freebsd-skq/sys/fs/fuse/fuse_ipc.h
Edward Tomasz Napierala e3b1c847a4 Make it possible to mount a fuse filesystem, such as squashfuse,
from a Linux binary.  Should come handy for AppImages.

Reviewed by:	asomers
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D26959
2020-11-09 08:53:15 +00:00

430 lines
12 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2007-2009 Google Inc. and Amit Singh
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright (C) 2005 Csaba Henk.
* All rights reserved.
*
* Copyright (c) 2019 The FreeBSD Foundation
*
* Portions of this software were developed by BFF Storage Systems, LLC under
* sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _FUSE_IPC_H_
#define _FUSE_IPC_H_
#include <sys/param.h>
#include <sys/refcount.h>
enum fuse_data_cache_mode {
FUSE_CACHE_UC,
FUSE_CACHE_WT,
FUSE_CACHE_WB,
};
struct fuse_iov {
void *base;
size_t len;
size_t allocated_size;
int credit;
};
void fiov_init(struct fuse_iov *fiov, size_t size);
void fiov_teardown(struct fuse_iov *fiov);
void fiov_refresh(struct fuse_iov *fiov);
void fiov_adjust(struct fuse_iov *fiov, size_t size);
#define FUSE_DIMALLOC(fiov, spc1, spc2, amnt) do { \
fiov_adjust(fiov, (sizeof(*(spc1)) + (amnt))); \
(spc1) = (fiov)->base; \
(spc2) = (char *)(fiov)->base + (sizeof(*(spc1))); \
} while (0)
#define FU_AT_LEAST(siz) max((siz), 160)
#define FUSE_ASSERT_AW_DONE(ftick) \
KASSERT((ftick)->tk_aw_link.tqe_next == NULL && \
(ftick)->tk_aw_link.tqe_prev == NULL, \
("FUSE: ticket still on answer delivery list %p", (ftick)))
#define FUSE_ASSERT_MS_DONE(ftick) \
KASSERT((ftick)->tk_ms_link.stqe_next == NULL, \
("FUSE: ticket still on message list %p", (ftick)))
struct fuse_ticket;
struct fuse_data;
typedef int fuse_handler_t(struct fuse_ticket *ftick, struct uio *uio);
struct fuse_ticket {
/* fields giving the identity of the ticket */
uint64_t tk_unique;
struct fuse_data *tk_data;
int tk_flag;
u_int tk_refcount;
/*
* If this ticket's operation has been interrupted, this will hold the
* unique value of the FUSE_INTERRUPT operation. Otherwise, it will be
* 0.
*/
uint64_t irq_unique;
/* fields for initiating an upgoing message */
struct fuse_iov tk_ms_fiov;
void *tk_ms_bufdata;
size_t tk_ms_bufsize;
enum { FT_M_FIOV, FT_M_BUF } tk_ms_type;
STAILQ_ENTRY(fuse_ticket) tk_ms_link;
/* fields for handling answers coming from userspace */
struct fuse_iov tk_aw_fiov;
void *tk_aw_bufdata;
size_t tk_aw_bufsize;
enum { FT_A_FIOV, FT_A_BUF } tk_aw_type;
struct fuse_out_header tk_aw_ohead;
int tk_aw_errno;
struct mtx tk_aw_mtx;
fuse_handler_t *tk_aw_handler;
TAILQ_ENTRY(fuse_ticket) tk_aw_link;
};
#define FT_ANSW 0x01 /* request of ticket has already been answered */
#define FT_DIRTY 0x04 /* ticket has been used */
static inline struct fuse_iov *
fticket_resp(struct fuse_ticket *ftick)
{
return (&ftick->tk_aw_fiov);
}
static inline bool
fticket_answered(struct fuse_ticket *ftick)
{
mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
return (ftick->tk_flag & FT_ANSW);
}
static inline void
fticket_set_answered(struct fuse_ticket *ftick)
{
mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
ftick->tk_flag |= FT_ANSW;
}
static inline struct fuse_in_header*
fticket_in_header(struct fuse_ticket *ftick)
{
return (struct fuse_in_header *)(ftick->tk_ms_fiov.base);
}
static inline enum fuse_opcode
fticket_opcode(struct fuse_ticket *ftick)
{
return fticket_in_header(ftick)->opcode;
}
int fticket_pull(struct fuse_ticket *ftick, struct uio *uio);
/*
* The data representing a FUSE session.
