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List:       git
Subject:    [PATCH v3 08/23] rename_tmp_log(): use raceproof_create_file()
From:       Michael Haggerty <mhagger () alum ! mit ! edu>
Date:       2016-12-31 3:12:48
Message-ID: 75f51a671ed56bff55906c6f9400d53dfe8199c9.1483153436.git.mhagger () alum ! mit ! edu
[Download RAW message or body]

Besides shortening the code, this saves an unnecessary call to
safe_create_leading_directories_const() in almost all cases.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 refs/files-backend.c | 73 +++++++++++++++++++++-------------------------------
 1 file changed, 30 insertions(+), 43 deletions(-)

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 74de289..3f18a01 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2489,55 +2489,42 @@ static int files_delete_refs(struct ref_store *ref_store,
  */
 #define TMP_RENAMED_LOG  "logs/refs/.tmp-renamed-log"
 
-static int rename_tmp_log(const char *newrefname)
+static int rename_tmp_log_callback(const char *path, void *cb)
 {
-	int attempts_remaining = 4;
-	struct strbuf path = STRBUF_INIT;
-	int ret = -1;
+	int *true_errno = cb;
 
- retry:
-	strbuf_reset(&path);
-	strbuf_git_path(&path, "logs/%s", newrefname);
-	switch (safe_create_leading_directories_const(path.buf)) {
-	case SCLD_OK:
-		break; /* success */
-	case SCLD_VANISHED:
-		if (--attempts_remaining > 0)
-			goto retry;
-		/* fall through */
-	default:
-		error("unable to create directory for %s", newrefname);
-		goto out;
+	if (rename(git_path(TMP_RENAMED_LOG), path)) {
+		/*
+		 * rename(a, b) when b is an existing directory ought
+		 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.
+		 * Sheesh. Record the true errno for error reporting,
+		 * but report EISDIR to raceproof_create_file() so
+		 * that it knows to retry.
+		 */
+		*true_errno = errno;
+		if (errno == ENOTDIR)
+			errno = EISDIR;
+		return -1;
+	} else {
+		return 0;
 	}
+}
 
-	if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {
-		if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
-			/*
-			 * rename(a, b) when b is an existing
-			 * directory ought to result in ISDIR, but
-			 * Solaris 5.8 gives ENOTDIR.  Sheesh.
-			 */
-			if (remove_empty_directories(&path)) {
-				error("Directory not empty: logs/%s", newrefname);
-				goto out;
-			}
-			goto retry;
-		} else if (errno == ENOENT && --attempts_remaining > 0) {
-			/*
-			 * Maybe another process just deleted one of
-			 * the directories in the path to newrefname.
-			 * Try again from the beginning.
-			 */
-			goto retry;
-		} else {
+static int rename_tmp_log(const char *newrefname)
+{
+	char *path = git_pathdup("logs/%s", newrefname);
+	int ret, true_errno;
+
+	ret = raceproof_create_file(path, rename_tmp_log_callback, &true_errno);
+	if (ret) {
+		if (errno == EISDIR)
+			error("Directory not empty: %s", path);
+		else
 			error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
-				newrefname, strerror(errno));
-			goto out;
-		}
+				newrefname, strerror(true_errno));
 	}
-	ret = 0;
-out:
-	strbuf_release(&path);
+
+	free(path);
 	return ret;
 }
 
-- 
2.9.3

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