From e0b8ab86f00c7baaf335d831eb31e7499e5afd8b Mon Sep 17 00:00:00 2001
From: msvamp <51392775+msvamp@users.noreply.github.com>
Date: Sun, 8 Dec 2024 23:46:19 +0530
Subject: [PATCH] block: try to load fsck program from internal overlay

When extroot is mounted using config in internal overlay, it is very
likely that the fsck program is also installed on the same filesystem.
So we will try to execute it from the overlay if it is present, else
fallback to previous behaviour of finding it on rootfs mounted on /.

Signed-off-by: Manas Sambhus <manas.sambhus+github@gmail.com>
---
 block.c | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/block.c b/block.c
index 37f5bfb..5e7cb04 100644
--- a/block.c
+++ b/block.c
@@ -758,7 +758,7 @@ static int print_block_info(struct probe_info *pr)
 	return 0;
 }
 
-static void check_filesystem(struct probe_info *pr)
+static void check_filesystem(struct probe_info *pr, char *overlay)
 {
 	pid_t pid;
 	struct stat statbuf;
@@ -767,27 +767,44 @@ static void check_filesystem(struct probe_info *pr)
 	const char *fatfsck = "/usr/sbin/fsck.fat";
 	const char *btrfsck = "/usr/bin/btrfsck";
 	const char *ntfsck = "/usr/bin/ntfsfix";
-	const char *ckfs;
+	const char *fsck;
+	char ckfs[64];
+	char ld_lib[32];
 
 	/* UBIFS does not need stuff like fsck */
 	if (!strncmp(pr->type, "ubifs", 5))
 		return;
 
 	if (!strncmp(pr->type, "vfat", 4)) {
-		ckfs = fatfsck;
+		fsck = fatfsck;
 	} else if (!strncmp(pr->type, "f2fs", 4)) {
-		ckfs = f2fsck;
+		fsck = f2fsck;
 	} else if (!strncmp(pr->type, "ext", 3)) {
-		ckfs = e2fsck;
+		fsck = e2fsck;
 	} else if (!strncmp(pr->type, "btrfs", 5)) {
-		ckfs = btrfsck;
+		fsck = btrfsck;
 	} else if (!strncmp(pr->type, "ntfs", 4)) {
-		ckfs = ntfsck;
+		fsck = ntfsck;
 	} else {
 		ULOG_ERR("check_filesystem: %s is not supported\n", pr->type);
 		return;
 	}
 
+	if (overlay) {
+		snprintf(ckfs, sizeof(ckfs), "%s/upper%s", overlay, fsck);
+		if (stat(ckfs, &statbuf) < 0) {
+			ULOG_WARN("check_filesystem: %s not found\n", ckfs);
+			strcpy(ckfs, fsck);
+		} else {
+			snprintf(ld_lib, sizeof(ld_lib), "%s/upper/usr/lib", overlay);
+			if (!stat(ld_lib, &statbuf) && S_ISDIR(statbuf.st_mode)) {
+				setenv("LD_LIBRARY_PATH", ld_lib, 1);
+			}
+		}
+	} else {
+		strcpy(ckfs, fsck);
+	}
+
 	if (stat(ckfs, &statbuf) < 0) {
 		ULOG_ERR("check_filesystem: %s not found\n", ckfs);
 		return;
@@ -1165,7 +1182,7 @@ static int mount_device(struct probe_info *pr, int type)
 	/* Mount the device */
 
 	if (check_fs)
-		check_filesystem(pr);
+		check_filesystem(pr, NULL);
 
 	mkdir_p(target, 0755);
 	if (!lstat(target, &st) && S_ISLNK(st.st_mode))
@@ -1608,7 +1625,7 @@ static int mount_extroot(char *cfg)
 		mkdir_p(path, 0755);
 
 		if (check_fs)
-			check_filesystem(pr);
+			check_filesystem(pr, cfg);
 
 		err = mount(pr->dev, path, pr->type, m->flags,
 		            (m->options) ? (m->options) : (""));