From patchwork Mon Dec 11 09:07:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Steinhardt X-Patchwork-Id: 13486864 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pks.im header.i=@pks.im header.b="EyUuc6S9"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="QcU0Tcjx" Received: from wout2-smtp.messagingengine.com (wout2-smtp.messagingengine.com [64.147.123.25]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F10ED9 for ; Mon, 11 Dec 2023 01:07:59 -0800 (PST) Received: from compute7.internal (compute7.nyi.internal [10.202.2.48]) by mailout.west.internal (Postfix) with ESMTP id 4A55432026C7; Mon, 11 Dec 2023 04:07:58 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute7.internal (MEProxy); Mon, 11 Dec 2023 04:07:58 -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=1702285677; x=1702372077; bh=d/ YwCty6KaZpaJE88FLpSCs/ki97O1H3EcjRPj3V1Is=; b=EyUuc6S95TXVom1QAC P52O4JXTikl8quxagK/EFPEfSV+ike94UXBcg9aU4+vwuwoz6ekRN1myQN6AMuVs 2wMfksFWVC0jle9pkXC25K1PKE2zFDMgmmlGSR/E5VsdKivHFXEqbExuLMhtnrrP dOqWCVnNS7Y0iYhGIl+C8IU9DfZpgvn6i5kB587bk8fXLfWb3Rc7m9Sawcp2yVJF kHKFanCH2NTOAdMMy5GYK2/qwXHA+PfqUkPvT2rM2VHl29/19wJgqjPXGqzFAFI6 MwLqX4wSoxT6jQbRxfSVnULM5dvP0W4PFulH5LVIICtMFofMlv6q7QFojYW86zX/ iFHg== 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=1702285677; x=1702372077; bh=d/YwCty6KaZpa JE88FLpSCs/ki97O1H3EcjRPj3V1Is=; b=QcU0TcjxPuv+74APDyydch3uit1c4 viJCnCirs+mJur62qn+YSsu9OEnjzKXY8m1O805XS11c9anK2CCvrr14UgsjqK0y HyhWt8nCBFMygHfeOkhzHCzCpHBqqx8ziVEk1MhP+gJZ9yMOw+UXTFnDLBZOKPV9 JxlG+feQXGWqlxs7AvdHiPcwIxcDkyd0smXtdXzqzbaxlJ0AAStbd0Rn2OgziMHm uBBFQE2VkBw8ql++LnGgGxy7ctQi7Pc1Afku/fM3EJEgZyurUrIU3tO1ECcoirD4 MM6IUOH/d03hKl2Q6f0wkEyZcV/qMu4J5S1S3bk/T5csFu+RyUasogz8g== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvkedrudeluddguddvlecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpeffhffvvefukfhfgggtuggjsehgtderredttddvnecuhfhrohhmpefrrght rhhitghkucfuthgvihhnhhgrrhguthcuoehpshesphhkshdrihhmqeenucggtffrrghtth gvrhhnpeeukedtvedtffevleejtefgheehieegkeeluddvfeefgeehgfeltddtheejleff teenucevlhhushhtvghrufhiiigvpedvnecurfgrrhgrmhepmhgrihhlfhhrohhmpehpsh esphhkshdrihhm X-ME-Proxy: Feedback-ID: i197146af:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 11 Dec 2023 04:07:56 -0500 (EST) Received: by vm-mail (OpenSMTPD) with ESMTPSA id 688e2e20 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Mon, 11 Dec 2023 09:06:20 +0000 (UTC) Date: Mon, 11 Dec 2023 10:07:54 +0100 From: Patrick Steinhardt To: git@vger.kernel.org Cc: Han-Wen Nienhuys , Jonathan Nieder , Taylor Blau , Eric Sunshine Subject: [PATCH v3 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..0c235724e2 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(add->lock_file->filename.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]); }