threads / patch / 58236

patchmerge-ort: clean up after failed merge

Subject: [PATCH] merge-ort: clean up after failed merge

## tl;dr

7 messages between Jul 29, 2022 and Jul 31, 2022. Diffs are folded; open one to read it.

replies: 6people: 3as markdown or json

Johannes Schindelin via GitGitGadget· Jul 29, 2022, 08:52 UTC · lore

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

In 9fefce68dc8 (merge-ort: basic outline for merge_switch_to_result(), 2020-12-13), we added functionality to lay down the result of a merge on disk. But we forgot to release the data structures in case `unpack_trees()` failed to run properly.

This was pointed out by the `linux-leaks` job in our CI runs.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
    merge-ort: clean up after failed merge
    
    I was investigating why seen's CI runs fail, and came up with this fix.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1307%2Fdscho%2Fmerge-ort-impl-leakfix-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1307/dscho/merge-ort-impl-leakfix-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1307

 merge-ort.c | 2 ++
 1 file changed, 2 insertions(+)

Show changes to merge-ort.c +2 −0

diff --git a/merge-ort.c b/merge-ort.c
index ee7fbe71404..61b9e90018b 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -1002,6 +1002,7 @@ void merge_switch_to_result(struct merge_options *opt,
 		if (checkout(opt, head, result->tree)) {
 			/* failure to function */
 			result->clean = -1;
+			merge_finalize(opt, result);
 			return;
 		}
 
@@ -1010,6 +1011,7 @@ void merge_switch_to_result(struct merge_options *opt,
 						    &opti->conflicted)) {
 			/* failure to function */
 			result->clean = -1;
+			merge_finalize(opt, result);
 			return;
 		}
 	}

base-commit: 9fefce68dc85d96781090f86c067d83f7c50b617

-- 
gitgitgadget

Elijah Newren· Jul 29, 2022, 15:31 UTC · re: Johannes Schindelin via GitGitGadget · lore

Re: [PATCH] merge-ort: clean up after failed merge

On Fri, Jul 29, 2022 at 1:52 AM Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com> wrote:

Show 47 quoted lines

>
> From: Johannes Schindelin <johannes.schindelin@gmx.de>
>
> In 9fefce68dc8 (merge-ort: basic outline for merge_switch_to_result(),
> 2020-12-13), we added functionality to lay down the result of a merge on
> disk. But we forgot to release the data structures in case
> `unpack_trees()` failed to run properly.
>
> This was pointed out by the `linux-leaks` job in our CI runs.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>     merge-ort: clean up after failed merge
>
>     I was investigating why seen's CI runs fail, and came up with this fix.
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1307%2Fdscho%2Fmerge-ort-impl-leakfix-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1307/dscho/merge-ort-impl-leakfix-v1
> Pull-Request: https://github.com/gitgitgadget/git/pull/1307
>
>  merge-ort.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/merge-ort.c b/merge-ort.c
> index ee7fbe71404..61b9e90018b 100644
> --- a/merge-ort.c
> +++ b/merge-ort.c
> @@ -1002,6 +1002,7 @@ void merge_switch_to_result(struct merge_options *opt,
>                 if (checkout(opt, head, result->tree)) {
>                         /* failure to function */
>                         result->clean = -1;
> +                       merge_finalize(opt, result);
>                         return;
>                 }
>
> @@ -1010,6 +1011,7 @@ void merge_switch_to_result(struct merge_options *opt,
>                                                     &opti->conflicted)) {
>                         /* failure to function */
>                         result->clean = -1;
> +                       merge_finalize(opt, result);
>                         return;
>                 }
>         }
>
> base-commit: 9fefce68dc85d96781090f86c067d83f7c50b617
> --
> gitgitgadget

Good catch. Can you rebase on to a slightly newer commit? I think we also need a trace2_region_leave() call in each block as well, which is only clear if you look at newer versions.

Johannes Schindelin via GitGitGadget· Jul 29, 2022, 17:12 UTC · re: Johannes Schindelin via GitGitGadget · lore

[PATCH v2 0/2] merge-ort: clean up after failed merge

I was investigating why seen's CI runs fail, and came up with this fix.

Changes since v1:

 * Rebased onto en/merge-ort-perf.
 * Now we're not only cleaning up the merge data structure, but also leaving
   the Trace2 region when returning early from merge_switch_to_result().

Johannes Schindelin (2):
  merge-ort: clean up after failed merge
  merge-ort: do leave Trace2 region even if checkout fails

 merge-ort.c | 5 +++++
 1 file changed, 5 insertions(+)

base-commit: 557ac0350d9efa1f59c708779ca3fb3aee121131
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1307%2Fdscho%2Fmerge-ort-impl-leakfix-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1307/dscho/merge-ort-impl-leakfix-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/1307

Range-diff vs v1:

 1:  128f77f7f34 ! 1:  082c7ffa41f merge-ort: clean up after failed merge
     @@ merge-ort.c: void merge_switch_to_result(struct merge_options *opt,
      +			merge_finalize(opt, result);
       			return;
       		}
     - 
     + 		trace2_region_leave("merge", "checkout", opt->repo);
      @@ merge-ort.c: void merge_switch_to_result(struct merge_options *opt,
       						    &opti->conflicted)) {
       			/* failure to function */
     @@ merge-ort.c: void merge_switch_to_result(struct merge_options *opt,
      +			merge_finalize(opt, result);
       			return;
       		}
     - 	}
     + 		trace2_region_leave("merge", "record_conflicted", opt->repo);
 -:  ----------- > 2:  d2e1af0f922 merge-ort: do leave Trace2 region even if checkout fails

