QUERY · ISSUE

VFS FatFS: mkdir with trailing slash fails when it should succeed

openby dpgeorgeopened 2017-03-03updated 2017-03-08

On CPython and unix uPy, os.mkdir('directory/') makes the requested directory. But on bare metal ports using VFS with FatFS it fails with ENOENT because of the trailing slash. I'd say this should be fixed. (And in fact CPy and unix uPy allow any number of trailing slashes).

CANDIDATE · PULL REQUEST

extmod/vfs: Fix lookup of entry in root dir so it fails correctly.

mergedby dpgeorgeopened 2020-09-22updated 2020-09-23

extmod

Prior to this commit, uos.chdir('/') followed by uos.stat('noexist') would succeed that stat even though the entry did not exist (some other functions like listdir would have similar issues). This is because, if the current directory was the root and the path was relative, mp_vfs_lookup_path would return success for bad paths.

Assessment

Q Qwen · medium

The query (issue #2929) reports that os.mkdir() with a trailing slash fails on bare metal ports using VFS/FatFS, while it should succeed like on CPython and Unix uPy. The candidate (PR #6467) fixes a different VFS bug where mp_vfs_lookup_path incorrectly succeeded for non-existent paths in the root directory. While both involve VFS path handling and the PR modifies extmod/vfs.c, the PR addresses incorrect success behavior for non-existent paths, whereas the issue is about incorrect failure behavior for valid paths with trailing slashes. The PR does not address the trailing slash handling in mkdir specifically.

Suggested action

Keep both items open. The PR does not resolve the trailing slash issue reported in the query. The query should be investigated separately for FatFS path normalization in mkdir operations.

VFS FatFS: mkdir with trailing slash fails when it should succeed

extmod/vfs: Fix lookup of entry in root dir so it fails correctly.

Keyboard