[PATCH 1/2 v3] xfs_repair: add flag -e to modify exit code for corrected errors

[Jan Tulak <jtulak@redhat.com>]

xfs_repair ends with a return code 0 if it finished ok, no matter if
there were some errors in the fs, or not. The new flag -e means that we
can avoid screenscraping and parsing text output to detect if an error
was found (and corrected).

If something could not be corrected or in any other case than the "found
something but fixed it all," the behaviour with this flag is unchanged.

Signed-off-by: Jan Tulak <jtulak@redhat.com>

---
v3:
- change the code from 3 to 4
- disallow -e -n combination
- change patch title
- minor man page edits

v2:
- edit man page changes
- report_corrected is now bool
- minor code simplification
---
 man/man8/xfs_repair.8 | 20 +++++++++++++++-----
 repair/xfs_repair.c   | 15 ++++++++++++++-
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/man/man8/xfs_repair.8 b/man/man8/xfs_repair.8
index 85e4dc97..19c13962 100644
--- a/man/man8/xfs_repair.8
+++ b/man/man8/xfs_repair.8
@@ -4,7 +4,7 @@ xfs_repair \- repair an XFS filesystem
 .SH SYNOPSIS
 .B xfs_repair
 [
-.B \-dfLnPv
+.B \-defLnPv
 ] [
 .B \-m
 .I maxmem
@@ -91,7 +91,9 @@ for a detailed description of the XFS realtime section.
 No modify mode. Specifies that
 .B xfs_repair
 should not modify the filesystem but should only scan the
-filesystem and indicate what repairs would have been made.
+filesystem and indicate what repairs would have been made. This option cannot
+be used together with
+.BR \-e .
 .TP
 .B \-P
 Disable prefetching of inode and directory blocks. Use this option if
@@ -168,6 +170,11 @@ Repair dangerously. Allow
 to repair an XFS filesystem mounted read only. This is typically done
 on a root filesystem from single user mode, immediately followed by a reboot.
 .TP
+.B \-e
+If any metadata corruption was repaired, the status returned is 4 instead of the
+usual 0. This option cannot be used together with
+.BR \-n .
+.TP
 .B \-V
 Prints the version number and exits.
 .SS Checks Performed
@@ -512,14 +519,17 @@ will return a status of 1 if filesystem corruption was detected and
 0 if no filesystem corruption was detected.
 .B xfs_repair
 run without the \-n option will always return a status code of 0 if
-it completes without problems.  If a runtime error is encountered
-during operation, it will return a status of 1.  In this case,
+it completes without problems, unless the flag
+.B -e
+is used. If it is used, then status 3 is reported when any issue with the
+filesystem was found, but could be fixed. If a runtime error is encountered during
+operation, it will return a status of 1. In this case,
 .B xfs_repair
 should be restarted.  If
 .B xfs_repair is unable
 to proceed due to a dirty log, it will return a status of 2.  See below.
 .SH DIRTY LOGS
-Due to the design of the XFS log, a dirty log can only be replayed 
+Due to the design of the XFS log, a dirty log can only be replayed
 by the kernel, on a machine having the same CPU architecture as the
 machine which was writing to the log.
 .B xfs_repair
diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
index 312a0d08..6bb8ea26 100644
--- a/repair/xfs_repair.c
+++ b/repair/xfs_repair.c
@@ -77,6 +77,7 @@ static char *c_opts[] = {
 static int	bhash_option_used;
 static long	max_mem_specified;	/* in megabytes */
 static int	phase2_threads = 32;
+static bool	report_corrected;
 
 static void
 usage(void)
@@ -90,6 +91,7 @@ usage(void)
 "  -l logdev    Specifies the device where the external log resides.\n"
 "  -m maxmem    Maximum amount of memory to be used in megabytes.\n"
 "  -n           No modify mode, just checks the filesystem for damage.\n"
+"               (Cannot be used together with -e.)\n"
 "  -P           Disables prefetching.\n"
 "  -r rtdev     Specifies the device where the realtime section resides.\n"
 "  -v           Verbose output.\n"
@@ -97,6 +99,8 @@ usage(void)
 "  -o subopts   Override default behaviour, refer to man page.\n"
 "  -t interval  Reporting interval in seconds.\n"
 "  -d           Repair dangerously.\n"
+"  -e           Exit with a non-zero code if any errors were repaired.\n"
+"               (Cannot be used together with -n.)\n"
 "  -V           Reports version and exits.\n"), progname);
 	exit(1);
 }
@@ -214,12 +218,13 @@ process_args(int argc, char **argv)
 	ag_stride = 0;
 	thread_count = 1;
 	report_interval = PROG_RPT_DEFAULT;
+	report_corrected = false;
 
 	/*
 	 * XXX have to add suboption processing here
 	 * attributes, quotas, nlinks, aligned_inos, sb_fbits
 	 */
-	while ((c = getopt(argc, argv, "c:o:fl:m:r:LnDvVdPt:")) != EOF)  {
+	while ((c = getopt(argc, argv, "c:o:fl:m:r:LnDvVdPet:")) != EOF)  {
 		switch (c) {
 		case 'D':
 			dumpcore = 1;
@@ -329,6 +334,9 @@ process_args(int argc, char **argv)
 		case 't':
 			report_interval = (int)strtol(optarg, NULL, 0);
 			break;
+		case 'e':
+			report_corrected = true;
+			break;
 		case '?':
 			usage();
 		}
@@ -339,6 +347,9 @@ process_args(int argc, char **argv)
 
 	if ((fs_name = argv[optind]) == NULL)
 		usage();
+
+	if (report_corrected && no_modify)
+		usage();
 }
 
 void __attribute__((noreturn))
@@ -1096,5 +1107,7 @@ _("Repair of readonly mount complete.  Immediate reboot encouraged.\n"));
 
 	free(msgbuf);
 
+	if (fs_is_dirty && report_corrected)
+		return (4);
 	return (0);
 }
-- 
2.16.2