diff options
Diffstat (limited to 'tools/virtiofsd/fuse.h')
| -rw-r--r-- | tools/virtiofsd/fuse.h | 1229 |
1 files changed, 0 insertions, 1229 deletions
diff --git a/tools/virtiofsd/fuse.h b/tools/virtiofsd/fuse.h deleted file mode 100644 index aba13fef2d..0000000000 --- a/tools/virtiofsd/fuse.h +++ /dev/null @@ -1,1229 +0,0 @@ -/* - * 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_ - -/* - * - * This file defines the library interface of FUSE - * - * IMPORTANT: you should define FUSE_USE_VERSION before including this header. - */ - -#include "fuse_common.h" - -#include <fcntl.h> -#include <sys/stat.h> -#include <sys/statvfs.h> -#include <sys/types.h> -#include <sys/uio.h> -#include <time.h> - -/* - * Basic FUSE API - */ - -/** Handle for a FUSE filesystem */ -struct fuse; - -/** - * Readdir flags, passed to ->readdir() - */ -enum fuse_readdir_flags { - /** - * "Plus" mode. - * - * The kernel wants to prefill the inode cache during readdir. The - * filesystem may honour this by filling in the attributes and setting - * FUSE_FILL_DIR_FLAGS for the filler function. The filesystem may also - * just ignore this flag completely. - */ - FUSE_READDIR_PLUS = (1 << 0), -}; - -enum fuse_fill_dir_flags { - /** - * "Plus" mode: all file attributes are valid - * - * The attributes are used by the kernel to prefill the inode cache - * during a readdir. - * - * It is okay to set FUSE_FILL_DIR_PLUS if FUSE_READDIR_PLUS is not set - * and vice versa. - */ - FUSE_FILL_DIR_PLUS = (1 << 1), -}; - -/** - * Function to add an entry in a readdir() operation - * - * The *off* parameter can be any non-zero value that enables the - * filesystem to identify the current point in the directory - * stream. It does not need to be the actual physical position. A - * value of zero is reserved to indicate that seeking in directories - * is not supported. - * - * @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 - * @param flags fill flags - * @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, - enum fuse_fill_dir_flags flags); -/** - * Configuration of the high-level API - * - * This structure is initialized from the arguments passed to - * fuse_new(), and then passed to the file system's init() handler - * which should ensure that the configuration is compatible with the - * file system implementation. - */ -struct fuse_config { - /** - * If `set_gid` is non-zero, the st_gid attribute of each file - * is overwritten with the value of `gid`. - */ - int set_gid; - unsigned int gid; - - /** - * If `set_uid` is non-zero, the st_uid attribute of each file - * is overwritten with the value of `uid`. - */ - int set_uid; - unsigned int uid; - - /** - * If `set_mode` is non-zero, the any permissions bits set in - * `umask` are unset in the st_mode attribute of each file. - */ - int set_mode; - unsigned int umask; - - /** - * The timeout in seconds for which name lookups will be - * cached. - */ - double entry_timeout; - - /** - * The timeout in seconds for which a negative lookup will be - * cached. This means, that if file did not exist (lookup - * retuned ENOENT), the lookup will only be redone after the - * timeout, and the file/directory will be assumed to not - * exist until then. A value of zero means that negative - * lookups are not cached. - */ - double negative_timeout; - - /** - * The timeout in seconds for which file/directory attributes - * (as returned by e.g. the `getattr` handler) are cached. - */ - double attr_timeout; - - /** - * Allow requests to be interrupted - */ - int intr; - - /** - * Specify which signal number to send to the filesystem when - * a request is interrupted. The default is hardcoded to - * USR1. - */ - int intr_signal; - - /** - * Normally, FUSE assigns inodes to paths only for as long as - * the kernel is aware of them. With this option inodes are - * instead remembered for at least this many seconds. This - * will require more memory, but may be necessary when using - * applications that make use of inode numbers. - * - * A number of -1 means that inodes will be remembered for the - * entire life-time of the file-system process. - */ - int remember; - - /** - * The default behavior is that if an open file is deleted, - * the file is renamed to a hidden file (.fuse_hiddenXXX), and - * only removed when the file is finally released. This - * relieves the filesystem implementation of having to deal - * with this problem. This option disables the hiding - * behavior, and