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fb63d7f889
Earlier in commit 0781b8a9b2fe760fc4ed519a3a26e4b9bd6ccffe
(add_file_to_index: skip rehashing if the cached stat already
matches), add_file_to_index() were taught not to re-add the path
if it already matches the index.
The change meant well, but was not executed quite right. It
used ie_modified() to see if the file on the work tree is really
different from the index, and skipped adding the contents if the
function says "not modified".
This was wrong. There are three possible comparison results
between the index and the file in the work tree:
- with lstat(2) we _know_ they are different. E.g. if the
length or the owner in the cached stat information is
different from the length we just obtained from lstat(2), we
can tell the file is modified without looking at the actual
contents.
- with lstat(2) we _know_ they are the same. The same length,
the same owner, the same everything (but this has a twist, as
described below).
- we cannot tell from lstat(2) information alone and need to go
to the filesystem to actually compare.
The last case arises from what we call 'racy git' situation,
that can be caused with this sequence:
$ echo hello >file
$ git add file
$ echo aeiou >file ;# the same length
If the second "echo" is done within the same filesystem
timestamp granularity as the first "echo", then the timestamp
recorded by "git add" and the timestamp we get from lstat(2)
will be the same, and we can mistakenly say the file is not
modified. The path is called 'racily clean'. We need to
reliably detect racily clean paths are in fact modified.
To solve this problem, when we write out the index, we mark the
index entry that has the same timestamp as the index file itself
(that is the time from the point of view of the filesystem) to
tell any later code that does the lstat(2) comparison not to
trust the cached stat info, and ie_modified() then actually goes
to the filesystem to compare the contents for such a path.
That's all good, but it should not be used for this "git add"
optimization, as the goal of "git add" is to actually update the
path in the index and make it stat-clean. With the false
optimization, we did _not_ cause any data loss (after all, what
we failed to do was only to update the cached stat information),
but it made the following sequence leave the file stat dirty:
$ echo hello >file
$ git add file
$ echo hello >file ;# the same contents
$ git add file
The solution is not to use ie_modified() which goes to the
filesystem to see if it is really clean, but instead use
ie_match_stat() with "assume racily clean paths are dirty"
option, to force re-adding of such a path.
There was another problem with "git add -u". The codepath
shares the same issue when adding the paths that are found to be
modified, but in addition, it asked "git diff-files" machinery
run_diff_files() function (which is "git diff-files") to list
the paths that are modified. But "git diff-files" machinery
uses the same ie_modified() call so that it does not report
racily clean _and_ actually clean paths as modified, which is
not what we want.
The patch allows the callers of run_diff_files() to pass the
same "assume racily clean paths are dirty" option, and makes
"git-add -u" codepath to use that option, to discover and re-add
racily clean _and_ actually clean paths.
We could further optimize on top of this patch to differentiate
the case where the path really needs re-adding (i.e. the content
of the racily clean entry was indeed different) and the case
where only the cached stat information needs to be refreshed
(i.e. the racily clean entry was actually clean), but I do not
think it is worth it.
