When check_leading_path notices a file in the way of a new entry to be
checked out, verify_absent uses (1) the mode to determine whether it
is a directory (2) the rest of the stat information to check if this
is actually an old entry, disguised by a change in filename (e.g.,
README -> Readme) that is significant to git but insignificant to the
underlying filesystem. If lstat fails, these checks are performed
with an uninitialied stat structure, producing essentially random
results.
Better to just error out when lstat fails.
The easiest way to reproduce this is to remove a file after the
check_leading_path call and before the lstat in verify_absent. An
lstat failure other than ENOENT in check_leading_path would also
trigger the same code path.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When check_leading_path notices no file in the way of the new entry to
be checked out, verify_absent checks whether there is a directory
there or nothing at all. If that lstat call fails (for example due to
ENOMEM), it assumes ENOENT, meaning a directory with untracked files
would be clobbered in that case.
Check errno after calling lstat, and for conditions other than ENOENT,
just error out.
This is a theoretical race condition. lstat has to succeed moments
before it fails for there to be trouble.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
unpack_trees() merges two trees (the current HEAD and the destination
commit) when switching to another branch, checking and updating the index
entry where the destination differs from the current HEAD. It merges three
trees (the common ancestor, the current HEAD and the other commit) when
performing a three-way merge, checking and updating the index entry when
the merge result differs from the current HEAD. It does so by walking the
input trees in parallel all the way down to the leaves.
One common special case is a directory is identical across the trees
involved in the merge. In such a case, we do not have to descend into the
directory at all---we know that the end result is to keep the entries in
the current index.
This optimization cannot be applied in a few special cases in
unpack_trees(), though. We need to descend into the directory and update
the index entries from the target tree in the following cases:
- When resetting (e.g. "git reset --hard"); and
- When checking out a tree for the first time into an empty working tree
(e.g. "git read-tree -m -u HEAD HEAD" with missing .git/index).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* nd/maint-fix-add-typo-detection:
Revert "excluded_1(): support exclude files in index"
unpack-trees: fix sparse checkout's "unable to match directories"
unpack-trees: move all skip-worktree checks back to unpack_trees()
dir.c: add free_excludes()
cache.h: realign and use (1 << x) form for CE_* constants
An aborted merge prints the list of rejected paths as part of the
error message. Since commit f66caaf9 (do not overwrite files in
leading path), some of those paths do not have static buffers, so
we have to keep a copy. Use string_list's to accomplish this.
This changes the order of the list to the order in which the paths
are processed. Previously, it was reversed.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the work tree contains an untracked file x, and
unpack-trees wants to checkout a path x/*, the
file x is removed unconditionally.
Instead, apply the same checks that are normally
used for untracked files, and abort if the file
cannot be removed.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This wraps some inline code into the function check_ok_to_remove(),
which will later be used for leading path components as well.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Matching index entries against an excludes file currently has two
problems.
First, there's no function to do it. Code paths (like sparse
checkout) that wanted to try it would iterate over index entries and
for each index entry pass that path to excluded_from_list(). But that
is not how excluded_from_list() works; one is supposed to feed in each
ancester of a path before a given path to find out if it was excluded
because of some parent or grandparent matching a
bigsubdirectory/
pattern despite the path not matching any .gitignore pattern directly.
Second, it's inefficient. The excludes mechanism is supposed to let
us block off vast swaths of the filesystem as uninteresting; separately
checking every index entry doesn't fit that model.
Introduce a new function to take care of both these problems. This
traverses the index in depth-first order (well, that's what order the
index is in) to mark un-excluded entries.
Maybe some day the in-core index format will be restructured to make
this sort of operation easier. Or maybe we will want to try some
binary search based thing. The interface is simple enough to allow
all those things. Example:
clear_ce_flags(the_index.cache, the_index.cache_nr,
CE_CANDIDATE, CE_CLEARME, exclude_list);
would clear the CE_CLEARME flag on all index entries with
CE_CANDIDATE flag and not matched by exclude_list.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Earlier, the will_have_skip_worktree() checks are done in various
places, which makes it hard to traverse the index tree-alike, required
by excluded_from_list(). This patch moves all the checks into two
loops in unpack_trees().
Entries in index in this operation can be classified into two
groups: ones already in index before unpack_trees() is called and ones
added to index after traverse_trees() is called.
In both groups, before checking file status on worktree, the future
skip-worktree bit must be checked, so that if an entry will be outside
worktree, worktree should not be checked.
For the first group, the future skip-worktree bit is precomputed and
stored as CE_NEW_SKIP_WORKTREE in the first loop before
traverse_trees() is called so that *way_merge() function does not need
to compute it again.
For the second group, because we don't know what entries will be in
this group until traverse_trees() finishes, operations that need
future skip-worktree check is delayed until CE_NEW_SKIP_WORKTREE is
computed in the second loop. CE_ADDED is used to mark entries in the
second group.
CE_ADDED and CE_NEW_SKIP_WORKTREE are temporary flags used in
unpack_trees(). CE_ADDED is only used by add_to_index(), which should
not be called while unpack_trees() is running.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An aborted merge prints the list of rejected paths as part of the
error message. Since commit f66caaf9 (do not overwrite files in
leading path), some of those paths do not have static buffers, so
we have to keep a copy. Use string_list's to accomplish this.
This changes the order of the list to the order in which the paths
are processed. Previously, it was reversed.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the work tree contains an untracked file x, and
unpack-trees wants to checkout a path x/*, the
file x is removed unconditionally.
Instead, apply the same checks that are normally
used for untracked files, and abort if the file
cannot be removed.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
This wraps some inline code into the function check_ok_to_remove(),
which will later be used for leading path components as well.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
* dg/local-mod-error-messages:
t7609-merge-co-error-msgs: test non-fast forward case too.