files are removed immediately in an unlink - * operation (or in a rename operation which overwrites an - * existing file). - * - * It is recommended that you not use the hard_remove - * option. When hard_remove is set, the following libc - * functions fail on unlinked files (returning errno of - * ENOENT): read(2), write(2), fsync(2), close(2), f*xattr(2), - * ftruncate(2), fstat(2), fchmod(2), fchown(2) - */ - int hard_remove; - - /** - * Honor the st_ino field in the functions getattr() and - * fill_dir(). This value is used to fill in the st_ino field - * in the stat(2), lstat(2), fstat(2) functions and the d_ino - * field in the readdir(2) function. The filesystem does not - * have to guarantee uniqueness, however some applications - * rely on this value being unique for the whole filesystem. - * - * Note that this does *not* affect the inode that libfuse - * and the kernel use internally (also called the "nodeid"). - */ - int use_ino; - - /** - * If use_ino option is not given, still try to fill in the - * d_ino field in readdir(2). If the name was previously - * looked up, and is still in the cache, the inode number - * found there will be used. Otherwise it will be set to -1. - * If use_ino option is given, this option is ignored. - */ - int readdir_ino; - - /** - * This option disables the use of page cache (file content cache) - * in the kernel for this filesystem. This has several affects: - * - * 1. Each read(2) or write(2) system call will initiate one - * or more read or write operations, data will not be - * cached in the kernel. - * - * 2. The return value of the read() and write() system calls - * will correspond to the return values of the read and - * write operations. This is useful for example if the - * file size is not known in advance (before reading it). - * - * Internally, enabling this option causes fuse to set the - * `direct_io` field of `struct fuse_file_info` - overwriting - * any value that was put there by the file system. - */ - int direct_io; - - /** - * This option disables flushing the cache of the file - * contents on every open(2). This should only be enabled on - * filesystems where the file data is never changed - * externally (not through the mounted FUSE filesystem). Thus - * it is not suitable for network filesystems and other - * intermediate filesystems. - * - * NOTE: if this option is not specified (and neither - * direct_io) data is still cached after the open(2), so a - * read(2) system call will not always initiate a read - * operation. - * - * Internally, enabling this option causes fuse to set the - * `keep_cache` field of `struct fuse_file_info` - overwriting - * any value that was put there by the file system. - */ - int kernel_cache; - - /** - * This option is an alternative to `kernel_cache`. Instead of - * unconditionally keeping cached data, the cached data is - * invalidated on open(2) if if the modification time or the - * size of the file has changed since it was last opened. - */ - int auto_cache; - - /** - * The timeout in seconds for which file attributes are cached - * for the purpose of checking if auto_cache should flush the - * file data on open. - */ - int ac_attr_timeout_set; - double ac_attr_timeout; - - /** - * If this option is given the file-system handlers for the - * following operations will not receive path information: - * read, write, flush, release, fsync, readdir, releasedir, - * fsyncdir, lock, ioctl and poll. - * - * For the truncate, getattr, chmod, chown and utimens - * operations the path will be provided only if the struct - * fuse_file_info argument is NULL. - */ - int nullpath_ok; - - /** - * The remaining options are used by libfuse internally and - * should not be touched. - */ - int show_help; - char *modules; - int debug; -}; - - -/** - * 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, truncate, lock, init and - * destroy are special purpose methods, without which a full featured - * filesystem can still be implemented. - * - * In general, all methods are expected to perform any necessary - * permission checking. However, a filesystem may delegate this task - * to the kernel by passing the `default_permissions` mount option to - * `fuse_new()`. In this case, methods will only be called if - * the kernel's permission check has succeeded. - * - * Almost all operations take a path which can be of any length. - */ -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. In that case it is