fsck.8.in: Document new fsck exit code, FSCK_CANCELED.
+
+	* fsck.c: Trap SIGINT and SIGTERM, and relay it to all of the
+		child fsck processes.
+
 2002-07-14  Theodore Ts'o  <tytso@mit.edu>
 
 	* mke2fs.c (zap_sector): Clear the buffer *after* testing for the
diff --git a/misc/fsck.8.in b/misc/fsck.8.in
index fb205214..fd136ecc 100644
--- a/misc/fsck.8.in
+++ b/misc/fsck.8.in
@@ -49,6 +49,8 @@ is the sum of the following conditions:
 .br
 \	16\	\-\ Usage or syntax error
 .br
+\	32\	\-\ Fsck canceled by user request
+.br
 \	128\	\-\ Shared library error
 .br
 The exit code returned when all file systems are checked using the
diff --git a/misc/fsck.c b/misc/fsck.c
index 8c4499ef..8503eee4 100644
--- a/misc/fsck.c
+++ b/misc/fsck.c
@@ -100,6 +100,8 @@ int progress = 0;
 int force_all_parallel = 0;
 int num_running = 0;
 int max_running = 0;
+volatile int cancel_requested = 0;
+int kill_sent = 0;
 char *progname;
 char *fstype = NULL;
 struct fs_info *filesys_info;
@@ -468,6 +470,23 @@ static int execute(const char *type, char *device, char *mntpt,
 }
 
 /*
+ * Send a signal to all outstanding fsck child processes
+ */
+static int kill_all(int signal)
+{
+	struct fsck_instance *inst;
+	int	n = 0;
+
+	for (inst = instance_list; inst; inst = inst->next) {
+		if (inst->flags & FLAG_DONE)
+			continue;
+		kill(inst->pid, signal);
+		n++;
+	}
+	return n;
+}
+
+/*
  * Wait for one child process to exit; when it does, unlink it from
  * the list of executing child processes, and return it.
  */
@@ -502,6 +521,10 @@ static struct fsck_instance *wait_one(int flags)
 	
 	do {
 		pid = waitpid(-1, &status, flags);
+		if (cancel_requested && !kill_sent) {
+			kill_all(SIGTERM);
+			kill_sent++;
+		}
 		if ((pid == 0) && (flags & WNOHANG))
 			return NULL;
 		if (pid < 0) {
@@ -908,6 +931,8 @@ static int check_all(NOARGS)
 		pass_done = 1;
 
 		for (fs = filesys_info; fs; fs = fs->next) {
+			if (cancel_requested)
+				break;
 			if (fs->flags & FLAG_DONE)
 				continue;
 			/*
@@ -945,6 +970,8 @@ static int check_all(NOARGS)
 				break;
 			}
 		}
+		if (cancel_requested)
+			break;
 		if (verbose > 1)
 			printf(_("--waiting-- (pass %d)\n"), passno);
 		status |= wait_all(pass_done ? 0 : WNOHANG);
@@ -955,6 +982,10 @@ static int check_all(NOARGS)
 		} else
 			not_done_yet++;
 	}
+	if (cancel_requested && !kill_sent) {
+		kill_all(SIGTERM);
+		kill_sent++;
+	}
 	status |= wait_all(0);
 	return status;
 }
@@ -966,6 +997,13 @@ static void usage(NOARGS)
 	exit(EXIT_USAGE);
 }
 
+#ifdef HAVE_SIGNAL_H
+static void signal_cancel(int sig)
+{
+	cancel_requested++;
+}
+#endif
+
 static void PRS(int argc, char *argv[])
 {
 	int	i, j;
@@ -973,6 +1011,17 @@ static void PRS(int argc, char *argv[])
 	char	options[128];
 	int	opt = 0;
 	int     opts_for_fsck = 0;
+#ifdef HAVE_SIGNAL_H
+	struct sigaction	sa;
+
+	/*
+	 * Set up signal action
+	 */
+	memset(&sa, 0, sizeof(struct sigaction));
+	sa.sa_handler = signal_cancel;
+	sigaction(SIGINT, &sa, 0);
+	sigaction(SIGTERM, &sa, 0);
+#endif
 	
 	num_devices = 0;
 	num_args = 0;
@@ -1128,6 +1177,13 @@ int main(int argc, char *argv[])
 		exit(EXIT_ERROR);
 	}
 	for (i = 0 ; i < num_devices; i++) {
+		if (cancel_requested) {
+			if (!kill_sent) {
+				kill_all(SIGTERM);
+				kill_sent++;
+			}
+			break;
+		}
 		fsck_device(devices[i], interactive);
 		if (serialize || (num_running >= max_running)) {
 			struct fsck_instance *inst;