fuse_i.h

/*
  FUSE: Filesystem in Userspace
  Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
 
  This program can be distributed under the terms of the GNU LGPLv2.
  See the file COPYING.LIB
*/
 
#include "fuse.h"
#include "fuse_lowlevel.h"
#include "util.h"
 
#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include <stdatomic.h>
 
#define MIN(a, b) \
({                                                                      \
        typeof(a) _a = (a);                                             \
        typeof(b) _b = (b);                                             \
        _a < _b ? _a : _b;                                              \
})
 
struct mount_opts;
 
struct fuse_req {
        struct fuse_session *se;
        uint64_t unique;
        _Atomic int ref_cnt;
        pthread_mutex_t lock;
        struct fuse_ctx ctx;
        struct fuse_chan *ch;
        int interrupted;
        unsigned int ioctl_64bit : 1;
        union {
                struct {
                        uint64_t unique;
                } i;
                struct {
                        fuse_interrupt_func_t func;
                        void *data;
                } ni;
        } u;
        struct fuse_req *next;
        struct fuse_req *prev;
};
 
struct fuse_notify_req {
        uint64_t unique;
        void (*reply)(struct fuse_notify_req *, fuse_req_t, fuse_ino_t,
                      const void *, const struct fuse_buf *);
        struct fuse_notify_req *next;
        struct fuse_notify_req *prev;
};
 
struct fuse_session {
        _Atomic(char *)mountpoint;
        volatile int exited;
        int fd;
        struct fuse_custom_io *io;
        struct mount_opts *mo;
        int debug;
        int deny_others;
        struct fuse_lowlevel_ops op;
        int got_init;
        struct cuse_data *cuse_data;
        void *userdata;
        uid_t owner;
        struct fuse_conn_info conn;
        struct fuse_req list;
        struct fuse_req interrupts;
        pthread_mutex_t lock;
        int got_destroy;
        pthread_key_t pipe_key;
        int broken_splice_nonblock;
        uint64_t notify_ctr;
        struct fuse_notify_req notify_list;
        _Atomic size_t bufsize;
        int error;
 
        /* This is useful if any kind of ABI incompatibility is found at
         * a later version, to 'fix' it at run time.
         */
        struct libfuse_version version;
 
        /* true if reading requests from /dev/fuse are handled internally */
        bool buf_reallocable;
 
        /*
         * conn->want and conn_want_ext options set by libfuse , needed
         * to correctly convert want to want_ext
         */
        uint32_t conn_want;
        uint64_t conn_want_ext;
};
 
struct fuse_chan {
        pthread_mutex_t lock;
        int ctr;
        int fd;
};
 
struct fuse_module {
        char *name;
        fuse_module_factory_t factory;
        struct fuse_module *next;
        struct fusemod_so *so;
        int ctr;
};
 
#if FUSE_USE_VERSION >= FUSE_MAKE_VERSION(3, 12)
struct fuse_loop_config
{
        /* verififier that a correct struct was was passed. This is especially
         * needed, as versions below (3, 12) were using a public struct
         * (now called  fuse_loop_config_v1), which was hard to extend with
         * additional parameters, without risking that file system implementations
         * would not have noticed and might either pass uninitialized members
         * or even too small structs.
         * fuse_loop_config_v1 has clone_fd at this offset, which should be either 0
         * or 1. v2 or even higher version just need to set a value here
         * which not conflicting and very unlikely as having been set by
         * file system implementation.
         */
        int version_id;
 
        int clone_fd;
        int max_idle_threads;
 
        unsigned int max_threads;
};
#endif
 
/* ----------------------------------------------------------- *
 * Channel interface (when using -o clone_fd)                  *
 * ----------------------------------------------------------- */
 
struct fuse_chan *fuse_chan_get(struct fuse_chan *ch);
 
void fuse_chan_put(struct fuse_chan *ch);
 
struct mount_opts *parse_mount_opts(struct fuse_args *args);
void destroy_mount_opts(struct mount_opts *mo);
void fuse_mount_version(void);
unsigned get_max_read(struct mount_opts *o);
void fuse_kern_unmount(const char *mountpoint, int fd);
int fuse_kern_mount(const char *mountpoint, struct mount_opts *mo);
 
int fuse_send_reply_iov_nofree(fuse_req_t req, int error, struct iovec *iov,
                               int count);
void fuse_free_req(fuse_req_t req);
 
void cuse_lowlevel_init(fuse_req_t req, fuse_ino_t nodeide, const void *inarg);
 
int fuse_start_thread(pthread_t *thread_id, void *(*func)(void *), void *arg);
 
void fuse_buf_free(struct fuse_buf *buf);
 
int fuse_session_receive_buf_internal(struct fuse_session *se,
                                      struct fuse_buf *buf,
                                      struct fuse_chan *ch);
void fuse_session_process_buf_internal(struct fuse_session *se,
                                       const struct fuse_buf *buf,
                                       struct fuse_chan *ch);
 
struct fuse *fuse_new_31(struct fuse_args *args, const struct fuse_operations *op,
                      size_t op_size, void *private_data);
int fuse_loop_mt_312(struct fuse *f, struct fuse_loop_config *config);
int fuse_session_loop_mt_312(struct fuse_session *se, struct fuse_loop_config *config);
 
int fuse_loop_cfg_verify(struct fuse_loop_config *config);
 
 
/*
 * This can be changed dynamically on recent kernels through the
 * /proc/sys/fs/fuse/max_pages_limit interface.
 *
 * Older kernels will always use the default value.
 */
#define FUSE_DEFAULT_MAX_PAGES_LIMIT 256
#define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32
 
/* room needed in buffer to accommodate header */
#define FUSE_BUFFER_HEADER_SIZE 0x1000