Repository navigation
mmap: use private mappings for read-only files - #7315
Merged
Merged
Conversation
0xferrous
force-pushed
the
fix/read-only-mmap-private
branch
from
July 18, 2026 08:04
c24e080 to
438cb8c
Compare
Member
|
Thanks! |
Member
One point; I don't see a new test. Were you intending to add one? Not sure that it's necessary, but if you wanted one then I don't want to merge until it's in place. |
Read-only mappings do not require shared semantics. Some filesystems, including virtiofs and GPFS, reject MAP_SHARED mappings with ENODEV while allowing MAP_PRIVATE mappings. Use GIT_MAP_PRIVATE for the read-only mapping helper and when reading pack headers. This also matches the behavior of native Git. Keep the writable Windows indexer mapping shared, since writes made through that mapping must reach the underlying file. Add a test that verifies the read-only mapping helper creates a private mapping. Refs libgit2#7136
0xferrous
force-pushed
the
fix/read-only-mmap-private
branch
from
July 18, 2026 08:37
438cb8c to
c6ba959
Compare
Contributor
Author
|
yeah, sorry i forgot to push |
Member
|
Thanks! |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Read-only mappings do not require shared semantics. Some filesystems, including virtiofs and GPFS, reject MAP_SHARED mappings with ENODEV while allowing MAP_PRIVATE mappings.
Use GIT_MAP_PRIVATE for the read-only mapping helper and when reading pack headers. This also matches the behavior of native Git.
Keep the writable Windows indexer mapping shared, since writes made through that mapping must reach the underlying file.
Add a test that verifies the read-only mapping helper creates a private
mapping.
Refs #7136