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Replaced mleafweight with explicit 1 << mdir_bits

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The mleafweight naming is... not great...

Renaming mleaf_bits -> mdir_bits and replacing mleafweight with explicit
shifts of 1 << mdir_bits seems to get the job done without introducing a
new and potentially confusing name.

This was a lesson learned from recycle_bits. Sometimes more helpers just
makes code less, not more, readable.
This commit is contained in:
Christopher Haster
2024-05-24 01:30:51 -05:00
parent dd007245a7
commit 081a74cb23
3 changed files with 169 additions and 175 deletions
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lfs.c
+41 -47
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@@ -4944,21 +4944,17 @@ static int lfsr_btree_traverse(lfs_t *lfs, const lfsr_btree_t *btree,
/// metadata-id things ///
static inline lfsr_mid_t lfsr_mleafweight(const lfs_t *lfs) {
return 1 << lfs->mleaf_bits;
}
#define LFSR_MID(_lfs, _bid, _rid) \
(((_bid) & ~((1 << (_lfs)->mleaf_bits)-1)) + (_rid))
(((_bid) & ~((1 << (_lfs)->mdir_bits)-1)) + (_rid))
static inline lfsr_sbid_t lfsr_mid_bid(const lfs_t *lfs, lfsr_smid_t mid) {
return mid | ((1 << lfs->mleaf_bits) - 1);
return mid | ((1 << lfs->mdir_bits) - 1);
}
static inline lfsr_srid_t lfsr_mid_rid(const lfs_t *lfs, lfsr_smid_t mid) {
// bit of a strange mapping, but we want to preserve mid=-1 => rid=-1
return (mid >> (8*sizeof(lfsr_smid_t)-1))
| (mid & ((1 << lfs->mleaf_bits) - 1));
| (mid & ((1 << lfs->mdir_bits) - 1));
}
@@ -5438,7 +5434,7 @@ static int lfsr_data_readgrm(lfs_t *lfs, lfsr_data_t *data,
}
LFS_ASSERT((lfsr_mid_t)grm->mids[i] < lfs_max32(
lfsr_mtree_weight(&lfs->mtree),
lfsr_mleafweight(lfs)));
1 << lfs->mdir_bits));
}
return 0;
@@ -5783,7 +5779,7 @@ static int lfsr_mtree_lookup(lfs_t *lfs, const lfsr_mtree_t *mtree,
// looking up mroot?
if (lfsr_mtree_isnull(mtree)) {
LFS_ASSERT(mid >= 0);
LFS_ASSERT(mid < (lfsr_smid_t)lfsr_mleafweight(lfs));
LFS_ASSERT(mid < (1 << lfs->mdir_bits));
mdir_->mid = mid;
mdir_->rbyd = lfs->mroot.rbyd;
return 0;
@@ -5791,7 +5787,7 @@ static int lfsr_mtree_lookup(lfs_t *lfs, const lfsr_mtree_t *mtree,
// looking up direct mdir?
} else if (lfsr_mtree_ismptr(mtree)) {
LFS_ASSERT(mid >= 0);
LFS_ASSERT(mid < (lfsr_smid_t)lfsr_mleafweight(lfs));
LFS_ASSERT(mid < (1 << lfs->mdir_bits));
// fetch mdir
return lfsr_mdir_fetch(lfs, mdir_, mid, &mtree->u.mptr.mptr);
@@ -5837,14 +5833,14 @@ static int lfsr_mtree_seek(lfs_t *lfs, const lfsr_mtree_t *mtree,
// we don't know how many rids are in each mdir until we fetch
while (rid >= (lfsr_srid_t)mdir->rbyd.weight) {
// end of mtree?
