| /* |
| FUSE: Filesystem in Userspace |
| Copyright (C) 2001-2004 Miklos Szeredi <miklos@szeredi.hu> |
| |
| This program can be distributed under the terms of the GNU LGPL. |
| See the file COPYING.LIB. |
| */ |
| |
| #ifndef _FUSE_H_ |
| #define _FUSE_H_ |
| |
| /* This file defines the library interface of FUSE */ |
| |
| /* IMPORTANT: you should define FUSE_USE_VERSION before including this |
| header. To use the new API define it to 22 (recommended for any |
| new application), to use the old API define it to 21 (this is the |
| default), to use the even older 1.X API define it to 11. */ |
| |
| #ifndef FUSE_USE_VERSION |
| #define FUSE_USE_VERSION 21 |
| #endif |
| |
| /** Major version of FUSE library interface */ |
| #define FUSE_MAJOR_VERSION 2 |
| |
| /** Minor version of FUSE library interface */ |
| #define FUSE_MINOR_VERSION 2 |
| |
| /* This interface uses 64 bit off_t */ |
| #if _FILE_OFFSET_BITS != 64 |
| #error Please add -D_FILE_OFFSET_BITS=64 to your compile flags! |
| #endif |
| |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <sys/statfs.h> |
| #include <utime.h> |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /* ----------------------------------------------------------- * |
| * Basic FUSE API * |
| * ----------------------------------------------------------- */ |
| |
| /** Handle for a FUSE filesystem */ |
| struct fuse; |
| |
| /** Handle for a getdir() operation */ |
| typedef struct fuse_dirhandle *fuse_dirh_t; |
| |
| /** Function to add an entry in a getdir() operation |
| * |
| * @param h the handle passed to the getdir() operation |
| * @param name the file name of the directory entry |
| * @param type the file type (0 if unknown) see <dirent.h> |
| * @param ino the inode number, ignored if "use_ino" mount option is |
| * not specified |
| * @return 0 on success, -errno on error |
| */ |
| typedef int (*fuse_dirfil_t) (fuse_dirh_t h, const char *name, int type, |
| ino_t ino); |
| |
| /** Information about open files */ |
| struct fuse_file_info { |
| /** Open flags. Available in open() and release() */ |
| int flags; |
| |
| /** File handle. May be filled in by filesystem in open(). |
| Available in all other file operations */ |
| unsigned long fh; |
| |
| /** In case of a write operation indicates if this was caused by a |
| writepage */ |
| int writepage; |
| }; |
| |
| /** |
| * The file system operations: |
| * |
| * Most of these should work very similarly to the well known UNIX |
| * file system operations. A major exception is that instead of |
| * returning an error in 'errno', the operation should return the |
| * negated error value (-errno) directly. |
| */ |
| struct fuse_operations { |
| /** Get file attributes. |
| * |
| * Similar to stat(). The 'st_dev' and 'st_blksize' fields are |
| * ignored. The 'st_ino' field is ignored except if the 'use_ino' |
| * mount option is given. |
| */ |
| int (*getattr) (const char *, struct stat *); |
| |
| /** Read the target of a symbolic link |
| * |
| * The buffer should be filled with a null terminated string. The |
| * buffer size argument includes the space for the terminating |
| * null character. If the linkname is too long to fit in the |
| * buffer, it should be truncated. The return value should be 0 |
| * for success. |
| */ |
| int (*readlink) (const char *, char *, size_t); |
| |
| /** Read the contents of a directory |
| * |
| * This operation is the opendir(), readdir(), ..., closedir() |
| * sequence in one call. For each directory entry the filldir |
| * function should be called. |
| */ |
| int (*getdir) (const char *, fuse_dirh_t, fuse_dirfil_t); |
| |
| /** Create a file node |
| * |
| * There is no create() operation, mknod() will be called for |
| * creation of all non-directory, non-symlink nodes. |
| */ |
| int (*mknod) (const char *, mode_t, dev_t); |
| |
| /** Create a directory */ |
| int (*mkdir) (const char *, mode_t); |
| |
| /** Remove a file */ |
| int (*unlink) (const char *); |
