Move c_src dirs back to toplevel

[bcachefs-tools-debian] / libbcachefs / extent_update.c

diff --git a/libbcachefs/extent_update.c b/libbcachefs/extent_update.c
new file mode 100644 (file)
index 0000000..b9033bb
--- /dev/null
+++ b/libbcachefs/extent_update.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "bcachefs.h"
+#include "btree_update.h"
+#include "btree_update_interior.h"
+#include "buckets.h"
+#include "debug.h"
+#include "extents.h"
+#include "extent_update.h"
+
+/*
+ * This counts the number of iterators to the alloc & ec btrees we'll need
+ * inserting/removing this extent:
+ */
+static unsigned bch2_bkey_nr_alloc_ptrs(struct bkey_s_c k)
+{
+       struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+       const union bch_extent_entry *entry;
+       unsigned ret = 0, lru = 0;
+
+       bkey_extent_entry_for_each(ptrs, entry) {
+               switch (__extent_entry_type(entry)) {
+               case BCH_EXTENT_ENTRY_ptr:
+                       /* Might also be updating LRU btree */
+                       if (entry->ptr.cached)
+                               lru++;
+
+                       fallthrough;
+               case BCH_EXTENT_ENTRY_stripe_ptr:
+                       ret++;
+               }
+       }
+
+       /*
+        * Updating keys in the alloc btree may also update keys in the
+        * freespace or discard btrees:
+        */
+       return lru + ret * 2;
+}
+
+static int count_iters_for_insert(struct btree_trans *trans,
+                                 struct bkey_s_c k,
+                                 unsigned offset,
+                                 struct bpos *end,
+                                 unsigned *nr_iters,
+                                 unsigned max_iters)
+{
+       int ret = 0, ret2 = 0;
+
+       if (*nr_iters >= max_iters) {
+               *end = bpos_min(*end, k.k->p);
+               ret = 1;
+       }
+
+       switch (k.k->type) {
+       case KEY_TYPE_extent:
+       case KEY_TYPE_reflink_v:
+               *nr_iters += bch2_bkey_nr_alloc_ptrs(k);
+
+               if (*nr_iters >= max_iters) {
+                       *end = bpos_min(*end, k.k->p);
+                       ret = 1;
+               }
+
+               break;
+       case KEY_TYPE_reflink_p: {
+               struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
+               u64 idx = le64_to_cpu(p.v->idx);
+               unsigned sectors = bpos_min(*end, p.k->p).offset -
+                       bkey_start_offset(p.k);
+               struct btree_iter iter;
+               struct bkey_s_c r_k;
+
+               for_each_btree_key_norestart(trans, iter,
+                                  BTREE_ID_reflink, POS(0, idx + offset),
+                                  BTREE_ITER_SLOTS, r_k, ret2) {
+                       if (bkey_ge(bkey_start_pos(r_k.k), POS(0, idx + sectors)))
+                               break;
+
+                       /* extent_update_to_keys(), for the reflink_v update */
+                       *nr_iters += 1;
+
+                       *nr_iters += 1 + bch2_bkey_nr_alloc_ptrs(r_k);
+
+                       if (*nr_iters >= max_iters) {
+                               struct bpos pos = bkey_start_pos(k.k);
+                               pos.offset += min_t(u64, k.k->size,
+                                                   r_k.k->p.offset - idx);
+
+                               *end = bpos_min(*end, pos);
+                               ret = 1;
+                               break;
+                       }
+               }
+               bch2_trans_iter_exit(trans, &iter);
+
+               break;
+       }
+       }
+
+       return ret2 ?: ret;
+}
+
+#define EXTENT_ITERS_MAX       (BTREE_ITER_INITIAL / 3)
+
+int bch2_extent_atomic_end(struct btree_trans *trans,
+                          struct btree_iter *iter,
+                          struct bkey_i *insert,
+                          struct bpos *end)
+{
+       struct btree_iter copy;
+       struct bkey_s_c k;
+       unsigned nr_iters = 0;
+       int ret;
+
+       ret = bch2_btree_iter_traverse(iter);
+       if (ret)
+               return ret;
+
+       *end = insert->k.p;
+
+       /* extent_update_to_keys(): */
+       nr_iters += 1;
+
+       ret = count_iters_for_insert(trans, bkey_i_to_s_c(insert), 0, end,
+                                    &nr_iters, EXTENT_ITERS_MAX / 2);
+       if (ret < 0)
+               return ret;
+
+       bch2_trans_copy_iter(&copy, iter);
+
+       for_each_btree_key_upto_continue_norestart(copy, insert->k.p, 0, k, ret) {
+               unsigned offset = 0;
+
+               if (bkey_gt(bkey_start_pos(&insert->k), bkey_start_pos(k.k)))
+                       offset = bkey_start_offset(&insert->k) -
+                               bkey_start_offset(k.k);
+
+               /* extent_handle_overwrites(): */
+               switch (bch2_extent_overlap(&insert->k, k.k)) {
+               case BCH_EXTENT_OVERLAP_ALL:
+               case BCH_EXTENT_OVERLAP_FRONT:
+                       nr_iters += 1;
+                       break;
+               case BCH_EXTENT_OVERLAP_BACK:
+               case BCH_EXTENT_OVERLAP_MIDDLE:
+                       nr_iters += 2;
+                       break;
+               }
+
+               ret = count_iters_for_insert(trans, k, offset, end,
+                                       &nr_iters, EXTENT_ITERS_MAX);
+               if (ret)
+                       break;
+       }
+
+       bch2_trans_iter_exit(trans, &copy);
+       return ret < 0 ? ret : 0;
+}
+
+int bch2_extent_trim_atomic(struct btree_trans *trans,
+                           struct btree_iter *iter,
+                           struct bkey_i *k)
+{
+       struct bpos end;
+       int ret;
+
+       ret = bch2_extent_atomic_end(trans, iter, k, &end);
+       if (ret)
+               return ret;
+
+       bch2_cut_back(end, k);
+       return 0;
+}