Move "show_all_errors = 1" to setup_unpack_trees_porcelain()
setup_unpack_trees_porcelain: take the whole options struct as parameter
Move set_porcelain_error_msgs to unpack-trees.c and rename it
Conflicts:
merge-recursive.c
Not only this makes the code clearer since setting up the porcelain error
message is meant to work with show_all_errors, but this fixes a call to
setup_unpack_trees_porcelain() in git_merge_trees() which did not set
show_all_errors.
add_rejected_path() used to double-check whether it was running in
plumbing mode. This check was ineffective since it was setting
show_all_errors too late for traverse_trees() to see it, and is made
useless by this patch. Remove it.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a preparation patch to let setup_unpack_trees_porcelain set
show_all_errors itself.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function is currently dealing only with error messages, but the
intent of calling it is really to notify the unpack-tree mechanics that
it is running in porcelain mode.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* nd/fix-sparse-checkout:
unpack-trees: mark new entries skip-worktree appropriately
unpack-trees: do not check for conflict entries too early
unpack-trees: let read-tree -u remove index entries outside sparse area
unpack-trees: only clear CE_UPDATE|CE_REMOVE when skip-worktree is always set
t1011 (sparse checkout): style nitpicks
* dg/local-mod-error-messages:
t7609: test merge and checkout error messages
unpack_trees: group error messages by type
merge-recursive: distinguish "removed" and "overwritten" messages
merge-recursive: porcelain messages for checkout
Turn unpack_trees_options.msgs into an array + enum
Conflicts:
t/t3400-rebase.sh
When an error is encountered, it calls add_rejected_file() which either
- directly displays the error message and stops if in plumbing mode
(i.e. if show_all_errors is not initialized at 1)
- or stores it so that it will be displayed at the end with display_error_msgs(),
Storing the files by error type permits to have a list of files for
which there is the same error instead of having a serie of almost
identical errors.
As each bind_overlap error combines a file and an old file, a list cannot be
done, therefore, theses errors are not stored but directly displayed.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To limit the number of possible error messages, the error messages for
the case would_lose_untracked_file and would_lose_orphaned in
unpack_trees_options.msgs were handled with a single string,
parameterized by an action string ("overwritten" or "removed").
Instead, we consider them as two different cases, with unparameterized
string. This will make it easier to make separate lists sorted by error
types later.
Only the bind_overlap case still takes two %s parameters, but that's
unavoidable.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A porcelain message was first added in checkout.c in the commit
8ccba008 (Junio C Hamano, Sat May 17 21:03:49 2008, unpack-trees:
allow Porcelain to give different error messages) to give better feedback
in the case of merge errors.
This patch adapts the porcelain messages for the case of checkout
instead. This way, when having a checkout error, "merge" no longer
appears in the error message.
While we're there, we add an advice in the case of
would_lose_untracked_file.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The list of error messages was introduced as a structure, but an array
indexed over an enum is more flexible, since it allows one to store a
type of error message (index in the array) in a variable.
This change needs to rename would_lose_untracked ->
would_lose_untracked_file to avoid a clash with the function
would_lose_untracked in merge-recursive.c.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The underlying problem is that the fill_tree_descriptor()
API is easy to misuse, and this patch does not fix that.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Sparse checkout narrows worktree down based on the skip-worktree bit
before and after $GIT_DIR/info/sparse-checkout application. If it does
not have that bit before but does after, a narrow is detected and the
file will be removed from worktree.
New files added by merge, however, does not have skip-worktree bit. If
those files appear to be outside checkout area, the same rule applies:
the file gets removed from worktree even though they don't exist in
worktree.
Just pretend they have skip-worktree before in that case, so the rule
is ignored.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The idea of sparse checkout is conflict entries should always stay
in worktree, regardless $GIT_DIR/info/sparse-checkout. Therefore,
ce_stage(ce) usually means no CE_SKIP_WORKTREE. This is true when all
entries have been merged into the index, and identical staged entries
collapsed.
However, will_have_skip_worktree() since f1f523e (unpack-trees():
ignore worktree check outside checkout area) is also used earlier in
verify_* functions, where entries have not been merged to index yet
and ce_stage() is not zero. Checking ce_stage() then may provoke
unnecessary verification on entries outside checkout area and error
out.
This fixes part of test case "read-tree adds to worktree, dirty case".
The error
error: Untracked working tree file 'sub/added' would be overwritten by merge.
is now gone and (unfortunately) replaced by another error, which will
be addressed in the next patch.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To avoid touching the worktree outside a sparse checkout,
when the update flag is enabled unpack_trees() clears the
CE_UPDATE and CE_REMOVE flags on entries that do not match the
sparse pattern before actually committing any updates to the
index file or worktree.
The effect on the index was unintentional; sparse checkout was
never meant to prevent index updates outside the area checked
out. And the result is very confusing: for example, after a
failed merge, currently "git reset --hard" does not reset the
state completely but an additional "git reset --mixed" will.
So stop clearing the CE_REMOVE flag. Instead, maintain a
CE_WT_REMOVE flag to separately track whether a particular
file removal should apply to the worktree in addition to the
index or not.
The CE_WT_REMOVE flag is used already to mark files that
should be removed because of a narrowing checkout area. That
usage will still apply; do not clear the CE_WT_REMOVE flag
in that case (detectable because the CE_REMOVE flag is not
set).
This bug masked some other bugs illustrated by the test
suite, which will be addressed by later patches.
Reported-by: Frédéric Brière <fbriere@fbriere.net>
Fixes: http://bugs.debian.org/583699
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The purpose of this clearing is, as explained in comment, because
verify_*() may set those bits before apply_sparse_checkout() is
called. By that time, it's not clear whether an entry will stay in
checkout area or out. After $GIT_DIR/info/sparse-checkout is applied,
we know what entries will be in finally. It's time to clean unwanted
bits.
That works perfectly when checkout area remains unchanged. When
checkout area changes, apply_sparse_checkout() may set CE_UPDATE
or CE_WT_REMOVE to widen/narrow checkout area. Doing the clearing
after apply_sparse_checkout() may clear those widening/narrowing
bits unexpectedly.
So, only do that on entries that are not affected by checkout area
changes (i.e. skip-worktree bit does not change after
apply_sparse_checkout).
This code does not actually fix anything though, just
future-proof. The removed code and the narrow/widen code inside
apply_sparse_checkout are currently independent (narrow code never
sets CE_REMOVE, widen code sets CE_UPDATE, but ce_skip_worktree()
would be false).
