f57a739691
Opening multiple instance of the same MIDX can lead to problems like two
separate packed_git structures which represent the same pack being added
to the repository's object store.
The above scenario can happen because prepare_midx_pack() checks if
`m->packs[pack_int_id]` is NULL in order to determine if a pack has been
opened and installed in the repository before. But a caller can
construct two copies of the same MIDX by calling get_multi_pack_index()
and load_multi_pack_index() since the former manipulates the
object store directly but the latter is a lower-level routine which
allocates a new MIDX for each call.
So if prepare_midx_pack() is called on multiple MIDXs with the same
pack_int_id, then that pack will be installed twice in the object
store's packed_git pointer.
This can lead to problems in, for e.g., the pack-bitmap code, which does
something like the following (in pack-bitmap.c:open_pack_bitmap()):
struct bitmap_index *bitmap_git = ...;
for (p = get_all_packs(r); p; p = p->next) {
if (open_pack_bitmap_1(bitmap_git, p) == 0)
ret = 0;
}
which is a problem if two copies of the same pack exist in the
packed_git list because pack-bitmap.c:open_pack_bitmap_1() contains a
conditional like the following:
if (bitmap_git->pack || bitmap_git->midx) {
/* ignore extra bitmap file; we can only handle one */
warning("ignoring extra bitmap file: %s", packfile->pack_name);
close(fd);
return -1;
}
Avoid this scenario by not letting write_midx_internal() open a MIDX
that isn't also pointed at by the object store. So long as this is the
case, other routines should prefer to open MIDXs with
get_multi_pack_index() or reprepare_packed_git() instead of creating
instances on their own. Because get_multi_pack_index() returns
`r->object_store->multi_pack_index` if it is non-NULL, we'll only have
one instance of a MIDX open at one time, avoiding these problems.
To encourage this, drop the `struct multi_pack_index *` parameter from
`write_midx_internal()`, and rely instead on the `object_dir` to find
(or initialize) the correct MIDX instance.
Likewise, replace the call to `close_midx()` with
`close_object_store()`, since we're about to replace the MIDX with a new
one and should invalidate the object store's memory of any MIDX that
might have existed beforehand.
Note that this now forbids passing object directories that don't belong
to alternate repositories over `--object-dir`, since before we would
have happily opened a MIDX in any directory, but now restrict ourselves
to only those reachable by `r->objects->multi_pack_index` (and alternate
MIDXs that we can see by walking the `next` pointer).
As far as I can tell, supporting arbitrary directories with
`--object-dir` was a historical accident, since even the documentation
says `<alt>` when referring to the value passed to this option.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
|
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| .github | ||
| Documentation | ||
| block-sha1 | ||
| builtin | ||
| ci | ||
| compat | ||
| contrib | ||
| ewah | ||
| git-gui | ||
| gitk-git | ||
| gitweb | ||
| mergetools | ||
| negotiator | ||
| perl | ||
| po | ||
| ppc | ||
| refs | ||
| sha1collisiondetection@855827c583 | ||
| sha1dc | ||
| sha256 | ||
| t | ||
| templates | ||
| trace2 | ||
| xdiff | ||
| .cirrus.yml | ||
| .clang-format | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| .gitmodules | ||
| .mailmap | ||
| .travis.yml | ||
| .tsan-suppressions | ||
| CODE_OF_CONDUCT.md | ||
| COPYING | ||
| GIT-VERSION-GEN | ||
| INSTALL | ||
| LGPL-2.1 | ||
| Makefile | ||
| README.md | ||
| RelNotes | ||
| SECURITY.md | ||
| abspath.c | ||
| aclocal.m4 | ||
| add-interactive.c | ||
| add-interactive.h | ||
| add-patch.c | ||
| advice.c | ||
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| alias.c | ||
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| alloc.c | ||
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| apply.c | ||
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| archive-tar.c | ||
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| attr.c | ||
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| banned.h | ||
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| bisect.c | ||
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| blame.c | ||
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| blob.c | ||
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| bloom.c | ||
