bcachefs: bch2_alloc_write() should be writing for all devices

Alloc info isn't stored on a particular device, it makes no sense to
only be writing it out for rw members - this was causing fsck to not fix
alloc info errors, oops.

Also, make sure we write out alloc info in other repair paths.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/alloc_background.c

@@ -366,7 +366,7 @@ int bch2_alloc_write(struct bch_fs *c, unsigned flags)
 	unsigned i;
 	int ret = 0;
 
-	for_each_rw_member(ca, c, i) {
+	for_each_member_device(ca, c, i) {
 		bch2_dev_alloc_write(c, ca, flags);
 		if (ret) {
 			percpu_ref_put(&ca->io_ref);

fs/bcachefs/bcachefs.h

@@ -510,7 +510,7 @@ enum {
 
 	/* misc: */
 	BCH_FS_FIXED_GENS,
-	BCH_FS_ALLOC_WRITTEN,
+	BCH_FS_NEED_ALLOC_WRITE,
 	BCH_FS_REBUILD_REPLICAS,
 	BCH_FS_HOLD_BTREE_WRITES,
 };

fs/bcachefs/btree_gc.c

@@ -132,6 +132,7 @@ static int bch2_gc_mark_key(struct bch_fs *c, struct bkey_s_c k,
 					ptr->gen)) {
 				g2->_mark.gen	= g->_mark.gen		= ptr->gen;
 				g2->gen_valid	= g->gen_valid		= true;
+				set_bit(BCH_FS_NEED_ALLOC_WRITE, &c->flags);
 			}
 
 			if (mustfix_fsck_err_on(gen_cmp(ptr->gen, g->mark.gen) > 0, c,
@@ -145,6 +146,7 @@ static int bch2_gc_mark_key(struct bch_fs *c, struct bkey_s_c k,
 				g2->_mark.dirty_sectors		= 0;
 				g2->_mark.cached_sectors	= 0;
 				set_bit(BCH_FS_FIXED_GENS, &c->flags);
+				set_bit(BCH_FS_NEED_ALLOC_WRITE, &c->flags);
 			}
 		}
 	}
@@ -571,7 +573,7 @@ static int bch2_gc_done(struct bch_fs *c,
 			fsck_err(c, _msg ": got %llu, should be %llu"	\
 				, ##__VA_ARGS__, dst->_f, src->_f);	\
 		dst->_f = src->_f;					\
-		ret = 1;						\
+		set_bit(BCH_FS_NEED_ALLOC_WRITE, &c->flags);		\
 	}
 #define copy_stripe_field(_f, _msg, ...)				\
 	if (dst->_f != src->_f) {					\
@@ -582,7 +584,7 @@ static int bch2_gc_done(struct bch_fs *c,
 				dst->_f, src->_f);			\
 		dst->_f = src->_f;					\
 		dst->dirty = true;					\
-		ret = 1;						\
+		set_bit(BCH_FS_NEED_ALLOC_WRITE, &c->flags);		\
 	}
 #define copy_bucket_field(_f)						\
 	if (dst->b[b].mark._f != src->b[b].mark._f) {			\
@@ -593,7 +595,7 @@ static int bch2_gc_done(struct bch_fs *c,
 				bch2_data_types[dst->b[b].mark.data_type],\
 				dst->b[b].mark._f, src->b[b].mark._f);	\
 		dst->b[b]._mark._f = src->b[b].mark._f;			\
-		ret = 1;						\
+		set_bit(BCH_FS_NEED_ALLOC_WRITE, &c->flags);		\
 	}
 #define copy_dev_field(_f, _msg, ...)					\
 	copy_field(_f, "dev %u has wrong " _msg, i, ##__VA_ARGS__)

fs/bcachefs/recovery.c

@@ -938,7 +938,7 @@ int bch2_fs_recovery(struct bch_fs *c)
 	struct bch_sb_field_clean *clean = NULL;
 	struct jset *last_journal_entry = NULL;
 	u64 blacklist_seq, journal_seq;
-	bool write_sb = false, need_write_alloc = false;
+	bool write_sb = false;
 	int ret;
 
 	if (c->sb.clean)
@@ -1084,10 +1084,8 @@ int bch2_fs_recovery(struct bch_fs *c)
 		bch_info(c, "starting metadata mark and sweep");
 		err = "error in mark and sweep";
 		ret = bch2_gc(c, &c->journal_keys, true, true);
-		if (ret < 0)
-			goto err;
 		if (ret)
-			need_write_alloc = true;
+			goto err;
 		bch_verbose(c, "mark and sweep done");
 	}
 
@@ -1097,10 +1095,8 @@ int bch2_fs_recovery(struct bch_fs *c)
 		bch_info(c, "starting mark and sweep");
 		err = "error in mark and sweep";
 		ret = bch2_gc(c, &c->journal_keys, true, false);
-		if (ret < 0)
-			goto err;
 		if (ret)
-			need_write_alloc = true;
+			goto err;
 		bch_verbose(c, "mark and sweep done");
 	}
 
@@ -1124,7 +1120,8 @@ int bch2_fs_recovery(struct bch_fs *c)
 		goto err;
 	bch_verbose(c, "journal replay done");
 
-	if (need_write_alloc && !c->opts.nochanges) {
+	if (test_bit(BCH_FS_NEED_ALLOC_WRITE, &c->flags) &&
+	    !c->opts.nochanges) {
 		/*
 		 * note that even when filesystem was clean there might be work
 		 * to do here, if we ran gc (because of fsck) which recalculated
@@ -1139,8 +1136,6 @@ int bch2_fs_recovery(struct bch_fs *c)
 			goto err;
 		}
 		bch_verbose(c, "alloc write done");
-
-		set_bit(BCH_FS_ALLOC_WRITTEN, &c->flags);
 	}
 
 	if (!c->sb.clean) {