From 3ab394b363c5fd14b231e335fb6746ddfb93aaaa Mon Sep 17 00:00:00 2001 From: Bernd Schubert Date: Wed, 3 Jul 2024 19:30:20 +0200 Subject: fuse: disable the combination of passthrough and writeback cache Current design and handling of passthrough is without fuse caching and with that FUSE_WRITEBACK_CACHE is conflicting. Fixes: 7dc4e97a4f9a ("fuse: introduce FUSE_PASSTHROUGH capability") Cc: stable@kernel.org # v6.9 Signed-off-by: Bernd Schubert Acked-by: Amir Goldstein Reviewed-by: Josef Bacik Signed-off-by: Miklos Szeredi --- fs/fuse/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'fs/fuse') diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index d8ab4e93916f..bebd89002328 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1332,11 +1332,16 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, * on a stacked fs (e.g. overlayfs) themselves and with * max_stack_depth == 1, FUSE fs can be stacked as the * underlying fs of a stacked fs (e.g. overlayfs). + * + * Also don't allow the combination of FUSE_PASSTHROUGH + * and FUSE_WRITEBACK_CACHE, current design doesn't handle + * them together. */ if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH) && (flags & FUSE_PASSTHROUGH) && arg->max_stack_depth > 0 && - arg->max_stack_depth <= FILESYSTEM_MAX_STACK_DEPTH) { + arg->max_stack_depth <= FILESYSTEM_MAX_STACK_DEPTH && + !(flags & FUSE_WRITEBACK_CACHE)) { fc->passthrough = 1; fc->max_stack_depth = arg->max_stack_depth; fm->sb->s_stack_depth = arg->max_stack_depth; -- cgit v1.2.3-70-g09d2