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 27*f5527388Srsc // Allocate a disk block. 2824111398Skaashoek static uint 2924111398Skaashoek balloc(uint dev) 3024111398Skaashoek { 3124111398Skaashoek int b; 3224111398Skaashoek struct buf *bp; 3324111398Skaashoek struct superblock *sb; 3428d9ef04Skaashoek int bi = 0; 3524111398Skaashoek int size; 3624111398Skaashoek int ninodes; 3724111398Skaashoek uchar m; 3824111398Skaashoek 3924111398Skaashoek bp = bread(dev, 1); 4024111398Skaashoek sb = (struct superblock*) bp->data; 4124111398Skaashoek size = sb->size; 4224111398Skaashoek ninodes = sb->ninodes; 4324111398Skaashoek 4424111398Skaashoek for(b = 0; b < size; b++) { 4524111398Skaashoek if(b % BPB == 0) { 4624111398Skaashoek brelse(bp); 4724111398Skaashoek bp = bread(dev, BBLOCK(b, ninodes)); 4824111398Skaashoek } 4924111398Skaashoek bi = b % BPB; 5024111398Skaashoek m = 0x1 << (bi % 8); 5124111398Skaashoek if((bp->data[bi/8] & m) == 0) { // is block free? 5224111398Skaashoek break; 5324111398Skaashoek } 5424111398Skaashoek } 5524111398Skaashoek if(b >= size) 562aa4c3bcSrtm panic("balloc: out of blocks"); 5724111398Skaashoek 5824111398Skaashoek bp->data[bi/8] |= 0x1 << (bi % 8); 5905e97551Srtm bwrite(bp, BBLOCK(b, ninodes)); // mark it allocated on disk 6028d9ef04Skaashoek brelse(bp); 6124111398Skaashoek return b; 6224111398Skaashoek } 6324111398Skaashoek 6428d9ef04Skaashoek static void 6528d9ef04Skaashoek bfree(int dev, uint b) 6628d9ef04Skaashoek { 6728d9ef04Skaashoek struct buf *bp; 6828d9ef04Skaashoek struct superblock *sb; 6928d9ef04Skaashoek int bi; 7028d9ef04Skaashoek int ninodes; 7128d9ef04Skaashoek uchar m; 7228d9ef04Skaashoek 7328d9ef04Skaashoek bp = bread(dev, 1); 7428d9ef04Skaashoek sb = (struct superblock*) bp->data; 7528d9ef04Skaashoek ninodes = sb->ninodes; 7628d9ef04Skaashoek brelse(bp); 7728d9ef04Skaashoek 78c372e8dcSkaashoek bp = bread(dev, b); 79c372e8dcSkaashoek memset(bp->data, 0, BSIZE); 80c372e8dcSkaashoek bwrite(bp, b); 81c372e8dcSkaashoek brelse(bp); 82c372e8dcSkaashoek 8328d9ef04Skaashoek bp = bread(dev, BBLOCK(b, ninodes)); 8428d9ef04Skaashoek bi = b % BPB; 8528d9ef04Skaashoek m = ~(0x1 << (bi %8)); 8628d9ef04Skaashoek bp->data[bi/8] &= m; 8705e97551Srtm bwrite(bp, BBLOCK(b, ninodes)); // mark it free on disk 8828d9ef04Skaashoek brelse(bp); 8928d9ef04Skaashoek } 9024111398Skaashoek 91*f5527388Srsc // Find the inode with number inum on device dev 92*f5527388Srsc // and return an in-memory copy. Loads the inode 93*f5527388Srsc // from disk into the in-core table if necessary. 94*f5527388Srsc // The returned inode has busy set and has its ref count incremented. 