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[PATCH v9 10/44] refs.c: change ref_transaction_update() to do error checking and return status

From
Ronnie Sahlberg <sahlberg@google.com>
Date
May 15, 2014, 23:15 UTC
Message-ID
<1400195741-22996-11-git-send-email-sahlberg@google.com>
In-Reply-To
<1400195741-22996-1-git-send-email-sahlberg@google.com>

Update ref_transaction_update() do some basic error checking and return non-zero on error. Update all callers to check ref_transaction_update() for error. There are currently no conditions in _update that will return error but there will be in the future. Add an err argument that will be updated on failure.

Also check for BUGs during update and die(BUG:...) if we are calling _update with have_old but the old_sha1 pointer is NULL.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 builtin/update-ref.c | 12 +++++++-----
 refs.c               | 18 ++++++++++++------
 refs.h               | 14 +++++++++-----
 3 files changed, 28 insertions(+), 16 deletions(-)
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 2bef2a0..9f328b2 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -16,6 +16,7 @@ static struct ref_transaction *transaction;
 
 static char line_termination = '\n';
 static int update_flags;
+static struct strbuf err = STRBUF_INIT;
 
 /*
  * Parse one whitespace- or NUL-terminated, possibly C-quoted argument
@@ -197,8 +198,9 @@ static const char *parse_cmd_update(struct strbuf *input, const char *next)
 	if (*next != line_termination)
 		die("update %s: extra input: %s", refname, next);
 
-	ref_transaction_update(transaction, refname, new_sha1, old_sha1,
-			       update_flags, have_old);
+	if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
+				   update_flags, have_old, &err))
+		die("update %s: failed: %s", refname, err.buf);
 
 	update_flags = 0;
 	free(refname);
@@ -286,8 +288,9 @@ static const char *parse_cmd_verify(struct strbuf *input, const char *next)
 	if (*next != line_termination)
 		die("verify %s: extra input: %s", refname, next);
 
-	ref_transaction_update(transaction, refname, new_sha1, old_sha1,
-			       update_flags, have_old);
+	if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
+				   update_flags, have_old, &err))
+		die("verify %s: %s", refname, err.buf);
 
 	update_flags = 0;
 	free(refname);
@@ -342,7 +345,6 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 	const char *refname, *oldval, *msg = NULL;
 	unsigned char sha1[20], oldsha1[20];
 	int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0, flags = 0;
-	struct strbuf err = STRBUF_INIT;
 	struct option options[] = {
 		OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
 		OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
diff --git a/refs.c b/refs.c
index 3eb73a3..3c9b981 100644
--- a/refs.c
+++ b/refs.c
@@ -3381,19 +3381,25 @@ static struct ref_update *add_update(struct ref_transaction *transaction,
 	return update;
 }
 
-void ref_transaction_update(struct ref_transaction *transaction,
-			    const char *refname,
-			    const unsigned char *new_sha1,
-			    const unsigned char *old_sha1,
-			    int flags, int have_old)
+int ref_transaction_update(struct ref_transaction *transaction,
+			   const char *refname,
+			   const unsigned char *new_sha1,
+			   const unsigned char *old_sha1,
+			   int flags, int have_old,
+			   struct strbuf *err)
 {
-	struct ref_update *update = add_update(transaction, refname);
+	struct ref_update *update;
+
+	if (have_old && !old_sha1)
+		die("BUG: have_old is true but old_sha1 is NULL");
 
+	update = add_update(transaction, refname);
 	hashcpy(update->new_sha1, new_sha1);
 	update->flags = flags;
 	update->have_old = have_old;
 	if (have_old)
 		hashcpy(update->old_sha1, old_sha1);
+	return 0;
 }
 
 void ref_transaction_create(struct ref_transaction *transaction,
diff --git a/refs.h b/refs.h
index 555ee59..11d07ee 100644
--- a/refs.h
+++ b/refs.h
@@ -242,12 +242,16 @@ void ref_transaction_rollback(struct ref_transaction *transaction);
  * be deleted.  If have_old is true, then old_sha1 holds the value
  * that the reference should have had before the update, or zeros if
  * it must not have existed beforehand.
+ * Function returns 0 on success and non-zero on failure. A failure to update
+ * means that the transaction as a whole has failed and will need to be
+ * rolled back. On failure the err buffer will be updated.
  */
-void ref_transaction_update(struct ref_transaction *transaction,
-			    const char *refname,
-			    const unsigned char *new_sha1,
-			    const unsigned char *old_sha1,
-			    int flags, int have_old);
+int ref_transaction_update(struct ref_transaction *transaction,
+			   const char *refname,
+			   const unsigned char *new_sha1,
+			   const unsigned char *old_sha1,
+			   int flags, int have_old,
+			   struct strbuf *err);
 
