From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C12DC48BE5 for ; Thu, 10 Jun 2021 12:59:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAD7F613C9 for ; Thu, 10 Jun 2021 12:59:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230416AbhFJNBD (ORCPT ); Thu, 10 Jun 2021 09:01:03 -0400 Received: from mail-wr1-f41.google.com ([209.85.221.41]:39847 "EHLO mail-wr1-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230376AbhFJNBC (ORCPT ); Thu, 10 Jun 2021 09:01:02 -0400 Received: by mail-wr1-f41.google.com with SMTP id l2so2212989wrw.6 for ; Thu, 10 Jun 2021 05:58:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=uf+y4ZrMvh9HtGQoVOmGu6w9gtBwi2AXbIFRiB9KD5s=; b=UbuC92NHTcGYU9C0yQOWn22P2xNPmb2YVphPJ8CBiNTV1g2vsfyOeyXvvWb2PUqd+s 2a2XSw+Cw3vjmtx+/M2jIPcHrJGN63c4LN73x4dq/b8UHL9ixa3Etc7EcOb60OjeHxsJ oxgF09DVtBF0MDC2PSIEcUDtIr6iWIzdBXkwv5UzTVSL0QD2wrvSb24XLh8y4s1lWLkD oeoqOlS/JnTKoiB6Y+JYNT+5YQXs6IJjzrsJUGkIZvmGfhMAXyYS2kApjCBcTUEBbnFy ngvBNAp1I00c7P4JA8HGXq7MERpVhmCfRx0HN07vD4kJQCl8OEgHNgBgNtb+ywqMlCkx phUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=uf+y4ZrMvh9HtGQoVOmGu6w9gtBwi2AXbIFRiB9KD5s=; b=pnlWWTRIrdjJe+ijrr2L0rwLX/YpnoxcOuCCmxHXS9cRP7+43ScpLYKhzSdrHE3Xrp EOaPyYN+2PHXqtvedi0Aa1TWV9kfoYGtt7DXrtwFW8lo6oL8MXLkFk+bjJmRjx5+g1p/ gJsu1+5JiXqA+YsI6VcZRCA9sk1Mgr9AHrpRC8gsILzcgZRQn+PVNC+FiLsH9c4G4EJD mjsXbH9YBe/DXVSJLtBBLH6ciQ7Tkt4dUKRQWFXJG1Hmvs6A49KPaV3L8gby8BMcg8dz baM7cIG7fMwq5xt5uh+mpqyembxXZ3MIGaCwCCEAejkHZZU/VRdlXtVUJrvXKIs/4qEh VoYw== X-Gm-Message-State: AOAM5333HJrJG6LCjhXiqBmsH1WUZRM0u9R2L5g+gqSOKOsLbROfFpix FPykCHH+8OwOlGU7JE+swSg3vpiLi5s= X-Google-Smtp-Source: ABdhPJxC7K32JHmdCOoyWrzxUNF5RhieqU3xNB0f3sAChRkDNbhVhQuLqoM4l30ErTuTVNRUlOXh7Q== X-Received: by 2002:a5d:64a4:: with SMTP id m4mr5162611wrp.185.1623329872187; Thu, 10 Jun 2021 05:57:52 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id n6sm1463068wme.21.2021.06.10.05.57.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Jun 2021 05:57:51 -0700 (PDT) Message-Id: <3e2831e59c8e4cb8aef416a41b55083887b4559c.1623329869.git.gitgitgadget@gmail.com> In-Reply-To: References: From: "Han-Wen Nienhuys via GitGitGadget" Date: Thu, 10 Jun 2021 12:57:43 +0000 Subject: [PATCH v2 3/8] refs: make errno output explicit for read_raw_ref_fn Fcc: Sent Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 To: git@vger.kernel.org Cc: Han-Wen Nienhuys , Jonathan Tan , Han-Wen Nienhuys , Han-Wen Nienhuys Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Han-Wen Nienhuys read_raw_ref_fn needs to supply a credible errno for a number of cases. These are primarily: 1) The files backend calls read_raw_ref from lock_raw_ref, and uses the resulting error codes to create/remove directories as needed. 2) ENOENT should be translated in a zero OID, optionally with REF_ISBROKEN set, returning the last successfully resolved symref. This is necessary so read_raw_ref("HEAD") on an empty repo returns refs/heads/main (or the default branch du-jour), and we know on which branch to create the first commit. Make this information flow explicit by adding a failure_errno to the signature of read_raw_ref. All errnos from the files backend are still propagated unchanged, even though inspection suggests only ENOTDIR, EISDIR and ENOENT are relevant. Signed-off-by: Han-Wen Nienhuys Reviewed-by: Jonathan Tan --- refs.c | 8 ++++++-- refs/debug.c | 4 ++-- refs/files-backend.c | 24 ++++++++++++------------ refs/packed-backend.c | 8 ++++---- refs/refs-internal.h | 17 +++++++++-------- 