| |
| /** Remove a directory */ |
| int (*rmdir) (const char *); |
| |
| /** Create a symbolic link */ |
| int (*symlink) (const char *, const char *); |
| |
| /** Rename a file */ |
| int (*rename) (const char *, const char *); |
| |
| /** Create a hard link to a file */ |
| int (*link) (const char *, const char *); |
| |
| /** Change the permission bits of a file */ |
| int (*chmod) (const char *, mode_t); |
| |
| /** Change the owner and group of a file */ |
| int (*chown) (const char *, uid_t, gid_t); |
| |
| /** Change the size of a file */ |
| int (*truncate) (const char *, off_t); |
| |
| /** Change the access and/or modification times of a file */ |
| int (*utime) (const char *, struct utimbuf *); |
| |
| /** File open operation |
| * |
| * No creation, or trunctation flags (O_CREAT, O_EXCL, O_TRUNC) |
| * will be passed to open(). Open should check if the operation |
| * is permitted for the given flags. Optionally open may also |
| * return an arbitary filehandle in the fuse_file_info structure, |
| * which will be passed to all file operations. |
| */ |
| int (*open) (const char *, struct fuse_file_info *); |
| |
| /** Read data from an open file |
| * |
| * Read should return exactly the number of bytes requested except |
| * on EOF or error, otherwise the rest of the data will be |
| * substituted with zeroes. An exception to this is when the |
| * 'direct_io' mount option is specified, in which case the return |
| * value of the read system call will reflect the return value of |
| * this operation. |
| */ |
| int (*read) (const char *, char *, size_t, off_t, struct fuse_file_info *); |
| |
| /** Write data to an open file |
| * |
| * Write should return exactly the number of bytes requested |
| * except on error. An exception to this is when the 'direct_io' |
| * mount option is specified (see read operation). |
| */ |
| int (*write) (const char *, const char *, size_t, off_t, |
| struct fuse_file_info *); |
| |
| /** Get file system statistics |
| * |
| * The 'f_type' and 'f_fsid' fields are ignored |
| */ |
| int (*statfs) (const char *, struct statfs *); |
| |
| /** Possibly flush cached data |
| * |
| * BIG NOTE: This is not equivalent to fsync(). It's not a |
| * request to sync dirty data, and can safely be ignored. |
| * |
| * Flush is called on each close() of a file descriptor. So if a |
| * filesystem wants to return write errors in close() and the file |
| * has cached dirty data, this is a good place to write back data |
| * and return any errors. |
| * |
| * NOTE: The flush() method may be called more than once for each |
| * open(). This happens if more than one file descriptor refers |
| * to an opened file due to dup(), dup2() or fork() calls. It is |
| * not possible to determine if a flush is final, so each flush |
| * should be treated equally. Multiple write-flush sequences are |
| * relatively rare, so this shouldn't be a problem. |
| */ |
| int (*flush) (const char *, struct fuse_file_info *); |
| |
| /** Release an open file |
| * |
| * Release is called when there are no more references to an open |
| * file: all file descriptors are closed and all memory mappings |
| * are unmapped. |
| * |
| * For every open() call there will be exactly one release() call |
| * with the same flags. It is possible to have a file opened more |
| * than once, in which case only the last release will mean, that |
| * no more reads/writes will happen on the file. The return value |
| * of release is ignored. Implementing this method is optional. |
| */ |
| int (*release) (const char *, struct fuse_file_info *); |
| |
| /** Synchronize file contents |
| * |
| * If the datasync parameter is non-zero, then only the user data |
| * should be flushed, not the meta data. |
| */ |
| int (*fsync) (const char *, int, struct fuse_file_info *); |
| |
| /** Set extended attributes */ |
| int (*setxattr) (const char *, const char *, const char *, size_t, int); |
| |
| /** Get extended attributes */ |
