[10/13] xfs_scrub: reduce size of struct name_entry

Commit Message

Darrick J. Wong Dec. 31, 2023, 10:47 p.m. UTC

From: Darrick J. Wong <[e-mail]>

libicu doesn't support processing strings longer than 2GB in length, and
we never feed the unicrash code a name longer than about 300 bytes.
Rearrange the structure to reduce the head structure size from 56 bytes
to 44 bytes.

Signed-off-by: Darrick J. Wong <[e-mail]>
---
 scrub/unicrash.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

Patch

diff --git a/scrub/unicrash.c b/scrub/unicrash.c
index 25f562b0a36..dfa798b09b0 100644
--- a/scrub/unicrash.c
+++ b/scrub/unicrash.c
@@ -57,18 +57,20 @@ 
  * In other words, skel = remove_invisible(nfd(remap_confusables(nfd(name)))).
  */
 
-typedef unsigned int __bitwise	badname_t;
+typedef uint16_t __bitwise	badname_t;
 
 struct name_entry {
 	struct name_entry	*next;
 
 	/* NFKC normalized name */
 	UChar			*normstr;
-	size_t			normstrlen;
 
 	/* Unicode skeletonized name */
 	UChar			*skelstr;
-	size_t			skelstrlen;
+
+	/* Lengths for normstr and skelstr */
+	int32_t			normstrlen;
+	int32_t			skelstrlen;
 
 	xfs_ino_t		ino;
 
@@ -76,7 +78,7 @@  struct name_entry {
 	badname_t		badflags;
 
 	/* Raw dirent name */
-	size_t			namelen;
+	uint16_t		namelen;
 	char			name[0];
 };
 #define NAME_ENTRY_SZ(nl)	(sizeof(struct name_entry) + 1 + \
@@ -343,6 +345,12 @@  name_entry_create(
 	struct name_entry	*new_entry;
 	size_t			namelen = strlen(name);
 
+	/* should never happen */
+	if (namelen > UINT16_MAX) {
+		ASSERT(namelen <= UINT16_MAX);
+		return false;
+	}
+
 	/* Create new entry */
 	new_entry = calloc(NAME_ENTRY_SZ(namelen), 1);
 	if (!new_entry)