| 1 | /* |
| 2 | * Copyright (c) 1982 Regents of the University of California. |
| 3 | * All rights reserved. The Berkeley software License Agreement |
| 4 | * specifies the terms and conditions for redistribution. |
| 5 | * |
| 6 | * @(#)ufs_vfsops.c 6.13 (Berkeley) %G% |
| 7 | */ |
| 8 | |
| 9 | #include "param.h" |
| 10 | #include "systm.h" |
| 11 | #include "dir.h" |
| 12 | #include "user.h" |
| 13 | #include "inode.h" |
| 14 | #include "proc.h" |
| 15 | #include "fs.h" |
| 16 | #include "buf.h" |
| 17 | #include "mount.h" |
| 18 | #include "file.h" |
| 19 | #include "conf.h" |
| 20 | |
| 21 | smount() |
| 22 | { |
| 23 | register struct a { |
| 24 | char *fspec; |
| 25 | char *freg; |
| 26 | int ronly; |
| 27 | } *uap = (struct a *)u.u_ap; |
| 28 | dev_t dev; |
| 29 | register struct inode *ip; |
| 30 | register struct fs *fs; |
| 31 | register struct nameidata *ndp = &u.u_nd; |
| 32 | u_int len; |
| 33 | |
| 34 | u.u_error = getmdev(&dev, uap->fspec); |
| 35 | if (u.u_error) |
| 36 | return; |
| 37 | ndp->ni_nameiop = LOOKUP | NOCACHE | FOLLOW; |
| 38 | ndp->ni_segflg = UIO_USERSPACE; |
| 39 | ndp->ni_dirp = (caddr_t)uap->freg; |
| 40 | ip = namei(ndp); |
| 41 | if (ip == NULL) |
| 42 | return; |
| 43 | if (ip->i_count != 1) { |
| 44 | iput(ip); |
| 45 | u.u_error = EBUSY; |
| 46 | return; |
| 47 | } |
| 48 | if ((ip->i_mode&IFMT) != IFDIR) { |
| 49 | iput(ip); |
| 50 | u.u_error = ENOTDIR; |
| 51 | return; |
| 52 | } |
| 53 | fs = mountfs(dev, uap->ronly, ip); |
| 54 | if (fs == 0) |
| 55 | return; |
| 56 | (void) copyinstr(uap->freg, fs->fs_fsmnt, sizeof(fs->fs_fsmnt)-1, &len); |
| 57 | bzero(fs->fs_fsmnt + len, sizeof (fs->fs_fsmnt) - len); |
| 58 | } |
| 59 | |
| 60 | /* this routine has races if running twice */ |
| 61 | struct fs * |
| 62 | mountfs(dev, ronly, ip) |
| 63 | dev_t dev; |
| 64 | int ronly; |
| 65 | struct inode *ip; |
| 66 | { |
| 67 | register struct mount *mp = 0; |
| 68 | struct buf *tp = 0; |
| 69 | register struct buf *bp = 0; |
| 70 | register struct fs *fs; |
| 71 | int blks; |
| 72 | caddr_t space; |
| 73 | int i, size; |
| 74 | register error; |
| 75 | int needclose = 0; |
| 76 | |
| 77 | error = |
| 78 | (*bdevsw[major(dev)].d_open)(dev, ronly ? FREAD : FREAD|FWRITE); |
| 79 | if (error) |
| 80 | goto out; |
| 81 | needclose = 1; |
| 82 | tp = bread(dev, SBLOCK, SBSIZE); |
| 83 | if (tp->b_flags & B_ERROR) |
| 84 | goto out; |
| 85 | for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++) |
| 86 | if (mp->m_bufp != 0 && dev == mp->m_dev) { |
| 87 | mp = 0; |
| 88 | error = EBUSY; |
| 89 | needclose = 0; |
| 90 | goto out; |
| 91 | } |
| 92 | for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++) |
| 93 | if (mp->m_bufp == 0) |
| 94 | goto found; |
| 95 | mp = 0; |
| 96 | error = EMFILE; /* needs translation */ |
| 97 | goto out; |
| 98 | found: |
| 99 | mp->m_bufp = tp; /* just to reserve this slot */ |
