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freebsd/sys/fs/pseudofs/pseudofs.c
Poul-Henning Kamp def91cf267 Use vfs_mountedfrom().
Since VFS_STATFS() always calls the filesystem with mp->mnt_stat now, the
vfs_statfs method is now a no-op.  Explain this in a comment.
2004-12-06 20:52:46 +00:00

412 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.
*
* $FreeBSD$
*/
#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, 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_fileno_load();
pfs_vncache_load();
break;
case MOD_UNLOAD:
case MOD_SHUTDOWN:
pfs_vncache_unload();
pfs_fileno_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);