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* gv/portable:
test-lib: use DIFF definition from GIT-BUILD-OPTIONS
build: propagate $DIFF to scripts
Makefile: Tru64 portability fix
Makefile: HP-UX 10.20 portability fixes
Makefile: HPUX11 portability fixes
Makefile: SunOS 5.6 portability fix
inline declaration does not work on AIX
Allow disabling "inline"
Some platforms lack socklen_t type
Make NO_{INET_NTOP,INET_PTON} configured independently
Makefile: some platforms do not have hstrerror anywhere
git-compat-util.h: some platforms with mmap() lack MAP_FAILED definition
test_cmp: do not use "diff -u" on platforms that lack one
fixup: do not unconditionally disable "diff -u"
tests: use "test_cmp", not "diff", when verifying the result
Do not use "diff" found on PATH while building and installing
enums: omit trailing comma for portability
Makefile: -lpthread may still be necessary when libc has only pthread stubs
Rewrite dynamic structure initializations to runtime assignment
Makefile: pass CPPFLAGS through to fllow customization
Conflicts:
Makefile
wt-status.h
When traversing trees with an index, the current index pointer
(o->cache_bottom) occasionally has to be temporarily advanced forwards to
match the traversal order of the tree, which is not the same as the sort
order of the index. The existing algorithm that did this (introduced in
730f72840c) would get "stuck" when the
cache_bottom was popped and then repeatedly check the same index entries
over and over. This represents a serious performance regression for
large repositories compared to the old "broken" traversal order.
This commit makes a simple change to mitigate this. Whenever
find_cache_pos sees that the current pos is also the cache_bottom, and
it has already been unpacked, it advances the cache_bottom as well as
the current pos. This prevents the above "sticking" behavior without
dramatically changing the algorithm.
In addition, this commit moves the unpacked check above the
ce_in_traverse_path() check. The simple bitmask check is cheaper, and
in the case described above will be firing quite a bit to advance the
cache_bottom after a tree pop.
This yields considerable performance improvements for large trees.
The following are the number of function calls for "git diff HEAD" on
the Linux kernel tree, with 33,307 files:
Symbol Calls Before Calls After
------------------- ------------ -----------
unpack_callback 35,332 35,332
find_cache_pos 37,357 37,357
ce_in_traverse_path 4,979,473 37,357
do_compare_entry 6,828,181 251,925
df_name_compare 6,828,181 251,925
And on a repository of 187,456 files:
Symbol Calls Before Calls After
------------------- ------------ -----------
unpack_callback 197,958 197,958
find_cache_pos 208,460 208,460
ce_in_traverse_path 37,308,336 208,460
do_compare_entry 156,950,469 2,690,626
df_name_compare 156,950,469 2,690,626
On the latter repository, user time for "git diff HEAD" was reduced from
5.58 to 0.42 seconds. This is compared to 0.30 seconds before the
traversal order fix was implemented.
Signed-off-by: Brian Downing <bdowning@lavos.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Unfortunately, there are still plenty of production systems with
vendor compilers that choke unless all compound declarations can be
determined statically at compile time, for example hpux10.20 (I can
provide a comprehensive list of our supported platforms that exhibit
this problem if necessary).
This patch simply breaks apart any compound declarations with dynamic
initialisation expressions, and moves the initialisation until after
the last declaration in the same block, in all the places necessary to
have the offending compilers accept the code.
Signed-off-by: Gary V. Vaughan <gary@thewrittenword.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A merge will fail gracefully if it needs to update files marked
"assume unchanged", but other similar commands will not. In
particular, checkout and rebase will silently overwrite changes to
such files.
This is a regression introduced in commit 1dcafcc0 (verify_uptodate():
add ce_uptodate(ce) test), which avoids lstat's during a merge, if the
index entry is up-to-date. If the CE_VALID flag is set, however, we
cannot trust CE_UPTODATE.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch introduces the remove_or_warn function which is a
generalised version of the {unlink,rmdir}_or_warn functions. It takes
an additional parameter indicating the mode of the file to be removed.
The patch also modifies certain functions to use remove_or_warn
where appropriate, and adds a test case for a bug fixed by the use
of remove_or_warn.
Signed-off-by: Peter Collingbourne <peter@pcc.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jc/fix-tree-walk:
read-tree --debug-unpack
unpack-trees.c: look ahead in the index
unpack-trees.c: prepare for looking ahead in the index
Aggressive three-way merge: fix D/F case
traverse_trees(): handle D/F conflict case sanely
more D/F conflict tests
tests: move convenience regexp to match object names to test-lib.sh
Conflicts:
builtin-read-tree.c
unpack-trees.c
unpack-trees.h
* cc/reset-more:
t7111: check that reset options work as described in the tables
Documentation: reset: add some missing tables
Fix bit assignment for CE_CONFLICTED
"reset --merge": fix unmerged case
reset: use "unpack_trees()" directly instead of "git read-tree"
reset: add a few tests for "git reset --merge"
Documentation: reset: add some tables to describe the different options
reset: improve mixed reset error message when in a bare repo
* nd/sparse: (25 commits)
t7002: test for not using external grep on skip-worktree paths
t7002: set test prerequisite "external-grep" if supported
grep: do not do external grep on skip-worktree entries
commit: correctly respect skip-worktree bit
ie_match_stat(): do not ignore skip-worktree bit with CE_MATCH_IGNORE_VALID
tests: rename duplicate t1009
sparse checkout: inhibit empty worktree
Add tests for sparse checkout
read-tree: add --no-sparse-checkout to disable sparse checkout support
unpack-trees(): ignore worktree check outside checkout area
unpack_trees(): apply $GIT_DIR/info/sparse-checkout to the final index
unpack-trees(): "enable" sparse checkout and load $GIT_DIR/info/sparse-checkout
unpack-trees.c: generalize verify_* functions
unpack-trees(): add CE_WT_REMOVE to remove on worktree alone
Introduce "sparse checkout"
dir.c: export excluded_1() and add_excludes_from_file_1()
excluded_1(): support exclude files in index
unpack-trees(): carry skip-worktree bit over in merged_entry()
Read .gitignore from index if it is skip-worktree
Avoid writing to buffer in add_excludes_from_file_1()
...
Conflicts:
.gitignore
Documentation/config.txt
Documentation/git-update-index.txt
Makefile
entry.c
t/t7002-grep.sh
Change the unlink_entry function to use rmdir to remove submodule
directories. Currently we try to use unlink, which will never succeed.
Of course rmdir will only succeed for empty (i.e. not checked out)
submodule directories. Behaviour if a submodule is checked out stays
essentially the same: print a warning message and keep the submodule
directory.
Signed-off-by: Peter Collingbourne <peter@pcc.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This makes the traversal of index be in sync with the tree traversal.
When unpack_callback() is fed a set of tree entries from trees, it
inspects the name of the entry and checks if the an index entry with
the same name could be hiding behind the current index entry, and
(1) if the name appears in the index as a leaf node, it is also
fed to the n_way_merge() callback function;
(2) if the name is a directory in the index, i.e. there are entries in
that are underneath it, then nothing is fed to the n_way_merge()
callback function;
(3) otherwise, if the name comes before the first eligible entry in the
index, the index entry is first unpacked alone.
