devfs_devs.c revision 85979
164880Sphk#define DEBUG 1 264880Sphk/* 364880Sphk * Copyright (c) 2000 464880Sphk * Poul-Henning Kamp. All rights reserved. 564880Sphk * 664880Sphk * Redistribution and use in source and binary forms, with or without 764880Sphk * modification, are permitted provided that the following conditions 864880Sphk * are met: 964880Sphk * 1. Redistributions of source code must retain the above copyright 1064880Sphk * notice, this list of conditions and the following disclaimer. 1164880Sphk * 2. Neither the name of the University nor the names of its contributors 1264880Sphk * may be used to endorse or promote products derived from this software 1364880Sphk * without specific prior written permission. 1464880Sphk * 1564880Sphk * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 1664880Sphk * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1764880Sphk * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1864880Sphk * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 1964880Sphk * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2064880Sphk * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2164880Sphk * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2264880Sphk * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2364880Sphk * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2464880Sphk * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2564880Sphk * SUCH DAMAGE. 2664880Sphk * 2764880Sphk * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36 2864880Sphk * 2964880Sphk * $FreeBSD: head/sys/fs/devfs/devfs_devs.c 85979 2001-11-03 16:53:24Z phk $ 3064880Sphk */ 3164880Sphk 3265515Sphk#include "opt_devfs.h" 3376554Sphk#ifndef NODEVFS 3465515Sphk 3564880Sphk#include <sys/param.h> 3664880Sphk#include <sys/systm.h> 3776166Smarkm#include <sys/conf.h> 3864880Sphk#include <sys/dirent.h> 3976166Smarkm#include <sys/kernel.h> 4076166Smarkm#include <sys/lock.h> 4164880Sphk#include <sys/malloc.h> 4276166Smarkm#include <sys/proc.h> 4365515Sphk#include <sys/sysctl.h> 4476166Smarkm#include <sys/vnode.h> 4564880Sphk 4665515Sphk#include <machine/atomic.h> 4765515Sphk 4864880Sphk#include <fs/devfs/devfs.h> 4964880Sphk 5065515Sphkstatic dev_t devfs_inot[NDEVFSINO]; 5165515Sphkstatic dev_t *devfs_overflow; 5265515Sphkstatic int devfs_ref[NDEVFSINO]; 5365515Sphkstatic int *devfs_refoverflow; 5465515Sphkstatic int devfs_nextino = 3; 5565515Sphkstatic int devfs_numino; 5665515Sphkstatic int devfs_topino; 5765515Sphkstatic int devfs_noverflowwant = NDEVFSOVERFLOW; 5865515Sphkstatic int devfs_noverflow; 5965515Sphkstatic unsigned devfs_generation; 6065515Sphk 6169767Sphkstatic void devfs_attemptoverflow(int insist); 6269767Sphkstatic struct devfs_dirent *devfs_find (struct devfs_dirent *dd, const char *name, int namelen); 6369767Sphk 6465515SphkSYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem"); 6565515SphkSYSCTL_UINT(_vfs_devfs, OID_AUTO, noverflow, CTLFLAG_RW, 6665515Sphk &devfs_noverflowwant, 0, "Size of DEVFS overflow table"); 