| int (*getxattr) (const char *, const char *, char *, size_t); |
| |
| /** List extended attributes */ |
| int (*listxattr) (const char *, char *, size_t); |
| |
| /** Remove extended attributes */ |
| int (*removexattr) (const char *, const char *); |
| }; |
| |
| /** Extra context that may be needed by some filesystems |
| * |
| * The uid, gid and pid fields are not filled in case of a writepage |
| * operation. |
| */ |
| struct fuse_context { |
| /** Pointer to the fuse object */ |
| struct fuse *fuse; |
| |
| /** User ID of the calling process */ |
| uid_t uid; |
| |
| /** Group ID of the calling process */ |
| gid_t gid; |
| |
| /** Thread ID of the calling process */ |
| pid_t pid; |
| |
| /** Currently unused */ |
| void *private_data; |
| }; |
| |
| /* |
| * Main function of FUSE. |
| * |
| * This is for the lazy. This is all that has to be called from the |
| * main() function. |
| * |
| * This function does the following: |
| * - parses command line options (-d -s and -h) |
| * - passes relevant mount options to the fuse_mount() |
| * - installs signal handlers for INT, HUP, TERM and PIPE |
| * - registers an exit handler to unmount the filesystem on program exit |
| * - creates a fuse handle |
| * - registers the operations |
| * - calls either the single-threaded or the multi-threaded event loop |
| * |
| * Note: this is currently implemented as a macro. |
| * |
| * @param argc the argument counter passed to the main() function |
| * @param argv the argument vector passed to the main() function |
| * @param op the file system operation |
| * @return 0 on success, nonzero on failure |
| */ |
| /* |
| int fuse_main(int argc, char *argv[], const struct fuse_operations *op); |
| */ |
| #define fuse_main(argc, argv, op) \ |
| fuse_main_real(argc, argv, op, sizeof(*(op))) |
| |
| /* ----------------------------------------------------------- * |
| * More detailed API * |
| * ----------------------------------------------------------- */ |
| |
| /* |
| * Create a FUSE mountpoint |
| * |
| * Returns a control file descriptor suitable for passing to |
| * fuse_new() |
| * |
| * @param mountpoint the mount point path |
| * @param opts a comma separated list of mount options. Can be NULL. |
| * @return the control file descriptor on success, -1 on failure |
| */ |
| int fuse_mount(const char *mountpoint, const char *opts); |
| |
| /* |
| * Umount a FUSE mountpoint |
| * |
| * @param mountpoint the mount point path |
| */ |
| void fuse_unmount(const char *mountpoint); |
| |
| /** |
| * Create a new FUSE filesystem. |
| * |
| * @param fd the control file descriptor |
| * @param opts mount options to be used by the library |
| * @param op the operations |
| * @param op_size the size of the fuse_operations structure |
| * @return the created FUSE handle |
| */ |
| struct fuse *fuse_new(int fd, const char *opts, |
| const struct fuse_operations *op, size_t op_size); |
| |
| /** |
| * Destroy the FUSE handle. |
| * |
| * The filesystem is not unmounted. |
| * |
| * @param f the FUSE handle |
| */ |
| void fuse_destroy(struct fuse *f); |
| |
| /** |
| * FUSE event loop. |
| * |
| * Requests from the kernel are processed, and the apropriate |
| * operations are called. |
| * |
| * @param f the FUSE handle |
| * @return 0 if no error occured, -1 otherwise |
| */ |
| int fuse_loop(struct fuse *f); |
| |
| /** |
| * Exit from event loop |
| * |
| * @param f the FUSE handle |
| */ |
| void fuse_exit(struct fuse *f); |
| |
| /** |
| * FUSE event loop with multiple threads |
| * |
| * Requests from the kernel are processed, and the apropriate |
| * operations are called. Request are processed in parallel by |
| * distributing them between multiple threads. |
| * |
| * Calling this function requires the pthreads library to be linked to |
| * the application. |
| * |
| * @param f the FUSE handle |
| * @return 0 if no error occured, -1 otherwise |
| */ |
| int fuse_loop_mt(struct fuse *f); |
| |
| /** |
