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[PATCH v17 10/48] refs.c: verify_lock should set errno to something meaningful

From
Ronnie Sahlberg <sahlberg@google.com>
Date
Jun 16, 2014, 18:03 UTC
Message-ID
<1402941859-29354-11-git-send-email-sahlberg@google.com>
In-Reply-To
<1402941859-29354-1-git-send-email-sahlberg@google.com>

Making errno when returning from verify_lock() meaningful, which should almost but not completely fix

 * a bug in "git fetch"'s s_update_ref, which trusts the result of an
   errno == ENOTDIR check to detect D/F conflicts

ENOTDIR makes sense as a sign that a file was in the way of a directory we wanted to create. Should "git fetch" also look for ENOTEMPTY or EEXIST to catch cases where a directory was in the way of a file to be created?

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 refs.c | 4 ++++
 refs.h | 6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/refs.c b/refs.c
index 6f85bd8..3631a3b 100644
--- a/refs.c
+++ b/refs.c
@@ -1904,18 +1904,22 @@ int refname_match(const char *abbrev_name, const char *full_name)
 	return 0;
 }
 
+/* This function should make sure errno is meaningful on error */
 static struct ref_lock *verify_lock(struct ref_lock *lock,
 	const unsigned char *old_sha1, int mustexist)
 {
 	if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
+		int save_errno = errno;
 		error("Can't verify ref %s", lock->ref_name);
 		unlock_ref(lock);
+		errno = save_errno;
 		return NULL;
 	}
 	if (hashcmp(lock->old_sha1, old_sha1)) {
 		error("Ref %s is at %s but expected %s", lock->ref_name,
 			sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
 		unlock_ref(lock);
+		errno = EBUSY;
 		return NULL;
 	}
 	return lock;
diff --git a/refs.h b/refs.h
index 979c12f..3ddd618 100644
--- a/refs.h
+++ b/refs.h
@@ -133,11 +133,15 @@ extern int ref_exists(const char *);
  */
 extern int peel_ref(const char *refname, unsigned char *sha1);
 
-/** Locks a "refs/" ref returning the lock on success and NULL on failure. **/
+/*
+ * Locks a "refs/" ref returning the lock on success and NULL on failure.
+ * On failure errno is set to something meaningfull.
+ */
 extern struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1);
 
 /** Locks any ref (for 'HEAD' type refs). */
 #define REF_NODEREF	0x01
+/* errno is set to something meaningful on failure */
 extern struct ref_lock *lock_any_ref_for_update(const char *refname,
 						const unsigned char *old_sha1,
 						int flags, int *type_p);

