[v4,09/13] tools/xenstore: add TDB access trace support

Commit Message

Jürgen Groß April 5, 2023, 7:03 a.m. UTC

Add a new trace switch "tdb" and the related trace calls.

The "tdb" switch is off per default.

Signed-off-by: Juergen Gross <[e-mail]>
Reviewed-by: Julien Grall <[e-mail]>
---
 tools/xenstore/xenstored_core.c        | 8 +++++++-
 tools/xenstore/xenstored_core.h        | 7 +++++++
 tools/xenstore/xenstored_transaction.c | 7 ++++++-
 3 files changed, 20 insertions(+), 2 deletions(-)

Patch

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index bd816ce709..2d481fcad9 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -589,6 +589,8 @@  static void get_acc_data(TDB_DATA *key, struct node_account_data *acc)
 		if (old_data.dptr == NULL) {
 			acc->memory = 0;
 		} else {
+			trace_tdb("read %s size %zu\n", key->dptr,
+				  old_data.dsize + key->dsize);
 			hdr = (void *)old_data.dptr;
 			acc->memory = old_data.dsize;
 			acc->domid = hdr->perms[0].id;
@@ -655,6 +657,7 @@  int do_tdb_write(struct connection *conn, TDB_DATA *key, TDB_DATA *data,
 		errno = EIO;
 		return errno;
 	}
+	trace_tdb("store %s size %zu\n", key->dptr, data->dsize + key->dsize);
 
 	if (acc) {
 		/* Don't use new_domid, as it might be a transaction node. */
@@ -682,6 +685,7 @@  int do_tdb_delete(struct connection *conn, TDB_DATA *key,
 		errno = EIO;
 		return errno;
 	}
+	trace_tdb("delete %s\n", key->dptr);
 
 	if (acc->memory) {
 		domid = get_acc_domid(conn, key, acc->domid);
@@ -731,6 +735,8 @@  struct node *read_node(struct connection *conn, const void *ctx,
 		goto error;
 	}
 
+	trace_tdb("read %s size %zu\n", key.dptr, data.dsize + key.dsize);
+
 	node->parent = NULL;
 	talloc_steal(node, data.dptr);
 
@@ -2746,7 +2752,7 @@  static void set_quota(const char *arg, bool soft)
 
 /* Sorted by bit values of TRACE_* flags. Flag is (1u << index). */
 const char *const trace_switches[] = {
-	"obj", "io", "wrl", "acc",
+	"obj", "io", "wrl", "acc", "tdb",
 	NULL
 };
 
diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
index 3e0734a6c6..5a11dc1231 100644
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -303,9 +303,16 @@  extern unsigned int trace_flags;
 #define TRACE_IO	0x00000002
 #define TRACE_WRL	0x00000004
 #define TRACE_ACC	0x00000008
+#define TRACE_TDB	0x00000010
 extern const char *const trace_switches[];
 int set_trace_switch(const char *arg);
 
+#define trace_tdb(...)				\
+do {						\
+	if (trace_flags & TRACE_TDB)		\
+		trace("tdb: " __VA_ARGS__);	\
+} while (0)
+
 extern TDB_CONTEXT *tdb_ctx;
 extern int dom0_domid;
 extern int dom0_event;
diff --git a/tools/xenstore/xenstored_transaction.c b/tools/xenstore/xenstored_transaction.c
index 2b15506953..11c8bcec84 100644
--- a/tools/xenstore/xenstored_transaction.c
+++ b/tools/xenstore/xenstored_transaction.c
@@ -374,8 +374,11 @@  static int finalize_transaction(struct connection *conn,
 				if (tdb_error(tdb_ctx) != TDB_ERR_NOEXIST)
 					return EIO;
 				gen = NO_GENERATION;
-			} else
+			} else {
+				trace_tdb("read %s size %zu\n", key.dptr,
+					  key.dsize + data.dsize);
 				gen = hdr->generation;
+			}
 			talloc_free(data.dptr);
 			if (i->generation != gen)
 				return EAGAIN;
@@ -399,6 +402,8 @@  static int finalize_transaction(struct connection *conn,
 			set_tdb_key(i->trans_name, &ta_key);
 			data = tdb_fetch(tdb_ctx, ta_key);
 			if (data.dptr) {
+				trace_tdb("read %s size %zu\n", ta_key.dptr,
+					  ta_key.dsize + data.dsize);
 				hdr = (void *)data.dptr;
 				hdr->generation = ++generation;
 				*is_corrupt |= do_tdb_write(conn, &key, &data,