111a9947fSrtm #include "types.h" 21f544842Skaashoek #include "stat.h" 311a9947fSrtm #include "param.h" 411a9947fSrtm #include "x86.h" 511a9947fSrtm #include "mmu.h" 611a9947fSrtm #include "proc.h" 711a9947fSrtm #include "defs.h" 811a9947fSrtm #include "spinlock.h" 911a9947fSrtm #include "buf.h" 1011a9947fSrtm #include "fs.h" 1111a9947fSrtm #include "fsvar.h" 126fa5ffb5Skaashoek #include "dev.h" 1311a9947fSrtm 1411a9947fSrtm // these are inodes currently in use 1511a9947fSrtm // an entry is free if count == 0 1611a9947fSrtm struct inode inode[NINODE]; 175be0039cSrtm struct spinlock inode_table_lock; 1811a9947fSrtm 199d3fb671Srtm uint rootdev = 1; 209d3fb671Srtm 215be0039cSrtm void 225be0039cSrtm iinit(void) 235be0039cSrtm { 245be0039cSrtm initlock(&inode_table_lock, "inode_table"); 255be0039cSrtm } 265be0039cSrtm 2724111398Skaashoek static uint 2824111398Skaashoek balloc(uint dev) 2924111398Skaashoek { 3024111398Skaashoek int b; 3124111398Skaashoek struct buf *bp; 3224111398Skaashoek struct superblock *sb; 3328d9ef04Skaashoek int bi = 0; 3424111398Skaashoek int size; 3524111398Skaashoek int ninodes; 3624111398Skaashoek uchar m; 3724111398Skaashoek 3824111398Skaashoek bp = bread(dev, 1); 3924111398Skaashoek sb = (struct superblock *) bp->data; 4024111398Skaashoek size = sb->size; 4124111398Skaashoek ninodes = sb->ninodes; 4224111398Skaashoek 4324111398Skaashoek for (b = 0; b < size; b++) { 4424111398Skaashoek if (b % BPB == 0) { 4524111398Skaashoek brelse(bp); 4624111398Skaashoek bp = bread(dev, BBLOCK(b, ninodes)); 4724111398Skaashoek } 4824111398Skaashoek bi = b % BPB; 4924111398Skaashoek m = 0x1 << (bi % 8); 5024111398Skaashoek if ((bp->data[bi/8] & m) == 0) { // is block free? 5124111398Skaashoek break; 5224111398Skaashoek } 5324111398Skaashoek } 5424111398Skaashoek if (b >= size) 5524111398Skaashoek panic("balloc: out of blocks\n"); 5624111398Skaashoek 5724111398Skaashoek bp->data[bi/8] |= 0x1 << (bi % 8); 5805e97551Srtm bwrite (bp, BBLOCK(b, ninodes)); // mark it allocated on disk 5928d9ef04Skaashoek brelse(bp); 6024111398Skaashoek return b; 6124111398Skaashoek } 6224111398Skaashoek 6328d9ef04Skaashoek static void 6428d9ef04Skaashoek bfree(int dev, uint b) 6528d9ef04Skaashoek { 6628d9ef04Skaashoek struct buf *bp; 6728d9ef04Skaashoek struct superblock *sb; 6828d9ef04Skaashoek int bi; 6928d9ef04Skaashoek int ninodes; 7028d9ef04Skaashoek uchar m; 7128d9ef04Skaashoek 7228d9ef04Skaashoek bp = bread(dev, 1); 7328d9ef04Skaashoek sb = (struct superblock *) bp->data; 7428d9ef04Skaashoek ninodes = sb->ninodes; 7528d9ef04Skaashoek brelse(bp); 7628d9ef04Skaashoek 77c372e8dcSkaashoek bp = bread(dev, b); 78c372e8dcSkaashoek memset(bp->data, 0, BSIZE); 79c372e8dcSkaashoek bwrite(bp, b); 80c372e8dcSkaashoek brelse(bp); 81c372e8dcSkaashoek 8228d9ef04Skaashoek bp = bread(dev, BBLOCK(b, ninodes)); 8328d9ef04Skaashoek bi = b % BPB; 8428d9ef04Skaashoek m = ~(0x1 << (bi %8)); 8528d9ef04Skaashoek bp->data[bi/8] &= m; 8605e97551Srtm bwrite (bp, BBLOCK(b, ninodes)); // mark it free on disk 8728d9ef04Skaashoek brelse(bp); 8828d9ef04Skaashoek } 8924111398Skaashoek 909d3fb671Srtm // returns an inode with busy set and incremented reference count. 