From c3442568112f920749645667a959965bcb88a474 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= Date: Thu, 26 Aug 2021 22:59:59 +0200 Subject: [PATCH 1/6] t1600-index: remove unnecessary redirection MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In a helper function in the 't1600-index.sh' test script the stderr of a 'git add' command is redirected to its stdout, but its stdout is not redirected anywhere. So apparently this redirection is unnecessary, remove it. Signed-off-by: SZEDER Gábor Acked-by: Derrick Stolee Signed-off-by: Junio C Hamano --- t/t1600-index.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/t/t1600-index.sh b/t/t1600-index.sh index c9b9e718b8..5d10cec67a 100755 --- a/t/t1600-index.sh +++ b/t/t1600-index.sh @@ -79,7 +79,7 @@ test_index_version () { else unset GIT_INDEX_VERSION fi && - git add a 2>&1 && + git add a && echo $EXPECTED_OUTPUT_VERSION >expect && test-tool index-version <.git/index >actual && test_cmp expect actual From bdfe1f0d691a14f187c2f74f3731457977a9759e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= Date: Thu, 26 Aug 2021 23:00:00 +0200 Subject: [PATCH 2/6] t1600-index: don't run git commands upstream of a pipe MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: SZEDER Gábor Acked-by: Derrick Stolee Signed-off-by: Junio C Hamano --- t/t1600-index.sh | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/t/t1600-index.sh b/t/t1600-index.sh index 5d10cec67a..aa88fc30ce 100755 --- a/t/t1600-index.sh +++ b/t/t1600-index.sh @@ -13,7 +13,8 @@ test_expect_success 'bogus GIT_INDEX_VERSION issues warning' ' rm -f .git/index && GIT_INDEX_VERSION=2bogus && export GIT_INDEX_VERSION && - git add a 2>&1 | sed "s/[0-9]//" >actual.err && + git add a 2>err && + sed "s/[0-9]//" err >actual.err && sed -e "s/ Z$/ /" <<-\EOF >expect.err && warning: GIT_INDEX_VERSION set, but the value is invalid. Using version Z @@ -27,7 +28,8 @@ test_expect_success 'out of bounds GIT_INDEX_VERSION issues warning' ' rm -f .git/index && GIT_INDEX_VERSION=1 && export GIT_INDEX_VERSION && - git add a 2>&1 | sed "s/[0-9]//" >actual.err && + git add a 2>err && + sed "s/[0-9]//" err >actual.err && sed -e "s/ Z$/ /" <<-\EOF >expect.err && warning: GIT_INDEX_VERSION set, but the value is invalid. Using version Z @@ -50,7 +52,8 @@ test_expect_success 'out of bounds index.version issues warning' ' sane_unset GIT_INDEX_VERSION && rm -f .git/index && git config --add index.version 1 && - git add a 2>&1 | sed "s/[0-9]//" >actual.err && + git add a 2>err && + sed "s/[0-9]//" err >actual.err && sed -e "s/ Z$/ /" <<-\EOF >expect.err && warning: index.version set, but the value is invalid. Using version Z From daad41c96dd125bf2a667b24c334edcaede3dae5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= Date: Thu, 26 Aug 2021 23:00:01 +0200 Subject: [PATCH 3/6] t1600-index: disable GIT_TEST_SPLIT_INDEX MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Tests in 't1600-index.sh' check that various bogus index version values are recognized and an appropriate warning message is issued. GIT_TEST_SPLIT_INDEX=1 is supposed to trigger index splitting randomly, and thus might interfere [1] with these tests: splitting the index means that two index files are written (the shared base index and the split '.git/index'), and the same warning message is then issued twice, failing these tests. Unset GIT_TEST_SPLIT_INDEX in this test script to avoid such interference. [1] There is no such interference at the moment, because, alas, GIT_TEST_SPLIT_INDEX=1 is broken and never split the index. There was no such interference in the past (before it broke) either, because the first index write with GIT_TEST_SPLIT_INDEX=1 never split the index, only the second write did. A subsequent commit