fuse.c

FUSE文件系统开发工具,将内核层面的文件系统开发过程平移到应用层面上来。

{
	(void) sig;
	/* Nothing to do */
}

struct fuse_intr_data {
	pthread_t id;
	pthread_cond_t cond;
	int finished;
};

static void fuse_interrupt(fuse_req_t req, void *d_)
{
	struct fuse_intr_data *d = d_;
	struct fuse *f = req_fuse(req);

	if (d->id == pthread_self())
		return;

	pthread_mutex_lock(&f->lock);
	while (!d->finished) {
		struct timeval now;
		struct timespec timeout;

		pthread_kill(d->id, f->conf.intr_signal);
		gettimeofday(&now, NULL);
		timeout.tv_sec = now.tv_sec + 1;
		timeout.tv_nsec = now.tv_usec * 1000;
		pthread_cond_timedwait(&d->cond, &f->lock, &timeout);
	}
	pthread_mutex_unlock(&f->lock);
}

static void fuse_do_finish_interrupt(struct fuse *f, fuse_req_t req,
				     struct fuse_intr_data *d)
{
	pthread_mutex_lock(&f->lock);
	d->finished = 1;
	pthread_cond_broadcast(&d->cond);
	pthread_mutex_unlock(&f->lock);
	fuse_req_interrupt_func(req, NULL, NULL);
	pthread_cond_destroy(&d->cond);
}

static void fuse_do_prepare_interrupt(fuse_req_t req, struct fuse_intr_data *d)
{
	d->id = pthread_self();
	pthread_cond_init(&d->cond, NULL);
	d->finished = 0;
	fuse_req_interrupt_func(req, fuse_interrupt, d);
}

static inline void fuse_finish_interrupt(struct fuse *f, fuse_req_t req,
					 struct fuse_intr_data *d)
{
	if (f->conf.intr)
		fuse_do_finish_interrupt(f, req, d);
}

static inline void fuse_prepare_interrupt(struct fuse *f, fuse_req_t req,
					  struct fuse_intr_data *d)
{
	if (f->conf.intr)
		fuse_do_prepare_interrupt(req, d);
}

#ifndef __FreeBSD__

static int fuse_compat_open(struct fuse_fs *fs, const char *path,
			    struct fuse_file_info *fi)
{
	int err;
	if (!fs->compat || fs->compat >= 25)
		err = fs->op.open(path, fi);
	else if (fs->compat == 22) {
		struct fuse_file_info_compat tmp;
		memcpy(&tmp, fi, sizeof(tmp));
		err = ((struct fuse_operations_compat22 *) &fs->op)->open(path,
									  &tmp);
		memcpy(fi, &tmp, sizeof(tmp));
		fi->fh = tmp.fh;
	} else
		err = ((struct fuse_operations_compat2 *) &fs->op)
			->open(path, fi->flags);
	return err;
}

static int fuse_compat_release(struct fuse_fs *fs, const char *path,
			       struct fuse_file_info *fi)
{
	if (!fs->compat || fs->compat >= 22)
		return fs->op.release(path, fi);
	else
		return ((struct fuse_operations_compat2 *) &fs->op)
			->release(path, fi->flags);
}

static int fuse_compat_opendir(struct fuse_fs *fs, const char *path,
			       struct fuse_file_info *fi)
{
	if (!fs->compat || fs->compat >= 25)
		return fs->op.opendir(path, fi);
	else {
		int err;
		struct fuse_file_info_compat tmp;
		memcpy(&tmp, fi, sizeof(tmp));
		err = ((struct fuse_operations_compat22 *) &fs->op)
			->opendir(path, &tmp);
		memcpy(fi, &tmp, sizeof(tmp));
		fi->fh = tmp.fh;
		return err;
	}
}

static void convert_statfs_compat(struct fuse_statfs_compat1 *compatbuf,
				  struct statvfs *stbuf)
{
	stbuf->f_bsize	 = compatbuf->block_size;
	stbuf->f_blocks	 = compatbuf->blocks;
	stbuf->f_bfree	 = compatbuf->blocks_free;
	stbuf->f_bavail	 = compatbuf->blocks_free;
	stbuf->f_files	 = compatbuf->files;
	stbuf->f_ffree	 = compatbuf->files_free;
	stbuf->f_namemax = compatbuf->namelen;
}

static void convert_statfs_old(struct statfs *oldbuf, struct statvfs *stbuf)
{
	stbuf->f_bsize	 = oldbuf->f_bsize;
	stbuf->f_blocks	 = oldbuf->f_blocks;
	stbuf->f_bfree	 = oldbuf->f_bfree;
	stbuf->f_bavail	 = oldbuf->f_bavail;
	stbuf->f_files	 = oldbuf->f_files;
	stbuf->f_ffree	 = oldbuf->f_ffree;
	stbuf->f_namemax = oldbuf->f_namelen;
}

static int fuse_compat_statfs(struct fuse_fs *fs, const char *path,
			      struct statvfs *buf)
{
	int err;

