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Fixed two issues related to converting to bshrubs

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1. We used a temporary bshrub outside of the tracked ftree to commit
   without clobbering the ftree. This breaks the invariant that all
   bshrubs are tracked during mdir commit.

   By luck, the bshrubs were still working. They normally don't get
   staged properly without this invariant, but:

   1. These are always new bshrubs, so no state for mdir compact to be
      aware of.

   2. These are always immediately SHRUBCOMMITed, so they happen to get
      staged.

   But we can avoid breaking this invariant by encoding the commit
   first. We may clobber the ftree, but this is what our on-stack ftree
   copies are for.

2. We weren't including becksums when converting bptrs to bshrubs.

   Maybe we shouldn't care about this, since we don't create direct
   bptrs in normal operation. But I guess we'll be compat friendly for
   now...
This commit is contained in:
Christopher Haster
2024-01-01 14:18:38 -06:00
parent 8f2a6a3095
commit 8c1fe11c4d
1 changed files with 35 additions and 14 deletions
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lfs.c
+35 -14
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@@ -9651,28 +9651,49 @@ static int lfsr_ftree_carve(lfs_t *lfs, lfsr_ftree_t *ftree,
// always convert to bshrub/btree when this function is called
if (!lfsr_ftree_isbshruborbtree(ftree)) {
lfsr_bshrub_t bshrub;
int err = lfsr_bshrub_alloc(lfs, &ftree->mdir, &bshrub);
// TODO adopt this pattern for other scratch attrs
//
// try to merge commits where possible
lfsr_attr_t attrs_[2];
lfs_size_t attr_count_ = 0;
uint8_t buf[LFSR_BPTR_DSIZE+LFSR_ECKSUM_DSIZE];
lfs_size_t buf_size = 0;
// these also check if ftree is non-zero
if (lfsr_ftree_isbsprout(ftree)) {
attrs_[attr_count_++] = LFSR_ATTR(0,
DATA, +lfsr_ftree_size(ftree),
DATA(ftree->u.bsprout.data));
} else if (lfsr_ftree_isbleaf(ftree)) {
attrs_[attr_count_++] = LFSR_ATTR(0,
BLOCK, +lfsr_ftree_size(ftree),
FROMBPTR(&ftree->u.bptr, &buf[buf_size]));
buf_size += LFSR_BPTR_DSIZE;
// append becksum?
if (ftree->u.bleaf.becksum.size != -1) {
attrs_[attr_count_++] = LFSR_ATTR(lfsr_ftree_size(ftree)-1,
BECKSUM, 0,
FROMECKSUM(&ftree->u.bleaf.becksum, &buf[buf_size]));
buf_size += LFSR_ECKSUM_DSIZE;
}
}
int err = lfsr_bshrub_alloc(lfs, &ftree->mdir, &ftree->u.bshrub);
if (err) {
return err;
}
if (lfsr_ftree_size(ftree) > 0) {
uint8_t bptr_buf[LFSR_BPTR_DSIZE];
err = lfsr_bshrub_commit(lfs, &ftree->mdir, &bshrub, LFSR_ATTRS(
(lfsr_ftree_isbsprout(ftree))
? LFSR_ATTR(0,
DATA, +lfsr_ftree_size(ftree),
DATA(ftree->u.bsprout.data))
: LFSR_ATTR(0,
BLOCK, +lfsr_ftree_size(ftree),
FROMBPTR(&ftree->u.bptr, bptr_buf))));
if (attr_count_ > 0) {
LFS_ASSERT(attr_count_ <= sizeof(attrs_)/sizeof(lfsr_attr_t));
LFS_ASSERT(buf_size <= sizeof(buf));
err = lfsr_bshrub_commit(lfs, &ftree->mdir, &ftree->u.bshrub,
attrs_, attr_count_);
if (err) {
return err;
}
}
ftree->u.bshrub = bshrub;
}
// TODO adopt this pattern for other scratch attrs