This patch applies to maint and all the way up.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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| arm | ||
| compat | ||
| contrib | ||
| Documentation | ||
| git-gui | ||
| gitweb | ||
| mozilla-sha1 | ||
| perl | ||
| ppc | ||
| t | ||
| templates | ||
| xdiff | ||
| .gitignore | ||
| .mailmap | ||
| alloc.c | ||
| archive-tar.c | ||
| archive-zip.c | ||
| archive.h | ||
| attr.c | ||
| attr.h | ||
| base85.c | ||
| blob.c | ||
| blob.h | ||
| builtin-add.c | ||
| builtin-annotate.c | ||
| builtin-apply.c | ||
| builtin-archive.c | ||
| builtin-blame.c | ||
| builtin-branch.c | ||
| builtin-bundle.c | ||
| builtin-cat-file.c | ||
| builtin-check-attr.c | ||
| builtin-check-ref-format.c | ||
| builtin-checkout-index.c | ||
| builtin-commit-tree.c | ||
| builtin-config.c | ||
| builtin-count-objects.c | ||
| builtin-describe.c | ||
| builtin-diff-files.c | ||
| builtin-diff-index.c | ||
| builtin-diff-tree.c | ||
| builtin-diff.c | ||
| builtin-fetch--tool.c | ||
| builtin-fmt-merge-msg.c | ||
| builtin-for-each-ref.c | ||
| builtin-fsck.c | ||
| builtin-gc.c | ||
| builtin-grep.c | ||
| builtin-init-db.c | ||
| builtin-log.c | ||
| builtin-ls-files.c | ||
| builtin-ls-tree.c | ||
| builtin-mailinfo.c | ||
| builtin-mailsplit.c | ||
| builtin-merge-base.c | ||
| builtin-merge-file.c | ||
| builtin-mv.c | ||
| builtin-name-rev.c | ||
| builtin-pack-objects.c | ||
| builtin-pack-refs.c | ||
| builtin-prune-packed.c | ||
| builtin-prune.c | ||
| builtin-push.c | ||
| builtin-read-tree.c | ||
| builtin-reflog.c | ||
| builtin-rerere.c | ||
| builtin-rev-list.c | ||
| builtin-rev-parse.c | ||
| builtin-revert.c | ||
| builtin-rm.c | ||
| builtin-runstatus.c | ||
| builtin-shortlog.c | ||
| builtin-show-branch.c | ||
| builtin-show-ref.c | ||
| builtin-stripspace.c | ||
| builtin-symbolic-ref.c | ||
| builtin-tag.c | ||
| builtin-tar-tree.c | ||
| builtin-unpack-objects.c | ||
| builtin-update-index.c | ||
| builtin-update-ref.c | ||
| builtin-upload-archive.c | ||
| builtin-verify-pack.c | ||
| builtin-verify-tag.c | ||
| builtin-write-tree.c | ||
| builtin.h | ||
| cache-tree.c | ||
| cache-tree.h | ||
| cache.h | ||
| check-builtins.sh | ||
| check-racy.c | ||
| color.c | ||
| color.h | ||
| combine-diff.c | ||
| commit.c | ||
| commit.h | ||
| config.c | ||
| config.mak.in | ||
| configure.ac | ||
| connect.c | ||
| convert-objects.c | ||
| convert.c | ||
| copy.c | ||
| COPYING | ||
| csum-file.c | ||
| csum-file.h | ||
| ctype.c | ||
| daemon.c | ||
| date.c | ||
| decorate.c | ||
| decorate.h | ||
| delta.h | ||
| diff-delta.c | ||
| diff-lib.c | ||
| diff.c | ||
| diff.h | ||
| diffcore-break.c | ||
| diffcore-delta.c | ||
| diffcore-order.c | ||
| diffcore-pickaxe.c | ||
| diffcore-rename.c | ||
| diffcore.h | ||
| dir.c | ||
| dir.h | ||
| dump-cache-tree.c | ||
| entry.c | ||
| environment.c | ||
| exec_cmd.c | ||
| exec_cmd.h | ||
| fast-import.c | ||
| fetch-pack.c | ||
| fetch.c | ||
| fetch.h | ||
| fixup-builtins | ||
| generate-cmdlist.sh | ||
| git-add--interactive.perl | ||
| git-am.sh | ||
| git-archimport.perl | ||
| git-bisect.sh | ||
| git-checkout.sh | ||
| git-clean.sh | ||
| git-clone.sh | ||
| git-commit.sh | ||
| git-compat-util.h | ||
| git-cvsexportcommit.perl | ||
| git-cvsimport.perl | ||
| git-cvsserver.perl | ||
| git-fetch.sh | ||
| git-filter-branch.sh | ||
| git-instaweb.sh | ||
| git-lost-found.sh | ||
| git-ls-remote.sh | ||
| git-merge-octopus.sh | ||
| git-merge-one-file.sh | ||
| git-merge-ours.sh | ||
| git-merge-resolve.sh | ||
| git-merge-stupid.sh | ||
| git-merge.sh | ||
| git-mergetool.sh | ||
| git-parse-remote.sh | ||
| git-pull.sh | ||
| git-quiltimport.sh | ||
| git-rebase--interactive.sh | ||
| git-rebase.sh | ||
