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diff --git a/include/fuse-lite/fuse.h b/include/fuse-lite/fuse.h new file mode 100755 index 0000000..1b3291a --- a/dev/null +++ b/include/fuse-lite/fuse.h @@ -0,0 +1,654 @@ +/* + 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. +*/ + +#ifndef _FUSE_H_ +#define _FUSE_H_ + +/** @file + * + * This file defines the library interface of FUSE + */ + +#include "fuse_common.h" + +#include <fcntl.h> +#include <time.h> +#include <utime.h> +#ifdef HAVE_SYS_TYPES_H +#include <sys/types.h> +#endif + +#include <sys/stat.h> + +#if HAVE_SYS_STATVFS_H +#include <sys/statvfs.h> +#endif + +#ifdef __cplusplus +extern "C" { +#endif + +/* ----------------------------------------------------------- * + * Basic FUSE API * + * ----------------------------------------------------------- */ + +/** Handle for a FUSE filesystem */ +struct fuse; + +/** Structure containing a raw command */ +struct fuse_cmd; + +/** Function to add an entry in a readdir() operation + * + * @param buf the buffer passed to the readdir() operation + * @param name the file name of the directory entry + * @param stat file attributes, can be NULL + * @param off offset of the next entry or zero + * @return 1 if buffer is full, zero otherwise + */ +typedef int (*fuse_fill_dir_t) (void *buf, const char *name, + const struct stat *stbuf, off_t off); + +/** + * 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. + * + * All methods are optional, but some are essential for a useful + * filesystem (e.g. getattr). Open, flush, release, fsync, opendir, + * releasedir, fsyncdir, access, create, ftruncate, fgetattr, lock, + * init and destroy are special purpose methods, without which a full + * featured filesystem can still be implemented. + * + * Almost all operations take a path which can be of any length. + * + * Changed in fuse 2.8.0 (regardless of API version) + * Previously, paths were limited to a length of PATH_MAX. + */ + +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); + + /** Create a file node + * + * This is called for creation of all non-directory, non-symlink + * nodes. If the filesystem defines a create() method, then for + * regular files that will be called instead. + */ + int (*mknod) (const char *, mode_t, dev_t); + + /** Create a directory + * + * Note that the mode argument may not have the type specification + * bits set, i.e. S_ISDIR(mode) can be false. To obtain the + * correct directory type bits use mode|S_IFDIR + * */ + 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 + * + * Deprecated, use utimens() instead. + */ + int (*utime) (const char *, struct utimbuf *); + + /** File open operation + * + * No creation (O_CREAT, O_EXCL) and by default also no + * truncation (O_TRUNC) flags will be passed to open(). If an + * application specifies O_TRUNC, fuse first calls truncate() + * and then open(). Only if 'atomic_o_trunc' has been + * specified and kernel version is 2.6.24 or later, O_TRUNC is + * passed on to open. + * + * Unless the 'default_permissions' mount option is given, + * open should check if the operation is permitted for the + * given flags. Optionally open may also return an arbitrary + * filehandle in the fuse_file_info structure, which will be + * passed to all file operations. + * + * Changed in version 2.2 + */ + 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. + * + * Changed in version 2.2 + */ + 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). + * + * Changed in version 2.2 + */ + int (*write) (const char *, const char *, size_t, off_t, + struct fuse_file_info *); + + /** Get file system statistics + * + * The 'f_frsize', 'f_favail', 'f_fsid' and 'f_flag' fields are ignored + * + * Replaced 'struct statfs' parameter with 'struct statvfs' in + * version 2.5 + */ +#if HAVE_SYS_STATVFS_H + + int (*statfs) (const char *, struct statvfs *); + +#endif + /** Possibly flush cached data + * + * BIG NOTE: This is not equivalent to fsync(). It's not a + * request to sync dirty data. + * + * 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. Since many applications ignore close() + * errors this is not always useful. + * + * 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. + * + * Filesystems shouldn't assume that flush will always be called + * after some writes, or that if will be called at all. + * + * Changed in version 2.2 + */ + 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 and file descriptor. 