When traverse_trees_recursive() descends into a subdirectory, the
cache_bottom pointer is moved to walk index entries within that directory.
All of these are omitted for diff-index, which does not even want to be
fed an index entry and a tree entry with D/F conflicts.
This fixes 3-way read-tree and exposes a bug in other parts of the system
in t6035, test #5. The test prepares these three trees:
O = HEAD^
100644 blob e69de29bb2 a/b-2/c/d
100644 blob e69de29bb2 a/b/c/d
100644 blob e69de29bb2 a/x
A = HEAD
100644 blob e69de29bb2 a/b-2/c/d
100644 blob e69de29bb2 a/b/c/d
100644 blob 587be6b4c3f93f93c489c0111bba5596147a26cb a/x
B = master
120000 blob a36b77384451ea1de7bd340ffca868249626bc52 a/b
100644 blob e69de29bb2 a/b-2/c/d
100644 blob e69de29bb2 a/x
With a clean index that matches HEAD, running
git read-tree -m -u --aggressive $O $A $B
now yields
120000 a36b77384451ea1de7bd340ffca868249626bc52 3 a/b
100644 e69de29bb2 0 a/b-2/c/d
100644 e69de29bb2 1 a/b/c/d
100644 e69de29bb2 2 a/b/c/d
100644 587be6b4c3f93f93c489c0111bba5596147a26cb 0 a/x
which is correct. "master" created "a/b" symlink that did not exist,
and removed "a/b/c/d" while HEAD did not do touch either path.
Before this series, read-tree did not notice the situation and resolved
addition of "a/b" and removal of "a/b/c/d" independently. If A = HEAD had
another path "a/b/c/e" added, this merge should conflict but instead it
silently resolved "a/b" and then immediately overwrote it to add
"a/b/c/e", which was quite bogus.
Tests in t1012 start to work with this.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This prepares but does not yet implement a look-ahead in the index entries
when traverse-trees.c decides to give us tree entries in an order that
does not match what is in the index.
A case where a look-ahead in the index is necessary happens when merging
branch B into branch A while the index matches the current branch A, using
a tree O as their common ancestor, and these three trees looks like this:
O A B
t t
t-i t-i t-i
t-j t-j
t/1
t/2
The traverse_trees() function gets "t", "t-i" and "t" from trees O, A and
B first, and notices that A may have a matching "t" behind "t-i" and "t-j"
(indeed it does), and tells A to give that entry instead. After unpacking
blob "t" from tree B (as it hasn't changed since O in B and A removed it,
it will result in its removal), it descends into directory "t/".
The side that walked index in parallel to the tree traversal used to be
implemented with one pointer, o->pos, that points at the next index entry
to be processed. When this happens, the pointer o->pos still points at
"t-i" that is the first entry. We should be able to skip "t-i" and "t-j"
and locate "t/1" from the index while the recursive invocation of
traverse_trees() walks and match entries found there, and later come back
to process "t-i".
While that look-ahead is not implemented yet, this adds a flag bit,
CE_UNPACKED, to mark the entries in the index that has already been
processed. o->pos pointer has been renamed to o->cache_bottom and it
points at the first entry that may still need to be processed.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the ancestor used to have a blob "P", your tree removed it, and the
tree you are merging with also removed it, the agressive three-way cleanly
merges to remove that blob. If the other tree added a new blob "P/Q"
while removing "P", it should also merge cleanly to remove "P" and create
"P/Q" (since neither the ancestor nor your tree could have had it, so it
is a typical "created in one").
The "aggressive" rule is not new anymore. Reword the stale comment.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 9e8ecea (Add 'merge' mode to 'git reset', 2008-12-01) disallowed
"git reset --merge" when there was unmerged entries. But it wished if
unmerged entries were reset as if --hard (instead of --merge) has been
used. This makes sense because all "mergy" operations makes sure that
any path involved in the merge does not have local modifications before
starting, so resetting such a path away won't lose any information.
The previous commit changed the behavior of --merge to accept resetting
unmerged entries if they are reset to a different state than HEAD, but it
did not reset the changes in the work tree, leaving the conflict markers
in the resulting file in the work tree.
Fix it by doing three things:
- Update the documentation to match the wish of original "reset --merge"
better, namely, "An unmerged entry is a sign that the path didn't have
any local modification and can be safely resetted to whatever the new
HEAD records";
- Update read_index_unmerged(), which reads the index file into the cache
while dropping any higher-stage entries down to stage #0, not to copy
the object name from the higher stage entry. The code used to take the
object name from the a stage entry ("base" if you happened to have
stage #1, or "ours" if both sides added, etc.), which essentially meant
that you are getting random results depending on what the merge did.
The _only_ reason we want to keep a previously unmerged entry in the
index at stage #0 is so that we don't forget the fact that we have
corresponding file in the work tree in order to be able to remove it
when the tree we are resetting to does not have the path. In order to
differentiate such an entry from ordinary cache entry, the cache entry
added by read_index_unmerged() is marked as CE_CONFLICTED.
- Update merged_entry() and deleted_entry() so that they pay attention to
cache entries marked as CE_CONFLICTED. They are previously unmerged
entries, and the files in the work tree that correspond to them are
resetted away by oneway_merge() to the version from the tree we are
resetting to.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previously CE_MATCH_IGNORE_VALID flag is used by both valid and
skip-worktree bits. While the two bits have similar behaviour, sharing
this flag means "git update-index --really-refresh" will ignore
skip-worktree while it should not. Instead another flag is
introduced to ignore skip-worktree bit, CE_MATCH_IGNORE_VALID only
applies to valid bit.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When unpack_index_entry() failed, consistently call unpack_failed(),
instead of silently returning -1.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The way sparse checkout works, users may empty their worktree
completely, because of non-matching sparse-checkout spec, or empty
spec. I believe this is not desired. This patch makes Git refuse to
produce such worktree.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
verify_absent() and verify_uptodate() are used to ensure worktree
is safe to be updated, then CE_REMOVE or CE_UPDATE will be set.
Finally check_updates() bases on CE_REMOVE, CE_UPDATE and the
recently added CE_WT_REMOVE to update working directory accordingly.
The entries that are checked may eventually be left out of checkout
area (done later in apply_sparse_checkout()). We don't want to update
outside checkout area. This patch teaches Git to assume "good",
skip these checks when it's sure those entries will be outside checkout
area, and clear CE_REMOVE|CE_UPDATE that could be set due to this
assumption.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch introduces core.sparseCheckout, which will control whether
sparse checkout support is enabled in unpack_trees()
It also loads sparse-checkout file that will be used in the next patch.
