The convert_to_sparse() method checks for the GIT_TEST_SPARSE_INDEX
environment variable or the "index.sparse" config setting before
converting the index to a sparse one. This is for ease of use since all
current consumers are preparing to compress the index before writing it
to disk. If these settings are not enabled, then convert_to_sparse()
silently returns without doing anything.
We will add a consumer in the next change that wants to use the sparse
index as an in-memory data structure, regardless of whether the on-disk
format should be sparse.
To that end, create the SPARSE_INDEX_MEMORY_ONLY flag that will skip
these config checks when enabled. All current consumers are modified to
pass '0' in the new 'flags' parameter.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Leak plugging.
* ah/plugleaks:
reset: clear_unpack_trees_porcelain to plug leak
builtin/rebase: fix options.strategy memory lifecycle
builtin/merge: free found_ref when done
builtin/mv: free or UNLEAK multiple pointers at end of cmd_mv
convert: release strbuf to avoid leak
read-cache: call diff_setup_done to avoid leak
ref-filter: also free head for ATOM_HEAD to avoid leak
diffcore-rename: move old_dir/new_dir definition to plug leak
builtin/for-each-repo: remove unnecessary argv copy to plug leak
builtin/submodule--helper: release unused strbuf to avoid leak
environment: move strbuf into block to plug leak
fmt-merge-msg: free newly allocated temporary strings when done
"git read-tree" had a codepath where blobs are fetched one-by-one
from the promisor remote, which has been corrected to fetch in bulk.
* jt/bulk-prefetch:
cache-tree: prefetch in partial clone read-tree
unpack-trees: refactor prefetching code
"git status" codepath learned to work with sparsely populated index
without hydrating it fully.
* ds/status-with-sparse-index:
t1092: document bad sparse-checkout behavior
fsmonitor: integrate with sparse index
wt-status: expand added sparse directory entries
status: use sparse-index throughout
status: skip sparse-checkout percentage with sparse-index
diff-lib: handle index diffs with sparse dirs
dir.c: accept a directory as part of cone-mode patterns
unpack-trees: unpack sparse directory entries
unpack-trees: rename unpack_nondirectories()
unpack-trees: compare sparse directories correctly
unpack-trees: preserve cache_bottom
t1092: add tests for status/add and sparse files
t1092: expand repository data shape
t1092: replace incorrect 'echo' with 'cat'
sparse-index: include EXTENDED flag when expanding
sparse-index: skip indexes with unmerged entries
repo_diff_setup() calls through to diff.c's static prep_parse_options(),
which in turn allocates a new array into diff_opts.parseopts.
diff_setup_done() is responsible for freeing that array, and has the
benefit of verifying diff_opts too - hence we add a call to
diff_setup_done() to avoid leaking parseopts.
Output from the leak as found while running t0090 with LSAN:
Direct leak of 7120 byte(s) in 1 object(s) allocated from:
#0 0x49a82d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0xa8bf89 in do_xmalloc wrapper.c:41:8
#2 0x7a7bae in prep_parse_options diff.c:5636:2
#3 0x7a7bae in repo_diff_setup diff.c:4611:2
#4 0x93716c in repo_index_has_changes read-cache.c:2518:3
#5 0x872233 in unclean merge-ort-wrappers.c:12:14
#6 0x872233 in merge_ort_recursive merge-ort-wrappers.c:53:6
#7 0x5d5b11 in try_merge_strategy builtin/merge.c:752:12
#8 0x5d0b6b in cmd_merge builtin/merge.c:1666:9
#9 0x4ce83e in run_builtin git.c:475:11
#10 0x4ccafe in handle_builtin git.c:729:3
#11 0x4cb01c in run_argv git.c:818:4
#12 0x4cb01c in cmd_main git.c:949:19
#13 0x6bdc2d in main common-main.c:52:11
#14 0x7f551eb51349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 7120 byte(s) leaked in 1 allocation(s)
Signed-off-by: Andrzej Hunt <andrzej@ahunt.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactor the prefetching code in unpack-trees.c into its own function,
because it will be used elsewhere in a subsequent commit.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By testing 'git -c core.fsmonitor= status -uno', we can check for the
simplest index operations that can be made sparse-aware. The necessary
implementation details are already integrated with sparse-checkout, so
modify command_requires_full_index to be zero for cmd_status().
