debugfs: teach the dx_hash command the -v option

Add an option for dx_hash to print more details about the hash
algorithm and hash seed to calculate the directory hash value.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

2 files changed, 30 insertions, 5 deletions

diff --git a/debugfs/debugfs.8.in b/debugfs/debugfs.8.in
index 5b5329c38..7cf5c1659 100644
--- a/debugfs/debugfs.8.in
+++ b/debugfs/debugfs.8.in
@@ -268,9 +268,24 @@ number, otherwise use the
 .B s_mmp_block
 field in the superblock to locate and use the existing MMP block.
 .TP
-.BI dx_hash " [-h hash_alg] [-s hash_seed] filename"
+.BI dx_hash " [-cv] [-h hash_alg] [-s hash_seed] filename"
 Calculate the directory hash of
 .IR filename .
+The
+.I -c
+option will casefold the filename before calculating the hash.  The
+.I -v
+option will make the
+.B dx_hash
+command more verbose and print the hash algorithm and hash seed to
+calculate the hash.
+If a file system is open, use the hash_seed and
+default hash_algorithm used by the file system, although these can be
+overridden by the
+.I -h
+and
+.I -s
+options.
 The hash algorithm specified with
 .I -h
 may be
diff --git a/debugfs/htree.c b/debugfs/htree.c
index a3e95ddb0..fab04e2b3 100644
--- a/debugfs/htree.c
+++ b/debugfs/htree.c
@@ -334,7 +334,7 @@ void do_dx_hash(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
 {
 	ext2_dirhash_t hash, minor_hash;
 	errcode_t	err;
-	int		c;
+	int		c, verbose = 0;
 	int		hash_version = 0;
 	__u32		hash_seed[4] = { 0, };
 	int		hash_flags = 0;
@@ -350,7 +350,7 @@ void do_dx_hash(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
 	}
 
 	reset_getopt();
-	while ((c = getopt(argc, argv, "h:s:ce:")) != EOF) {
+	while ((c = getopt(argc, argv, "h:s:ce:v")) != EOF) {
 		switch (c) {
 		case 'h':
 			hash_version = e2p_string2hash(optarg);
@@ -375,14 +375,17 @@ void do_dx_hash(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
 				return;
 			}
 			break;
+		case 'v':
+			verbose = 1;
+			break;
 		default:
 			goto print_usage;
 		}
 	}
 	if (optind != argc-1) {
 	print_usage:
-		com_err(argv[0], 0, "usage: dx_hash [-h hash_alg] "
-			"[-s hash_seed] [-c] [-e encoding] filename");
+		com_err(argv[0], 0, "usage: dx_hash [-cv] [-h hash_alg] "
+			"[-s hash_seed] [-e encoding] filename");
 		return;
 	}
 	err = ext2fs_dirhash2(hash_version, argv[optind],
@@ -395,6 +398,13 @@ void do_dx_hash(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
 	}
 	printf("Hash of %s is 0x%0x (minor 0x%0x)\n", argv[optind],
 	       hash, minor_hash);
+	if (verbose) {
+		char uuid_str[37];
+
+		uuid_unparse((__u8 *) hash_seed, uuid_str);
+		printf("  using hash algorithm %d and hash_seed %s\n",
+		       hash_version, uuid_str);
+	}
 }
 
 /*