fixing GIT_TEST_SPLIT_INDEX will have all the details on this. Signed-off-by: SZEDER Gábor Acked-by: Derrick Stolee Signed-off-by: Junio C Hamano --- t/t1600-index.sh | 2 ++ 1 file changed, 2 insertions(+) diff --git a/t/t1600-index.sh b/t/t1600-index.sh index aa88fc30ce..46329c488b 100755 --- a/t/t1600-index.sh +++ b/t/t1600-index.sh @@ -4,6 +4,8 @@ test_description='index file specific tests' . ./test-lib.sh +sane_unset GIT_TEST_SPLIT_INDEX + test_expect_success 'setup' ' echo 1 >a ' From 998330ac2e7c384d2f73c734177ca21f36c06e48 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= Date: Thu, 26 Aug 2021 23:00:02 +0200 Subject: [PATCH 4/6] read-cache: look for shared index files next to the index, too MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When reading a split index git always looks for its referenced shared base index in the gitdir of the current repository, even when reading an alternate index specified via GIT_INDEX_FILE, and even when that alternate index file is the "main" '.git/index' file of an other repository. However, if that split index and its referenced shared index files were written by a git command running entirely in that other repository, then, naturally, the shared index file is written to that other repository's gitdir. Consequently, a git command attempting to read that shared index file while running in a different repository won't be able find it and will error out. I'm not sure in what use case it is necessary to read the index of one repository by a git command running in a different repository, but it is certainly possible to do so, and in fact the test 'bare repository: check that --cached honors index' in 't0003-attributes.sh' does exactly that. If GIT_TEST_SPLIT_INDEX=1 were to split the index in just the right moment [1], then this test would indeed fail, because the referenced shared index file could not be found. Let's look for the referenced shared index file not only in the gitdir of the current directory, but, if the shared index is not there, right next to the split index as well. [1] We haven't seen this issue trigger a failure in t0003 yet, because: - While GIT_TEST_SPLIT_INDEX=1 is supposed to trigger index splitting randomly, the first index write has always been deterministic and it has never split the index. - That alternate index file in the other repository is written only once in the entire test script, so it's never split. However, the next patch will fix GIT_TEST_SPLIT_INDEX, and while doing so it will slightly change its behavior to always split the index already on the first index write, and t0003 would always fail without this patch. Signed-off-by: SZEDER Gábor Acked-by: Derrick Stolee Signed-off-by: Junio C Hamano --- read-cache.c | 14 +++++++++++++- t/t1700-split-index.sh | 23 +++++++++++++++++++++++ 2 files changed, 36 insertions(+), 1 deletion(-) diff --git a/read-cache.c b/read-cache.c index f5d4385c40..3bf9ed4d43 100644 --- a/read-cache.c +++ b/read-cache.c @@ -2391,9 +2391,21 @@ int read_index_from(struct index_state *istate, const char *path, base_path = xstrfmt("%s/sharedindex.%s", gitdir, base_oid_hex); trace2_region_enter_printf("index", "shared/do_read_index", the_repository, "%s", base_path); - ret = do_read_index(split_index->base, base_path, 1); + ret = do_read_index(split_index->base, base_path, 0); trace2_region_leave_printf("index", "shared/do_read_index", the_repository, "%s", base_path); + if (!ret) { + char *path_copy = xstrdup(path); + const char *base_path2 = xstrfmt("%s/sharedindex.