| 100 | mp->m_dev = NODEV; |
| 101 | fs = tp->b_un.b_fs; |
| 102 | if (fs->fs_magic != FS_MAGIC || fs->fs_bsize > MAXBSIZE |
| 103 | || fs->fs_bsize < sizeof(struct fs)) { |
| 104 | error = EINVAL; /* also needs translation */ |
| 105 | goto out; |
| 106 | } |
| 107 | bp = geteblk((int)fs->fs_sbsize); |
| 108 | mp->m_bufp = bp; |
| 109 | bcopy((caddr_t)tp->b_un.b_addr, (caddr_t)bp->b_un.b_addr, |
| 110 | (u_int)fs->fs_sbsize); |
| 111 | brelse(tp); |
| 112 | tp = 0; |
| 113 | fs = bp->b_un.b_fs; |
| 114 | fs->fs_ronly = (ronly != 0); |
| 115 | if (ronly == 0) |
| 116 | fs->fs_fmod = 1; |
| 117 | blks = howmany(fs->fs_cssize, fs->fs_fsize); |
| 118 | space = wmemall(vmemall, (int)fs->fs_cssize); |
| 119 | if (space == 0) { |
| 120 | error = ENOMEM; |
| 121 | goto out; |
| 122 | } |
| 123 | for (i = 0; i < blks; i += fs->fs_frag) { |
| 124 | size = fs->fs_bsize; |
| 125 | if (i + fs->fs_frag > blks) |
| 126 | size = (blks - i) * fs->fs_fsize; |
| 127 | tp = bread(dev, fsbtodb(fs, fs->fs_csaddr + i), size); |
| 128 | if (tp->b_flags&B_ERROR) { |
| 129 | wmemfree(space, (int)fs->fs_cssize); |
| 130 | goto out; |
| 131 | } |
| 132 | bcopy((caddr_t)tp->b_un.b_addr, space, (u_int)size); |
| 133 | fs->fs_csp[fragstoblks(fs, i)] = (struct csum *)space; |
| 134 | space += size; |
| 135 | brelse(tp); |
| 136 | tp = 0; |
| 137 | } |
| 138 | mp->m_inodp = ip; |
| 139 | mp->m_dev = dev; |
| 140 | if (ip) { |
| 141 | ip->i_flag |= IMOUNT; |
| 142 | iunlock(ip); |
| 143 | } |
| 144 | return (fs); |
| 145 | out: |
| 146 | if (error == 0) |
| 147 | error = EIO; |
| 148 | if (ip) |
| 149 | iput(ip); |
| 150 | if (mp) |
| 151 | mp->m_bufp = 0; |
| 152 | if (bp) |
| 153 | brelse(bp); |
| 154 | if (tp) |
| 155 | brelse(tp); |
| 156 | if (needclose) { |
| 157 | (*bdevsw[major(dev)].d_close)(dev, ronly? FREAD : FREAD|FWRITE); |
| 158 | binval(dev); |
| 159 | } |
| 160 | u.u_error = error; |
| 161 | return (0); |
| 162 | } |
| 163 | |
| 164 | umount() |
| 165 | { |
| 166 | struct a { |
| 167 | char *fspec; |
| 168 | } *uap = (struct a *)u.u_ap; |
| 169 | |
| 170 | u.u_error = unmount1(uap->fspec, 0); |
| 171 | } |
| 172 | |
| 173 | unmount1(fname, forcibly) |
| 174 | caddr_t fname; |
| 175 | int forcibly; |
| 176 | { |
| 177 | dev_t dev; |
| 178 | register struct mount *mp; |
| 179 | int stillopen, flag, error; |
| 180 | register struct inode *ip; |
| 181 | register struct fs *fs; |
| 182 | |
| 183 | error = getmdev(&dev, fname); |
| 184 | if (error) |
| 185 | return (error); |
| 186 | for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++) |
| 187 | if (mp->m_bufp != NULL && dev == mp->m_dev) |
| 188 | goto found; |
| 189 | return (EINVAL); |
| 190 | found: |
| 191 | xumount(dev); /* remove unused sticky files from text table */ |
| 192 | nchinval(dev); /* flush the name cache */ |
| 193 | update(); |
| 194 | #ifdef QUOTA |
| 195 | if ((stillopen = iflush(dev, mp->m_qinod)) < 0 && !forcibly) |
