WIP: bcachefs: new debug command

Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>

2 files changed, 126 insertions, 0 deletions

diff --git a/c_src/cmd_debug.c b/c_src/cmd_debug.c
new file mode 100644
index 00000000..9d5def1a
--- /dev/null
+++ b/c_src/cmd_debug.c
@@ -0,0 +1,115 @@
+#include <stdio.h>
+
+#include "libbcachefs/bkey_types.h"
+#include "libbcachefs/btree_update.h"
+#include "libbcachefs/printbuf.h"
+#include "libbcachefs/inode.h"
+
+#include "cmds.h"
+
+void write_field(void *base, u64 size, u64 offset, u64 value)
+{
+	u8 *field8;
+	u16 *field16;
+	u32 *field32;
+	u64 *field64;
+
+	switch (size) {
+	case 1:
+		field8 = (u8 *) base + offset;
+		*field8 = (u8) value;
+		break;
+	case 2:
+		field16 = (u16 *) ((u8 *) base + offset);
+		*field16 = (u16) value;
+		break;
+	case 4:
+		field32 = (u32 *) ((u8 *) base + offset);
+		*field32 = (u32) value;
+		break;
+	case 8:
+		field64 = (u64 *) ((u8 *) base + offset);
+		*field64 = value;
+		break;
+	default:
+		fprintf(stderr, "can't handle size %llu\n", size);
+	}
+}
+
+int cmd_dump_bkey(struct bch_fs *c, enum btree_id id, struct bpos pos)
+{
+	struct printbuf buf = PRINTBUF;
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter = { NULL };
+	int ret = 0;
+
+	bch2_trans_iter_init(trans, &iter, id, pos, BTREE_ITER_ALL_SNAPSHOTS);
+
+	struct bkey_s_c k = bch2_btree_iter_peek(&iter);
+	if (!bpos_eq(pos, k.k->p)) {
+		printf("no such key\n");
+		ret = 1;
+		goto out;
+	}
+
+	bch2_bkey_val_to_text(&buf, c, k);
+	printf("%s\n", buf.buf);
+
+out:
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+
+	return ret;
+}
+
+int cmd_update_bkey(struct bch_fs *c, struct bkey_update u, struct bpos pos)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter = { NULL };
+	int ret = 0;
+
+	set_bit(BCH_FS_no_invalid_checks, &c->flags);
+
+	if (!strcmp(u.bkey, "bch_inode_unpacked")) {
+		bch2_trans_iter_init(trans, &iter, BTREE_ID_inodes, pos,
+				     BTREE_ITER_ALL_SNAPSHOTS);
+
+		struct bkey_s_c k = bch2_btree_iter_peek(&iter);
+		if (bkey_err(k)) {
+			// TODO: is this proper error handling?
+			printf("error getting key: %s\n", bch2_err_str(PTR_ERR(k.k)));
+			ret = 1;
+			goto out;
+		}
+		struct bch_inode_unpacked inode;
+		// TODO: check error
+		bch2_inode_unpack(k, &inode);
+
+		write_field(&inode, u.size, u.offset, u.value);
+
+		ret = bch2_inode_write(trans, &iter, &inode) ?:
+			  bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_invalid_checks);
+		if (ret != 0) {
+			printf("ret = %s (%d)\n", bch2_err_str(ret), ret);
+		}
+	} else {
+		// TODO can this return an error?
+		struct bkey_i *k = bch2_bkey_get_mut(trans, &iter, u.id, pos,
+						     BTREE_ITER_ALL_SNAPSHOTS);
+		// TODO: check bkey type to confirm it matches specified type?
+		bch2_trans_unlock(trans);
+
+		write_field(&k->v, u.size, u.offset, u.value);
+
+		ret = bch2_btree_insert(c, u.id, k, NULL, BCH_TRANS_COMMIT_no_invalid_checks);
+		if (ret != 0) {
+			printf("ret = %s (%d)\n", bch2_err_str(ret), ret);
+		}
+	}
+
+out:
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+
+	return ret;
+}
diff --git a/c_src/cmds.h b/c_src/cmds.h
index 64267dc4..cb76f677 100644
--- a/c_src/cmds.h
+++ b/c_src/cmds.h
@@ -9,6 +9,14 @@
 
 #include "tools-util.h"
 
+struct bkey_update {
+	enum btree_id id;
+	const char *bkey;
+	u64 offset;
+	u64 size;
+	u64 value;
+};
+
 int cmd_format(int argc, char *argv[]);
 int cmd_show_super(int argc, char *argv[]);
 int cmd_reset_counters(int argc, char *argv[]);
@@ -54,6 +62,9 @@ int cmd_subvolume_snapshot(int argc, char *argv[]);
 
 int cmd_fusemount(int argc, char *argv[]);
 
+int cmd_dump_bkey(struct bch_fs *, enum btree_id, struct bpos);
+int cmd_update_bkey(struct bch_fs *, struct bkey_update, struct bpos);
+
 void bcachefs_usage(void);
 int device_cmds(int argc, char *argv[]);
 int fs_cmds(int argc, char *argv[]);