passed to userspace, - * but libfuse and the kernel will still assign a different - * inode for internal use (called the "nodeid"). - * - * `fi` will always be NULL if the file is not currently open, but - * may also be NULL if the file is open. - */ - int (*getattr)(const char *, struct stat *, struct fuse_file_info *fi); - - /** - * 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 - * - * *flags* may be `RENAME_EXCHANGE` or `RENAME_NOREPLACE`. If - * RENAME_NOREPLACE is specified, the filesystem must not - * overwrite *newname* if it exists and return an error - * instead. If `RENAME_EXCHANGE` is specified, the filesystem - * must atomically exchange the two files, i.e. both must - * exist and neither may be deleted. - */ - int (*rename)(const char *, const char *, unsigned int flags); - - /** Create a hard link to a file */ - int (*link)(const char *, const char *); - - /** - * Change the permission bits of a file - * - * `fi` will always be NULL if the file is not currenlty open, but - * may also be NULL if the file is open. - */ - int (*chmod)(const char *, mode_t, struct fuse_file_info *fi); - - /** - * Change the owner and group of a file - * - * `fi` will always be NULL if the file is not currenlty open, but - * may also be NULL if the file is open. - * - * Unless FUSE_CAP_HANDLE_KILLPRIV is disabled, this method is - * expected to reset the setuid and setgid bits. - */ - int (*chown)(const char *, uid_t, gid_t, struct fuse_file_info *fi); - - /** - * Change the size of a file - * - * `fi` will always be NULL if the file is not currenlty open, but - * may also be NULL if the file is open. - * - * Unless FUSE_CAP_HANDLE_KILLPRIV is disabled, this method is - * expected to reset the setuid and setgid bits. - */ - int (*truncate)(const char *, off_t, struct fuse_file_info *fi); - - /** - * Open a file - * - * Open flags are available in fi->flags. The following rules - * apply. - * - * - Creation (O_CREAT, O_EXCL, O_NOCTTY) flags will be - * filtered out / handled by the kernel. - * - * - Access modes (O_RDONLY, O_WRONLY, O_RDWR, O_EXEC, O_SEARCH) - * should be used by the filesystem to check if the operation is - * permitted. If the ``-o default_permissions`` mount option is - * given, this check is already done by the kernel before calling - * open() and may thus be omitted by the filesystem. - * - * - When writeback caching is enabled, the kernel may send - * read requests even for files opened with O_WRONLY. The - * filesystem should be prepared to handle this. - * - * - When writeback caching is disabled, the filesystem is - * expected to properly handle the O_APPEND flag and ensure - * that each write is appending to the end of the file. - * - * - When writeback caching is enabled, the kernel will - * handle O_APPEND. However, unless all changes to the file - * come through the kernel this will not work reliably. The - * filesystem should thus either ignore the O_APPEND flag - * (and let the kernel handle it), or return an error - * (indicating that reliably O_APPEND is not available). - * - * Filesystem may store an arbitrary file handle (pointer, - * index, etc) in fi->fh, and use this in other all other file - * operations (read, write, flush, release, fsync). - * - * Filesystem may also implement stateless file I/O and not store - * anything in fi->fh. - * - * There are also some flags (direct_io, keep_cache) which the - * filesystem may set in fi, to change the way the file is opened. - * See fuse_file_info structure in <fuse_common.h> for more details. - * - * If this request is answered with an error code of ENOSYS - * and FUSE_CAP_NO_OPEN_SUPPORT is set in - * `fuse_conn_info.capable`, this is treated as success and - * future calls to open will also succeed without being send - * to the filesystem process. - * - */ - 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). - * - * Unless FUSE_CAP_HANDLE_KILLPRIV is disabled, this method is - * expected to reset the setuid and setgid bits. - */ - int (*write)(const char *, const char *, size_t, off_t, - struct fuse_file_info *); - - /** - * Get file system statistics - * - * The 'f_favail', 'f_fsid' and 'f_flag' fields are ignored - */ - int (*statfs)(const char *, struct statvfs *); - - /** - * 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, as opposed to - * release which is called on the close of the last file descriptor for - * a file. Under Linux, errors returned by flush() will be passed to - * userspace as errors from close(), so flush() is a good place to write - * back any cached dirty data. However, many applications ignore errors - * on close(), and on non-Linux systems, close() may succeed even if flush() - * returns an error. For these reasons, filesystems should not assume - * that errors returned by flush will ever be noticed or even - * delivered. - * - * NOTE: The flush() method may be called more than once for each - * open(). This happens if more than one file descriptor refers to an - * open file handle, e.g. 