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. + * + * Changed in version 2.2 + */ + 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. + * + * Changed in version 2.2 + */ + 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 *); + + /** Open directory + * + * This method should check if the open operation is permitted for + * this directory + * + * Introduced in version 2.3 + */ + int (*opendir) (const char *, struct fuse_file_info *); + + /** Read directory + * + * The filesystem may choose between two modes of operation: + * + * 1) The readdir implementation ignores the offset parameter, and + * passes zero to the filler function's offset. The filler + * function will not return '1' (unless an error happens), so the + * whole directory is read in a single readdir operation. + * + * 2) The readdir implementation keeps track of the offsets of the + * directory entries. It uses the offset parameter and always + * passes non-zero offset to the filler function. When the buffer + * is full (or an error happens) the filler function will return + * '1'. + * + * Introduced in version 2.3 + */ + int (*readdir) (const char *, void *, fuse_fill_dir_t, off_t, + struct fuse_file_info *); + + /** Release directory + * + * Introduced in version 2.3 + */ + int (*releasedir) (const char *, struct fuse_file_info *); + + /** Synchronize directory contents + * + * If the datasync parameter is non-zero, then only the user data + * should be flushed, not the meta data + * + * Introduced in version 2.3 + */ + int (*fsyncdir) (const char *, int, struct fuse_file_info *); + + /** + * Initialize filesystem + * + * The return value will passed in the private_data field of + * fuse_context to all file operations and as a parameter to the + * destroy() method. + * + * Introduced in version 2.3 + * Changed in version 2.6 + */ + void *(*init) (struct fuse_conn_info *conn); + + /** + * Clean up filesystem + * + * Called on filesystem exit. + * + * Introduced in version 2.3 + */ + void (*destroy) (void *); + + /** + * Check file access permissions + * + * This will be called for the access() system call. If the + * 'default_permissions' mount option is given, this method is not + * called. + * + * This method is not called under Linux kernel versions 2.4.x + * + * Introduced in version 2.5 + */ + int (*access) (const char *, int); + + /** + * Create and open a file + * + * If the file does not exist, first create it with the specified + * mode, and then open it. + * + * If this method is not implemented or under Linux kernel + * versions earlier than 2.6.15, the mknod() and open() methods + * will be called instead. + * + * Introduced in version 2.5 + */ + int (*create) (const char *, mode_t, struct fuse_file_info *); + + /** + * Change the size of an open file + * + * This method is called instead of the truncate() method if the + * truncation was invoked from an ftruncate() system call. + * + * If this method is not implemented or under Linux kernel + * versions earlier than 2.6.15, the truncate() method will be + * called instead. + * + * Introduced in version 2.5 + */ + int (*ftruncate) (const char *, off_t, struct fuse_file_info *); + + /** + * Get attributes from an open file + * + * This method is called instead of the getattr() method if the + * file information is available. + * + * Currently this is only called after the create() method if that + * is implemented (see above). Later it may be called for + * invocations of fstat() too. + * + * Introduced in version 2.5 + */ + int (*fgetattr) (const char *, struct stat *, struct fuse_file_info *); + + /** + * Perform POSIX file locking operation + * + * The cmd argument will be either F_GETLK, F_SETLK or F_SETLKW. + * + * For the meaning of fields in 'struct flock' see the man page + * for fcntl(2). The l_whence field will always be set to + * SEEK_SET. + * + * For checking lock ownership, the 