95*f5527388Srsc // Caller must iput the return value when done with it. 9611a9947fSrtm struct inode* 9711a9947fSrtm iget(uint dev, uint inum) 9811a9947fSrtm { 9917e3cf15Srtm struct inode *ip, *nip; 10011a9947fSrtm struct dinode *dip; 10111a9947fSrtm struct buf *bp; 10211a9947fSrtm 10311a9947fSrtm acquire(&inode_table_lock); 10411a9947fSrtm 10511a9947fSrtm loop: 10617e3cf15Srtm nip = 0; 10711a9947fSrtm for(ip = &inode[0]; ip < &inode[NINODE]; ip++){ 10811a9947fSrtm if(ip->count > 0 && ip->dev == dev && ip->inum == inum){ 10911a9947fSrtm if(ip->busy){ 11011a9947fSrtm sleep(ip, &inode_table_lock); 11111a9947fSrtm goto loop; 11211a9947fSrtm } 11311a9947fSrtm ip->count++; 11417a85657Srtm ip->busy = 1; 11511a9947fSrtm release(&inode_table_lock); 11611a9947fSrtm return ip; 11711a9947fSrtm } 11811a9947fSrtm if(nip == 0 && ip->count == 0) 11911a9947fSrtm nip = ip; 12011a9947fSrtm } 12111a9947fSrtm 12211a9947fSrtm if(nip == 0) 12311a9947fSrtm panic("out of inodes"); 12411a9947fSrtm 12511a9947fSrtm nip->dev = dev; 12611a9947fSrtm nip->inum = inum; 12711a9947fSrtm nip->count = 1; 12811a9947fSrtm nip->busy = 1; 12911a9947fSrtm 13011a9947fSrtm release(&inode_table_lock); 13111a9947fSrtm 13224111398Skaashoek bp = bread(dev, IBLOCK(inum)); 13311a9947fSrtm dip = &((struct dinode*)(bp->data))[inum % IPB]; 13411a9947fSrtm nip->type = dip->type; 135e8d11c2eSkaashoek nip->major = dip->major; 136e8d11c2eSkaashoek nip->minor = dip->minor; 13711a9947fSrtm nip->nlink = dip->nlink; 13811a9947fSrtm nip->size = dip->size; 13911a9947fSrtm memmove(nip->addrs, dip->addrs, sizeof(nip->addrs)); 14011a9947fSrtm brelse(bp); 14111a9947fSrtm 14211a9947fSrtm return nip; 14311a9947fSrtm } 14411a9947fSrtm 14528d9ef04Skaashoek void 14628d9ef04Skaashoek iupdate(struct inode *ip) 14728d9ef04Skaashoek { 14828d9ef04Skaashoek struct buf *bp; 14928d9ef04Skaashoek struct dinode *dip; 15028d9ef04Skaashoek 15128d9ef04Skaashoek bp = bread(ip->dev, IBLOCK(ip->inum)); 15228d9ef04Skaashoek dip = &((struct dinode*)(bp->data))[ip->inum % IPB]; 15328d9ef04Skaashoek dip->type = ip->type; 15428d9ef04Skaashoek dip->major = ip->major; 15528d9ef04Skaashoek dip->minor = ip->minor; 15628d9ef04Skaashoek dip->nlink = ip->nlink; 15728d9ef04Skaashoek dip->size = ip->size; 15828d9ef04Skaashoek memmove(dip->addrs, ip->addrs, sizeof(ip->addrs)); 15905e97551Srtm bwrite(bp, IBLOCK(ip->inum)); // mark it allocated on the disk 16028d9ef04Skaashoek brelse(bp); 16128d9ef04Skaashoek } 16228d9ef04Skaashoek 163e8d11c2eSkaashoek struct inode* 164e8d11c2eSkaashoek ialloc(uint dev, short type) 165e8d11c2eSkaashoek { 166e8d11c2eSkaashoek struct inode *ip; 167e8d11c2eSkaashoek struct dinode *dip = 0; 168e8d11c2eSkaashoek struct superblock *sb; 169e8d11c2eSkaashoek int ninodes; 170e8d11c2eSkaashoek int inum; 171e8d11c2eSkaashoek struct