In refresh_index(), we loop through the index entries to refresh their
stat() information. However, sparse directories have no stat()
information to populate. Ignore these entries.
This allows 'git status' to no longer expand a sparse index to a full
one. This is further tested by dropping the "-uno" option and adding an
untracked file into the worktree.
The performance test p2000-sparse-checkout-operations.sh demonstrates
these improvements:
Test HEAD~1 HEAD
-----------------------------------------------------------------------------
2000.2: git status (full-index-v3) 0.31(0.30+0.05) 0.31(0.29+0.06) +0.0%
2000.3: git status (full-index-v4) 0.31(0.29+0.07) 0.34(0.30+0.08) +9.7%
2000.4: git status (sparse-index-v3) 2.35(2.28+0.10) 0.04(0.04+0.05) -98.3%
2000.5: git status (sparse-index-v4) 2.35(2.24+0.15) 0.05(0.04+0.06) -97.9%
Note that since HEAD~1 was expanding the sparse index by parsing trees,
it was artificially slower than the full index case. Thus, the 98%
improvement is misleading, and instead we should celebrate the 0.34s to
0.05s improvement of 85%. This is more indicative of the peformance
gains we are expecting by using a sparse index.
Note: we are dropping the assignment of core.fsmonitor here. This is not
necessary for the test script as we are not altering the config any
other way. Correct integration with FS Monitor will be validated in
later changes.
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Linux users may benefit from additional information on how to
avoid ENOMEM from mmap despite the system having enough RAM to
accomodate them. We can't reliably unmap pack windows to work
around the issue since malloc and other library routines may
mmap without our knowledge.
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Don't guard the calls to the progress.c API with "if (progress)". The
API itself will check this. This doesn't change any behavior, but
makes this code consistent with the rest of the codebase.
See ae9af12287 (status: show progress bar if refreshing the index
takes too long, 2018-09-15) for the commit that added the pattern
we're changing here.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These methods were marked as MAYBE_UNUSED in the previous change to
avoid a complicated diff. Delete them entirely, since we now use the
hashfile API instead of this custom hashing code.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The do_write_index() method in read-cache.c has its own hashing logic
and buffering mechanism. Specifically, the ce_write() method was
introduced by 4990aadc (Speed up index file writing by chunking it
nicely, 2005-04-20) and similar mechanisms were introduced a few months
later in c38138cd (git-pack-objects: write the pack files with a SHA1
csum, 2005-06-26). Based on the timing, in the early days of the Git
codebase, I figured that these roughly equivalent code paths were never
unified only because it got lost in the shuffle. The hashfile API has
since been used extensively in other file formats, such as pack-indexes,
multi-pack-indexes, and commit-graphs. Therefore, it seems prudent to
unify the index writing code to use the same mechanism.
I discovered this disparity while trying to create a new index format
that uses the chunk-format API. That API uses a hashfile as its base, so
it is incompatible with the custom code in read-cache.c.
This rewrite is rather straightforward. It replaces all writes to the
temporary file with writes to the hashfile struct. This takes care of
many of the direct interactions with the_hash_algo.
There are still some git_hash_ctx uses remaining: the extension headers
are hashed for use in the End of Index Entries (EOIE) extension. This
use of the git_hash_ctx is left as-is. There are multiple reasons to not
use a hashfile here, including the fact that the data is not actually
writing to a file, just a hash computation. These hashes do not block
our adoption of the chunk-format API in a future change to the index, so
leave it as-is.
The internals of the algorithms are mostly identical. Previously, the
hashfile API used a smaller 8KB buffer instead of the 128KB buffer from
read-cache.c. The previous change already unified these sizes.
There is one subtle point: we do not pass the CSUM_FSYNC to the
finalize_hashfile() method, which differs from most consumers of the
hashfile API. The extra fsync() call indicated by this flag causes a
significant peformance degradation that is noticeable for quick
commands that write the index, such as "git add". Other consumers can
absorb this cost with their more complicated data structure
organization, and further writing structures such as pack-files and
commit-graphs is rarely in the critical path for common user
interactions.
