There are some features (gdt_csum, 64bit, bg_use_meta_csum) that help
metadata_csum to work optimally. Print a warning if the user tries to create a
filesystem without those features.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
misc/mke2fs.c | 35 ++++++++++++++++++++++++++++++++++-
1 files changed, 34 insertions(+), 1 deletions(-)
diff --git a/misc/mke2fs.c b/misc/mke2fs.c
index ba7625d..c07c468 100644
--- a/misc/mke2fs.c
+++ b/misc/mke2fs.c
@@ -884,7 +884,8 @@ static __u32 ok_features[3] = {
EXT2_FEATURE_INCOMPAT_META_BG|
EXT4_FEATURE_INCOMPAT_FLEX_BG|
EXT4_FEATURE_INCOMPAT_MMP |
- EXT4_FEATURE_INCOMPAT_64BIT,
+ EXT4_FEATURE_INCOMPAT_64BIT |
+ EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM,
/* R/O compat */
EXT2_FEATURE_RO_COMPAT_LARGE_FILE|
EXT4_FEATURE_RO_COMPAT_HUGE_FILE|
@@ -2298,6 +2299,38 @@ int main (int argc, char *argv[])
exit(1);
}
+ /* Check the user's mkfs options for metadata checksumming */
+ if (!quiet &&
+ EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+ printf(_("Group descriptor checksums "
+ "are not enabled. This reduces the "
+ "coverage of metadata checksumming. "
+ "Pass -O uninit_bg to rectify.\n"));
+ if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
+ !EXT2_HAS_INCOMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM))
+ printf(_("Group descriptor checksums will not use "
+ "the faster metadata_checksum algorithm. "
+ "Pass -O bg_use_meta_csum to rectify.\n"));
+ if (!EXT2_HAS_INCOMPAT_FEATURE(fs->super,
+ EXT3_FEATURE_INCOMPAT_EXTENTS))
+ printf(_("Extents are not enabled. The file extent "
+ "tree can be checksummed, whereas block maps "
+ "cannot. Not enabling extents reduces the "
+ "coverage of metadata checksumming. "
+ "Pass -O extents to rectify.\n"));
+ if (!EXT2_HAS_INCOMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_INCOMPAT_64BIT))
+ printf(_("64-bit filesystem support is not "
+ "enabled. The larger fields afforded by "
+ "this feature enable full-strength "
+ "checksumming. Pass -O 64bit to rectify.\n"));
+ }
+
/* Can't undo discard ... */
if (!noaction && discard && (io_ptr != undo_io_manager)) {
retval = mke2fs_discard_device(fs);
--
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