6765515SphkSYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD, 6865515Sphk &devfs_generation, 0, "DEVFS generation number"); 6965515SphkSYSCTL_UINT(_vfs_devfs, OID_AUTO, inodes, CTLFLAG_RD, 7065515Sphk &devfs_numino, 0, "DEVFS inodes"); 7165515SphkSYSCTL_UINT(_vfs_devfs, OID_AUTO, topinode, CTLFLAG_RD, 7265515Sphk &devfs_topino, 0, "DEVFS highest inode#"); 7365515Sphk 7465515Sphkstatic int * 7565515Sphkdevfs_itor(int inode) 7665515Sphk{ 7765515Sphk if (inode < NDEVFSINO) 7865515Sphk return (&devfs_ref[inode]); 7965515Sphk else if (inode < NDEVFSINO + devfs_noverflow) 8065515Sphk return (&devfs_refoverflow[inode - NDEVFSINO]); 8165515Sphk else 8265515Sphk panic ("YRK!"); 8365515Sphk} 8465515Sphk 8565515Sphkstatic void 8665515Sphkdevfs_dropref(int inode) 8765515Sphk{ 8865515Sphk int *ip; 8965515Sphk 9065515Sphk ip = devfs_itor(inode); 9165515Sphk atomic_add_int(ip, -1); 9265515Sphk} 9365515Sphk 9465515Sphkstatic int 9565515Sphkdevfs_getref(int inode) 9665515Sphk{ 9765515Sphk int *ip, i, j; 9865515Sphk dev_t *dp; 9965515Sphk 10065515Sphk ip = devfs_itor(inode); 10165515Sphk dp = devfs_itod(inode); 10265515Sphk for (;;) { 10365515Sphk i = *ip; 10465515Sphk j = i + 1; 10565515Sphk if (!atomic_cmpset_int(ip, i, j)) 10665515Sphk continue; 10765515Sphk if (*dp != NULL) 10865515Sphk return (1); 10965515Sphk atomic_add_int(ip, -1); 11065515Sphk return(0); 11165515Sphk } 11265515Sphk} 11365515Sphk 11465515Sphkstruct devfs_dirent ** 11565515Sphkdevfs_itode (struct devfs_mount *dm, int inode) 11665515Sphk{ 11765515Sphk 11865515Sphk if (inode < NDEVFSINO) 11965515Sphk return (&dm->dm_dirent[inode]); 12065515Sphk if (devfs_overflow == NULL) 12165515Sphk return (NULL); 12265515Sphk if (inode < NDEVFSINO + devfs_noverflow) 12365515Sphk return (&dm->dm_overflow[inode - NDEVFSINO]); 12465515Sphk return (NULL); 12565515Sphk} 12665515Sphk 12765515Sphkdev_t * 12865515Sphkdevfs_itod (int inode) 12965515Sphk{ 13065515Sphk 13165515Sphk if (inode < NDEVFSINO) 13265515Sphk return (&devfs_inot[inode]); 13365515Sphk if (devfs_overflow == NULL) 13465515Sphk return (NULL); 13565515Sphk if (inode < NDEVFSINO + devfs_noverflow) 13665515Sphk return (&devfs_overflow[inode - NDEVFSINO]); 13765515Sphk return (NULL); 13865515Sphk} 13965515Sphk 14069767Sphkstatic void 14165515Sphkdevfs_attemptoverflow(int insist) 14265515Sphk{ 14365515Sphk dev_t **ot; 14465515Sphk int *or; 14565515Sphk int n, nb; 14665515Sphk 14765515Sphk /* Check if somebody beat us to it */ 14865515Sphk if (devfs_overflow != NULL) 14965515Sphk return; 15065515Sphk ot = NULL; 15165515Sphk or = NULL; 15265515Sphk n = devfs_noverflowwant; 15365515Sphk nb = sizeof (struct dev_t *) * n; 15469781Sdwmalone MALLOC(ot, dev_t **, nb, M_DEVFS, (insist ? M_WAITOK : M_NOWAIT) | M_ZERO); 15565515Sphk if (ot == NULL) 15665515Sphk goto bail; 15765515Sphk nb = sizeof (int) * n; 15869781Sdwmalone MALLOC(or, int *, nb, M_DEVFS, (insist ? M_WAITOK : M_NOWAIT) | M_ZERO); 15966877Sphk if (or == NULL) 16065515Sphk goto bail; 16166877Sphk if (!atomic_cmpset_ptr(&devfs_overflow, NULL, ot)) 16265515Sphk goto bail; 