%s", + dirname(path_copy), + base_oid_hex); + free(path_copy); + trace2_region_enter_printf("index", "shared/do_read_index", + the_repository, "%s", base_path2); + ret = do_read_index(split_index->base, base_path2, 1); + trace2_region_leave_printf("index", "shared/do_read_index", + the_repository, "%s", base_path2); + } if (!oideq(&split_index->base_oid, &split_index->base->oid)) die(_("broken index, expect %s in %s, got %s"), base_oid_hex, base_path, diff --git a/t/t1700-split-index.sh b/t/t1700-split-index.sh index 986baa612e..e2aa0bd949 100755 --- a/t/t1700-split-index.sh +++ b/t/t1700-split-index.sh @@ -510,4 +510,27 @@ test_expect_success 'do not refresh null base index' ' ) ' +test_expect_success 'reading split index at alternate location' ' + git init reading-alternate-location && + ( + cd reading-alternate-location && + >file-in-alternate && + git update-index --split-index --add file-in-alternate + ) && + echo file-in-alternate >expect && + + # Should be able to find the shared index both right next to + # the specified split index file ... + GIT_INDEX_FILE=./reading-alternate-location/.git/index \ + git ls-files --cached >actual && + test_cmp expect actual && + + # ... and, for backwards compatibility, in the current GIT_DIR + # as well. + mv -v ./reading-alternate-location/.git/sharedindex.* .git && + GIT_INDEX_FILE=./reading-alternate-location/.git/index \ + git ls-files --cached >actual && + test_cmp expect actual +' + test_done From 61feddcdf2872b53d8ca5c84b4a1fcbce73ef86e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= Date: Thu, 26 Aug 2021 23:00:03 +0200 Subject: [PATCH 5/6] tests: disable GIT_TEST_SPLIT_INDEX for sparse index tests MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The sparse index and split index features are said to be currently incompatible [1], and consequently GIT_TEST_SPLIT_INDEX=1 might interfere with the test cases exercising the sparse index feature. Therefore GIT_TEST_SPLIT_INDEX is already explicitly disabled for the whole of 't1092-sparse-checkout-compatibility.sh'. There are, however, two other test cases exercising sparse index, namely 'sparse-index enabled and disabled' in 't1091-sparse-checkout-builtin.sh' and 'status succeeds with sparse index' in 't7519-status-fsmonitor.sh', and these two could fail with GIT_TEST_SPLIT_INDEX=1 as well [2]. Unset GIT_TEST_SPLIT_INDEX and disable the split index in these two test cases to avoid such interference. Note that this is the minimal change to merely avoid failures when these test cases are run with GIT_TEST_SPLIT_INDEX=1. Interestingly, though, without these changes the 'git sparse-checkout init --cone --sparse-index' commands still succeed even with split index, and set all the necessary configuration variables and create the initial '$GIT_DIR/info/sparse-checkout' file, but the test failures are caused by later sanity checks finding that the index is not in fact a sparse index. This indicates that 'git sparse-checkout init --sparse-index' lacks some error checking and its tests lack coverage related to split index, but fixing those issues is beyond the scope of this patch series. [1] https://public-inbox.org/git/48e9c3d6-407a-1843-2d91-22112410e3f8@gmail.com/ [2] Neither of these test cases fail at the moment, because GIT_TEST_SPLIT_INDEX=1 is broken and never splits the index, and it broke long before the sparse index feature was added. This patch series is about to fix GIT_TEST_SPLIT_INDEX, and then both test cases mentioned above would fail. (The diff is best viewed with '--ignore-all-space') Signed-off-by: SZEDER Gábor Acked-by: Derrick Stolee Signed-off-by: Junio C Hamano --- t/t1091-sparse-checkout-builtin.sh | 23 ++++++----- t/t7519-status-fsmonitor.sh | 64 ++++++++++++++++-------------- 2 files changed, 48 insertions(+), 39 deletions(-) diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh index 71236981e6..8675ad5154 100755 --- a/t/t1091-sparse-checkout-builtin.sh +++ b/t/t1091-sparse-checkout-builtin.sh @@ -206,16 +206,21 @@ test_expect_success 'sparse-checkout disable' ' ' test_expect_success 'sparse-index enabled and disabled' ' - git -C repo sparse-checkout init --cone --sparse-index && - test_cmp_config -C repo true index.sparse && - test-tool -C repo read-cache --table >cache && - grep " tree " cache && + ( + sane_unset GIT_TEST_SPLIT_INDEX && + git -C repo update-index --no-split-index && - git -C repo sparse-checkout disable && - test-tool -C repo read-cache --table >cache && - ! grep " tree " cache && - git -C repo config --list >config && - ! grep index.sparse config + git -C repo sparse-checkout init --cone --sparse-index && + test_cmp_config -C repo true index.sparse && + test-tool -C repo read-cache --table >cache && + grep " tree " cache && + + git -C repo sparse-checkout disable && + test-tool -C repo read-cache --table >cache && + ! grep " tree " cache && + git -C repo config --list >config && + ! grep index.sparse config + ) ' test_expect_success 'cone mode: init and set' ' diff --git a/t/t7519-status-fsmonitor.sh b/t/t7519-status-fsmonitor.sh index f1463197b9..f488d930df 100755 --- a/t/t7519-status-fsmonitor.sh +++ b/t/t7519-status-fsmonitor.sh @@ -399,41 +399,45 @@ check_sparse_index_behavior () { } test_expect_success 'status succeeds with sparse index' ' - git clone . full && - git clone --sparse . sparse && - git -C sparse sparse-checkout init --cone --sparse-index && - git -C sparse sparse-checkout set dir1 dir2 && + ( + sane_unset GIT_TEST_SPLIT_INDEX && - write_script .git/hooks/fsmonitor-test <<-\EOF && - printf "last_update_token\0" - EOF - git -C full config core.fsmonitor ../.git/hooks/fsmonitor-test && - git -C sparse config core.fsmonitor ../.git/hooks/fsmonitor-test && - check_sparse_index_behavior ! && + git clone . full && + git clone --sparse . sparse && + git -C sparse sparse-checkout init --cone --sparse-index && + git -C sparse sparse-checkout set dir1 dir2 && - write_script .git/hooks/fsmonitor-test <<-\EOF && - printf "last_update_token\0" - printf "dir1/modified\0" - EOF - check_sparse_index_behavior ! && + write_script .git/hooks/fsmonitor-test <<-\EOF && + printf "last_update_token\0" + EOF + git -C full config core.fsmonitor ../.git/hooks/fsmonitor-test && + git -C sparse config core.fsmonitor ../.git/hooks/fsmonitor-test && + check_sparse_index_behavior ! && - git -C sparse sparse-checkout add dir1a && + write_script .git/hooks/fsmonitor-test <<-\EOF && + printf "last_update_token\0" + printf "dir1/modified\0" + EOF + check_sparse_index_behavior ! && - for repo in full sparse - do - cp -r $repo/dir1 $repo/dir1a && - git -C $repo add dir1a && - git -C $repo commit -m "add dir1a" || return 1 - done && - git -C sparse sparse-checkout set dir1 dir2 && + git -C sparse sparse-checkout add dir1a && - # This one modifies outside the sparse-checkout definition - # and hence we expect to expand the sparse-index. - write_script .git/hooks/fsmonitor-test <<-\EOF && - printf "last_update_token\0" - printf "dir1a/modified\0" - EOF - check_sparse_index_behavior + for repo in full sparse + do + cp -r $repo/dir1 $repo/dir1a && + git -C $repo add dir1a && + git -C $repo commit -m "add dir1a" || return 1 + done && + git -C sparse sparse-checkout set dir1 dir2 && + + # This one modifies outside the sparse-checkout definition + # and hence we expect to expand the sparse-index. + write_script .git/hooks/fsmonitor-test <<-\EOF && + printf "last_update_token\0" + printf "dir1a/modified\0" + EOF + check_sparse_index_behavior + ) ' test_done From e8ffd034c8fa43efeeeee60483ca8690498e3085 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= Date: Thu, 26 Aug 2021 23:00:04 +0200 Subject: [PATCH 6/6] read-cache: fix