 /*
  * Add a reference creation to transaction.  new_sha1 is the value

-- 
2.0.0.rc3.477.gffe78a2
Previous: Ronnie SahlbergNext: Ronnie Sahlberg
Message 11 of 45 in “Use ref transactions for all ref updates”
  1. 00/44 Use ref transactions for all ref updatesRonnie Sahlberg, May 15, 2014
  2. 01/44 refs.c: constify the sha arguments for ref_transaction_create|delete|updateRonnie Sahlberg, May 15, 2014
  3. 02/44 refs.c: allow passing NULL to ref_transaction_freeRonnie Sahlberg, May 15, 2014
  4. 03/44 refs.c: add a strbuf argument to ref_transaction_commit for error loggingRonnie Sahlberg, May 15, 2014
  5. 04/44 refs.c: add an err argument to repack_without_refsRonnie Sahlberg, May 15, 2014
  6. 05/44 refs.c: make ref_update_reject_duplicates take a strbuf argument for errorsRonnie Sahlberg, May 15, 2014
  7. 06/44 refs.c: add an err argument to delete_ref_looseRonnie Sahlberg, May 15, 2014
  8. 07/44 refs.c: make update_ref_write update a strbuf on failureRonnie Sahlberg, May 15, 2014
  9. 08/44 update-ref.c: log transaction error from the update_refRonnie Sahlberg, May 15, 2014
  10. 09/44 refs.c: remove the onerr argument to ref_transaction_commitRonnie Sahlberg, May 15, 2014
  11. 10/44 refs.c: change ref_transaction_update() to do error checking and return statusRonnie Sahlberg, May 15, 2014
  12. 11/44 refs.c: change ref_transaction_create to do error checking and return statusRonnie Sahlberg, May 15, 2014
  13. 12/44 refs.c: ref_transaction_delete to check for error and return statusRonnie Sahlberg, May 15, 2014
  14. 13/44 tag.c: use ref transactions when doing updatesRonnie Sahlberg, May 15, 2014
  15. 14/44 replace.c: use the ref transaction functions for updatesRonnie Sahlberg, May 15, 2014
  16. 15/44 commit.c: use ref transactions for updatesRonnie Sahlberg, May 15, 2014
  17. 16/44 sequencer.c: use ref transactions for all ref updatesRonnie Sahlberg, May 15, 2014
  18. 17/44 fast-import.c: change update_branch to use ref transactionsRonnie Sahlberg, May 15, 2014
  19. 18/44 branch.c: use ref transaction for all ref updatesRonnie Sahlberg, May 15, 2014
  20. 19/44 refs.c: change update_ref to use a transactionRonnie Sahlberg, May 15, 2014
  21. 20/44 refs.c: free the transaction before returning when number of updates is 0Ronnie Sahlberg, May 15, 2014
  22. 21/44 refs.c: ref_transaction_commit should not free the transactionRonnie Sahlberg, May 15, 2014
  23. 22/44 fetch.c: clear errno before calling functions that might set itRonnie Sahlberg, May 15, 2014
  24. 23/44 fetch.c: change s_update_ref to use a ref transactionRonnie Sahlberg, May 15, 2014
  25. 24/44 fetch.c: use a single ref transaction for all ref updatesRonnie Sahlberg, May 15, 2014
  26. 25/44 receive-pack.c: use a reference transaction for updating the refsRonnie Sahlberg, May 15, 2014
  27. 26/44 fast-import.c: use a ref transaction when dumping tagsRonnie Sahlberg, May 15, 2014
  28. 27/44 walker.c: use ref transaction for ref updatesRonnie Sahlberg, May 15, 2014
  29. 28/44 refs.c: make write_ref_sha1 staticRonnie Sahlberg, May 15, 2014
  30. 29/44 refs.c: make lock_ref_sha1 staticRonnie Sahlberg, May 15, 2014
  31. 30/44 refs.c: add transaction.status and track OPEN/CLOSED/ERRORRonnie Sahlberg, May 15, 2014
  32. 31/44 refs.c: remove the update_ref_lock functionRonnie Sahlberg, May 15, 2014
  33. 32/44 refs.c: remove the update_ref_write functionRonnie Sahlberg, May 15, 2014
  34. 33/44 refs.c: remove lock_ref_sha1Ronnie Sahlberg, May 15, 2014
  35. 34/44 refs.c: make prune_ref use a transaction to delete the refRonnie Sahlberg, May 15, 2014
  36. 35/44 refs.c: make delete_ref use a transactionRonnie Sahlberg, May 15, 2014
  37. 36/44 refs.c: pass the ref log message to _create/delete/update instead of _commitRonnie Sahlberg, May 15, 2014
  38. 37/44 refs.c: pass NULL as *flags to read_ref_fullRonnie Sahlberg, May 15, 2014
  39. 38/44 refs.c: pack all refs before we start to rename a refRonnie Sahlberg, May 15, 2014
  40. 39/44 refs.c: move the check for valid refname to lock_ref_sha1_basicRonnie Sahlberg, May 15, 2014
  41. 40/44 refs.c: call lock_ref_sha1_basic directly from commitRonnie Sahlberg, May 15, 2014
  42. 41/44 refs.c: add a new flag for transaction delete for refs we know are packed onlyRonnie Sahlberg, May 15, 2014
  43. 42/44 refs.c: pass a skip list to name_conflict_fnRonnie Sahlberg, May 15, 2014
  44. 43/44 refs.c: make rename_ref use a transactionRonnie Sahlberg, May 15, 2014
  45. 44/44 refs.c: remove forward declaration of write_ref_sha1Ronnie Sahlberg, May 15, 2014

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