Some file monitors like watchman will use something other than a timestamp
to keep better track of what changes happen in between calls to query
the fsmonitor. The clockid in watchman is a string. Now that the index
is storing an opaque token for the last update the code needs to be
updated to pass that opaque token to a verion 2 of the fsmonitor hook.
Because there are repos that already have version 1 of the hook and we
want them to continue to work when git is updated, we need to handle
both version 1 and version 2 of the hook. In order to do that a
config value is being added core.fsmonitorHookVersion to force what
version of the hook should be used. When this is not set it will default
to -1 and then the code will attempt to call version 2 of the hook first.
If that fails it will fallback to trying version 1.
Signed-off-by: Kevin Willford <Kevin.Willford@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Users of oneway_merge() (like "reset --hard") learned to take
advantage of fsmonitor to avoid unnecessary lstat(2) calls.
* us/unpack-trees-fsmonitor:
unpack-trees: skip stat on fsmonitor-valid files
Docfix.
* en/doc-typofix:
Fix spelling errors in no-longer-updated-from-upstream modules
multimail: fix a few simple spelling errors
sha1dc: fix trivial comment spelling error
Fix spelling errors in test commands
Fix spelling errors in messages shown to users
Fix spelling errors in names of tests
Fix spelling errors in comments of testcases
Fix spelling errors in code comments
Fix spelling errors in documentation outside of Documentation/
Documentation: fix a bunch of typos, both old and new
The index might be aware that a file hasn't modified via fsmonitor, but
unpack-trees did not pay attention to it and checked via ie_match_stat
which can be inefficient on certain filesystems. This significantly slows
down commands that run oneway_merge, like checkout and reset --hard.
This patch makes oneway_merge check whether a file is considered
unchanged through fsmonitor and skips ie_match_stat on it. unpack-trees
also now correctly copies over fsmonitor validity state from the source
index. Finally, for correctness, we force a refresh of fsmonitor state in
tweak_fsmonitor.
After this change, commands like stash (that use reset --hard
internally) go from 8s or more to ~2s on a 250k file repository on a
mac.
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Kevin Willford <Kevin.Willford@microsoft.com>
Signed-off-by: Utsav Shah <utsav@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The comments for the staging/unstaging test did not accurately
describe the scenario being tested. It is not essential that
the test files being staged/unstaged appear at the end of the
index. All that is required is that the test files are not
flagged with CE_FSMONITOR_VALID and have a position in the
index greater than the number of entries in the index after
unstaging.
The comment for this test has been updated to be more
accurate with respect to the scenario that's being tested.
Signed-off-by: William Baker <William.Baker@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While doing some testing with fsmonitor enabled I found
that git commands would segfault after staging and
unstaging an untracked file. Looking at the crash it
appeared that fsmonitor_ewah_callback was attempting to
adjust bits beyond the bounds of the index cache.
Digging into how this could happen it became clear that
the fsmonitor extension must have been written with
more bits than there were entries in the index. The
root cause ended up being that fill_fsmonitor_bitmap was
populating fsmonitor_dirty with bits for all entries in
the index, even those that had been marked for removal.
To solve this problem fill_fsmonitor_bitmap has been
updated to skip entries with the the CE_REMOVE flag set.
With this change the bits written for the fsmonitor
extension will be consistent with the index entries
written by do_write_index. Additionally, BUG checks
have been added to detect if the number of bits in
fsmonitor_dirty should ever exceed the number of
entries in the index again.
Another option that was considered was moving the call
to fill_fsmonitor_bitmap closer to where the index is
written (and where the fsmonitor extension itself is
written). However, that did not work as the
fsmonitor_dirty bitmap must be filled before the index
is split during writing.
Signed-off-by: William Baker <William.Baker@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With this change, the `index_state` struct becomes the new home for the
flag that says whether the fsmonitor hook has been run, i.e. it is now
per-index.
It also gets re-set when the index is discarded, fixing the bug
demonstrated by the "test_expect_failure" test added in the preceding
commit. In that case fsmonitor-enabled Git would miss updates under
certain circumstances, see that preceding commit for details.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This one is tricky.
When `core.fsmonitor` is set, a `refresh_index()` will not perform a
full scan of files that might be modified, but will query the fsmonitor
and refresh only the ones that have been actually touched.
Due to implementation details, the fsmonitor is queried in
`refresh_cache_ent()`, but of course it only has to be queried once, so
we set a flag when we did that. But when the index was discarded, we did
not re-set that flag.