Some static methods become orphaned in this diff, so I marked them as
MAYBE_UNUSED. The diff is much harder to read if they are deleted during
this change. Instead, they will be deleted in the following change.
In addition to the test suite passing, I computed indexes using the
previous binaries and the binaries compiled after this change, and found
the index data to be exactly equal. Finally, I did extensive performance
testing of "git update-index --force-write" on repos of various sizes,
including one with over 2 million paths at HEAD. These tests
demonstrated less than 1% difference in behavior. As expected, the
performance should be considered unchanged. The previous changes to
increase the hashfile buffer size from 8K to 128K ensured this change
would not create a peformance regression.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The final part of "parallel checkout".
* mt/parallel-checkout-part-3:
ci: run test round with parallel-checkout enabled
parallel-checkout: add tests related to .gitattributes
t0028: extract encoding helpers to lib-encoding.sh
parallel-checkout: add tests related to path collisions
parallel-checkout: add tests for basic operations
checkout-index: add parallel checkout support
builtin/checkout.c: complete parallel checkout support
make_transient_cache_entry(): optionally alloc from mem_pool
SHA-256 transition.
* bc/hash-transition-interop-part-1:
hex: print objects using the hash algorithm member
hex: default to the_hash_algo on zero algorithm value
builtin/pack-objects: avoid using struct object_id for pack hash
commit-graph: don't store file hashes as struct object_id
builtin/show-index: set the algorithm for object IDs
hash: provide per-algorithm null OIDs
hash: set, copy, and use algo field in struct object_id
builtin/pack-redundant: avoid casting buffers to struct object_id
Use the final_oid_fn to finalize hashing of object IDs
hash: add a function to finalize object IDs
http-push: set algorithm when reading object ID
Always use oidread to read into struct object_id
hash: add an algo member to struct object_id
"git add" and "git rm" learned not to touch those paths that are
outside of sparse checkout.
* mt/add-rm-in-sparse-checkout:
rm: honor sparse checkout patterns
add: warn when asked to update SKIP_WORKTREE entries
refresh_index(): add flag to ignore SKIP_WORKTREE entries
pathspec: allow to ignore SKIP_WORKTREE entries on index matching
add: make --chmod and --renormalize honor sparse checkouts
t3705: add tests for `git add` in sparse checkouts
add: include magic part of pathspec on --refresh error
Allow make_transient_cache_entry() to optionally receive a mem_pool
struct in which it should allocate the entry. This will be used in the
following patch, to store some transient entries which should persist
until parallel checkout finishes.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Builds on top of the sparse-index infrastructure to mark operations
that are not ready to mark with the sparse index, causing them to
fall back on fully-populated index that they always have worked with.
* ds/sparse-index-protections: (47 commits)
name-hash: use expand_to_path()
sparse-index: expand_to_path()
name-hash: don't add directories to name_hash
revision: ensure full index
resolve-undo: ensure full index
read-cache: ensure full index
pathspec: ensure full index
merge-recursive: ensure full index
entry: ensure full index
dir: ensure full index
update-index: ensure full index
stash: ensure full index
rm: ensure full index
merge-index: ensure full index
ls-files: ensure full index
grep: ensure full index
fsck: ensure full index
difftool: ensure full index
commit: ensure full index
checkout: ensure full index
...
The backslash character is not a valid part of a file name on Windows.
If, in Windows, Git attempts to write a file that has a backslash
character in the filename, it will be incorrectly interpreted as a
directory separator.
This caused CVE-2019-1354 in MinGW, as this behaviour can be manipulated
to cause the checkout to write to files it ought not write to, such as
adding code to the .git/hooks directory. This was fixed by e1d911dd4c
(mingw: disallow backslash characters in tree objects' file names,
2019-09-12). However, the vulnerability also exists in Cygwin: while
Cygwin mostly provides a POSIX-like path system, it will still interpret
a backslash as a directory separator.
To avoid this vulnerability, CVE-2021-29468, extend the previous fix to
also apply to Cygwin.
