[JFFS2] Handle dirents on the flash with embedded zero bytes in names.

In three places: summary scan, normal scan, REF_PRISTINE GC.

Just truncate at the NUL, since that was the correct thing to do in the
only case where this (inexplicable) breakage has been seen.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 11 insertions, 4 deletions

diff --git a/fs/jffs2/scan.c b/fs/jffs2/scan.c
index 35ef8d83366..272872d27fd 100644
--- a/fs/jffs2/scan.c
+++ b/fs/jffs2/scan.c
@@ -1004,6 +1004,7 @@ static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblo
 {
 	struct jffs2_full_dirent *fd;
 	struct jffs2_inode_cache *ic;
+	uint32_t checkedlen;
 	uint32_t crc;
 	int err;
 
@@ -1024,12 +1025,18 @@ static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblo
 
 	pseudo_random += je32_to_cpu(rd->version);
 
-	fd = jffs2_alloc_full_dirent(rd->nsize+1);
+	/* Should never happen. Did. (OLPC trac #4184)*/
+	checkedlen = strnlen(rd->name, rd->nsize);
+	if (checkedlen < rd->nsize) {
+		printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n",
+		       ofs, checkedlen);
+	}
+	fd = jffs2_alloc_full_dirent(checkedlen+1);
 	if (!fd) {
 		return -ENOMEM;
 	}
-	memcpy(&fd->name, rd->name, rd->nsize);
-	fd->name[rd->nsize] = 0;
+	memcpy(&fd->name, rd->name, checkedlen);
+	fd->name[checkedlen] = 0;
 
 	crc = crc32(0, fd->name, rd->nsize);
 	if (crc != je32_to_cpu(rd->name_crc)) {
@@ -1055,7 +1062,7 @@ static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblo
 	fd->next = NULL;
 	fd->version = je32_to_cpu(rd->version);
 	fd->ino = je32_to_cpu(rd->ino);
-	fd->nhash = full_name_hash(fd->name, rd->nsize);
+	fd->nhash = full_name_hash(fd->name, checkedlen);
 	fd->type = rd->type;
 	jffs2_add_fd_to_list(c, fd, &ic->scan_dents);