[2/3] Proper path resolution: add readlinkat functionality #2264
Conversation
This file contains 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
This commit adds the `openat` functionality to `sys.FS`. On UNIX-like platforms, this is done with the `openat(2)` syscall. On Windows, this is done with [`NtCreateFile`][1]. This is the first in a series of commit that overhauls how paths are resolved. The wasi-filesystem spec now [describes][2] a path resolution implementation that uses `openat`. [1]: https://learn.microsoft.com/en-us/windows/win32/api/winternl/nf-winternl-ntcreatefile [2]: https://github.com/WebAssembly/wasi-filesystem/blob/main/path-resolution.md Signed-off-by: Yage Hu <[email protected]>
Signed-off-by: Yage Hu <[email protected]>
Signed-off-by: Yage Hu <[email protected]>
Signed-off-by: Yage Hu <[email protected]>
Signed-off-by: Yage Hu <[email protected]>
Signed-off-by: Yage Hu <[email protected]>
Signed-off-by: Yage Hu <[email protected]>
This commit adds the `ReadLinkAt` functionality needed to implement proper path resolution in WASI. On Linux, it's implemented by stringing together `fstatat` and `readlinkat(2)`. On Darwin, since `fstatat(2)` does not support the `AT_SYMLINK_NOFOLLOW` flag, we use `lstat(2)`. Signed-off-by: Yage Hu <[email protected]>
Signed-off-by: Yage Hu <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
This PR is the second in a series that will implement the path resolution algorithm described by wasi-filesystem. This PR currently targets the main branch and thus includes changes in part 1 (#2254). When #2254 is merged I'll rebase this PR.
This PR adds the
readlinkat(2)syscall to Linux and Darwin and the equivalent on Windows. This is needed to support the path resolution algorithm by expanding symlinks as we encounter them when resolving paths.