| git-relink.perl | ||
| git-remote.perl | ||
| git-repack.sh | ||
| git-request-pull.sh | ||
| git-reset.sh | ||
| git-send-email.perl | ||
| git-sh-setup.sh | ||
| git-stash.sh | ||
| git-submodule.sh | ||
| git-svn.perl | ||
| git-svnimport.perl | ||
| GIT-VERSION-GEN | ||
| git.c | ||
| git.spec.in | ||
| gitk | ||
| grep.c | ||
| grep.h | ||
| hash-object.c | ||
| help.c | ||
| http-fetch.c | ||
| http-push.c | ||
| http.c | ||
| http.h | ||
| ident.c | ||
| imap-send.c | ||
| index-pack.c | ||
| INSTALL | ||
| interpolate.c | ||
| interpolate.h | ||
| list-objects.c | ||
| list-objects.h | ||
| local-fetch.c | ||
| lockfile.c | ||
| log-tree.c | ||
| log-tree.h | ||
| mailmap.c | ||
| mailmap.h | ||
| Makefile | ||
| match-trees.c | ||
| merge-file.c | ||
| merge-index.c | ||
| merge-recursive.c | ||
| merge-tree.c | ||
| mktag.c | ||
| mktree.c | ||
| object-refs.c | ||
| object.c | ||
| object.h | ||
| pack-check.c | ||
| pack-redundant.c | ||
| pack-write.c | ||
| pack.h | ||
| pager.c | ||
| patch-delta.c | ||
| patch-id.c | ||
| patch-ids.c | ||
| patch-ids.h | ||
| path-list.c | ||
| path-list.h | ||
| path.c | ||
| peek-remote.c | ||
| pkt-line.c | ||
| pkt-line.h | ||
| progress.c | ||
| progress.h | ||
| quote.c | ||
| quote.h | ||
| reachable.c | ||
| reachable.h | ||
| read-cache.c | ||
| README | ||
| receive-pack.c | ||
| reflog-walk.c | ||
| reflog-walk.h | ||
| refs.c | ||
| refs.h | ||
| RelNotes | ||
| remote.c | ||
| remote.h | ||
| revision.c | ||
| revision.h | ||
| rsh.c | ||
| rsh.h | ||
| run-command.c | ||
| run-command.h | ||
| send-pack.c | ||
| server-info.c | ||
| setup.c | ||
| sha1_file.c | ||
| sha1_name.c | ||
| shallow.c | ||
| shell.c | ||
| show-index.c | ||
| sideband.c | ||
| sideband.h | ||
| ssh-fetch.c | ||
| ssh-pull.c | ||
| ssh-push.c | ||
| ssh-upload.c | ||
| strbuf.c | ||
| strbuf.h | ||
| symlinks.c | ||
| tag.c | ||
| tag.h | ||
| tar.h | ||
| test-absolute-path.c | ||
| test-chmtime.c | ||
| test-date.c | ||
| test-delta.c | ||
| test-genrandom.c | ||
| test-match-trees.c | ||
| test-sha1.c | ||
| test-sha1.sh | ||
| trace.c | ||
| tree-diff.c | ||
| tree-walk.c | ||
| tree-walk.h | ||
| tree.c | ||
| tree.h | ||
| unpack-file.c | ||
| unpack-trees.c | ||
| unpack-trees.h | ||
| update-server-info.c | ||
| upload-pack.c | ||
| usage.c | ||
| utf8.c | ||
| utf8.h | ||
| var.c | ||
| write_or_die.c | ||
| wt-status.c | ||
| wt-status.h | ||
| xdiff-interface.c | ||
| xdiff-interface.h | ||
//////////////////////////////////////////////////////////////// GIT - the stupid content tracker //////////////////////////////////////////////////////////////// "git" can mean anything, 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 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. It was originally written by Linus Torvalds with help of a group of hackers around the net. It is currently maintained by Junio C Hamano. Please read the file INSTALL for installation instructions. See Documentation/tutorial.txt to get started, then see Documentation/everyday.txt for a useful minimum set of commands, and "man git-commandname" for documentation of each command. CVS users may also want to read Documentation/cvs-migration.txt. Many Git online resources are accessible from http://git.or.cz/ including full documentation and Git related tools. 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. 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 http://marc.theaimsgroup.com/?l=git and other archival sites. The messages titled "A note from the maintainer", "What's in git.git (stable)" and "What's cooking in git.git (topics)" and the discussion following them on the mailing list give a good reference for project status, development direction and remaining tasks.