From patchwork Tue Sep 28 23:32:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Neeraj Singh (WINDOWS-SFS)" X-Patchwork-Id: 12524059 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CD55C433FE for ; Tue, 28 Sep 2021 23:32:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D12F6136F for ; Tue, 28 Sep 2021 23:32:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243269AbhI1Xeg (ORCPT ); Tue, 28 Sep 2021 19:34:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243252AbhI1Xef (ORCPT ); Tue, 28 Sep 2021 19:34:35 -0400 Received: from mail-wr1-x42b.google.com (mail-wr1-x42b.google.com [IPv6:2a00:1450:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6755C061745 for ; Tue, 28 Sep 2021 16:32:54 -0700 (PDT) Received: by mail-wr1-x42b.google.com with SMTP id t8so1124507wrq.4 for ; Tue, 28 Sep 2021 16:32:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=AYmz+hgZbrQEWyt17kXMMD7aehTe8Mt5waObK2M5wgY=; b=TmquAGcS4hYXxqUWm3LAwxXshcCimPBdvHLPHt6z9T5XNFIl5K2CvH/EcaTd7LBD5G 8fKFfWYuzEwY3WftI8VtvM+Qqe73cbl1sVkD/OEhwMzCg8D4POhHrnnlnn+6VPM2W2dl GbdX59CPwNyzV9CmkIB7RKl4QYqEn8aKONva8rwsdyGN8yg2DVyF3QjGTFA9g/c4TvU7 I4AImBnOzdlAgAOHWKnKXSXWF9W8NyYyJezo23Tf/kQf25em1XrryiMLTnaknZzJXiAh +zw96zanUFx2X32aiifECIv42wewAcgg1f0kYiJubIsoHyWwE9t1QfqH35zm9Y7OVOCb OQ0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=AYmz+hgZbrQEWyt17kXMMD7aehTe8Mt5waObK2M5wgY=; b=8NQjKBueTIW7R3g2Tpx4uOS3X1179lbdocWjrD2H9E6K7ablZh474PkEqI1+ClMN4P NM3HnetNajknhCqmgmq3+YXG0Wgd7v/yA6sNLZFapq2gFOUNkofkAv89Ac/+xBJ/4yrK O61nyYiOej0hVjA1bOv4ZyNT9YqmrZha5W+dRiYQxYWu/TQjgqGJ0qtJ4vYOXlQEyEcb BWWC0xwVEaYLU4CgqMx4NKfQIJLkzs0qG2o4obEUbo3WkiP8kbLwFT+YX2ZfU9J6nY1G urbirmfUiWcA8rZCMoauO3WrYpnyHI/FqjBxtKujxPXnmdqyEcAU3yLqvW8x2jqApvuF 4TYw== X-Gm-Message-State: AOAM530hOayHXxWtFwU9a52e5J/6fE2jBSo1XlhBAwfT2yVcFPe1GPu1 AhCVkrKO/q3vORhgcEB3X1+OFAK8GF8= X-Google-Smtp-Source: ABdhPJyTb8XSSEPhQvYmUCUC6zfqSiuJ3MAtBaaO7G6WnWxwl+urwOflrsQLUl41FVjB9bmacELFwg== X-Received: by 2002:adf:e8cb:: with SMTP id k11mr3161832wrn.435.1632871973457; Tue, 28 Sep 2021 16:32:53 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id f1sm515547wri.43.2021.09.28.16.32.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Sep 2021 16:32:53 -0700 (PDT) Message-Id: <6e65f68fd6d4d90b0a7bca2e2e57ace9ad749266.1632871971.git.gitgitgadget@gmail.com> In-Reply-To: References: Date: Tue, 28 Sep 2021 23:32:43 +0000 Subject: [PATCH v7 1/9] object-file.c: do not rename in a temp odb Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Neeraj-Personal , Johannes Schindelin , Jeff King , Jeff Hostetler , Christoph Hellwig , =?utf-8?b?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason , "Randall S. Becker" , Bagas Sanjaya , "Neeraj K. Singh" , Neeraj Singh Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Neeraj Singh From: Neeraj Singh If a temporary ODB is active, as determined by GIT_QUARANTINE_PATH being set, create object files with their final names. This avoids an extra rename beyond what is needed to merge the temporary ODB in tmp_objdir_migrate. Creating an object file with the expected final name should be okay since the git process writing to the temporary object store is the only writer, and it only invokes write_loose_object/create_object_file after checking that the object doesn't exist. Signed-off-by: Neeraj Singh --- environment.c | 4 ++++ object-file.c | 51 ++++++++++++++++++++++++++++++++++---------------- object-store.h | 6 ++++++ repository.c | 2 ++ repository.h | 1 + 5 files changed, 48 insertions(+), 16 deletions(-) diff --git a/environment.c b/environment.c index b4ba4fa22db..30fca67e6d6 100644 --- a/environment.c +++ b/environment.c @@ -176,6 +176,10 @@ void setup_git_env(const char *git_dir) args.graft_file = getenv_safe(&to_free, GRAFT_ENVIRONMENT); args.index_file = getenv_safe(&to_free, INDEX_ENVIRONMENT); args.alternate_db = getenv_safe(&to_free, ALTERNATE_DB_ENVIRONMENT); + if (getenv(GIT_QUARANTINE_ENVIRONMENT)) { + args.object_dir_is_temp = 1; + } + repo_set_gitdir(the_repository, git_dir, &args); strvec_clear(&to_free); diff --git a/object-file.c b/object-file.c index be4f94ecf3b..49c53f801f7 100644 --- a/object-file.c +++ b/object-file.c @@ -1826,12 +1826,17 @@ static void write_object_file_prepare(const struct git_hash_algo *algo, } /* - * Move the just written object into its final resting place. + * Move the just written object into its final resting place, + * unless it is already there, as indicated by an empty string for + * tmpfile. */ int finalize_object_file(const char *tmpfile, const char *filename) { int ret = 0; + if (!