minix/lib/libpuffs/null.c

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/* $NetBSD: null.c,v 1.33 2011/11/25 15:02:02 manu Exp $ */
/*
* Copyright (c) 2007 Antti Kantee. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if !defined(lint)
__RCSID("$NetBSD: null.c,v 1.33 2011/11/25 15:02:02 manu Exp $");
#endif /* !lint */
/*
* A "nullfs" using puffs, i.e. maps one location in the hierarchy
* to another using standard system calls.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <puffs.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
PUFFSOP_PROTOS(puffs_null)
/*
* set attributes to what is specified. XXX: no rollback in case of failure
*/
static int
processvattr(const char *path, const struct vattr *va, int regular)
{
struct timeval tv[2];
/* XXX: -1 == PUFFS_VNOVAL, but shouldn't trust that */
if (va->va_uid != (unsigned)-1 || va->va_gid != (unsigned)-1)
if (lchown(path, va->va_uid, va->va_gid) == -1)
return errno;
if (va->va_mode != (unsigned)PUFFS_VNOVAL)
if (lchmod(path, va->va_mode) == -1)
return errno;
/* sloppy */
if (va->va_atime.tv_sec != (time_t)PUFFS_VNOVAL
|| va->va_mtime.tv_sec != (time_t)PUFFS_VNOVAL) {
TIMESPEC_TO_TIMEVAL(&tv[0], &va->va_atime);
TIMESPEC_TO_TIMEVAL(&tv[1], &va->va_mtime);
if (lutimes(path, tv) == -1)
return errno;
}
if (regular && va->va_size != (u_quad_t)PUFFS_VNOVAL)
if (truncate(path, (off_t)va->va_size) == -1)
return errno;
return 0;
}
/*
* Kludge to open files which aren't writable *any longer*. This kinda
* works because the vfs layer does validation checks based on the file's
* permissions to allow writable opening before opening them. However,
* the problem arises if we want to create a file, write to it (cache),
* adjust permissions and then flush the file.
*/
static int
writeableopen(const char *path)
{
struct stat sb;
mode_t origmode;
int sverr = 0;
int fd;
fd = open(path, O_WRONLY);
if (fd == -1) {
if (errno == EACCES) {
if (stat(path, &sb) == -1)
return -1;
origmode = sb.st_mode & ALLPERMS;
if (chmod(path, 0200) == -1)
return -1;
fd = open(path, O_WRONLY);
if (fd == -1)
sverr = errno;
chmod(path, origmode);
if (sverr)
errno = sverr;
} else
return -1;
}
return fd;
}
/*ARGSUSED*/
static void *
inodecmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg)
{
ino_t *cmpino = arg;
if (pn->pn_va.va_fileid == *cmpino)
return pn;
return NULL;
}
static int
makenode(struct puffs_usermount *pu, struct puffs_newinfo *pni,
const struct puffs_cn *pcn, const struct vattr *va, int regular)
{
struct puffs_node *pn;
struct stat sb;
int rv;
if ((rv = processvattr(PCNPATH(pcn), va, regular)) != 0)
return rv;
pn = puffs_pn_new(pu, NULL);
if (!pn)
return ENOMEM;
puffs_setvattr(&pn->pn_va, va);
if (lstat(PCNPATH(pcn), &sb) == -1)
return errno;
puffs_stat2vattr(&pn->pn_va, &sb);
puffs_newinfo_setcookie(pni, pn);
return 0;
}
/* This should be called first and overriden from the file system */
void
puffs_null_setops(struct puffs_ops *pops)
{
PUFFSOP_SET(pops, puffs_null, fs, statvfs);
PUFFSOP_SETFSNOP(pops, unmount);
PUFFSOP_SETFSNOP(pops, sync);
PUFFSOP_SET(pops, puffs_null, fs, fhtonode);
PUFFSOP_SET(pops, puffs_null, fs, nodetofh);
PUFFSOP_SET(pops, puffs_null, node, lookup);
PUFFSOP_SET(pops, puffs_null, node, create);
PUFFSOP_SET(pops, puffs_null, node, mknod);
PUFFSOP_SET(pops, puffs_null, node, getattr);
PUFFSOP_SET(pops, puffs_null, node, setattr);
PUFFSOP_SET(pops, puffs_null, node, fsync);
PUFFSOP_SET(pops, puffs_null, node, remove);
PUFFSOP_SET(pops, puffs_null, node, link);
PUFFSOP_SET(pops, puffs_null, node, rename);
PUFFSOP_SET(pops, puffs_null, node, mkdir);
PUFFSOP_SET(pops, puffs_null, node, rmdir);
PUFFSOP_SET(pops, puffs_null, node, symlink);
PUFFSOP_SET(pops, puffs_null, node, readlink);
PUFFSOP_SET(pops, puffs_null, node, readdir);
PUFFSOP_SET(pops, puffs_null, node, read);
PUFFSOP_SET(pops, puffs_null, node, write);
PUFFSOP_SET(pops, puffs_genfs, node, reclaim);
}
/*ARGSUSED*/
int
puffs_null_fs_statvfs(struct puffs_usermount *pu, struct statvfs *svfsb)
{
if (statvfs(PNPATH(puffs_getroot(pu)), svfsb) == -1)
return errno;
return 0;
}
/*
* XXX: this is the stupidest crap ever, but:
* getfh() returns the fhandle type, when we are expected to deliver
* the fid type. Just adjust it a bit and stop whining.