9111a9947fSrtm struct inode * 9211a9947fSrtm iget(uint dev, uint inum) 9311a9947fSrtm { 9417e3cf15Srtm struct inode *ip, *nip; 9511a9947fSrtm struct dinode *dip; 9611a9947fSrtm struct buf *bp; 9711a9947fSrtm 9811a9947fSrtm acquire(&inode_table_lock); 9911a9947fSrtm 10011a9947fSrtm loop: 10117e3cf15Srtm nip = 0; 10211a9947fSrtm for(ip = &inode[0]; ip < &inode[NINODE]; ip++){ 10311a9947fSrtm if(ip->count > 0 && ip->dev == dev && ip->inum == inum){ 10411a9947fSrtm if(ip->busy){ 10511a9947fSrtm sleep(ip, &inode_table_lock); 10611a9947fSrtm goto loop; 10711a9947fSrtm } 10811a9947fSrtm ip->count++; 10917a85657Srtm ip->busy = 1; 11011a9947fSrtm release(&inode_table_lock); 11111a9947fSrtm return ip; 11211a9947fSrtm } 11311a9947fSrtm if(nip == 0 && ip->count == 0) 11411a9947fSrtm nip = ip; 11511a9947fSrtm } 11611a9947fSrtm 11711a9947fSrtm if(nip == 0) 11811a9947fSrtm panic("out of inodes"); 11911a9947fSrtm 12011a9947fSrtm nip->dev = dev; 12111a9947fSrtm nip->inum = inum; 12211a9947fSrtm nip->count = 1; 12311a9947fSrtm nip->busy = 1; 12411a9947fSrtm 12511a9947fSrtm release(&inode_table_lock); 12611a9947fSrtm 12724111398Skaashoek bp = bread(dev, IBLOCK(inum)); 12811a9947fSrtm dip = &((struct dinode *)(bp->data))[inum % IPB]; 12911a9947fSrtm nip->type = dip->type; 130e8d11c2eSkaashoek nip->major = dip->major; 131e8d11c2eSkaashoek nip->minor = dip->minor; 13211a9947fSrtm nip->nlink = dip->nlink; 13311a9947fSrtm nip->size = dip->size; 13411a9947fSrtm memmove(nip->addrs, dip->addrs, sizeof(nip->addrs)); 13511a9947fSrtm brelse(bp); 13611a9947fSrtm 13711a9947fSrtm return nip; 13811a9947fSrtm } 13911a9947fSrtm 14028d9ef04Skaashoek void 14128d9ef04Skaashoek iupdate (struct inode *ip) 14228d9ef04Skaashoek { 14328d9ef04Skaashoek struct buf *bp; 14428d9ef04Skaashoek struct dinode *dip; 14528d9ef04Skaashoek 14628d9ef04Skaashoek bp = bread(ip->dev, IBLOCK(ip->inum)); 14728d9ef04Skaashoek dip = &((struct dinode *)(bp->data))[ip->inum % IPB]; 14828d9ef04Skaashoek dip->type = ip->type; 14928d9ef04Skaashoek dip->major = ip->major; 15028d9ef04Skaashoek dip->minor = ip->minor; 15128d9ef04Skaashoek dip->nlink = ip->nlink; 15228d9ef04Skaashoek dip->size = ip->size; 15328d9ef04Skaashoek memmove(dip->addrs, ip->addrs, sizeof(ip->addrs)); 15405e97551Srtm bwrite (bp, IBLOCK(ip->inum)); // mark it allocated on the disk 15528d9ef04Skaashoek brelse(bp); 15628d9ef04Skaashoek } 15728d9ef04Skaashoek 158e8d11c2eSkaashoek struct inode * 159e8d11c2eSkaashoek ialloc(uint dev, short type) 160e8d11c2eSkaashoek { 161e8d11c2eSkaashoek struct inode *ip; 162e8d11c2eSkaashoek struct dinode *dip = 0; 163e8d11c2eSkaashoek struct superblock *sb; 164e8d11c2eSkaashoek int ninodes; 165e8d11c2eSkaashoek int inum; 166e8d11c2eSkaashoek struct buf *bp; 167e8d11c2eSkaashoek 168e8d11c2eSkaashoek bp = bread(dev, 1); 16924111398Skaashoek sb = (struct superblock *) bp->data; 170e8d11c2eSkaashoek ninodes = sb->ninodes; 171e8d11c2eSkaashoek brelse(bp); 172e8d11c2eSkaashoek 173e8d11c2eSkaashoek for (inum = 1; inum < ninodes; inum++) { // loop over inode blocks 17424111398Skaashoek bp = bread(dev, IBLOCK(inum)); 175e8d11c2eSkaashoek dip = &((struct dinode *)(bp->data))[inum % IPB]; 176e8d11c2eSkaashoek if (dip->type == 0) { // a free inode 177e8d11c2eSkaashoek break; 178e8d11c2eSkaashoek } 179e8d11c2eSkaashoek brelse(bp); 180e8d11c2eSkaashoek } 181e8d11c2eSkaashoek 18217e3cf15Srtm if (inum >= ninodes) 18324111398Skaashoek panic ("ialloc: no inodes left\n"); 184e8d11c2eSkaashoek 185e8d11c2eSkaashoek dip->type = type; 18605e97551Srtm bwrite (bp, IBLOCK(inum)); // mark it allocated on the disk 187e8d11c2eSkaashoek brelse(bp); 188e8d11c2eSkaashoek ip = iget (dev, inum); 189e8d11c2eSkaashoek return ip; 190e8d11c2eSkaashoek } 191e8d11c2eSkaashoek 19228d9ef04Skaashoek static void 19324437cd5Skaashoek ifree(struct inode *ip) 194e8d11c2eSkaashoek { 19528d9ef04Skaashoek ip->type = 0; 19628d9ef04Skaashoek iupdate(ip); 197e8d11c2eSkaashoek } 198e8d11c2eSkaashoek 19911a9947fSrtm void 2009d3fb671Srtm ilock(struct inode *ip) 2019d3fb671Srtm { 2029d3fb671Srtm if(ip->count < 1) 2039d3fb671Srtm panic("ilock"); 2049d3fb671Srtm 2059d3fb671Srtm acquire(&inode_table_lock); 2069d3fb671Srtm 2079d3fb671Srtm while(ip->busy) 2089d3fb671Srtm sleep(ip, &inode_table_lock); 2099d3fb671Srtm ip->busy = 1; 2109d3fb671Srtm 2119d3fb671Srtm release(&inode_table_lock); 2129d3fb671Srtm } 2139d3fb671Srtm 2149d3fb671Srtm // caller is holding onto a reference to this inode, but no 2159d3fb671Srtm // longer needs to examine or change it, so clear ip->busy. 2169d3fb671Srtm void 2179d3fb671Srtm iunlock(struct inode *ip) 2189d3fb671Srtm { 21917e3cf15Srtm if(ip->busy != 1 || ip->count < 1) 2209d3fb671Srtm panic("iunlock"); 2219d3fb671Srtm 2229d3fb671Srtm acquire(&inode_table_lock); 2239d3fb671Srtm 2249d3fb671Srtm ip->busy = 0; 2259d3fb671Srtm wakeup(ip); 2269d3fb671Srtm 2279d3fb671Srtm release(&inode_table_lock); 2289d3fb671Srtm } 2299d3fb671Srtm 23022bac2cbSkaashoek uint 23122bac2cbSkaashoek bmap(struct inode *ip, uint bn) 23222bac2cbSkaashoek { 23322bac2cbSkaashoek unsigned x; 234ea2909b6Skaashoek uint *a; 235ea2909b6Skaashoek struct buf *inbp; 23622bac2cbSkaashoek 237ea2909b6Skaashoek if(bn >= MAXFILE) 23822bac2cbSkaashoek panic("bmap 1"); 239ea2909b6Skaashoek if (bn < NDIRECT) { 24022bac2cbSkaashoek x = ip->addrs[bn]; 24122bac2cbSkaashoek if (x == 0) 24222bac2cbSkaashoek panic("bmap 2"); 243ea2909b6Skaashoek } else { 244*5051da6dSrtm if(ip->addrs[INDIRECT] == 0) 245*5051da6dSrtm panic("bmap 3"); 2461be76685Skaashoek inbp = bread(ip->dev, ip->addrs[INDIRECT]); 247ea2909b6Skaashoek a = (uint *) inbp->data; 248ea2909b6Skaashoek x = a[bn - NDIRECT]; 249ea2909b6Skaashoek brelse(inbp); 250ea2909b6Skaashoek if (x == 0) 251*5051da6dSrtm panic("bmap 4"); 252ea2909b6Skaashoek } 25322bac2cbSkaashoek return x; 25422bac2cbSkaashoek } 25522bac2cbSkaashoek 