tune2fs: reset MMP state on error exit

If tune2fs cannot perform the requested change, ensure that the MMP
block is reset to the unused state before exiting.  Otherwise, the
filesystem will be left with mmp_seq = EXT4_MMP_SEQ_FSCK set, which
prevents it from being mounted afterward:

    EXT4-fs warning (device dm-9): ext4_multi_mount_protect:311:
        fsck is running on the filesystem

Add a test to try some failed tune2fs operations and verify that the
MMP block is left in a clean state afterward.

Lustre-bug-id: https://jira.whamcloud.com/browse/LU-13672
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 48 insertions, 36 deletions

diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index 39cf8587..a481d8f3 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -423,7 +423,7 @@ static int update_mntopts(ext2_filsys fs, char *mntopts)
 	return 0;
 }
 
-static void check_fsck_needed(ext2_filsys fs, const char *prompt)
+static int check_fsck_needed(ext2_filsys fs, const char *prompt)
 {
 	/* Refuse to modify anything but a freshly checked valid filesystem. */
 	if (!(fs->super->s_state & EXT2_VALID_FS) ||
@@ -433,15 +433,17 @@ static void check_fsck_needed(ext2_filsys fs, const char *prompt)
 		puts(_(please_fsck));
 		if (mount_flags & EXT2_MF_READONLY)
 			printf("%s", _("(and reboot afterwards!)\n"));
-		exit(1);
+		return 1;
 	}
 
 	/* Give the admin a few seconds to bail out of a dangerous op. */
 	if (!getenv("TUNE2FS_FORCE_PROMPT") && (!isatty(0) || !isatty(1)))
-		return;
+		return 0;
 
 	puts(prompt);
 	proceed_question(5);
+
+	return 0;
 }
 
 static void request_dir_fsck_afterwards(ext2_filsys fs)
@@ -1224,12 +1226,13 @@ mmp_error:
 
 	if (FEATURE_ON(E2P_FEATURE_RO_INCOMPAT,
 		       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
-		check_fsck_needed(fs,
-			_("Enabling checksums could take some time."));
+		if (check_fsck_needed(fs,
+			_("Enabling checksums could take some time.")))
+			return 1;
 		if (mount_flags & EXT2_MF_MOUNTED) {
 			fputs(_("Cannot enable metadata_csum on a mounted "
 				"filesystem!\n"), stderr);
-			exit(1);
+			return 1;
 		}
 		if (!ext2fs_has_feature_extents(fs->super))
 			printf("%s",
@@ -1265,12 +1268,13 @@ mmp_error:
 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
 		__u32	test_features[3];
 
-		check_fsck_needed(fs,
-			_("Disabling checksums could take some time."));
+		if (check_fsck_needed(fs,
+			_("Disabling checksums could take some time.")))
+			return 1;
 		if (mount_flags & EXT2_MF_MOUNTED) {
 			fputs(_("Cannot disable metadata_csum on a mounted "
 				"filesystem!\n"), stderr);
-			exit(1);
+			return 1;
 		}
 		rewrite_checksums = 1;
 
@@ -1311,7 +1315,7 @@ mmp_error:
 		if (mount_flags & EXT2_MF_MOUNTED) {
 			fputs(_("Cannot enable uninit_bg on a mounted "
 				"filesystem!\n"), stderr);
-			exit(1);
+			return 1;
 		}
 
 		/* Do not enable uninit_bg when metadata_csum enabled */
@@ -1326,7 +1330,7 @@ mmp_error:
 		if (mount_flags & EXT2_MF_MOUNTED) {
 			fputs(_("Cannot disable uninit_bg on a mounted "
 				"filesystem!\n"), stderr);
-			exit(1);
+			return 1;
 		}
 
 		err = disable_uninit_bg(fs,
@@ -1345,7 +1349,7 @@ mmp_error:
 		if (mount_flags & EXT2_MF_MOUNTED) {
 			fprintf(stderr, _("Cannot enable 64-bit mode "
 					  "while mounted!\n"));
-			exit(1);
+			return 1;
 		}
 		ext2fs_clear_feature_64bit(sb);
 		feature_64bit = 1;
@@ -1355,7 +1359,7 @@ mmp_error:
 		if (mount_flags & EXT2_MF_MOUNTED) {
 			fprintf(stderr, _("Cannot disable 64-bit mode "
 					  "while mounted!\n"));
-			exit(1);
+			return 1;
 		}
 		ext2fs_set_feature_64bit(sb);
 		feature_64bit = -1;
@@ -1385,7 +1389,7 @@ mmp_error:
 		if (fs->super->s_inode_size == EXT2_GOOD_OLD_INODE_SIZE) {
 			fprintf(stderr, _("Cannot enable project feature; "
 					  "inode size too small.\n"));
-			exit(1);
+			return 1;
 		}
 		Q_flag = 1;
 		quota_enable[PRJQUOTA] = QOPT_ENABLE;
@@ -1452,8 +1456,9 @@ mmp_error:
 				      stderr);
 				return 1;
 			}
-			check_fsck_needed(fs, _("Recalculating checksums "
-						"could take some time."));
+			if (check_fsck_needed(fs, _("Recalculating checksums "
+						     "could take some time.")))
+				return 1;
 			rewrite_checksums = 1;
 		}
 	}
@@ -1566,7 +1571,7 @@ err:
 	return 1;
 }
 