| bloom.h | ||
| branch.c | ||
| branch.h | ||
| builtin.h | ||
| bulk-checkin.c | ||
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| bundle.c | ||
| bundle.h | ||
| cache-tree.c | ||
| cache-tree.h | ||
| cache.h | ||
| cbtree.c | ||
| cbtree.h | ||
| chdir-notify.c | ||
| chdir-notify.h | ||
| check-builtins.sh | ||
| check_bindir | ||
| checkout.c | ||
| checkout.h | ||
| chunk-format.c | ||
| chunk-format.h | ||
| color.c | ||
| color.h | ||
| column.c | ||
| column.h | ||
| combine-diff.c | ||
| command-list.txt | ||
| commit-graph.c | ||
| commit-graph.h | ||
| commit-reach.c | ||
| commit-reach.h | ||
| commit-slab-decl.h | ||
| commit-slab-impl.h | ||
| commit-slab.h | ||
| commit.c | ||
| commit.h | ||
| common-main.c | ||
| config.c | ||
| config.h | ||
| config.mak.dev | ||
| config.mak.in | ||
| config.mak.uname | ||
| configure.ac | ||
| connect.c | ||
| connect.h | ||
| connected.c | ||
| connected.h | ||
| convert.c | ||
| convert.h | ||
| copy.c | ||
| credential.c | ||
| credential.h | ||
| csum-file.c | ||
| csum-file.h | ||
| ctype.c | ||
| daemon.c | ||
| date.c | ||
| decorate.c | ||
| decorate.h | ||
| delta-islands.c | ||
| delta-islands.h | ||
| delta.h | ||
| detect-compiler | ||
| diff-delta.c | ||
| diff-lib.c | ||
| diff-merges.c | ||
| diff-merges.h | ||
| diff-no-index.c | ||
| diff.c | ||
| diff.h | ||
| diffcore-break.c | ||
| diffcore-delta.c | ||
| diffcore-order.c | ||
| diffcore-pickaxe.c | ||
| diffcore-rename.c | ||
| diffcore-rotate.c | ||
| diffcore.h | ||
| dir-iterator.c | ||
| dir-iterator.h | ||
| dir.c | ||
| dir.h | ||
| editor.c | ||
| entry.c | ||
| entry.h | ||
| environment.c | ||
| environment.h | ||
| exec-cmd.c | ||
| exec-cmd.h | ||
| fetch-negotiator.c | ||
| fetch-negotiator.h | ||
| fetch-pack.c | ||
| fetch-pack.h | ||
| fmt-merge-msg.c | ||
| fmt-merge-msg.h | ||
| fsck.c | ||
| fsck.h | ||
| fsmonitor.c | ||
| fsmonitor.h | ||
| fuzz-commit-graph.c | ||
| fuzz-pack-headers.c | ||
| fuzz-pack-idx.c | ||
| generate-cmdlist.sh | ||
| generate-configlist.sh | ||
| gettext.c | ||
| gettext.h | ||
| git-add--interactive.perl | ||
| git-archimport.perl | ||
| git-bisect.sh | ||
| git-compat-util.h | ||
| git-cvsexportcommit.perl | ||
| git-cvsimport.perl | ||
| git-cvsserver.perl | ||
| git-difftool--helper.sh | ||
| git-filter-branch.sh | ||
| git-instaweb.sh | ||
| git-merge-octopus.sh | ||
| git-merge-one-file.sh | ||
| git-merge-resolve.sh | ||
| git-mergetool--lib.sh | ||
| git-mergetool.sh | ||
| git-p4.py | ||
| git-quiltimport.sh | ||
| git-rebase--preserve-merges.sh | ||
| git-request-pull.sh | ||
| git-send-email.perl | ||
| git-sh-i18n.sh | ||
| git-sh-setup.sh | ||
| git-submodule.sh | ||
| git-svn.perl | ||
| git-web--browse.sh | ||
| git.c | ||
| git.rc | ||
| gpg-interface.c | ||
| gpg-interface.h | ||
| graph.c | ||
| graph.h | ||
| grep.c | ||
| grep.h | ||
| hash-lookup.c | ||
| hash-lookup.h | ||
| hash.h | ||
| hashmap.c | ||
| hashmap.h | ||
| help.c | ||
| help.h | ||
| hex.c | ||
| http-backend.c | ||
| http-fetch.c | ||
| http-push.c | ||
| http-walker.c | ||
| http.c | ||
| http.h | ||
| ident.c | ||
| imap-send.c | ||
| iterator.h | ||
| json-writer.c | ||
| json-writer.h | ||
| khash.h | ||
| kwset.c | ||
| kwset.h | ||
| levenshtein.c | ||
| levenshtein.h | ||
| line-log.c | ||
| line-log.h | ||
| line-range.c | ||
| line-range.h | ||
| linear-assignment.c | ||
| linear-assignment.h | ||
| list-objects-filter-options.c | ||
| list-objects-filter-options.h | ||
| list-objects-filter.c | ||
| list-objects-filter.h | ||
| list-objects.c | ||
| list-objects.h | ||
| list.h | ||
| ll-merge.c | ||
| ll-merge.h | ||
| lockfile.c | ||
| lockfile.h | ||
| log-tree.c | ||
| log-tree.h | ||
| ls-refs.c | ||
| ls-refs.h | ||
| mailinfo.c | ||
| mailinfo.h | ||
| mailmap.c | ||
| mailmap.h | ||
| match-trees.c | ||
| mem-pool.c | ||
| mem-pool.h | ||
| merge-blobs.c | ||
| merge-blobs.h | ||
| merge-ort-wrappers.c | ||
| merge-ort-wrappers.h | ||
| merge-ort.c | ||
| merge-ort.h | ||
| merge-recursive.c | ||
| merge-recursive.h | ||
| merge.c | ||
| mergesort.c | ||
| mergesort.h | ||
| midx.c | ||
| midx.h | ||
| name-hash.c | ||
| notes-cache.c | ||
| notes-cache.h | ||
| notes-merge.c | ||
| notes-merge.h | ||
| notes-utils.c | ||
| notes-utils.h | ||
| notes.c | ||
| notes.h | ||
| object-file.c | ||
| object-name.c | ||
| object-store.h | ||
| object.c | ||
| object.h | ||