I split it out so the next patch will be shorter, easier to read.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
CE_REMOVE now removes both worktree and index versions. Sparse
checkout must be able to remove worktree version while keep the
index intact when checkout area is narrowed.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In this code path, we would remove "old" and replace it with "merge".
"old" may have skip-worktree bit, so re-add it to "merge".
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This part is mainly to remove CE_VALID shortcuts (and as a
consequence, ce_uptodate() shortcuts as it may be turned on by
CE_VALID) in writing code path if skip-worktree is used. Various tests
are added to avoid future breakages.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we switch branches with "checkout -f", unpack_trees() feeds two
cache_entries to oneway_merge() function in its src[] array argument. The
zeroth entry comes from the current index, and the first entry represents
what the merge result should be, taken from the tree recorded in the
commit we are switching to.
When we have a blob (either regular file or a symlink) in the index and in
the work tree at path "foo", and the switched-to tree has "foo/bar",
i.e. "foo" becomes a directory, src[0] is obviously that blob currently
registered at "foo". Even though we do not have anything at "foo" in the
switched-to tree, src[1] is _not_ NULL in this case.
The unpack_trees() machinery places a special marker df_conflict_entry
to signal that no blob exists at "foo", but it will become a directory
that may have somthing underneath it (namely "foo/bar"), so a usual 3-way
merge can notice the situation.
But oneway_merge() codepath failed to notice this and passed the special
marker directly to merged_entry(). This happens to remove the "foo" in
the end because the df_conflict_entry does not have any name (hence the
"error" message) and its addition in add_index_entry() is rejected, but it
is wrong.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
In our 'oneway_merge()' we always do an 'lstat()' to see if we might
need to mark the entry for updating.
But we really shouldn't need to do that when the cache entry is already
marked as being ce_uptodate(), and this makes us do unnecessary lstat()
calls if we have index preloading enabled.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The c99 MIPSpro Compiler version 7.4.4m on IRIX 6.5 does not properly
initialize run-time initialized arrays. An array which is initialized with
fewer elements than the length of the array should have the unitialized
elements initialized to zero. This compiler only initializes the remaining
elements when the last element is a static parameter. So work around it
by adding a "NULL" initialization parameter.
Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stop the insanity with separate 'path' and 'base' arguments that must
match. We don't need that crazy interface any more, since we cleaned up
handling of 'path' in commit da4b3e8c28.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a few remaining ones, but this fixes the trivial ones. It boils
down to two main issues that sparse complains about:
- warning: Using plain integer as NULL pointer
Sparse doesn't like you using '0' instead of 'NULL'. For various good
reasons, not the least of which is just the visual confusion. A NULL
pointer is not an integer, and that whole "0 works as NULL" is a
historical accident and not very pretty.
A few of these remain: zlib is a total mess, and Z_NULL is just a 0.
I didn't touch those.
- warning: symbol 'xyz' was not declared. Should it be static?
Sparse wants to see declarations for any functions you export. A lack
of a declaration tends to mean that you should either add one, or you
should mark the function 'static' to show that it's in file scope.
A few of these remain: I only did the ones that should obviously just
be made static.
That 'wt_status_submodule_summary' one is debatable. It has a few related
flags (like 'wt_status_use_color') which _are_ declared, and are used by
builtin-commit.c. So maybe we'd like to export it at some point, but it's
not declared now, and not used outside of that file, so 'static' it is in
this patch.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When running "diff-index --cached" after making a change to only a small
portion of the index, there is no point unpacking unchanged subtrees into
the index recursively, only to find that all entries match anyway. Tweak
unpack_trees() logic that is used to read in the tree object to catch the
case where the tree entry we are looking at matches the index as a whole
by looking at the cache-tree.
As an exercise, after modifying a few paths in the kernel tree, here are
a few numbers on my Athlon 64X2 3800+:
(without patch, hot cache)
$ /usr/bin/time git diff --cached --raw
:100644 100644 b57e1f5... e69de29... M Makefile
:100644 000000 8c86b72... 0000000... D arch/x86/Makefile
:000000 100644 0000000... e69de29... A arche
0.07user 0.02system 0:00.09elapsed 102%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+9407minor)pagefaults 0swaps
(with patch, hot cache)
$ /usr/bin/time ../git.git/git-diff --cached --raw
:100644 100644 b57e1f5... e69de29... M Makefile
:100644 000000 8c86b72... 0000000... D arch/x86/Makefile
:000000 100644 0000000... e69de29... A arche
0.02user 0.00system 0:00.02elapsed 103%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+2446minor)pagefaults 0swaps
Cold cache numbers are very impressive, but it does not matter very much
in practice:
(without patch, cold cache)
$ su root sh -c 'echo 3 >/proc/sys/vm/drop_caches'
$ /usr/bin/time git diff --cached --raw
:100644 100644 b57e1f5... e69de29... M Makefile
:100644 000000 8c86b72... 0000000... D arch/x86/Makefile
:000000 100644 0000000... e69de29... A arche
0.06user 0.17system 0:10.26elapsed 2%CPU (0avgtext+0avgdata 0maxresident)k
247032inputs+0outputs (1172major+8237minor)pagefaults 0swaps
(with patch, cold cache)
$ su root sh -c 'echo 3 >/proc/sys/vm/drop_caches'
$ /usr/bin/time ../git.git/git-diff --cached --raw
:100644 100644 b57e1f5... e69de29... M Makefile
:100644 000000 8c86b72... 0000000... D arch/x86/Makefile
:000000 100644 0000000... e69de29... A arche
0.02user 0.01system 0:01.01elapsed 3%CPU (0avgtext+0avgdata 0maxresident)k
18440inputs+0outputs (79major+2369minor)pagefaults 0swaps
This of course helps "git status" as well.
(without patch, hot cache)
$ /usr/bin/time ../git.git/git-status >/dev/null
0.17user 0.18system 0:00.35elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+5336outputs (0major+10970minor)pagefaults 0swaps
(with patch, hot cache)
$ /usr/bin/time ../git.git/git-status >/dev/null
0.10user 0.16system 0:00.27elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+5336outputs (0major+3921minor)pagefaults 0swaps
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This helps to notice when something's going wrong, especially on
systems which lock open files.
