[PATCH] sequencer: release the ODB before spawning git commit

[PATCH] sequencer: release the ODB before spawning git commit

[Johannes Schindelin via GitGitGadget]

From: Johannes Schindelin <johannes.schindelin@gmx.de>

As of 4557f1add261 (rebase--helper: add a builtin helper for interactive
rebases, 2017-02-09), continuing an interactive rebase uses the builtin
sequencer, which spawns `git commit`.

The child may trigger auto-maintenance, which may need to replace files
for which the sequencer still holds resources. See
https://github.com/git-for-windows/git/issues/6315: on Windows, this
produces unlink retry prompts that cannot succeed while the sequencer
waits for the child.

Resources such as file handles or memory mappings must be released
before spawning a command that may run auto-maintenance, as established
by 28d04e1ec197 (run-command: offer to close the object store before
running, 2021-09-09).

Release the sequencer's ODB before spawning `git commit`. The regression
test uses the legacy-delete trick introduced by 69ed0e35a754 (mingw:
optionally use legacy (non-POSIX) delete semantics, 2026-05-07) to
trigger the failure on modern Windows.

Assisted-by: GPT-5.6 Sol
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
    sequencer: release the ODB before spawning git commit
    
    This fixes https://github.com/git-for-windows/git/issues/6315

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2198%2Fgit-for-windows%2Frebase-release-odb-before-commit-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2198/git-for-windows/rebase-release-odb-before-commit-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/2198

 sequencer.c                   |  1 +
 t/t3404-rebase-interactive.sh | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/sequencer.c b/sequencer.c
index 57855b0066..83952d96e3 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1127,6 +1127,7 @@ static int run_git_commit(const char *defmsg,
 	struct child_process cmd = CHILD_PROCESS_INIT;
 
 	cmd.git_cmd = 1;
+	cmd.odb_to_close = the_repository->objects;
 
 	if (is_rebase_i(opts) &&
 	    ((opts->committer_date_is_author_date && !opts->ignore_date) ||
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 58b3bb0c27..8f81c80fd4 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -65,6 +65,24 @@ test_expect_success 'setup' '
 	test_commit P fileP
 '
 
+test_expect_success MINGW 'rebase releases object database before committing' '
+	test_when_finished "rm -f .git/hooks/post-commit repacked packs" &&
+	git switch -C repack-rewrite primary &&
+	git repack -ad &&
+	write_script .git/hooks/post-commit <<-\EOF &&
+	git repack -ad &&
+	>repacked
+	EOF
+	(
+		set_fake_editor &&
+		FAKE_LINES="reword 1" GIT_TEST_LEGACY_DELETE=1 \
+			git -c core.commitGraph=false rebase -i HEAD^
+	) &&
+	test_path_is_file repacked &&
+	ls .git/objects/pack/*.pack >packs &&
+	test_line_count = 1 packs
+'
+
 # "exec" commands are run with the user shell by default, but this may
 # be non-POSIX. For example, if SHELL=zsh then ">file" doesn't work
 # to create a file. Unsetting SHELL avoids such non-portable behavior

base-commit: e9019fcafe0040228b8631c30f97ae1adb61bcdc
-- 
gitgitgadget

Re: [PATCH] sequencer: release the ODB before spawning git commit

[Junio C Hamano]

"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
>
> As of 4557f1add261 (rebase--helper: add a builtin helper for interactive
> rebases, 2017-02-09), continuing an interactive rebase uses the builtin
> sequencer, which spawns `git commit`.
>
> The child may trigger auto-maintenance, which may need to replace files
> for which the sequencer still holds resources. See
> https://github.com/git-for-windows/git/issues/6315: on Windows, this
> produces unlink retry prompts that cannot succeed while the sequencer
> waits for the child.
>
> Resources such as file handles or memory mappings must be released
> before spawning a command that may run auto-maintenance, as established
> by 28d04e1ec197 (run-command: offer to close the object store before
> running, 2021-09-09).

The sequencer is holding some resources, presumably because it needs
them to continue, and yet auto-maintenance wants to remove them?
Whether or not we face a Windows-specific limitation when removing
them, it is concerning to imagine what would happen if
auto-maintenance were allowed to do so and the sequencer then
resumed its work, only to find that the resources needed for its
operation were gone.

I think what the proposed commit log message lacks after 'must be
released' is 'and after auto-maintenance finishes and we regain
control, we will automatically reacquire these resources in a
refreshed state to proceed'.  Such an explanation would allay the
unease I expressed in the previous paragraph.

Perhaps issues/6315 talks about what exactly are held, but not
spelling it out in the log message is not helping readers.

