include/fuse_common.h

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU LGPLv2.
   6   See the file COPYING.LIB.
   7 */
   8
   9 /** @file */
  10
  11 #if !defined(_FUSE_H_) && !defined(_FUSE_LOWLEVEL_H_)
  12 #error "Never include <fuse_common.h> directly; use <fuse.h> or <fuse_lowlevel.h> instead."
  13 #endif
  14
  15 #ifndef _FUSE_COMMON_H_
  16 #define _FUSE_COMMON_H_
  17
  18 #include "fuse_opt.h"
  19 #include <stdint.h>
  20
  21 /** Major version of FUSE library interface */
  22 #define FUSE_MAJOR_VERSION 2
  23
  24 /** Minor version of FUSE library interface */
  25 #define FUSE_MINOR_VERSION 8
  26
  27 #define FUSE_MAKE_VERSION(maj, min)  ((maj) * 10 + (min))
  28 #define FUSE_VERSION FUSE_MAKE_VERSION(FUSE_MAJOR_VERSION, FUSE_MINOR_VERSION)
  29
  30 /* This interface uses 64 bit off_t */
  31 #if _FILE_OFFSET_BITS != 64
  32 #error Please add -D_FILE_OFFSET_BITS=64 to your compile flags!
  33 #endif
  34
  35 #ifdef __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 /**
  40  * Information about open files
  41  *
  42  * Changed in version 2.5
  43  */
  44 struct fuse_file_info {
  45         /** Open flags.  Available in open() and release() */
  46         int flags;
  47
  48         /** Old file handle, don't use */
  49         unsigned long fh_old;
  50
  51         /** In case of a write operation indicates if this was caused by a
  52             writepage */
  53         int writepage;
  54
  55         /** Can be filled in by open, to use direct I/O on this file.
  56             Introduced in version 2.4 */
  57         unsigned int direct_io : 1;
  58
  59         /** Can be filled in by open, to indicate, that cached file data
  60             need not be invalidated.  Introduced in version 2.4 */
  61         unsigned int keep_cache : 1;
  62
  63         /** Indicates a flush operation.  Set in flush operation, also
  64             maybe set in highlevel lock operation and lowlevel release
  65             operation.  Introduced in version 2.6 */
  66         unsigned int flush : 1;
  67
  68         /** Can be filled in by open, to indicate that the file is not
  69             seekable.  Introduced in version 2.8 */
  70         unsigned int nonseekable : 1;
  71
  72         /** Padding.  Do not use*/
  73         unsigned int padding : 28;
  74
  75         /** File handle.  May be filled in by filesystem in open().
  76             Available in all other file operations */
  77         uint64_t fh;
  78
  79         /** Lock owner id.  Available in locking operations and flush */
  80         uint64_t lock_owner;
  81 };
  82
  83 /**
  84  * Capability bits for 'fuse_conn_info.capable' and 'fuse_conn_info.want'
  85  *
  86  * FUSE_CAP_ASYNC_READ: filesystem supports asynchronous read requests
  87  * FUSE_CAP_POSIX_LOCKS: filesystem supports "remote" locking
  88  * FUSE_CAP_ATOMIC_O_TRUNC: filesystem handles the O_TRUNC open flag
  89  * FUSE_CAP_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
  90  * FUSE_CAP_BIG_WRITES: filesystem can handle write size larger than 4kB
  91  * FUSE_CAP_DONT_MASK: don't apply umask to file mode on create operations
  92  */
  93 #define FUSE_CAP_ASYNC_READ     (1 << 0)
  94 #define FUSE_CAP_POSIX_LOCKS    (1 << 1)
  95 #define FUSE_CAP_ATOMIC_O_TRUNC (1 << 3)
  96 #define FUSE_CAP_EXPORT_SUPPORT (1 << 4)
  97 #define FUSE_CAP_BIG_WRITES     (1 << 5)
  98 #define FUSE_CAP_DONT_MASK      (1 << 6)
  99
 100 /**
 101  * Ioctl flags
 102  *
 103  * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
 104  * FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
 105  * FUSE_IOCTL_RETRY: retry with new iovecs
 106  *
 107  * FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
 108  */
 109 #define FUSE_IOCTL_COMPAT       (1 << 0)
 110 #define FUSE_IOCTL_UNRESTRICTED (1 << 1)
 111 #define FUSE_IOCTL_RETRY        (1 << 2)
 112
 113 #define FUSE_IOCTL_MAX_IOV      256
 114
 115 /**
 116  * Connection information, passed to the ->init() method
 117  *
 118  * Some of the elements are read-write, these can be changed to
 119  * indicate the value requested by the filesystem.  The requested
 120  * value must usually be smaller than the indicated value.
 121  */
 122 struct fuse_conn_info {
 123         /**
 124          * Major version of the protocol (read-only)
 125          */
 126         unsigned proto_major;
 127
 128         /**
 129          * Minor version of the protocol (read-only)
 130          */
 131         unsigned proto_minor;
 132
 133         /**
 134          * Is asynchronous read supported (read-write)
 135          */
 136         unsigned async_read;
 137
 138         /**
 139          * Maximum size of the write buffer
 140          */
 141         unsigned max_write;
 142
 143         /**
 144          * Maximum readahead
 145          */
 146         unsigned max_readahead;
 147
 148         /**
 149          * Capability flags, that the kernel supports
 150          */
 151         unsigned capable;
 152
 153         /**
 154          * Capability flags, that the filesystem wants to enable
 155          */
 156         unsigned want;
 157
 158         /**
 159          * For future use.