Similarly, extend the test case added by the previous version of the
commit. The test suite doesn't have an easy way to say "run this test
if in MinGW or Cygwin", so add a new test prerequisite that covers both.
As well as checking behaviour in the presence of paths containing
backslashes, the existing test also checks behaviour in the presence of
paths that differ only by the presence of a trailing ".". MinGW follows
normal Windows application behaviour and treats them as the same path,
but Cygwin more closely emulates *nix systems (at the expense of
compatibility with native Windows applications) and will create and
distinguish between such paths. Gate the relevant bit of that test
accordingly.
Reported-by: RyotaK <security@ryotak.me>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Adam Dinwoodie <adam@dinwoodie.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the future, we'll want oidread to automatically set the hash
algorithm member for an object ID we read into it, so ensure we use
oidread instead of hashcpy everywhere we're copying a hash value into a
struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before iterating over all cache entries, ensure that a sparse index is
expanded to a full index to avoid unexpected behavior.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Callers to index_name_pos() or index_name_stage_pos() have a specific
path in mind. If that happens to be a path with an ancestor being a
sparse-directory entry, it can lead to unexpected results.
In the case that we did not find the requested path, check to see if the
position _before_ the inserted position is a sparse directory entry that
matches the initial segment of the input path (including the directory
separator at the end of the directory name). If so, then expand the
index to be a full index and search again. This expansion will only
happen once per index read.
Future enhancements could be more careful to expand only the necessary
sparse directory entry, but then we would have a special "not fully
sparse, but also not fully expanded" mode that could affect writing the
index to file. Since this only occurs if a specific file is requested
outside of the sparse checkout definition, this is unlikely to be a
common situation.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Several methods specify that they take a 'struct index_state' pointer
with the 'const' qualifier because they intend to only query the data,
not change it. However, we will be introducing a step very low in the
method stack that might modify a sparse-index to become a full index in
the case that our queries venture inside a sparse-directory entry.
This change only removes the 'const' qualifiers that are necessary for
the following change which will actually modify the implementation of
index_name_stage_pos().
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
refresh_index() doesn't update SKIP_WORKTREE entries, but it still
matches them against the given pathspecs, marks the matches on the
seen[] array, check if unmerged, etc. In the following patch, one caller
will need refresh_index() to ignore SKIP_WORKTREE entries entirely, so
add a flag that implements this behavior.
While we are here, also realign the REFRESH_* flags and convert the hex
values to the more natural bit shift format, which makes it easier to
spot holes.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we have a full index, then we can convert it to a sparse index by
replacing directories outside of the sparse cone with sparse directory
entries. The convert_to_sparse() method does this, when the situation is
appropriate.
For now, we avoid converting the index to a sparse index if:
1. the index is split.
2. the index is already sparse.
3. sparse-checkout is disabled.
4. sparse-checkout does not use cone mode.
Finally, we currently limit the conversion to when the
GIT_TEST_SPARSE_INDEX environment variable is enabled. A mode using Git
config will be added in a later change.
The trickiest thing about this conversion is that we might not be able
to mark a directory as a sparse directory just because it is outside the
sparse cone. There might be unmerged files within that directory, so we
need to look for those. Also, if there is some strange reason why a file
is not marked with CE_SKIP_WORKTREE, then we should give up on
converting that directory. There is still hope that some of its
subdirectories might be able to convert to sparse, so we keep looking
deeper.
The conversion process is assisted by the cache-tree extension. This is
calculated from the full index if it does not already exist. We then
abandon the cache-tree as it no longer applies to the newly-sparse
index. Thus, this cache-tree will be recalculated in every
sparse-full-sparse round-trip until we integrate the cache-tree
extension with the sparse index.
Some Git commands use the index after writing it. For example, 'git add'
will update the index, then write it to disk, then read its entries to
report information. To keep the in-memory index in a full state after
writing, we re-expand it to a full one after the write. This is wasteful
for commands that only write the index and do not read from it again,
but that is only the case until we make those commands "sparse aware."
We can compare the behavior of the sparse-index in
t1092-sparse-checkout-compability.sh by using GIT_TEST_SPARSE_INDEX=1
when operating on the 'sparse-index' repo. We can also compare the two
sparse repos directly, such as comparing their indexes (when expanded to
full in the case of the 'sparse-index' repo). We also verify that the
index is actually populated with sparse directory entries.