I used the following criteria when selecting the code for replacement:
- it was already printing a warning for the unlink failures
- it is in a function which already printing something or is
called from such a function
- it is in a static function, returning void and the function is only
called from a builtin main function (cmd_)
- it is in a function which handles emergency exit (signal handlers)
- it is in a function which is obvously cleaning up the lockfiles
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jc/attributes-checkout:
Add a test for checking whether gitattributes is honored by checkout.
Read attributes from the index that is being checked out
Traditionally we used .gitattributes file from the work tree if exists,
and otherwise read from the index as a fallback. When switching to a
branch that has an updated .gitattributes file, and entries in it give
different attributes to other paths being checked out, we should instead
read from the .gitattributes in the index.
This breaks a use case of fixing incorrect entries in the .gitattributes
in the work tree (without adding it to the index) and checking other paths
out, though.
$ edit .gitattributes ;# mark foo.dat as binary
$ rm foo.dat
$ git checkout foo.dat
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git read-tree A B C..." without the "-m" (merge) option is a way to read
these trees on top of each other to get an overlay of them.
An ancient commit ee6566e (Rewrite read-tree, 2005-09-05) passed the
ADD_CACHE_SKIP_DFCHECK flag when calling add_index_entry() to add the
paths obtained from these trees to the index, but it is an incorrect use
of the flag. The flag is meant to be used by callers who know the
addition of the entry does not introduce a D/F conflict to the index in
order to avoid the overhead of checking.
This bug resulted in a bogus index that records both "x" and "x/z" as a
blob after reading three trees that have paths ("x"), ("x", "y"), and
("x/z", "y") respectively. 34110cd (Make 'unpack_trees()' have a separate
source and destination index, 2008-03-06) refactored the callsites of
add_index_entry() incorrectly and added more codepaths that use this flag
when it shouldn't be used.
Also, 0190457 (Move 'unpack_trees()' over to 'traverse_trees()' interface,
2008-03-05) introduced a bug to call add_index_entry() for the tree that
does not have the path in it, passing NULL as a cache entry. This caused
reading multiple trees, one of which has path "x" but another doesn't, to
segfault.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Traditionally, the lack of USE_NSEC meant "do not record nor use the
nanosecond resolution part of the file timestamps". To avoid problems on
filesystems that lose the ns part when the metadata is flushed to the disk
and then later read back in, disabling USE_NSEC has been a good idea in
general.
If you are on a filesystem without such an issue, it does not hurt to read
and store them in the cached stat data in the index entries even if your
git is compiled without USE_NSEC. The index left with such a version of
git can be read by git compiled with USE_NSEC and it can make use of the
nanosecond part to optimize the check to see if the path on the filesystem
hsa been modified since we last looked at.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we inside verify_uptodate() can already tell from the ce entry that
it is already uptodate by testing it with ce_uptodate(ce), there is no
need to call lstat(2) and ie_match_stat() afterwards.
And, reading from the commit log message from:
commit eadb583134
Author: Junio C Hamano <gitster@pobox.com>
Date: Fri Jan 18 23:45:24 2008 -0800
Avoid running lstat(2) on the same cache entry.
this also seems to be correct usage of the ce_uptodate() macro
introduced by that patch.
This will avoid lots of lstat(2) calls in some cases, for example
by running the 'git checkout' command.
Signed-off-by: Kjetil Barvik <barvik@broadpark.no>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since the filesystem ext4 is now defined as stable in Linux v2.6.28,
and ext4 supports nanonsecond resolution timestamps natively, it is
time to make USE_NSEC work as expected.
This will make racy git situations less likely to happen. For 'git
checkout' this means it will be less likely that we have to open, read
the contents of the file into RAM, and check if file is really
modified or not. The result sould be a litle less used CPU time, less
pagefaults and a litle faster program, at least for 'git checkout'.
Since the number of possible racy git situations would increase when
disks gets faster, this patch would be more and more helpfull as times
go by. For a fast Solid State Disk, this patch should be helpfull.
Note that, when file operations starts to take less than 1 nanosecond,
one would again start to get more racy git situations.
For more info on racy git, see Documentation/technical/racy-git.txt
For more info on ext4, see http://kernelnewbies.org/Ext4
Signed-off-by: Kjetil Barvik <barvik@broadpark.no>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Below is oprofile output from GIT command 'git chekcout -q my-v2.6.25'
(move from tag v2.6.27 to tag v2.6.25 of the Linux kernel):
CPU: Core 2, speed 1999.95 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit
mask of 0x00 (Unhalted core cycles) count 20000
Counted INST_RETIRED_ANY_P events (number of instructions retired) with a
unit mask of 0x00 (No unit mask) count 20000
CPU_CLK_UNHALT...|INST_RETIRED:2...|
samples| %| samples| %|
------------------------------------
409247 100.000 342878 100.000 git
CPU_CLK_UNHALT...|INST_RETIRED:2...|
samples| %| samples| %|
------------------------------------
260476 63.6476 257843 75.1996 libz.so.1.2.3
100876 24.6492 64378 18.7758 kernel-2.6.28.4_2.vmlinux
30850 7.5382 7874 2.2964 libc-2.9.so
14775 3.6103 8390 2.4469 git
2020 0.4936 4325 1.2614 libcrypto.so.0.9.8
191 0.0467 32 0.0093 libpthread-2.9.so
58 0.0142 36 0.0105 ld-2.9.so
1 2.4e-04 0 0 libldap-2.3.so.0.2.31
Detail list of the top 20 function entries (libz counted in one blob):
CPU_CLK_UNHALTED INST_RETIRED_ANY_P
samples % samples % image name symbol name
260476 63.6862 257843 75.2725 libz.so.1.2.3 /lib/libz.so.1.2.3
16587 4.0555 3636 1.0615 libc-2.9.so memcpy
7710 1.8851 277 0.0809 libc-2.9.so memmove
3679 0.8995 1108 0.3235 kernel-2.6.28.4_2.vmlinux d_validate
3546 0.8670 2607 0.7611 kernel-2.6.28.4_2.vmlinux __getblk
3174 0.7760 1813 0.5293 libc-2.9.so _int_malloc
2396 0.5858 3681 1.0746 kernel-2.6.28.4_2.vmlinux copy_to_user
2270 0.5550 2528 0.7380 kernel-2.6.28.4_2.vmlinux __link_path_walk
2205 0.5391 1797 0.5246 kernel-2.6.28.4_2.vmlinux ext4_mark_iloc_dirty
2103 0.5142 1203 0.3512 kernel-2.6.28.4_2.vmlinux find_first_zero_bit
2077 0.5078 997 0.2911 kernel-2.6.28.4_2.vmlinux do_get_write_access
2070 0.5061 514 0.1501 git cache_name_compare
2043 0.4995 1501 0.4382 kernel-2.6.28.4_2.vmlinux rcu_irq_exit
2022 0.4944 1732 0.5056 kernel-2.6.28.4_2.vmlinux __ext4_get_inode_loc
2020 0.4939 4325 1.2626 libcrypto.so.0.9.8 /usr/lib/libcrypto.so.0.9.8
1965 0.4804 1384 0.4040 git patch_delta
1708 0.4176 984 0.2873 kernel-2.6.28.4_2.vmlinux rcu_sched_grace_period
1682 0.4112 727 0.2122 kernel-2.6.28.4_2.vmlinux sysfs_slab_alias
1659 0.4056 290 0.0847 git find_pack_entry_one
1480 0.3619 1307 0.3816 kernel-2.6.28.4_2.vmlinux ext4_writepage_trans_blocks
Notice the memmove line, where the CPU did 7710 / 277 = 27.8 cycles
per instruction, and compared to the total cycles spent inside the
source code of GIT for this command, all the memmove() calls
translates to (7710 * 100) / 14775 = 52.2% of this.