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 be called at any - * particular point. It may be called more times than expected, or not - * at all. - * - * [close]: - * http://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html - */ - 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 handle. 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. - */ - 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 *); - - /* - * Open directory - * - * Unless the 'default_permissions' mount option is given, - * this method should check if opendir is permitted for this - * directory. Optionally opendir may also return an arbitrary - * filehandle in the fuse_file_info structure, which will be - * passed to readdir, releasedir and fsyncdir. - */ - 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'. - */ - int (*readdir)(const char *, void *, fuse_fill_dir_t, off_t, - struct fuse_file_info *, enum fuse_readdir_flags); - - /** - * Release directory - */ - 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 - */ - int (*fsyncdir)(const char *, int, struct fuse_file_info *); - - /** - * Initialize filesystem - * - * The return value will passed in the `private_data` field of - * `struct fuse_context` to all file operations, and as a - * parameter to the destroy() method. It overrides the initial - * value provided to fuse_main() / fuse_new(). - */ - void *(*init)(struct fuse_conn_info *conn, struct fuse_config *cfg); - - /** - * Clean up filesystem - * - * Called on filesystem exit. - */ - void (*destroy)(void *private_data); - - /** - * 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 - */ - 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. - */ - int (*create)(const char *, mode_t, 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 unlikely 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. - */ - int (*lock)(const char *, struct fuse_file_info *, int cmd, struct flock *); - - /** - * Change the access and modification times of a file with - * nanosecond resolution - * - * This supersedes the old utime() interface. New applications - * should use this. - * - * `fi` will always be NULL if the file is not currenlty open, but - * may also be NULL if the file is open. - * - * See the utimensat(2) man page for details. - */ - int (*utimens)(const char *, const struct timespec tv[2], - struct fuse_file_info *fi); - - /** - * 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 - */ - int (*bmap)(const char *, size_t blocksize, uint64_t *idx); - - /** - * Ioctl - * - * flags will have FUSE_IOCTL_COMPAT set for 32bit ioctls in - * 64bit environment. The size and direction of data is - * determined by _IOC_*() decoding of cmd. For _IOC_NONE, - * data will be NULL, for _IOC_WRITE data is out area, for - * _IOC_READ in area and if both are set in/out area. In all - * non-NULL cases, the area is of _IOC_SIZE(cmd) bytes. - * - * If flags has FUSE_IOCTL_DIR then the fuse_file_info refers to a - * directory file handle. - * - * Note : the unsigned long request submitted by the application - * is truncated to 32 bits. - */ - int (*ioctl)(const char *, unsigned int cmd, void *arg, - struct fuse_file_info *, unsigned int flags, void *data); - - /** - * Poll for IO readiness events - * - * Note: If ph is non-NULL, the client should notify - * when IO readiness events occur by calling - * fuse_notify_poll() with the specified ph. - * - * Regardless of the number of times poll with a non-NULL ph - * is received, single notification is enough to clear all. - * Notifying more times incurs overhead but doesn't harm - * correctness. - * - * The callee is responsible for destroying ph with - * fuse_pollhandle_destroy() when no longer in use. - */ - int (*poll)(const char *, struct fuse_file_info *, - struct fuse_pollhandle *ph, unsigned *reventsp); - - /* - * Write contents of buffer to an open file - * - * Similar to the write() method, but data is supplied in