Commit 3ab394b3 authored by Bernd Schubert's avatar Bernd Schubert Committed by Miklos Szeredi
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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: 7dc4e97a ("fuse: introduce FUSE_PASSTHROUGH capability")
Cc: stable@kernel.org # v6.9
Signed-off-by: default avatarBernd Schubert <bschubert@ddn.com>
Acked-by: default avatarAmir Goldstein <amir73il@gmail.com>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent f7790d67

fs/fuse/inode.c

+6 −1
Original line number Diff line number Diff line
@@ -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;