From: Ronnie Sahlberg <sahlberg@xxxxxxxxxx>
Change refs.c to use a single transaction to perform the rename.
Change the function to return 1 on failure instead of either -1 or 1.
These changes make the rename_ref operation atomic.
Signed-off-by: Ronnie Sahlberg <sahlberg@xxxxxxxxxx>
Signed-off-by: Stefan Beller <sbeller@xxxxxxxxxx>
---
refs.c | 168 ++++++++++++++----------------------------------------
t/t3200-branch.sh | 7 ---
2 files changed, 43 insertions(+), 132 deletions(-)
diff --git a/refs.c b/refs.c
index c721184..780acd5 100644
--- a/refs.c
+++ b/refs.c
@@ -2757,60 +2757,6 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
return 0;
}
-/*
- * People using contrib's git-new-workdir have .git/logs/refs ->
- * /some/other/path/.git/logs/refs, and that may live on another device.
- *
- * IOW, to avoid cross device rename errors, the temporary renamed log must
- * live into logs/refs.
- */
-#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
-
-static int rename_tmp_log(const char *newrefname)
-{
- int attempts_remaining = 4;
-
- retry:
- switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
- 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);
- return -1;
- }
-
- if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
- 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(git_path("logs/%s", newrefname))) {
- error("Directory not empty: logs/%s", newrefname);
- return -1;
- }
- 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 {
- error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
- newrefname, strerror(errno));
- return -1;
- }
- }
- return 0;
-}
-
static int rename_ref_available(const char *oldname, const char *newname)
{
struct string_list skip = STRING_LIST_INIT_NODUP;
@@ -2859,91 +2805,63 @@ static int copy_reflog_into_strbuf(const char *refname, struct strbuf *buf)
int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
{
- unsigned char sha1[20], orig_sha1[20];
- int flag = 0, logmoved = 0;
- struct ref_lock *lock;
- struct stat loginfo;
- int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
+ unsigned char sha1[20];
+ int flag = 0;
+ int log;
+ struct transaction *transaction = NULL;
+ struct strbuf err = STRBUF_INIT;
const char *symref = NULL;
+ struct reflog_committer_info ci;
- if (log && S_ISLNK(loginfo.st_mode))
- return error("reflog for %s is a symlink", oldrefname);
+ memset(&ci, 0, sizeof(ci));
+ ci.committer_info = git_committer_info(0);
symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,
- orig_sha1, &flag);
- if (flag & REF_ISSYMREF)
- return error("refname %s is a symbolic ref, renaming it is not supported",
- oldrefname);
- if (!symref)
- return error("refname %s not found", oldrefname);
-
- if (!rename_ref_available(oldrefname, newrefname))
+ sha1, &flag);
+ if (flag & REF_ISSYMREF) {
+ error("refname %s is a symbolic ref, renaming it is not "
+ "supported", oldrefname);
return 1;
-
- if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
- return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
- oldrefname, strerror(errno));
-
- if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
- error("unable to delete old %s", oldrefname);
- goto rollback;
}
-
- if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&
- delete_ref(newrefname, sha1, REF_NODEREF)) {
- if (errno==EISDIR) {
- if (remove_empty_directories(git_path("%s", newrefname))) {
- error("Directory not empty: %s", newrefname);
- goto rollback;
- }
- } else {
- error("unable to delete existing %s", newrefname);
- goto rollback;
- }
+ if (!symref) {
+ error("refname %s not found", oldrefname);
+ return 1;
}
- if (log && rename_tmp_log(newrefname))
- goto rollback;
+ if (!rename_ref_available(oldrefname, newrefname))
+ return 1;
- logmoved = log;
+ log = reflog_exists(oldrefname);
- lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL);
- if (!lock) {
- error("unable to lock %s for update", newrefname);
- goto rollback;
- }
- lock->force_write = 1;
- hashcpy(lock->old_sha1, orig_sha1);
- if (write_ref_sha1(lock, orig_sha1, logmsg)) {
- error("unable to write current sha1 into %s", newrefname);
- goto rollback;
+ transaction = transaction_begin(&err);
+ if (!transaction)
+ goto fail;
+
+ if (strcmp(oldrefname, newrefname)) {
+ if (transaction_delete_ref(transaction, oldrefname, sha1,
+ REF_NODEREF, 1, NULL, &err))
+ goto fail;
+ if (log && transaction_rename_reflog(transaction, oldrefname,
+ newrefname, &err))
+ goto fail;
+ if (log && transaction_update_reflog(transaction, newrefname,
+ sha1, sha1, &ci, logmsg,
+ REFLOG_COMMITTER_INFO_IS_VALID, &err))
+ goto fail;
}
+ if (transaction_update_ref(transaction, newrefname, sha1,
+ NULL, 0, 0, NULL, &err))
+ goto fail;
+ if (transaction_commit(transaction, &err))
+ goto fail;
+ transaction_free(transaction);
return 0;
- rollback:
- lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL);
- if (!lock) {
- error("unable to lock %s for rollback", oldrefname);
- goto rollbacklog;
- }
-
- lock->force_write = 1;
- flag = log_all_ref_updates;
- log_all_ref_updates = 0;
- if (write_ref_sha1(lock, orig_sha1, NULL))
- error("unable to write current sha1 into %s", oldrefname);
- log_all_ref_updates = flag;
-
- rollbacklog:
- if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
- error("unable to restore logfile %s from %s: %s",
- oldrefname, newrefname, strerror(errno));
- if (!logmoved && log &&
- rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
- error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
- oldrefname, strerror(errno));
-
+ fail:
+ error("rename_ref failed: %s", err.buf);
+ strbuf_release(&err);
+ transaction_free(transaction);
return 1;
}
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index 432921b..c6c53e4 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -302,13 +302,6 @@ test_expect_success 'renaming a symref is not allowed' '
test_path_is_missing .git/refs/heads/master3
'
-test_expect_success SYMLINKS 'git branch -m u v should fail when the reflog for u is a symlink' '
- git branch -l u &&
- mv .git/logs/refs/heads/u real-u &&
- ln -s real-u .git/logs/refs/heads/u &&
- test_must_fail git branch -m u v
-'
-
test_expect_success 'test tracking setup via --track' '
git config remote.local.url . &&
git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
--
2.2.0.rc2.5.gf7b9fb2
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