25622bac2cbSkaashoek void 25722bac2cbSkaashoek iunlink(struct inode *ip) 25822bac2cbSkaashoek { 259ea2909b6Skaashoek int i, j; 2601be76685Skaashoek struct buf *inbp; 26122bac2cbSkaashoek 26222bac2cbSkaashoek // free inode, its blocks, and remove dir entry 263ea2909b6Skaashoek for (i = 0; i < NADDRS; i++) { 26422bac2cbSkaashoek if (ip->addrs[i] != 0) { 265ea2909b6Skaashoek if (i == INDIRECT) { 2661be76685Skaashoek inbp = bread(ip->dev, ip->addrs[INDIRECT]); 2671be76685Skaashoek uint *a = (uint *) inbp->data; 268bcfb84b6Srtm for (j = 0; j < NINDIRECT; j++) { 269ea2909b6Skaashoek if (a[j] != 0) { 270ea2909b6Skaashoek bfree(ip->dev, a[j]); 271ea2909b6Skaashoek a[j] = 0; 272ea2909b6Skaashoek } 273ea2909b6Skaashoek } 2741be76685Skaashoek brelse(inbp); 275ea2909b6Skaashoek } 27622bac2cbSkaashoek bfree(ip->dev, ip->addrs[i]); 27722bac2cbSkaashoek ip->addrs[i] = 0; 27822bac2cbSkaashoek } 27922bac2cbSkaashoek } 28022bac2cbSkaashoek ip->size = 0; 28122bac2cbSkaashoek ip->major = 0; 28222bac2cbSkaashoek ip->minor = 0; 28322bac2cbSkaashoek iupdate(ip); 28422bac2cbSkaashoek ifree(ip); // is this the right order? 28522bac2cbSkaashoek } 28622bac2cbSkaashoek 2879d3fb671Srtm // caller is releasing a reference to this inode. 2889d3fb671Srtm // you must have the inode lock. 2899d3fb671Srtm void 29011a9947fSrtm iput(struct inode *ip) 29111a9947fSrtm { 2929d3fb671Srtm if(ip->count < 1 || ip->busy != 1) 2939d3fb671Srtm panic("iput"); 2949d3fb671Srtm 29517e3cf15Srtm if ((ip->count == 1) && (ip->nlink == 0)) 29622bac2cbSkaashoek iunlink(ip); 29722bac2cbSkaashoek 29811a9947fSrtm acquire(&inode_table_lock); 29911a9947fSrtm 30011a9947fSrtm ip->count -= 1; 30111a9947fSrtm ip->busy = 0; 30211a9947fSrtm wakeup(ip); 30311a9947fSrtm 30411a9947fSrtm release(&inode_table_lock); 30511a9947fSrtm } 3069d3fb671Srtm 3079d3fb671Srtm void 30832630628Srtm idecref(struct inode *ip) 3099d3fb671Srtm { 310211ff0c6Srtm ilock(ip); 311211ff0c6Srtm iput(ip); 3129d3fb671Srtm } 3139d3fb671Srtm 3141f544842Skaashoek void 315e958c538Skaashoek iincref(struct inode *ip) 316e958c538Skaashoek { 317e958c538Skaashoek ilock(ip); 318e958c538Skaashoek ip->count++; 319e958c538Skaashoek iunlock(ip); 320e958c538Skaashoek } 321e958c538Skaashoek 322e958c538Skaashoek void 3231f544842Skaashoek stati(struct inode *ip, struct stat *st) 3241f544842Skaashoek { 3251f544842Skaashoek st->st_dev = ip->dev; 3261f544842Skaashoek st->st_ino = ip->inum; 3271f544842Skaashoek st->st_type = ip->type; 3281f544842Skaashoek st->st_nlink = ip->nlink; 3291f544842Skaashoek st->st_size = ip->size; 3301f544842Skaashoek } 3311f544842Skaashoek 33222bac2cbSkaashoek #define min(a, b) ((a) < (b) ? (a) : (b)) 33322bac2cbSkaashoek 334c59361f1Srtm int 33517a85657Srtm readi(struct inode *ip, char *dst, uint off, uint n) 336c59361f1Srtm { 337c59361f1Srtm uint target = n, n1; 338c59361f1Srtm struct buf *bp; 339c59361f1Srtm 340939f9edeSkaashoek if (ip->type == T_DEV) { 341939f9edeSkaashoek if (ip->major < 0 || ip->major >= NDEV || !devsw[ip->major].d_read) 