-static void handle_quota_options(ext2_filsys fs)
+static int handle_quota_options(ext2_filsys fs)
 {
 	errcode_t retval;
 	quota_ctx_t qctx;
@@ -1580,13 +1585,13 @@ static void handle_quota_options(ext2_filsys fs)
 			break;
 	if (qtype == MAXQUOTAS)
 		/* Nothing to do. */
-		return;
+		return 0;
 
 	if (quota_enable[PRJQUOTA] == QOPT_ENABLE &&
 	    fs->super->s_inode_size == EXT2_GOOD_OLD_INODE_SIZE) {
 		fprintf(stderr, _("Cannot enable project quota; "
 				  "inode size too small.\n"));
-		exit(1);
+		return 1;
 	}
 
 	for (qtype = 0; qtype < MAXQUOTAS; qtype++) {
@@ -1598,7 +1603,7 @@ static void handle_quota_options(ext2_filsys fs)
 	if (retval) {
 		com_err(program_name, retval,
 			_("while initializing quota context in support library"));
-		exit(1);
+		return 1;
 	}
 
 	if (qtype_bits)
@@ -1614,7 +1619,7 @@ static void handle_quota_options(ext2_filsys fs)
 					com_err(program_name, retval,
 						_("while updating quota limits (%d)"),
 						qtype);
-					exit(1);
+					return 1;
 				}
 			}
 			retval = quota_write_inode(qctx, 1 << qtype);
@@ -1622,7 +1627,7 @@ static void handle_quota_options(ext2_filsys fs)
 				com_err(program_name, retval,
 					_("while writing quota file (%d)"),
 					qtype);
-				exit(1);
+				return 1;
 			}
 			/* Enable Quota feature if one of quota enabled */
 			if (!ext2fs_has_feature_quota(fs->super)) {
@@ -1640,7 +1645,7 @@ static void handle_quota_options(ext2_filsys fs)
 				com_err(program_name, retval,
 					_("while removing quota file (%d)"),
 					qtype);
-				exit(1);
+				return 1;
 			}
 			if (qtype == PRJQUOTA) {
 				ext2fs_clear_feature_project(fs->super);
@@ -1663,7 +1668,7 @@ static void handle_quota_options(ext2_filsys fs)
 	}
 	if (need_dirty)
 		ext2fs_mark_super_dirty(fs);
-	return;
+	return 0;
 }
 
 static int option_handle_function(char *token)
@@ -2958,8 +2963,10 @@ retry_open:
 			rc = 1;
 			goto closefs;
 		}
-		check_fsck_needed(fs,
+		rc = check_fsck_needed(fs,
 			_("Resizing inodes could take some time."));
+		if (rc)
+			goto closefs;
 		/*
 		 * If inode resize is requested use the
 		 * Undo I/O manager
@@ -3015,16 +3022,16 @@ _("Warning: The journal is dirty. You may wish to replay the journal like:\n\n"
 	/* Recover the journal if possible. */
 	if ((open_flag & EXT2_FLAG_RW) && !(mount_flags & (EXT2_MF_BUSY | EXT2_MF_MOUNTED)) &&
 	    ext2fs_has_feature_journal_needs_recovery(fs->super)) {
-		errcode_t err;
-
 		printf(_("Recovering journal.\n"));
-		err = ext2fs_run_ext3_journal(&fs);
-		if (err) {
-			com_err("tune2fs", err, "while recovering journal.\n");
+		retval = ext2fs_run_ext3_journal(&fs);
+		if (retval) {
+			com_err("tune2fs", retval,
+				"while recovering journal.\n");
 			printf(_("Please run e2fsck -fy %s.\n"), argv[1]);
 			if (fs)
 				ext2fs_close_free(&fs);
-			exit(1);
+			rc = 1;
+			goto closefs;
 		}
 		sb = fs->super;
 	}
@@ -3128,13 +3135,13 @@ _("Warning: The journal is dirty. You may wish to replay the journal like:\n\n"
 			fputs(_("Warning: label too long, truncating.\n"),
 			      stderr);
 		memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
-		strncpy(sb->s_volume_name, new_label,
+		strncpy((char *)sb->s_volume_name, new_label,
 			sizeof(sb->s_volume_name));
 		ext2fs_mark_super_dirty(fs);
 	}
 	if (M_flag) {
 		memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
-		strncpy(sb->s_last_mounted, new_last_mounted,
+		strncpy((char *)sb->s_last_mounted, new_last_mounted,
 			sizeof(sb->s_last_mounted));
 		ext2fs_mark_super_dirty(fs);
 	}
@@ -3176,7 +3183,9 @@ _("Warning: The journal is dirty. You may wish to replay the journal like:\n\n"
 			rc = 1;
 			goto closefs;
 		}
-		handle_quota_options(fs);
+		rc = handle_quota_options(fs);
+		if (rc)
+			goto closefs;
 	}
 
 	if (U_flag) {
@@ -3188,9 +3197,11 @@ _("Warning: The journal is dirty. You may wish to replay the journal like:\n\n"
 		if (!ext2fs_has_feature_csum_seed(fs->super) &&
 		    (ext2fs_has_feature_metadata_csum(fs->super) ||
 		     ext2fs_has_feature_ea_inode(fs->super))) {
-			check_fsck_needed(fs,
+			rc = check_fsck_needed(fs,
 				_("Setting the UUID on this "
 				  "filesystem could take some time."));
+			if (rc)
+				goto closefs;
 			rewrite_checksums = 1;
 		}
 
@@ -3212,7 +3223,8 @@ _("Warning: The journal is dirty. You may wish to replay the journal like:\n\n"
 					"metadata_csum_seed' and re-run this "
 					"command.\n"), stderr);
 				try_confirm_csum_seed_support();
-				exit(1);
+				rc = 1;
+				goto closefs;
 			}
 
 			/*