freebsd-dev/sys/fs/pseudofs/pseudofs.c
Jeff Roberson d9b2d9f7a2 - Update vfs_root implementations to match the new prototype. None of
these filesystems will support shared locks until they are explicitly
   modified to do so.  Careful review must be done to ensure that this
   is safe for each individual filesystem.

Sponsored by:	Isilon Systems, Inc.
2005-03-24 07:36:16 +00:00

413 lines
9.2 KiB
C

/*-
* Copyright (c) 2001 Dag-Erling Coïdan Smørgrav
* 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
* in this position and unchanged.
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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 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>
__FBSDID("$FreeBSD$");
#include "opt_pseudofs.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <fs/pseudofs/pseudofs.h>
#include <fs/pseudofs/pseudofs_internal.h>
static MALLOC_DEFINE(M_PFSNODES, "pfs_nodes", "pseudofs nodes");
SYSCTL_NODE(_vfs, OID_AUTO, pfs, CTLFLAG_RW, 0,
"pseudofs");
#if PFS_FSNAMELEN != MFSNAMELEN
#error "PFS_FSNAMELEN is not equal to MFSNAMELEN"
#endif
/*
* Add a node to a directory
*/
static int
_pfs_add_node(struct pfs_node *parent, struct pfs_node *node)
{
KASSERT(parent != NULL,
("%s(): parent is NULL", __func__));
KASSERT(parent->pn_info != NULL,
("%s(): parent has no pn_info", __func__));
KASSERT(parent->pn_type == pfstype_dir ||
parent->pn_type == pfstype_procdir ||
parent->pn_type == pfstype_root,
("%s(): parent is not a directory", __func__));
/* XXX should check for duplicate names etc. */
mtx_lock(&parent->pn_info->pi_mutex);
node->pn_info = parent->pn_info;
node->pn_parent = parent;
node->pn_next = parent->pn_nodes;
parent->pn_nodes = node;
/* Propagate flag to all child nodes (and thus their vnodes) */
if ((parent->pn_flags & PFS_PROCDEP) != 0)
node->pn_flags |= PFS_PROCDEP;
mtx_unlock(&parent->pn_info->pi_mutex);
return (0);
}
/*
* Add . and .. to a directory
*/
static int
_pfs_fixup_dir(struct pfs_node *parent)
{
struct pfs_node *dir;
MALLOC(dir, struct pfs_node *, sizeof *dir,
M_PFSNODES, M_WAITOK|M_ZERO);
dir->pn_name[0] = '.';
dir->pn_type = pfstype_this;
if (_pfs_add_node(parent, dir) != 0) {
FREE(dir, M_PFSNODES);
return (-1);
}
MALLOC(dir, struct pfs_node *, sizeof *dir,
M_PFSNODES, M_WAITOK|M_ZERO);
dir->pn_name[0] = dir->pn_name[1] = '.';
dir->pn_type = pfstype_parent;
if (_pfs_add_node(parent, dir) != 0) {
FREE(dir, M_PFSNODES);
return (-1);
}
return (0);
}
/*
* Create a directory
*/
struct pfs_node *
pfs_create_dir(struct pfs_node *parent, const char *name,
pfs_attr_t attr, pfs_vis_t vis, int flags)
{
struct pfs_node *dir;
KASSERT(strlen(name) < PFS_NAMELEN,
("%s(): node name is too long", __func__));
MALLOC(dir, struct pfs_node *, sizeof *dir,
M_PFSNODES, M_WAITOK|M_ZERO);
strcpy(dir->pn_name, name);
dir->pn_type = (flags & PFS_PROCDEP) ? pfstype_procdir : pfstype_dir;
dir->pn_attr = attr;
dir->pn_vis = vis;
dir->pn_flags = flags;
if (_pfs_add_node(parent, dir) != 0) {
FREE(dir, M_PFSNODES);
return (NULL);
}
if (_pfs_fixup_dir(dir) != 0) {
pfs_destroy(dir);
return (NULL);
}
return (dir);
}
/*
* Create a file
*/
struct pfs_node *
pfs_create_file(struct pfs_node *parent, const char *name, pfs_fill_t fill,
pfs_attr_t attr, pfs_vis_t vis, int flags)
{
struct pfs_node *node;
KASSERT(strlen(name) < PFS_NAMELEN,
("%s(): node name is too long", __func__));
MALLOC(node, struct pfs_node *, sizeof *node,
M_PFSNODES, M_WAITOK|M_ZERO);
strcpy(node->pn_name, name);
node->pn_type = pfstype_file;
node->pn_func = fill;
node->pn_attr = attr;
node->pn_vis = vis;
node->pn_flags = flags;
if (_pfs_add_node(parent, node) != 0) {
FREE(node, M_PFSNODES);
return (NULL);
}
return (node);
}
/*
* Create a symlink
*/
struct pfs_node *
pfs_create_link(struct pfs_node *parent, const char *name, pfs_fill_t fill,
pfs_attr_t attr, pfs_vis_t vis, int flags)
{
struct pfs_node *node;
node = pfs_create_file(parent, name, fill, attr, vis, flags);
if (node == NULL)
return (NULL);