buf *bp; 172e8d11c2eSkaashoek 173e8d11c2eSkaashoek bp = bread(dev, 1); 17424111398Skaashoek sb = (struct superblock*) bp->data; 175e8d11c2eSkaashoek ninodes = sb->ninodes; 176e8d11c2eSkaashoek brelse(bp); 177e8d11c2eSkaashoek 178e8d11c2eSkaashoek for(inum = 1; inum < ninodes; inum++) { // loop over inode blocks 17924111398Skaashoek bp = bread(dev, IBLOCK(inum)); 180e8d11c2eSkaashoek dip = &((struct dinode*)(bp->data))[inum % IPB]; 181e8d11c2eSkaashoek if(dip->type == 0) { // a free inode 182e8d11c2eSkaashoek break; 183e8d11c2eSkaashoek } 184e8d11c2eSkaashoek brelse(bp); 185e8d11c2eSkaashoek } 186e8d11c2eSkaashoek 18717e3cf15Srtm if(inum >= ninodes) 1882aa4c3bcSrtm panic("ialloc: no inodes left"); 189e8d11c2eSkaashoek 1902aa4c3bcSrtm memset(dip, 0, sizeof(*dip)); 191e8d11c2eSkaashoek dip->type = type; 19205e97551Srtm bwrite(bp, IBLOCK(inum)); // mark it allocated on the disk 193e8d11c2eSkaashoek brelse(bp); 194e8d11c2eSkaashoek ip = iget(dev, inum); 195e8d11c2eSkaashoek return ip; 196e8d11c2eSkaashoek } 197e8d11c2eSkaashoek 19828d9ef04Skaashoek static void 19924437cd5Skaashoek ifree(struct inode *ip) 200e8d11c2eSkaashoek { 20128d9ef04Skaashoek ip->type = 0; 20228d9ef04Skaashoek iupdate(ip); 203e8d11c2eSkaashoek } 204e8d11c2eSkaashoek 20511a9947fSrtm void 2069d3fb671Srtm ilock(struct inode *ip) 2079d3fb671Srtm { 2089d3fb671Srtm if(ip->count < 1) 2099d3fb671Srtm panic("ilock"); 2109d3fb671Srtm 2119d3fb671Srtm acquire(&inode_table_lock); 2129d3fb671Srtm 2139d3fb671Srtm while(ip->busy) 2149d3fb671Srtm sleep(ip, &inode_table_lock); 2159d3fb671Srtm ip->busy = 1; 2169d3fb671Srtm 2179d3fb671Srtm release(&inode_table_lock); 2189d3fb671Srtm } 2199d3fb671Srtm 2209d3fb671Srtm // caller is holding onto a reference to this inode, but no 2219d3fb671Srtm // longer needs to examine or change it, so clear ip->busy. 2229d3fb671Srtm void 2239d3fb671Srtm iunlock(struct inode *ip) 2249d3fb671Srtm { 22517e3cf15Srtm if(ip->busy != 1 || ip->count < 1) 2269d3fb671Srtm panic("iunlock"); 2279d3fb671Srtm 2289d3fb671Srtm acquire(&inode_table_lock); 2299d3fb671Srtm 2309d3fb671Srtm ip->busy = 0; 2319d3fb671Srtm wakeup(ip); 2329d3fb671Srtm 2339d3fb671Srtm release(&inode_table_lock); 2349d3fb671Srtm } 2359d3fb671Srtm 23622bac2cbSkaashoek uint 23722bac2cbSkaashoek bmap(struct inode *ip, uint bn) 23822bac2cbSkaashoek { 23922bac2cbSkaashoek unsigned x; 240ea2909b6Skaashoek uint *a; 241ea2909b6Skaashoek struct buf *inbp; 24222bac2cbSkaashoek 243ea2909b6Skaashoek if(bn >= MAXFILE) 24422bac2cbSkaashoek panic("bmap 1"); 245ea2909b6Skaashoek if(bn < NDIRECT) { 24622bac2cbSkaashoek x = ip->addrs[bn]; 24722bac2cbSkaashoek if(x == 0) 24822bac2cbSkaashoek panic("bmap 2"); 249ea2909b6Skaashoek } else { 2505051da6dSrtm