Retesting with a GIT program compiled for gcov usage, I found out that
the memmove() calls came from remove_index_entry_at() in read-cache.c,
where we have:
memmove(istate->cache + pos,
istate->cache + pos + 1,
(istate->cache_nr - pos) * sizeof(struct cache_entry *));
remove_index_entry_at() is called 4902 times from check_updates() in
unpack-trees.c, and each time called we move each cache_entry pointers
(from the removed one) one step to the left.
Since we have 28828 entries in the cache this time, and if we on
average move half of them each time, we in total move approximately
4902 * 0.5 * 28828 * 4 = 282 629 712 bytes, or twice this amount if
each pointer is 8 bytes (64 bit).
OK, is seems that the function check_updates() is called 28 times, so
the estimated guess above had been more correct if check_updates() had
been called only once, but the point is: we get lots of bytes moved.
To fix this, and use an O(N) algorithm instead, where N is the number
of cache_entries, we delete/remove all entries in one loop through all
entries.
From a retest, the new remove_marked_cache_entries() from the patch
below, ended up with the following output line from oprofile:
46 0.0105 15 0.0041 git remove_marked_cache_entries
If we can trust the numbers from oprofile in this case, we saved
approximately ((7710 - 46) * 20000) / (2 * 1000 * 1000 * 1000) = 0.077
seconds CPU time with this fix for this particular test. And notice
that now the CPU did only 46 / 15 = 3.1 cycles/instruction.
Signed-off-by: Kjetil Barvik <barvik@broadpark.no>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently inside unlink_entry() if we get a successful removal of one
file with unlink(), we try to remove the leading directories each and
every time. So if one directory containing 200 files is moved to an
other location we get 199 failed calls to rmdir() and 1 successful
call.
To fix this and avoid some unnecessary calls to rmdir(), we schedule
each directory for removal and wait much longer before we do the real
call to rmdir().
Since the unlink_entry() function is called with alphabetically sorted
names, this new function end up being very effective to avoid
unnecessary calls to rmdir(). In some cases over 95% of all calls to
rmdir() is removed with this patch.
Signed-off-by: Kjetil Barvik <barvik@broadpark.no>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Swap function argument pair (length, string) into (string, length) to
conform with the commonly used order inside the GIT source code.
Also, add a note about this fact into the coding guidelines.
Signed-off-by: Kjetil Barvik <barvik@broadpark.no>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The parameter n of unpack_callback() can have a value of up to
MAX_UNPACK_TREES. The check at the top of unpack_trees() (its only
(indirect) caller) makes sure it cannot exceed this limit.
unpack_callback() passes it and the array src to unpack_nondirectories(),
which has this loop:
for (i = 0; i < n; i++) {
/* ... */
src[i + o->merge] = o->df_conflict_entry;
o->merge can be 0 or 1, so unpack_nondirectories() potentially accesses
the array src at index MAX_UNPACK_TREES. This patch makes it big enough.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* kb/lstat-cache:
lstat_cache(): introduce clear_lstat_cache() function
lstat_cache(): introduce invalidate_lstat_cache() function
lstat_cache(): introduce has_dirs_only_path() function
lstat_cache(): introduce has_symlink_or_noent_leading_path() function
lstat_cache(): more cache effective symlink/directory detection
In some cases, especially inside the unpack-trees.c file, and inside
the verify_absent() function, we can avoid some unnecessary calls to
lstat(), if the lstat_cache() function can also be told to keep track
of non-existing directories.
So we update the lstat_cache() function to handle this new fact,
introduce a new wrapper function, and the result is that we save lots
of lstat() calls for a removed directory which previously contained
lots of files, when we call this new wrapper of lstat_cache() instead
of the old one.
We do similar changes inside the unlink_entry() function, since if we
can already say that the leading directory component of a pathname
does not exist, it is not necessary to try to remove a pathname below
it!
Thanks to Junio C Hamano, Linus Torvalds and Rene Scharfe for valuable
comments to this patch!
Signed-off-by: Kjetil Barvik <barvik@broadpark.no>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since the only caller, verify_absent, relies on the fact that o->pos
points to the next index entry anyways, there is no need to recompute
its position.
Furthermore, if a nondirectory entry were found, this would return too
early, because there could still be an untracked directory in the way.
This is currently not a problem, because verify_absent is only called
if the index does not have this entry.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 0cf73755 (unpack-trees.c: assume submodules are clean during
check-out) changed an argument to verify_absent from 'path' to 'ce',
which is however shadowed by a local variable of the same name.
The bug triggers if verify_absent is used on a tree entry, for which
the index contains one or more subsequent directories of the same
length. The affected subdirectories are removed from the index. The
testcase included in this commit bisects to 55218834 (checkout: do not
lose staged removal), which reveals the bug in this case, but is
otherwise unrelated.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 203a2fe1 (Allow callers of unpack_trees() to handle failure)
changed the "die on error" behavior to "return failure code".
verify_absent did not handle errors returned by
verify_clean_subdirectory, however.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These were found using gcc 4.3.2-1ubuntu11 with the warning:
warning: format not a string literal and no format arguments
Incorporated suggestions from Brandon Casey <casey@nrlssc.navy.mil>.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most cache_entry structs are allocated by using the
cache_entry_size macro, which rounds the size of the struct
up to the nearest multiple of 8 bytes (presumably to avoid
memory fragmentation).