-- 
gitgitgadget

Johannes Schindelin via GitGitGadget· Jul 29, 2022, 17:12 UTC · re: Johannes Schindelin via GitGitGadget · lore

[PATCH v2 1/2] merge-ort: clean up after failed merge

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

This was pointed out by the `linux-leaks` job in our CI runs.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 merge-ort.c | 2 ++
 1 file changed, 2 insertions(+)

Show changes to merge-ort.c +2 −0

diff --git a/merge-ort.c b/merge-ort.c
index 931b91438cf..e820e45a8e8 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -3157,6 +3157,7 @@ void merge_switch_to_result(struct merge_options *opt,
 		if (checkout(opt, head, result->tree)) {
 			/* failure to function */
 			result->clean = -1;
+			merge_finalize(opt, result);
 			return;
 		}
 		trace2_region_leave("merge", "checkout", opt->repo);
@@ -3167,6 +3168,7 @@ void merge_switch_to_result(struct merge_options *opt,
 						    &opti->conflicted)) {
 			/* failure to function */
 			result->clean = -1;
+			merge_finalize(opt, result);
 			return;
 		}
 		trace2_region_leave("merge", "record_conflicted", opt->repo);

-- 
gitgitgadget

Johannes Schindelin via GitGitGadget· Jul 29, 2022, 17:12 UTC · re: Johannes Schindelin via GitGitGadget · lore

[PATCH v2 2/2] merge-ort: do leave Trace2 region even if checkout fails

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

In 557ac0350d9 (merge-ort: begin performance work; instrument with trace2_region_* calls, 2021-01-23), we added Trace2 instrumentation, but in the error path that returns early, we forgot to tell Trace2 that we're leaving the region. Let's fix that.

Pointed-out-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 merge-ort.c | 3 +++
 1 file changed, 3 insertions(+)

Show changes to merge-ort.c +3 −0

diff --git a/merge-ort.c b/merge-ort.c
index e820e45a8e8..eb0296902ad 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -3158,6 +3158,7 @@ void merge_switch_to_result(struct merge_options *opt,
 			/* failure to function */
 			result->clean = -1;
 			merge_finalize(opt, result);
+			trace2_region_leave("merge", "checkout", opt->repo);
 			return;
 		}
 		trace2_region_leave("merge", "checkout", opt->repo);
@@ -3169,6 +3170,8 @@ void merge_switch_to_result(struct merge_options *opt,
 			/* failure to function */
 			result->clean = -1;
 			merge_finalize(opt, result);
+			trace2_region_leave("merge", "record_conflicted",
+					    opt->repo);
 			return;
 		}
 		trace2_region_leave("merge", "record_conflicted", opt->repo);

-- 
gitgitgadget

Elijah Newren· Jul 30, 2022, 00:50 UTC · re: Johannes Schindelin via GitGitGadget · lore

Re: [PATCH v2 0/2] merge-ort: clean up after failed merge

On Fri, Jul 29, 2022 at 10:12 AM Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com> wrote:

Show 15 quoted lines

>
> I was investigating why seen's CI runs fail, and came up with this fix.
>
> Changes since v1:
>
>  * Rebased onto en/merge-ort-perf.
>  * Now we're not only cleaning up the merge data structure, but also leaving
>    the Trace2 region when returning early from merge_switch_to_result().
>
> Johannes Schindelin (2):
>   merge-ort: clean up after failed merge
>   merge-ort: do leave Trace2 region even if checkout fails
>
>  merge-ort.c | 5 +++++
>  1 file changed, 5 insertions(+)

Thanks, series looks good to me:

Reviewed-by: Elijah Newren <newren@gmail.com>

Junio C Hamano· Jul 31, 2022, 18:44 UTC · re: Elijah Newren · lore

Re: [PATCH v2 0/2] merge-ort: clean up after failed merge

Elijah Newren <newren@gmail.com> writes:

Show 21 quoted lines

> On Fri, Jul 29, 2022 at 10:12 AM Johannes Schindelin via GitGitGadget
> <gitgitgadget@gmail.com> wrote:
>>
>> I was investigating why seen's CI runs fail, and came up with this fix.
>>
>> Changes since v1:
>>
>>  * Rebased onto en/merge-ort-perf.
>>  * Now we're not only cleaning up the merge data structure, but also leaving
>>    the Trace2 region when returning early from merge_switch_to_result().
>>
>> Johannes Schindelin (2):
>>   merge-ort: clean up after failed merge
>>   merge-ort: do leave Trace2 region even if checkout fails
>>
>>  merge-ort.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>
> Thanks, series looks good to me:
>
> Reviewed-by: Elijah Newren <newren@gmail.com>

Thanks, both.

The new "leave" calls immediately next to the existing ones that look identical appear duplicated, but correcting the logic first in an obvious way like the posted patch, leaving any clean-up to later, is a prudent thing to do.

Queued.