342939f9edeSkaashoek return -1; 34317a85657Srtm return devsw[ip->major].d_read (ip->minor, dst, n); 344939f9edeSkaashoek } 345939f9edeSkaashoek 346c59361f1Srtm while(n > 0 && off < ip->size){ 34724111398Skaashoek bp = bread(ip->dev, bmap(ip, off / BSIZE)); 348c59361f1Srtm n1 = min(n, ip->size - off); 34924111398Skaashoek n1 = min(n1, BSIZE - (off % BSIZE)); 35024111398Skaashoek memmove(dst, bp->data + (off % BSIZE), n1); 351c59361f1Srtm n -= n1; 352c59361f1Srtm off += n1; 353c59361f1Srtm dst += n1; 354c59361f1Srtm brelse(bp); 355c59361f1Srtm } 356c59361f1Srtm 357c59361f1Srtm return target - n; 358c59361f1Srtm } 359c59361f1Srtm 3601be76685Skaashoek static int 361ea2909b6Skaashoek newblock(struct inode *ip, uint lbn) 362ea2909b6Skaashoek { 363ea2909b6Skaashoek struct buf *inbp; 364ea2909b6Skaashoek uint *inaddrs; 365ea2909b6Skaashoek uint b; 366ea2909b6Skaashoek 367ea2909b6Skaashoek if (lbn < NDIRECT) { 368ea2909b6Skaashoek if (ip->addrs[lbn] == 0) { 369ea2909b6Skaashoek b = balloc(ip->dev); 370ea2909b6Skaashoek if (b <= 0) return -1; 371ea2909b6Skaashoek ip->addrs[lbn] = b; 372ea2909b6Skaashoek } 373ea2909b6Skaashoek } else { 374ea2909b6Skaashoek if (ip->addrs[INDIRECT] == 0) { 375ea2909b6Skaashoek b = balloc(ip->dev); 376ea2909b6Skaashoek if (b <= 0) return -1; 377ea2909b6Skaashoek ip->addrs[INDIRECT] = b; 378ea2909b6Skaashoek } 3791be76685Skaashoek inbp = bread(ip->dev, ip->addrs[INDIRECT]); 380ea2909b6Skaashoek inaddrs = (uint *) inbp->data; 381ea2909b6Skaashoek if (inaddrs[lbn - NDIRECT] == 0) { 382ea2909b6Skaashoek b = balloc(ip->dev); 383ea2909b6Skaashoek if (b <= 0) return -1; 384ea2909b6Skaashoek inaddrs[lbn - NDIRECT] = b; 3851be76685Skaashoek bwrite(inbp, ip->addrs[INDIRECT]); 386ea2909b6Skaashoek } 387ea2909b6Skaashoek brelse(inbp); 388ea2909b6Skaashoek } 389ea2909b6Skaashoek return 0; 390ea2909b6Skaashoek } 391ea2909b6Skaashoek 392ea2909b6Skaashoek int 39317a85657Srtm writei(struct inode *ip, char *addr, uint off, uint n) 3946fa5ffb5Skaashoek { 3956fa5ffb5Skaashoek if (ip->type == T_DEV) { 396939f9edeSkaashoek if (ip->major < 0 || ip->major >= NDEV || !devsw[ip->major].d_write) 397939f9edeSkaashoek return -1; 3986fa5ffb5Skaashoek return devsw[ip->major].d_write (ip->minor, addr, n); 399ea2909b6Skaashoek } else if (ip->type == T_FILE || ip->type == T_DIR) { 40028d9ef04Skaashoek struct buf *bp; 40128d9ef04Skaashoek int r = 0; 40228d9ef04Skaashoek int m; 40328d9ef04Skaashoek int lbn; 40428d9ef04Skaashoek while (r < n) { 40528d9ef04Skaashoek lbn = off / BSIZE; 406ea2909b6Skaashoek if (lbn >= MAXFILE) return r; 407ea2909b6Skaashoek if (newblock(ip, lbn) < 0) { 408ea2909b6Skaashoek cprintf("newblock failed\n"); 409ea2909b6Skaashoek return r; 41028d9ef04Skaashoek } 41122bac2cbSkaashoek m = min(BSIZE - off % BSIZE, n-r); 412ea2909b6Skaashoek bp = bread(ip->dev, bmap(ip, lbn)); 41328d9ef04Skaashoek memmove (bp->data + off % BSIZE, addr, m); 414ea2909b6Skaashoek bwrite (bp, bmap(ip, lbn)); 41528d9ef04Skaashoek brelse (bp); 41628d9ef04Skaashoek r += m; 41728d9ef04Skaashoek off += m; 41828d9ef04Skaashoek } 41928d9ef04Skaashoek if (r > 0) { 42028d9ef04Skaashoek if (off > ip->size) { 421bdb66433Skaashoek if (ip->type == T_DIR) ip->size = ((off / BSIZE) + 1) * BSIZE; 422bdb66433Skaashoek else ip->size = off; 42328d9ef04Skaashoek } 42428d9ef04Skaashoek iupdate(ip); 42528d9ef04Skaashoek } 42628d9ef04Skaashoek return r; 4276fa5ffb5Skaashoek } else { 4286fa5ffb5Skaashoek panic ("writei: unknown type\n"); 4298a8be1b8Srtm return 0; 4306fa5ffb5Skaashoek } 4316fa5ffb5Skaashoek } 4326fa5ffb5Skaashoek 433211ff0c6Srtm // look up a path name, in one of three modes. 434211ff0c6Srtm // NAMEI_LOOKUP: return locked target inode. 435211ff0c6Srtm // NAMEI_CREATE: return locked parent inode. 436*5051da6dSrtm // return 0 if name does exist. 437*5051da6dSrtm // *ret_last points to last path component (i.e. new file name). 438*5051da6dSrtm // *ret_ip points to the the name that did exist, if it did. 439*5051da6dSrtm // *ret_ip and *ret_last may be zero even if return value is zero. 440211ff0c6Srtm // NAMEI_DELETE: return locked parent inode, offset of dirent in *ret_off. 441211ff0c6Srtm // return 0 if name doesn't exist. 4429d3fb671Srtm struct inode * 443*5051da6dSrtm namei(char *path, int mode, uint *ret_off, char **ret_last, struct inode **ret_ip) 4449d3fb671Srtm { 4459d3fb671Srtm struct inode *dp; 4468787cd01Skaashoek struct proc *p = curproc[cpu()]; 447211ff0c6Srtm char *cp = path, *cp1; 4489d3fb671Srtm uint off, dev; 4499d3fb671Srtm struct buf *bp; 4509d3fb671Srtm struct dirent *ep; 451211ff0c6Srtm int i, atend; 4529d3fb671Srtm unsigned ninum; 4539d3fb671Srtm 454*5051da6dSrtm if(mode == NAMEI_DELETE && ret_off == 0) 455*5051da6dSrtm panic("namei no ret_off"); 456*5051da6dSrtm if(mode == NAMEI_CREATE && ret_last == 0) 457*5051da6dSrtm panic("namei no ret_last"); 458*5051da6dSrtm if(ret_off) 459*5051da6dSrtm *ret_off = 0xffffffff; 460*5051da6dSrtm if(ret_last) 461*5051da6dSrtm *ret_last = 0; 462*5051da6dSrtm if(ret_ip) 463*5051da6dSrtm *ret_ip = 0; 464*5051da6dSrtm 4658787cd01Skaashoek if (*cp == '/') dp = iget(rootdev, 1); 4668787cd01Skaashoek else { 4678787cd01Skaashoek dp = p->cwd; 4688787cd01Skaashoek iincref(dp); 4698787cd01Skaashoek ilock(dp); 4708787cd01Skaashoek } 4719d3fb671Srtm 4729d3fb671Srtm while(*cp == '/') 4739d3fb671Srtm cp++; 4749d3fb671Srtm 4759d3fb671Srtm while(1){ 4760633b971Skaashoek if(*cp == '\0'){ 477211ff0c6Srtm if(mode == NAMEI_LOOKUP) 4789d3fb671Srtm return dp; 479*5051da6dSrtm if(mode == NAMEI_CREATE && ret_ip){ 480*5051da6dSrtm *ret_ip = dp; 481*5051da6dSrtm return 0; 482*5051da6dSrtm } 483211ff0c6Srtm iput(dp); 484211ff0c6Srtm return 0; 4850633b971Skaashoek } 4869d3fb671Srtm 4879d3fb671Srtm if(dp->type != T_DIR){ 4889d3fb671Srtm iput(dp); 4899d3fb671Srtm return 0; 4909d3fb671Srtm } 4919d3fb671Srtm 49224111398Skaashoek for(off = 0; off < dp->size; off += BSIZE){ 49324111398Skaashoek bp = bread(dp->dev, bmap(dp, off / BSIZE)); 4949d3fb671Srtm for(ep = (struct dirent *) bp->data; 49524111398Skaashoek