77465d9390
Requested by: bde
457 lines
10 KiB
C
457 lines
10 KiB
C
/*-
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* Copyright (c) 2001 Dag-Erling Coïdan Smørgrav
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer
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* in this position and unchanged.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_pseudofs.h"
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/systm.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/mount.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/sbuf.h>
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#include <sys/sysctl.h>
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#include <sys/vnode.h>
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#include <fs/pseudofs/pseudofs.h>
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#include <fs/pseudofs/pseudofs_internal.h>
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static MALLOC_DEFINE(M_PFSNODES, "pfs_nodes", "pseudofs nodes");
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SYSCTL_NODE(_vfs, OID_AUTO, pfs, CTLFLAG_RW, 0,
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"pseudofs");
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int pfs_trace;
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SYSCTL_INT(_vfs_pfs, OID_AUTO, trace, CTLFLAG_RW, &pfs_trace, 0,
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"enable tracing of pseudofs vnode operations");
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#if PFS_FSNAMELEN != MFSNAMELEN
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#error "PFS_FSNAMELEN is not equal to MFSNAMELEN"
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#endif
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/*
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* Allocate and initialize a node
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*/
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static struct pfs_node *
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pfs_alloc_node(struct pfs_info *pi, const char *name, pfs_type_t type)
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{
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struct pfs_node *pn;
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KASSERT(strlen(name) < PFS_NAMELEN,
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("%s(): node name is too long", __func__));
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MALLOC(pn, struct pfs_node *, sizeof *pn,
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M_PFSNODES, M_WAITOK|M_ZERO);
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mtx_init(&pn->pn_mutex, "pfs_node", NULL, MTX_DEF | MTX_DUPOK);
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strlcpy(pn->pn_name, name, sizeof pn->pn_name);
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pn->pn_type = type;
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pn->pn_info = pi;
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return (pn);
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}
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/*
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* Add a node to a directory
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*/
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static void
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pfs_add_node(struct pfs_node *parent, struct pfs_node *pn)
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{
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#ifdef INVARIANTS
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struct pfs_node *iter;
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#endif
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KASSERT(parent != NULL,
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("%s(): parent is NULL", __func__));
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KASSERT(pn->pn_parent == NULL,
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("%s(): node already has a parent", __func__));
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KASSERT(parent->pn_info != NULL,
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("%s(): parent has no pn_info", __func__));
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KASSERT(parent->pn_type == pfstype_dir ||
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parent->pn_type == pfstype_procdir ||
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parent->pn_type == pfstype_root,
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("%s(): parent is not a directory", __func__));
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#ifdef INVARIANTS
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/* XXX no locking! */
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if (pn->pn_type == pfstype_procdir)
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for (iter = parent; iter != NULL; iter = iter->pn_parent)
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KASSERT(iter->pn_type != pfstype_procdir,
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("%s(): nested process directories", __func__));
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for (iter = parent->pn_nodes; iter != NULL; iter = iter->pn_next) {
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KASSERT(strcmp(pn->pn_name, iter->pn_name) != 0,
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("%s(): homonymous siblings", __func__));
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if (pn->pn_type == pfstype_procdir)
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KASSERT(iter->pn_type != pfstype_procdir,
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("%s(): sibling process directories", __func__));
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}
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#endif
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pn->pn_parent = parent;
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pfs_fileno_alloc(pn);
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pfs_lock(parent);
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pn->pn_next = parent->pn_nodes;
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if ((parent->pn_flags & PFS_PROCDEP) != 0)
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pn->pn_flags |= PFS_PROCDEP;
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parent->pn_nodes = pn;
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pfs_unlock(parent);
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}
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/*
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* Detach a node from its aprent
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*/
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static void
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pfs_detach_node(struct pfs_node *pn)
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{
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struct pfs_node *parent = pn->pn_parent;
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struct pfs_node **iter;
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KASSERT(parent != NULL, ("%s(): node has no parent", __func__));
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KASSERT(parent->pn_info == pn->pn_info,
