/* $OpenBSD: tmpfs_mem.c,v 1.2 2013/06/03 10:37:02 espie Exp $ */ /* $NetBSD: tmpfs_mem.c,v 1.4 2011/05/24 01:09:47 rmind Exp $ */ /* * Copyright (c) 2010, 2011 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Mindaugas Rasiukevicius. * * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``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 FOUNDATION 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. */ /* * tmpfs memory allocation routines. * Implements memory usage accounting and limiting. */ #if 0 #include <sys/cdefs.h> __KERNEL_RCSID(0, "$NetBSD: tmpfs_mem.c,v 1.4 2011/05/24 01:09:47 rmind Exp $"); #endif #include <sys/param.h> #include <sys/namei.h> #include <sys/pool.h> #include <sys/vnode.h> #include <sys/malloc.h> #include <tmpfs/tmpfs.h> extern struct pool tmpfs_dirent_pool; extern struct pool tmpfs_node_pool; void tmpfs_mntmem_init(struct tmpfs_mount *mp, uint64_t memlimit) { rw_init(&mp->tm_acc_lock, "tacclk"); mp->tm_mem_limit = memlimit; mp->tm_bytes_used = 0; } void tmpfs_mntmem_destroy(struct tmpfs_mount *mp) { KASSERT(mp->tm_bytes_used == 0); /* mutex_destroy(&mp->tm_acc_lock); */ } /* * tmpfs_mem_info: return the number of available memory pages. * * => If 'total' is true, then return _total_ amount of pages. * => If false, then return the amount of _free_ memory pages. * * Remember to remove TMPFS_PAGES_RESERVED from the returned value to avoid * excessive memory usage. */ size_t tmpfs_mem_info(int total) { int size = 0; /* XXX: unlocked */ size += uvmexp.swpages; if (!total) { size -= uvmexp.swpgonly; } size += uvmexp.free; /* size += uvmexp.filepages; */ if (size > uvmexp.wired) { size -= uvmexp.wired; } else { size = 0; } KASSERT(size >= 0); return (size_t)size; } uint64_t tmpfs_bytes_max(struct tmpfs_mount *mp) { size_t freepages = tmpfs_mem_info(0); uint64_t avail_mem; if (freepages < TMPFS_PAGES_RESERVED) { freepages = 0; } else { freepages -= TMPFS_PAGES_RESERVED; } avail_mem = round_page(mp->tm_bytes_used) + (freepages << PAGE_SHIFT); return MIN(mp->tm_mem_limit, avail_mem); } uint64_t tmpfs_pages_avail(struct tmpfs_mount *mp) { return (tmpfs_bytes_max(mp) - mp->tm_bytes_used) >> PAGE_SHIFT; } int tmpfs_mem_incr(struct tmpfs_mount *mp, size_t sz) { uint64_t lim; rw_enter_write(&mp->tm_acc_lock); lim = tmpfs_bytes_max(mp); if (mp->tm_bytes_used + sz >= lim) { rw_exit_write(&mp->tm_acc_lock); return 0; } mp->tm_bytes_used += sz; rw_exit_write(&mp->tm_acc_lock); return 1; } void tmpfs_mem_decr(struct tmpfs_mount *mp, size_t sz) { rw_enter_write(&mp->tm_acc_lock); KASSERT(mp->tm_bytes_used >= sz); mp->tm_bytes_used -= sz; rw_exit_write(&mp->tm_acc_lock); } struct tmpfs_dirent * tmpfs_dirent_get(struct tmpfs_mount *mp) { if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_dirent))) { return NULL; } return pool_get(&tmpfs_dirent_pool, PR_WAITOK); } void tmpfs_dirent_put(struct tmpfs_mount *mp, struct tmpfs_dirent *de) { tmpfs_mem_decr(mp, sizeof(struct tmpfs_dirent)); pool_put(&tmpfs_dirent_pool, de); } struct tmpfs_node * tmpfs_node_get(struct tmpfs_mount *mp) { mp->tm_nodes_cnt++; if (mp->tm_nodes_cnt > mp->tm_nodes_max) { mp->tm_nodes_cnt--; return NULL; } if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_node))) { return NULL; } return pool_get(&tmpfs_node_pool, PR_WAITOK); } void tmpfs_node_put(struct tmpfs_mount *mp, struct tmpfs_node *tn) { mp->tm_nodes_cnt--; tmpfs_mem_decr(mp, sizeof(struct tmpfs_node)); pool_put(&tmpfs_node_pool, tn); } /* * Quantum size to round-up the tmpfs names in order to reduce re-allocations. */ #define TMPFS_NAME_QUANTUM (32) #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ char * tmpfs_strname_alloc(struct tmpfs_mount *mp, size_t len) { const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); KASSERT(sz > 0 && sz <= 1024); if (!tmpfs_mem_incr(mp, sz)) { return NULL; } return malloc(sz, M_TEMP, M_WAITOK); /* XXX */ } void tmpfs_strname_free(struct tmpfs_mount *mp, char *str, size_t len) { const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); KASSERT(sz > 0 && sz <= 1024); tmpfs_mem_decr(mp, sz); free(str, M_TEMP); } int tmpfs_strname_neqlen(struct componentname *fcnp, struct componentname *tcnp) { const size_t fln = roundup2(fcnp->cn_namelen, TMPFS_NAME_QUANTUM); const size_t tln = roundup2(tcnp->cn_namelen, TMPFS_NAME_QUANTUM); return (fln != tln) || memcmp(fcnp->cn_nameptr, tcnp->cn_nameptr, fln); }