ops_cachefs.c revision 119679
1/* 2 * Copyright (c) 1997-2003 Erez Zadok 3 * Copyright (c) 1990 Jan-Simon Pendry 4 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine 5 * Copyright (c) 1990 The Regents of the University of California. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Jan-Simon Pendry at Imperial College, London. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgment: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * %W% (Berkeley) %G% 40 * 41 * $Id: ops_cachefs.c,v 1.3.2.3 2002/12/27 22:44:40 ezk Exp $ 42 * 43 */ 44 45/* 46 * Caching filesystem (Solaris 2.x) 47 */ 48 49#ifdef HAVE_CONFIG_H 50# include <config.h> 51#endif /* HAVE_CONFIG_H */ 52#include <am_defs.h> 53#include <amd.h> 54 55/* forward declarations */ 56static char *cachefs_match(am_opts *fo); 57static int cachefs_init(mntfs *mf); 58static int cachefs_fmount(mntfs *mf); 59static int cachefs_fumount(mntfs *mf); 60 61 62/* 63 * Ops structure 64 */ 65am_ops cachefs_ops = 66{ 67 "cachefs", 68 cachefs_match, 69 cachefs_init, 70 amfs_auto_fmount, 71 cachefs_fmount, 72 amfs_auto_fumount, 73 cachefs_fumount, 74 amfs_error_lookuppn, 75 amfs_error_readdir, 76 0, /* cachefs_readlink */ 77 0, /* post-mount actions */ 78 0, /* post-umount actions */ 79 find_amfs_auto_srvr, 80 FS_MKMNT | FS_NOTIMEOUT | FS_UBACKGROUND | FS_AMQINFO 81}; 82 83 84/* 85 * Check that f/s has all needed fields. 86 * Returns: matched string if found, NULL otherwise. 87 */ 88static char * 89cachefs_match(am_opts *fo) 90{ 91 /* sanity check */ 92 if (!fo->opt_rfs || !fo->opt_fs || !fo->opt_cachedir) { 93 plog(XLOG_USER, "cachefs: must specify cachedir, rfs, and fs"); 94 return NULL; 95 } 96 97#ifdef DEBUG 98 dlog("CACHEFS: using cache directory \"%s\"", fo->opt_cachedir); 99#endif /* DEBUG */ 100 101 /* determine magic cookie to put in mtab */ 102 return strdup(fo->opt_cachedir); 103} 104 105 106/* 107 * Initialize. 108 * Returns: 0 if OK, non-zero (errno) if failed. 109 */ 110static int 111cachefs_init(mntfs *mf) 112{ 113 /* 114 * Save cache directory name 115 */ 116 if (mf->mf_refc == 1) { 117 mf->mf_private = (voidp) strdup(mf->mf_fo->opt_cachedir); 118 mf->mf_prfree = (void (*)(voidp)) free; 119 } 120 121 return 0; 122} 123 124 125/* 126 * mntpt is the mount point ($fs) [XXX: was 'dir'] 127 * backdir is the mounted pathname ($rfs) [XXX: was 'fs_name'] 128 * cachedir is the cache directory ($cachedir) 129 */ 130static int 131mount_cachefs(char *mntpt, char *backdir, char *cachedir, char *opts) 132{ 133 cachefs_args_t ca; 134 mntent_t mnt; 135 int flags; 136 char *cp; 137 MTYPE_TYPE type = MOUNT_TYPE_CACHEFS; /* F/S mount type */ 138 139 memset((voidp) &ca, 0, sizeof(ca)); /* Paranoid */ 140 141 /* 142 * Fill in the mount structure 143 */ 144 memset((voidp) &mnt, 0, sizeof(mnt)); 145 mnt.mnt_dir = mntpt; 146 mnt.mnt_fsname = backdir; 147 mnt.mnt_type = MNTTAB_TYPE_CACHEFS; 148 mnt.mnt_opts = opts; 149 150 flags = compute_mount_flags(&mnt); 151 152 /* Fill in cachefs mount arguments */ 153 154 /* 155 * XXX: Caveats 156 * (1) cache directory is NOT checked for sanity beforehand, nor is it 157 * purged. Maybe it should be purged first? 158 * (2) cache directory is NOT locked. Should we? 159 */ 160 161 /* mount flags */ 162 ca.cfs_options.opt_flags = CFS_WRITE_AROUND | CFS_ACCESS_BACKFS; 163 /* cache population size */ 164 ca.cfs_options.opt_popsize = DEF_POP_SIZE; /* default: 64K */ 165 /* filegrp size */ 166 ca.cfs_options.opt_fgsize = DEF_FILEGRP_SIZE; /* default: 256 */ 167 168 /* CFS ID for file system (must be unique) */ 169 ca.cfs_fsid = cachedir; 170 171 /* CFS fscdir name */ 172 memset(ca.cfs_cacheid, 0, sizeof(ca.cfs_cacheid)); 173 /* append cacheid and mountpoint */ 174 sprintf(ca.cfs_cacheid, "%s:%s", ca.cfs_fsid, mntpt); 175 /* convert '/' to '_' (Solaris does that...) */ 176 cp = ca.cfs_cacheid; 177 while ((cp = strpbrk(cp, "/")) != NULL) 178 *cp = '_'; 179 180 /* path for this cache dir */ 181 ca.cfs_cachedir = cachedir; 182 183 /* back filesystem dir */ 184 ca.cfs_backfs = backdir; 185 186 /* same as nfs values (XXX: need to handle these options) */ 187 ca.cfs_acregmin = 0; 188 ca.cfs_acregmax = 0; 189 ca.cfs_acdirmin = 0; 190 ca.cfs_acdirmax = 0; 191 192 /* 193 * Call generic mount routine 194 */ 195 return mount_fs(&mnt, flags, (caddr_t) &ca, 0, type, 0, NULL, mnttab_file_name); 196} 197 198 199static int 200cachefs_fmount(mntfs *mf) 201{ 202 int error; 203 204 error = mount_cachefs(mf->mf_mount, 205 mf->mf_fo->opt_rfs, 206 mf->mf_fo->opt_cachedir, 207 mf->mf_mopts); 208 if (error) { 209 errno = error; 210 /* according to Solaris, if errno==ESRCH, "options to not match" */ 211 if (error == ESRCH) 212 plog(XLOG_ERROR, "mount_cachefs: options to no match: %m"); 213 else 214 plog(XLOG_ERROR, "mount_cachefs: %m"); 215 return error; 216 } 217 218 return 0; 219} 220 221 222static int 223cachefs_fumount(mntfs *mf) 224{ 225 int error; 226 227 error = UMOUNT_FS(mf->mf_mount, mnttab_file_name); 228 229 /* 230 * In the case of cachefs, we must fsck the cache directory. Otherwise, 231 * it will remain inconsistent, and the next cachefs mount will fail 232 * with the error "no space left on device" (ENOSPC). 233 * 234 * XXX: this is hacky! use fork/exec/wait instead... 235 */ 236 if (!error) { 237 char *cachedir = NULL; 238 char cmd[128]; 239 240 cachedir = (char *) mf->mf_private; 241 plog(XLOG_INFO, "running fsck on cache directory \"%s\"", cachedir); 242 sprintf(cmd, "fsck -F cachefs %s", cachedir); 243 system(cmd); 244 } 245 246 return error; 247} 248