There is one exception: the special "conflict entry" is
allocated with an empty name, and so is explicitly given
just one extra byte to hold the NUL.
However, later code doesn't realize that this particular
struct has been allocated differently, and happily tries
reading and copying it based on the ce_size macro, which
assumes the 8-byte alignment.
This can lead to reading uninitalized data, though since
that data is simply padding, there shouldn't be any problem
as a result. Still, it makes sense to hold the padding
assumption so as not to surprise later maintainers.
This fixes valgrind errors in t1005, t3030, t4002, and
t4114.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The logic to checkout a different commit implements the safety to never
lose user's local changes. For example, switching from a commit to
another commit, when you have changed a path that is different between
them, need to merge your changes to the version from the switched-to
commit, which you may not necessarily be able to resolve easily. By
default, "git checkout" refused to switch branches, to give you a chance
to stash your local changes (or use "-m" to merge, accepting the risks of
getting conflicts).
This safety, however, had one deliberate hole since early June 2005. When
your local change was to remove a path (and optionally to stage that
removal), the command checked out the path from the switched-to commit
nevertheless.
This was to allow an initial checkout to happen smoothly (e.g. an initial
checkout is done by starting with an empty index and switching from the
commit at the HEAD to the same commit). We can tighten the rule slightly
to allow this special case to pass, without losing sight of removal
explicitly done by the user, by noticing if the index is truly empty when
the operation begins.
For historical background, see:
http://thread.gmane.org/gmane.comp.version-control.git/4641/focus=4646
This case is marked as *0* in the message, which both Linus and I said "it
feels somewhat wrong but otherwise we cannot start from an empty index".
Signed-off-by: Junio C Hamano <gitster@pobox.com>
unpack_trees() rebuilds the in-core index from scratch by allocating a new
structure and finishing it off by copying the built one to the final
index.
The resulting in-core index is Ok for most use, but read_cache() does not
recognize it as such. The function is meant to be no-op if you already
have loaded the index, until you call discard_cache().
This change the way read_cache() detects an already initialized in-core
index, by introducing an extra bit, and marks the handcrafted in-core
index as initialized, to avoid this problem.
A better fix in the longer term would be to change the read_cache() API so
that it will always discard and re-read from the on-disk index to avoid
confusion. But there are higher level API that have relied on the current
semantics, and they and their users all need to get converted, which is
outside the scope of 'maint' track.
An example of such a higher level API is write_cache_as_tree(), which is
used by git-write-tree as well as later Porcelains like git-merge, revert
and cherry-pick. In the longer term, we should remove read_cache() from
there and add one to cmd_write_tree(); other callers expect that the
in-core index they prepared is what gets written as a tree so no other
change is necessary for this particular codepath.
The original version of this patch marked the index by pointing an
otherwise wasted malloc'ed memory with o->result.alloc, but this version
uses Linus's idea to use a new "initialized" bit, which is conceptually
much cleaner.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of uniformly returning -1 on any error, this teaches
unpack_trees() to return -2 when the merge itself is Ok but worktree
refuses to get updated.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The plumbing output is sacred as it is an API. We _could_ change it if it
is broken in such a way that it cannot convey necessary information fully,
but we just do not _reword_ for the sake of rewording. If somebody does
not like it, s/he is complaining too late. S/he should have been here in
early May 2005 and make the language used by the API closer to what humans
read. S/he wasn't here. Too bad, and it is too late.
And people who complain should look at a bigger picture. Look at what was
suggested by one of them and think for five seconds:
$ git checkout mytopic
-fatal: Entry 'frotz' not uptodate. Cannot merge.
+fatal: Entry 'frotz' has local changes. Cannot merge.
If you do not see something wrong with this output, your brain has already
been rotten with use of git for too long a time. Nobody asked us to
"merge" but why are we talking about "Cannot merge"?
This patch introduces a mechanism to allow Porcelains to specify messages
that are different from the ones that is given by the underlying plumbing
implementation of read-tree, so that we can reword the message Porcelains give
without disrupting the output from the plumbing.
$ git-checkout pu
error: You have local changes to 'Makefile'; cannot switch branches.
There are other places that ask unpack_trees() to n-way merge, detect
issues and let it issue error message on its own, but I did this as a
demonstration and replaced only one message.
Yes I know about C99 structure initializers. I'd love to use them but we
try to be nice to compilers without it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is the base for making symlink detection in the middle fo a pathname
saner and (much) more efficient.
Under various loads, we want to verify that the full path leading up to a
filename is a real directory tree, and that when we successfully do an
'lstat()' on a filename, we don't get a false positive due to a symlink in
the middle of the path that git should have seen as a symlink, not as a
normal path component.
The 'has_symlink_leading_path()' function already did this, and cached
a single level of symlink information, but didn't cache the _lack_ of a
symlink, so the normal behaviour was actually the wrong way around, and we
ended up doing an 'lstat()' on each path component to check that it was a
real directory.
This caches the last detected full directory and symlink entries, and
speeds up especially deep directory structures a lot by avoiding to
lstat() all the directories leading up to each entry in the index.
[ This can - and should - probably be extended upon so that we eventually
never do a bare 'lstat()' on any path entries at *all* when checking the
index, but always check the full path carefully. Right now we do not
generally check the whole path for all our normal quick index
revalidation.
We should also make sure that we're careful about all the invalidation,
ie when we remove a link and replace it by a directory we should
invalidate the symlink cache if it matches (and vice versa for the
directory cache).
But regardless, the basic function needs to be sane to do that. The old
'has_symlink_leading_path()' was not capable enough - or indeed the code
readable enough - to really do that sanely. So I'm pushing this as not
just an optimization, but as a base for further work. ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is immaterial on sane filesystems, but if you have a broken (aka
case-insensitive) filesystem, and the objective is to remove the file
'abc' and replace it with the file 'Abc', then we must make sure to do
the removal first.
Otherwise, you'd first update the file 'Abc' - which would just
overwrite the file 'abc' due to the broken case-insensitive filesystem -
and then remove file 'abc' - which would now brokenly remove the just
updated file 'Abc' on that broken filesystem.
By doing removals first, this won't happen.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we find an unexpected file, see if that filename perhaps exists in a
case-insensitive way in the index, and whether the file matches that. If
so, ignore it as a known pre-existing file of a different name.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Right now nobody uses it, but "index_name_exists()" gets a flag so
you can enable it on a case-by-case basis.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
