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

[PATCH v3 11/17] lock_ref_sha1_basic(): if locking fails with ENOENT, retry

From
Michael Haggerty <mhagger@alum.mit.edu>
Date
Jan 18, 2014, 22:48 UTC
Message-ID
<1390085341-2553-12-git-send-email-mhagger@alum.mit.edu>
In-Reply-To
<1390085341-2553-1-git-send-email-mhagger@alum.mit.edu>

If hold_lock_file_for_update() fails with errno==ENOENT, it might be because somebody else (for example, a pack-refs process) has just deleted one of the lockfile's ancestor directories. So if this condition is detected, try again (up to 3 times).

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 refs.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/refs.c b/refs.c
index 9ae184d..4060ed1 100644
--- a/refs.c
+++ b/refs.c
@@ -2081,7 +2081,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 
 	lock->lk = xcalloc(1, sizeof(struct lock_file));
 
-	lflags = LOCK_DIE_ON_ERROR;
+	lflags = 0;
 	if (flags & REF_NODEREF) {
 		refname = orig_refname;
 		lflags |= LOCK_NODEREF;
@@ -2109,6 +2109,17 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	}
 
 	lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
+	if (lock->lock_fd < 0) {
+		if (errno == ENOENT && --attempts_remaining > 0)
+			/*
+			 * Maybe somebody just deleted one of the
+			 * directories leading to ref_file.  Try
+			 * again:
+			 */
+			goto retry;
+		else
+			unable_to_lock_index_die(ref_file, errno);
+	}
 	return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
 
  error_return:

-- 
1.8.5.2
Previous: Michael HaggertyNext: Michael Haggerty
Message 12 of 18 in “Fix some mkdir/rmdir races”
  1. 00/17 Fix some mkdir/rmdir racesMichael Haggerty, Jan 18, 2014
  2. 01/17 safe_create_leading_directories(): fix format of "if" chainingMichael Haggerty, Jan 18, 2014
  3. 02/17 safe_create_leading_directories(): reduce scope of local variableMichael Haggerty, Jan 18, 2014
  4. 03/17 safe_create_leading_directories(): add explicit "slash" pointerMichael Haggerty, Jan 18, 2014
  5. 04/17 safe_create_leading_directories(): rename local variableMichael Haggerty, Jan 18, 2014
  6. 05/17 safe_create_leading_directories(): split on first of multiple slashesMichael Haggerty, Jan 18, 2014
  7. 06/17 safe_create_leading_directories(): always restore slash at end of loopMichael Haggerty, Jan 18, 2014
  8. 07/17 safe_create_leading_directories(): introduce enum for return valuesMichael Haggerty, Jan 18, 2014
  9. 08/17 cmd_init_db(): when creating directories, handle errors conservativelyMichael Haggerty, Jan 18, 2014
  10. 09/17 safe_create_leading_directories(): add new error value SCLD_VANISHEDMichael Haggerty, Jan 18, 2014
  11. 10/17 lock_ref_sha1_basic(): on SCLD_VANISHED, retryMichael Haggerty, Jan 18, 2014
  12. 11/17 lock_ref_sha1_basic(): if locking fails with ENOENT, retryMichael Haggerty, Jan 18, 2014
  13. 12/17 remove_dir_recurse(): tighten condition for removing unreadable dirMichael Haggerty, Jan 18, 2014
  14. 13/17 remove_dir_recurse(): handle disappearing files and directoriesMichael Haggerty, Jan 18, 2014
  15. 14/17 rename_ref(): extract function rename_tmp_log()Michael Haggerty, Jan 18, 2014
  16. 15/17 rename_tmp_log(): handle a possible mkdir/rmdir raceMichael Haggerty, Jan 18, 2014
  17. 16/17 rename_tmp_log(): limit the number of remote_empty_directories() attemptsMichael Haggerty, Jan 18, 2014
  18. 17/17 rename_tmp_log(): on SCLD_VANISHED, retryMichael Haggerty, Jan 18, 2014

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.