> Release the sequencer's ODB before spawning `git commit`.

Makes sense.

> The regression
> test uses the legacy-delete trick introduced by 69ed0e35a754 (mingw:
> optionally use legacy (non-POSIX) delete semantics, 2026-05-07) to
> trigger the failure on modern Windows.

> diff --git a/sequencer.c b/sequencer.c
> index 57855b0066..83952d96e3 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -1127,6 +1127,7 @@ static int run_git_commit(const char *defmsg,
>  	struct child_process cmd = CHILD_PROCESS_INIT;
>  
>  	cmd.git_cmd = 1;
> +	cmd.odb_to_close = the_repository->objects;
>  
>  	if (is_rebase_i(opts) &&
>  	    ((opts->committer_date_is_author_date && !opts->ignore_date) ||
> diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
> index 58b3bb0c27..8f81c80fd4 100755
> --- a/t/t3404-rebase-interactive.sh
> +++ b/t/t3404-rebase-interactive.sh
> @@ -65,6 +65,24 @@ test_expect_success 'setup' '
>  	test_commit P fileP
>  '
>  
> +test_expect_success MINGW 'rebase releases object database before committing' '
> +	test_when_finished "rm -f .git/hooks/post-commit repacked packs" &&
> +	git switch -C repack-rewrite primary &&
> +	git repack -ad &&
> +	write_script .git/hooks/post-commit <<-\EOF &&
> +	git repack -ad &&
> +	>repacked
> +	EOF
> +	(
> +		set_fake_editor &&
> +		FAKE_LINES="reword 1" GIT_TEST_LEGACY_DELETE=1 \
> +			git -c core.commitGraph=false rebase -i HEAD^
> +	) &&
> +	test_path_is_file repacked &&
> +	ls .git/objects/pack/*.pack >packs &&
> +	test_line_count = 1 packs
> +'
> +
>  # "exec" commands are run with the user shell by default, but this may
>  # be non-POSIX. For example, if SHELL=zsh then ">file" doesn't work
>  # to create a file. Unsetting SHELL avoids such non-portable behavior
>
> base-commit: e9019fcafe0040228b8631c30f97ae1adb61bcdc

[PATCH v2] sequencer: release the ODB before spawning git commit

[Johannes Schindelin via GitGitGadget]

From: Johannes Schindelin <johannes.schindelin@gmx.de>

As of 4557f1add261 (rebase--helper: add a builtin helper for interactive
rebases, 2017-02-09), continuing an interactive rebase uses the builtin
sequencer, which spawns `git commit`.

The child may trigger auto-maintenance, which may need to replace files
for which the sequencer still holds resources. See
https://github.com/git-for-windows/git/issues/6315: on Windows, this
produces unlink retry prompts that cannot succeed while the sequencer
waits for the child.

Resources such as file handles or memory mappings must be released
before spawning a command that may run auto-maintenance, as established
by 28d04e1ec197 (run-command: offer to close the object store before
running, 2021-09-09): release the ODB file handles and memory mappings,
so that auto-gc can repack (potentially deleting existing packfiles in
the process); If the sequencer needs to access the ODB afterwards, it
will gracefully (re-)open the ODB.

Release the sequencer's ODB before spawning `git commit`. The regression
test uses the legacy-delete trick introduced by 69ed0e35a754 (mingw:
optionally use legacy (non-POSIX) delete semantics, 2026-05-07) to
trigger the failure on modern Windows.

Assisted-by: GPT-5.6 Sol
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
    sequencer: release the ODB before spawning git commit
    
    This fixes https://github.com/git-for-windows/git/issues/6315
    
    Changes since v1:
    
     * Clarify in the commit message what the strategy introduced in
       28d04e1ec197 (run-command: offer to close the object store before
       running, 2021-09-09) is all about.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2198%2Fgit-for-windows%2Frebase-release-odb-before-commit-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2198/git-for-windows/rebase-release-odb-before-commit-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/2198

Range-diff vs v1:

 1:  904d65e8cb ! 1:  039fd29039 sequencer: release the ODB before spawning git commit
     @@ Commit message
          Resources such as file handles or memory mappings must be released
          before spawning a command that may run auto-maintenance, as established
          by 28d04e1ec197 (run-command: offer to close the object store before
     -    running, 2021-09-09).
     +    running, 2021-09-09): release the ODB file handles and memory mappings,
     +    so that auto-gc can repack (potentially deleting existing packfiles in
     +    the process); If the sequencer needs to access the ODB afterwards, it
     +    will gracefully (re-)open the ODB.
      