*
* Yes, this really really needs fixing. Yes, *REALLY*.
*/
#define FHANDLE_HEADERLEN 8
struct kernfid {
unsigned short fid_len; /* length of data in bytes */
unsigned short fid_reserved; /* compat: historic align */
char fid_data[0]; /* data (variable length) */
};
/*ARGSUSED*/
static void *
fhcmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg)
{
struct kernfid *kf1, *kf2;
if ((kf1 = pn->pn_data) == NULL)
return NULL;
kf2 = arg;
if (kf1->fid_len != kf2->fid_len)
return NULL;
/*LINTED*/
if (memcmp(kf1, kf2, kf1->fid_len) == 0)
return pn;
return NULL;
}
/*
* This routine only supports file handles which have been issued while
* the server was alive. Not really stable ones, that is.
*/
/*ARGSUSED*/
int
puffs_null_fs_fhtonode(struct puffs_usermount *pu, void *fid, size_t fidsize,
struct puffs_newinfo *pni)
{
struct puffs_node *pn_res;
pn_res = puffs_pn_nodewalk(pu, fhcmp, fid);
if (pn_res == NULL)
return ENOENT;
puffs_newinfo_setcookie(pni, pn_res);
puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type);
puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size);
puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev);
return 0;
}
/*ARGSUSED*/
int
puffs_null_fs_nodetofh(struct puffs_usermount *pu, puffs_cookie_t opc,
void *fid, size_t *fidsize)
{
struct puffs_node *pn = opc;
struct kernfid *kfid;
void *bounce;
int rv;
rv = 0;
bounce = NULL;
if (*fidsize) {
bounce = malloc(*fidsize + FHANDLE_HEADERLEN);
if (!bounce)
return ENOMEM;
*fidsize += FHANDLE_HEADERLEN;
}
if (getfh(PNPATH(pn), bounce, fidsize) == -1)
rv = errno;
else
memcpy(fid, (uint8_t *)bounce + FHANDLE_HEADERLEN,
*fidsize - FHANDLE_HEADERLEN);
kfid = fid;
if (rv == 0) {
*fidsize = kfid->fid_len;
pn->pn_data = malloc(*fidsize);
if (pn->pn_data == NULL)
abort(); /* lazy */
memcpy(pn->pn_data, fid, *fidsize);
} else {
*fidsize -= FHANDLE_HEADERLEN;
}
free(bounce);
return rv;
}
int
puffs_null_node_lookup(struct puffs_usermount *pu, puffs_cookie_t opc,
struct puffs_newinfo *pni, const struct puffs_cn *pcn)
{
struct puffs_node *pn = opc, *pn_res;
struct stat sb;
int rv;
assert(pn->pn_va.va_type == VDIR);
/*
* Note to whoever is copypasting this: you must first check
* if the node is there and only then do nodewalk. Alternatively
* you could make sure that you don't return unlinked/rmdir'd
* nodes in some other fashion
*/
rv = lstat(PCNPATH(pcn), &sb);
if (rv)
return errno;
/* XXX2: nodewalk is a bit too slow here */
pn_res = puffs_pn_nodewalk(pu, inodecmp, &sb.st_ino);
if (pn_res == NULL) {
pn_res = puffs_pn_new(pu, NULL);
if (pn_res == NULL)
return ENOMEM;
puffs_stat2vattr(&pn_res->pn_va, &sb);
}
puffs_newinfo_setcookie(pni, pn_res);
puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type);
puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size);
puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev);
return 0;
}
/*ARGSUSED*/
int
puffs_null_node_create(struct puffs_usermount *pu, puffs_cookie_t opc,
struct puffs_newinfo *pni, const struct puffs_cn *pcn,