if(ip->addrs[INDIRECT] == 0) 2515051da6dSrtm panic("bmap 3"); 2521be76685Skaashoek inbp = bread(ip->dev, ip->addrs[INDIRECT]); 253ea2909b6Skaashoek a = (uint*) inbp->data; 254ea2909b6Skaashoek x = a[bn - NDIRECT]; 255ea2909b6Skaashoek brelse(inbp); 256ea2909b6Skaashoek if(x == 0) 2575051da6dSrtm panic("bmap 4"); 258ea2909b6Skaashoek } 25922bac2cbSkaashoek return x; 26022bac2cbSkaashoek } 26122bac2cbSkaashoek 26222bac2cbSkaashoek void 2632aa4c3bcSrtm itrunc(struct inode *ip) 26422bac2cbSkaashoek { 265ea2909b6Skaashoek int i, j; 2661be76685Skaashoek struct buf *inbp; 26722bac2cbSkaashoek 268ea2909b6Skaashoek for(i = 0; i < NADDRS; i++) { 26922bac2cbSkaashoek if(ip->addrs[i] != 0) { 270ea2909b6Skaashoek if(i == INDIRECT) { 2711be76685Skaashoek inbp = bread(ip->dev, ip->addrs[INDIRECT]); 2721be76685Skaashoek uint *a = (uint*) inbp->data; 273bcfb84b6Srtm for(j = 0; j < NINDIRECT; j++) { 274ea2909b6Skaashoek if(a[j] != 0) { 275ea2909b6Skaashoek bfree(ip->dev, a[j]); 276ea2909b6Skaashoek a[j] = 0; 277ea2909b6Skaashoek } 278ea2909b6Skaashoek } 2791be76685Skaashoek brelse(inbp); 280ea2909b6Skaashoek } 28122bac2cbSkaashoek bfree(ip->dev, ip->addrs[i]); 28222bac2cbSkaashoek ip->addrs[i] = 0; 28322bac2cbSkaashoek } 28422bac2cbSkaashoek } 28522bac2cbSkaashoek ip->size = 0; 28622bac2cbSkaashoek iupdate(ip); 28722bac2cbSkaashoek } 28822bac2cbSkaashoek 2899d3fb671Srtm // caller is releasing a reference to this inode. 2909d3fb671Srtm // you must have the inode lock. 2919d3fb671Srtm void 29211a9947fSrtm iput(struct inode *ip) 29311a9947fSrtm { 2949d3fb671Srtm if(ip->count < 1 || ip->busy != 1) 2959d3fb671Srtm panic("iput"); 2969d3fb671Srtm 2972aa4c3bcSrtm if((ip->count == 1) && (ip->nlink == 0)) { 2982aa4c3bcSrtm itrunc(ip); 2992aa4c3bcSrtm ifree(ip); 3002aa4c3bcSrtm } 30122bac2cbSkaashoek 30211a9947fSrtm acquire(&inode_table_lock); 30311a9947fSrtm 30411a9947fSrtm ip->count -= 1; 30511a9947fSrtm ip->busy = 0; 30611a9947fSrtm wakeup(ip); 30711a9947fSrtm 30811a9947fSrtm release(&inode_table_lock); 30911a9947fSrtm } 3109d3fb671Srtm 3119d3fb671Srtm void 31232630628Srtm idecref(struct inode *ip) 3139d3fb671Srtm { 314211ff0c6Srtm ilock(ip); 315211ff0c6Srtm iput(ip); 3169d3fb671Srtm } 3179d3fb671Srtm 3181f544842Skaashoek void 319e958c538Skaashoek iincref(struct inode *ip) 320e958c538Skaashoek { 321e958c538Skaashoek ilock(ip); 322e958c538Skaashoek ip->count++; 323e958c538Skaashoek iunlock(ip); 324e958c538Skaashoek } 325e958c538Skaashoek 326e958c538Skaashoek void 3271f544842Skaashoek stati(struct inode *ip, struct stat *st) 3281f544842Skaashoek { 3291f544842Skaashoek st->st_dev = ip->dev; 3301f544842Skaashoek st->st_ino = ip->inum; 3311f544842Skaashoek st->st_type = ip->type; 3321f544842Skaashoek