fs: cache the string generated by reading /proc/filesystems

It is being read surprisingly often (e.g., by mkdir, ls and even sed!).

This is lock-protected pointer chasing over a linked list to pay for
sprintf for every fs (32 on my boxen).

Instead cache the result.

While here make the file as permanent to avoid spurious ref trips in
procfs.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260425220844.1763933-4-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

0 files changed, 0 insertions, 0 deletions