Files
linux/fs/fuse/req.c
Miklos Szeredi 794e811d14 fuse: split out filesystem part of request sending
Create a new source file: req.c and add the request sending entry
functions:

  __fuse_simple_request()
  fuse_simple_background()
  fuse_simple_notify_reply()

Introduce transport layer sending functions that are called by the
respective fs layer function:

  fuse_chan_send()
  fuse_chan_send_bg()
  fuse_chan_send_notify_reply()

Move calculation of request header fields uid, gid and pid from
fuse_get_req() and fuse_force_creads() to a new helper: fuse_fill_creds().

These fileds are now passed to the transport layer via struct fuse_args.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-06-15 14:06:17 +02:00

100 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include "dev.h"
#include "fuse_i.h"
static int fuse_fill_creds(struct fuse_mount *fm, struct fuse_args *args, struct mnt_idmap *idmap)
{
struct fuse_conn *fc = fm->fc;
bool no_idmap = !fm->sb || (fm->sb->s_iflags & SB_I_NOIDMAP);
kuid_t fsuid = mapped_fsuid(idmap, fc->user_ns);
kgid_t fsgid = mapped_fsgid(idmap, fc->user_ns);
args->pid = pid_nr_ns(task_pid(current), fc->pid_ns);
if (args->force) {
if (args->nocreds)
return 0;
if (no_idmap) {
args->uid = from_kuid_munged(fc->user_ns, current_fsuid());
args->gid = from_kgid_munged(fc->user_ns, current_fsgid());
} else {
args->uid = FUSE_INVALID_UIDGID;
args->gid = FUSE_INVALID_UIDGID;
}
return 0;
}
WARN_ON(args->nocreds);
/*
* Keep the old behavior when idmappings support was not
* declared by a FUSE server.
*
* For those FUSE servers who support idmapped mounts, we send UID/GID
* only along with "inode creation" fuse requests, otherwise idmap ==
* &invalid_mnt_idmap and req->in.h.{u,g}id will be equal to
* FUSE_INVALID_UIDGID.
*/
if (no_idmap) {
fsuid = current_fsuid();
fsgid = current_fsgid();
}
args->uid = from_kuid(fc->user_ns, fsuid);
args->gid = from_kgid(fc->user_ns, fsgid);
if (no_idmap && unlikely(args->uid == ((uid_t)-1) || args->gid == ((gid_t)-1)))
return -EOVERFLOW;
return 0;
}
static int fuse_req_prep(struct fuse_mount *fm, struct fuse_args *args, struct mnt_idmap *idmap)
{
if (!args->force && fm->fc->conn_error)
return -ECONNREFUSED;
return fuse_fill_creds(fm, args, idmap);
}
ssize_t __fuse_simple_request(struct mnt_idmap *idmap, struct fuse_mount *fm,
struct fuse_args *args)
{
struct fuse_conn *fc = fm->fc;
int err = fuse_req_prep(fm, args, idmap);
if (err)
return err;
return fuse_chan_send(fc->chan, args);
}
int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args, gfp_t gfp_flags)
{
struct fuse_conn *fc = fm->fc;
int err;
WARN_ON(args->force && !args->nocreds);
err = fuse_req_prep(fm, args, &invalid_mnt_idmap);
if (err)
return err;
return fuse_chan_send_bg(fc->chan, args, gfp_flags);
}
EXPORT_SYMBOL_GPL(fuse_simple_background);
int fuse_simple_notify_reply(struct fuse_mount *fm, struct fuse_args *args, u64 unique)
{
struct fuse_conn *fc = fm->fc;
int err;
WARN_ON(args->force && !args->nocreds);
err = fuse_req_prep(fm, args, &invalid_mnt_idmap);
if (err)
return err;
return fuse_chan_send_notify_reply(fc->chan, args, unique);
}