if (bid+lfsr_mleafweight(lfs) >= lfsr_mtree_weight(mtree)) {
if (bid+(1 << lfs->mdir_bits) >= lfsr_mtree_weight(mtree)) {
// if we hit the end of the mtree, park the mdir so all future
// seeks return noent
mdir->mid = bid + lfsr_mleafweight(lfs);
mdir->mid = bid + (1 << lfs->mdir_bits);
return LFS_ERR_NOENT;
}
bid += lfsr_mleafweight(lfs);
bid += (1 << lfs->mdir_bits);
rid -= mdir->rbyd.weight;
int err = lfsr_mtree_lookup(lfs, mtree, bid, mdir);
if (err) {
@@ -6728,13 +6724,13 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
}
// adjust our sibling's mid after committing attrs
mdir_[1].mid += lfsr_mleafweight(lfs);
mdir_[1].mid += (1 << lfs->mdir_bits);
LFS_DEBUG("Splitting mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"} "
"-> 0x{%"PRIx32",%"PRIx32"}, "
"0x{%"PRIx32",%"PRIx32"}",
mdir->mid >> lfs->mleaf_bits,
mdir->mid >> lfs->mdir_bits,
mdir->rbyd.blocks[0], mdir->rbyd.blocks[1],
mdir_[0].rbyd.blocks[0], mdir_[0].rbyd.blocks[1],
mdir_[1].rbyd.blocks[0], mdir_[1].rbyd.blocks[1]);
@@ -6746,11 +6742,11 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
if (mdir_[0].rbyd.weight == 0 && mdir_[1].rbyd.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
mdir_[0].mid >> lfs->mleaf_bits,
mdir_[0].mid >> lfs->mdir_bits,
mdir_[0].rbyd.blocks[0], mdir_[0].rbyd.blocks[1]);
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
mdir_[1].mid >> lfs->mleaf_bits,
mdir_[1].mid >> lfs->mdir_bits,
mdir_[1].rbyd.blocks[0], mdir_[1].rbyd.blocks[1]);
goto drop;
@@ -6758,7 +6754,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
} else if (mdir_[0].rbyd.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
mdir_[0].mid >> lfs->mleaf_bits,
mdir_[0].mid >> lfs->mdir_bits,
mdir_[0].rbyd.blocks[0], mdir_[0].rbyd.blocks[1]);
mdir_[0].rbyd = mdir_[1].rbyd;
goto relocate;
@@ -6767,13 +6763,13 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
} else if (mdir_[1].rbyd.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
mdir_[1].mid >> lfs->mleaf_bits,
mdir_[1].mid >> lfs->mdir_bits,
mdir_[1].rbyd.blocks[0], mdir_[1].rbyd.blocks[1]);
goto relocate;
}
// no siblings reduced to zero, update our mtree
mdelta = +lfsr_mleafweight(lfs);
mdelta = +(1 << lfs->mdir_bits);
// lookup first name in sibling to use as the split name
//
@@ -6798,12 +6794,12 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
err = lfsr_btree_commit(lfs, &mtree_.u.btree,
0, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_MDIR, +lfsr_mleafweight(lfs),
LFSR_TAG_MDIR, +(1 << lfs->mdir_bits),
LFSR_DATA_MPTR_(
lfsr_mdir_mptr(&mdir_[0]),
&mdir_buf[0*LFSR_MPTR_DSIZE])),
LFSR_ATTR_CAT_(
LFSR_TAG_NAME, +lfsr_mleafweight(lfs),
LFSR_TAG_NAME, +(1 << lfs->mdir_bits),
&split_data, 1),
LFSR_ATTR(
LFSR_TAG_MDIR, 0,
@@ -6828,7 +6824,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
lfsr_mdir_mptr(&mdir_[0]),
&mdir_buf[0*LFSR_MPTR_DSIZE])),
LFSR_ATTR_CAT_(
LFSR_TAG_NAME, +lfsr_mleafweight(lfs),
LFSR_TAG_NAME, +(1 << lfs->mdir_bits),
&split_data, 1),
LFSR_ATTR(