16365515Sphk devfs_refoverflow = or; 16465515Sphk devfs_noverflow = n; 16565515Sphk printf("DEVFS Overflow table with %d entries allocated when %d in use\n", n, devfs_numino); 16665515Sphk return; 16765515Sphk 16865515Sphkbail: 16965515Sphk /* Somebody beat us to it, or something went wrong. */ 17065515Sphk if (ot != NULL) 17165515Sphk FREE(ot, M_DEVFS); 17265515Sphk if (or != NULL) 17365515Sphk FREE(or, M_DEVFS); 17465515Sphk return; 17565515Sphk} 17665515Sphk 17769767Sphkstatic struct devfs_dirent * 17865132Sphkdevfs_find(struct devfs_dirent *dd, const char *name, int namelen) 17965132Sphk{ 18065132Sphk struct devfs_dirent *de; 18165132Sphk 18265132Sphk TAILQ_FOREACH(de, &dd->de_dlist, de_list) { 18365132Sphk if (namelen != de->de_dirent->d_namlen) 18465132Sphk continue; 18565132Sphk if (bcmp(name, de->de_dirent->d_name, namelen) != 0) 18665132Sphk continue; 18765132Sphk break; 18865132Sphk } 18965132Sphk return (de); 19065132Sphk} 19165132Sphk 19265132Sphkstruct devfs_dirent * 19364880Sphkdevfs_newdirent(char *name, int namelen) 19464880Sphk{ 19564880Sphk int i; 19664880Sphk struct devfs_dirent *de; 19764880Sphk struct dirent d; 19864880Sphk 19964880Sphk d.d_namlen = namelen; 20064880Sphk i = sizeof (*de) + GENERIC_DIRSIZ(&d); 20169781Sdwmalone MALLOC(de, struct devfs_dirent *, i, M_DEVFS, M_WAITOK | M_ZERO); 20264880Sphk de->de_dirent = (struct dirent *)(de + 1); 20364880Sphk de->de_dirent->d_namlen = namelen; 20464880Sphk de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d); 20571822Sphk bcopy(name, de->de_dirent->d_name, namelen); 20671822Sphk de->de_dirent->d_name[namelen] = '\0'; 20785979Sphk vfs_timestamp(&de->de_ctime); 20865051Sphk de->de_mtime = de->de_atime = de->de_ctime; 20965051Sphk de->de_links = 1; 21064880Sphk return (de); 21164880Sphk} 21264880Sphk 21365051Sphkstruct devfs_dirent * 21465051Sphkdevfs_vmkdir(char *name, int namelen, struct devfs_dirent *dotdot) 21564880Sphk{ 21665051Sphk struct devfs_dirent *dd; 21764880Sphk struct devfs_dirent *de; 21864880Sphk 21965051Sphk dd = devfs_newdirent(name, namelen); 22064880Sphk 22165051Sphk TAILQ_INIT(&dd->de_dlist); 22265051Sphk 22365051Sphk dd->de_dirent->d_type = DT_DIR; 22485979Sphk dd->de_mode = 0555; 22565051Sphk dd->de_links = 2; 22665051Sphk dd->de_dir = dd; 22765051Sphk 22864880Sphk de = devfs_newdirent(".", 1); 22964880Sphk de->de_dirent->d_type = DT_DIR; 23065051Sphk de->de_dir = dd; 23165051Sphk de->de_flags |= DE_DOT; 23265051Sphk TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list); 23365051Sphk 23465051Sphk de = devfs_newdirent("..", 2); 23565051Sphk de->de_dirent->d_type = DT_DIR; 23665051Sphk if (dotdot == NULL) 23765051Sphk de->de_dir = dd; 23865051Sphk else 23965051Sphk de->de_dir = dotdot; 24065051Sphk de->de_flags |= DE_DOTDOT; 24165051Sphk TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list); 24265051Sphk 24364880Sphk return (dd); 24464880Sphk} 24564880Sphk 24665051Sphkstatic void 24765051Sphkdevfs_delete(struct devfs_dirent *dd, struct devfs_dirent *de) 24864880Sphk{ 24964880Sphk 