openwrt/target/linux/generic/pending-5.4/532-jffs2_eofdetect.patch

From: Felix Fietkau <nbd@nbd.name>
Subject: fs: jffs2: EOF marker

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 fs/jffs2/build.c | 10 ++++++++++
 fs/jffs2/scan.c  | 21 +++++++++++++++++++--
 2 files changed, 29 insertions(+), 2 deletions(-)

--- a/fs/jffs2/build.c
+++ b/fs/jffs2/build.c
@@ -117,6 +117,16 @@ static int jffs2_build_filesystem(struct
 	dbg_fsbuild("scanned flash completely\n");
 	jffs2_dbg_dump_block_lists_nolock(c);
 
+	if (c->flags & (1 << 7)) {
+		printk("%s(): unlocking the mtd device... ", __func__);
+		mtd_unlock(c->mtd, 0, c->mtd->size);
+		printk("done.\n");
+
+		printk("%s(): erasing all blocks after the end marker... ", __func__);
+		jffs2_erase_pending_blocks(c, -1);
+		printk("done.\n");
+	}
+
 	dbg_fsbuild("pass 1 starting\n");
 	c->flags |= JFFS2_SB_FLAG_BUILDING;
 	/* Now scan the directory tree, increasing nlink according to every dirent found. */
--- a/fs/jffs2/scan.c
+++ b/fs/jffs2/scan.c
@@ -148,8 +148,14 @@ int jffs2_scan_medium(struct jffs2_sb_in
 		/* reset summary info for next eraseblock scan */
 		jffs2_sum_reset_collected(s);
 
-		ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
-						buf_size, s);
+		if (c->flags & (1 << 7)) {
+			if (mtd_block_isbad(c->mtd, jeb->offset))
+				ret = BLK_STATE_BADBLOCK;
+			else
+				ret = BLK_STATE_ALLFF;
+		} else
+			ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
+							buf_size, s);
 
 		if (ret < 0)
 			goto out;
@@ -564,6 +570,17 @@ full_scan:
 			return err;
 	}
 
+	if ((buf[0] == 0xde) &&
+		(buf[1] == 0xad) &&
+		(buf[2] == 0xc0) &&
+		(buf[3] == 0xde)) {
+		/* end of filesystem. erase everything after this point */
+		printk("%s(): End of filesystem marker found at 0x%x\n", __func__, jeb->offset);
+		c->flags |= (1 << 7);
+
+		return BLK_STATE_ALLFF;
+	}
+
 	/* We temporarily use 'ofs' as a pointer into the buffer/jeb */
 	ofs = 0;
 	max_ofs = EMPTY_SCAN_SIZE(c->sector_size);