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[PATCH v15 07/48] lockfile.c: make lock_file return a meaningful errno on failurei

From
Ronnie Sahlberg <sahlberg@google.com>
Date
Jun 10, 2014, 22:28 UTC
Message-ID
<1402439376-25839-8-git-send-email-sahlberg@google.com>
In-Reply-To
<1402439376-25839-1-git-send-email-sahlberg@google.com>

Making errno when returning from lock_file() meaningful, which should fix

 * an existing almost-bug in lock_ref_sha1_basic where it assumes
   errno==ENOENT is meaningful and could waste some work on retries
 * an existing bug in repack_without_refs where it prints
   strerror(errno) and picks advice based on errno, despite errno
   potentially being zero and potentially having been clobbered by
   that point
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 lockfile.c | 17 ++++++++++++-----
 refs.c     |  1 +
 refs.h     |  1 +
 3 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/lockfile.c b/lockfile.c
index 464031b..a921d77 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -121,7 +121,7 @@ static char *resolve_symlink(char *p, size_t s)
 	return p;
 }
 
-
+/* Make sure errno contains a meaningful value on error */
 static int lock_file(struct lock_file *lk, const char *path, int flags)
 {
 	/*
@@ -130,8 +130,10 @@ static int lock_file(struct lock_file *lk, const char *path, int flags)
 	 */
 	static const size_t max_path_len = sizeof(lk->filename) - 5;
 
-	if (strlen(path) >= max_path_len)
+	if (strlen(path) >= max_path_len) {
+		errno = ENAMETOOLONG;
 		return -1;
+	}
 	strcpy(lk->filename, path);
 	if (!(flags & LOCK_NODEREF))
 		resolve_symlink(lk->filename, max_path_len);
@@ -148,9 +150,13 @@ static int lock_file(struct lock_file *lk, const char *path, int flags)
 			lock_file_list = lk;
 			lk->on_list = 1;
 		}
-		if (adjust_shared_perm(lk->filename))
-			return error("cannot fix permission bits on %s",
-				     lk->filename);
+		if (adjust_shared_perm(lk->filename)) {
+			int save_errno = errno;
+			error("cannot fix permission bits on %s",
+			      lk->filename);
+			errno = save_errno;
+			return -1;
+		}
 	}
 	else
 		lk->filename[0] = 0;
@@ -188,6 +194,7 @@ NORETURN void unable_to_lock_index_die(const char *path, int err)
 	die("%s", buf.buf);
 }
 
+/* This should return a meaningful errno on failure */
 int hold_lock_file_for_update(struct lock_file *lk, const char *path, int flags)
 {
 	int fd = lock_file(lk, path, flags);
diff --git a/refs.c b/refs.c
index 25c3a93..1e8f293 100644
--- a/refs.c
+++ b/refs.c
@@ -2184,6 +2184,7 @@ static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
 	return 0;
 }
 
+/* This should return a meaningful errno on failure */
 int lock_packed_refs(int flags)
 {
 	struct packed_ref_cache *packed_ref_cache;
diff --git a/refs.h b/refs.h
index 94d4cd4..948cc53 100644
--- a/refs.h
+++ b/refs.h
@@ -81,6 +81,7 @@ extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refn
 /*
  * Lock the packed-refs file for writing.  Flags is passed to
  * hold_lock_file_for_update().  Return 0 on success.
+ * Errno is set to something meaningful on error.
  */
 extern int lock_packed_refs(int flags);
 

