* mount: implement create for rsync temp files
* mount: move access implementation out of unsupported
* mount: tighten access checks
* mount: log access group lookup failures
* mount: reset dirty pages on truncate
* mount: tighten create and root access handling
* mount: handle existing creates before quota checks
* mount: restrict access fallback when group lookup fails
When lookupSupplementaryGroupIDs returns an error, the previous code
fell through to checking only the "other" permission bits, which could
overgrant access. Require both group and other permission classes to
satisfy the mask so access is never broader than intended.
* mount: guard against nil entry in Create existing-file path
maybeLoadEntry can return OK with a nil entry or nil Attributes in
edge cases. Check before dereferencing to prevent a panic.
* mount: reopen existing file on create race without O_EXCL
When createRegularFile returns EEXIST because another process won the
race, and O_EXCL is not set, reload the winner's entry and open it
instead of propagating the error to the caller.
* mount: check parent directory permission in createRegularFile
Verify the caller has write+search (W_OK|X_OK) permission on the
parent directory before creating a file. This applies to both
Create and Mknod. Update test fixture mount mode to 0o777 so the
existing tests pass with the new check.
* mount: enforce file permission bits in AcquireHandle
Map the open flags (O_RDONLY/O_WRONLY/O_RDWR) to an access mask and
call hasAccess before handing out a file handle. This makes
AcquireHandle the single source of truth for mode-based access
control across Open, Create-existing, and Create-new paths.
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Co-authored-by: Copilot <copilot@github.com>
Chris Lu
cca1555cc7