The 'checkout and reset (mixed)' test is marked for failure when
comparing a sparse repo to a full repo, but we can compare the two
sparse-checkout cases directly to ensure that we are not changing the
behavior when using a sparse index.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The index format does not currently allow for sparse directory entries.
This violates some expectations that older versions of Git or
third-party tools might not understand. We need an indicator inside the
index file to warn these tools to not interact with a sparse index
unless they are aware of sparse directory entries.
Add a new _required_ index extension, 'sdir', that indicates that the
index may contain sparse directory entries. This allows us to continue
to use the differences in index formats 2, 3, and 4 before we create a
new index version 5 in a later change.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We will mark an in-memory index_state as having sparse directory entries
with the sparse_index bit. These currently cannot exist, but we will add
a mechanism for collapsing a full index to a sparse one in a later
change. That will happen at write time, so we must first allow parsing
the format before writing it.
Commands or methods that require a full index in order to operate can
call ensure_full_index() to expand that index in-memory. This requires
parsing trees using that index's repository.
Sparse directory entries have a specific 'ce_mode' value. The macro
S_ISSPARSEDIR(ce->ce_mode) can check if a cache_entry 'ce' has this type.
This ce_mode is not possible with the existing index formats, so we don't
also verify all properties of a sparse-directory entry, which are:
1. ce->ce_mode == 0040000
2. ce->flags & CE_SKIP_WORKTREE is true
3. ce->name[ce->namelen - 1] == '/' (ends in dir separator)
4. ce->oid references a tree object.
These are all semi-enforced in ensure_full_index() to some extent. Any
deviation will cause a warning at minimum or a failure in the worst
case.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
CALLOC_ARRAY() macro replaces many uses of xcalloc().
* rs/calloc-array:
cocci: allow xcalloc(1, size)
use CALLOC_ARRAY
git-compat-util.h: drop trailing semicolon from macro definition
The data structure used by fsmonitor interface was not properly
duplicated during an in-core merge, leading to use-after-free etc.
* js/fsmonitor-unpack-fix:
fsmonitor: do not forget to release the token in `discard_index()`
fsmonitor: fix memory corruption in some corner cases
In 56c6910028 (fsmonitor: change last update timestamp on the
index_state to opaque token, 2020-01-07), we forgot to adjust
`discard_index()` to release the "last-update" token: it is no longer a
64-bit number, but a free-form string that has been allocated.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead. It shortens the code and infers the
element size automatically.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Raise the buffer size used when writing the index file out from
(obviously too small) 8kB to (clearly sufficiently large) 128kB.
* ns/raise-write-index-buffer-size:
read-cache: make the index write buffer size 128K
Preliminary changes to fsmonitor integration.
* jh/fsmonitor-prework:
fsmonitor: refactor initialization of fsmonitor_last_update token
fsmonitor: allow all entries for a folder to be invalidated
fsmonitor: log FSMN token when reading and writing the index
fsmonitor: log invocation of FSMonitor hook to trace2
read-cache: log the number of scanned files to trace2
read-cache: log the number of lstat calls to trace2
preload-index: log the number of lstat calls to trace2
p7519: add trace logging during perf test
p7519: move watchman cleanup earlier in the test
p7519: fix watchman watch-list test on Windows
p7519: do not rely on "xargs -d" in test
Writing an index 8K at a time invokes the OS filesystem and caching code
very frequently, introducing noticeable overhead while writing large
indexes. When experimenting with different write buffer sizes on Windows
writing the Windows OS repo index (260MB), most of the benefit came by
bumping the index write buffer size to 64K. I picked 128K to ensure that
we're past the knee of the curve.
With this change, the time under do_write_index for an index with 3M
files goes from ~1.02s to ~0.72s.
Signed-off-by: Neeraj Singh <neerajsi@ntdev.microsoft.com>
Acked-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Report the number of files in the working directory that were read and
their hashes verified in `refresh_index()`.
