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Fixed gcksum mismatch in dirty/mutated traversal

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It's an error to check the gcksum if our traversal ends up
dirty/mutated, since it may be contain cksums from different filesystem
states.

We already avoid clearing the CKMETA flag if this happens, so no change
needed there. lfsr_fs_gc will continue to traverse until this flag is
cleared. (Though running a ckmeta scan to completion before any mutation
_would_ be more robust, hmm...)

Found by our test_traversal_mutation test.

Code changes were zero after tweaking lfsr_mtree_traverse to better
deduplicate ckmeta/ckdata eot conditions:

           code          stack          ctx
  before: 38572           2640          644
  after:  38572 (+0.0%)   2640 (+0.0%)  644 (+0.0%)
This commit is contained in:
Christopher Haster
2025-01-16 14:53:13 -06:00
parent adea19101d
commit 624eb1ad52
1 changed files with 5 additions and 3 deletions
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lfs.c
+5 -3
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@@ -9631,6 +9631,8 @@ eot:;
// compare gcksum with in-RAM gcksum
if ((lfsr_t_isckmeta(t->o.o.flags)
|| lfsr_t_isckdata(t->o.o.flags))
&& !lfsr_t_isdirty(t->o.o.flags)
&& !lfsr_t_ismutated(t->o.o.flags)
&& t->gcksum != lfs->gcksum) {
LFS_ERROR("Found gcksum mismatch, cksum %08"PRIx32" (!= %08"PRIx32")",
t->gcksum,
@@ -9640,7 +9642,8 @@ eot:;
// was ckmeta/ckdata successful? we only consider our filesystem
// checked if we weren't mutated
if (lfsr_t_isckmeta(t->o.o.flags)
if ((lfsr_t_isckmeta(t->o.o.flags)
|| lfsr_t_isckdata(t->o.o.flags))
&& !lfsr_t_ismtreeonly(t->o.o.flags)
&& !lfsr_t_isdirty(t->o.o.flags)
&& !lfsr_t_ismutated(t->o.o.flags)) {
@@ -9650,8 +9653,7 @@ eot:;
&& !lfsr_t_ismtreeonly(t->o.o.flags)
&& !lfsr_t_isdirty(t->o.o.flags)
&& !lfsr_t_ismutated(t->o.o.flags)) {
// note ckdata implies ckmeta
lfs->flags &= ~LFS_I_CKDATA & ~LFS_I_CKMETA;
lfs->flags &= ~LFS_I_CKDATA;
}
return LFS_ERR_NOENT;