*tmpfile) + goto out; + if (object_creation_mode == OBJECT_CREATION_USES_RENAMES) goto try_rename; else if (link(tmpfile, filename)) @@ -1904,21 +1909,37 @@ static inline int directory_size(const char *filename) } /* - * This creates a temporary file in the same directory as the final - * 'filename' + * This creates a loose object file for the specified object id. + * If we're working in a temporary object directory, the file is + * created with its final filename, otherwise it is created with + * a temporary name and renamed by finalize_object_file. + * If no rename is required, an empty string is returned in tmp. * * We want to avoid cross-directory filename renames, because those * can have problems on various filesystems (FAT, NFS, Coda). */ -static int create_tmpfile(struct strbuf *tmp, const char *filename) +static int create_objfile(const struct object_id *oid, struct strbuf *tmp, + struct strbuf *filename) { - int fd, dirlen = directory_size(filename); + int fd, dirlen, is_retrying = 0; + const char *object_name; + static const int object_mode = 0444; + loose_object_path(the_repository, filename, oid); + dirlen = directory_size(filename->buf); + +retry_create: strbuf_reset(tmp); - strbuf_add(tmp, filename, dirlen); - strbuf_addstr(tmp, "tmp_obj_XXXXXX"); - fd = git_mkstemp_mode(tmp->buf, 0444); - if (fd < 0 && dirlen && errno == ENOENT) { + if (!the_repository->objects->odb->is_temp) { + strbuf_add(tmp, filename->buf, dirlen); + object_name = "tmp_obj_XXXXXX"; + strbuf_addstr(tmp, object_name); + fd = git_mkstemp_mode(tmp->buf, object_mode); + } else { + fd = open(filename->buf, O_CREAT | O_EXCL | O_RDWR, object_mode); + } + + if (fd < 0 && dirlen && errno == ENOENT && !is_retrying) { /* * Make sure the directory exists; note that the contents * of the buffer are undefined after mkstemp returns an @@ -1926,15 +1947,15 @@ static int create_tmpfile(struct strbuf *tmp, const char *filename) * scratch. */ strbuf_reset(tmp); - strbuf_add(tmp, filename, dirlen - 1); + strbuf_add(tmp, filename->buf, dirlen - 1); if (mkdir(tmp->buf, 0777) && errno != EEXIST) return -1; if (adjust_shared_perm(tmp->buf)) return -1; /* Try again */ - strbuf_addstr(tmp, "/tmp_obj_XXXXXX"); - fd = git_mkstemp_mode(tmp->buf, 0444); + is_retrying = 1; + goto retry_create; } return fd; } @@ -1951,14 +1972,12 @@ static int write_loose_object(const struct object_id *oid, char *hdr, static struct strbuf tmp_file = STRBUF_INIT; static struct strbuf filename = STRBUF_INIT; - loose_object_path(the_repository, &filename, oid); - - fd = create_tmpfile(&tmp_file, filename.buf); + fd = create_objfile(oid, &tmp_file, &filename); if (fd < 0) { if (errno == EACCES) return error(_("insufficient permission for adding an object to repository database %s"), get_object_directory()); else - return error_errno(_("unable to create temporary file")); + return error_errno(_("unable to create object file")); } /* Set it up */ diff --git a/object-store.h b/object-store.h index c5130d8baea..551639f173d 100644 --- a/object-store.h +++ b/object-store.h @@ -27,6 +27,12 @@ struct object_directory { uint32_t loose_objects_subdir_seen[8]; /* 256 bits */ struct oidtree *loose_objects_cache; + /* + * This is a temporary object store, so there is no need to + * create new objects via rename. + */ + int is_temp; + /* * Path to the alternative object store. If this is a relative path, * it is relative to the current working directory. diff --git a/repository.c b/repository.c index 710a3b4bf87..75966153b75 100644 --- a/repository.c +++ b/repository.c @@ -80,6 +80,8 @@ void repo_set_gitdir(struct repository *repo, expand_base_dir(&repo->objects->odb->path, o->object_dir, repo->commondir, "objects"); + repo->objects->odb->is_temp = o->object_dir_is_temp; + free(repo->objects->alternate_db); repo->objects->alternate_db = xstrdup_or_null(o->alternate_db); expand_base_dir(&repo->graft_file, o->graft_file, diff --git a/repository.h b/repository.h index 3740c93bc0f..d3711367a6f 100644 --- a/repository.h +++ b/repository.h @@ -162,6 +162,7 @@ struct set_gitdir_args { const char *graft_file; const char *index_file; const char *alternate_db; + int object_dir_is_temp; }; void repo_set_gitdir(struct repository *repo, const char *root,