GIT_TEST_SPLIT_INDEX MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Running tests with GIT_TEST_SPLIT_INDEX=1 is supposed to turn on the split index feature and trigger index splitting (mostly) randomly. Alas, this has been broken since 6e37c8ed3c (read-cache.c: fix writing "link" index ext with null base oid, 2019-02-13), and GIT_TEST_SPLIT_INDEX=1 hasn't triggered any index splitting since then. This patch makes GIT_TEST_SPLIT_INDEX work again, though it doesn't restore the pre-6e37c8ed3c behavior. To understand the bug, the fix, and the behavior change we first have to look at how GIT_TEST_SPLIT_INDEX used to work before 6e37c8ed3c: There are two places where we check the value of GIT_TEST_SPLIT_INDEX, and before 6e37c8ed3c they worked like this: 1) In the lower-level do_write_index(), where, if GIT_TEST_SPLIT_INDEX is enabled, we call init_split_index(). This call merely allocates and zero-initializes 'istate->split_index', but does nothing else (i.e. doesn't fill the base/shared index with cache entries, doesn't actually write a shared index file, etc.). Pertinent to this issue, the hash of the base index remains all zeroed out. 2) In the higher-level write_locked_index(), but only when 'istate->split_index' has already been initialized. Then, if GIT_TEST_SPLIT_INDEX is enabled, it randomly sets the flag that triggers index splitting later in this function. This randomness comes from the first byte of the hash of the base index via an 'if ((first_byte & 15) < 6)' condition. However, if 'istate->split_index' hasn't been initialized (i.e. it is still NULL), then write_locked_index() just calls do_write_locked_index(), which internally calls the above mentioned do_write_index(). This means that while GIT_TEST_SPLIT_INDEX=1 usually triggered index splitting randomly, the first two index writes were always deterministic (though I suspect this was unintentional): - The initial index write never splits the index. During the first index write write_locked_index() is called with 'istate->split_index' still uninitialized, so the check in 2) is not executed. It still calls do_write_index(), though, which then executes the check in 1). The resulting all zero base index hash then leads to the 'link' extension being written to '.git/index', though a shared index file is not written: $ rm .git/index $ GIT_TEST_SPLIT_INDEX=1 git update-index --add file $ test-tool dump-split-index .git/index own c6ef71168597caec8553c83d9d0048f1ef416170 base 0000000000000000000000000000000000000000 100644 d00491fd7e5bb6fa28c517a0bb32b8b506539d4d 0 file replacements: deletions: $ ls -l .git/sharedindex.* ls: cannot access '.git/sharedindex.*': No such file or directory - The second index write always splits the index. When the index written in the previous point is read, 'istate->split_index' is initialized because of the presence of the 'link' extension. So during the second write write_locked_index() does run the check in 2), and the first byte of the all zero base index hash always fulfills the randomness condition, which in turn always triggers the index splitting. - Subsequent index writes will find the 'link' extension with a real non-zero base index hash, so from then on the check in 2) is executed and the first byte of the base index hash is as random as it gets (coming from the SHA-1 of index data including timestamps and inodes...). All this worked until 6e37c8ed3c came along, and stopped writing the 'link' extension if the hash of the base index was all zero: $ rm .git/index $ GIT_TEST_SPLIT_INDEX=1 git update-index --add file $ test-tool dump-split-index .git/index own abbd6f6458d5dee73ae8e210ca15a68a390c6fd7 not a split index $ ls -l .git/sharedindex.* ls: cannot access '.git/sharedindex.