diff options
Diffstat (limited to 'example/fuse_lo-plus.c')
| -rw-r--r-- | example/fuse_lo-plus.c | 508 |
1 files changed, 0 insertions, 508 deletions
diff --git a/example/fuse_lo-plus.c b/example/fuse_lo-plus.c deleted file mode 100644 index c27f377..0000000 --- a/example/fuse_lo-plus.c +++ /dev/null @@ -1,508 +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 GPL. - See the file COPYING. -*/ - -/* - * gcc -Wall fuse_lo-plus.c `pkg-config fuse3 --cflags --libs` -o fuse_lo-plus - */ - -#define _GNU_SOURCE -#define FUSE_USE_VERSION 30 - -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif - -#include <fuse_lowlevel.h> -#include <unistd.h> -#include <stdlib.h> -#include <stdio.h> -#include <stddef.h> -#include <stdbool.h> -#include <string.h> -#include <dirent.h> -#include <assert.h> -#include <errno.h> -#include <err.h> - -/* Compat stuff. Doesn't make it work, just makes it compile. */ -#ifndef HAVE_FSTATAT -#warning fstatat(2) needed by this program -int fstatat(int dirfd, const char *pathname, struct stat *buf, int flags) -{ - errno = ENOSYS; - return -1; -} -#endif -#ifndef HAVE_OPENAT -#warning openat(2) needed by this program -int openat(int dirfd, const char *pathname, int flags, ...) -{ - errno = ENOSYS; - return -1; -} -#endif -#ifndef HAVE_READLINKAT -#warning readlinkat(2) needed by this program -ssize_t readlinkat(int dirfd, const char *pathname, char *buf, size_t bufsiz) -{ - errno = ENOSYS; - return -1; -} -#endif -#ifndef AT_EMPTY_PATH -#warning AT_EMPTY_PATH needed by this program -#define AT_EMPTY_PATH 0 -#endif -#ifndef AT_SYMLINK_NOFOLLOW -#warning AT_SYMLINK_NOFOLLOW needed by this program -#define AT_SYMLINK_NOFOLLOW 0 -#endif -#ifndef O_PATH -#warning O_PATH needed by this program -#define O_PATH 0 -#endif -#ifndef O_NOFOLLOW -#warning O_NOFOLLOW needed by this program -#define O_NOFOLLOW 0 -#endif - -struct lo_inode { - struct lo_inode *next; - struct lo_inode *prev; - int fd; - ino_t ino; - dev_t dev; - uint64_t nlookup; -}; - -struct lo_data { - int debug; - struct lo_inode root; -}; - -static struct lo_data *lo_data(fuse_req_t req) -{ - return (struct lo_data *) fuse_req_userdata(req); -} - -static struct lo_inode *lo_inode(fuse_req_t req, fuse_ino_t ino) -{ - if (ino == FUSE_ROOT_ID) - return &lo_data(req)->root; - else - return (struct lo_inode *) (uintptr_t) ino; -} - -static int lo_fd(fuse_req_t req, fuse_ino_t ino) -{ - return lo_inode(req, ino)->fd; -} - -static bool lo_debug(fuse_req_t req) -{ - return lo_data(req)->debug != 0; -} - -static void lo_getattr(fuse_req_t req, fuse_ino_t ino, - struct fuse_file_info *fi) -{ - int res; - struct stat buf; - (void) fi; - - res = fstatat(lo_fd(req, ino), "", &buf, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW); - if (res == -1) - return (void) fuse_reply_err(req, errno); - - fuse_reply_attr(req, &buf, 1.0); -} - -static struct lo_inode *lo_find(struct lo_data *lo, struct stat *st) -{ - struct lo_inode *p; - - for (p = lo->root.next; p != &lo->root; p = p->next) { - if (p->ino == st->st_ino && p->dev == st->st_dev) - return p; - } - return NULL; -} - -static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name, - struct fuse_entry_param *e) -{ - int newfd; - int res; - int saverr; - struct lo_inode *inode; - - memset(e, 0, sizeof(*e)); - e->attr_timeout = 1.0; - e->entry_timeout = 1.0; - - newfd = openat(lo_fd(req, parent), name, O_PATH | O_NOFOLLOW); - if (newfd == -1) - goto out_err; - - res = fstatat(newfd, "", &e->attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW); - if (res == -1) - goto out_err; - - inode = lo_find(lo_data(req), &e->attr); - if (inode) { - close(newfd); - newfd = -1; - } else { - struct lo_inode *prev = &lo_data(req)->root; - struct lo_inode *next = prev->next; - saverr = ENOMEM; - inode = calloc(1, sizeof(struct lo_inode)); - if (!inode) - goto out_err; - - inode->fd = newfd; - inode->ino = e->attr.st_ino; - inode->dev = e->attr.st_dev; - - next->prev = inode; - inode->next = next; - inode->prev = prev; - prev->next = inode; - } - inode->nlookup++; - e->ino = (uintptr_t) inode; - - if (lo_debug(req)) - fprintf(stderr, " %lli/%s -> %lli\n", - (unsigned long long) parent, name, (unsigned long long) e->ino); - - return 0; - -out_err: - saverr = errno; - if (newfd != -1) - close(newfd); - return saverr; -} - -static void lo_lookup(fuse_req_t req, fuse_ino_t parent, const char *name) -{ - struct fuse_entry_param e; - int err; - - err = lo_do_lookup(req, parent, name, &e); - if (err) - fuse_reply_err(req, err); - else - fuse_reply_entry(req, &e); -} - -static void lo_free(struct lo_inode *inode) -{ - struct lo_inode *prev = inode->prev; - struct lo_inode *next = inode->next; - - next->prev = prev; - prev->next = next; - close(inode->fd); - free(inode); -} - -static void lo_forget(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) -{ - struct lo_inode *inode = lo_inode(req, ino); - - if (lo_debug(req)) { - fprintf(stderr, " forget %lli %lli -%lli\n", - (unsigned long long) ino, (unsigned long long) inode->nlookup, - (unsigned long long) nlookup); - } - - assert(inode->nlookup >= nlookup); - inode->nlookup -= nlookup; - - if (!inode->nlookup) - lo_free(inode); - - fuse_reply_none(req); -} - -static void lo_readlink(fuse_req_t req, fuse_ino_t ino) -{ - char buf[PATH_MAX + 1]; - int res; - - res = readlinkat(lo_fd(req, ino), "", buf, sizeof(buf)); - if (res == -1) - return (void) fuse_reply_err(req, errno); - - if (res == sizeof(buf)) - return (void) fuse_reply_err(req, ENAMETOOLONG); - - buf[res] = '\0'; - - fuse_reply_readlink(req, buf); -} - -struct lo_dirp { - int fd; - DIR *dp; - struct dirent *entry; - off_t offset; -}; - -static struct lo_dirp *lo_dirp(struct fuse_file_info *fi) -{ - return (struct lo_dirp *) (uintptr_t) fi->fh; -} - -static void lo_opendir(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) -{ - int error = ENOMEM; - struct lo_dirp *d = calloc(1, sizeof(struct lo_dirp)); - if (d == NULL) - goto out_err; - - d->fd = openat(lo_fd(req, ino), ".", O_RDONLY); - if (d->fd == -1) - goto out_errno; - - d->dp = fdopendir(d->fd); - if (d->dp == NULL) - goto out_errno; - - d->offset = 0; - d->entry = NULL; - - fi->fh = (uintptr_t) d; - fuse_reply_open(req, fi); - return; - -out_errno: - error = errno; -out_err: - if (d) { - if (d->fd != -1) - close(d->fd); - free(d); - } - fuse_reply_err(req, error); -} - -static void lo_do_readdir(fuse_req_t req, fuse_ino_t ino, size_t size, - off_t offset, struct fuse_file_info *fi, int plus) -{ - struct lo_dirp *d = lo_dirp(fi); - char *buf; - char *p; - size_t rem; - int err; - - (void) ino; - - buf = calloc(size, 1); - if (!buf) - return (void) fuse_reply_err(req, ENOMEM); - - if (offset != d->offset) { - seekdir(d->dp, offset); - d->entry = NULL; - d->offset = offset; - } - p = buf; - rem = size; - while (1) { - size_t entsize; - off_t nextoff; - - if (!d->entry) { - errno = 0; - d->entry = readdir(d->dp); - if (!d->entry) { - if (errno && rem == size) { - err = errno; - goto error; - } - break; - } - } - nextoff = telldir(d->dp); - if (plus) { - struct fuse_entry_param e; - - err = lo_do_lookup(req, ino, d->entry->d_name, &e); - if (err) - goto error; - - entsize = fuse_add_direntry_plus(req, p, rem, - d->entry->d_name, - &e, nextoff); - } else { - struct stat st = { - .st_ino = d->entry->d_ino, - .st_mode = d->entry->d_type << 12, - }; - entsize = fuse_add_direntry(req, p, rem, - d->entry->d_name, - &st, nextoff); - } - if (entsize > rem) - break; - - p += entsize; - rem -= entsize; - - d->entry = NULL; - d->offset = nextoff; - } - - fuse_reply_buf(req, buf, size - rem); - free(buf); - return; - -error: - free(buf); - fuse_reply_err(req, err); -} - -static void lo_readdir(fuse_req_t req, fuse_ino_t ino, size_t size, - off_t offset, struct fuse_file_info *fi) -{ - lo_do_readdir(req, ino, size, offset, fi, 0); -} - -static void lo_readdirplus(fuse_req_t req, fuse_ino_t ino, size_t size, - off_t offset, struct fuse_file_info *fi) -{ - lo_do_readdir(req, ino, size, offset, fi, 1); -} - -static void lo_releasedir(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) -{ - struct lo_dirp *d = lo_dirp(fi); - (void) ino; - closedir(d->dp); - free(d); - fuse_reply_err(req, 0); -} - -static void lo_open(fuse_req_t req, fuse_ino_t ino, - struct fuse_file_info *fi) -{ - int fd; - char buf[64]; - - sprintf(buf, "/proc/self/fd/%i", lo_fd(req, ino)); - fd = open(buf, fi->flags & ~O_NOFOLLOW); - if (fd == -1) - return (void) fuse_reply_err(req, errno); - - fi->fh = fd; - fuse_reply_open(req, fi); -} - -static void lo_release(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) -{ - (void) ino; - - close(fi->fh); - fuse_reply_err(req, 0); -} - -static void lo_read(fuse_req_t req, fuse_ino_t ino, size_t size, - off_t offset, struct fuse_file_info *fi) -{ - struct fuse_bufvec buf = FUSE_BUFVEC_INIT(size); - - (void) ino; - - buf.buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK; - buf.buf[0].fd = fi->fh; - buf.buf[0].pos = offset; - - fuse_reply_data(req, &buf, FUSE_BUF_SPLICE_MOVE); -} - -static struct fuse_lowlevel_ops lo_oper = { - .lookup = lo_lookup, - .forget = lo_forget, - .getattr = lo_getattr, - .readlink = lo_readlink, - .opendir = lo_opendir, - .readdir = lo_readdir, - .readdirplus = lo_readdirplus, - .releasedir = lo_releasedir, - .open = lo_open, - .release = lo_release, - .read = lo_read, -}; - -int main(int argc, char *argv[]) -{ - struct fuse_args args = FUSE_ARGS_INIT(argc, argv); - struct fuse_session *se; - struct fuse_cmdline_opts opts; - struct lo_data lo = { .debug = 0 }; - int ret = -1; - - if (fuse_parse_cmdline(&args, &opts) != 0) - return 1; - if (opts.show_help) { - printf("usage: %s [options] <mountpoint>\n\n", argv[0]); - fuse_cmdline_help(); - fuse_lowlevel_help(); - fuse_mount_help(); - ret = 0; - goto err_out1; - } else if (opts.show_version) { - printf("FUSE library version %s\n", fuse_pkgversion()); - fuse_lowlevel_version(); - fuse_mount_version(); - ret = 0; - goto err_out1; - } - - lo.debug = opts.debug; - lo.root.next = lo.root.prev = &lo.root; - lo.root.fd = open("/", O_PATH); - lo.root.nlookup = 2; - if (lo.root.fd == -1) - err(1, "open(\"/\", O_PATH)"); - - se = fuse_session_new(&args, &lo_oper, sizeof(lo_oper), &lo); - if (se == NULL) - goto err_out1; - - if (fuse_set_signal_handlers(se) != 0) - goto err_out2; - - if (fuse_session_mount(se, opts.mountpoint) != 0) - goto err_out3; - - fuse_daemonize(opts.foreground); - - /* Block until ctrl+c or fusermount -u */ - if (opts.singlethread) - ret = fuse_session_loop(se); - else - ret = fuse_session_loop_mt(se); - - fuse_session_unmount(se); -err_out3: - fuse_remove_signal_handlers(se); -err_out2: - fuse_session_destroy(se); -err_out1: - free(opts.mountpoint); - fuse_opt_free_args(&args); - - while (lo.root.next != &lo.root) - lo_free(lo.root.next); - - return ret ? 1 : 0; -} |