*/
struct fuse_data {
struct cdev *fdev;
struct mount *mp;
struct vnode *vroot;
struct ucred *daemoncred;
int dataflags;
int ref;
struct mtx ms_mtx;
STAILQ_HEAD(, fuse_ticket) ms_head;
int ms_count;
struct mtx aw_mtx;
TAILQ_HEAD(, fuse_ticket) aw_head;
/*
* Holds the next value of the FUSE operation unique value.
* Also, serves as a wakeup channel to prevent any operations from
* being created before INIT completes.
*/
u_long ticketer;
struct sx rename_lock;
uint32_t fuse_libabi_major;
uint32_t fuse_libabi_minor;
uint32_t max_readahead_blocks;
uint32_t max_write;
uint32_t max_read;
uint32_t subtype;
char volname[MAXPATHLEN];
struct selinfo ks_rsel;
int daemon_timeout;
int linux_errnos;
unsigned time_gran;
uint64_t notimpl;
uint64_t mnt_flag;
enum fuse_data_cache_mode cache_mode;
};
#define FSESS_DEAD 0x0001 /* session is to be closed */
#define FSESS_INITED 0x0004 /* session has been inited */
#define FSESS_DAEMON_CAN_SPY 0x0010 /* let non-owners access this fs */
/* (and being observed by the daemon) */
#define FSESS_PUSH_SYMLINKS_IN 0x0020 /* prefix absolute symlinks with mp */
#define FSESS_DEFAULT_PERMISSIONS 0x0040 /* kernel does permission checking */
#define FSESS_ASYNC_READ 0x1000 /* allow multiple reads of some file */
#define FSESS_POSIX_LOCKS 0x2000 /* daemon supports POSIX locks */
#define FSESS_EXPORT_SUPPORT 0x10000 /* daemon supports NFS-style lookups */
#define FSESS_INTR 0x20000 /* interruptible mounts */
#define FSESS_MNTOPTS_MASK ( \
FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \
FSESS_DEFAULT_PERMISSIONS | FSESS_INTR)
extern int fuse_data_cache_mode;
static inline struct fuse_data *
fuse_get_mpdata(struct mount *mp)
{
return mp->mnt_data;
}
static inline bool
fsess_isimpl(struct mount *mp, int opcode)
{
struct fuse_data *data = fuse_get_mpdata(mp);
return ((data->notimpl & (1ULL << opcode)) == 0);
}
static inline void
fsess_set_notimpl(struct mount *mp, int opcode)
{
struct fuse_data *data = fuse_get_mpdata(mp);
data->notimpl |= (1ULL << opcode);
}
static inline bool
fsess_opt_datacache(struct mount *mp)
{
struct fuse_data *data = fuse_get_mpdata(mp);
return (data->cache_mode != FUSE_CACHE_UC);
}
static inline bool
fsess_opt_mmap(struct mount *mp)
{
return (fsess_opt_datacache(mp));
}
static inline bool
fsess_opt_writeback(struct mount *mp)
{
struct fuse_data *data = fuse_get_mpdata(mp);
return (data->cache_mode == FUSE_CACHE_WB);
}
/* Insert a new upgoing message */
static inline void
fuse_ms_push(struct fuse_ticket *ftick)
{
mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
refcount_acquire(&ftick->tk_refcount);
STAILQ_INSERT_TAIL(&ftick->tk_data->ms_head, ftick, tk_ms_link);
ftick->tk_data->ms_count++;
}
/* Insert a new upgoing message to the front of the queue */
static inline void
fuse_ms_push_head(struct fuse_ticket *ftick)
{
mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
refcount_acquire(&ftick->tk_refcount);
STAILQ_INSERT_HEAD(&ftick->tk_data->ms_head, ftick, tk_ms_link);