a - * generic buffer. Use fuse_buf_copy() to transfer data to - * the destination. - * - * Unless FUSE_CAP_HANDLE_KILLPRIV is disabled, this method is - * expected to reset the setuid and setgid bits. - */ - int (*write_buf)(const char *, struct fuse_bufvec *buf, off_t off, - struct fuse_file_info *); - - /* - * Store data from an open file in a buffer - * - * Similar to the read() method, but data is stored and - * returned in a generic buffer. - * - * No actual copying of data has to take place, the source - * file descriptor may simply be stored in the buffer for - * later data transfer. - * - * The buffer must be allocated dynamically and stored at the - * location pointed to by bufp. If the buffer contains memory - * regions, they too must be allocated using malloc(). The - * allocated memory will be freed by the caller. - */ - int (*read_buf)(const char *, struct fuse_bufvec **bufp, size_t size, - off_t off, struct fuse_file_info *); - /** - * Perform BSD file locking operation - * - * The op argument will be either LOCK_SH, LOCK_EX or LOCK_UN - * - * Nonblocking requests will be indicated by ORing LOCK_NB to - * the above operations - * - * For more information see the flock(2) manual page. - * - * Additionally fi->owner will be set to a value unique to - * this open file. This same value will be supplied to - * ->release() when the file is released. - * - * 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. - */ - int (*flock)(const char *, struct fuse_file_info *, int op); - - /** - * Allocates space for an open file - * - * This function ensures that required space is allocated for specified - * file. If this function returns success then any subsequent write - * request to specified range is guaranteed not to fail because of lack - * of space on the file system media. - */ - int (*fallocate)(const char *, int, off_t, off_t, struct fuse_file_info *); - - /** - * Copy a range of data from one file to another - * - * Performs an optimized copy between two file descriptors without the - * additional cost of transferring data through the FUSE kernel module - * to user space (glibc) and then back into the FUSE filesystem again. - * - * In case this method is not implemented, glibc falls back to reading - * data from the source and writing to the destination. Effectively - * doing an inefficient copy of the data. - */ - ssize_t (*copy_file_range)(const char *path_in, - struct fuse_file_info *fi_in, off_t offset_in, - const char *path_out, - struct fuse_file_info *fi_out, off_t offset_out, - size_t size, int flags); - - /** - * Find next data or hole after the specified offset - */ - off_t (*lseek)(const char *, off_t off, int whence, - struct fuse_file_info *); -}; - -/* - * 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; - - /** Process ID of the calling thread */ - pid_t pid; - - /** Private filesystem data */ - void *private_data; - - /** Umask of the calling process */ - mode_t umask; -}; - -/** - * 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, and handles --help and - * --version - * - 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 - * - * Most file systems will have to parse some file-system specific - * arguments before calling this function. It is recommended to do - * this with fuse_opt_parse() and a processing function that passes - * through any unknown options (this can also be achieved by just - * passing NULL as the processing function). That way, the remaining - * options can be passed directly to fuse_main(). - * - * fuse_main() accepts all options that can be passed to - * fuse_parse_cmdline(), fuse_new(), or fuse_session_new(). - * - * Option parsing skips argv[0], which is assumed to contain the - * program name. This element must always be present and is used to - * construct a basic ``usage: `` message for the --help - * output. argv[0] may also be set to the empty string. In this case - * the usage message is suppressed. This can be used by file systems - * to print their own usage line first. See hello.c for an example of - * how to do this. - * - * Note: this is currently implemented as a macro. - * - * The following error codes may be returned from fuse_main(): - * 1: Invalid option arguments - * 2: No mount point specified - * 3: FUSE setup failed - * 4: Mounting failed - * 5: Failed to daemonize (detach from session) - * 6: Failed to set up signal handlers - * 7: An error occured during the life of the file system - * - * @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 - * @param private_data Initial value for the `private_data` - * field of `struct fuse_context`. May be overridden by the - * `struct fuse_operations.init` handler. - * @return 0 on success, nonzero on failure - * - * Example usage, see hello.c - */ -/* - * int fuse_main(int argc, char *argv[], const struct fuse_operations *op, - * void *private_data); - */ -#define fuse_main(argc, argv, op, private_data) \ - fuse_main_real(argc, argv, op, sizeof(*(op)), private_data) - -/* - * More detailed API - */ - -/** - * Print available options (high- and low-level) to stdout. This is - * not an exhaustive list, but includes only those options that may be - * of interest to an end-user of a file system. - * - * The function looks at the argument vector only to determine if - * there are additional modules to be loaded (module=foo option), - * and attempts to call their help functions as well. - * - * @param args the argument vector. - */ -void fuse_lib_help(struct fuse_args *args); - -/** - * Create a new FUSE filesystem. - * - * This function accepts most file-system independent mount options - * (like context, nodev, ro - see mount(8)), as well as the - * FUSE-specific mount options from mount.fuse(8). - * - * If the --help option is specified, the function writes a help text - * to stdout and returns NULL. - * - * Option parsing skips argv[0], which is assumed to contain the - * program name. This element must always be present and is used to - * construct a basic ``usage: `` message for the --help output. If - * argv[0] is set to the empty string, no usage message is included in - * the --help output. - * - * If an unknown option is passed in, an error message is written to - * stderr and the function returns NULL. - * - * @param args argument vector - * @param op the filesystem operations - * @param op_size the size of the fuse_operations structure - * @param private_data Initial value for the `private_data` - * field of `struct fuse_context`. May be overridden by the - * `struct fuse_operations.init` handler. - * @return the created FUSE handle - */ -#if FUSE_USE_VERSION == 30 -struct fuse *fuse_new_30(struct fuse_args *args, - const struct fuse_operations *op, size_t op_size, - void *private_data); -#define fuse_new(args, op, size, data) fuse_new_30(args, op, size, data) -#else -struct fuse *fuse_new(struct fuse_args *args, const struct fuse_operations *op, - size_t op_size, void *private_data); -#endif - -/** - * Mount a FUSE file system. - * - * @param mountpoint the mount point path - * @param f the FUSE handle - * - * @return 0 on success, -1 on failure. - **/ -int fuse_mount(struct fuse *f, const char *mountpoint); - -/** - * Unmount a FUSE file system. - * - * See fuse_session_unmount() for additional information. - * - * @param f the FUSE handle - **/ -void fuse_unmount(struct fuse *f); - -/** - * Destroy the FUSE handle. - * - * 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. - * - * For a description of the return value and the conditions when the - * event loop exits, refer to the documentation of - * fuse_session_loop(). - * - * @param f the FUSE handle - * @return see fuse_session_loop() - * - * See also: fuse_loop_mt() - */ -int fuse_loop(struct fuse *f); - -/** - * Flag session as terminated - * - * This function will cause any running event loops to exit on - * the next opportunity. - * - * @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 the current request has already been interrupted - * - * @return 1 if the request has been interrupted, 0 otherwise - */ -int fuse_interrupted(void); - -/** - * Invalidates cache for the given path. - * - * This calls fuse_lowlevel_notify_inval_inode internally. - * - * @return 0 on successful invalidation, negative error value otherwise. - * This routine may return -ENOENT to indicate that there was - * no entry to be invalidated, e.g., because the path has not - * been seen before or has been forgotten; this should not be - * considered to be an error. - */ -int fuse_invalidate_path(struct fuse *f, const char *path); - -/** - * 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, void *private_data); - -/** - * Start the cleanup thread when using option "remember". - * - * This is done automatically by fuse_loop_mt() - * @param fuse struct fuse pointer for fuse instance - * @return 0 on success and -1 on error - */ -int fuse_start_cleanup_thread(struct fuse *fuse); - -/** - * Stop