25064880Sphk if (de->de_symlink) { 25164880Sphk FREE(de->de_symlink, M_DEVFS); 25264880Sphk de->de_symlink = NULL; 25364880Sphk } 25466877Sphk if (de->de_vnode) 25564880Sphk de->de_vnode->v_data = NULL; 25665051Sphk TAILQ_REMOVE(&dd->de_dlist, de, de_list); 25764880Sphk FREE(de, M_DEVFS); 25864880Sphk} 25964880Sphk 26064880Sphkvoid 26165051Sphkdevfs_purge(struct devfs_dirent *dd) 26264880Sphk{ 26364880Sphk struct devfs_dirent *de; 26464880Sphk 26564880Sphk for (;;) { 26665051Sphk de = TAILQ_FIRST(&dd->de_dlist); 26764880Sphk if (de == NULL) 26864880Sphk break; 26964880Sphk devfs_delete(dd, de); 27064880Sphk } 27164880Sphk FREE(dd, M_DEVFS); 27264880Sphk} 27364880Sphk 27464880Sphk 27564880Sphkint 27664880Sphkdevfs_populate(struct devfs_mount *dm) 27764880Sphk{ 27864880Sphk int i, j; 27964880Sphk dev_t dev, pdev; 28065051Sphk struct devfs_dirent *dd; 28165515Sphk struct devfs_dirent *de, **dep; 28264880Sphk char *q, *s; 28364880Sphk 28466877Sphk if (dm->dm_generation == devfs_generation) 28565515Sphk return (0); 28683366Sjulian lockmgr(&dm->dm_lock, LK_UPGRADE, 0, curthread); 28765515Sphk if (devfs_noverflow && dm->dm_overflow == NULL) { 28865515Sphk i = devfs_noverflow * sizeof (struct devfs_dirent *); 28965515Sphk MALLOC(dm->dm_overflow, struct devfs_dirent **, i, 29069781Sdwmalone M_DEVFS, M_WAITOK | M_ZERO); 29165515Sphk } 29264880Sphk while (dm->dm_generation != devfs_generation) { 29364880Sphk dm->dm_generation = devfs_generation; 29465515Sphk for (i = 0; i <= devfs_topino; i++) { 29565515Sphk dev = *devfs_itod(i); 29665515Sphk dep = devfs_itode(dm, i); 29765515Sphk de = *dep; 29865051Sphk if (dev == NULL && de == DE_DELETED) { 29965515Sphk *dep = NULL; 30065051Sphk continue; 30165051Sphk } 30264880Sphk if (dev == NULL && de != NULL) { 30364880Sphk dd = de->de_dir; 30465515Sphk *dep = NULL; 30565051Sphk TAILQ_REMOVE(&dd->de_dlist, de, de_list); 30666877Sphk if (de->de_vnode) 30764880Sphk de->de_vnode->v_data = NULL; 30864880Sphk FREE(de, M_DEVFS); 30965515Sphk devfs_dropref(i); 31064880Sphk continue; 31164880Sphk } 31264880Sphk if (dev == NULL) 31364880Sphk continue; 31464880Sphk if (de != NULL) 31564880Sphk continue; 31665515Sphk if (!devfs_getref(i)) 31765515Sphk continue; 31864880Sphk dd = dm->dm_basedir; 31964880Sphk s = dev->si_name; 32065132Sphk for (;;) { 32165132Sphk for (q = s; *q != '/' && *q != '\0'; q++) 32265132Sphk continue; 32366877Sphk if (*q != '/') 32465132Sphk break; 32565132Sphk de = devfs_find(dd, s, q - s); 32665132Sphk if (de == NULL) { 32765132Sphk de = devfs_vmkdir(s, q - s, dd); 32865132Sphk de->de_inode = dm->dm_inode++; 32965132Sphk TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list); 33065132Sphk dd->de_links++; 33165051Sphk } 33265051Sphk s = q + 1; 33365051Sphk dd = de; 33464880Sphk } 33564880Sphk de = devfs_newdirent(s, q - s); 33664880Sphk if (dev->si_flags & SI_ALIAS) { 33764880Sphk de->de_inode = dm->dm_inode++; 33864880Sphk de->de_uid = 0; 33964880Sphk de->de_gid = 0; 34085979Sphk de->de_mode = 0755; 34164880Sphk de->de_dirent->d_type = DT_LNK; 