	if (!fs->compat || fs->compat >= 25) {
		err = fs->op.statfs(fs->compat == 25 ? "/" : path, buf);
	} else if (fs->compat > 11) {
		struct statfs oldbuf;
		err = ((struct fuse_operations_compat22 *) &fs->op)
			->statfs("/", &oldbuf);
		if (!err)
			convert_statfs_old(&oldbuf, buf);
	} else {
		struct fuse_statfs_compat1 compatbuf;
		memset(&compatbuf, 0, sizeof(struct fuse_statfs_compat1));
		err = ((struct fuse_operations_compat1 *) &fs->op)
			->statfs(&compatbuf);
		if (!err)
			convert_statfs_compat(&compatbuf, buf);
	}
	return err;
}

#else /* __FreeBSD__ */

static inline int fuse_compat_open(struct fuse_fs *fs, char *path,
				   struct fuse_file_info *fi)
{
	return fs->op.open(path, fi);
}

static inline int fuse_compat_release(struct fuse_fs *fs, const char *path,
				      struct fuse_file_info *fi)
{
	return fs->op.release(path, fi);
}

static inline int fuse_compat_opendir(struct fuse_fs *fs, const char *path,
				      struct fuse_file_info *fi)
{
	return fs->op.opendir(path, fi);
}

static inline int fuse_compat_statfs(struct fuse_fs *fs, const char *path,
				     struct statvfs *buf)
{
	return fs->op.statfs(fs->compat == 25 ? "/" : path, buf);
}

#endif /* __FreeBSD__ */

int fuse_fs_getattr(struct fuse_fs *fs, const char *path, struct stat *buf)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.getattr)
		return fs->op.getattr(path, buf);
	else
		return -ENOSYS;
}

int fuse_fs_fgetattr(struct fuse_fs *fs, const char *path, struct stat *buf,
		     struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.fgetattr)
		return fs->op.fgetattr(path, buf, fi);
	else if (fs->op.getattr)
		return fs->op.getattr(path, buf);
	else
		return -ENOSYS;
}

int fuse_fs_rename(struct fuse_fs *fs, const char *oldpath,
		   const char *newpath)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.rename)
		return fs->op.rename(oldpath, newpath);
	else
		return -ENOSYS;
}

int fuse_fs_unlink(struct fuse_fs *fs, const char *path)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.unlink)
		return fs->op.unlink(path);
	else
		return -ENOSYS;
}

int fuse_fs_rmdir(struct fuse_fs *fs, const char *path)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.rmdir)
		return fs->op.rmdir(path);
	else
		return -ENOSYS;
}

int fuse_fs_symlink(struct fuse_fs *fs, const char *linkname, const char *path)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.symlink)
		return fs->op.symlink(linkname, path);
	else
		return -ENOSYS;
}

int fuse_fs_link(struct fuse_fs *fs, const char *oldpath, const char *newpath)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.link)
		return fs->op.link(oldpath, newpath);
	else
		return -ENOSYS;
}

int fuse_fs_release(struct fuse_fs *fs,	 const char *path,
		    struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.release)
		return fuse_compat_release(fs, path, fi);
	else
		return 0;
}

int fuse_fs_opendir(struct fuse_fs *fs, const char *path,
		    struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.opendir)
		return fuse_compat_opendir(fs, path, fi);
	else
		return 0;
}

int fuse_fs_open(struct fuse_fs *fs, const char *path,
		 struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.open)
		return fuse_compat_open(fs, path, fi);
	else
		return 0;
}

int fuse_fs_read(struct fuse_fs *fs, const char *path, char *buf, size_t size,
		 off_t off, struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.read)
		return fs->op.read(path, buf, size, off, fi);
	else
		return -ENOSYS;
}

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)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.write)
		return fs->op.write(path, buf, size, off, fi);
	else
		return -ENOSYS;
}

int fuse_fs_fsync(struct fuse_fs *fs, const char *path, int datasync,
		  struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.fsync)
		return fs->op.fsync(path, datasync, fi);
	else
		return -ENOSYS;
}

int fuse_fs_fsyncdir(struct fuse_fs *fs, const char *path, int datasync,
		     struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.fsyncdir)
		return fs->op.fsyncdir(path, datasync, fi);
	else
		return -ENOSYS;
}

int fuse_fs_flush(struct fuse_fs *fs, const char *path,
		  struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.flush)
		return fs->op.flush(path, fi);
	else
		return -ENOSYS;
}

int fuse_fs_statfs(struct fuse_fs *fs, const char *path, struct statvfs *buf)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.statfs)
		return fuse_compat_statfs(fs, path, buf);
	else {
		buf->f_namemax = 255;
		buf->f_bsize = 512;
		return 0;
	}
}

int fuse_fs_releasedir(struct fuse_fs *fs, const char *path,
		       struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.releasedir)
		return fs->op.releasedir(path, fi);
	else
		return 0;
}

