On Sun, 23 Feb 2025 at 01:28, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > On Thu, Feb 20, 2025 at 11:02:58AM +0100, Miklos Szeredi wrote: > > > The solution is to just remove this truncation. This can cause a > > regression in a filesystem that relies on supplying a symlink larger than > > the file size, but this is unlikely. If that happens we'd need to make > > this behavior conditional. > > Note, BTW, that page *contents* must not change at all, so truncation is > only safe if we have ->i_size guaranteed to be stable. > > Core pathwalk really counts upon the string remaining immutable, and that > does include the string returned by ->get_link(). Page contents will not change after initial readlink, but page could get invalidated and a fresh page filled with new value for the same object. It's weird behavior all right, but seems to be useful in a couple of cases where invalidating the dentry wouldn't work (I don't remember the details, cvmfs folks can help with that). Thanks, Miklos