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("%s(): parent has different pn_info", __func__));
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pfs_lock(parent);
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iter = &parent->pn_nodes;
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while (*iter != NULL) {
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if (*iter == pn) {
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*iter = pn->pn_next;
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break;
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}
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iter = &(*iter)->pn_next;
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}
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pn->pn_parent = NULL;
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pfs_unlock(parent);
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}
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/*
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* Add . and .. to a directory
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*/
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static void
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pfs_fixup_dir(struct pfs_node *parent)
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{
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struct pfs_node *pn;
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pn = pfs_alloc_node(parent->pn_info, ".", pfstype_this);
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pfs_add_node(parent, pn);
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pn = pfs_alloc_node(parent->pn_info, "..", pfstype_parent);
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pfs_add_node(parent, pn);
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}
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/*
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* Create a directory
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*/
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struct pfs_node *
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pfs_create_dir(struct pfs_node *parent, const char *name,
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pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy,
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int flags)
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{
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struct pfs_node *pn;
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pn = pfs_alloc_node(parent->pn_info, name,
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(flags & PFS_PROCDEP) ? pfstype_procdir : pfstype_dir);
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pn->pn_attr = attr;
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pn->pn_vis = vis;
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pn->pn_destroy = destroy;
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pn->pn_flags = flags;
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pfs_add_node(parent, pn);
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pfs_fixup_dir(pn);
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return (pn);
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}
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/*
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* Create a file
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*/
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struct pfs_node *
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pfs_create_file(struct pfs_node *parent, const char *name, pfs_fill_t fill,
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pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy,
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int flags)
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{
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struct pfs_node *pn;
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pn = pfs_alloc_node(parent->pn_info, name, pfstype_file);
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pn->pn_fill = fill;
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pn->pn_attr = attr;
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pn->pn_vis = vis;
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pn->pn_destroy = destroy;
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pn->pn_flags = flags;
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pfs_add_node(parent, pn);
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return (pn);
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}
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/*
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* Create a symlink
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*/
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struct pfs_node *
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pfs_create_link(struct pfs_node *parent, const char *name, pfs_fill_t fill,
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pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy,
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int flags)
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{
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struct pfs_node *pn;
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pn = pfs_alloc_node(parent->pn_info, name, pfstype_symlink);
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pn->pn_fill = fill;
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pn->pn_attr = attr;
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pn->pn_vis = vis;
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pn->pn_destroy = destroy;
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pn->pn_flags = flags;
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pfs_add_node(parent, pn);
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return (pn);
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}
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/*
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* Locate a node by name
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*/
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struct pfs_node *
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pfs_find_node(struct pfs_node *parent, const char *name)
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{
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struct pfs_node *pn;
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pfs_lock(parent);
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for (pn = parent->pn_nodes; pn != NULL; pn = pn->pn_next)
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if (strcmp(pn->pn_name, name) == 0)
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break;
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pfs_unlock(parent);
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return (pn);
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}
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/*
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* Destroy a node and all its descendants. If the node to be destroyed
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* has a parent, the parent's mutex must be held.