static int fill_dir_old(struct fuse_dirhandle *dh, const char *name, int type,
			ino_t ino)
{
	int res;
	struct stat stbuf;

	memset(&stbuf, 0, sizeof(stbuf));
	stbuf.st_mode = type << 12;
	stbuf.st_ino = ino;

	res = dh->filler(dh->buf, name, &stbuf, 0);
	return res ? -ENOMEM : 0;
}

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)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.readdir)
		return fs->op.readdir(path, buf, filler, off, fi);
	else if (fs->op.getdir) {
		struct fuse_dirhandle dh;
		dh.filler = filler;
		dh.buf = buf;
		return fs->op.getdir(path, &dh, fill_dir_old);
	} else
		return -ENOSYS;
}

int fuse_fs_create(struct fuse_fs *fs, const char *path, mode_t mode,
		   struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.create)
		return fs->op.create(path, mode, fi);
	else
		return -ENOSYS;
}

int fuse_fs_lock(struct fuse_fs *fs, const char *path,
		 struct fuse_file_info *fi, int cmd, struct flock *lock)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.lock)
		return fs->op.lock(path, fi, cmd, lock);
	else
		return -ENOSYS;
}

int fuse_fs_chown(struct fuse_fs *fs, const char *path, uid_t uid, gid_t gid)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.chown)
		return fs->op.chown(path, uid, gid);
	else
		return -ENOSYS;
}

int fuse_fs_truncate(struct fuse_fs *fs, const char *path, off_t size)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.truncate)
		return fs->op.truncate(path, size);
	else
		return -ENOSYS;
}

int fuse_fs_ftruncate(struct fuse_fs *fs, const char *path, off_t size,
		      struct fuse_file_info *fi)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.ftruncate)
		return fs->op.ftruncate(path, size, fi);
	else if (fs->op.truncate)
		return fs->op.truncate(path, size);
	else
		return -ENOSYS;
}

int fuse_fs_utimens(struct fuse_fs *fs, const char *path,
		    const struct timespec tv[2])
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.utimens)
		return fs->op.utimens(path, tv);
	else if(fs->op.utime) {
		struct utimbuf buf;
		buf.actime = tv[0].tv_sec;
		buf.modtime = tv[1].tv_sec;
		return fs->op.utime(path, &buf);
	} else
		return -ENOSYS;
}

int fuse_fs_access(struct fuse_fs *fs, const char *path, int mask)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.access)
		return fs->op.access(path, mask);
	else
		return -ENOSYS;
}

int fuse_fs_readlink(struct fuse_fs *fs, const char *path, char *buf,
		     size_t len)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.readlink)
		return fs->op.readlink(path, buf, len);
	else
		return -ENOSYS;
}

int fuse_fs_mknod(struct fuse_fs *fs, const char *path, mode_t mode,
		  dev_t rdev)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.mknod)
		return fs->op.mknod(path, mode, rdev);
	else
		return -ENOSYS;
}

int fuse_fs_mkdir(struct fuse_fs *fs, const char *path, mode_t mode)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.mkdir)
		return fs->op.mkdir(path, mode);
	else
		return -ENOSYS;
}

int fuse_fs_setxattr(struct fuse_fs *fs, const char *path, const char *name,
		     const char *value, size_t size, int flags)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.setxattr)
		return fs->op.setxattr(path, name, value, size, flags);
	else
		return -ENOSYS;
}

int fuse_fs_getxattr(struct fuse_fs *fs, const char *path, const char *name,
		     char *value, size_t size)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.getxattr)
		return fs->op.getxattr(path, name, value, size);
	else
		return -ENOSYS;
}

int fuse_fs_listxattr(struct fuse_fs *fs, const char *path, char *list,
		      size_t size)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.listxattr)
		return fs->op.listxattr(path, list, size);
	else
		return -ENOSYS;
}

int fuse_fs_bmap(struct fuse_fs *fs, const char *path, size_t blocksize,
		 uint64_t *idx)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.bmap)
		return fs->op.bmap(path, blocksize, idx);
	else
		return -ENOSYS;
}

int fuse_fs_removexattr(struct fuse_fs *fs, const char *path, const char *name)
{
	fuse_get_context()->private_data = fs->user_data;
	if (fs->op.removexattr)
		return fs->op.removexattr(path, name);
	else
		return -ENOSYS;
}

static int is_open(struct fuse *f, fuse_ino_t dir, const char *name)
{
	struct node *node;
	int isopen = 0;
	pthread_mutex_lock(&f->lock);
	node = lookup_node(f, dir, name);
	if (node && node->open_count > 0)
		isopen = 1;
	pthread_mutex_unlock(&f->lock);
	return isopen;
}

static char *hidden_name(struct fuse *f, fuse_ino_t dir, const char *oldname,
			 char *newname, size_t bufsize)
{
	struct stat buf;
	struct node *node;
	struct node *newnode;
	char *newpath;
	int res;
	int failctr = 10;