285 lines
6.8 KiB
C
285 lines
6.8 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/mutex.h>
|
|
#include <sys/sysctl.h>
|
|
|
|
#include <machine/limits.h>
|
|
|
|
#include <fs/pseudofs/pseudofs.h>
|
|
#include <fs/pseudofs/pseudofs_internal.h>
|
|
|
|
static MALLOC_DEFINE(M_PFSFILENO, "pfs_fileno", "pseudofs fileno bitmap");
|
|
|
|
static struct mtx pfs_fileno_mutex;
|
|
|
|
#define PFS_BITMAP_SIZE 4096
|
|
#define PFS_SLOT_BITS (int)(sizeof(unsigned int) * CHAR_BIT)
|
|
#define PFS_BITMAP_BITS (PFS_BITMAP_SIZE * PFS_SLOT_BITS)
|
|
struct pfs_bitmap {
|
|
u_int32_t pb_offset;
|
|
int pb_used;
|
|
unsigned int pb_bitmap[PFS_BITMAP_SIZE];
|
|
struct pfs_bitmap *pb_next;
|
|
};
|
|
|
|
/*
|
|
* Initialization
|
|
*/
|
|
void
|
|
pfs_fileno_load(void)
|
|
{
|
|
mtx_init(&pfs_fileno_mutex, "pseudofs_fileno", MTX_DEF);
|
|
}
|
|
|
|
/*
|
|
* Teardown
|
|
*/
|
|
void
|
|
pfs_fileno_unload(void)
|
|
{
|
|
mtx_destroy(&pfs_fileno_mutex);
|
|
}
|
|
|
|
/*
|
|
* Initialize fileno bitmap
|
|
*/
|
|
void
|
|
pfs_fileno_init(struct pfs_info *pi)
|
|
{
|
|
struct pfs_bitmap *pb;
|
|
|
|
MALLOC(pb, struct pfs_bitmap *, sizeof *pb,
|
|
M_PFSFILENO, M_WAITOK|M_ZERO);
|
|
|
|
mtx_lock(&pi->pi_mutex);
|
|
|
|
pb->pb_bitmap[0] = 07;
|
|
pb->pb_used = 3;
|
|
pi->pi_bitmap = pb;
|
|
pi->pi_root->pn_fileno = 2;
|
|
|
|
mtx_unlock(&pi->pi_mutex);
|
|
}
|
|
|
|
/*
|
|
* Tear down fileno bitmap
|
|
*/
|
|
void
|
|
pfs_fileno_uninit(struct pfs_info *pi)
|
|
{
|
|
struct pfs_bitmap *pb, *npb;
|
|
int used;
|
|
|
|
mtx_lock(&pi->pi_mutex);
|
|
|
|
pb = pi->pi_bitmap;
|
|
pi->pi_bitmap = NULL;
|
|
|
|
mtx_unlock(&pi->pi_mutex);
|
|
|
|
for (used = 0; pb; pb = npb) {
|
|
npb = pb->pb_next;
|
|
used += pb->pb_used;
|
|
FREE(pb, M_PFSFILENO);
|
|
}
|
|
#if 0
|
|
/* we currently don't reclaim filenos */
|
|
if (used > 2)
|
|
printf("WARNING: %d file numbers still in use\n", used);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Get the next available file number
|
|
*/
|
|
static u_int32_t
|
|
pfs_get_fileno(struct pfs_info *pi)
|
|
{
|
|
struct pfs_bitmap *pb, *ppb;
|
|
u_int32_t fileno;
|
|
unsigned int *p;
|
|
int i;
|
|
|
|
mtx_lock(&pi->pi_mutex);
|
|
|
|
/* look for the first page with free bits */
|
|
for (ppb = NULL, pb = pi->pi_bitmap; pb; ppb = pb, pb = pb->pb_next)
|
|
if (pb->pb_used != PFS_BITMAP_BITS)
|
|
break;
|
|
|
|
/* out of pages? */
|
|
if (pb == NULL) {
|
|
mtx_unlock(&pi->pi_mutex);
|
|
MALLOC(pb, struct pfs_bitmap *, sizeof *pb,
|
|
M_PFSFILENO, M_WAITOK|M_ZERO);
|
|
mtx_lock(&pi->pi_mutex);
|
|
/* protect against possible race */
|
|
while (ppb->pb_next)
|
|
ppb = ppb->pb_next;
|
|
pb->pb_offset = ppb->pb_offset + PFS_BITMAP_BITS;
|
|
ppb->pb_next = pb;
|
|
}
|
|
|
|
/* find the first free slot */
|
|
for (i = 0; i < PFS_BITMAP_SIZE; ++i)
|
|
if (pb->pb_bitmap[i] != UINT_MAX)
|
|
break;
|
|
|
|
/* find the first available bit and flip it */
|
|
fileno = pb->pb_offset + i * PFS_SLOT_BITS;
|
|
p = &pb->pb_bitmap[i];
|
|
for (i = 0; i < PFS_SLOT_BITS; ++i, ++fileno)
|
|
