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mirror of https://github.com/Zygo/bees.git synced 2025-06-16 09:36:17 +02:00

context: drop long-dead ExtentWalker code

At some point BtrfsExtentWalker will be fully deprecated and removed from
bees.  Might as well start with code that hasn't been built in 6 years.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>
This commit is contained in:
Zygo Blaxell
2022-11-19 17:17:36 -05:00
parent 31b2aa3c0d
commit 83a2b010e6

View File

@ -607,57 +607,6 @@ BeesContext::scan_one_extent(const BeesFileRange &bfr, const Extent &e)
BEESCOUNT(scan_zero_compressed); BEESCOUNT(scan_zero_compressed);
} }
// Turning this off because it's a waste of time on small extents
// and it's incorrect for large extents.
#if 0
// If the extent contains obscured blocks, and we can find no
// other refs to the extent that reveal those blocks, nuke the incoming extent.
// Don't rewrite extents that are bigger than the maximum FILE_EXTENT_SAME size
// because we can't make extents that large with dedupe.
// Don't rewrite small extents because it is a waste of time without being
// able to combine them into bigger extents.
if (!rewrite_extent && (e.flags() & Extent::OBSCURED) && (e.physical_len() > BLOCK_SIZE_MAX_COMPRESSED_EXTENT) && (e.physical_len() < BLOCK_SIZE_MAX_EXTENT_SAME)) {
BEESCOUNT(scan_obscured);
BEESNOTE("obscured extent " << e);
// We have to map all the source blocks to see if any of them
// (or all of them aggregated) provide a path through the FS to the blocks
BeesResolver br(m_ctx, BeesAddress(e, e.begin()));
BeesBlockData ref_bbd(bfr.fd(), bfr.begin(), min(BLOCK_SIZE_SUMS, bfr.size()));
// BEESLOG("ref_bbd " << ref_bbd);
auto bfr_set = br.find_all_matches(ref_bbd);
bool non_obscured_extent_found = false;
set<off_t> blocks_to_find;
for (off_t j = 0; j < e.physical_len(); j += BLOCK_SIZE_CLONE) {
blocks_to_find.insert(j);
}
// Don't bother if saving less than 1%
auto maximum_hidden_count = blocks_to_find.size() / 100;
for (auto i : bfr_set) {
BtrfsExtentWalker ref_ew(bfr.fd(), bfr.begin(), m_ctx->root_fd());
Extent ref_e = ref_ew.current();
// BEESLOG("\tref_e " << ref_e);
THROW_CHECK2(out_of_range, ref_e, e, ref_e.offset() + ref_e.logical_len() <= e.physical_len());
for (off_t j = ref_e.offset(); j < ref_e.offset() + ref_e.logical_len(); j += BLOCK_SIZE_CLONE) {
blocks_to_find.erase(j);
}
if (blocks_to_find.size() <= maximum_hidden_count) {
BEESCOUNT(scan_obscured_miss);
BEESLOG("Found references to all but " << blocks_to_find.size() << " blocks");
non_obscured_extent_found = true;
break;
} else {
BEESCOUNT(scan_obscured_hit);
// BEESLOG("blocks_to_find: " << blocks_to_find.size() << " from " << *blocks_to_find.begin() << ".." << *blocks_to_find.rbegin());
}
}
if (!non_obscured_extent_found) {
// BEESLOG("No non-obscured extents found");
rewrite_extent = true;
BEESCOUNT(scan_obscured_rewrite);
}
}
#endif
// If we deduped any blocks then we must rewrite the remainder of the extent // If we deduped any blocks then we must rewrite the remainder of the extent
if (!noinsert_set.empty()) { if (!noinsert_set.empty()) {
rewrite_extent = true; rewrite_extent = true;