1992/0129/port/devwren.c (diff list | history)

port/devwren.c on 1991/0110
1991/0110		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h"
1992/0111		#include "../port/error.h"
1991/0110		#include "devtab.h" #include "io.h"
1991/0927		#define DATASIZE (8*1024)
1991/0823		typedef struct Partition Partition; typedef struct Drive Drive;
1991/0112
1991/0110		enum {
1991/0823		Npart= 8+2, /* 8 sub partitions, disk, and partition */
1991/1019		Ndisk= 64, /* maximum disks; if you change it, you must map from dev to disk */
1991/0110
1991/0823		/* file types */
1991/0112		Qdir= 0,
1991/0110		};
1991/0823		#define PART(x) ((x)&0xF)
1991/0927		#define DRIVE(x) (((x)>>4)&(Ndisk-1))
1991/0823		#define MKQID(d,p) (((d)<<4) | (p))
1991/0110
1991/0823		struct Partition
1991/0112		{
1991/0823		ulong start; ulong end; char name[NAMELEN+1];
1991/0112		};
1991/0823		struct Drive
1991/0112		{
1991/0823		ulong bytes; /* bytes per block */ int npart; /* actual number of partitions */ int drive; Partition p[Npart];
1991/0112		};
1991/0110
1991/0823		static Drive wren[Ndisk];
1991/0110
1991/0823		static void wrenpart(int);
1991/1203		static long wrenio(Chan*, int, char*, ulong, ulong);
1991/0115
1991/0110		/* * accepts [0-7].[0-7], or abbreviation */ static int wrendev(char *p) {
1991/1019		int drive, unit;
1991/0823
1991/1019		if(p == 0 || p[0] == '\0') return 0;
1991/0823		if(p[0] < '0' || p[0] > '7')
1992/0114		error(Ebadarg);
1991/1019		drive = p[0] - '0'; unit = 0; if(p[1]){ if(p[1] != '.' || p[2] < '0' || p[2] > '7' || p[3] != '\0')
1992/0114		error(Ebadarg);
1991/1019		unit = p[2] - '0'; } return (drive << 3) | unit;
1991/0110		} static int
1991/0823		wrengen(Chan *c, Dirtab *tab, long ntab, long s, Dir *dirp)
1991/0110		{
1991/0823		Qid qid; int drive; char name[NAMELEN+4]; Drive *dp; Partition *pp; ulong l;
1991/0112
1991/0823		qid.vers = 0;
1991/0927		drive = c->dev;
1991/0823		if(drive >= Ndisk)
1991/0110		return -1;
1991/0823		dp = &wren[drive];
1991/0112
1991/0823		if(s >= dp->npart)
1991/0927		return -1;
1991/0823		pp = &dp->p[s];
1991/0927		if(drive & 7) sprint(name, "hd%d.%d%s", drive>>3, drive&7, pp->name); else sprint(name, "hd%d%s", drive>>3, pp->name);
1991/0823		name[NAMELEN] = 0; qid.path = MKQID(drive, s); l = (pp->end - pp->start) * dp->bytes;
1991/1112		devdir(c, qid, name, l, eve, 0666, dirp);
1991/0110		return 1; } void wrenreset(void)
1991/0112		{ }
1991/0110		void wreninit(void)
1991/0823		{ }
1991/0110		/* * param is #r<target>.<lun> */ Chan * wrenattach(char *param) { Chan *c;
1991/0823		int drive;
1991/0112
1991/0823		drive = wrendev(param); wrenpart(drive);
1991/0921		c = devattach('w', param);
1991/0823		c->dev = drive;
1991/0110		return c; }
1991/0823		Chan*
1991/0110		wrenclone(Chan *c, Chan *nc) { return devclone(c, nc); } int wrenwalk(Chan *c, char *name) {
1991/0823		return devwalk(c, name, 0, 0, wrengen);
1991/0110		} void
1991/0823		wrenstat(Chan *c, char *dp)
1991/0110		{
1991/0823		devstat(c, dp, 0, 0, wrengen);
1991/0110		}
1991/0823		Chan*
1991/0110		wrenopen(Chan *c, int omode) {
1991/0823		return devopen(c, omode, 0, 0, wrengen);
1991/0110		} void wrencreate(Chan *c, char *name, int omode, ulong perm) {
1991/1210		USED(c, name, omode, perm);
1991/0110		error(Eperm); } void wrenclose(Chan *c)
1991/0823		{
1991/1210		USED(c);
1991/0823		}
1991/0110
1991/0823		void wrenremove(Chan *c) {
1991/1210		USED(c);
1991/0823		error(Eperm); } void wrenwstat(Chan *c, char *dp) {
1991/1210		USED(c, dp);
