From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Turner Subject: [PATCH v2 14/21] refs: always handle non-normal refs in files backend Date: Mon, 11 Jan 2016 20:22:13 -0500 Message-ID: <1452561740-8668-15-git-send-email-dturner@twopensource.com> References: <1452561740-8668-1-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 Tue Jan 12 02:22:58 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 1aInfk-0003L8-5j for gcvg-git-2@plane.gmane.org; Tue, 12 Jan 2016 02:22:56 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761876AbcALBWu (ORCPT ); Mon, 11 Jan 2016 20:22:50 -0500 Received: from mail-qk0-f172.google.com ([209.85.220.172]:35835 "EHLO mail-qk0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761817AbcALBWs (ORCPT ); Mon, 11 Jan 2016 20:22:48 -0500 Received: by mail-qk0-f172.google.com with SMTP id n135so233503238qka.2 for ; Mon, 11 Jan 2016 17:22:47 -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=SXjM7bNH3ZrMApO34PV2iIbnsKSzSwTjjhFVPLlJoDM=; b=XxuOBMgbsBsZsz/EKs8IFdxbDm36WXD+yJeddhEt/O1CqN8BhEBs8net6OlQ52awVj WyPXPTJX7WCL/Pi5dQLQjWcwqPxaYC0gB7W7tYtpopGzqeR1pzzIvAaTO4IjcLS0SGEl gIPBAyTXiXR0Tnb8xv8y9bmhW/PtYL1L6yGZ9LzLWVan7m0FBzqPmPWE/saywrUVN46X oCENv7rf0/2og6c9nP0BXdgCZJNDbQ2kyuKqtZvjqeahnmhxYWdXcJ1pLqvILrEwHZzA g6P3WT8aPXrULclCMAb8O8hSdZKz5EOeHVFrPhz4cbWugKVdt3RMXOU/cOjeAygyr5Gt H/lg== 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=SXjM7bNH3ZrMApO34PV2iIbnsKSzSwTjjhFVPLlJoDM=; b=H38fOCoEz2xM0fPBvs1ZGdbbSOJ1ovjaq8Irm5EaDE5sqCRhLDX+NldNGSaVWswxu1 1FcQbFjAtJmzXWHUD/9QGDwlNtEIrKJ9HAAEIXWGTtJ20psfbh2G9HFZtM08JnCmpJL1 kyXdyIM28vpH+j3pMmJ5NCVh+nmJejPl0DV1taLaA3eF/WFK/SzhoB6jaBELZCRdxrY/ Qe2cKK9CIL3+2Rxs1f0wFNQ1zuC6HmPTSjQrSP8H0a1vfVBh98cBCZ1kH3vsgYoD7h77 5M8Sg6Z6ZUUWUMuwwiBVrbC8l9F11QU0hHHWzIyr+xiGwJ1AiNKgKinZ4INI9x3XQYPy Ljvg== X-Gm-Message-State: ALoCoQnLZdQMxZgJtgKyXWXNAIY59koTKhkEcR8IYguz6E1jMf6RZH1Q5ijKjw69VOq9yEDkH/429XRcQ9eMQFp1eLurhq+MbA== X-Received: by 10.55.73.69 with SMTP id w66mr165799337qka.39.1452561767476; Mon, 11 Jan 2016 17:22:47 -0800 (PST) Received: from ubuntu.twitter.corp? ([8.25.196.26]) by smtp.gmail.com with ESMTPSA id d64sm55362053qgd.48.2016.01.11.17.22.46 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 11 Jan 2016 17:22:46 -0800 (PST) X-Mailer: git-send-email 2.4.2.749.g730654d-twtrsrc In-Reply-To: <1452561740-8668-1-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 1b17c15..d035feb 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. */ @@ -780,6 +785,13 @@ 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) { @@ -787,8 +799,7 @@ 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]; + add_update_obj(files_transaction, 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 75d4dae..72c64e8 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -321,4 +321,6 @@ 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