node->pn_type = pfstype_symlink;
return (node);
}
/*
* Locate a node by name
*/
struct pfs_node *
pfs_find_node(struct pfs_node *parent, const char *name)
{
struct pfs_node *node;
for (node = parent->pn_nodes; node != NULL; node = node->pn_next)
if (strcmp(node->pn_name, name) == 0)
return (node);
return (NULL);
}
/*
* Destroy a node or a tree of nodes
*/
int
pfs_destroy(struct pfs_node *node)
{
struct pfs_node *parent, *rover;
KASSERT(node != NULL,
("%s(): node is NULL", __func__));
KASSERT(node->pn_info != NULL,
("%s(): node has no pn_info", __func__));
/* destroy children */
if (node->pn_type == pfstype_dir ||
node->pn_type == pfstype_procdir ||
node->pn_type == pfstype_root)
while (node->pn_nodes != NULL)
pfs_destroy(node->pn_nodes);
/* unlink from parent */
if ((parent = node->pn_parent) != NULL) {
KASSERT(parent->pn_info == node->pn_info,
("%s(): parent has different pn_info", __func__));
mtx_lock(&node->pn_info->pi_mutex);
if (parent->pn_nodes == node) {
parent->pn_nodes = node->pn_next;
} else {
rover = parent->pn_nodes;
while (rover->pn_next != NULL) {
if (rover->pn_next == node) {
rover->pn_next = node->pn_next;
break;
}
rover = rover->pn_next;
}
}
mtx_unlock(&node->pn_info->pi_mutex);
}
/* revoke vnodes and release memory */
pfs_disable(node);
FREE(node, M_PFSNODES);
return (0);
}
/*
* Mount a pseudofs instance
*/
int
pfs_mount(struct pfs_info *pi, struct mount *mp, struct thread *td)
{
struct statfs *sbp;
if (mp->mnt_flag & MNT_UPDATE)
return (EOPNOTSUPP);
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_data = (qaddr_t)pi;
vfs_getnewfsid(mp);
sbp = &mp->mnt_stat;
vfs_mountedfrom(mp, pi->pi_name);
sbp->f_bsize = PAGE_SIZE;
sbp->f_iosize = PAGE_SIZE;
sbp->f_blocks = 1;
sbp->f_bfree = 0;
sbp->f_bavail = 0;
sbp->f_files = 1;
sbp->f_ffree = 0;
return (0);
}
/*
* Unmount a pseudofs instance
*/
int
pfs_unmount(struct mount *mp, int mntflags, struct thread *td)
{
struct pfs_info *pi;
int error;
pi = (struct pfs_info *)mp->mnt_data;
/* XXX do stuff with pi... */
error = vflush(mp, 0, (mntflags & MNT_FORCE) ? FORCECLOSE : 0, td);
return (error);
}
/*
* Return a root vnode
*/
int
pfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td)
{
struct pfs_info *pi;
pi = (struct pfs_info *)mp->mnt_data;
return pfs_vncache_alloc(mp, vpp, pi->pi_root, NO_PID);
}
/*
* Return filesystem stats
*/
int
pfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
{
/* no-op: always called with mp->mnt_stat */
return (0);
}
/*
* Initialize a pseudofs instance
*/
int
pfs_init(struct pfs_info *pi, struct vfsconf *vfc)
{
struct pfs_node *root;
int error;
mtx_init(&pi->pi_mutex, "pseudofs", NULL, MTX_DEF);
/* set up the root diretory */
MALLOC(root, struct pfs_node *, sizeof *root,
M_PFSNODES, M_WAITOK|M_ZERO);
root->pn_type = pfstype_root;
root->pn_name[0] = '/';
root->pn_info = pi;
if (_pfs_fixup_dir(root) != 0) {
FREE(root, M_PFSNODES);
return (ENODEV); /* XXX not really the right errno */
}
pi->pi_root = root;
/* construct file hierarchy */
error = (pi->pi_init)(pi, vfc);
if (error) {
pfs_destroy(root);
pi->pi_root = NULL;
mtx_destroy(&pi->pi_mutex);
return (error);
}
pfs_fileno_init(pi);
if (bootverbose)
printf("%s registered\n", pi->pi_name);
return (0);
}
/*
* Destroy a pseudofs instance
*/
int
pfs_uninit(struct pfs_info *pi, struct vfsconf *vfc)
{
int error;
pfs_fileno_uninit(pi);
pfs_destroy(pi->pi_root);
pi->pi_root = NULL;
mtx_destroy(&pi->pi_mutex);
if (bootverbose)
printf("%s unregistered\n", pi->pi_name);
error = (pi->pi_uninit)(pi, vfc);
return (error);
}
/*
* Handle load / unload events
*/
static int
pfs_modevent(module_t mod, int evt, void *arg)
{
switch (evt) {
case MOD_LOAD:
pfs_vncache_load();
break;
case MOD_UNLOAD:
case MOD_SHUTDOWN:
pfs_vncache_unload();
break;
default:
return EOPNOTSUPP;
break;
}
return 0;
}
/*
* Module declaration
*/
static moduledata_t pseudofs_data = {
"pseudofs",
pfs_modevent,
NULL
};
DECLARE_MODULE(pseudofs, pseudofs_data, SI_SUB_EXEC, SI_ORDER_FIRST);
MODULE_VERSION(pseudofs, 1);