          Release the sequencer's ODB before spawning `git commit`. The regression
          test uses the legacy-delete trick introduced by 69ed0e35a754 (mingw:


 sequencer.c                   |  1 +
 t/t3404-rebase-interactive.sh | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/sequencer.c b/sequencer.c
index 57855b0066..83952d96e3 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1127,6 +1127,7 @@ static int run_git_commit(const char *defmsg,
 	struct child_process cmd = CHILD_PROCESS_INIT;
 
 	cmd.git_cmd = 1;
+	cmd.odb_to_close = the_repository->objects;
 
 	if (is_rebase_i(opts) &&
 	    ((opts->committer_date_is_author_date && !opts->ignore_date) ||
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 58b3bb0c27..8f81c80fd4 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -65,6 +65,24 @@ test_expect_success 'setup' '
 	test_commit P fileP
 '
 
+test_expect_success MINGW 'rebase releases object database before committing' '
+	test_when_finished "rm -f .git/hooks/post-commit repacked packs" &&
+	git switch -C repack-rewrite primary &&
+	git repack -ad &&
+	write_script .git/hooks/post-commit <<-\EOF &&
+	git repack -ad &&
+	>repacked
+	EOF
+	(
+		set_fake_editor &&
+		FAKE_LINES="reword 1" GIT_TEST_LEGACY_DELETE=1 \
+			git -c core.commitGraph=false rebase -i HEAD^
+	) &&
+	test_path_is_file repacked &&
+	ls .git/objects/pack/*.pack >packs &&
+	test_line_count = 1 packs
+'
+
 # "exec" commands are run with the user shell by default, but this may
 # be non-POSIX. For example, if SHELL=zsh then ">file" doesn't work
 # to create a file. Unsetting SHELL avoids such non-portable behavior

base-commit: e9019fcafe0040228b8631c30f97ae1adb61bcdc
-- 
gitgitgadget

Re: [PATCH v2] sequencer: release the ODB before spawning git commit

[Junio C Hamano]

"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
>
> As of 4557f1add261 (rebase--helper: add a builtin helper for interactive
> rebases, 2017-02-09), continuing an interactive rebase uses the builtin
> sequencer, which spawns `git commit`.
>
> The child may trigger auto-maintenance, which may need to replace files
> for which the sequencer still holds resources. See
> https://github.com/git-for-windows/git/issues/6315: on Windows, this
> produces unlink retry prompts that cannot succeed while the sequencer
> waits for the child.
>
> Resources such as file handles or memory mappings must be released
> before spawning a command that may run auto-maintenance, as established
> by 28d04e1ec197 (run-command: offer to close the object store before
> running, 2021-09-09): release the ODB file handles and memory mappings,
> so that auto-gc can repack (potentially deleting existing packfiles in
> the process); If the sequencer needs to access the ODB afterwards, it
> will gracefully (re-)open the ODB.
>
> Release the sequencer's ODB before spawning `git commit`. The regression
> test uses the legacy-delete trick introduced by 69ed0e35a754 (mingw:
> optionally use legacy (non-POSIX) delete semantics, 2026-05-07) to
> trigger the failure on modern Windows.
>
> Assisted-by: GPT-5.6 Sol
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>     sequencer: release the ODB before spawning git commit
>     
>     This fixes https://github.com/git-for-windows/git/issues/6315

Thanks.  Let me mark the topic for 'next'.

> diff --git a/sequencer.c b/sequencer.c
> index 57855b0066..83952d96e3 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -1127,6 +1127,7 @@ static int run_git_commit(const char *defmsg,
>  	struct child_process cmd = CHILD_PROCESS_INIT;
>  
>  	cmd.git_cmd = 1;
> +	cmd.odb_to_close = the_repository->objects;
>  
>  	if (is_rebase_i(opts) &&
>  	    ((opts->committer_date_is_author_date && !opts->ignore_date) ||
> diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
> index 58b3bb0c27..8f81c80fd4 100755
> --- a/t/t3404-rebase-interactive.sh
> +++ b/t/t3404-rebase-interactive.sh
> @@ -65,6 +65,24 @@ test_expect_success 'setup' '
>  	test_commit P fileP
>  '
>  
> +test_expect_success MINGW 'rebase releases object database before committing' '
> +	test_when_finished "rm -f .git/hooks/post-commit repacked packs" &&
> +	git switch -C repack-rewrite primary &&
> +	git repack -ad &&
> +	write_script .git/hooks/post-commit <<-\EOF &&
> +	git repack -ad &&
> +	>repacked
> +	EOF
> +	(
> +		set_fake_editor &&
> +		FAKE_LINES="reword 1" GIT_TEST_LEGACY_DELETE=1 \
> +			git -c core.commitGraph=false rebase -i HEAD^
> +	) &&
> +	test_path_is_file repacked &&
> +	ls .git/objects/pack/*.pack >packs &&
> +	test_line_count = 1 packs
> +'
> +
>  # "exec" commands are run with the user shell by default, but this may
>  # be non-POSIX. For example, if SHELL=zsh then ">file" doesn't work
>  # to create a file. Unsetting SHELL avoids such non-portable behavior
>
> base-commit: e9019fcafe0040228b8631c30f97ae1adb61bcdc

