mirror of
https://github.com/libfuse/libfuse.git
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df31f2b11e
Add new write_buf() method to the highlevel API. Similarly to the lowlevel write_buf() method, this allows implementing zero copy writes.
685 lines
14 KiB
C
685 lines
14 KiB
C
/*
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fuse subdir module: offset paths with a base directory
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Copyright (C) 2007 Miklos Szeredi <miklos@szeredi.hu>
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This program can be distributed under the terms of the GNU LGPLv2.
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See the file COPYING.LIB
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*/
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#define FUSE_USE_VERSION 26
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#include <fuse.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stddef.h>
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#include <string.h>
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#include <errno.h>
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struct subdir {
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char *base;
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size_t baselen;
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int rellinks;
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struct fuse_fs *next;
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};
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static struct subdir *subdir_get(void)
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{
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return fuse_get_context()->private_data;
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}
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static int subdir_addpath(struct subdir *d, const char *path, char **newpathp)
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{
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char *newpath = NULL;
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if (path != NULL) {
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unsigned newlen = d->baselen + strlen(path);
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newpath = malloc(newlen + 2);
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if (!newpath)
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return -ENOMEM;
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if (path[0] == '/')
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path++;
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strcpy(newpath, d->base);
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strcpy(newpath + d->baselen, path);
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if (!newpath[0])
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strcpy(newpath, ".");
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}
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*newpathp = newpath;
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return 0;
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}
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static int subdir_getattr(const char *path, struct stat *stbuf)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_getattr(d->next, newpath, stbuf);
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free(newpath);
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}
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return err;
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}
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static int subdir_fgetattr(const char *path, struct stat *stbuf,
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struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_fgetattr(d->next, newpath, stbuf, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_access(const char *path, int mask)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_access(d->next, newpath, mask);
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free(newpath);
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}
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return err;
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}
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static int count_components(const char *p)
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{
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int ctr;
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for (; *p == '/'; p++);
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for (ctr = 0; *p; ctr++) {
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for (; *p && *p != '/'; p++);
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for (; *p == '/'; p++);
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}
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return ctr;
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}
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static void strip_common(const char **sp, const char **tp)
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{
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const char *s = *sp;
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const char *t = *tp;
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do {
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for (; *s == '/'; s++);
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for (; *t == '/'; t++);
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*tp = t;
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*sp = s;
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for (; *s == *t && *s && *s != '/'; s++, t++);
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} while ((*s == *t && *s) || (!*s && *t == '/') || (*s == '/' && !*t));
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}
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static void transform_symlink(struct subdir *d, const char *path,
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char *buf, size_t size)
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{
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const char *l = buf;
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size_t llen;
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char *s;
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int dotdots;
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int i;
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if (l[0] != '/' || d->base[0] != '/')
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return;
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strip_common(&l, &path);
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if (l - buf < (long) d->baselen)
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return;
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dotdots = count_components(path);
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if (!dotdots)
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return;
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dotdots--;
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llen = strlen(l);
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if (dotdots * 3 + llen + 2 > size)
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return;
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s = buf + dotdots * 3;
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if (llen)
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memmove(s, l, llen + 1);
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else if (!dotdots)
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strcpy(s, ".");
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else
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*s = '\0';
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for (s = buf, i = 0; i < dotdots; i++, s += 3)
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memcpy(s, "../", 3);
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}
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static int subdir_readlink(const char *path, char *buf, size_t size)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_readlink(d->next, newpath, buf, size);
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if (!err && d->rellinks)
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transform_symlink(d, newpath, buf, size);