st->st_nlink = ip->nlink; 3331f544842Skaashoek st->st_size = ip->size; 3341f544842Skaashoek } 3351f544842Skaashoek 33622bac2cbSkaashoek #define min(a, b) ((a) < (b) ? (a) : (b)) 33722bac2cbSkaashoek 338c59361f1Srtm int 33917a85657Srtm readi(struct inode *ip, char *dst, uint off, uint n) 340c59361f1Srtm { 341c59361f1Srtm uint target = n, n1; 342c59361f1Srtm struct buf *bp; 343c59361f1Srtm 344939f9edeSkaashoek if(ip->type == T_DEV) { 345939f9edeSkaashoek if(ip->major < 0 || ip->major >= NDEV || !devsw[ip->major].d_read) 346939f9edeSkaashoek return -1; 34717a85657Srtm return devsw[ip->major].d_read(ip->minor, dst, n); 348939f9edeSkaashoek } 349939f9edeSkaashoek 350c59361f1Srtm while(n > 0 && off < ip->size){ 35124111398Skaashoek bp = bread(ip->dev, bmap(ip, off / BSIZE)); 352c59361f1Srtm n1 = min(n, ip->size - off); 35324111398Skaashoek n1 = min(n1, BSIZE - (off % BSIZE)); 35424111398Skaashoek memmove(dst, bp->data + (off % BSIZE), n1); 355c59361f1Srtm n -= n1; 356c59361f1Srtm off += n1; 357c59361f1Srtm dst += n1; 358c59361f1Srtm brelse(bp); 359c59361f1Srtm } 360c59361f1Srtm 361c59361f1Srtm return target - n; 362c59361f1Srtm } 363c59361f1Srtm 3641be76685Skaashoek static int 365ea2909b6Skaashoek newblock(struct inode *ip, uint lbn) 366ea2909b6Skaashoek { 367ea2909b6Skaashoek struct buf *inbp; 368ea2909b6Skaashoek uint *inaddrs; 369ea2909b6Skaashoek uint b; 370ea2909b6Skaashoek 371ea2909b6Skaashoek if(lbn < NDIRECT) { 372ea2909b6Skaashoek if(ip->addrs[lbn] == 0) { 373ea2909b6Skaashoek b = balloc(ip->dev); 374ea2909b6Skaashoek if(b <= 0) return -1; 375ea2909b6Skaashoek ip->addrs[lbn] = b; 376ea2909b6Skaashoek } 377ea2909b6Skaashoek } else { 378ea2909b6Skaashoek if(ip->addrs[INDIRECT] == 0) { 379ea2909b6Skaashoek b = balloc(ip->dev); 380ea2909b6Skaashoek if(b <= 0) return -1; 381ea2909b6Skaashoek ip->addrs[INDIRECT] = b; 382ea2909b6Skaashoek } 3831be76685Skaashoek inbp = bread(ip->dev, ip->addrs[INDIRECT]); 384ea2909b6Skaashoek inaddrs = (uint*) inbp->data; 385ea2909b6Skaashoek if(inaddrs[lbn - NDIRECT] == 0) { 386ea2909b6Skaashoek b = balloc(ip->dev); 387ea2909b6Skaashoek if(b <= 0) return -1; 388ea2909b6Skaashoek inaddrs[lbn - NDIRECT] = b; 3891be76685Skaashoek bwrite(inbp, ip->addrs[INDIRECT]); 390ea2909b6Skaashoek } 391ea2909b6Skaashoek brelse(inbp); 392ea2909b6Skaashoek } 393ea2909b6Skaashoek return 0; 394ea2909b6Skaashoek } 395ea2909b6Skaashoek 396ea2909b6Skaashoek int 39717a85657Srtm writei(struct inode *ip, char *addr, uint off, uint n) 3986fa5ffb5Skaashoek { 3996fa5ffb5Skaashoek if(ip->type == T_DEV) { 400939f9edeSkaashoek if(ip->major < 0 || ip->major >= NDEV || !devsw[ip->major].d_write) 401939f9edeSkaashoek return -1; 4026fa5ffb5Skaashoek return