Re: [PATCH v2] sequencer: release the ODB before spawning git commit

[Phillip Wood]

Hi Johannes

On 12/08/2026 10:54, Johannes Schindelin via GitGitGadget wrote:
> From: Johannes Schindelin <johannes.schindelin@gmx.de>
> 
> As of 4557f1add261 (rebase--helper: add a builtin helper for interactive
> rebases, 2017-02-09), continuing an interactive rebase uses the builtin
> sequencer, which spawns `git commit`.
> 
> The child may trigger auto-maintenance, which may need to replace files
> for which the sequencer still holds resources. See
> https://github.com/git-for-windows/git/issues/6315: on Windows, this
> produces unlink retry prompts that cannot succeed while the sequencer
> waits for the child.
> 
> Resources such as file handles or memory mappings must be released
> before spawning a command that may run auto-maintenance, as established
> by 28d04e1ec197 (run-command: offer to close the object store before
> running, 2021-09-09): release the ODB file handles and memory mappings,
> so that auto-gc can repack (potentially deleting existing packfiles in
> the process); If the sequencer needs to access the ODB afterwards, it
> will gracefully (re-)open the ODB.
> 
> Release the sequencer's ODB before spawning `git commit`. The regression
> test uses the legacy-delete trick introduced by 69ed0e35a754 (mingw:
> optionally use legacy (non-POSIX) delete semantics, 2026-05-07) to
> trigger the failure on modern Windows.

This looks fine as an immediate fix for the bug but I wonder if we 
should pass "-c gc.auto=false" when we fork "git commit" from the 
sequencer. We call run_auto_maintenance() at the end of the rebase and 
its not clear to me that repacking during the rebase is helpful. Another 
thought I had was whether we should automatically close the object 
database when forking another git command. I'm not sure how easy that is 
to implement but it would prevent future regressions and I assuming 
re-opening the object store is cheap compared to forking another git 
command.

Thanks

Phillip


> Assisted-by: GPT-5.6 Sol
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>      sequencer: release the ODB before spawning git commit
>      
>      This fixes https://github.com/git-for-windows/git/issues/6315
>      
>      Changes since v1:
>      
>       * Clarify in the commit message what the strategy introduced in
>         28d04e1ec197 (run-command: offer to close the object store before
>         running, 2021-09-09) is all about.
> 
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2198%2Fgit-for-windows%2Frebase-release-odb-before-commit-v2
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2198/git-for-windows/rebase-release-odb-before-commit-v2
> Pull-Request: https://github.com/gitgitgadget/git/pull/2198
> 
> Range-diff vs v1:
> 
>   1:  904d65e8cb ! 1:  039fd29039 sequencer: release the ODB before spawning git commit
>       @@ Commit message
>            Resources such as file handles or memory mappings must be released
>            before spawning a command that may run auto-maintenance, as established
>            by 28d04e1ec197 (run-command: offer to close the object store before
>       -    running, 2021-09-09).
>       +    running, 2021-09-09): release the ODB file handles and memory mappings,
>       +    so that auto-gc can repack (potentially deleting existing packfiles in
>       +    the process); If the sequencer needs to access the ODB afterwards, it
>       +    will gracefully (re-)open the ODB.
>        
>            Release the sequencer's ODB before spawning `git commit`. The regression
>            test uses the legacy-delete trick introduced by 69ed0e35a754 (mingw:
> 
> 
>   sequencer.c                   |  1 +
>   t/t3404-rebase-interactive.sh | 18 ++++++++++++++++++
>   2 files changed, 19 insertions(+)
> 
> diff --git a/sequencer.c b/sequencer.c
> index 57855b0066..83952d96e3 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -1127,6 +1127,7 @@ static int run_git_commit(const char *defmsg,
>   	struct child_process cmd = CHILD_PROCESS_INIT;
>   
>   	cmd.git_cmd = 1;
> +	cmd.odb_to_close = the_repository->objects;
>   
>   	if (is_rebase_i(opts) &&
>   	    ((opts->committer_date_is_author_date && !opts->ignore_date) ||
> diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
> index 58b3bb0c27..8f81c80fd4 100755
> --- a/t/t3404-rebase-interactive.sh
> +++ b/t/t3404-rebase-interactive.sh
> @@ -65,6 +65,24 @@ test_expect_success 'setup' '
>   	test_commit P fileP
>   '
>   
> +test_expect_success MINGW 'rebase releases object database before committing' '
> +	test_when_finished "rm -f .git/hooks/post-commit repacked packs" &&
> +	git switch -C repack-rewrite primary &&
> +	git repack -ad &&
> +	write_script .git/hooks/post-commit <<-\EOF &&
> +	git repack -ad &&
> +	>repacked
> +	EOF
> +	(
> +		set_fake_editor &&
> +		FAKE_LINES="reword 1" GIT_TEST_LEGACY_DELETE=1 \
> +			git -c core.commitGraph=false rebase -i HEAD^
> +	) &&
> +	test_path_is_file repacked &&
> +	ls .git/objects/pack/*.pack >packs &&
> +	test_line_count = 1 packs
> +'
> +
>   # "exec" commands are run with the user shell by default, but this may
>   # be non-POSIX. For example, if SHELL=zsh then ">file" doesn't work
>   # to create a file. Unsetting SHELL avoids such non-portable behavior
> 
> base-commit: e9019fcafe0040228b8631c30f97ae1adb61bcdc

