For reproducible builds, it is necessary to control the random seed used
for hashing. Document the extended option for this feature.
Fixes: e1f71006 ("AOSP: mke2fs, libext2fs: make filesystem image reproducible")
Signed-off-by: Ralph Siemsen <ralph.siemsen@xxxxxxxxxx>
---
misc/mke2fs.8.in | 4 ++++
misc/mke2fs.c | 1 +
2 files changed, 5 insertions(+)
diff --git a/misc/mke2fs.8.in b/misc/mke2fs.8.in
index 13ddef47..14bae326 100644
--- a/misc/mke2fs.8.in
+++ b/misc/mke2fs.8.in
@@ -320,6 +320,10 @@ In the default configuration, the
.I strict
flag is disabled.
.TP
+.BI hash_seed= UUID
+Use the specified UUID as the seed for hashing, rather than generating a
+random seed each time. Intended for use with reproducible builds.
+.TP
.B lazy_itable_init\fR[\fB= \fI<0 to disable, 1 to enable>\fR]
If enabled and the uninit_bg feature is enabled, the inode table will
not be fully initialized by
diff --git a/misc/mke2fs.c b/misc/mke2fs.c
index 7f81a513..3a8ff5b1 100644
--- a/misc/mke2fs.c
+++ b/misc/mke2fs.c
@@ -1180,6 +1180,7 @@ static void parse_extended_opts(struct ext2_super_block *param,
"\trevision=<revision>\n"
"\tencoding=<encoding>\n"
"\tencoding_flags=<flags>\n"
+ "\thash_seed=<UUID for hash seed>\n"
"\tquotatype=<quota type(s) to be enabled>\n"
"\tassume_storage_prezeroed=<0 to disable, 1 to enable>\n\n"),
badopt ? badopt : "");
--
2.45.2.121.gc2b3f2b3cd
