From patchwork Fri Dec 8 14:53:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Steinhardt X-Patchwork-Id: 13485481 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pks.im header.i=@pks.im header.b="SckDeTvG"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="1mP+V/22" Received: from wout5-smtp.messagingengine.com (wout5-smtp.messagingengine.com [64.147.123.21]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4ED621FF6 for ; Fri, 8 Dec 2023 06:53:31 -0800 (PST) Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailout.west.internal (Postfix) with ESMTP id E600B3200A02; Fri, 8 Dec 2023 09:53:25 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Fri, 08 Dec 2023 09:53:26 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pks.im; h=cc:cc :content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm1; t=1702047205; x=1702133605; bh=2o QjgDlEqnI3GqOz/Huo1YNbwyRyQBA3lZvTIdOsB/E=; b=SckDeTvG4zes/JdfSY FcyMpoV8RtZlmMmdYnlvXeqvgyeLmswN1goBEwCX+QzEZt+j9aeFbjog4MA7jKif ECXdt1OyIIdDnKB9OSy0duGybxweHEW3EIsapX4KZ3dRbWya/wAPnuzoImwYFTaV XvJyHa8npaUaaRe1hsdNu1FjIe4xksNgVWyZtk/sSHr3S8+H/BVYOCWTr4yWgoAh g3F5uqXPmwgnRitq4HPvCSk3XphtYumHnpws1bQJEarCmLrTlzSpbGyFKN2q0bUl ZC5GAfLZjkFck0rgaRGmuoJnNaiDXQhch8sEGoMD9Fv9FGHu6R7mfFup73LfGKz/ V8VA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; t=1702047205; x=1702133605; bh=2oQjgDlEqnI3G qOz/Huo1YNbwyRyQBA3lZvTIdOsB/E=; b=1mP+V/22V9I4QvJyQshPSxAWodwBi QdoHODykpV3k96G0yDwOy/5pBchKjG+/cDsa3z7DZQ96WRmqpHcNPkkp+0Sb/PE6 EesObAYZ/M1qNrLDTDG9rVnk/5LMJiaXgypqPVblkil613lGqO6+R8W/xnR+6zEv uszOPh8Q7CYGTiV2TXy42eyQsN37uQIyA3FHMJSTus1qhTMsxwzN8dSn6giBYhQn EI+OkkSmMTVRhllAiQEPD2OqsTuX/S9Lh+6lqa2Saev7RP8WBE/bO5IlqTEv2h0N ai3+yRTFL6/b95Baog2m1ZEcwkkjTvKiP0TFO14mTGzGVyG73JAMtLzuA== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvkedrudekiedgjeduucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvfevuffkfhggtggujgesghdtreertddtvdenucfhrhhomheprfgrthhr ihgtkhcuufhtvghinhhhrghrughtuceophhssehpkhhsrdhimheqnecuggftrfgrthhtvg hrnhepueektdevtdffveeljeetgfehheeigeekleduvdeffeeghefgledttdehjeelffet necuvehluhhsthgvrhfuihiivgepudenucfrrghrrghmpehmrghilhhfrhhomhepphhsse hpkhhsrdhimh X-ME-Proxy: Feedback-ID: i197146af:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 8 Dec 2023 09:53:24 -0500 (EST) Received: by vm-mail (OpenSMTPD) with ESMTPSA id 07a6a2da (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Fri, 8 Dec 2023 14:51:54 +0000 (UTC) Date: Fri, 8 Dec 2023 15:53:23 +0100 From: Patrick Steinhardt To: git@vger.kernel.org Cc: Han-Wen Nienhuys , Jonathan Nieder Subject: [PATCH v2 07/11] reftable/stack: fix stale lock when dying Message-ID: References: Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: When starting a transaction via `reftable_stack_init_addition()`, we create a lockfile for the reftable stack itself which we'll write the new list of tables to. But if we terminate abnormally e.g. via a call to `die()`, then we do not remove the lockfile. Subsequent executions of Git which try to modify references will thus fail with an out-of-date error. Fix this bug by registering the lock as a `struct tempfile`, which ensures automatic cleanup for us. Signed-off-by: Patrick Steinhardt --- reftable/stack.c | 47 +++++++++++++++-------------------------------- 1 file changed, 15 insertions(+), 32 deletions(-) diff --git a/reftable/stack.c b/reftable/stack.c index 2dd2373360..2f1494aef2 100644 --- a/reftable/stack.c +++ b/reftable/stack.c @@ -17,6 +17,8 @@ license that can be found in the LICENSE file or at #include "reftable-merged.h" #include "writer.h" +#include "tempfile.h" + static int stack_try_add(struct reftable_stack *st, int (*write_table)(struct reftable_writer *wr, void *arg), @@ -440,8 +442,7 @@ static void format_name(struct strbuf *dest, uint64_t min, uint64_t max) } struct reftable_addition { - int lock_file_fd; - struct strbuf lock_file_name; + struct tempfile *lock_file; struct reftable_stack *stack; char **new_tables; @@ -449,24 +450,19 @@ struct reftable_addition { uint64_t next_update_index; }; -#define REFTABLE_ADDITION_INIT \ - { \ - .lock_file_name = STRBUF_INIT \ - } +#define REFTABLE_ADDITION_INIT {0} static int reftable_stack_init_addition(struct reftable_addition *add, struct reftable_stack *st) { + struct strbuf lock_file_name = STRBUF_INIT; int err = 0; add->stack = st; - strbuf_reset(&add->lock_file_name); - strbuf_addstr(&add->lock_file_name, st->list_file); - strbuf_addstr(&add->lock_file_name, ".lock"); + strbuf_addf(&lock_file_name, "%s.lock", st->list_file); - add->lock_file_fd = open(add->lock_file_name.buf, - O_EXCL | O_CREAT | O_WRONLY, 0666); - if (add->lock_file_fd < 0) { + add->lock_file = create_tempfile(lock_file_name.buf); + if (!add->lock_file) { if (errno == EEXIST) { err = REFTABLE_LOCK_ERROR; } else { @@ -475,7 +471,7 @@ static int reftable_stack_init_addition(struct reftable_addition *add, goto done; } if (st->config.default_permissions) { - if (chmod(add->lock_file_name.buf, st->config.default_permissions) < 0) { + if (chmod(lock_file_name.buf, st->config.default_permissions) < 0) { err = REFTABLE_IO_ERROR; goto done; } @@ -495,6 +491,7 @@ static int reftable_stack_init_addition(struct reftable_addition *add, if (err) { reftable_addition_close(add); } + strbuf_release(&lock_file_name); return err; } @@ -512,15 +509,7 @@ static void reftable_addition_close(struct reftable_addition *add) add->new_tables = NULL; add->new_tables_len = 0; - if (add->lock_file_fd > 0) { - close(add->lock_file_fd); - add->lock_file_fd = 0; - } - if (add->lock_file_name.len > 0) { - unlink(add->lock_file_name.buf); - strbuf_release(&add->lock_file_name); - } - + delete_tempfile(&add->lock_file); strbuf_release(&nm); } @@ -536,8 +525,10 @@ void reftable_addition_destroy(struct reftable_addition *add) int reftable_addition_commit(struct reftable_addition *add) { struct strbuf table_list = STRBUF_INIT; + int lock_file_fd = get_tempfile_fd(add->lock_file); int i = 0; int err = 0; + if (add->new_tables_len == 0) goto done; @@ -550,28 +541,20 @@ int reftable_addition_commit(struct reftable_addition *add) strbuf_addstr(&table_list, "\n"); } - err = write_in_full(add->lock_file_fd, table_list.buf, table_list.len); + err = write_in_full(lock_file_fd, table_list.buf, table_list.len); strbuf_release(&table_list); if (err < 0) { err = REFTABLE_IO_ERROR; goto done; } - err = close(add->lock_file_fd); - add->lock_file_fd = 0; - if (err < 0) { - err = REFTABLE_IO_ERROR; - goto done; - } - - err = rename(add->lock_file_name.buf, add->stack->list_file); + err = rename_tempfile(&add->lock_file, add->stack->list_file); if (err < 0) { err = REFTABLE_IO_ERROR; goto done; } /* success, no more state to clean up. */ - strbuf_release(&add->lock_file_name); for (i = 0; i < add->new_tables_len; i++) { reftable_free(add->new_tables[i]); }