const struct vattr *va)
{
int fd, rv;
fd = open(PCNPATH(pcn), O_RDWR | O_CREAT | O_TRUNC);
if (fd == -1)
return errno;
close(fd);
rv = makenode(pu, pni, pcn, va, 1);
if (rv)
unlink(PCNPATH(pcn));
return rv;
}
/*ARGSUSED*/
int
puffs_null_node_mknod(struct puffs_usermount *pu, puffs_cookie_t opc,
struct puffs_newinfo *pni, const struct puffs_cn *pcn,
const struct vattr *va)
{
mode_t mode;
int rv;
mode = puffs_addvtype2mode(va->va_mode, va->va_type);
if (mknod(PCNPATH(pcn), mode, va->va_rdev) == -1)
return errno;
rv = makenode(pu, pni, pcn, va, 0);
if (rv)
unlink(PCNPATH(pcn));
return rv;
}
/*ARGSUSED*/
int
puffs_null_node_getattr(struct puffs_usermount *pu, puffs_cookie_t opc,
struct vattr *va, const struct puffs_cred *pcred)
{
struct puffs_node *pn = opc;
struct stat sb;
if (lstat(PNPATH(pn), &sb) == -1)
return errno;
puffs_stat2vattr(va, &sb);
return 0;
}
/*ARGSUSED*/
int
puffs_null_node_setattr(struct puffs_usermount *pu, puffs_cookie_t opc,
const struct vattr *va, const struct puffs_cred *pcred)
{
struct puffs_node *pn = opc;
int rv;
rv = processvattr(PNPATH(pn), va, pn->pn_va.va_type == VREG);
if (rv)
return rv;
puffs_setvattr(&pn->pn_va, va);
return 0;
}
/*ARGSUSED*/
int
puffs_null_node_fsync(struct puffs_usermount *pu, puffs_cookie_t opc,
const struct puffs_cred *pcred, int how,
off_t offlo, off_t offhi)
{
struct puffs_node *pn = opc;
int fd, rv;
int fflags;
struct stat sb;
rv = 0;
if (stat(PNPATH(pn), &sb) == -1)
return errno;
if (S_ISDIR(sb.st_mode)) {
DIR *dirp;
if ((dirp = opendir(PNPATH(pn))) == 0)
return errno;
fd = dirfd(dirp);
if (fd == -1)
return errno;
if (fsync(fd) == -1)
rv = errno;
} else {
fd = writeableopen(PNPATH(pn));
if (fd == -1)
return errno;
if (how & PUFFS_FSYNC_DATAONLY)
fflags = FDATASYNC;
else
fflags = FFILESYNC;
if (how & PUFFS_FSYNC_CACHE)
fflags |= FDISKSYNC;
if (fsync_range(fd, fflags, offlo, offhi - offlo) == -1)
rv = errno;
}
close(fd);
return rv;
}
/*ARGSUSED*/
int
puffs_null_node_remove(struct puffs_usermount *pu, puffs_cookie_t opc,
puffs_cookie_t targ, const struct puffs_cn *pcn)
{
struct puffs_node *pn_targ = targ;
if (unlink(PNPATH(pn_targ)) == -1)
return errno;
puffs_pn_remove(pn_targ);
return 0;
}
/*ARGSUSED*/
int
puffs_null_node_link(struct puffs_usermount *pu, puffs_cookie_t opc,
puffs_cookie_t targ, const struct puffs_cn *pcn)
{
struct puffs_node *pn_targ = targ;
if (link(PNPATH(pn_targ), PCNPATH(pcn)) == -1)
return errno;
return 0;
}
/*ARGSUSED*/
int
puffs_null_node_rename(struct puffs_usermount *pu, puffs_cookie_t opc,
puffs_cookie_t src, const struct puffs_cn *pcn_src,
puffs_cookie_t targ_dir, puffs_cookie_t targ,
const struct puffs_cn *pcn_targ)
{
struct puffs_node *pn_targ = targ;
if (rename(PCNPATH(pcn_src), PCNPATH(pcn_targ)) == -1)
return errno;
if (pn_targ)
puffs_pn_remove(pn_targ);
return 0;
}
/*ARGSUSED*/
int
puffs_null_node_mkdir(struct puffs_usermount *pu, puffs_cookie_t opc,
struct puffs_newinfo *pni, const struct puffs_cn *pcn,
const struct vattr *va)