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*/
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int
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pfs_destroy(struct pfs_node *pn)
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{
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struct pfs_node *iter;
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KASSERT(pn != NULL,
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("%s(): node is NULL", __func__));
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KASSERT(pn->pn_info != NULL,
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("%s(): node has no pn_info", __func__));
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if (pn->pn_parent)
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pfs_detach_node(pn);
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/* destroy children */
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if (pn->pn_type == pfstype_dir ||
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pn->pn_type == pfstype_procdir ||
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pn->pn_type == pfstype_root) {
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pfs_lock(pn);
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while (pn->pn_nodes != NULL) {
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iter = pn->pn_nodes;
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pn->pn_nodes = iter->pn_next;
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iter->pn_parent = NULL;
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pfs_unlock(pn);
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pfs_destroy(iter);
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pfs_lock(pn);
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}
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pfs_unlock(pn);
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}
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/* revoke vnodes and fileno */
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pfs_purge(pn);
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/* callback to free any private resources */
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if (pn->pn_destroy != NULL)
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pn_destroy(pn);
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/* destroy the node */
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pfs_fileno_free(pn);
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mtx_destroy(&pn->pn_mutex);
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FREE(pn, M_PFSNODES);
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return (0);
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}
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/*
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* Mount a pseudofs instance
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*/
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int
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pfs_mount(struct pfs_info *pi, struct mount *mp, struct thread *td)
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{
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struct statfs *sbp;
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if (mp->mnt_flag & MNT_UPDATE)
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return (EOPNOTSUPP);
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MNT_ILOCK(mp);
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mp->mnt_flag |= MNT_LOCAL;
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mp->mnt_kern_flag |= MNTK_MPSAFE;
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MNT_IUNLOCK(mp);
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mp->mnt_data = pi;
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vfs_getnewfsid(mp);
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sbp = &mp->mnt_stat;
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vfs_mountedfrom(mp, pi->pi_name);
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sbp->f_bsize = PAGE_SIZE;
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sbp->f_iosize = PAGE_SIZE;
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sbp->f_blocks = 1;
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sbp->f_bfree = 0;
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sbp->f_bavail = 0;
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sbp->f_files = 1;
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sbp->f_ffree = 0;
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return (0);
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}
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/*
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* Compatibility shim for old mount(2) system call
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*/
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int
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pfs_cmount(struct mntarg *ma, void *data, int flags, struct thread *td)
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{
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int error;
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error = kernel_mount(ma, flags);
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return (error);
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}
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/*
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* Unmount a pseudofs instance
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*/
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int
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pfs_unmount(struct mount *mp, int mntflags, struct thread *td)
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{
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int error;
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error = vflush(mp, 0, (mntflags & MNT_FORCE) ? FORCECLOSE : 0, td);
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return (error);
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}
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/*
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* Return a root vnode
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*/
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int
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pfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td)
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{
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struct pfs_info *pi;
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pi = (struct pfs_info *)mp->mnt_data;
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return (pfs_vncache_alloc(mp, vpp, pi->pi_root, NO_PID));
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}
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/*
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* Return filesystem stats
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*/
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int
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pfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
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{
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/* no-op: always called with mp->mnt_stat */
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return (0);
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}
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/*
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* Initialize a pseudofs instance
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*/
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int
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pfs_init(struct pfs_info *pi, struct vfsconf *vfc)
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{
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struct pfs_node *root;
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int error;
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mtx_assert(&Giant, MA_OWNED);
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pfs_fileno_init(pi);
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/* set up the root diretory */
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root = pfs_alloc_node(pi, "/", pfstype_root);
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pi->pi_root = root;
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pfs_fileno_alloc(root);
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pfs_fixup_dir(root);
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/* construct file hierarchy */
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error = (pi->pi_init)(pi, vfc);
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if (error) {
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pfs_destroy(root);
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pi->pi_root = NULL;
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return (error);
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}
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if (bootverbose)
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printf("%s registered\n", pi->pi_name);
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return (0);
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}
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/*
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* Destroy a pseudofs instance
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*/
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int
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pfs_uninit(struct pfs_info *pi, struct vfsconf *vfc)
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{
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int error;
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mtx_assert(&Giant, MA_OWNED);
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pfs_destroy(pi->pi_root);
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pi->pi_root = NULL;
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pfs_fileno_uninit(pi);
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if (bootverbose)
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printf("%s unregistered\n", pi->pi_name);
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error = (pi->pi_uninit)(pi, vfc);
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return (error);
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}
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/*
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* Handle load / unload events
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*/
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static int
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pfs_modevent(module_t mod, int evt, void *arg)
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{
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switch (evt) {
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case MOD_LOAD:
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pfs_vncache_load();
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break;
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case MOD_UNLOAD:
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case MOD_SHUTDOWN:
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pfs_vncache_unload();
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break;
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default:
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return EOPNOTSUPP;
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break;
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}
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return 0;
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}
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/*
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* Module declaration
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*/
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static moduledata_t pseudofs_data = {
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"pseudofs",
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pfs_modevent,
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NULL
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};
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DECLARE_MODULE(pseudofs, pseudofs_data, SI_SUB_EXEC, SI_ORDER_FIRST);
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MODULE_VERSION(pseudofs, 1);
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