bcachefs: Fix gc updating stripes info

The primary stripes radix tree can be sparse, which was causing an
assertion to pop because the one use for gc isn't. Fix this by changing
the algorithm to copy between the two radix trees.

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

diff --git a/fs/bcachefs/btree_gc.c b/fs/bcachefs/btree_gc.c
index 790beac71e9b28df41da2e22cd15a25875d30175..f2310f7f89c5660ad24bd39582cf238422a1fff8 100644 (file)
--- a/fs/bcachefs/btree_gc.c
+++ b/fs/bcachefs/btree_gc.c
@@ -580,7 +580,7 @@ static int bch2_gc_done(struct bch_fs *c,
                if (verify)                                             \
                        fsck_err(c, "stripe %zu has wrong "_msg         \
                                ": got %u, should be %u",               \
-                               dst_iter.pos, ##__VA_ARGS__,            \
+                               iter.pos, ##__VA_ARGS__,                \
                                dst->_f, src->_f);                      \
                dst->_f = src->_f;                                      \
                dst->dirty = true;                                      \
@@ -603,13 +603,11 @@ static int bch2_gc_done(struct bch_fs *c,
        copy_field(_f, "fs has wrong " _msg, ##__VA_ARGS__)
 
        if (!metadata_only) {
-               struct genradix_iter dst_iter = genradix_iter_init(&c->stripes[0], 0);
-               struct genradix_iter src_iter = genradix_iter_init(&c->stripes[1], 0);
+               struct genradix_iter iter = genradix_iter_init(&c->stripes[1], 0);
                struct stripe *dst, *src;
 
-               while ((dst = genradix_iter_peek(&dst_iter, &c->stripes[0])) &&
-                      (src = genradix_iter_peek(&src_iter, &c->stripes[1]))) {
-                       BUG_ON(src_iter.pos != dst_iter.pos);
+               while ((src = genradix_iter_peek(&iter, &c->stripes[1]))) {
+                       dst = genradix_ptr_alloc(&c->stripes[0], iter.pos, GFP_KERNEL);
 
                        copy_stripe_field(alive,        "alive");
                        copy_stripe_field(sectors,      "sectors");
@@ -623,8 +621,7 @@ static int bch2_gc_done(struct bch_fs *c,
                                copy_stripe_field(block_sectors[i],
                                                  "block_sectors[%u]", i);
 
-                       genradix_iter_advance(&dst_iter, &c->stripes[0]);
-                       genradix_iter_advance(&src_iter, &c->stripes[1]);
+                       genradix_iter_advance(&iter, &c->stripes[1]);
                }
        }