FSMonitor improves the performance of commands like `git status` by
avoiding scanning the disk for changed files. Let's measure this.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Report the total number of calls made to lstat() inside of refresh_index().
FSMonitor improves the performance of commands like `git status` by
avoiding scanning the disk for changed files. This can be seen in
`refresh_index()`. Let's measure this.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar to the previous commits, try to avoid peeking into the `struct
lock_file`. We also have some `struct tempfile`s -- let's avoid looking
into those as well.
Note that `do_write_index()` takes a tempfile and that when we call it,
we either have a tempfile which we can easily hand down, or we have a
lock file, from which we need to somehow obtain the internal tempfile.
So we need to leave that one instance of peeking-into. Nevertheless,
this commit leaves us not relying on exactly how the path of the
tempfile / lock file is stored internally.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
44c7e1a7e0 (mem-pool: use more standard initialization and finalization,
2020-08-15) moved the allocation of the mem-pool structure to callers.
It also added an allocation to load_cache_entries_threaded(), but for an
unrelated mem-pool. Fix that by allocating the correct one instead --
the one that is initialized two lines later.
Reported-by: Sandor Bodo-Merle <sbodomerle@gmail.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A typical memory type, such as strbuf, hashmap, or string_list can be
stored on the stack or embedded within another structure. mem_pool
cannot be, because of how mem_pool_init() and mem_pool_discard() are
written. mem_pool_init() does essentially the following (simplified
for purposes of explanation here):
void mem_pool_init(struct mem_pool **pool...)
{
*pool = xcalloc(1, sizeof(*pool));
It seems weird to require that mem_pools can only be accessed through a
pointer. It also seems slightly dangerous: unlike strbuf_release() or
strbuf_reset() or string_list_clear(), all of which put the data
structure into a state where it can be re-used after the call,
mem_pool_discard(pool) will leave pool pointing at free'd memory.
read-cache (and split-index) are the only current users of mem_pools,
and they haven't fallen into a use-after-free mistake here, but it seems
likely to be problematic for future users especially since several of
the current callers of mem_pool_init() will only call it when the
mem_pool* is not already allocated (i.e. is NULL).
This type of mechanism also prevents finding synchronization
points where one can free existing memory and then resume more
operations. It would be natural at such points to run something like
mem_pool_discard(pool...);
and, if necessary,
mem_pool_init(&pool...);
and then carry on continuing to use the pool. However, this fails badly
if several objects had a copy of the value of pool from before these
commands; in such a case, those objects won't get the updated value of
pool that mem_pool_init() overwrites pool with and they'll all instead
be reading and writing from free'd memory.
Modify mem_pool_init()/mem_pool_discard() to behave more like
strbuf_init()/strbuf_release()
or
string_list_init()/string_list_clear()
In particular: (1) make mem_pool_init() just take a mem_pool* and have
it only worry about allocating struct mp_blocks, not the struct mem_pool
itself, (2) make mem_pool_discard() free the memory that the pool was
responsible for, but leave it in a state where it can be used to
allocate more memory afterward (without the need to call mem_pool_init()
again).
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
has_dir_name() has some optimizations for the case where entries are
added to an index in the correct order. They kick in if the new entry
sorts after the last one. One of them exits early if the last entry has
a longer name than the directory of the new entry. Here's its comment:
/*
* The directory prefix lines up with part of
* a longer file or directory name, but sorts
* after it, so this sub-directory cannot
* collide with a file.
*
* last: xxx/yy-file (because '-' sorts before '/')
* this: xxx/yy/abc
*/
However, a file named xxx/yy would be sorted before xxx/yy-file because
'-' sorts after NUL, so the length check against the last entry is not
sufficient to rule out a collision. Remove it.
Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Suggested-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Further tweak to a "no backslash in indexed paths" for Windows port
we applied earlier.
* js/mingw-loosen-overstrict-tree-entry-checks:
mingw: safeguard better against backslashes in file names
In 224c7d70fa (mingw: only test index entries for backslashes, not tree
entries, 2019-12-31), we relaxed the check for backslashes in tree
entries to check only index entries.
However, the code change was incorrect: it was added to
`add_index_entry_with_check()`, not to `add_index_entry()`, so under
certain circumstances it was possible to side-step the protection.