| 196 | #else |
| 197 | if ((stillopen = iflush(dev)) < 0 && !forcibly) |
| 198 | #endif |
| 199 | return (EBUSY); |
| 200 | if (stillopen < 0) |
| 201 | return (EBUSY); /* XXX */ |
| 202 | #ifdef QUOTA |
| 203 | closedq(mp); |
| 204 | /* |
| 205 | * Here we have to iflush again to get rid of the quota inode. |
| 206 | * A drag, but it would be ugly to cheat, & this doesn't happen often |
| 207 | */ |
| 208 | (void)iflush(dev, (struct inode *)NULL); |
| 209 | #endif |
| 210 | ip = mp->m_inodp; |
| 211 | ip->i_flag &= ~IMOUNT; |
| 212 | irele(ip); |
| 213 | fs = mp->m_bufp->b_un.b_fs; |
| 214 | wmemfree((caddr_t)fs->fs_csp[0], (int)fs->fs_cssize); |
| 215 | flag = !fs->fs_ronly; |
| 216 | brelse(mp->m_bufp); |
| 217 | mp->m_bufp = 0; |
| 218 | mp->m_dev = 0; |
| 219 | mpurge(mp - &mount[0]); |
| 220 | if (!stillopen) { |
| 221 | (*bdevsw[major(dev)].d_close)(dev, flag); |
| 222 | binval(dev); |
| 223 | } |
| 224 | return (0); |
| 225 | } |
| 226 | |
| 227 | sbupdate(mp) |
| 228 | struct mount *mp; |
| 229 | { |
| 230 | register struct fs *fs = mp->m_bufp->b_un.b_fs; |
| 231 | register struct buf *bp; |
| 232 | int blks; |
| 233 | caddr_t space; |
| 234 | int i, size; |
| 235 | |
| 236 | bp = getblk(mp->m_dev, SBLOCK, (int)fs->fs_sbsize); |
| 237 | bcopy((caddr_t)fs, bp->b_un.b_addr, (u_int)fs->fs_sbsize); |
| 238 | bwrite(bp); |
| 239 | blks = howmany(fs->fs_cssize, fs->fs_fsize); |
| 240 | space = (caddr_t)fs->fs_csp[0]; |
| 241 | for (i = 0; i < blks; i += fs->fs_frag) { |
| 242 | size = fs->fs_bsize; |
| 243 | if (i + fs->fs_frag > blks) |
| 244 | size = (blks - i) * fs->fs_fsize; |
| 245 | bp = getblk(mp->m_dev, fsbtodb(fs, fs->fs_csaddr + i), size); |
| 246 | bcopy(space, bp->b_un.b_addr, (u_int)size); |
| 247 | space += size; |
| 248 | bwrite(bp); |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | /* |
| 253 | * Common code for mount and umount. |
| 254 | * Check that the user's argument is a reasonable |
| 255 | * thing on which to mount, and return the device number if so. |
| 256 | */ |
| 257 | getmdev(pdev, fname) |
| 258 | caddr_t fname; |
| 259 | dev_t *pdev; |
| 260 | { |
| 261 | dev_t dev; |
| 262 | register struct inode *ip; |
| 263 | register struct nameidata *ndp = &u.u_nd; |
| 264 | |
| 265 | if (!suser()) |
| 266 | return (u.u_error); |
| 267 | ndp->ni_nameiop = LOOKUP | FOLLOW; |
| 268 | ndp->ni_segflg = UIO_USERSPACE; |
| 269 | ndp->ni_dirp = fname; |
| 270 | ip = namei(ndp); |
| 271 | if (ip == NULL) { |
| 272 | if (u.u_error == ENOENT) |
| 273 | return (ENODEV); /* needs translation */ |
| 274 | return (u.u_error); |
| 275 | } |
| 276 | if ((ip->i_mode&IFMT) != IFBLK) { |
| 277 | iput(ip); |
| 278 | return (ENOTBLK); |
| 279 | } |
| 280 | dev = (dev_t)ip->i_rdev; |
| 281 | iput(ip); |
| 282 | if (major(dev) >= nblkdev) |
| 283 | return (ENXIO); |
| 284 | *pdev = dev; |
| 285 | return (0); |
| 286 | } |