ftick->tk_data->ms_count++;
}
static inline struct fuse_ticket *
fuse_ms_pop(struct fuse_data *data)
{
struct fuse_ticket *ftick = NULL;
mtx_assert(&data->ms_mtx, MA_OWNED);
if ((ftick = STAILQ_FIRST(&data->ms_head))) {
STAILQ_REMOVE_HEAD(&data->ms_head, tk_ms_link);
data->ms_count--;
#ifdef INVARIANTS
MPASS(data->ms_count >= 0);
ftick->tk_ms_link.stqe_next = NULL;
#endif
}
return (ftick);
}
static inline void
fuse_aw_push(struct fuse_ticket *ftick)
{
mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
refcount_acquire(&ftick->tk_refcount);
TAILQ_INSERT_TAIL(&ftick->tk_data->aw_head, ftick, tk_aw_link);
}
static inline void
fuse_aw_remove(struct fuse_ticket *ftick)
{
mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
TAILQ_REMOVE(&ftick->tk_data->aw_head, ftick, tk_aw_link);
#ifdef INVARIANTS
ftick->tk_aw_link.tqe_next = NULL;
ftick->tk_aw_link.tqe_prev = NULL;
#endif
}
static inline struct fuse_ticket *
fuse_aw_pop(struct fuse_data *data)
{
struct fuse_ticket *ftick;
mtx_assert(&data->aw_mtx, MA_OWNED);
if ((ftick = TAILQ_FIRST(&data->aw_head)) != NULL)
fuse_aw_remove(ftick);
return (ftick);
}
struct fuse_ticket *fuse_ticket_fetch(struct fuse_data *data);
int fuse_ticket_drop(struct fuse_ticket *ftick);
void fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t *handler);
void fuse_insert_message(struct fuse_ticket *ftick, bool irq);
static inline bool
fuse_libabi_geq(struct fuse_data *data, uint32_t abi_maj, uint32_t abi_min)
{
return (data->fuse_libabi_major > abi_maj ||
(data->fuse_libabi_major == abi_maj &&
data->fuse_libabi_minor >= abi_min));
}
struct fuse_data *fdata_alloc(struct cdev *dev, struct ucred *cred);
void fdata_trydestroy(struct fuse_data *data);
void fdata_set_dead(struct fuse_data *data);
static inline bool
fdata_get_dead(struct fuse_data *data)
{
return (data->dataflags & FSESS_DEAD);
}
struct fuse_dispatcher {
struct fuse_ticket *tick;
struct fuse_in_header *finh;
void *indata;
size_t iosize;
uint64_t nodeid;
int answ_stat;
void *answ;
};
static inline void
fdisp_init(struct fuse_dispatcher *fdisp, size_t iosize)
{
fdisp->iosize = iosize;
fdisp->tick = NULL;
}
static inline void
fdisp_destroy(struct fuse_dispatcher *fdisp)
{
fuse_ticket_drop(fdisp->tick);
#ifdef INVARIANTS
fdisp->tick = NULL;
#endif
}
void fdisp_refresh(struct fuse_dispatcher *fdip);
void fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op,
struct mount *mp, uint64_t nid, struct thread *td, struct ucred *cred);
void fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
struct vnode *vp, struct thread *td, struct ucred *cred);
void fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
struct vnode *vp, struct thread *td, struct ucred *cred);
int fdisp_wait_answ(struct fuse_dispatcher *fdip);
static inline int
fdisp_simple_putget_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
struct vnode *vp, struct thread *td, struct ucred *cred)
{
fdisp_make_vp(fdip, op, vp, td, cred);
return (fdisp_wait_answ(fdip));
}
#endif /* _FUSE_IPC_H_ */