Sokhi got a read-only error from the cover-art filler with NO ':ro' in his
compose. Root cause: my earlier Tim fix added a statvfs pre-flight that bailed
when f_flag & ST_RDONLY — but union/FUSE/network filesystems (mergerfs,
rclone, NFS), ubiquitous in self-hosted setups, misreport those mount flags.
A perfectly writable library could be flagged read-only and blocked. statvfs
is a guess; the only honest test is whether an actual write raises EROFS.
- Removed the statvfs pre-flight entirely. Read-only is now detected solely
from a real EROFS on the embed write, which also fast-fails the remaining
files (so no statvfs needed for the fast-fail Tim wanted either).
- Broadened the user message: a genuine read-only mount isn't always ':ro' —
could be a read-only host/NFS/SMB mount or a mergerfs read-only branch.
Tests: writable FS succeeds even when statvfs would claim read-only (the
regression), real-EROFS-on-write still flagged + bails the rest, EACCES still
not conflated with EROFS. Dropped the now-moot Windows-statvfs test (statvfs
is no longer referenced). 445 art/cover/repair tests pass.
6c3e285a49