| oid-array.c | ||
| oid-array.h | ||
| oidmap.c | ||
| oidmap.h | ||
| oidset.c | ||
| oidset.h | ||
| oidtree.c | ||
| oidtree.h | ||
| pack-bitmap-write.c | ||
| pack-bitmap.c | ||
| pack-bitmap.h | ||
| pack-check.c | ||
| pack-objects.c | ||
| pack-objects.h | ||
| pack-revindex.c | ||
| pack-revindex.h | ||
| pack-write.c | ||
| pack.h | ||
| packfile.c | ||
| packfile.h | ||
| pager.c | ||
| parallel-checkout.c | ||
| parallel-checkout.h | ||
| parse-options-cb.c | ||
| parse-options.c | ||
| parse-options.h | ||
| patch-delta.c | ||
| patch-ids.c | ||
| patch-ids.h | ||
| path.c | ||
| path.h | ||
| pathspec.c | ||
| pathspec.h | ||
| pkt-line.c | ||
| pkt-line.h | ||
| preload-index.c | ||
| pretty.c | ||
| pretty.h | ||
| prio-queue.c | ||
| prio-queue.h | ||
| progress.c | ||
| progress.h | ||
| promisor-remote.c | ||
| promisor-remote.h | ||
| prompt.c | ||
| prompt.h | ||
| protocol-caps.c | ||
| protocol-caps.h | ||
| protocol.c | ||
| protocol.h | ||
| prune-packed.c | ||
| prune-packed.h | ||
| quote.c | ||
| quote.h | ||
| range-diff.c | ||
| range-diff.h | ||
| reachable.c | ||
| reachable.h | ||
| read-cache.c | ||
| rebase-interactive.c | ||
| rebase-interactive.h | ||
| rebase.c | ||
| rebase.h | ||
| ref-filter.c | ||
| ref-filter.h | ||
| reflog-walk.c | ||
| reflog-walk.h | ||
| refs.c | ||
| refs.h | ||
| refspec.c | ||
| refspec.h | ||
| remote-curl.c | ||
| remote.c | ||
| remote.h | ||
| replace-object.c | ||
| replace-object.h | ||
| repo-settings.c | ||
| repository.c | ||
| repository.h | ||
| rerere.c | ||
| rerere.h | ||
| reset.c | ||
| reset.h | ||
| resolve-undo.c | ||
| resolve-undo.h | ||
| revision.c | ||
| revision.h | ||
| run-command.c | ||
| run-command.h | ||
| send-pack.c | ||
| send-pack.h | ||
| sequencer.c | ||
| sequencer.h | ||
| serve.c | ||
| serve.h | ||
| server-info.c | ||
| setup.c | ||
| sh-i18n--envsubst.c | ||
| sha1dc_git.c | ||
| sha1dc_git.h | ||
| shallow.c | ||
| shallow.h | ||
| shell.c | ||
| shortlog.h | ||
| sideband.c | ||
| sideband.h | ||
| sigchain.c | ||
| sigchain.h | ||
| simple-ipc.h | ||
| sparse-index.c | ||
| sparse-index.h | ||
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| strbuf.c | ||
| strbuf.h | ||
| streaming.c | ||
| streaming.h | ||
| string-list.c | ||
| string-list.h | ||
| strmap.c | ||
| strmap.h | ||
| strvec.c | ||
| strvec.h | ||
| sub-process.c | ||
| sub-process.h | ||
| submodule-config.c | ||
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| submodule.c | ||
| submodule.h | ||
| symlinks.c | ||
| tag.c | ||
| tag.h | ||
| tar.h | ||
| tempfile.c | ||
| tempfile.h | ||
| thread-utils.c | ||
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| tmp-objdir.c | ||
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| trailer.c | ||
| trailer.h | ||
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| tree.h | ||
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| unimplemented.sh | ||
| unix-socket.c | ||
| unix-socket.h | ||
| unix-stream-server.c | ||
| unix-stream-server.h | ||
| unpack-trees.c | ||
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| upload-pack.c | ||
| upload-pack.h | ||
| url.c | ||
| url.h | ||
| urlmatch.c | ||
| urlmatch.h | ||
| usage.c | ||
| userdiff.c | ||
| userdiff.h | ||
| utf8.c | ||
| utf8.h | ||
| varint.c | ||
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| version.c | ||
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| walker.h | ||
| wildmatch.c | ||
| wildmatch.h | ||
| worktree.c | ||
| worktree.h | ||
| wrap-for-bin.sh | ||
| wrapper.c | ||
| write-or-die.c | ||
| ws.c | ||
| wt-status.c | ||
| wt-status.h | ||
| xdiff-interface.c | ||
| xdiff-interface.h | ||
| zlib.c | ||
README.md
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.
Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.
See Documentation/gittutorial.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-<commandname>.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.txt
(man gitcvs-migration or git help cvs-migration if git is
installed).
The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission). To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org. The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.
Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (depending on your mood):
- random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
- "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks