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485 lines
12 KiB
485 lines
12 KiB
/*
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FUSE: Filesystem in Userspace
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Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
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This program can be distributed under the terms of the GNU LGPLv2.
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See the file COPYING.LIB.
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*/
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/** @file */
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#if !defined(_FUSE_H_) && !defined(_FUSE_LOWLEVEL_H_)
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#error "Never include <fuse_common.h> directly; use <fuse.h> or <fuse_lowlevel.h> instead."
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#endif
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#ifndef _FUSE_COMMON_H_
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#define _FUSE_COMMON_H_
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#include "extern_c.h"
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#include "fuse_opt.h"
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#include "fuse_timeouts.h"
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#include <stdint.h>
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#include <sys/types.h>
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/** Major version of FUSE library interface */
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#define FUSE_MAJOR_VERSION 2
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/** Minor version of FUSE library interface */
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#define FUSE_MINOR_VERSION 9
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#define FUSE_MAKE_VERSION(maj, min) ((maj) * 10 + (min))
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#define FUSE_VERSION FUSE_MAKE_VERSION(FUSE_MAJOR_VERSION, FUSE_MINOR_VERSION)
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/* This interface uses 64 bit off_t */
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#if _FILE_OFFSET_BITS != 64
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#error Please add -D_FILE_OFFSET_BITS=64 to your compile flags!
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#endif
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#define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32
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#define FUSE_MAX_MAX_PAGES 256
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EXTERN_C_BEGIN
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/**
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* Information about open files
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*
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* Changed in version 2.5
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*/
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typedef struct fuse_file_info_t fuse_file_info_t;
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struct fuse_file_info_t
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{
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/** Open flags. Available in open() and release() */
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int flags;
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/** In case of a write operation indicates if this was caused by a
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writepage */
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uint32_t writepage : 1;
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/** Can be filled in by open, to use direct I/O on this file.
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Introduced in version 2.4 */
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uint32_t direct_io : 1;
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/** Can be filled in by open, to indicate, that cached file data
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need not be invalidated. Introduced in version 2.4 */
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uint32_t keep_cache : 1;
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/** Indicates a flush operation. Set in flush operation, also
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maybe set in highlevel lock operation and lowlevel release
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operation. Introduced in version 2.6 */
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uint32_t flush : 1;
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/** Can be filled in by open, to indicate that the file is not
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seekable. Introduced in version 2.8 */
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uint32_t nonseekable : 1;
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/* Indicates that flock locks for this file should be
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released. If set, lock_owner shall contain a valid value.
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May only be set in ->release(). Introduced in version
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2.9 */
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uint32_t flock_release : 1;
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/* Requests the kernel to cache entries returned by readdir */
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uint32_t cache_readdir : 1;
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uint32_t auto_cache : 1;
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/** File handle. May be filled in by filesystem in open().
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Available in all other file operations */
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uint64_t fh;
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/** Lock owner id. Available in locking operations and flush */
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uint64_t lock_owner;
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};
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/**
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* Capability bits for 'fuse_conn_info.capable' and 'fuse_conn_info.want'
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*
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* FUSE_CAP_ASYNC_READ: filesystem supports asynchronous read requests
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* FUSE_CAP_POSIX_LOCKS: filesystem supports "remote" locking
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* FUSE_CAP_ATOMIC_O_TRUNC: filesystem handles the O_TRUNC open flag
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* FUSE_CAP_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
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* FUSE_CAP_BIG_WRITES: filesystem can handle write size larger than 4kB
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* FUSE_CAP_DONT_MASK: don't apply umask to file mode on create operations
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* FUSE_CAP_SPLICE_WRITE: ability to use splice() to write to the fuse device
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* FUSE_CAP_SPLICE_MOVE: ability to move data to the fuse device with splice()
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* FUSE_CAP_SPLICE_READ: ability to use splice() to read from the fuse device
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* FUSE_CAP_IOCTL_DIR: ioctl support on directories
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* FUSE_CAP_CACHE_SYMLINKS: cache READLINK responses
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*/
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#define FUSE_CAP_ASYNC_READ (1 << 0)
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#define FUSE_CAP_POSIX_LOCKS (1 << 1)
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#define FUSE_CAP_ATOMIC_O_TRUNC (1 << 3)
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#define FUSE_CAP_EXPORT_SUPPORT (1 << 4)
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#define FUSE_CAP_BIG_WRITES (1 << 5)
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#define FUSE_CAP_DONT_MASK (1 << 6)
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#define FUSE_CAP_SPLICE_WRITE (1 << 7)
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#define FUSE_CAP_SPLICE_MOVE (1 << 8)
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#define FUSE_CAP_SPLICE_READ (1 << 9)
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#define FUSE_CAP_FLOCK_LOCKS (1 << 10)
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#define FUSE_CAP_IOCTL_DIR (1 << 11)
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#define FUSE_CAP_READDIR_PLUS (1 << 13)
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#define FUSE_CAP_READDIR_PLUS_AUTO (1 << 14)
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#define FUSE_CAP_ASYNC_DIO (1 << 15)
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#define FUSE_CAP_WRITEBACK_CACHE (1 << 16)
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#define FUSE_CAP_PARALLEL_DIROPS (1 << 18)
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#define FUSE_CAP_POSIX_ACL (1 << 19)
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#define FUSE_CAP_CACHE_SYMLINKS (1 << 20)
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#define FUSE_CAP_MAX_PAGES (1 << 21)
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#define FUSE_CAP_SETXATTR_EXT (1 << 22)
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/**
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* Ioctl flags
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*
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* FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
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* FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
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* FUSE_IOCTL_RETRY: retry with new iovecs
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* FUSE_IOCTL_DIR: is a directory
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*
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* FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
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*/
