bcachefs: Drop journal entry compaction

Previously, we dropped empty journal entries and coalesced entries that
could be - but it's not worth the overhead; we very rarely leave unused
journal entries after getting a journal reservation.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/journal_io.c b/fs/bcachefs/journal_io.c
index 4d8e10c901a8ff3cd632d5ddb6e3d9bcb2d9f015..6db821c8655107bcd233edb60e19d2c7d1bbbafb 100644 (file)
--- a/fs/bcachefs/journal_io.c
+++ b/fs/bcachefs/journal_io.c
@@ -1725,7 +1725,7 @@ static CLOSURE_CALLBACK(do_journal_write)
 static int bch2_journal_write_prep(struct journal *j, struct journal_buf *w)
 {
        struct bch_fs *c = container_of(j, struct bch_fs, journal);
-       struct jset_entry *start, *end, *i, *next, *prev = NULL;
+       struct jset_entry *start, *end, *i;
        struct jset *jset = w->data;
        struct journal_keys_to_wb wb = { NULL };
        unsigned sectors, bytes, u64s;
@@ -1742,7 +1742,7 @@ static int bch2_journal_write_prep(struct journal *j, struct journal_buf *w)
         * If we wanted to be really fancy here, we could sort all the keys in
         * the jset and drop keys that were overwritten - probably not worth it:
         */
-       vstruct_for_each_safe(jset, i, next) {
+       vstruct_for_each(jset, i) {
                unsigned u64s = le16_to_cpu(i->u64s);
 
                /* Empty entry: */
@@ -1782,34 +1782,12 @@ static int bch2_journal_write_prep(struct journal *j, struct journal_buf *w)
                        i->type = BCH_JSET_ENTRY_btree_keys;
                        break;
                }
-
-               /* Can we merge with previous entry? */
-               if (prev &&
-                   i->btree_id == prev->btree_id &&
-                   i->level    == prev->level &&
-                   i->type     == prev->type &&
-                   i->type     == BCH_JSET_ENTRY_btree_keys &&
-                   le16_to_cpu(prev->u64s) + u64s <= U16_MAX) {
-                       memmove_u64s_down(vstruct_next(prev),
-                                         i->_data,
-                                         u64s);
-                       le16_add_cpu(&prev->u64s, u64s);
-                       continue;
-               }
-
-               /* Couldn't merge, move i into new position (after prev): */
-               prev = prev ? vstruct_next(prev) : jset->start;
-               if (i != prev)
-                       memmove_u64s_down(prev, i, jset_u64s(u64s));
        }
 
        if (wb.wb)
                bch2_journal_keys_to_write_buffer_end(c, &wb);
        w->need_flush_to_write_buffer = false;
 
-       prev = prev ? vstruct_next(prev) : jset->start;
-       jset->u64s = cpu_to_le32((u64 *) prev - jset->_data);
-
        start = end = vstruct_last(jset);
 
        end     = bch2_btree_roots_to_journal_entries(c, end, btree_roots_have);