From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Turner Subject: [PATCH/RFC v2 3/3] refs: always handle non-normal refs in files backend Date: Wed, 6 Jan 2016 18:41:59 -0500 Message-ID: <1452123719-22634-3-git-send-email-dturner@twopensource.com> References: <567A5516.9070209@alum.mit.edu> <1452123719-22634-1-git-send-email-dturner@twopensource.com> Cc: David Turner To: git@vger.kernel.org, mhagger@alum.mit.edu X-From: git-owner@vger.kernel.org Thu Jan 07 00:42:43 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 1aGxix-0003G6-AH for gcvg-git-2@plane.gmane.org; Thu, 07 Jan 2016 00:42:39 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752653AbcAFXmd (ORCPT ); Wed, 6 Jan 2016 18:42:33 -0500 Received: from mail-qk0-f182.google.com ([209.85.220.182]:35531 "EHLO mail-qk0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752332AbcAFXm3 (ORCPT ); Wed, 6 Jan 2016 18:42:29 -0500 Received: by mail-qk0-f182.google.com with SMTP id n135so167966809qka.2 for ; Wed, 06 Jan 2016 15:42:29 -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=+QujK+uyam9GUnzrgsGcvuwjW1oZbSqu5QlkHCTAqKI=; b=0grlxBJkGSMFTxgqjng+kVwa5zdWMBCYppcuotJxqPXLESv1JGA2Y99tZ0vzX3gO2D ACcZCvpXX5bLs2rdyQSM3A94r57aQ1yuvs4h7MK8uwxi3D1e5BNrIdEmgDFZnO419C81 4VoElb6nqWqZRQVPnPwqe8ViVUjOVk77qOuqcOG+pC/d/WgBUUmKta4uOGkpFC+3wley alRPm5GZn0v1KVM9WFfofhgT8ikVJ4giOdf/BR/qDnnMGe0CwB9I2a2fY78ibVpSY8pp Fwk2T1Z6pWtkAQY/RwiFZpKeOGJAAF7alRSh6MzwR0iX4q9QAxJgXqnH1M8cZL8wUqJs SD5A== 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=+QujK+uyam9GUnzrgsGcvuwjW1oZbSqu5QlkHCTAqKI=; b=Ub1SQwOHiDX6AGes54XXSi4/2N31TBjwGAdEht7FtCB5ceoxdwCapR1hHxeRJbpR9U 6ShXfEh5+pgo5wyPM6yO9bpB/JIPLqKJGuunXp9L9l5lZEiI+GenTtjp4XaK74onjA8v HrvrG6h/yaC+ooMxS+UpMJInRZf2tU7yvXzLhHs+bE04/BhI9bp0oUiFH++Np8TBZZYu 3H9KysIXDUoi0pvUctLDfFZ95+pk+F9KrRBsRz7OXdmCcUD+RPis6fbp3tfuXR4EnM9b qg6jWWZfCQX9baSSxLnRDvTlVGS/AtA/jBOrwIEucruVYhG46I9ASxbDGtxniHIMJxy1 3FlA== X-Gm-Message-State: ALoCoQki1y/LxljCWpfFsdzddXckAB0xbcfAN8QVVAtbijFkGJ0TDA0qyPA9trAkvgodhPcrz/9twOMr6GDLCLujE8FBbgmNQw== X-Received: by 10.55.78.207 with SMTP id c198mr132172564qkb.34.1452123749023; Wed, 06 Jan 2016 15:42:29 -0800 (PST) Received: from ubuntu.twitter.biz ([192.133.79.145]) by smtp.gmail.com with ESMTPSA id f132sm27113524qhe.6.2016.01.06.15.42.27 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 06 Jan 2016 15:42:28 -0800 (PST) X-Mailer: git-send-email 2.4.2.749.g730654d-twtrsrc In-Reply-To: <1452123719-22634-1-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 | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++-- refs/refs-internal.h | 2 ++ 2 files changed, 82 insertions(+), 2 deletions(-) diff --git a/refs.c b/refs.c index 2496b91..67b0280 100644 --- a/refs.c +++ b/refs.c @@ -9,6 +9,11 @@ #include "object.h" #include "tag.h" +static const char split_transaction_fail_warning[] = + "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. */ @@ -781,6 +786,13 @@ 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) { @@ -788,8 +800,7 @@ 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; } @@ -1192,11 +1203,39 @@ static int dereference_symrefs(struct ref_transaction *transaction, return 0; } +/* + * 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; + + for (i = 0; i < transaction->nr; i++) { + int last; + struct ref_update *update = transaction->updates[i]; + + if (ref_type(update->refname) == REF_TYPE_NORMAL) + continue; + + last = --transaction->nr; + transaction->updates[i] = transaction->updates[last]; + files_transaction->updates[files_transaction->nr++] = update; + } + + return 0; +} + int ref_transaction_commit(struct ref_transaction *transaction, struct strbuf *err) { int ret = -1; struct string_list affected_refnames = STRING_LIST_INIT_NODUP; + struct string_list files_affected_refnames = STRING_LIST_INIT_NODUP; + struct string_list_item *item; + struct ref_transaction *files_transaction = NULL; assert(err); @@ -1212,6 +1251,26 @@ 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; @@ -1219,8 +1278,24 @@ int ref_transaction_commit(struct ref_transaction *transaction, ret = the_refs_backend->transaction_commit(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; } @@ -1276,6 +1351,9 @@ 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); } diff --git a/refs/refs-internal.h b/refs/refs-internal.h index 971f450..dd035f5 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -323,4 +323,6 @@ struct ref_storage_be { for_each_replace_ref_fn *for_each_replace_ref; }; +extern struct ref_storage_be refs_be_files; + #endif /* REFS_REFS_INTERNAL_H */ -- 2.4.2.749.g730654d-twtrsrc