-- 
2.0.0.282.g3799eda.dirty
Previous: Ronnie SahlbergNext: Ronnie Sahlberg
Message 11 of 53 in “Use ref transactions”
  1. 00/48 Use ref transactionsRonnie Sahlberg, Jun 16, 2014
  2. 01/48 refs.c: remove ref_transaction_rollbackRonnie Sahlberg, Jun 16, 2014
  3. 02/48 refs.c: ref_transaction_commit should not free the transactionRonnie Sahlberg, Jun 16, 2014
  4. 03/48 refs.c: constify the sha arguments for ref_transaction_create|delete|updateRonnie Sahlberg, Jun 16, 2014
  5. 04/48 refs.c: allow passing NULL to ref_transaction_freeRonnie Sahlberg, Jun 16, 2014
  6. 05/48 refs.c: add a strbuf argument to ref_transaction_commit for error loggingRonnie Sahlberg, Jun 16, 2014
  7. 06/48 lockfile.c: add a new public function unable_to_lock_messageRonnie Sahlberg, Jun 16, 2014
  8. 07/48 lockfile.c: make lock_file return a meaningful errno on failureiRonnie Sahlberg, Jun 16, 2014
  9. 08/48 refs.c: add an err argument to repack_without_refsRonnie Sahlberg, Jun 16, 2014
  10. 09/48 refs.c: make sure log_ref_setup returns a meaningful errnoRonnie Sahlberg, Jun 16, 2014
  11. 10/48 refs.c: verify_lock should set errno to something meaningfulRonnie Sahlberg, Jun 16, 2014
  12. 11/48 refs.c: make remove_empty_directories alwasy set errno to something saneRonnie Sahlberg, Jun 16, 2014
  13. 12/48 refs.c: commit_packed_refs to return a meaningful errno on failureRonnie Sahlberg, Jun 16, 2014
  14. 13/48 refs.c: make resolve_ref_unsafe set errno to something meaningful on errorRonnie Sahlberg, Jun 16, 2014
  15. 14/48 refs.c: log_ref_write should try to return meaningful errnoRonnie Sahlberg, Jun 16, 2014
  16. 15/48 refs.c: make ref_update_reject_duplicates take a strbuf argument for errorsRonnie Sahlberg, Jun 16, 2014
  17. 16/48 refs.c: add an err argument to delete_ref_looseRonnie Sahlberg, Jun 16, 2014
  18. Junio C HamanoJun 17, 2014
  19. Ronnie SahlbergJun 17, 2014
  20. Ronnie SahlbergJun 17, 2014
  21. Junio C HamanoJun 17, 2014
  22. 17/48 refs.c: make update_ref_write update a strbuf on failureRonnie Sahlberg, Jun 16, 2014
  23. 18/48 update-ref: use err argument to get error from ref_transaction_commitRonnie Sahlberg, Jun 16, 2014
  24. 19/48 refs.c: remove the onerr argument to ref_transaction_commitRonnie Sahlberg, Jun 16, 2014
  25. 20/48 refs.c: change ref_transaction_update() to do error checking and return statusRonnie Sahlberg, Jun 16, 2014
  26. 21/48 refs.c: change ref_transaction_create to do error checking and return statusRonnie Sahlberg, Jun 16, 2014
  27. 22/48 refs.c: update ref_transaction_delete to check for error and return statusRonnie Sahlberg, Jun 16, 2014
  28. 23/48 refs.c: make ref_transaction_begin take an err argumentRonnie Sahlberg, Jun 16, 2014
  29. 24/48 refs.c: add transaction.status and track OPEN/CLOSED/ERRORRonnie Sahlberg, Jun 16, 2014
  30. 25/48 tag.c: use ref transactions when doing updatesRonnie Sahlberg, Jun 16, 2014
  31. 26/48 replace.c: use the ref transaction functions for updatesRonnie Sahlberg, Jun 16, 2014
  32. 27/48 commit.c: use ref transactions for updatesRonnie Sahlberg, Jun 16, 2014
  33. 28/48 sequencer.c: use ref transactions for all ref updatesRonnie Sahlberg, Jun 16, 2014
  34. 29/48 fast-import.c: change update_branch to use ref transactionsRonnie Sahlberg, Jun 16, 2014
  35. 30/48 branch.c: use ref transaction for all ref updatesRonnie Sahlberg, Jun 16, 2014
  36. 31/48 refs.c: change update_ref to use a transactionRonnie Sahlberg, Jun 16, 2014
  37. 32/48 receive-pack.c: use a reference transaction for updating the refsRonnie Sahlberg, Jun 16, 2014
  38. 33/48 fast-import.c: use a ref transaction when dumping tagsRonnie Sahlberg, Jun 16, 2014
  39. 34/48 walker.c: use ref transaction for ref updatesRonnie Sahlberg, Jun 16, 2014
  40. 35/48 refs.c: make lock_ref_sha1 staticRonnie Sahlberg, Jun 16, 2014
  41. 36/48 refs.c: remove the update_ref_lock functionRonnie Sahlberg, Jun 16, 2014
  42. 37/48 refs.c: remove the update_ref_write functionRonnie Sahlberg, Jun 16, 2014
  43. 38/48 refs.c: remove lock_ref_sha1Ronnie Sahlberg, Jun 16, 2014
  44. 39/48 refs.c: make prune_ref use a transaction to delete the refRonnie Sahlberg, Jun 16, 2014
  45. 40/48 refs.c: make delete_ref use a transactionRonnie Sahlberg, Jun 16, 2014
  46. 41/48 refs.c: pass the ref log message to _create/delete/update instead of _commitRonnie Sahlberg, Jun 16, 2014
  47. 42/48 refs.c: pass NULL as *flags to read_ref_fullRonnie Sahlberg, Jun 16, 2014
  48. 43/48 refs.c: move the check for valid refname to lock_ref_sha1_basicRonnie Sahlberg, Jun 16, 2014
  49. 44/48 refs.c: call lock_ref_sha1_basic directly from commitRonnie Sahlberg, Jun 16, 2014
  50. 45/48 refs.c: pass a skip list to name_conflict_fnRonnie Sahlberg, Jun 16, 2014
  51. 46/48 refs.c: propagate any errno==ENOTDIR from _commit back to the callersRonnie Sahlberg, Jun 16, 2014
  52. 47/48 fetch.c: change s_update_ref to use a ref transactionRonnie Sahlberg, Jun 16, 2014
  53. 48/48 refs.c: make write_ref_sha1 staticRonnie Sahlberg, Jun 16, 2014

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