34277215Sphk pdev = dev->si_parent; 34364880Sphk j = strlen(pdev->si_name) + 1; 34464880Sphk MALLOC(de->de_symlink, char *, j, M_DEVFS, M_WAITOK); 34564880Sphk bcopy(pdev->si_name, de->de_symlink, j); 34664880Sphk } else { 34764880Sphk de->de_inode = i; 34864880Sphk de->de_uid = dev->si_uid; 34964880Sphk de->de_gid = dev->si_gid; 35064880Sphk de->de_mode = dev->si_mode; 35164880Sphk de->de_dirent->d_type = DT_CHR; 35264880Sphk } 35365515Sphk *dep = de; 35465132Sphk de->de_dir = dd; 35565051Sphk TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list); 35664880Sphk#if 0 35764880Sphk printf("Add ino%d %s\n", i, dev->si_name); 35864880Sphk#endif 35964880Sphk } 36064880Sphk } 36183366Sjulian lockmgr(&dm->dm_lock, LK_DOWNGRADE, 0, curthread); 36264880Sphk return (0); 36364880Sphk} 36464880Sphk 36564880Sphkstatic void 36664880Sphkdevfs_create(dev_t dev) 36764880Sphk{ 36865515Sphk int ino, i, *ip; 36965515Sphk dev_t *dp; 37065515Sphk 37165515Sphk for (;;) { 37265515Sphk /* Grab the next inode number */ 37365515Sphk ino = devfs_nextino; 37465515Sphk i = ino + 1; 37565515Sphk /* wrap around when we reach the end */ 37665515Sphk if (i >= NDEVFSINO + devfs_noverflow) 37765515Sphk i = 3; 37865515Sphk if (!atomic_cmpset_int(&devfs_nextino, ino, i)) 37965515Sphk continue; 38065515Sphk 38165515Sphk /* see if it was occupied */ 38265515Sphk dp = devfs_itod(ino); 38365515Sphk if (dp == NULL) 38465515Sphk Debugger("dp == NULL\n"); 38565515Sphk if (*dp != NULL) 38665515Sphk continue; 38765515Sphk ip = devfs_itor(ino); 38865515Sphk if (ip == NULL) 38965515Sphk Debugger("ip == NULL\n"); 39065515Sphk if (*ip != 0) 39165515Sphk continue; 39265515Sphk 39365515Sphk if (!atomic_cmpset_ptr(dp, NULL, dev)) 39465515Sphk continue; 39565515Sphk 39665515Sphk dev->si_inode = ino; 39765515Sphk for (;;) { 39865515Sphk i = devfs_topino; 39965515Sphk if (i >= ino) 40065515Sphk break; 40165515Sphk if (atomic_cmpset_int(&devfs_topino, i, ino)) 40265515Sphk break; 40365515Sphk printf("failed topino %d %d\n", i, ino); 40465515Sphk } 40565515Sphk break; 40664880Sphk } 40765515Sphk 40865515Sphk atomic_add_int(&devfs_numino, 1); 40965515Sphk atomic_add_int(&devfs_generation, 1); 41065515Sphk if (devfs_overflow == NULL && devfs_numino + 100 > NDEVFSINO) 41165515Sphk devfs_attemptoverflow(0); 41264880Sphk} 41364880Sphk 41464880Sphkstatic void 41565374Sphkdevfs_destroy(dev_t dev) 41664880Sphk{ 41765515Sphk int ino, i; 41865515Sphk 41965515Sphk ino = dev->si_inode; 42065515Sphk dev->si_inode = 0; 42165515Sphk if (ino == 0) 42265515Sphk return; 42365515Sphk if (atomic_cmpset_ptr(devfs_itod(ino), dev, NULL)) { 42465515Sphk atomic_add_int(&devfs_generation, 1); 42565515Sphk atomic_add_int(&devfs_numino, -1); 42665515Sphk i = devfs_nextino; 42765515Sphk if (ino < i) 42865515Sphk atomic_cmpset_int(&devfs_nextino, i, ino); 42965515Sphk } 43064880Sphk} 43164880Sphk 43264880Sphkdevfs_create_t *devfs_create_hook = devfs_create; 43365374Sphkdevfs_destroy_t *devfs_destroy_hook = devfs_destroy; 43465374Sphkint devfs_present = 1; 43576554Sphk#endif 436