'fuse_file_info->owner' + * argument must be used. + * + * For F_GETLK operation, the library will first check currently + * held locks, and if a conflicting lock is found it will return + * information without calling this method. This ensures, that + * for local locks the l_pid field is correctly filled in. The + * results may not be accurate in case of race conditions and in + * the presence of hard links, but it's unlikly that an + * application would rely on accurate GETLK results in these + * cases. If a conflicting lock is not found, this method will be + * called, and the filesystem may fill out l_pid by a meaningful + * value, or it may leave this field zero. + * + * For F_SETLK and F_SETLKW the l_pid field will be set to the pid + * of the process performing the locking operation. + * + * Note: if this method is not implemented, the kernel will still + * allow file locking to work locally. Hence it is only + * interesting for network filesystems and similar. + * + * Introduced in version 2.6 + */ + int (*lock) (const char *, struct fuse_file_info *, int cmd, + struct flock *); + + /** + * Change the access and modification times of a file with + * nanosecond resolution + * + * Introduced in version 2.6 + */ + int (*utimens) (const char *, const struct timespec tv[2]); + + /** + * Map block index within file to block index within device + * + * Note: This makes sense only for block device backed filesystems + * mounted with the 'blkdev' option + * + * Introduced in version 2.6 + */ + int (*bmap) (const char *, size_t blocksize, uint64_t *idx); + unsigned int flag_nullpath_ok : 1; + + /** + * Flag indicating that the filesystem accepts special + * UTIME_NOW and UTIME_OMIT values in its utimens operation. + */ + unsigned int flag_utime_omit_ok : 1; + + /** + * Reserved flags, don't set + */ + unsigned int flag_reserved : 30; + +}; + +/** 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; + + /** Private filesystem data */ + void *private_data; + +#ifdef POSIXACLS + /** Umask of the calling process (introduced in version 2.8) */ + mode_t umask; +#endif +}; + +/* ----------------------------------------------------------- * + * More detailed API * + * ----------------------------------------------------------- */ + +/** + * Create a new FUSE filesystem. + * + * @param ch the communication channel + * @param args argument vector + * @param op the filesystem operations + * @param op_size the size of the fuse_operations structure + * @param user_data user data supplied in the context during the init() method + * @return the created FUSE handle + */ +struct fuse *fuse_new(struct fuse_chan *ch, struct fuse_args *args, + const struct fuse_operations *op, size_t op_size, + void *user_data); + +/** + * Destroy the FUSE handle. + * + * The communication channel attached to the handle is also destroyed. + * + * NOTE: This function does not unmount the filesystem. If this is + * needed, call fuse_unmount() before calling this function. + * + * @param f the FUSE handle + */ +void fuse_destroy(struct fuse *f); + +/** + * FUSE event loop. + * + * Requests from the kernel are processed, and the appropriate + * operations are called. + * + * @param f the FUSE handle + * @return 0 if no error occurred, -1 otherwise + */ +int fuse_loop(struct fuse *f); + +/** + * Exit from event loop + * + * @param f the FUSE handle + */ +void fuse_exit(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. + * + * @return the context + */ +struct fuse_context *fuse_get_context(void); + +/** + * Check if a request has already been interrupted + * + * @param req request handle + * @return 1 if the request has been interrupted, 0 otherwise + */ +int fuse_interrupted(void); + +/* + * Stacking API + */ + +/** + * Fuse filesystem object + * + * This is opaque object represents a filesystem layer + */ +struct fuse_fs; + +/* + * These functions call the relevant filesystem operation, and return + * the result. + * + * If the operation is not defined, they return -ENOSYS, with the + * exception of fuse_fs_open, fuse_fs_release, fuse_fs_opendir, + * fuse_fs_releasedir and fuse_fs_statfs, which return 0. + */ + +int fuse_fs_getattr(struct fuse_fs *fs, const