commit f837169ab53dc915e10bdb480eaeb5bbb52c0c09
Author: Paul Evans <pevans@redhat.com>
Date:   Wed Mar 6 12:28:16 2024 +0000

    gfs2_edit: truncate to filesystem size at end of restoremeta()
    
    Truncate to metadata header's filesystem size at the end of restore if
    a header is present.
    
    Resolves: RHEL-26661
    
    Signed-off-by: Paul Evans <pevans@redhat.com>

diff --git a/gfs2/edit/savemeta.c b/gfs2/edit/savemeta.c
index 4ee76be0..f5448974 100644
--- a/gfs2/edit/savemeta.c
+++ b/gfs2/edit/savemeta.c
@@ -1327,9 +1327,8 @@ static void restoremeta_usage(void)
 	fprintf(stderr, "gfs2_edit restoremeta <metadata_file> <block_device>\n");
 }
 
-static int restore_init(const char *path, struct metafd *mfd, int printonly)
+static int restore_init(const char *path, struct metafd *mfd, struct savemeta *sm, int printonly)
 {
-	struct savemeta sm = {0};
 	struct gfs2_sb rsb;
 	uint16_t sb_siglen;
 	char *end;
@@ -1357,7 +1356,7 @@ static int restore_init(const char *path, struct metafd *mfd, int printonly)
 		return -1;
 	}
 	bp = restore_buf;
-	ret = parse_header(bp, &sm);
+	ret = parse_header(bp, sm);
 	if (ret == 0) {
 		bp = restore_buf + sizeof(struct savemeta_header);
 		restore_off = sizeof(struct savemeta_header);
@@ -1383,10 +1382,10 @@ static int restore_init(const char *path, struct metafd *mfd, int printonly)
 	if (ret != 0)
 		return ret;
 
-	if (sm.sm_fs_bytes > 0) {
-		sbd.fssize = sm.sm_fs_bytes / sbd.sd_bsize;
+	if (sm->sm_fs_bytes > 0) {
+		sbd.fssize = sm->sm_fs_bytes / sbd.sd_bsize;
 		printf("Saved file system size is %"PRIu64" blocks, %.2fGB\n",
-		       sbd.fssize, sm.sm_fs_bytes / ((float)(1 << 30)));
+		       sbd.fssize, sm->sm_fs_bytes / ((float)(1 << 30)));
 	}
 	printf("Block size is %uB\n", sbd.sd_bsize);
 	printf("This is gfs%c metadata.\n", sbd.gfs1 ? '1': '2');
@@ -1406,6 +1405,8 @@ static int restore_init(const char *path, struct metafd *mfd, int printonly)
 void restoremeta(const char *in_fn, const char *out_device, uint64_t printonly)
 {
 	struct metafd mfd = {0};
+	struct savemeta sm = {0};
+	struct stat st;
 	int error;
 
 	termlines = 0;
@@ -1430,7 +1431,7 @@ void restoremeta(const char *in_fn, const char *out_device, uint64_t printonly)
 				  optional block no */
 		printonly = check_keywords(out_device);
 
-	error = restore_init(in_fn, &mfd, printonly);
+	error = restore_init(in_fn, &mfd, &sm, printonly);
 	if (error != 0)
 		exit(error);
 
@@ -1440,6 +1441,23 @@ void restoremeta(const char *in_fn, const char *out_device, uint64_t printonly)
 	}
 
 	error = restore_data(sbd.device_fd, &mfd, printonly);
+
+	/* When there is a metadata header available, truncate to filesystem 
+	   size if our device_fd is a regular file */   
+	if (!printonly) {
+		if (fstat(sbd.device_fd, &st) == -1) {
+			fprintf(stderr, "Failed to stat %s: %s\n", out_device, strerror(errno));
+			error = errno;
+		}
+	
+		if (sm.sm_fs_bytes > 0 && S_ISREG(st.st_mode)) {
+			if (ftruncate(sbd.device_fd, sm.sm_fs_bytes) != 0) {
+				fprintf(stderr, "Failed to truncate: %s, %s\n", out_device, strerror(errno));
+				error = errno;
+			}
+		}
+	}
+
 	printf("File %s %s %s.\n", in_fn,
 	       (printonly ? "print" : "restore"),
 	       (error ? "error" : "successful"));
diff --git a/tests/edit.at b/tests/edit.at
index d6795218..29835df0 100644
--- a/tests/edit.at
+++ b/tests/edit.at
@@ -61,3 +61,13 @@ AT_CHECK([$GFS_MKFS -p lock_nolock $GFS_TGT], 0, [ignore], [ignore])
 AT_CHECK([gfs2_edit savemeta -z0 $GFS_TGT /dev/null], 0, [ignore], [ignore])
 AT_CHECK([gfs2_edit savemeta $GFS_TGT /dev/null], 0, [ignore], [ignore])
 AT_CLEANUP
+
+AT_SETUP([Truncate on restoremeta])
+AT_KEYWORDS(gfs2_edit edit)
+GFS_TGT_REGEN
+AT_CHECK([$GFS_MKFS -p lock_nolock $GFS_TGT], 0, [ignore], [ignore])
+AT_CHECK([gfs2_edit savemeta $GFS_TGT test.meta], 0, [ignore], [ignore])
+AT_CHECK([truncate -s 10K test.file], 0, [ignore], [ignore])
+AT_CHECK([gfs2_edit restoremeta test.meta test.file], 0, [ignore], [ignore])
+AT_CHECK([fsck.gfs2 -n test.file], 0, [ignore], [ignore])
+AT_CLEANUP