On Wed, Mar 17, 2010 at 07:51:31AM +0900, J. R. Okajima wrote: > > Valerie Aurora: > > 1. Don't copyup if the operation would fail (e.g., open(O_WRONLY) on a > > file with mode 444). It's inefficient and a possible security hole to > > copy up a file if no write (or maybe even read) can occur anyway. > > Just a question. > How about this case? > When the file is writable (0644 or something) but its parent directory > is readonly (0555), do you think the file should be copied-up? This problem comes up with readdir() too, since we copy up all the directory entries from the lower layer on what is ostensibly a read-only access. I think what people will expect is that we copy up in that case. I can think of ways this can go wrong, but perhaps that should be an explicit requirement on the top-layer file system, that it can handle create/unlink() in a directory without write permission. -VAL -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
