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Commit e413754b authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: add nocreds to fuse_args 



In some cases it makes no sense to set pid/uid/gid fields in the request
header.  Allow fuse_simple_background() to omit these.  This is only
required in the "force" case, so for now just WARN if set otherwise.

Fold fuse_get_req_nofail_nopages() into its only caller.  Comment is
obsolete anyway.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 3545fe21

fs/fuse/dev.c

+15 −29
Original line number Diff line number Diff line
@@ -242,34 +242,6 @@ struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc, 
}

EXPORT_SYMBOL_GPL(fuse_get_req_for_background);



/*

 * Gets a requests for a file operation, always succeeds

 *

 * This is used for sending the FLUSH request, which must get to

 * userspace, due to POSIX locks which may need to be unlocked.

 *

 * If allocation fails due to OOM, use the reserved request in

 * fuse_file.

 *

 * This is very unlikely to deadlock accidentally, since the

 * filesystem should not have it's own file open.  If deadlock is

 * intentional, it can still be broken by "aborting" the filesystem.

 */

static struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc)

{

	struct fuse_req *req;



	atomic_inc(&fc->num_waiting);

	req = __fuse_request_alloc(0, GFP_KERNEL | __GFP_NOFAIL);



	req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid());

	req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid());

	req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);



	__set_bit(FR_WAITING, &req->flags);

	return req;

}



void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)

{

	if (refcount_dec_and_test(&req->count)) {
@@ -565,15 +537,29 @@ static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args) 
	}

}



static void fuse_force_creds(struct fuse_conn *fc, struct fuse_req *req)

{

	req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid());

	req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid());

	req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);

}



ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)

{

	struct fuse_req *req;

	ssize_t ret;



	if (args->force) {

		req = fuse_get_req_nofail_nopages(fc);

		atomic_inc(&fc->num_waiting);

		req = __fuse_request_alloc(0, GFP_KERNEL | __GFP_NOFAIL);



		if (!args->nocreds)

			fuse_force_creds(fc, req);



		__set_bit(FR_WAITING, &req->flags);

		__set_bit(FR_FORCE, &req->flags);

	} else {

		WARN_ON(args->nocreds);

		req = fuse_get_req(fc, 0);

		if (IS_ERR(req))

			return PTR_ERR(req);

fs/fuse/fuse_i.h

+1 −0
Original line number Diff line number Diff line
@@ -293,6 +293,7 @@ struct fuse_args { 
	unsigned short out_numargs;

	bool force:1;

	bool noreply:1;

	bool nocreds:1;

	bool out_argvar:1;

	struct fuse_in_arg in_args[3];

	struct fuse_arg out_args[2];