devsw[ip->major].d_write(ip->minor, addr, n); 403ea2909b6Skaashoek } else if(ip->type == T_FILE || ip->type == T_DIR) { 40428d9ef04Skaashoek struct buf *bp; 40528d9ef04Skaashoek int r = 0; 40628d9ef04Skaashoek int m; 40728d9ef04Skaashoek int lbn; 40828d9ef04Skaashoek while(r < n) { 40928d9ef04Skaashoek lbn = off / BSIZE; 410ea2909b6Skaashoek if(lbn >= MAXFILE) return r; 411ea2909b6Skaashoek if(newblock(ip, lbn) < 0) { 412ea2909b6Skaashoek cprintf("newblock failed\n"); 413ea2909b6Skaashoek return r; 41428d9ef04Skaashoek } 41522bac2cbSkaashoek m = min(BSIZE - off % BSIZE, n-r); 416ea2909b6Skaashoek bp = bread(ip->dev, bmap(ip, lbn)); 41728d9ef04Skaashoek memmove(bp->data + off % BSIZE, addr, m); 418ea2909b6Skaashoek bwrite(bp, bmap(ip, lbn)); 41928d9ef04Skaashoek brelse(bp); 42028d9ef04Skaashoek r += m; 42128d9ef04Skaashoek off += m; 42228d9ef04Skaashoek } 42328d9ef04Skaashoek if(r > 0) { 42428d9ef04Skaashoek if(off > ip->size) { 425bdb66433Skaashoek if(ip->type == T_DIR) ip->size = ((off / BSIZE) + 1) * BSIZE; 426bdb66433Skaashoek else ip->size = off; 42728d9ef04Skaashoek } 42828d9ef04Skaashoek iupdate(ip); 42928d9ef04Skaashoek } 43028d9ef04Skaashoek return r; 4316fa5ffb5Skaashoek } else { 4322aa4c3bcSrtm panic("writei: unknown type"); 4338a8be1b8Srtm return 0; 4346fa5ffb5Skaashoek } 4356fa5ffb5Skaashoek } 4366fa5ffb5Skaashoek 437211ff0c6Srtm // look up a path name, in one of three modes. 438211ff0c6Srtm // NAMEI_LOOKUP: return locked target inode. 439211ff0c6Srtm // NAMEI_CREATE: return locked parent inode. 4405051da6dSrtm // return 0 if name does exist. 4415051da6dSrtm // *ret_last points to last path component (i.e. new file name). 4425051da6dSrtm // *ret_ip points to the the name that did exist, if it did. 4435051da6dSrtm // *ret_ip and *ret_last may be zero even if return value is zero. 444211ff0c6Srtm // NAMEI_DELETE: return locked parent inode, offset of dirent in *ret_off. 445211ff0c6Srtm // return 0 if name doesn't exist. 4469d3fb671Srtm struct inode* 4475051da6dSrtm namei(char *path, int mode, uint *ret_off, char **ret_last, struct inode **ret_ip) 4489d3fb671Srtm { 4499d3fb671Srtm struct inode *dp; 4508787cd01Skaashoek struct proc *p = curproc[cpu()]; 451211ff0c6Srtm char *cp = path, *cp1; 4529d3fb671Srtm uint off, dev; 4539d3fb671Srtm struct buf *bp; 4549d3fb671Srtm struct dirent *ep; 455211ff0c6Srtm int i, atend; 4569d3fb671Srtm unsigned ninum; 4579d3fb671Srtm 4585051da6dSrtm if(ret_off) 4595051da6dSrtm *ret_off = 0xffffffff; 4605051da6dSrtm if(ret_last) 4615051da6dSrtm *ret_last = 0; 4625051da6dSrtm if(ret_ip) 4635051da6dSrtm *ret_ip = 0; 4645051da6dSrtm 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; 4795051da6dSrtm if(mode == NAMEI_CREATE && ret_ip){ 4805051da6dSrtm *ret_ip = dp; 4815051da6dSrtm return 0; 4825051da6dSrtm } 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; 50203c70cc2Srtm if((cp[i] == '\0' || cp[i] == '/' || i >= DIRSIZ) && 50303c70cc2Srtm (i >= DIRSIZ || ep->name[i] == '\0')){ 50403c70cc2Srtm while(cp[i] != '\0' && cp[i] != '/') 50503c70cc2Srtm i++; 506211ff0c6Srtm off += (uchar*)ep - bp->data; 5079d3fb671Srtm ninum = ep->inum; 5089d3fb671Srtm brelse(bp); 5099d3fb671Srtm cp += i; 5109d3fb671Srtm goto found; 5119d3fb671Srtm } 5129d3fb671Srtm } 5139d3fb671Srtm brelse(bp); 5149d3fb671Srtm } 515211ff0c6Srtm atend = 1; 516211ff0c6Srtm for(cp1 = cp; *cp1; cp1++) 517211ff0c6Srtm if(*cp1 == '/') 518211ff0c6Srtm atend = 0; 5195051da6dSrtm if(mode == NAMEI_CREATE && atend){ 5205051da6dSrtm if(*cp == '\0'){ 5215051da6dSrtm iput(dp); 5225051da6dSrtm return 0; 5235051da6dSrtm } 5245051da6dSrtm *ret_last = cp; 525211ff0c6Srtm return dp; 5265051da6dSrtm } 527211ff0c6Srtm 5289d3fb671Srtm iput(dp); 5299d3fb671Srtm return 0; 5309d3fb671Srtm 5319d3fb671Srtm found: 532211ff0c6Srtm if(mode == NAMEI_DELETE && *cp == '\0'){ 533211ff0c6Srtm *ret_off = off; 534211ff0c6Srtm return dp; 535211ff0c6Srtm } 5369d3fb671Srtm dev = dp->dev; 5379d3fb671Srtm iput(dp); 5389d3fb671Srtm dp = iget(dev, ninum); 5397ce01cf9Srtm if(dp->type == 0 || dp->nlink < 1) 5407ce01cf9Srtm panic("namei"); 5419d3fb671Srtm while(*cp == '/') 5429d3fb671Srtm cp++; 5439d3fb671Srtm } 5449d3fb671Srtm } 545e8d11c2eSkaashoek 5469e5970d5Srtm void 5479e5970d5Srtm wdir(struct inode *dp, char *name, uint ino) 5489e5970d5Srtm { 5499e5970d5Srtm uint off; 550e4bcd2a3Srtm struct dirent de; 5519e5970d5Srtm int i; 5529e5970d5Srtm 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; 5612aa4c3bcSrtm for(i = 0; i < DIRSIZ && name[i]; i++) 562e4bcd2a3Srtm de.name[i] = name[i]; 5639e5970d5Srtm for( ; i < DIRSIZ; i++) 564e4bcd2a3Srtm de.name[i] = '\0'; 565e4bcd2a3Srtm 566e4bcd2a3Srtm if(writei(dp, (char*) &de, off, sizeof(de)) != sizeof(de)) 567e4bcd2a3Srtm panic("wdir write"); 5689e5970d5Srtm } 5699e5970d5Srtm 570e8d11c2eSkaashoek struct inode* 5710633b971Skaashoek mknod(char *cp, short type, short major, short minor) 572e8d11c2eSkaashoek { 5730633b971Skaashoek struct inode *ip, *dp; 5745051da6dSrtm char *last; 575e8d11c2eSkaashoek 5765051da6dSrtm if((dp = namei(cp, NAMEI_CREATE, 0, &last, 0)) == 0) 5770633b971Skaashoek return 0; 578211ff0c6Srtm 5795051da6dSrtm ip = mknod1(dp, last, type, major, minor); 5805051da6dSrtm 5815051da6dSrtm iput(dp); 5825051da6dSrtm 5835051da6dSrtm return ip; 5845051da6dSrtm } 5855051da6dSrtm 5865051da6dSrtm struct inode* 5875051da6dSrtm mknod1(struct inode *dp, char *name, short type, short major, short minor) 5885051da6dSrtm { 5895051da6dSrtm struct