From: Junio C Hamano <gitster@pobox.com>
To: Taylor Blau <me@ttaylorr.com>
Cc: git@vger.kernel.org, peff@peff.net
Subject: Re: [PATCH 3/3] builtin/repack.c: don't move existing packs out of the way
Date: Tue, 17 Nov 2020 13:28:53 -0800 [thread overview]
Message-ID: <xmqqzh3f4qqy.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <X7QvVB8GjI866a8z@nand.local> (Taylor Blau's message of "Tue, 17 Nov 2020 15:15:16 -0500")
Taylor Blau <me@ttaylorr.com> writes:
> That is, it is not the case that we pretend as if pack-objects didn't
> write files identical to ones that already exist, but rather that we
> respect what pack-objects wrote as the source of truth. That cuts two
> ways:
>
> - If pack-objects produced an identical pack to one that already
> exists with a bitmap, but did not produce a bitmap, we remove the
> bitmap that already exists. (This behavior is codified in t7700.14).
>
> - If pack-objects produced an identical pack to one that already
> exists, we trust the just-written version of the coresponding .idx,
> .promisor, and other files over the ones that already exist. This
> ensures that we use the most up-to-date versions of this files,
> which is safe even in the face of format changes in, say, the .idx
> file (which would not be reflected in the .idx file's name).
Very clearly written. I see no room for confusion, unlike the
original one.
Thanks, will replace.
>
> Helped-by: Jeff King <peff@peff.net>
> Signed-off-by: Taylor Blau <me@ttaylorr.com>
> ---
> builtin/repack.c | 103 +++++++----------------------------------------
> 1 file changed, 14 insertions(+), 89 deletions(-)
>
> diff --git a/builtin/repack.c b/builtin/repack.c
> index bb839180da..279be11a16 100644
> --- a/builtin/repack.c
> +++ b/builtin/repack.c
> @@ -306,7 +306,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
> struct string_list rollback = STRING_LIST_INIT_NODUP;
> struct string_list existing_packs = STRING_LIST_INIT_DUP;
> struct strbuf line = STRBUF_INIT;
> - int i, ext, ret, failed;
> + int i, ext, ret;
> FILE *out;
>
> /* variables to be filled by option parsing */
> @@ -463,109 +463,34 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
>
> /*
> * Ok we have prepared all new packfiles.
> - * First see if there are packs of the same name and if so
> - * if we can move them out of the way (this can happen if we
> - * repacked immediately after packing fully.
> */
> - failed = 0;
> for_each_string_list_item(item, &names) {
> for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
> char *fname, *fname_old;
>
> - fname = mkpathdup("%s/pack-%s%s", packdir,
> - item->string, exts[ext].name);
> - if (!file_exists(fname)) {
> - free(fname);
> - continue;
> - }
> -
> - fname_old = mkpathdup("%s/old-%s%s", packdir,
> - item->string, exts[ext].name);
> - if (file_exists(fname_old))
> - if (unlink(fname_old))
> - failed = 1;
> -
> - if (!failed && rename(fname, fname_old)) {
> - free(fname);
> - free(fname_old);
> - failed = 1;
> - break;
> - } else {
> - string_list_append(&rollback, fname);
> - free(fname_old);
> - }
> - }
> - if (failed)
> - break;
> - }
> - if (failed) {
> - struct string_list rollback_failure = STRING_LIST_INIT_DUP;
> - for_each_string_list_item(item, &rollback) {
> - char *fname, *fname_old;
> - fname = mkpathdup("%s/%s", packdir, item->string);
> - fname_old = mkpathdup("%s/old-%s", packdir, item->string);
> - if (rename(fname_old, fname))
> - string_list_append(&rollback_failure, fname);
> - free(fname);
> - free(fname_old);
> - }
> -
> - if (rollback_failure.nr) {
> - int i;
> - fprintf(stderr,
> - _("WARNING: Some packs in use have been renamed by\n"
> - "WARNING: prefixing old- to their name, in order to\n"
> - "WARNING: replace them with the new version of the\n"
> - "WARNING: file. But the operation failed, and the\n"
> - "WARNING: attempt to rename them back to their\n"
> - "WARNING: original names also failed.\n"
> - "WARNING: Please rename them in %s manually:\n"), packdir);
> - for (i = 0; i < rollback_failure.nr; i++)
> - fprintf(stderr, "WARNING: old-%s -> %s\n",
> - rollback_failure.items[i].string,
> - rollback_failure.items[i].string);
> - }
> - exit(1);
> - }
> -
> - /* Now the ones with the same name are out of the way... */
> - for_each_string_list_item(item, &names) {
> - for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
> - char *fname, *fname_old;
> - struct stat statbuffer;
> - int exists = 0;
> fname = mkpathdup("%s/pack-%s%s",
> packdir, item->string, exts[ext].name);
> fname_old = mkpathdup("%s-%s%s",
> packtmp, item->string, exts[ext].name);
> - if (!stat(fname_old, &statbuffer)) {
> - statbuffer.st_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
> - chmod(fname_old, statbuffer.st_mode);
> - exists = 1;
> - }
> - if (exists || !exts[ext].optional) {
> +
> + if (((uintptr_t)item->util) & (1 << ext)) {
> + struct stat statbuffer;
> + if (!stat(fname_old, &statbuffer)) {
> + statbuffer.st_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
> + chmod(fname_old, statbuffer.st_mode);
> + }
> +
> if (rename(fname_old, fname))
> die_errno(_("renaming '%s' failed"), fname_old);
> - }
> + } else if (!exts[ext].optional)
> + die(_("missing required file: %s"), fname_old);
> + else if (unlink(fname) < 0 && errno != ENOENT)
> + die_errno(_("could not unlink: %s"), fname);
> +
> free(fname);
> free(fname_old);
> }
> }
> -
> - /* Remove the "old-" files */
> - for_each_string_list_item(item, &names) {
> - for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
> - char *fname;
> - fname = mkpathdup("%s/old-%s%s",
> - packdir,
> - item->string,
> - exts[ext].name);
> - if (remove_path(fname))
> - warning(_("failed to remove '%s'"), fname);
> - free(fname);
> - }
> - }
> -
> /* End of pack replacement. */
>
> reprepare_packed_git(the_repository);
> --
> 2.29.2.312.gabc4d358d8
prev parent reply other threads:[~2020-11-17 21:29 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-16 18:41 [PATCH 0/3] repack: don't move existing packs out of the way Taylor Blau
2020-11-16 18:41 ` [PATCH 1/3] repack: make "exts" array available outside cmd_repack() Taylor Blau
2020-11-16 18:41 ` [PATCH 2/3] builtin/repack.c: keep track of what pack-objects wrote Taylor Blau
2020-11-16 18:41 ` [PATCH 3/3] builtin/repack.c: don't move existing packs out of the way Taylor Blau
2020-11-16 23:29 ` Junio C Hamano
2020-11-17 0:02 ` Jeff King
2020-11-17 0:26 ` Taylor Blau
2020-11-17 0:25 ` Taylor Blau
2020-11-17 0:46 ` Junio C Hamano
2020-11-17 20:15 ` Taylor Blau
2020-11-17 21:28 ` Junio C Hamano [this message]
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