{
int rv;
if (mkdir(PCNPATH(pcn), va->va_mode) == -1)
return errno;
rv = makenode(pu, pni, pcn, va, 0);
if (rv)
rmdir(PCNPATH(pcn));
return rv;
}
/*ARGSUSED*/
int
puffs_null_node_rmdir(struct puffs_usermount *pu, puffs_cookie_t opc,
puffs_cookie_t targ, const struct puffs_cn *pcn)
{
struct puffs_node *pn_targ = targ;
if (rmdir(PNPATH(pn_targ)) == -1)
return errno;
puffs_pn_remove(pn_targ);
return 0;
}
/*ARGSUSED*/
int
puffs_null_node_symlink(struct puffs_usermount *pu, puffs_cookie_t opc,
struct puffs_newinfo *pni, const struct puffs_cn *pcn,
const struct vattr *va, const char *linkname)
{
int rv;
if (symlink(linkname, PCNPATH(pcn)) == -1)
return errno;
rv = makenode(pu, pni, pcn, va, 0);
if (rv)
unlink(PCNPATH(pcn));
return rv;
}
/*ARGSUSED*/
int
puffs_null_node_readlink(struct puffs_usermount *pu, puffs_cookie_t opc,
const struct puffs_cred *pcred, char *linkname, size_t *linklen)
{
struct puffs_node *pn = opc;
ssize_t rv;
rv = readlink(PNPATH(pn), linkname, *linklen);
if (rv == -1)
return errno;
*linklen = rv;
return 0;
}
/*ARGSUSED*/
int
puffs_null_node_readdir(struct puffs_usermount *pu, puffs_cookie_t opc,
struct dirent *de, off_t *off, size_t *reslen,
const struct puffs_cred *pcred, int *eofflag, off_t *cookies,
size_t *ncookies)
{
struct puffs_node *pn = opc;
struct dirent entry, *result;
DIR *dp;
off_t i;
int rv;
*ncookies = 0;
dp = opendir(PNPATH(pn));
if (dp == NULL)
return errno;
rv = 0;
i = *off;
/*
* XXX: need to do trickery here, telldir/seekdir would be nice, but
* then we'd need to keep state, which I'm too lazy to keep
*/
while (i--) {
rv = readdir_r(dp, &entry, &result);
if (rv != 0)
goto out;
if (!result) {
*eofflag = 1;
goto out;
}
}
for (;;) {
rv = readdir_r(dp, &entry, &result);
if (rv != 0)
goto out;
if (!result) {
*eofflag = 1;
goto out;
}
if (_DIRENT_SIZE(result) > *reslen)
goto out;
*de = *result;
*reslen -= _DIRENT_SIZE(result);
de = _DIRENT_NEXT(de);
(*off)++;
PUFFS_STORE_DCOOKIE(cookies, ncookies, *off);
}
out:
closedir(dp);
return 0;
}
/*ARGSUSED*/
int
puffs_null_node_read(struct puffs_usermount *pu, puffs_cookie_t opc,
uint8_t *buf, off_t offset, size_t *buflen,
const struct puffs_cred *pcred, int ioflag)
{
struct puffs_node *pn = opc;
ssize_t n;
off_t off;
int fd, rv;
rv = 0;
fd = open(PNPATH(pn), O_RDONLY);
if (fd == -1)
return errno;
off = lseek(fd, offset, SEEK_SET);
if (off == -1) {
rv = errno;
goto out;
}
n = read(fd, buf, *buflen);
if (n == -1)
rv = errno;
else
*buflen -= n;
out:
close(fd);
return rv;
}
/*ARGSUSED*/
int
puffs_null_node_write(struct puffs_usermount *pu, puffs_cookie_t opc,
uint8_t *buf, off_t offset, size_t *buflen,
const struct puffs_cred *pcred, int ioflag)
{
struct puffs_node *pn = opc;
ssize_t n;
off_t off;
int fd, rv;
rv = 0;
fd = writeableopen(PNPATH(pn));
if (fd == -1)
return errno;
off = lseek(fd, offset, SEEK_SET);
if (off == -1) {
rv = errno;
goto out;
}
n = write(fd, buf, *buflen);
if (n == -1)
rv = errno;
else
*buflen -= n;
out:
close(fd);
return rv;
}