So far, this is only covered by our test suite when running with
GIT_TEST_FSMONITOR=$PWD/t7519/fsmonitor-all, and only due to the way the
built-in stash interacts with the recursive merge machinery.
Let's introduce a straight-forward regression test for this.
We simply extend the "read & discard index" loop in `test-tool
read-cache` to optionally refresh the index, report on a given file's
status, and then modify that file. Due to the bug described above, only
the first refresh will actually query the fsmonitor; subsequent loop
iterations will not.
This problem was reported by Ævar Arnfjörð Bjarmason.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some environment variables that control the runtime options of Git
used during tests are getting renamed for consistency.
* bp/rename-test-env-var:
t0000: do not get self-test disrupted by environment warnings
preload-index: update GIT_FORCE_PRELOAD_TEST support
read-cache: update TEST_GIT_INDEX_VERSION support
fsmonitor: update GIT_TEST_FSMONITOR support
preload-index: use git_env_bool() not getenv() for customization
t/README: correct spelling of "uncommon"
Rename GIT_FORCE_PRELOAD_TEST to GIT_TEST_PRELOAD_INDEX for consistency with
the other GIT_TEST_ special setups and properly document its use.
Add logic in t/test-lib.sh to give a warning when the old variable is set to
let people know they need to update their environment to use the new
variable.
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename GIT_FSMONITOR_TEST to GIT_TEST_FSMONITOR for consistency with the
other GIT_TEST_ special setups and properly document its use.
Add logic in t/test-lib.sh to give a warning when the old variable is set to
let people know they need to update their environment to use the new
variable.
Remove the outdated instructions on how to run the test suite utilizing
fsmonitor now that it is properly documented in t/README.
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
read_directory() code ignores all paths named ".git" even if it's not
a valid git repository. See treat_path() for details. Since ".git" is
basically invisible to read_directory(), when we are asked to
invalidate a path that contains ".git", we can safely ignore it
because the slow path would not consider it anyway.
This helps when fsmonitor is used and we have a real ".git" repo at
worktree top. Occasionally .git/index will be updated and if the
fsmonitor hook does not filter it, untracked cache is asked to
invalidate the path ".git/index".
Without this patch, we invalidate the root directory unncessarily,
which:
- makes read_directory() fall back to slow path for root directory
(slower)
- makes the index dirty (because UNTR extension is updated). Depending
on the index size, writing it down could also be slow.
A note about the new "safe_path" knob. Since this new check could be
relatively expensive, avoid it when we know it's not needed. If the
path comes from the index, it can't contain ".git". If it does
contain, we may be screwed up at many more levels, not just this one.
Noticed-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ba1b9cac ("fsmonitor: delay updating state until after split index
is merged", 2017-10-27) resolved the problem of the fsmonitor data
being applied to the non-base index when reading; however, a similar
problem exists when writing the index. Specifically, writing of the
fsmonitor extension happens only after the work to split the index
has been applied -- as such, the information in the index is only
for the non-"base" index, and thus the extension information
contains only partial data.
When saving, compute the ewah bitmap before the index is split, and
store it in the fsmonitor_dirty field, mirroring the behavior that
occurred during reading. fsmonitor_dirty is kept from being leaked by
being freed when the extension data is written -- which always happens
precisely once, no matter the split index configuration.
Signed-off-by: Alex Vandiver <alexmv@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test the ability to add/remove the fsmonitor index extension via
update-index.
Test that dirty files returned from the integration script are properly
represented in the index extension and verify that ls-files correctly
reports their state.
Test that ensure status results are correct when using the new fsmonitor
extension. Test untracked, modified, and new files by ensuring the
results are identical to when not using the extension.
Test that if the fsmonitor extension doesn't tell git about a change, it
doesn't discover it on its own. This ensures git is honoring the
extension and that we get the performance benefits desired.
Three test integration scripts are provided:
fsmonitor-all - marks all files as dirty
fsmonitor-none - marks no files as dirty
fsmonitor-watchman - integrates with Watchman with debug logging
To run tests in the test suite while utilizing fsmonitor:
First copy t/t7519/fsmonitor-all to a location in your path and then set
GIT_FORCE_PRELOAD_TEST=true and GIT_FSMONITOR_TEST=fsmonitor-all and run
your tests.
Note: currently when using the test script fsmonitor-watchman on
Windows, many tests fail due to a reported but not yet fixed bug in
Watchman where it holds on to handles for directories and files which
prevents the test directory from being cleaned up properly.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