1991/0823		error(Eperm); }
1991/0110		long
1991/0411		wrenread(Chan *c, char *a, long n, ulong offset)
1991/0110		{
1991/0112		if(c->qid.path == CHDIR)
1991/0823		return devdirread(c, a, n, 0, 0, wrengen);
1991/1203		return wrenio(c, 0, a, n, offset);
1991/0110		} long
1991/0411		wrenwrite(Chan *c, char *a, long n, ulong offset)
1991/0110		{
1992/0129		n = wrenio(c, 1, a, n, offset); if(n) return n; error("end of device");
1991/1203		} static long wrenio(Chan *c, int write, char *a, ulong len, ulong offset) {
1991/0823		Drive *d; Partition *p;
1991/1203		Scsibuf *b; ulong block, n, max, x;
1991/0823		d = &wren[DRIVE(c->qid.path)];
1992/0114		if(d->npart == 0) /* drive repartitioned */ error(Eio);
1991/0823		p = &d->p[PART(c->qid.path)]; block = offset / d->bytes + p->start;
1991/1203		n = (offset + len + d->bytes - 1) / d->bytes + p->start - block; max = DATASIZE / d->bytes; if(n > max) n = max;
1991/0823		if(block + n > p->end) n = p->end - block;
1991/1203		if(block >= p->end || n == 0)
1991/0823		return 0;
1991/0927		b = scsibuf();
1991/0823		if(waserror()){
1991/0927		scsifree(b);
1991/0823		nexterror();
1991/0110		}
1991/1203		offset %= d->bytes;
1991/0927		if(write){
1991/1203		if(offset || len % d->bytes){ x = scsibread(d->drive, b, n, d->bytes, block); if(x < n * d->bytes){ n = x / d->bytes; x = n * d->bytes - offset; if(len > x) len = x; } } memmove((char*)b->virt + offset, a, len); x = scsibwrite(d->drive, b, n, d->bytes, block); if(x < offset) len = 0; else if(len > x - offset) len = x - offset;
1991/0927		}else{
1991/1203		x = scsibread(d->drive, b, n, d->bytes, block); if(x < offset) len = 0; else if(len > x - offset) len = x - offset; memmove(a, (char*)b->virt + offset, len);
1991/0927		}
1991/0823		poperror();
1991/0927		scsifree(b);
1991/1203		return len;
1991/0110		}
1991/0823		/* * read partition table. The partition table is just ascii strings. */ #define MAGIC "plan9 partitions" static void wrenpart(int dev)
1991/0110		{
1991/0823		Drive *dp; Partition *pp; uchar buf[32];
1991/0927		Scsibuf *b; char *rawpart, *line[Npart+1], *field[3];
1991/0823		ulong n; int i;
1991/0110
1991/0823		scsiready(dev); scsisense(dev, buf);
1991/1220		if (scsicap(dev, buf)) error(Eio);
1991/0823		dp = &wren[dev]; dp->drive = dev;
1991/0927
1991/0823		/* * we always have a partition for the whole disk * and one for the partition table */ dp->bytes = (buf[4]<<24)+(buf[5]<<16)+(buf[6]<<8)+(buf[7]); pp = &dp->p[0]; strcpy(pp->name, "disk"); pp->start = 0; pp->end = (buf[0]<<24)+(buf[1]<<16)+(buf[2]<<8)+(buf[3]) + 1; pp++; strcpy(pp->name, "partition"); pp->start = dp->p[0].end - 1; pp->end = dp->p[0].end; dp->npart = 2;
1991/0603
1991/0823		/* * read partition table from disk, null terminate */
1991/0927		b = scsibuf();
1991/0823		if(waserror()){
1991/0927		scsifree(b);
1991/0823		nexterror(); }
1991/0927		scsibread(dev, b, 1, dp->bytes, dp->p[0].end-1); rawpart = b->virt; rawpart[dp->bytes-1] = 0;
1991/0823		/* * parse partition table. */
1991/0927		n = getfields(rawpart, line, Npart+1, '\n');
1992/0109		if(n > 0 && strncmp(line[0], MAGIC, sizeof(MAGIC)-1) == 0){
1991/0927		for(i = 1; i < n; i++){ pp++; if(getfields(line[i], field, 3, ' ') != 3){ break; } strncpy(pp->name, field[0], NAMELEN); pp->start = strtoul(field[1], 0, 0); pp->end = strtoul(field[2], 0, 0); if(pp->start > pp->end || pp->start >= dp->p[0].end){ break; } dp->npart++;
1991/0823		} } poperror();
1991/0927		scsifree(b);
1991/0110		}