1 78a779a3 2008-07-20 rsc #include <u.h>
  2 78a779a3 2008-07-20 rsc #include <libc.h>
  3 78a779a3 2008-07-20 rsc #include <auth.h>
  4 78a779a3 2008-07-20 rsc #include <fcall.h>
  5 78a779a3 2008-07-20 rsc #include "dat.h"
  6 78a779a3 2008-07-20 rsc #include "fns.h"
  7 78a779a3 2008-07-20 rsc 
  8 78a779a3 2008-07-20 rsc static Xfile*	clean(Xfile*);
  9 78a779a3 2008-07-20 rsc 
 10 78a779a3 2008-07-20 rsc #define	FIDMOD	127	/* prime */
 11 78a779a3 2008-07-20 rsc 
 12 78a779a3 2008-07-20 rsc static Xdata*	xhead;
 13 78a779a3 2008-07-20 rsc static Xfile*	xfiles[FIDMOD];
 14 78a779a3 2008-07-20 rsc static Xfile*	freelist;
 15 78a779a3 2008-07-20 rsc 
 16 78a779a3 2008-07-20 rsc Xdata*
 17 78a779a3 2008-07-20 rsc getxdata(char *name)
 18 78a779a3 2008-07-20 rsc {
 19 78a779a3 2008-07-20 rsc 	int fd;
 20 78a779a3 2008-07-20 rsc 	Dir *dir;
 21 78a779a3 2008-07-20 rsc 	Xdata *xf, *fxf;
 22 78a779a3 2008-07-20 rsc 	int flag;
 23 78a779a3 2008-07-20 rsc 
 24 78a779a3 2008-07-20 rsc 	if(name[0] == 0)
 25 78a779a3 2008-07-20 rsc 		name = deffile;
 26 78a779a3 2008-07-20 rsc 	if(name == 0)
 27 78a779a3 2008-07-20 rsc 		error(Enofile);
 28 78a779a3 2008-07-20 rsc 	flag = (access(name, 6) == 0) ? ORDWR : OREAD;
 29 78a779a3 2008-07-20 rsc 	fd = open(name, flag);
 30 78a779a3 2008-07-20 rsc 	if(fd < 0)
 31 78a779a3 2008-07-20 rsc 		error(Enonexist);
 32 78a779a3 2008-07-20 rsc 	dir = nil;
 33 78a779a3 2008-07-20 rsc 	if(waserror()){
 34 78a779a3 2008-07-20 rsc 		close(fd);
 35 78a779a3 2008-07-20 rsc 		free(dir);
 36 78a779a3 2008-07-20 rsc 		nexterror();
 37 78a779a3 2008-07-20 rsc 	}
 38 78a779a3 2008-07-20 rsc 	if((dir = dirfstat(fd)) == nil)
 39 78a779a3 2008-07-20 rsc 		error("I/O error");
 40 78a779a3 2008-07-20 rsc 	if((dir->qid.type & ~QTTMP) != QTFILE)
 41 78a779a3 2008-07-20 rsc 		error("attach name not a plain file");
 42 78a779a3 2008-07-20 rsc 	for(fxf=0,xf=xhead; xf; xf=xf->next){
 43 78a779a3 2008-07-20 rsc 		if(xf->name == 0){
 44 78a779a3 2008-07-20 rsc 			if(fxf == 0)
 45 78a779a3 2008-07-20 rsc 				fxf = xf;
 46 78a779a3 2008-07-20 rsc 			continue;
 47 78a779a3 2008-07-20 rsc 		}
 48 78a779a3 2008-07-20 rsc 		if(xf->qid.path != dir->qid.path || xf->qid.vers != dir->qid.vers)
 49 78a779a3 2008-07-20 rsc 			continue;
 50 78a779a3 2008-07-20 rsc 		if(xf->type != dir->type || xf->fdev != dir->dev)