char *path, struct stat *buf); +int fuse_fs_fgetattr(struct fuse_fs *fs, const char *path, struct stat *buf, + struct fuse_file_info *fi); +int fuse_fs_rename(struct fuse_fs *fs, const char *oldpath, + const char *newpath); +int fuse_fs_unlink(struct fuse_fs *fs, const char *path); +int fuse_fs_rmdir(struct fuse_fs *fs, const char *path); +int fuse_fs_symlink(struct fuse_fs *fs, const char *linkname, + const char *path); +int fuse_fs_link(struct fuse_fs *fs, const char *oldpath, const char *newpath); +int fuse_fs_release(struct fuse_fs *fs, const char *path, + struct fuse_file_info *fi); +int fuse_fs_open(struct fuse_fs *fs, const char *path, + struct fuse_file_info *fi); +int fuse_fs_read(struct fuse_fs *fs, const char *path, char *buf, size_t size, + off_t off, struct fuse_file_info *fi); +int fuse_fs_write(struct fuse_fs *fs, const char *path, const char *buf, + size_t size, off_t off, struct fuse_file_info *fi); +int fuse_fs_fsync(struct fuse_fs *fs, const char *path, int datasync, + struct fuse_file_info *fi); +int fuse_fs_flush(struct fuse_fs *fs, const char *path, + struct fuse_file_info *fi); + +#if HAVE_SYS_STATVFS_H +int fuse_fs_statfs(struct fuse_fs *fs, const char *path, struct statvfs *buf); +#endif + +int fuse_fs_opendir(struct fuse_fs *fs, const char *path, + struct fuse_file_info *fi); +int fuse_fs_readdir(struct fuse_fs *fs, const char *path, void *buf, + fuse_fill_dir_t filler, off_t off, + struct fuse_file_info *fi); +int fuse_fs_fsyncdir(struct fuse_fs *fs, const char *path, int datasync, + struct fuse_file_info *fi); +int fuse_fs_releasedir(struct fuse_fs *fs, const char *path, + struct fuse_file_info *fi); +int fuse_fs_create(struct fuse_fs *fs, const char *path, mode_t mode, + struct fuse_file_info *fi); +int fuse_fs_lock(struct fuse_fs *fs, const char *path, + struct fuse_file_info *fi, int cmd, struct flock *lock); +int fuse_fs_chmod(struct fuse_fs *fs, const char *path, mode_t mode); +int fuse_fs_chown(struct fuse_fs *fs, const char *path, uid_t uid, gid_t gid); +int fuse_fs_truncate(struct fuse_fs *fs, const char *path, off_t size); +int fuse_fs_ftruncate(struct fuse_fs *fs, const char *path, off_t size, + struct fuse_file_info *fi); +int fuse_fs_utimens(struct fuse_fs *fs, const char *path, + const struct timespec tv[2]); +int fuse_fs_access(struct fuse_fs *fs, const char *path, int mask); +int fuse_fs_readlink(struct fuse_fs *fs, const char *path, char *buf, + size_t len); +int fuse_fs_mknod(struct fuse_fs *fs, const char *path, mode_t mode, + dev_t rdev); +int fuse_fs_mkdir(struct fuse_fs *fs, const char *path, mode_t mode); +int fuse_fs_setxattr(struct fuse_fs *fs, const char *path, const char *name, + const char *value, size_t size, int flags); +int fuse_fs_getxattr(struct fuse_fs *fs, const char *path, const char *name, + char *value, size_t size); +int fuse_fs_listxattr(struct fuse_fs *fs, const char *path, char *list, + size_t size); +int fuse_fs_removexattr(struct fuse_fs *fs, const char *path, + const char *name); +int fuse_fs_bmap(struct fuse_fs *fs, const char *path, size_t blocksize, + uint64_t *idx); +void fuse_fs_init(struct fuse_fs *fs, struct fuse_conn_info *conn); +void fuse_fs_destroy(struct fuse_fs *fs); + +/** + * Create a new fuse filesystem object + * + * This is usually called from the factory of a fuse module to create + * a new instance of a filesystem. + * + * @param op the filesystem operations + * @param op_size the size of the fuse_operations structure + * @param user_data user data supplied in the context during the init() method + * @return a new filesystem object + */ +struct fuse_fs *fuse_fs_new(const struct fuse_operations *op, size_t op_size, + void *user_data); + +/* ----------------------------------------------------------- * + * Advanced API for event handling, don't worry about this... * + * ----------------------------------------------------------- */ + +/* NOTE: the following functions are deprecated, and will be removed + from the 3.0 API. Use the lowlevel session functions instead */ + +/** Get session from fuse object */ +struct fuse_session *fuse_get_session(struct fuse *f); + +#ifdef __cplusplus +} +#endif + +#endif /* _FUSE_H_ */ |