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Rearranged lfsr_mdir_commit prologue/epilogue a bit

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Mainly to make our bshrub-in-mdir assert stricter (we need to update
mdirs first to assert bshrubs end up in the right mdirs), but also to
make lfsr_mdir_commit epilogue mirror the prologue a bit better. In this
function especially, readability is important.

And hey, code changes no worse for the wear:

           code          stack          ctx
  before: 36424           2608          640
  after:  36432 (+0.0%)   2608 (+0.0%)  640 (+0.0%)
This commit is contained in:
Christopher Haster
2025-02-02 18:24:43 -06:00
parent 77a9ce3418
commit 6d5be2922a
1 changed files with 35 additions and 29 deletions
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lfs.c
+35 -29
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@@ -8135,6 +8135,18 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
// xor our old cksum
lfs->gcksum ^= mdir->rbyd.cksum;
// stage any bshrubs
for (lfsr_omdir_t *o = lfs->omdirs; o; o = o->next) {
if (lfsr_o_isbshrub(o->flags)) {
// a bshrub outside of its mdir means something has gone
// horribly wrong
LFS_ASSERT(!lfsr_bshrub_isbshrub(&((lfsr_obshrub_t*)o)->bshrub)
|| ((lfsr_obshrub_t*)o)->bshrub.u.bshrub.blocks[0]
== o->mdir.rbyd.blocks[0]);
((lfsr_obshrub_t*)o)->bshrub_ = ((lfsr_obshrub_t*)o)->bshrub;
}
}
// create a copy
lfsr_mdir_t mdir_[2];
mdir_[0] = *mdir;
@@ -8148,16 +8160,6 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
if (lfsr_mdir_cmp(&o->mdir, mdir) == 0) {
o->mdir.rbyd.eoff = -1;
}
// stage any bshrubs
if (lfsr_o_isbshrub(o->flags)) {
// a bshrub outside of its mdir means something has gone
// horribly wrong
LFS_ASSERT(!lfsr_bshrub_isbshrub(&((lfsr_obshrub_t*)o)->bshrub)
|| ((lfsr_obshrub_t*)o)->bshrub.u.bshrub.blocks[0]
== o->mdir.rbyd.blocks[0]);
((lfsr_obshrub_t*)o)->bshrub_ = ((lfsr_obshrub_t*)o)->bshrub;
}
}
// attempt to commit/compact the mdir normally
@@ -8605,14 +8607,6 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
// success? update in-device state, we must not error at this point! //
///////////////////////////////////////////////////////////////////////
// we may have touched any number of mdirs, so assume uncompacted
// until lfsr_gc can prove otherwise
lfs->flags |= LFS_I_COMPACT;
// update any gstate changes
lfsr_fs_commitgdelta(lfs);
lfsr_fs_flushgdelta(lfs);
// play out any rats that affect internal state
mid_ = mdir->mid;
for (lfs_size_t i = 0; i < rat_count; i++) {
@@ -8637,16 +8631,6 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
mid_ = lfsr_rat_nextrid(rats[i], mid_);
}
// update any staged bshrubs
for (lfsr_omdir_t *o = lfs->omdirs; o; o = o->next) {
if (lfsr_o_isbshrub(o->flags)) {
((lfsr_obshrub_t*)o)->bshrub = ((lfsr_obshrub_t*)o)->bshrub_;
}
}
// mark all traversals as dirty
lfsr_fs_mkdirty(lfs);
// if mroot/mtree changed, clobber any mroot/mtree traversals
if (lfsr_mdir_cmp(&mroot_, &lfs->mroot) != 0
|| lfsr_btree_cmp(&mtree_, &lfs->mtree) != 0) {
@@ -8700,6 +8684,28 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
lfsr_mdir_sync(&lfs->mroot, &mroot_);
lfs->mtree = mtree_;
// update any staged bshrubs
for (lfsr_omdir_t *o = lfs->omdirs; o; o = o->next) {
if (lfsr_o_isbshrub(o->flags)) {
// a bshrub outside of its mdir means something has gone
// horribly wrong
LFS_ASSERT(!lfsr_bshrub_isbshrub(&((lfsr_obshrub_t*)o)->bshrub_)
|| ((lfsr_obshrub_t*)o)->bshrub_.u.bshrub.blocks[0]
== o->mdir.rbyd.blocks[0]);
((lfsr_obshrub_t*)o)->bshrub = ((lfsr_obshrub_t*)o)->bshrub_;
}
}
// update any gstate changes
lfsr_fs_commitgdelta(lfs);
// mark all traversals as dirty
lfsr_fs_mkdirty(lfs);
// we may have touched any number of mdirs, so assume uncompacted
// until lfsr_fs_gc can prove otherwise
lfs->flags |= LFS_I_COMPACT;
#ifdef LFS_DEBUGMDIRCOMMITS
LFS_DEBUG("Committed mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}.%"PRIx32" w%"PRId32", "
@@ -12897,7 +12903,7 @@ static int lfs_init(lfs_t *lfs, uint32_t flags,
// default to an empty lookahead
| LFS_I_LOOKAHEAD
// default to assuming we need compaction somewhere, worst case
// this just makes lfsr_gc read more than is strictly needed
// this just makes lfsr_fs_gc read more than is strictly needed
| LFS_I_COMPACT
// default to needing a ckmeta/ckdata scan
| LFS_I_CKMETA