-- 
2.0.0.574.g30c2c5e
Previous: Ronnie SahlbergNext: Ronnie Sahlberg
Message 8 of 51 in “Use ref transactions”
  1. 00/48 Use ref transactionsRonnie Sahlberg, Jun 10, 2014
  2. 01/48 refs.c: remove ref_transaction_rollbackRonnie Sahlberg, Jun 10, 2014
  3. 02/48 refs.c: ref_transaction_commit should not free the transactionRonnie Sahlberg, Jun 10, 2014
  4. 03/48 refs.c: constify the sha arguments for ref_transaction_create|delete|updateRonnie Sahlberg, Jun 10, 2014
  5. 04/48 refs.c: allow passing NULL to ref_transaction_freeRonnie Sahlberg, Jun 10, 2014
  6. 05/48 refs.c: add a strbuf argument to ref_transaction_commit for error loggingRonnie Sahlberg, Jun 10, 2014
  7. 06/48 lockfile.c: add a new public function unable_to_lock_messageRonnie Sahlberg, Jun 10, 2014
  8. 07/48 lockfile.c: make lock_file return a meaningful errno on failureiRonnie Sahlberg, Jun 10, 2014
  9. 08/48 refs.c: add an err argument to repack_without_refsRonnie Sahlberg, Jun 10, 2014
  10. 09/48 refs.c: make sure log_ref_setup returns a meaningful errnoRonnie Sahlberg, Jun 10, 2014
  11. 10/48 refs.c: verify_lock should set errno to something meaningfulRonnie Sahlberg, Jun 10, 2014
  12. 11/48 refs.c: make remove_empty_directories alwasy set errno to something saneRonnie Sahlberg, Jun 10, 2014
  13. 12/48 refs.c: commit_packed_refs to return a meaningful errno on failureRonnie Sahlberg, Jun 10, 2014
  14. 13/48 refs.c: make resolve_ref_unsafe set errno to something meaningful on errorRonnie Sahlberg, Jun 10, 2014
  15. 14/48 refs.c: log_ref_write should try to return meaningful errnoRonnie Sahlberg, Jun 10, 2014
  16. 15/48 refs.c: make ref_update_reject_duplicates take a strbuf argument for errorsRonnie Sahlberg, Jun 10, 2014
  17. 16/48 refs.c: add an err argument to delete_ref_looseRonnie Sahlberg, Jun 10, 2014
  18. 17/48 refs.c: make update_ref_write update a strbuf on failureRonnie Sahlberg, Jun 10, 2014
  19. 18/48 update-ref: use err argument to get error from ref_transaction_commitRonnie Sahlberg, Jun 10, 2014
  20. 19/48 refs.c: remove the onerr argument to ref_transaction_commitRonnie Sahlberg, Jun 10, 2014
  21. 20/48 refs.c: change ref_transaction_update() to do error checking and return statusRonnie Sahlberg, Jun 10, 2014
  22. 21/48 refs.c: change ref_transaction_create to do error checking and return statusRonnie Sahlberg, Jun 10, 2014
  23. 22/48 refs.c: update ref_transaction_delete to check for error and return statusRonnie Sahlberg, Jun 10, 2014
  24. 23/48 refs.c: make ref_transaction_begin take an err argumentRonnie Sahlberg, Jun 10, 2014
  25. 24/48 refs.c: add transaction.status and track OPEN/CLOSED/ERRORRonnie Sahlberg, Jun 10, 2014
  26. 25/48 tag.c: use ref transactions when doing updatesRonnie Sahlberg, Jun 10, 2014
  27. 26/48 replace.c: use the ref transaction functions for updatesRonnie Sahlberg, Jun 10, 2014
  28. 27/48 commit.c: use ref transactions for updatesRonnie Sahlberg, Jun 10, 2014
  29. 28/48 sequencer.c: use ref transactions for all ref updatesRonnie Sahlberg, Jun 10, 2014
  30. 29/48 fast-import.c: change update_branch to use ref transactionsRonnie Sahlberg, Jun 10, 2014
  31. 30/48 branch.c: use ref transaction for all ref updatesRonnie Sahlberg, Jun 10, 2014
  32. 31/48 refs.c: change update_ref to use a transactionRonnie Sahlberg, Jun 10, 2014
  33. 32/48 receive-pack.c: use a reference transaction for updating the refsRonnie Sahlberg, Jun 10, 2014
  34. 33/48 fast-import.c: use a ref transaction when dumping tagsRonnie Sahlberg, Jun 10, 2014
  35. 34/48 walker.c: use ref transaction for ref updatesRonnie Sahlberg, Jun 10, 2014
  36. 35/48 refs.c: make lock_ref_sha1 staticRonnie Sahlberg, Jun 10, 2014
  37. 36/48 refs.c: remove the update_ref_lock functionRonnie Sahlberg, Jun 10, 2014
  38. 37/48 refs.c: remove the update_ref_write functionRonnie Sahlberg, Jun 10, 2014
  39. 38/48 refs.c: remove lock_ref_sha1Ronnie Sahlberg, Jun 10, 2014
  40. 39/48 refs.c: make prune_ref use a transaction to delete the refRonnie Sahlberg, Jun 10, 2014
  41. 40/48 refs.c: make delete_ref use a transactionRonnie Sahlberg, Jun 10, 2014
  42. 41/48 refs.c: pass the ref log message to _create/delete/update instead of _commitRonnie Sahlberg, Jun 10, 2014
  43. 42/48 refs.c: pass NULL as *flags to read_ref_fullRonnie Sahlberg, Jun 10, 2014
  44. 43/48 refs.c: move the check for valid refname to lock_ref_sha1_basicRonnie Sahlberg, Jun 10, 2014
  45. 44/48 refs.c: call lock_ref_sha1_basic directly from commitRonnie Sahlberg, Jun 10, 2014
  46. 45/48 refs.c: pass a skip list to name_conflict_fnRonnie Sahlberg, Jun 10, 2014
  47. 46/48 refs.c: propagate any errno==ENOTDIR from _commit back to the callersRonnie Sahlberg, Jun 10, 2014
  48. 47/48 fetch.c: change s_update_ref to use a ref transactionRonnie Sahlberg, Jun 10, 2014
  49. 48/48 refs.c: make write_ref_sha1 staticRonnie Sahlberg, Jun 10, 2014
  50. Junio C HamanoJun 12, 2014
  51. Ronnie SahlbergJun 13, 2014

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