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#define FUSE_IOCTL_COMPAT (1 << 0)
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#define FUSE_IOCTL_UNRESTRICTED (1 << 1)
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#define FUSE_IOCTL_RETRY (1 << 2)
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#define FUSE_IOCTL_DIR (1 << 4)
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#define FUSE_IOCTL_MAX_IOV 256
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/**
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* Connection information, passed to the ->init() method
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*
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* Some of the elements are read-write, these can be changed to
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* indicate the value requested by the filesystem. The requested
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* value must usually be smaller than the indicated value.
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*/
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struct fuse_conn_info {
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/**
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* Major version of the protocol (read-only)
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*/
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unsigned proto_major;
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/**
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* Minor version of the protocol (read-only)
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*/
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unsigned proto_minor;
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/**
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* Maximum size of the write buffer
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*/
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unsigned max_write;
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/**
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* Maximum readahead
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*/
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unsigned max_readahead;
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/**
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* Capability flags, that the kernel supports
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*/
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unsigned capable;
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/**
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* Capability flags, that the filesystem wants to enable
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*/
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unsigned want;
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/**
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* Maximum number of backgrounded requests
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*/
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unsigned max_background;
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/**
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* Kernel congestion threshold parameter
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*/
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unsigned congestion_threshold;
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/**
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* Max pages
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*/
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uint16_t max_pages;
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/**
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* For future use.
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*/
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unsigned reserved[22];
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};
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struct fuse_session;
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struct fuse_chan;
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struct fuse_pollhandle_t;
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typedef struct fuse_pollhandle_t fuse_pollhandle_t;
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/**
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* Create a FUSE mountpoint
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*
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* Returns a control file descriptor suitable for passing to
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* fuse_new()
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*
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* @param mountpoint the mount point path
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* @param args argument vector
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* @return the communication channel on success, NULL on failure
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*/
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struct fuse_chan *fuse_mount(const char *mountpoint,
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struct fuse_args *args);
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/**
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* Umount a FUSE mountpoint
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*
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* @param mountpoint the mount point path
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* @param ch the communication channel
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*/
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void fuse_unmount(const char *mountpoint, struct fuse_chan *ch);
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/**
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* Parse common options
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*
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* The following options are parsed:
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*
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* '-f' foreground
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* '-d' '-odebug' foreground, but keep the debug option
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* '-h' '--help' help
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* '-ho' help without header
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* '-ofsname=..' file system name, if not present, then set to the program
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* name
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*
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* All parameters may be NULL
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*
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* @param args argument vector
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* @param mountpoint the returned mountpoint, should be freed after use
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* @param foreground set to 1 if one of the relevant options is present
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* @return 0 on success, -1 on failure
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*/
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int fuse_parse_cmdline(struct fuse_args *args,
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char **mountpoint,
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int *foreground);
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/**
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* Go into the background
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*
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* @param foreground if true, stay in the foreground
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* @return 0 on success, -1 on failure
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*/
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int fuse_daemonize(int foreground);
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/**
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* Get the version of the library
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*
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* @return the version
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*/
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int fuse_version(void);
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/**
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* Destroy poll handle
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*
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* @param ph the poll handle
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*/
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void fuse_pollhandle_destroy(fuse_pollhandle_t *ph);
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/* ----------------------------------------------------------- *
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* Data buffer *
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* ----------------------------------------------------------- */
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/**
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* Buffer flags
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*/
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enum fuse_buf_flags {
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/**
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* Buffer contains a file descriptor
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*
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* If this flag is set, the .fd field is valid, otherwise the
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* .mem fields is valid.
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*/
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FUSE_BUF_IS_FD = (1 << 1),
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/**
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* Seek on the file descriptor
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*
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* If this flag is set then the .pos field is valid and is
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* used to seek to the given offset before performing
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* operation on file descriptor.