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free(newpath);
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}
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return err;
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}
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static int subdir_opendir(const char *path, struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_opendir(d->next, newpath, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_readdir(const char *path, void *buf,
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fuse_fill_dir_t filler, off_t offset,
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struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_readdir(d->next, newpath, buf, filler, offset,
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fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_releasedir(const char *path, struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_releasedir(d->next, newpath, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_mknod(const char *path, mode_t mode, dev_t rdev)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_mknod(d->next, newpath, mode, rdev);
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free(newpath);
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}
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return err;
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}
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static int subdir_mkdir(const char *path, mode_t mode)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_mkdir(d->next, newpath, mode);
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free(newpath);
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}
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return err;
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}
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static int subdir_unlink(const char *path)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_unlink(d->next, newpath);
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free(newpath);
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}
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return err;
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}
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static int subdir_rmdir(const char *path)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_rmdir(d->next, newpath);
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free(newpath);
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}
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return err;
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}
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static int subdir_symlink(const char *from, const char *path)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_symlink(d->next, from, newpath);
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free(newpath);
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}
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return err;
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}
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static int subdir_rename(const char *from, const char *to)
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{
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struct subdir *d = subdir_get();
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char *newfrom;
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char *newto;
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int err = subdir_addpath(d, from, &newfrom);
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if (!err) {
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err = subdir_addpath(d, to, &newto);
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if (!err) {
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err = fuse_fs_rename(d->next, newfrom, newto);
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free(newto);
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}
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free(newfrom);
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}
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return err;
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}
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static int subdir_link(const char *from, const char *to)
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{
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struct subdir *d = subdir_get();
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char *newfrom;
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char *newto;
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int err = subdir_addpath(d, from, &newfrom);
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if (!err) {
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err = subdir_addpath(d, to, &newto);
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if (!err) {
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err = fuse_fs_link(d->next, newfrom, newto);
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free(newto);
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}
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free(newfrom);
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}
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return err;
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}
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static int subdir_chmod(const char *path, mode_t mode)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_chmod(d->next, newpath, mode);
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free(newpath);
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}
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return err;
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}
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static int subdir_chown(const char *path, uid_t uid, gid_t gid)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_chown(d->next, newpath, uid, gid);
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free(newpath);
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}
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return err;
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}
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static int subdir_truncate(const char *path, off_t size)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_truncate(d->next, newpath, size);
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free(newpath);
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}
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return err;
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}
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static int subdir_ftruncate(const char *path, off_t size,
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struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_ftruncate(d->next, newpath, size, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_utimens(const char *path, const struct timespec ts[2])
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_utimens(d->next, newpath, ts);
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free(newpath);
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}
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return err;
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}
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static int subdir_create(const char *path, mode_t mode,
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struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_create(d->next, newpath, mode, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_open(const char *path, struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_open(d->next, newpath, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_read(const char *path, char *buf, size_t size, off_t offset,
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struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_read(d->next, newpath, buf, size, offset, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_write_buf(const char *path, struct fuse_bufvec *buf,