inode *ip; 5905051da6dSrtm 591e8d11c2eSkaashoek ip = ialloc(dp->dev, type); 5922aa4c3bcSrtm if(ip == 0) 5930633b971Skaashoek return 0; 594e8d11c2eSkaashoek ip->major = major; 595e8d11c2eSkaashoek ip->minor = minor; 5966c0e444fSkaashoek ip->size = 0; 5977ce01cf9Srtm ip->nlink = 1; 5986c0e444fSkaashoek 5996c0e444fSkaashoek iupdate(ip); // write new inode to disk 600e8d11c2eSkaashoek 6015051da6dSrtm wdir(dp, name, ip->inum); 6025051da6dSrtm 603e8d11c2eSkaashoek return ip; 604e8d11c2eSkaashoek } 60524437cd5Skaashoek 60624437cd5Skaashoek int 60724437cd5Skaashoek unlink(char *cp) 60824437cd5Skaashoek { 609211ff0c6Srtm struct inode *ip, *dp; 610211ff0c6Srtm struct dirent de; 61117e3cf15Srtm uint off, inum, dev; 61224437cd5Skaashoek 6135051da6dSrtm dp = namei(cp, NAMEI_DELETE, &off, 0, 0); 6145051da6dSrtm if(dp == 0) 61524437cd5Skaashoek return -1; 61624437cd5Skaashoek 61717e3cf15Srtm dev = dp->dev; 61817e3cf15Srtm 61917e3cf15Srtm if(readi(dp, (char*)&de, off, sizeof(de)) != sizeof(de) || de.inum == 0) 620211ff0c6Srtm panic("unlink no entry"); 62117e3cf15Srtm 622211ff0c6Srtm inum = de.inum; 62324437cd5Skaashoek 624211ff0c6Srtm memset(&de, 0, sizeof(de)); 625211ff0c6Srtm if(writei(dp, (char*)&de, off, sizeof(de)) != sizeof(de)) 626211ff0c6Srtm panic("unlink dir write"); 62724437cd5Skaashoek 62824437cd5Skaashoek iupdate(dp); 62924437cd5Skaashoek iput(dp); 630211ff0c6Srtm 63117e3cf15Srtm ip = iget(dev, inum); 632211ff0c6Srtm 633bcfb84b6Srtm if(ip->nlink < 1) 634bcfb84b6Srtm panic("unlink nlink < 1"); 635bcfb84b6Srtm 636211ff0c6Srtm ip->nlink--; 637211ff0c6Srtm 638211ff0c6Srtm iupdate(ip); 63922bac2cbSkaashoek iput(ip); 640211ff0c6Srtm 64124437cd5Skaashoek return 0; 64224437cd5Skaashoek } 6439e5970d5Srtm 6449e5970d5Srtm int 6459e5970d5Srtm link(char *name1, char *name2) 6469e5970d5Srtm { 647211ff0c6Srtm struct inode *ip, *dp; 6485051da6dSrtm char *last; 6499e5970d5Srtm 6505051da6dSrtm if((ip = namei(name1, NAMEI_LOOKUP, 0, 0, 0)) == 0) 6519e5970d5Srtm return -1; 652211ff0c6Srtm if(ip->type == T_DIR){ 653211ff0c6Srtm iput(ip); 654211ff0c6Srtm return -1; 655211ff0c6Srtm } 6569e5970d5Srtm 657211ff0c6Srtm iunlock(ip); 658211ff0c6Srtm 6595051da6dSrtm if((dp = namei(name2, NAMEI_CREATE, 0, &last, 0)) == 0) { 660211ff0c6Srtm idecref(ip); 661211ff0c6Srtm return -1; 662211ff0c6Srtm } 663211ff0c6Srtm if(dp->dev != ip->dev){ 664211ff0c6Srtm idecref(ip); 665211ff0c6Srtm iput(dp); 666211ff0c6Srtm return -1; 667211ff0c6Srtm } 668211ff0c6Srtm 669211ff0c6Srtm ilock(ip); 6709e5970d5Srtm ip->nlink += 1; 6719e5970d5Srtm iupdate(ip); 6729e5970d5Srtm 6735051da6dSrtm wdir(dp, last, ip->inum); 6749e5970d5Srtm iput(dp); 6759e5970d5Srtm iput(ip); 6769e5970d5Srtm 6779e5970d5Srtm return 0; 6789e5970d5Srtm } 679