walker.c: use ref transaction for ref updates
Switch to using ref transactions in walker_fetch(). As part of the refactoring to use ref transactions we also fix a potential memory leak where in the original code if write_ref_sha1() would fail we would end up returning from the function without free()ing the msg string. Note that this function is only called when fetching from a remote HTTP repository onto the local (most of the time single-user) repository which likely means that the type of collisions that the previous locking would protect against and cause the fetch to fail for are even more rare. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ronnie Sahlberg committed
Apr 17, 2014 at 11:31 UTC
b6b10bb44c31b5a830c1636c7eb8b122f9b67858
1 file changed
+40
-30
walker.c
+40
-30
@@ -251,40 +251,40 @@ void walker_targets_free(int targets, char **target, const char **write_ref)
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int walker_fetch(struct walker *walker, int targets, char **target,
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const char **write_ref, const char *write_ref_log_details)
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{
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- struct ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
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+ struct strbuf refname = STRBUF_INIT;
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+ struct strbuf err = STRBUF_INIT;
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+ struct ref_transaction *transaction = NULL;
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unsigned char *sha1 = xmalloc(targets * 20);
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- char *msg;
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- int ret;
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- int i;
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+ char *msg = NULL;
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+ int i, ret = -1;
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save_commit_buffer = 0;
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- for (i = 0; i < targets; i++) {
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- if (!write_ref || !write_ref[i])
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- continue;
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-
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- lock[i] = lock_ref_sha1(write_ref[i], NULL);
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- if (!lock[i]) {
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- error("Can't lock ref %s", write_ref[i]);
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- goto unlock_and_fail;
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+ if (write_ref) {
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+ transaction = ref_transaction_begin(&err);
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+ if (!transaction) {
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+ error("%s", err.buf);
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+ goto done;
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}
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}
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-
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if (!walker->get_recover)
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for_each_ref(mark_complete, NULL);
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for (i = 0; i < targets; i++) {
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if (interpret_target(walker, target[i], &sha1[20 * i])) {
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error("Could not interpret response from server '%s' as something to pull", target[i]);
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- goto unlock_and_fail;
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+ goto done;
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}
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if (process(walker, lookup_unknown_object(&sha1[20 * i])))
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- goto unlock_and_fail;
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+ goto done;
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}
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if (loop(walker))
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- goto unlock_and_fail;
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-
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+ goto done;
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+ if (!write_ref) {
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+ ret = 0;
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+ goto done;
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+ }
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if (write_ref_log_details) {
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msg = xmalloc(strlen(write_ref_log_details) + 12);
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sprintf(msg, "fetch from %s", write_ref_log_details);
@@ -292,23 +292,33 @@ int walker_fetch(struct walker *walker, int targets, char **target,
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msg = NULL;
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}
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for (i = 0; i < targets; i++) {
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- if (!write_ref || !write_ref[i])
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+ if (!write_ref[i])
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continue;
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- ret = write_ref_sha1(lock[i], &sha1[20 * i], msg ? msg : "fetch (unknown)");
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- lock[i] = NULL;
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- if (ret)
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- goto unlock_and_fail;
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+ strbuf_reset(&refname);
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+ strbuf_addf(&refname, "refs/%s", write_ref[i]);
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+ if (ref_transaction_update(transaction, refname.buf,
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+ &sha1[20 * i], NULL, 0, 0,
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+ &err)) {
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+ error("%s", err.buf);
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+ goto done;
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+ }
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+ }
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+ if (ref_transaction_commit(transaction,
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+ msg ? msg : "fetch (unknown)",
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+ &err)) {
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+ error("%s", err.buf);
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+ goto done;
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}
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- free(msg);
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-
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- return 0;
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-unlock_and_fail:
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- for (i = 0; i < targets; i++)
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- if (lock[i])
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- unlock_ref(lock[i]);
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+ ret = 0;
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- return -1;
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+done:
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+ ref_transaction_free(transaction);
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+ free(msg);
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+ free(sha1);
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+ strbuf_release(&err);
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+ strbuf_release(&refname);
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+ return ret;
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}
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void walker_free(struct walker *walker)