git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH v3 06/19] delete_refs(): bail early if the packed-refs file cannot be rewritten

From
Michael Haggerty <mhagger@alum.mit.edu>
Date
Jun 22, 2015, 14:02 UTC
Message-ID
<28505bdd95dc4da84bef1afc709a51d99718a5ad.1434980615.git.mhagger@alum.mit.edu>
In-Reply-To
<cover.1434980615.git.mhagger@alum.mit.edu>

If we fail to delete the doomed references from the packed-refs file, then it is unsafe to delete their loose references, because doing so might expose a value from the packed-refs file that is obsolete and perhaps even points at an object that has been garbage collected.

So if repack_without_refs() fails, emit a more explicit error message and bail.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 refs.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)
diff --git a/refs.c b/refs.c
index 5386077..19afc4d 100644
--- a/refs.c
+++ b/refs.c
@@ -2823,9 +2823,26 @@ int delete_refs(struct string_list *refnames)
 	struct strbuf err = STRBUF_INIT;
 	int i, result = 0;
 
-	if (repack_without_refs(refnames, &err))
-		result |= error("%s", err.buf);
-	strbuf_release(&err);
+	if (!refnames->nr)
+		return 0;
+
+	result = repack_without_refs(refnames, &err);
+	if (result) {
+		/*
+		 * If we failed to rewrite the packed-refs file, then
+		 * it is unsafe to try to remove loose refs, because
+		 * doing so might expose an obsolete packed value for
+		 * a reference that might even point at an object that
+		 * has been garbage collected.
+		 */
+		if (refnames->nr == 1)
+			error(_("could not delete reference %s: %s"),
+			      refnames->items[0].string, err.buf);
+		else
+			error(_("could not delete references: %s"), err.buf);
+
+		goto out;
+	}
 
 	for (i = 0; i < refnames->nr; i++) {
 		const char *refname = refnames->items[i].string;
@@ -2834,6 +2851,8 @@ int delete_refs(struct string_list *refnames)
 			result |= error(_("could not remove reference %s"), refname);
 	}
 
+out:
+	strbuf_release(&err);
 	return result;
 }
 

-- 
2.1.4
Previous: Michael HaggertyNext: Michael Haggerty
Message 7 of 24 in “Improve "refs" encapsulation and speed up deletes”
  1. 00/19 Improve "refs" encapsulation and speed up deletesMichael Haggerty, Jun 22, 2015
  2. 01/19 delete_ref(): move declaration to refs.hMichael Haggerty, Jun 22, 2015
  3. 02/19 remove_branches(): remove temporaryMichael Haggerty, Jun 22, 2015
  4. 03/19 delete_ref(): handle special case more explicitlyMichael Haggerty, Jun 22, 2015
  5. 04/19 delete_refs(): new function for the refs APIMichael Haggerty, Jun 22, 2015
  6. 05/19 delete_refs(): make error message more genericMichael Haggerty, Jun 22, 2015
  7. 06/19 delete_refs(): bail early if the packed-refs file cannot be rewrittenMichael Haggerty, Jun 22, 2015
  8. 07/19 prune_remote(): use delete_refs()Michael Haggerty, Jun 22, 2015
  9. 08/19 prune_refs(): use delete_refs()Michael Haggerty, Jun 22, 2015
  10. 09/19 repack_without_refs(): make function privateMichael Haggerty, Jun 22, 2015
  11. 10/19 initial_ref_transaction_commit(): function for initial ref creationMichael Haggerty, Jun 22, 2015
  12. 11/19 refs: remove some functions from the module's public interfaceMichael Haggerty, Jun 22, 2015
  13. 12/19 initial_ref_transaction_commit(): check for duplicate refsMichael Haggerty, Jun 22, 2015
  14. Junio C HamanoJun 22, 2015
  15. Michael HaggertyJun 23, 2015
  16. Junio C HamanoJun 23, 2015
  17. 13/19 initial_ref_transaction_commit(): check for ref D/F conflictsMichael Haggerty, Jun 22, 2015
  18. 14/19 refs: move the remaining ref module declarations to refs.hMichael Haggerty, Jun 22, 2015
  19. 15/19 refs.h: add some parameter names to function declarationsMichael Haggerty, Jun 22, 2015
  20. 16/19 check_branch_commit(): make first parameter constMichael Haggerty, Jun 22, 2015
  21. 17/19 update_ref(): don't read old reference value before deleteMichael Haggerty, Jun 22, 2015
  22. 18/19 cmd_update_ref(): make logic more straightforwardMichael Haggerty, Jun 22, 2015
  23. 19/19 delete_ref(): use the usual convention for old_sha1Michael Haggerty, Jun 22, 2015
  24. Junio C HamanoJun 22, 2015

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.