*': No such file or directory So, since the first index write with GIT_TEST_SPLIT_INDEX=1 doesn't write a 'link' extension, in the second index write 'istate->split_index' remains uninitialized, and the check in 2) is not executed, and ultimately the index is never split. Fix this by modifying write_locked_index() to make sure to check GIT_TEST_SPLIT_INDEX even if 'istate->split_index' is still uninitialized, and initialize it if necessary. The check for GIT_TEST_SPLIT_INDEX and separate init_split_index() call in do_write_index() thus becomes unnecessary, so remove it. Furthermore, add a test to 't1700-split-index.sh' to make sure that GIT_TEST_SPLIT_INDEX=1 will keep working (though only check the index splitting on the first index write, because after that it will be random). Note that this change does not restore the pre-6e37c8ed3c behaviour, as it will deterministically split the index already on the first index write. Since GIT_TEST_SPLIT_INDEX is purely a developer aid, there is no backwards compatibility issue here. The new behaviour did trigger test failures in 't0003-attributes.sh' and 't1600-index.sh', though, which have been fixed in preparatory patches in this series. Signed-off-by: SZEDER Gábor Acked-by: Derrick Stolee Signed-off-by: Junio C Hamano --- read-cache.c | 23 ++++++++++++++--------- t/t1700-split-index.sh | 11 +++++++++++ 2 files changed, 25 insertions(+), 9 deletions(-) diff --git a/read-cache.c b/read-cache.c index 3bf9ed4d43..edcb2c5d97 100644 --- a/read-cache.c +++ b/read-cache.c @@ -2824,11 +2824,8 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, } } - if (!istate->version) { + if (!istate->version) istate->version = get_index_format_default(the_repository); - if (git_env_bool("GIT_TEST_SPLIT_INDEX", 0)) - init_split_index(istate); - } /* demote version 3 to version 2 when the latter suffices */ if (istate->version == 3 || istate->version == 2) @@ -3255,7 +3252,7 @@ static int too_many_not_shared_entries(struct index_state *istate) int write_locked_index(struct index_state *istate, struct lock_file *lock, unsigned flags) { - int new_shared_index, ret; + int new_shared_index, ret, test_split_index_env; struct split_index *si = istate->split_index; if (git_env_bool("GIT_TEST_CHECK_CACHE_TREE", 0)) @@ -3270,7 +3267,10 @@ int write_locked_index(struct index_state *istate, struct lock_file *lock, if (istate->fsmonitor_last_update) fill_fsmonitor_bitmap(istate); - if (!si || alternate_index_output || + test_split_index_env = git_env_bool("GIT_TEST_SPLIT_INDEX", 0); + + if ((!si && !test_split_index_env) || + alternate_index_output || (istate->cache_changed & ~EXTMASK)) { if (si) oidclr(&si->base_oid); @@ -3278,10 +3278,15 @@ int write_locked_index(struct index_state *istate, struct lock_file *lock, goto out; } - if (git_env_bool("GIT_TEST_SPLIT_INDEX", 0)) { - int v = si->base_oid.hash[0]; - if ((v & 15) < 6) + if (test_split_index_env) { + if (!si) { + si = init_split_index(istate); istate->cache_changed |= SPLIT_INDEX_ORDERED; + } else { + int v = si->base_oid.hash[0]; + if ((v & 15) < 6) + istate->cache_changed |= SPLIT_INDEX_ORDERED; + } } if (too_many_not_shared_entries(istate)) istate->cache_changed |= SPLIT_INDEX_ORDERED; diff --git a/t/t1700-split-index.sh b/t/t1700-split-index.sh index e2aa0bd949..decd2527ed 100755 --- a/t/t1700-split-index.sh +++ b/t/t1700-split-index.sh @@ -533,4 +533,15 @@ test_expect_success 'reading split index at alternate location' ' test_cmp expect actual ' +test_expect_success 'GIT_TEST_SPLIT_INDEX works' ' + git init git-test-split-index && + ( + cd git-test-split-index && + >file && + GIT_TEST_SPLIT_INDEX=1 git update-index --add file && + ls -l .git/sharedindex.* >actual && + test_line_count = 1 actual + ) +' + test_done