| * Get the current context |
| * |
| * The context is only valid for the duration of a filesystem |
| * operation, and thus must not be stored and used later. |
| * |
| * @param f the FUSE handle |
| * @return the context |
| */ |
| struct fuse_context *fuse_get_context(void); |
| |
| /** |
| * Invalidate cached data of a file. |
| * |
| * Useful if the 'kernel_cache' mount option is given, since in that |
| * case the cache is not invalidated on file open. |
| * |
| * @return 0 on success or -errno on failure |
| */ |
| int fuse_invalidate(struct fuse *f, const char *path); |
| |
| /** |
| * Check whether a mount option should be passed to the kernel or the |
| * library |
| * |
| * @param opt the option to check |
| * @return 1 if it is a library option, 0 otherwise |
| */ |
| int fuse_is_lib_option(const char *opt); |
| |
| /** |
| * The real main function |
| * |
| * Do not call this directly, use fuse_main() |
| */ |
| int fuse_main_real(int argc, char *argv[], const struct fuse_operations *op, |
| size_t op_size); |
| |
| /* ----------------------------------------------------------- * |
| * Advanced API for event handling, don't worry about this... * |
| * ----------------------------------------------------------- */ |
| |
| /** Structure containing a raw command */ |
| struct fuse_cmd; |
| |
| /** Function type used to process commands */ |
| typedef void (*fuse_processor_t)(struct fuse *, struct fuse_cmd *, void *); |
| |
| /** This is the part of fuse_main() before the event loop */ |
| struct fuse *fuse_setup(int argc, char *argv[], |
| const struct fuse_operations *op, size_t op_size, |
| char **mountpoint, int *multithreaded, int *fd); |
| |
| /** This is the part of fuse_main() after the event loop */ |
| void fuse_teardown(struct fuse *fuse, int fd, char *mountpoint); |
| |
| /** Read a single command. If none are read, return NULL */ |
| struct fuse_cmd *fuse_read_cmd(struct fuse *f); |
| |
| /** Process a single command */ |
| void fuse_process_cmd(struct fuse *f, struct fuse_cmd *cmd); |
| |
| /** Multi threaded event loop, which calls the custom command |
| processor function */ |
| int fuse_loop_mt_proc(struct fuse *f, fuse_processor_t proc, void *data); |
| |
| /** Return the exited flag, which indicates if fuse_exit() has been |
| called */ |
| int fuse_exited(struct fuse* f); |
| |
| /** Set function which can be used to get the current context */ |
| void fuse_set_getcontext_func(struct fuse_context *(*func)(void)); |
| |
| /* ----------------------------------------------------------- * |
| * Compatibility stuff * |
| * ----------------------------------------------------------- */ |
| |
| #if FUSE_USE_VERSION == 21 || FUSE_USE_VERSION == 11 |
| # include <fuse_compat.h> |
| # define fuse_dirfil_t fuse_dirfil_t_compat |
| # define __fuse_read_cmd fuse_read_cmd |
| # define __fuse_process_cmd fuse_process_cmd |
| # define __fuse_loop_mt fuse_loop_mt_proc |
| # undef fuse_main |
| # undef FUSE_MINOR_VERSION |
| # undef FUSE_MAJOR_VERSION |
| # if FUSE_USE_VERSION == 21 |
| # define FUSE_MAJOR_VERSION 2 |
| # define FUSE_MINOR_VERSION 1 |
| # define fuse_operations fuse_operations_compat2 |
| # define fuse_main fuse_main_compat2 |
| # define fuse_new fuse_new_compat2 |
| # define __fuse_setup fuse_setup_compat2 |
| # define __fuse_teardown fuse_teardown |
| # define __fuse_exited fuse_exited |
| # define __fuse_set_getcontext_func fuse_set_getcontext_func |
| # else |
| # define FUSE_MAJOR_VERSION 1 |
| # define FUSE_MINOR_VERSION 1 |
| # define fuse_statfs fuse_statfs_compat1 |
| # define fuse_operations fuse_operations_compat1 |
| # define fuse_main fuse_main_compat1 |
| # define fuse_new fuse_new_compat1 |
| # define fuse_mount fuse_mount_compat1 |
| # define FUSE_DEBUG FUSE_DEBUG_COMPAT1 |
| # endif |
| #elif FUSE_USE_VERSION < 22 |
| # error Compatibility with API version other than 21 and 11 not supported |
| #endif |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* _FUSE_H_ */ |