Re: [PATCH v2] sequencer: release the ODB before spawning git commit

[Junio C Hamano]

Phillip Wood <phillip.wood123@gmail.com> writes:

> This looks fine as an immediate fix for the bug but I wonder if we 
> should pass "-c gc.auto=false" when we fork "git commit" from the 
> sequencer. We call run_auto_maintenance() at the end of the rebase and 
> its not clear to me that repacking during the rebase is helpful.

This is a bit amusing as I was reading old discussion the other day
around the constant 6700 [*] and saw it discused that because
"commit" triggers auto-gc, there was no point in doing so in
"rebase", which does series of "commit" invocations [*].  With small
projects and short rebases I tend to agree with you that gc at the
end of a rebase session should be plenty, but given the widespread
use of Git, itt may not apply to everybody.

> Another 
> thought I had was whether we should automatically close the object 
> database when forking another git command. I'm not sure how easy that is 
> to implement but it would prevent future regressions and I assuming 
> re-opening the object store is cheap compared to forking another git 
> command.

I think it is a great approach to study how feasible it is, as we
will not have to sprinkle fixes like the one proposed to many code
paths.  Thanks for raising it.


[References]

 * https://lore.kernel.org/git/?q=6700+d:..20071231
 * https://lore.kernel.org/git/20070906023934.GI18160@spearce.org/

Re: [PATCH v2] sequencer: release the ODB before spawning git commit

[Phillip Wood]

On 24/08/2026 15:36, Junio C Hamano wrote:
> Phillip Wood <phillip.wood123@gmail.com> writes:
> 
>> This looks fine as an immediate fix for the bug but I wonder if we
>> should pass "-c gc.auto=false" when we fork "git commit" from the
>> sequencer. We call run_auto_maintenance() at the end of the rebase and
>> its not clear to me that repacking during the rebase is helpful.
> 
> This is a bit amusing as I was reading old discussion the other day
> around the constant 6700 [*] and saw it discused that because
> "commit" triggers auto-gc, there was no point in doing so in
> "rebase", which does series of "commit" invocations [*].  With small
> projects and short rebases I tend to agree with you that gc at the
> end of a rebase session should be plenty, but given the widespread
> use of Git, itt may not apply to everybody.

That's a coincidence. These days we avoid running "git commit" for 
simple picks, but we do run it when rebasing a merge and I suspect large 
rebases probably include merges. So we will probably do trigger gc 
during large rebases even if there are no conflicts or commits being 
reworded (which I think are the only two other cases where we fork "git 
commit").

Thanks

Phillip

>> Another
>> thought I had was whether we should automatically close the object
>> database when forking another git command. I'm not sure how easy that is
>> to implement but it would prevent future regressions and I assuming
>> re-opening the object store is cheap compared to forking another git
>> command.
> 
> I think it is a great approach to study how feasible it is, as we
> will not have to sprinkle fixes like the one proposed to many code
> paths.  Thanks for raising it.
> 
> 
> [References]
> 
>   * https://lore.kernel.org/git/?q=6700+d:..20071231
>   * https://lore.kernel.org/git/20070906023934.GI18160@spearce.org/