ep < (struct dirent *) (bp->data + BSIZE); 4969d3fb671Srtm ep++){ 4979d3fb671Srtm if(ep->inum == 0) 4989d3fb671Srtm continue; 4999d3fb671Srtm for(i = 0; i < DIRSIZ && cp[i] != '/' && cp[i]; i++) 5009d3fb671Srtm if(cp[i] != ep->name[i]) 5019d3fb671Srtm break; 5029d3fb671Srtm if((cp[i] == '\0' || cp[i] == '/') && (i >= DIRSIZ || ep->name[i] == '\0')){ 503211ff0c6Srtm off += (uchar*)ep - bp->data; 5049d3fb671Srtm ninum = ep->inum; 5059d3fb671Srtm brelse(bp); 5069d3fb671Srtm cp += i; 5079d3fb671Srtm goto found; 5089d3fb671Srtm } 5099d3fb671Srtm } 5109d3fb671Srtm brelse(bp); 5119d3fb671Srtm } 512211ff0c6Srtm atend = 1; 513211ff0c6Srtm for(cp1 = cp; *cp1; cp1++) 514211ff0c6Srtm if(*cp1 == '/') 515211ff0c6Srtm atend = 0; 516*5051da6dSrtm if(mode == NAMEI_CREATE && atend){ 517*5051da6dSrtm if(*cp == '\0'){ 518*5051da6dSrtm iput(dp); 519*5051da6dSrtm return 0; 520*5051da6dSrtm } 521*5051da6dSrtm *ret_last = cp; 522211ff0c6Srtm return dp; 523*5051da6dSrtm } 524211ff0c6Srtm 5259d3fb671Srtm iput(dp); 5269d3fb671Srtm return 0; 5279d3fb671Srtm 5289d3fb671Srtm found: 529211ff0c6Srtm if(mode == NAMEI_DELETE && *cp == '\0'){ 530211ff0c6Srtm *ret_off = off; 531211ff0c6Srtm return dp; 532211ff0c6Srtm } 5339d3fb671Srtm dev = dp->dev; 5349d3fb671Srtm iput(dp); 5359d3fb671Srtm dp = iget(dev, ninum); 5367ce01cf9Srtm if(dp->type == 0 || dp->nlink < 1) 5377ce01cf9Srtm panic("namei"); 5389d3fb671Srtm while(*cp == '/') 5399d3fb671Srtm cp++; 5409d3fb671Srtm } 5419d3fb671Srtm } 542e8d11c2eSkaashoek 5439e5970d5Srtm void 5449e5970d5Srtm wdir(struct inode *dp, char *name, uint ino) 5459e5970d5Srtm { 5469e5970d5Srtm uint off; 547e4bcd2a3Srtm struct dirent de; 5489e5970d5Srtm int i; 5499e5970d5Srtm 550*5051da6dSrtm if(name[0] == '\0') 551*5051da6dSrtm panic("wdir no name"); 552*5051da6dSrtm 553e4bcd2a3Srtm for(off = 0; off < dp->size; off += sizeof(de)){ 554e4bcd2a3Srtm if(readi(dp, (char *) &de, off, sizeof(de)) != sizeof(de)) 555e4bcd2a3Srtm panic("wdir read"); 556e4bcd2a3Srtm if(de.inum == 0) 557e4bcd2a3Srtm break; 558e4bcd2a3Srtm } 559211ff0c6Srtm 560e4bcd2a3Srtm de.inum = ino; 561*5051da6dSrtm for(i = 0; i < DIRSIZ && name[i]; i++){ 562*5051da6dSrtm if(name[i] == '/') 563*5051da6dSrtm panic("wdir /"); 564e4bcd2a3Srtm de.name[i] = name[i]; 565*5051da6dSrtm } 5669e5970d5Srtm for( ; i < DIRSIZ; i++) 567e4bcd2a3Srtm de.name[i] = '\0'; 568e4bcd2a3Srtm 569e4bcd2a3Srtm if(writei(dp, (char *) &de, off, sizeof(de)) != sizeof(de)) 570e4bcd2a3Srtm panic("wdir write"); 5719e5970d5Srtm } 5729e5970d5Srtm 573e8d11c2eSkaashoek struct inode * 5740633b971Skaashoek mknod(char *cp, short type, short major, short minor) 575e8d11c2eSkaashoek { 5760633b971Skaashoek struct inode *ip, *dp; 577*5051da6dSrtm char *last; 578e8d11c2eSkaashoek 579*5051da6dSrtm if ((dp = namei(cp, NAMEI_CREATE, 0, &last, 0)) == 0) 5800633b971Skaashoek return 0; 581211ff0c6Srtm 582*5051da6dSrtm ip = mknod1(dp, last, type, major, minor); 583*5051da6dSrtm 584*5051da6dSrtm iput(dp); 585*5051da6dSrtm 586*5051da6dSrtm return