 160          */
 161         unsigned reserved[25];
 162 };
 163
 164 struct fuse_session;
 165 struct fuse_chan;
 166 struct fuse_pollhandle;
 167
 168 /**
 169  * Create a FUSE mountpoint
 170  *
 171  * Returns a control file descriptor suitable for passing to
 172  * fuse_new()
 173  *
 174  * @param mountpoint the mount point path
 175  * @param args argument vector
 176  * @return the communication channel on success, NULL on failure
 177  */
 178 struct fuse_chan *fuse_mount(const char *mountpoint, struct fuse_args *args);
 179
 180 /**
 181  * Umount a FUSE mountpoint
 182  *
 183  * @param mountpoint the mount point path
 184  * @param ch the communication channel
 185  */
 186 void fuse_unmount(const char *mountpoint, struct fuse_chan *ch);
 187
 188 /**
 189  * Parse common options
 190  *
 191  * The following options are parsed:
 192  *
 193  *   '-f'            foreground
 194  *   '-d' '-odebug'  foreground, but keep the debug option
 195  *   '-s'            single threaded
 196  *   '-h' '--help'   help
 197  *   '-ho'           help without header
 198  *   '-ofsname=..'   file system name, if not present, then set to the program
 199  *                   name
 200  *
 201  * All parameters may be NULL
 202  *
 203  * @param args argument vector
 204  * @param mountpoint the returned mountpoint, should be freed after use
 205  * @param multithreaded set to 1 unless the '-s' option is present
 206  * @param foreground set to 1 if one of the relevant options is present
 207  * @return 0 on success, -1 on failure
 208  */
 209 int fuse_parse_cmdline(struct fuse_args *args, char **mountpoint,
 210                        int *multithreaded, int *foreground);
 211
 212 /**
 213  * Go into the background
 214  *
 215  * @param foreground if true, stay in the foreground
 216  * @return 0 on success, -1 on failure
 217  */
 218 int fuse_daemonize(int foreground);
 219
 220 /**
 221  * Get the version of the library
 222  *
 223  * @return the version
 224  */
 225 int fuse_version(void);
 226
 227 /**
 228  * Destroy poll handle
 229  *
 230  * @param ph the poll handle
 231  */
 232 void fuse_pollhandle_destroy(struct fuse_pollhandle *ph);
 233
 234 /* ----------------------------------------------------------- *
 235  * Signal handling                                             *
 236  * ----------------------------------------------------------- */
 237
 238 /**
 239  * Exit session on HUP, TERM and INT signals and ignore PIPE signal
 240  *
 241  * Stores session in a global variable.  May only be called once per
 242  * process until fuse_remove_signal_handlers() is called.
 243  *
 244  * @param se the session to exit
 245  * @return 0 on success, -1 on failure
 246  */
 247 int fuse_set_signal_handlers(struct fuse_session *se);
 248
 249 /**
 250  * Restore default signal handlers
 251  *
 252  * Resets global session.  After this fuse_set_signal_handlers() may
 253  * be called again.
 254  *
 255  * @param se the same session as given in fuse_set_signal_handlers()
 256  */
 257 void fuse_remove_signal_handlers(struct fuse_session *se);
 258
 259 /* ----------------------------------------------------------- *
 260  * Compatibility stuff                                         *
 261  * ----------------------------------------------------------- */
 262
 263 #if FUSE_USE_VERSION < 26
 264 #    ifdef __FreeBSD__
 265 #        if FUSE_USE_VERSION < 25
 266 #            error On FreeBSD API version 25 or greater must be used
 267 #        endif
 268 #    endif
 269 #    include "fuse_common_compat.h"
 270 #    undef FUSE_MINOR_VERSION
 271 #    undef fuse_main
 272 #    define fuse_unmount fuse_unmount_compat22
 273 #    if FUSE_USE_VERSION == 25
 274 #        define FUSE_MINOR_VERSION 5
 275 #        define fuse_mount fuse_mount_compat25
 276 #    elif FUSE_USE_VERSION == 24 || FUSE_USE_VERSION == 22
 277 #        define FUSE_MINOR_VERSION 4
 278 #        define fuse_mount fuse_mount_compat22
 279 #    elif FUSE_USE_VERSION == 21
 280 #        define FUSE_MINOR_VERSION 1
 281 #        define fuse_mount fuse_mount_compat22
 282 #    elif FUSE_USE_VERSION == 11
 283 #        warning Compatibility with API version 11 is deprecated
 284 #        undef FUSE_MAJOR_VERSION
 285 #        define FUSE_MAJOR_VERSION 1
 286 #        define FUSE_MINOR_VERSION 1
 287 #        define fuse_mount fuse_mount_compat1
 288 #    else
 289 #        error Compatibility with API version other than 21, 22, 24, 25 and 11 not supported
 290 #    endif
 291 #endif
 292
 293 #ifdef __cplusplus
 294 }
 295 #endif
 296
 297 #endif /* _FUSE_COMMON_H_ */