the cleanup thread when using option "remember". - * - * This is done automatically by fuse_loop_mt() - * @param fuse struct fuse pointer for fuse instance - */ -void fuse_stop_cleanup_thread(struct fuse *fuse); - -/** - * Iterate over cache removing stale entries - * use in conjunction with "-oremember" - * - * NOTE: This is already done for the standard sessions - * - * @param fuse struct fuse pointer for fuse instance - * @return the number of seconds until the next cleanup - */ -int fuse_clean_cache(struct fuse *fuse); - -/* - * 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, - struct fuse_file_info *fi); -int fuse_fs_rename(struct fuse_fs *fs, const char *oldpath, const char *newpath, - unsigned int flags); -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_read_buf(struct fuse_fs *fs, const char *path, - struct fuse_bufvec **bufp, 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_write_buf(struct fuse_fs *fs, const char *path, - struct fuse_bufvec *buf, 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); -int fuse_fs_statfs(struct fuse_fs *fs, const char *path, struct statvfs *buf); -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, enum fuse_readdir_flags flags); -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_flock(struct fuse_fs *fs, const char *path, - struct fuse_file_info *fi, int op); -int fuse_fs_chmod(struct fuse_fs *fs, const char *path, mode_t mode, - struct fuse_file_info *fi); -int fuse_fs_chown(struct fuse_fs *fs, const char *path, uid_t uid, gid_t gid, - struct fuse_file_info *fi); -int fuse_fs_truncate(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], struct fuse_file_info *fi); -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); -int fuse_fs_ioctl(struct fuse_fs *fs, const char *path, unsigned int cmd, - void *arg, struct fuse_file_info *fi, unsigned int flags, - void *data); -int fuse_fs_poll(struct fuse_fs *fs, const char *path, - struct fuse_file_info *fi, struct fuse_pollhandle *ph, - unsigned *reventsp); -int fuse_fs_fallocate(struct fuse_fs *fs, const char *path, int mode, - off_t offset, off_t length, struct fuse_file_info *fi); -ssize_t fuse_fs_copy_file_range(struct fuse_fs *fs, const char *path_in, - struct fuse_file_info *fi_in, off_t off_in, - const char *path_out, - struct fuse_file_info *fi_out, off_t off_out, - size_t len, int flags); -off_t fuse_fs_lseek(struct fuse_fs *fs, const char *path, off_t off, int whence, - struct fuse_file_info *fi); -void fuse_fs_init(struct fuse_fs *fs, struct fuse_conn_info *conn, - struct fuse_config *cfg); -void fuse_fs_destroy(struct fuse_fs *fs); - -int fuse_notify_poll(struct fuse_pollhandle *ph); - -/** - * 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 private_data Initial value for the `private_data` - * field of `struct fuse_context`. May be overridden by the - * `struct fuse_operations.init` handler. - * @return a new filesystem object - */ -struct fuse_fs *fuse_fs_new(const struct fuse_operations *op, size_t op_size, - void *private_data); - -/** - * Factory for creating filesystem objects - * - * The function may use and remove options from 'args' that belong - * to this module. - * - * For now the 'fs' vector always contains exactly one filesystem. - * This is the filesystem which will be below the newly created - * filesystem in the stack. - * - * @param args the command line arguments - * @param fs NULL terminated filesystem object vector - * @return the new filesystem object - */ -typedef struct fuse_fs *(*fuse_module_factory_t)(struct fuse_args *args, - struct fuse_fs *fs[]); -/** - * Register filesystem module - * - * If the "-omodules=*name*_:..." option is present, filesystem - * objects are created and pushed onto the stack with the *factory_* - * function. - * - * @param name_ the name of this filesystem module - * @param factory_ the factory function for this filesystem module - */ -#define FUSE_REGISTER_MODULE(name_, factory_) \ - fuse_module_factory_t fuse_module_##name_##_factory = factory_ - -/** Get session from fuse object */ -struct fuse_session *fuse_get_session(struct fuse *f); - -/** - * Open a FUSE file descriptor and set up the mount for the given - * mountpoint and flags. - * - * @param mountpoint reference to the mount in the file system - * @param options mount options - * @return the FUSE file descriptor or -1 upon error - */ -int fuse_open_channel(const char *mountpoint, const char *options); - -#endif /* FUSE_H_ */ |