LFSR_TAG_MDIR, 0,
@@ -6844,7 +6840,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
} else if (err == LFS_ERR_NOENT) {
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
mdir->mid >> lfs->mleaf_bits,
mdir->mid >> lfs->mdir_bits,
mdir->rbyd.blocks[0], mdir->rbyd.blocks[1]);
// consume gstate so we don't lose any info
@@ -6854,7 +6850,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
}
drop:;
mdelta = -lfsr_mleafweight(lfs);
mdelta = -(1 << lfs->mdir_bits);
// we should never drop a direct mdir, because we always have our
// root bookmark
@@ -6867,7 +6863,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
err = lfsr_btree_commit(lfs, &mtree_.u.btree,
lfsr_mid_bid(lfs, mdir->mid), LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_RM, -lfsr_mleafweight(lfs),
LFSR_TAG_RM, -(1 << lfs->mdir_bits),
LFSR_DATA_NULL())));
if (err) {
goto failed;
@@ -6878,7 +6874,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
&& lfsr_mdir_cmp(mdir, &lfs->mroot) != 0) {
LFS_DEBUG("Relocating mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"} -> 0x{%"PRIx32",%"PRIx32"}",
mdir->mid >> lfs->mleaf_bits,
mdir->mid >> lfs->mdir_bits,
mdir->rbyd.blocks[0], mdir->rbyd.blocks[1],
mdir_[0].rbyd.blocks[0], mdir_[0].rbyd.blocks[1]);
@@ -6887,7 +6883,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
if (lfsr_mtree_ismptr(&lfs->mtree)) {
mtree_ = LFSR_MTREE_MPTR(
*lfsr_mdir_mptr(&mdir_[0]),
lfsr_mleafweight(lfs));
1 << lfs->mdir_bits);
} else {
// mark as unerased in case of failure
@@ -6928,7 +6924,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
if (lfsr_mid_rid(lfs, lfs->grm.mids[j])
>= (lfsr_srid_t)mdir_[0].rbyd.weight) {
lfs->grm.mids[j]
+= lfsr_mleafweight(lfs) - mdir_[0].rbyd.weight;
+= (1 << lfs->mdir_bits) - mdir_[0].rbyd.weight;
}
} else if (lfs->grm.mids[j] > mdir->mid) {
lfs->grm.mids[j] += mdelta;
@@ -7108,7 +7104,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
if (mdelta > 0
&& lfsr_mid_rid(lfs, o->mdir.mid)
>= (lfsr_srid_t)mdir_[0].rbyd.weight) {
o->mdir.mid += lfsr_mleafweight(lfs) - mdir_[0].rbyd.weight;
o->mdir.mid += (1 << lfs->mdir_bits) - mdir_[0].rbyd.weight;
o->mdir.rbyd = mdir_[1].rbyd;
} else {
o->mdir.rbyd = mdir_[0].rbyd;
@@ -7123,7 +7119,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
if (mdelta > 0
&& lfsr_mid_rid(lfs, mdir->mid)
>= (lfsr_srid_t)mdir_[0].rbyd.weight) {
mdir->mid += lfsr_mleafweight(lfs) - mdir_[0].rbyd.weight;
mdir->mid += (1 << lfs->mdir_bits) - mdir_[0].rbyd.weight;
mdir->rbyd = mdir_[1].rbyd;
} else {
mdir->rbyd = mdir_[0].rbyd;
@@ -7231,7 +7227,7 @@ static int lfsr_mtree_namelookup(lfs_t *lfs, const lfsr_mtree_t *mtree,
return cmp;
}
LFS_ASSERT(tag == LFSR_TAG_MDIR);
LFS_ASSERT(weight == lfsr_mleafweight(lfs));
LFS_ASSERT(weight == (1U << lfs->mdir_bits));
// decode mdir
lfsr_mptr_t mptr;
@@ -7553,9 +7549,7 @@ static int lfsr_traversal_read(lfs_t *lfs, lfsr_traversal_t *t,
mptr.blocks[1]);
return LFS_ERR_CORRUPT;
}
if (t->u.mtortoise.step
// TODO why cast?