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off_t offset, struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_write_buf(d->next, newpath, buf, offset, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_statfs(const char *path, struct statvfs *stbuf)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_statfs(d->next, newpath, stbuf);
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free(newpath);
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}
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return err;
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}
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static int subdir_flush(const char *path, struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_flush(d->next, newpath, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_release(const char *path, struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_release(d->next, newpath, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_fsync(const char *path, int isdatasync,
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struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_fsync(d->next, newpath, isdatasync, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_fsyncdir(const char *path, int isdatasync,
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struct fuse_file_info *fi)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_fsyncdir(d->next, newpath, isdatasync, fi);
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free(newpath);
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}
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return err;
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}
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static int subdir_setxattr(const char *path, const char *name,
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const char *value, size_t size, int flags)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_setxattr(d->next, newpath, name, value, size,
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flags);
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free(newpath);
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}
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return err;
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}
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static int subdir_getxattr(const char *path, const char *name, char *value,
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size_t size)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_getxattr(d->next, newpath, name, value, size);
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free(newpath);
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}
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return err;
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}
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static int subdir_listxattr(const char *path, char *list, size_t size)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_listxattr(d->next, newpath, list, size);
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free(newpath);
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}
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return err;
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}
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static int subdir_removexattr(const char *path, const char *name)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_removexattr(d->next, newpath, name);
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free(newpath);
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}
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return err;
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}
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static int subdir_lock(const char *path, struct fuse_file_info *fi, int cmd,
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struct flock *lock)
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{
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struct subdir *d = subdir_get();
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char *newpath;
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int err = subdir_addpath(d, path, &newpath);
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if (!err) {
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err = fuse_fs_lock(d->next, newpath, fi, cmd, lock);
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free(newpath);
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}
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return err;
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}
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static int subdir_bmap(const char *path, size_t blocksize, uint64_t *idx)
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{
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struct subdir *d = subdir_get();
|
|
char *newpath;
|
|
int err = subdir_addpath(d, path, &newpath);
|
|
if (!err) {
|
|
err = fuse_fs_bmap(d->next, newpath, blocksize, idx);
|
|
free(newpath);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static void *subdir_init(struct fuse_conn_info *conn)
|
|
{
|
|
struct subdir *d = subdir_get();
|
|
fuse_fs_init(d->next, conn);
|
|
return d;
|
|
}
|
|
|
|
static void subdir_destroy(void *data)
|
|
{
|
|
struct subdir *d = data;
|
|
fuse_fs_destroy(d->next);
|
|
free(d->base);
|
|
free(d);
|
|
}
|
|
|
|
static struct fuse_operations subdir_oper = {
|
|
.destroy = subdir_destroy,
|
|
.init = subdir_init,
|
|
.getattr = subdir_getattr,
|
|
.fgetattr = subdir_fgetattr,
|
|
.access = subdir_access,
|
|
.readlink = subdir_readlink,
|
|
.opendir = subdir_opendir,
|
|
.readdir = subdir_readdir,
|
|
.releasedir = subdir_releasedir,
|
|
.mknod = subdir_mknod,
|
|
.mkdir = subdir_mkdir,
|
|
.symlink = subdir_symlink,
|
|
.unlink = subdir_unlink,
|
|
.rmdir = subdir_rmdir,
|
|
.rename = subdir_rename,
|
|
.link = subdir_link,
|
|
.chmod = subdir_chmod,
|
|
.chown = subdir_chown,
|
|
.truncate = subdir_truncate,
|
|
.ftruncate = subdir_ftruncate,
|
|
.utimens = subdir_utimens,
|
|
.create = subdir_create,
|
|
.open = subdir_open,
|
|
.read = subdir_read,
|
|
.write_buf = subdir_write_buf,
|
|
.statfs = subdir_statfs,
|
|
.flush = subdir_flush,
|
|
.release = subdir_release,
|
|
.fsync = subdir_fsync,
|
|
.fsyncdir = subdir_fsyncdir,
|
|
.setxattr = subdir_setxattr,
|
|
.getxattr = subdir_getxattr,
|
|
.listxattr = subdir_listxattr,
|
|
.removexattr = subdir_removexattr,
|
|
.lock = subdir_lock,
|
|
.bmap = subdir_bmap,
|
|
|
|
.flag_nullpath_ok = 1,
|
|
.flag_nopath = 1,
|
|
};
|
|
|
|
static struct fuse_opt subdir_opts[] = {
|
|
FUSE_OPT_KEY("-h", 0),
|
|
FUSE_OPT_KEY("--help", 0),
|
|
{ "subdir=%s", offsetof(struct subdir, base), 0 },
|
|
{ "rellinks", offsetof(struct subdir, rellinks), 1 },
|
|
{ "norellinks", offsetof(struct subdir, rellinks), 0 },
|
|
FUSE_OPT_END
|
|
};
|
|
|
|
static void subdir_help(void)
|
|
{
|
|
fprintf(stderr,
|
|
" -o subdir=DIR prepend this directory to all paths (mandatory)\n"
|
|
" -o [no]rellinks transform absolute symlinks to relative\n");
|
|
}
|
|
|
|
static int subdir_opt_proc(void *data, const char *arg, int key,
|
|
struct fuse_args *outargs)
|
|
{
|
|
(void) data; (void) arg; (void) outargs;
|
|
|
|
if (!key) {
|
|
subdir_help();
|
|
return -1;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static struct fuse_fs *subdir_new(struct fuse_args *args,
|
|
struct fuse_fs *next[])
|
|
{
|
|
struct fuse_fs *fs;
|
|
struct subdir *d;
|
|
|
|
d = calloc(1, sizeof(struct subdir));
|
|
if (d == NULL) {
|
|
fprintf(stderr, "fuse-subdir: memory allocation failed\n");
|
|
return NULL;
|
|
}
|
|
|
|
if (fuse_opt_parse(args, d, subdir_opts, subdir_opt_proc) == -1)
|
|
goto out_free;
|
|
|
|
if (!next[0] || next[1]) {
|
|
fprintf(stderr, "fuse-subdir: exactly one next filesystem required\n");
|
|
goto out_free;
|
|
}
|
|
|
|
if (!d->base) {
|
|
fprintf(stderr, "fuse-subdir: missing 'subdir' option\n");
|
|
goto out_free;
|
|
}
|
|
|
|
if (d->base[0] && d->base[strlen(d->base)-1] != '/') {
|
|
char *tmp = realloc(d->base, strlen(d->base) + 2);
|
|
if (!tmp) {
|
|
fprintf(stderr, "fuse-subdir: memory allocation failed\n");
|
|
goto out_free;
|
|
}
|
|
d->base = tmp;
|
|
strcat(d->base, "/");
|
|
}
|
|
d->baselen = strlen(d->base);
|
|
d->next = next[0];
|
|
fs = fuse_fs_new(&subdir_oper, sizeof(subdir_oper), d);
|
|
if (!fs)
|
|
goto out_free;
|
|
return fs;
|
|
|
|
out_free:
|
|
free(d->base);
|
|
free(d);
|
|
return NULL;
|
|
}
|
|
|
|
FUSE_REGISTER_MODULE(subdir, subdir_new);
|