5 files changed, 33 insertions(+), 28 deletions(-) diff --git a/refs.c b/refs.c index 8c9490235ea6..bebe3f584da7 100644 --- a/refs.c +++ b/refs.c @@ -1675,13 +1675,17 @@ int refs_read_raw_ref(struct ref_store *ref_store, const char *refname, struct object_id *oid, struct strbuf *referent, unsigned int *type) { + int result, failure; if (!strcmp(refname, "FETCH_HEAD") || !strcmp(refname, "MERGE_HEAD")) { return refs_read_special_head(ref_store, refname, oid, referent, type); } - return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, - type); + failure = 0; + result = ref_store->be->read_raw_ref(ref_store, refname, oid, referent, + type, &failure); + errno = failure; + return result; } /* This function needs to return a meaningful errno on failure */ diff --git a/refs/debug.c b/refs/debug.c index 7db4abccc341..f12413a9bc0f 100644 --- a/refs/debug.c +++ b/refs/debug.c @@ -238,7 +238,7 @@ debug_ref_iterator_begin(struct ref_store *ref_store, const char *prefix, static int debug_read_raw_ref(struct ref_store *ref_store, const char *refname, struct object_id *oid, struct strbuf *referent, - unsigned int *type) + unsigned int *type, int *failure_errno) { struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; int res = 0; @@ -246,7 +246,7 @@ static int debug_read_raw_ref(struct ref_store *ref_store, const char *refname, oidcpy(oid, null_oid()); errno = 0; res = drefs->refs->be->read_raw_ref(drefs->refs, refname, oid, referent, - type); + type, failure_errno); if (res == 0) { trace_printf_key(&trace_refs, "read_raw_ref: %s: %s (=> %s) type %x: %d\n", diff --git a/refs/files-backend.c b/refs/files-backend.c index 6aa0f5c41dd3..8f969c8f711f 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -341,9 +341,9 @@ static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs) return refs->loose; } -static int files_read_raw_ref(struct ref_store *ref_store, - const char *refname, struct object_id *oid, - struct strbuf *referent, unsigned int *type) +static int files_read_raw_ref(struct ref_store *ref_store, const char *refname, + struct object_id *oid, struct strbuf *referent, + unsigned int *type, int *failure_errno) { struct files_ref_store *refs = files_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); @@ -354,7 +354,6 @@ static int files_read_raw_ref(struct ref_store *ref_store, struct stat st; int fd; int ret = -1; - int save_errno; int remaining_retries = 3; *type = 0; @@ -459,10 +458,10 @@ static int files_read_raw_ref(struct ref_store *ref_store, ret = parse_loose_ref_contents(buf, oid, referent, type); out: - save_errno = errno; + if (failure_errno) + *failure_errno = errno; strbuf_release(&sb_path); strbuf_release(&sb_contents); - errno = save_errno; return ret; } @@ -541,6 +540,7 @@ static int lock_raw_ref(struct files_ref_store *refs, struct strbuf ref_file = STRBUF_INIT; int attempts_remaining = 3; int ret = TRANSACTION_GENERIC_ERROR; + int failure_errno = 0; assert(err); files_assert_main_repository(refs, "lock_raw_ref"); @@ -629,9 +629,9 @@ static int lock_raw_ref(struct files_ref_store *refs, * fear that its value will change. */ - if (files_read_raw_ref(&refs->base, refname, - &lock->old_oid, referent, type)) { - if (errno == ENOENT) { + if (files_read_raw_ref(&refs->base, refname, &lock->old_oid, referent, + type, &failure_errno)) { + if (failure_errno == ENOENT) { if (mustexist) { /* Garden variety missing reference. */ strbuf_addf(err, "unable to resolve reference '%s'", @@ -655,7 +655,7 @@ static int lock_raw_ref(struct files_ref_store *refs, * reference named "refs/foo/bar/baz". */ } - } else if (errno == EISDIR) { + } else if (failure_errno == EISDIR) { /* * There is a directory in the way. It might have * contained references that have been deleted. If @@ -693,13 +693,13 @@ static int lock_raw_ref(struct files_ref_store *refs, goto error_return; } } - } else if (errno == EINVAL && (*type & REF_ISBROKEN)) { + } else if (failure_errno == EINVAL && (*type & REF_ISBROKEN)) { strbuf_addf(err, "unable to resolve reference '%s': " "reference broken", refname); goto error_return; } else { strbuf_addf(err, "unable to resolve reference '%s': %s", - refname, strerror(errno)); + refname, strerror(failure_errno)); goto error_return; } diff --git a/refs/packed-backend.c b/refs/packed-backend.c index dfecdbc1db60..a457f18e93c8 100644 --- a/refs/packed-backend.c +++ b/refs/packed-backend.c @@ -724,9 +724,9 @@ static struct snapshot *get_snapshot(struct packed_ref_store *refs) return refs->snapshot; } -static int packed_read_raw_ref(struct ref_store *ref_store, - const char *refname, struct object_id *oid, - struct strbuf *referent, unsigned int *type) +static int packed_read_raw_ref(struct ref_store *ref_store, const char *refname, + struct object_id *oid, struct strbuf *referent, + unsigned int *type, int *failure_errno) { struct packed_ref_store *refs = packed_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); @@ -739,7 +739,7 @@ static int packed_read_raw_ref(struct ref_store *ref_store, if (!rec) { /* refname is not a packed reference. */ - errno = ENOENT; + *failure_errno = ENOENT; return -1; } diff --git a/refs/refs-internal.h b/refs/refs-internal.h index f4445e329045..904b2a9e51ae 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -617,11 +617,12 @@ typedef int reflog_expire_fn(struct ref_store *ref_store, * properly-formatted or even safe reference name. NEITHER INPUT NOR * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION. * - * Return 0 on success. If the ref doesn't exist, set errno to ENOENT - * and return -1. If the ref exists but is neither a symbolic ref nor - * an object ID, it is broken; set REF_ISBROKEN in type, and return -1 - * (errno should not be ENOENT) If there is another error reading the - * ref, set errno appropriately and return -1. + * Return 0 on success. If the ref doesn't exist, set failure_errno to ENOENT + * and return -1. If the ref exists but is neither a symbolic ref nor an object + * ID, it is broken; set REF_ISBROKEN in type, and return -1 (failure_errno + * should not be ENOENT). The files backend may return EISDIR (if the ref name + * is a directory) and ENOTDIR (if a ref prefix is not a directory). If there is + * another error reading the ref, set failure_errno appropriately and return -1. * * Backend-specific flags might be set in type as well, regardless of * outcome. @@ -635,9 +636,9 @@ typedef int reflog_expire_fn(struct ref_store *ref_store, * - in all other cases, referent will be untouched, and therefore * refname will still be valid and unchanged. */ -typedef int read_raw_ref_fn(struct ref_store *ref_store, - const char *refname, struct object_id *oid, - struct strbuf *referent, unsigned int *type); +typedef int read_raw_ref_fn(struct ref_store *ref_store, const char *refname, + struct object_id *oid, struct strbuf *referent, + unsigned int *type, int *failure_errno); struct ref_storage_be { struct ref_storage_be *next; -- gitgitgadget