From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Turner Subject: [PATCH v6 22/32] refs: always handle non-normal refs in files backend Date: Wed, 24 Feb 2016 17:58:54 -0500 Message-ID: <1456354744-8022-23-git-send-email-dturner@twopensource.com> References: <1456354744-8022-1-git-send-email-dturner@twopensource.com> Cc: David Turner To: git@vger.kernel.org, mhagger@alum.mit.edu, pclouds@gmail.com X-From: git-owner@vger.kernel.org Thu Feb 25 00:01:05 2016 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1aYiQa-0004iM-A0 for gcvg-git-2@plane.gmane.org; Thu, 25 Feb 2016 00:01:04 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759265AbcBXXAv (ORCPT ); Wed, 24 Feb 2016 18:00:51 -0500 Received: from mail-qg0-f49.google.com ([209.85.192.49]:36106 "EHLO mail-qg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759185AbcBXW7j (ORCPT ); Wed, 24 Feb 2016 17:59:39 -0500 Received: by mail-qg0-f49.google.com with SMTP id y9so27394957qgd.3 for ; Wed, 24 Feb 2016 14:59:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=twopensource-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=cejP78Z/QbYtRgzXwldOCihij1gGg+XgLcSLZZqAPkg=; b=Tm6OEG4AL+m9FGykySg7q37tIAtym/pG5okibHHT6jshK67xj4mGJnDZpz+3XV1faZ ihujRLFrYN2/AEJiYNW6eEuIe6T1/38mJu/24hamgoxE4SpHBtseuXXKJRBjNaENWvRn UEWM9NlYxeAqYdcCnqB5rKQH9ejPEghzZoVxfOpAEZRgo37DlY16dgKuPrq1jn5i5odB jlCeVJ2ueVRiglbaufzf9T0yQuy7gw7zy7Bd0GHLSPEj3DVV+k1D0LRj8GzjEViLiQtK PYkpbbIpiW6IzWjJncQXOJf3iDLaISLCNup+qr4HH1YjtEt5u7sRRrvd09f8JUYO5KfN L4JA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=cejP78Z/QbYtRgzXwldOCihij1gGg+XgLcSLZZqAPkg=; b=H255BGAiNeT1yRicEvbToiR0dajwrorJOuQnJ1CC/y9AHFgpnoSNUfwAXL8wMlEjqU 98dTbJ2y17t4rBUVotuYdhPK1MET+fgXZ9Yl6AYVer7AxvuZuaPpSKIxS0kBOPTr2kpw +Ag1B7AIrkImlO0b9b25217DOQd+dyYlKom7kucBKzrpNDz3MmS3HAueLbtvNz2wVjIb OYAEJuwLKuXDQb4rd+MrDpyPwc/QNU0DI129uadUU5EsvN6Zu8zCJKawq5Vxw8kYZhHi ojfgXYMEHyFt6lmY4Cy/pYI8lA7PQvwosbusr77iX9EoCPaiM87iRw7J5wyZQ4HKmHco Dokw== X-Gm-Message-State: AG10YORpN4eIkSdmBjmYJpcmjtUxJYHR9rj6T6faNYKuqJSlpyEXBckNfBh65MbLfpWWlQ== X-Received: by 10.140.131.17 with SMTP id 17mr55210752qhd.12.1456354778998; Wed, 24 Feb 2016 14:59:38 -0800 (PST) Received: from ubuntu.twitter.biz ([192.133.79.145]) by smtp.gmail.com with ESMTPSA id 66sm2154254qhp.4.2016.02.24.14.59.37 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 24 Feb 2016 14:59:37 -0800 (PST) X-Mailer: git-send-email 2.4.2.767.g62658d5-twtrsrc In-Reply-To: <1456354744-8022-1-git-send-email-dturner@twopensource.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Always handle non-normal (per-worktree or pseudo) refs in the files backend instead of alternate backends. Sometimes a ref transaction will update both a per-worktree ref and a normal ref. For instance, an ordinary commit might update refs/heads/master and HEAD (or at least HEAD's reflog). Updates to normal refs continue to go through the chosen backend. Updates to non-normal refs are moved to a separate files backend transaction. Signed-off-by: David Turner --- refs.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 90 insertions(+), 20 deletions(-) diff --git a/refs.c b/refs.c index bdde808..b2acf0e 100644 --- a/refs.c +++ b/refs.c @@ -9,6 +9,11 @@ #include "object.h" #include "tag.h" +static const char split_transaction_fail_warning[] = N_( + "A ref transaction was split across two refs backends. Part of the " + "transaction succeeded, but then the update to the per-worktree refs " + "failed. Your repository may be in an inconsistent state."); + /* * We always have a files backend and it is the default. */ @@ -791,6 +796,13 @@ void ref_transaction_free(struct ref_transaction *transaction) free(transaction); } +static void add_update_obj(struct ref_transaction *transaction, + struct ref_update *update) +{ + ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc); + transaction->updates[transaction->nr++] = update; +} + static struct ref_update *add_update(struct ref_transaction *transaction, const char *refname) { @@ -798,8 +810,7 @@ static struct ref_update *add_update(struct ref_transaction *transaction, struct ref_update *update = xcalloc(1, sizeof(*update) + len); memcpy((char *)update->refname, refname, len); /* includes NUL */ - ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc); - transaction->updates[transaction->nr++] = update; + add_update_obj(transaction, update); return update; } @@ -1416,11 +1427,37 @@ static int dereference_symrefs(struct ref_transaction *transaction, return 0; } -int ref_transaction_commit(struct ref_transaction *transaction, - struct strbuf *err) +/* + * Move all non-normal ref updates into a specially-created + * files-backend transaction + */ +static int move_abnormal_ref_updates(struct ref_transaction *transaction, + struct ref_transaction *files_transaction, + struct strbuf *err) +{ + int i, normal_nr = 0; + + for (i = 0; i < transaction->nr; i++) { + struct ref_update *update = transaction->updates[i]; + + if (ref_type(update->refname) == REF_TYPE_NORMAL) + transaction->updates[normal_nr++] = update; + else + add_update_obj(files_transaction, update); + } + + transaction->nr = normal_nr; + return 0; +} + +static int do_ref_transaction_commit(struct ref_transaction *transaction, + struct strbuf *err, + ref_transaction_commit_fn *commit_fn) { int ret = -1; struct string_list affected_refnames = STRING_LIST_INIT_NODUP; + struct string_list files_affected_refnames = STRING_LIST_INIT_NODUP; + struct ref_transaction *files_transaction = NULL; assert(err); @@ -1436,18 +1473,60 @@ int ref_transaction_commit(struct ref_transaction *transaction, if (ret) goto done; + if (the_refs_backend != &refs_be_files) { + files_transaction = ref_transaction_begin(err); + if (!files_transaction) + goto done; + + ret = move_abnormal_ref_updates(transaction, files_transaction, + err); + if (ret) + goto done; + + /* files backend commit */ + if (get_affected_refnames(files_transaction, + &files_affected_refnames, + err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto done; + } + } + + /* main backend commit */ if (get_affected_refnames(transaction, &affected_refnames, err)) { ret = TRANSACTION_GENERIC_ERROR; goto done; } - ret = the_refs_backend->transaction_commit(transaction, - &affected_refnames, err); + ret = commit_fn(transaction, &affected_refnames, err); + if (ret) + goto done; + + if (files_transaction) { + ret = refs_be_files.transaction_commit(files_transaction, + &files_affected_refnames, + err); + if (ret) { + warning(split_transaction_fail_warning); + goto done; + } + } + done: string_list_clear(&affected_refnames, 0); + string_list_clear(&files_affected_refnames, 0); + if (files_transaction) + ref_transaction_free(files_transaction); return ret; } +int ref_transaction_commit(struct ref_transaction *transaction, + struct strbuf *err) +{ + return do_ref_transaction_commit(transaction, err, + the_refs_backend->transaction_commit); +} + int verify_refname_available(const char *refname, struct string_list *extra, struct string_list *skip, struct strbuf *err) { @@ -1467,6 +1546,9 @@ int peel_ref(const char *refname, unsigned char *sha1) int create_symref(const char *ref_target, const char *refs_heads_master, const char *logmsg) { + if (ref_type(ref_target) != REF_TYPE_NORMAL) + return refs_be_files.create_symref(ref_target, refs_heads_master, + logmsg); return the_refs_backend->create_symref(ref_target, refs_heads_master, logmsg); } @@ -1526,20 +1608,8 @@ int reflog_expire(const char *refname, const unsigned char *sha1, int initial_ref_transaction_commit(struct ref_transaction *transaction, struct strbuf *err) { - struct string_list affected_refnames = STRING_LIST_INIT_NODUP; - int ret; - - if (get_affected_refnames(transaction, - &affected_refnames, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto done; - } - ret = the_refs_backend->initial_transaction_commit(transaction, - &affected_refnames, - err); -done: - string_list_clear(&affected_refnames, 0); - return ret; + return do_ref_transaction_commit(transaction, err, + the_refs_backend->initial_transaction_commit); } int delete_refs(struct string_list *refnames) -- 2.4.2.767.g62658d5-twtrsrc