ip; 587*5051da6dSrtm } 588*5051da6dSrtm 589*5051da6dSrtm struct inode * 590*5051da6dSrtm mknod1(struct inode *dp, char *name, short type, short major, short minor) 591*5051da6dSrtm { 592*5051da6dSrtm struct inode *ip; 593*5051da6dSrtm 594e8d11c2eSkaashoek ip = ialloc(dp->dev, type); 5950633b971Skaashoek if (ip == 0) { 5960633b971Skaashoek iput(dp); 5970633b971Skaashoek return 0; 5980633b971Skaashoek } 599e8d11c2eSkaashoek ip->major = major; 600e8d11c2eSkaashoek ip->minor = minor; 6016c0e444fSkaashoek ip->size = 0; 6027ce01cf9Srtm ip->nlink = 1; 6036c0e444fSkaashoek 6046c0e444fSkaashoek iupdate (ip); // write new inode to disk 605e8d11c2eSkaashoek 606*5051da6dSrtm wdir(dp, name, ip->inum); 607*5051da6dSrtm 608e8d11c2eSkaashoek return ip; 609e8d11c2eSkaashoek } 61024437cd5Skaashoek 61124437cd5Skaashoek int 61224437cd5Skaashoek unlink(char *cp) 61324437cd5Skaashoek { 614211ff0c6Srtm struct inode *ip, *dp; 615211ff0c6Srtm struct dirent de; 61617e3cf15Srtm uint off, inum, dev; 61724437cd5Skaashoek 618*5051da6dSrtm dp = namei(cp, NAMEI_DELETE, &off, 0, 0); 619*5051da6dSrtm if(dp == 0) 62024437cd5Skaashoek return -1; 62124437cd5Skaashoek 62217e3cf15Srtm dev = dp->dev; 62317e3cf15Srtm 62417e3cf15Srtm if(readi(dp, (char*)&de, off, sizeof(de)) != sizeof(de) || de.inum == 0) 625211ff0c6Srtm panic("unlink no entry"); 62617e3cf15Srtm 627211ff0c6Srtm inum = de.inum; 62824437cd5Skaashoek 629211ff0c6Srtm memset(&de, 0, sizeof(de)); 630211ff0c6Srtm if(writei(dp, (char*)&de, off, sizeof(de)) != sizeof(de)) 631211ff0c6Srtm panic("unlink dir write"); 63224437cd5Skaashoek 63324437cd5Skaashoek iupdate(dp); 63424437cd5Skaashoek iput(dp); 635211ff0c6Srtm 63617e3cf15Srtm ip = iget(dev, inum); 637211ff0c6Srtm 638bcfb84b6Srtm if(ip->nlink < 1) 639bcfb84b6Srtm panic("unlink nlink < 1"); 640bcfb84b6Srtm 641211ff0c6Srtm ip->nlink--; 642211ff0c6Srtm 643211ff0c6Srtm iupdate(ip); 64422bac2cbSkaashoek iput(ip); 645211ff0c6Srtm 64624437cd5Skaashoek return 0; 64724437cd5Skaashoek } 6489e5970d5Srtm 6499e5970d5Srtm int 6509e5970d5Srtm link(char *name1, char *name2) 6519e5970d5Srtm { 652211ff0c6Srtm struct inode *ip, *dp; 653*5051da6dSrtm char *last; 6549e5970d5Srtm 655*5051da6dSrtm if ((ip = namei(name1, NAMEI_LOOKUP, 0, 0, 0)) == 0) 6569e5970d5Srtm return -1; 657211ff0c6Srtm if(ip->type == T_DIR){ 658211ff0c6Srtm iput(ip); 659211ff0c6Srtm return -1; 660211ff0c6Srtm } 6619e5970d5Srtm 662211ff0c6Srtm iunlock(ip); 663211ff0c6Srtm 664*5051da6dSrtm if ((dp = namei(name2, NAMEI_CREATE, 0, &last, 0)) == 0) { 665211ff0c6Srtm idecref(ip); 666211ff0c6Srtm return -1; 667211ff0c6Srtm } 668211ff0c6Srtm if(dp->dev != ip->dev){ 669211ff0c6Srtm idecref(ip); 670211ff0c6Srtm iput(dp); 671211ff0c6Srtm return -1; 672211ff0c6Srtm } 673211ff0c6Srtm 674211ff0c6Srtm ilock(ip); 6759e5970d5Srtm ip->nlink += 1; 6769e5970d5Srtm iupdate (ip); 6779e5970d5Srtm 678*5051da6dSrtm wdir(dp, last, ip->inum); 6799e5970d5Srtm iput(dp); 6809e5970d5Srtm iput(ip); 6819e5970d5Srtm 6829e5970d5Srtm return 0; 6839e5970d5Srtm } 684