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*/
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FUSE_BUF_FD_SEEK = (1 << 2),
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/**
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* Retry operation on file descriptor
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*
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* If this flag is set then retry operation on file descriptor
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* until .size bytes have been copied or an error or EOF is
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* detected.
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*/
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FUSE_BUF_FD_RETRY = (1 << 3),
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};
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/**
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* Buffer copy flags
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*/
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enum fuse_buf_copy_flags {
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/**
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* Don't use splice(2)
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*
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* Always fall back to using read and write instead of
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* splice(2) to copy data from one file descriptor to another.
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*
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* If this flag is not set, then only fall back if splice is
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* unavailable.
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*/
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FUSE_BUF_NO_SPLICE = (1 << 1),
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/**
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* Force splice
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*
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* Always use splice(2) to copy data from one file descriptor
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* to another. If splice is not available, return -EINVAL.
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*/
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FUSE_BUF_FORCE_SPLICE = (1 << 2),
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/**
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* Try to move data with splice.
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*
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* If splice is used, try to move pages from the source to the
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* destination instead of copying. See documentation of
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* SPLICE_F_MOVE in splice(2) man page.
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*/
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FUSE_BUF_SPLICE_MOVE = (1 << 3),
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/**
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* Don't block on the pipe when copying data with splice
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*
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* Makes the operations on the pipe non-blocking (if the pipe
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* is full or empty). See SPLICE_F_NONBLOCK in the splice(2)
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* man page.
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*/
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FUSE_BUF_SPLICE_NONBLOCK= (1 << 4),
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};
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/**
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* Single data buffer
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*
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* Generic data buffer for I/O, extended attributes, etc... Data may
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* be supplied as a memory pointer or as a file descriptor
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*/
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struct fuse_buf {
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/**
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* Size of data in bytes
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*/
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size_t size;
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/**
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* Buffer flags
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*/
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enum fuse_buf_flags flags;
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/**
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* Memory pointer
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*
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* Used unless FUSE_BUF_IS_FD flag is set.
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*/
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void *mem;
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/**
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* File descriptor
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*
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* Used if FUSE_BUF_IS_FD flag is set.
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*/
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int fd;
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/**
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* File position
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*
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* Used if FUSE_BUF_FD_SEEK flag is set.
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*/
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off_t pos;
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};
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/**
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* Data buffer vector
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*
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* An array of data buffers, each containing a memory pointer or a
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* file descriptor.
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*
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* Allocate dynamically to add more than one buffer.
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*/
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struct fuse_bufvec {
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/**
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* Number of buffers in the array
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*/
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size_t count;
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/**
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* Index of current buffer within the array
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*/
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size_t idx;
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/**
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* Current offset within the current buffer
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*/
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size_t off;
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/**
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* Array of buffers
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*/
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struct fuse_buf buf[1];
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};
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/* Initialize bufvec with a single buffer of given size */
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#define FUSE_BUFVEC_INIT(size__) \
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((struct fuse_bufvec) { \
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/* .count= */ 1, \
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/* .idx = */ 0, \
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/* .off = */ 0, \
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/* .buf = */ { /* [0] = */ { \
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/* .size = */ (size__), \
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/* .flags = */ (enum fuse_buf_flags) 0, \
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/* .mem = */ NULL, \
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/* .fd = */ -1, \
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/* .pos = */ 0, \
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} } \
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} )
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/**
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* Get total size of data in a fuse buffer vector
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*
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* @param bufv buffer vector
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* @return size of data
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*/
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size_t fuse_buf_size(const struct fuse_bufvec *bufv);
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/**
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* Copy data from one buffer vector to another
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*
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* @param dst destination buffer vector
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* @param src source buffer vector
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* @param flags flags controlling the copy
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* @return actual number of bytes copied or -errno on error
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*/
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ssize_t fuse_buf_copy(struct fuse_bufvec *dst, struct fuse_bufvec *src,
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enum fuse_buf_copy_flags flags);
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/* ----------------------------------------------------------- *
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* Signal handling *
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* ----------------------------------------------------------- */
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/**
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* Exit session on HUP, TERM and INT signals and ignore PIPE signal
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*
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* Stores session in a global variable. May only be called once per
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* process until fuse_remove_signal_handlers() is called.
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*
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* @param se the session to exit
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* @return 0 on success, -1 on failure
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*/
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int fuse_set_signal_handlers(struct fuse_session *se);
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/**
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* Restore default signal handlers
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*
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* Resets global session. After this fuse_set_signal_handlers() may
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* be called again.
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*
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* @param se the same session as given in fuse_set_signal_handlers()
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*/
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void fuse_remove_signal_handlers(struct fuse_session *se);
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EXTERN_C_END
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#endif /* _FUSE_COMMON_H_ */
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