Go expects the error to be one of the three errors returned in
Bell Labs Plan 9. As listed in
f7ba82d68f/src/cmd/go/internal/lockedfile/lockedfile_plan9.go (L16):
// Opening an exclusive-use file returns an error.
// The expected error strings are:
//
// - "open/create -- file is locked" (cwfs, kfs)
// - "exclusive lock" (fossil)
// - "exclusive use file already open" (ramfs)
var lockedErrStrings = [...]string{
"file is locked",
"exclusive lock",
"exclusive use file already open",
}
old ramfs had a limit on the number of files it could serve
and file size was limited to maximum allocaiton size.
the new implementation uses multiple memory chunks to back file data
in a private compactable memory pool to overcome these limits.
files can be sparse. file metadata is maintained by 9pfile data
structures of lib9p.