if ((*p & (unsigned int)(1 << i)) == 0)
|
|
break;
|
|
KASSERT(i < PFS_SLOT_BITS,
|
|
("slot has free bits, yet doesn't"));
|
|
*p |= (unsigned int)(1 << i);
|
|
++pb->pb_used;
|
|
|
|
mtx_unlock(&pi->pi_mutex);
|
|
|
|
return fileno;
|
|
}
|
|
|
|
/*
|
|
* Free a file number
|
|
*/
|
|
static void
|
|
pfs_free_fileno(struct pfs_info *pi, u_int32_t fileno)
|
|
{
|
|
struct pfs_bitmap *pb;
|
|
unsigned int *p;
|
|
int i;
|
|
|
|
mtx_lock(&pi->pi_mutex);
|
|
|
|
/* find the right page */
|
|
for (pb = pi->pi_bitmap;
|
|
pb && fileno >= PFS_BITMAP_BITS;
|
|
pb = pb->pb_next, fileno -= PFS_BITMAP_BITS)
|
|
/* nothing */ ;
|
|
KASSERT(pb,
|
|
("fileno isn't in any bitmap"));
|
|
|
|
/* find the right bit in the right slot and flip it */
|
|
p = &pb->pb_bitmap[fileno / PFS_SLOT_BITS];
|
|
i = fileno % PFS_SLOT_BITS;
|
|
KASSERT(*p & (unsigned int)(1 << i),
|
|
("fileno is already free"));
|
|
*p &= ~((unsigned int)(1 << i));
|
|
--pb->pb_used;
|
|
|
|
mtx_unlock(&pi->pi_mutex);
|
|
printf("pfs_free_fileno(): reclaimed %d\n", fileno);
|
|
}
|
|
|
|
/*
|
|
* Allocate a file number
|
|
*/
|
|
void
|
|
pfs_fileno_alloc(struct pfs_info *pi, struct pfs_node *pn)
|
|
{
|
|
/* make sure our parent has a file number */
|
|
if (pn->pn_parent && !pn->pn_parent->pn_fileno)
|
|
pfs_fileno_alloc(pi, pn->pn_parent);
|
|
|
|
switch (pn->pn_type) {
|
|
case pfstype_root:
|
|
case pfstype_dir:
|
|
case pfstype_file:
|
|
case pfstype_symlink:
|
|
case pfstype_procdir:
|
|
pn->pn_fileno = pfs_get_fileno(pi);
|
|
break;
|
|
case pfstype_this:
|
|
KASSERT(pn->pn_parent != NULL,
|
|
("pfstype_this node has no parent"));
|
|
pn->pn_fileno = pn->pn_parent->pn_fileno;
|
|
break;
|
|
case pfstype_parent:
|
|
KASSERT(pn->pn_parent != NULL,
|
|
("pfstype_parent node has no parent"));
|
|
if (pn->pn_parent == pi->pi_root) {
|
|
pn->pn_fileno = pn->pn_parent->pn_fileno;
|
|
break;
|
|
}
|
|
KASSERT(pn->pn_parent->pn_parent != NULL,
|
|
("pfstype_parent node has no grandparent"));
|
|
pn->pn_fileno = pn->pn_parent->pn_parent->pn_fileno;
|
|
break;
|
|
case pfstype_none:
|
|
KASSERT(0,
|
|
("pfs_fileno_alloc() called for pfstype_none node"));
|
|
break;
|
|
}
|
|
|
|
#if 0
|
|
printf("pfs_fileno_alloc(): %s: ", pi->pi_name);
|
|
if (pn->pn_parent) {
|
|
if (pn->pn_parent->pn_parent) {
|
|
printf("%s/", pn->pn_parent->pn_parent->pn_name);
|
|
}
|
|
printf("%s/", pn->pn_parent->pn_name);
|
|
}
|
|
printf("%s -> %d\n", pn->pn_name, pn->pn_fileno);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Release a file number
|
|
*/
|
|
void
|
|
pfs_fileno_free(struct pfs_info *pi, struct pfs_node *pn)
|
|
{
|
|
switch (pn->pn_type) {
|
|
case pfstype_root:
|
|
case pfstype_dir:
|
|
case pfstype_file:
|
|
case pfstype_symlink:
|
|
case pfstype_procdir:
|
|
pfs_free_fileno(pi, pn->pn_fileno);
|
|
break;
|
|
case pfstype_this:
|
|
case pfstype_parent:
|
|
/* ignore these, as they don't "own" their file number */
|
|
break;
|
|
case pfstype_none:
|
|
KASSERT(0,
|
|
("pfs_fileno_free() called for pfstype_none node"));
|
|
break;
|
|
}
|
|
}
|