Besides, the description of that commit purported that all index entries
would be checked when in fact they were only checked when being added to
the index (there are code paths that do not do that, constructing
"transient" index entries).
In any case, it was pointed out in one insightful review at
https://github.com/git-for-windows/git/pull/2437#issuecomment-566771835
that it would be a much better idea to teach `verify_path()` to perform
the check for a backslash. This is safer, even if it comes with two
notable drawbacks:
- `verify_path()` cannot say _what_ is wrong with the path, therefore
the user will no longer be told that there was a backslash in the
path, only that the path was invalid.
- The `git apply` command also calls the `verify_path()` function, and
might have been able to handle Windows-style paths (i.e. with
backslashes instead of forward slashes). This will no longer be
possible unless the user (temporarily) sets `core.protectNTFS=false`.
Note that `git add <windows-path>` will _still_ work because
`normalize_path_copy_len()` will convert the backslashes to forward
slashes before hitting the code path that creates an index entry.
The clear advantage is that `verify_path()`'s purpose is to check the
validity of the file name, therefore we naturally tap into all the code
paths that need safeguarding, also implicitly into future code paths.
The benefits of that approach outweigh the downsides, so let's move the
check from `add_index_entry_with_check()` to `verify_path()`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An earlier update to Git for Windows declared that a tree object is
invalid if it has a path component with backslash in it, which was
overly strict, which has been corrected. The only protection the
Windows users need is to prevent such path (or any path that their
filesystem cannot check out) from entering the index.
* js/mingw-loosen-overstrict-tree-entry-checks:
mingw: only test index entries for backslashes, not tree entries
During a clone of a repository that contained a file with a backslash in
its name in the past, as of v2.24.1(2), Git for Windows prints errors
like this:
error: filename in tree entry contains backslash: '\'
The idea is to prevent Git from even trying to write files with
backslashes in their file names: while these characters are valid in
file names on other platforms, on Windows it is interpreted as directory
separator (which would obviously lead to ambiguities, e.g. when there is
a file `a\b` and there is also a file `a/b`).
Arguably, this is the wrong layer for that error: As long as the user
never checks out the files whose names contain backslashes, there should
not be any problem in the first place.
So let's loosen the requirements: we now leave tree entries with
backslashes in their file names alone, but we do require any entries
that are added to the Git index to contain no backslashes on Windows.
Note: just as before, the check is guarded by `core.protectNTFS` (to
allow overriding the check by toggling that config setting), and it
is _only_ performed on Windows, as the backslash is not a directory
separator elsewhere, even when writing to NTFS-formatted volumes.
An alternative approach would be to try to prevent creating files with
backslashes in their file names. However, that comes with its own set of
problems. For example, `git config -f C:\ProgramData\Git\config ...` is
a very valid way to specify a custom config location, and we obviously
do _not_ want to prevent that. Therefore, the approach chosen in this
patch would appear to be better.
This addresses https://github.com/git-for-windows/git/issues/2435
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint-2.23: (44 commits)
Git 2.23.1
Git 2.22.2
Git 2.21.1
mingw: sh arguments need quoting in more circumstances
mingw: fix quoting of empty arguments for `sh`
mingw: use MSYS2 quoting even when spawning shell scripts
mingw: detect when MSYS2's sh is to be spawned more robustly
t7415: drop v2.20.x-specific work-around
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
...
* maint-2.22: (43 commits)
Git 2.22.2
Git 2.21.1
mingw: sh arguments need quoting in more circumstances
mingw: fix quoting of empty arguments for `sh`
mingw: use MSYS2 quoting even when spawning shell scripts
mingw: detect when MSYS2's sh is to be spawned more robustly
t7415: drop v2.20.x-specific work-around
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
...
* maint-2.21: (42 commits)
Git 2.21.1
mingw: sh arguments need quoting in more circumstances
mingw: fix quoting of empty arguments for `sh`
mingw: use MSYS2 quoting even when spawning shell scripts
mingw: detect when MSYS2's sh is to be spawned more robustly
t7415: drop v2.20.x-specific work-around
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
...
* maint-2.20: (36 commits)
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
...