== ((lfs_block_t)1 << t->u.mtortoise.power)) {
if (t->u.mtortoise.step == (1U << t->u.mtortoise.power)) {
t->u.mtortoise.mptr = mptr;
t->u.mtortoise.step = 0;
t->u.mtortoise.power += 1;
@@ -8362,7 +8356,7 @@ static int lfsr_mountinited(lfs_t *lfs) {
if (lfsr_mtree_isnull(&lfs->mtree)) {
lfs->mtree = LFSR_MTREE_MPTR(
*lfsr_mdir_mptr(&tinfo.u.mdir),
lfsr_mleafweight(lfs));
(1 << lfs->mdir_bits));
}
}
@@ -8390,7 +8384,7 @@ static int lfsr_mountinited(lfs_t *lfs) {
LFS_DEBUG("Found orphaned file "
"%"PRId32".%"PRId32,
lfsr_mid_bid(lfs, tinfo.u.mdir.mid)
>> lfs->mleaf_bits,
>> lfs->mdir_bits,
rid);
lfs->hasorphans = true;
}
@@ -8434,13 +8428,13 @@ static int lfsr_mountinited(lfs_t *lfs) {
if (lfsr_grm_count(&lfs->grm) == 2) {
LFS_DEBUG("Found pending grm "
"%"PRId32".%"PRId32" %"PRId32".%"PRId32,
lfsr_mid_bid(lfs, lfs->grm.mids[0]) >> lfs->mleaf_bits,
lfsr_mid_bid(lfs, lfs->grm.mids[0]) >> lfs->mdir_bits,
lfsr_mid_rid(lfs, lfs->grm.mids[0]),
lfsr_mid_bid(lfs, lfs->grm.mids[1]) >> lfs->mleaf_bits,
lfsr_mid_bid(lfs, lfs->grm.mids[1]) >> lfs->mdir_bits,
lfsr_mid_rid(lfs, lfs->grm.mids[1]));
} else if (lfsr_grm_count(&lfs->grm) == 1) {
LFS_DEBUG("Found pending grm %"PRId32".%"PRId32,
lfsr_mid_bid(lfs, lfs->grm.mids[0]) >> lfs->mleaf_bits,
lfsr_mid_bid(lfs, lfs->grm.mids[0]) >> lfs->mdir_bits,
lfsr_mid_rid(lfs, lfs->grm.mids[0]));
}
}
@@ -8540,8 +8534,8 @@ int lfsr_mount(lfs_t *lfs, const struct lfs_config *cfg) {
lfs->mroot.rbyd.blocks[0],
lfs->mroot.rbyd.blocks[1],
lfsr_rbyd_trunk(&lfs->mroot.rbyd),
lfsr_mtree_weight(&lfs->mtree) / lfsr_mleafweight(lfs),
lfsr_mleafweight(lfs));
lfsr_mtree_weight(&lfs->mtree) >> lfs->mdir_bits,
1 << lfs->mdir_bits);
return 0;
}
@@ -8735,7 +8729,7 @@ static int lfsr_fs_fixgrm(lfs_t *lfs) {
lfsr_mdir_t mdir;
LFS_ASSERT(lfs->grm.mids[0] < lfs_smax32(
lfsr_mtree_weight(&lfs->mtree),
lfsr_mleafweight(lfs)));
1 << lfs->mdir_bits));
int err = lfsr_mtree_lookup(lfs, &lfs->mtree, lfs->grm.mids[0],
&mdir);
if (err) {
@@ -8830,13 +8824,13 @@ static int lfsr_fs_preparemutation(lfs_t *lfs) {
if (lfsr_grm_count(&lfs->grm) == 2) {
LFS_DEBUG("Fixing grm "
"%"PRId32".%"PRId32" %"PRId32".%"PRId32"...",
lfsr_mid_bid(lfs, lfs->grm.mids[0]) >> lfs->mleaf_bits,
lfsr_mid_bid(lfs, lfs->grm.mids[0]) >> lfs->mdir_bits,
lfsr_mid_rid(lfs, lfs->grm.mids[0]),
lfsr_mid_bid(lfs, lfs->grm.mids[1]) >> lfs->mleaf_bits,
lfsr_mid_bid(lfs, lfs->grm.mids[1]) >> lfs->mdir_bits,
lfsr_mid_rid(lfs, lfs->grm.mids[1]));
} else {
LFS_DEBUG("Fixing grm %"PRId32".%"PRId32,
lfsr_mid_bid(lfs, lfs->grm.mids[0]) >> lfs->mleaf_bits,
lfsr_mid_bid(lfs, lfs->grm.mids[0]) >> lfs->mdir_bits,
lfsr_mid_rid(lfs, lfs->grm.mids[0]));
}
inconsistent = true;
@@ -15452,7 +15446,7 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
// metadata entries per block. But we intentionally don't leverage this
// to maintain compatibility with a theoretical perfect implementation.
//
lfs->mleaf_bits = lfs_nlog2(lfs->cfg->block_size/8);
lfs->mdir_bits = lfs_nlog2(lfs->cfg->block_size/8);
// zero linked-list of opened mdirs
lfs->opened = NULL;