1996/0131/port/devtinyfs.c (diff list | history)

1996/0123/sys/src/9/port/devtinyfs.c:13,27 – 1996/0131/sys/src/9/port/devtinyfs.c:13,28 (short | long | prev | next)
1996/0116		enum{ Qdir,
1996/0123		Nfile= 32,
1996/0120		Qmedium,
1996/0123		Magic= 0xfeedbeef, Superlen= 64,
1996/0131		Blen= 48, Tdir= 0, Tdata, Tend,
1996/0116		};
1996/0122		typedef struct FS FS;
1996/0116
1996/0122		struct FS {
1996/0116		QLock;
1996/0122		Ref r;
1996/0123/sys/src/9/port/devtinyfs.c:28,36 – 1996/0131/sys/src/9/port/devtinyfs.c:29,36
1996/0122		int dev; FS *next;
1996/0116		Chan *c;
1996/0123		uchar *fat; ulong nclust; ulong clustsize;
1996/0131		uchar *map; int nblocks;
1996/0122		}; struct {
1996/0123/sys/src/9/port/devtinyfs.c:39,44 – 1996/0131/sys/src/9/port/devtinyfs.c:39,50
1996/0122		int hidev;
1996/0116		} tinyfs;
1996/0131		#define GETS(x) ((x)[0]|((x)[1]<<8)) #define PUTS(x, v) {(x)[0] = (v);(x)[1] = ((v)>>8);} #define GETL(x) (GETS(x)|(GETS(x+2)<<16)) #define PUTL(x, v) {PUTS(x, v);PUTS(x+2, (v)>>16)};
1996/0116		void tinyfsreset(void) {
1996/0123/sys/src/9/port/devtinyfs.c:49,60 – 1996/0131/sys/src/9/port/devtinyfs.c:55,106
1996/0116		{ }
1996/0123		#define GETS(x) ((x)[0]|((x)[1]<<8)) #define PUTS(x, v) {(x)[0] = (v);(x)[1] = ((v)>>8);}
1996/0131		static uchar checksum(uchar *p) { uchar *e; uchar s;
1996/0123		#define GETL(x) (GETS(x)|(GETS(x+2)<<16)) #define PUTL(x, v) {PUTS(x, v);PUTS(x+2, (v)>>16)};
1996/0131		s = 0; for(e = p + Blen; p < e; p++) s += *p; }
1996/0123
1996/0131		static void mapclr(FS *fs, int bno) { fs->map[bno>>3] &= ~(1<<(bno&7)); } static void mapset(FS *fs, int bno) { fs->map[bno>>3] |= 1<<(bno&7); } static int mapalloc(FS *fs) { int i, j, lim; uchar x; qlock(fs); lim = (fs->nblocks + 8 - 1)/8; for(i = 0; i < lim; i++){ x = fs->map[i]; if(x == 0xff) continue; for(j = 0; j < 8; j++) if((x & (1<<j)) == 0){ fs->map[i] = x|(1<<j); qunlock(fs); return i*8 + j; } } qunlock(fs); return -1; }
1996/0123		/* * see if we have a reasonable fat/root directory */
1996/0123/sys/src/9/port/devtinyfs.c:61,97 – 1996/0131/sys/src/9/port/devtinyfs.c:107,141
1996/0123		static int fsinit(FS *fs) { uchar buf[DIRLEN];
1996/0131		uchar buf[Blen+DIRLEN];
1996/0123		Dir d; ulong x;
1996/0131		ulong x, bno;
1996/0123		n = devtab[fs->c->type].read(fs->c, buf, Superlen, 0); if(n != Superlen) error(Eio); x = GETL(buf); if(x != Magic) return -1; fs->clustsize = GETL(buf+4); fs->nclust = GETL(buf+8); x = fs->clustsize*fs->nclust;                  devtab[fs->c->type].stat(fs->c, buf); convM2D(buf, &d); if(d.length < 128)
1996/0131		fs->nblocks = d.length/Blen; if(fs->nblocks < 3)
1996/0123		error("tinyfs medium too small"); if(d.length < x) return -1; fs->fat = smalloc(2*fs->nclust); n = devtab[fs->c->type].read(fs->c, buf, 2*fs->nclust, Superlen); fd(n != 2*fs->nclust) error(Eio);
1996/0131		/* bitmap for block usage */ x = (fs->nblocks + 8 - 1)/8; fs->map = malloc(x); memset(fs->map, 0x0, x); for(bno = fs->nblocks; bno < x*8; bno++) mapset(fs, bno);
1996/0123		x = GETS(fs->fat); if(x == 0) return -1;                  return 0;
1996/0131		for(bno = 0; bno < fs->nblocks; bno++){ n = devtab[fs->c->type].read(fs->c, buf, Blen, Blen*bno); if(n != Blen) break; if(checksum(buf) != 0) continue; switch(buf[0]){ case Tdir: mapset(fs, bno); break; } }
1996/0123		} /*