 51 78a779a3 2008-07-20 rsc 			continue;
 52 78a779a3 2008-07-20 rsc 		xf->ref++;
 53 78a779a3 2008-07-20 rsc 		chat("incref=%d, \"%s\", dev=%d...", xf->ref, xf->name, xf->dev);
 54 78a779a3 2008-07-20 rsc 		close(fd);
 55 78a779a3 2008-07-20 rsc 		poperror();
 56 78a779a3 2008-07-20 rsc 		free(dir);
 57 78a779a3 2008-07-20 rsc 		return xf;
 58 78a779a3 2008-07-20 rsc 	}
 59 78a779a3 2008-07-20 rsc 	if(fxf==0){
 60 78a779a3 2008-07-20 rsc 		fxf = ealloc(sizeof(Xfs));
 61 78a779a3 2008-07-20 rsc 		fxf->next = xhead;
 62 78a779a3 2008-07-20 rsc 		xhead = fxf;
 63 78a779a3 2008-07-20 rsc 	}
 64 78a779a3 2008-07-20 rsc 	chat("alloc \"%s\", dev=%d...", name, fd);
 65 78a779a3 2008-07-20 rsc 	fxf->ref = 1;
 66 78a779a3 2008-07-20 rsc 	fxf->name = strcpy(ealloc(strlen(name)+1), name);
 67 78a779a3 2008-07-20 rsc 	fxf->qid = dir->qid;
 68 78a779a3 2008-07-20 rsc 	fxf->type = dir->type;
 69 78a779a3 2008-07-20 rsc 	fxf->fdev = dir->dev;
 70 78a779a3 2008-07-20 rsc 	fxf->dev = fd;
 71 78a779a3 2008-07-20 rsc 	free(dir);
 72 78a779a3 2008-07-20 rsc 	poperror();
 73 78a779a3 2008-07-20 rsc 	return fxf;
 74 78a779a3 2008-07-20 rsc }
 75 78a779a3 2008-07-20 rsc 
 76 78a779a3 2008-07-20 rsc static void
 77 78a779a3 2008-07-20 rsc putxdata(Xdata *d)
 78 78a779a3 2008-07-20 rsc {
 79 78a779a3 2008-07-20 rsc 	if(d->ref <= 0)
 80 78a779a3 2008-07-20 rsc 		panic(0, "putxdata");
 81 78a779a3 2008-07-20 rsc 	d->ref--;
 82 78a779a3 2008-07-20 rsc 	chat("decref=%d, \"%s\", dev=%d...", d->ref, d->name, d->dev);
 83 78a779a3 2008-07-20 rsc 	if(d->ref == 0){
 84 78a779a3 2008-07-20 rsc 		chat("purgebuf...");
 85 78a779a3 2008-07-20 rsc 		purgebuf(d);
 86 78a779a3 2008-07-20 rsc 		close(d->dev);
 87 78a779a3 2008-07-20 rsc 		free(d->name);
 88 78a779a3 2008-07-20 rsc 		d->name = 0;
 89 78a779a3 2008-07-20 rsc 	}
 90 78a779a3 2008-07-20 rsc }
 91 78a779a3 2008-07-20 rsc 
 92 78a779a3 2008-07-20 rsc void
 93 78a779a3 2008-07-20 rsc refxfs(Xfs *xf, int delta)
 94 78a779a3 2008-07-20 rsc {
 95 78a779a3 2008-07-20 rsc 	xf->ref += delta;
 96 78a779a3 2008-07-20 rsc 	if(xf->ref == 0){
 97 78a779a3 2008-07-20 rsc 		if(xf->d)
 98 78a779a3 2008-07-20 rsc 			putxdata(xf->d);
 99 78a779a3 2008-07-20 rsc 		if(xf->ptr)
100 78a779a3 2008-07-20 rsc 			free(xf->ptr);
101 78a779a3 2008-07-20 rsc 		free(xf);
102 78a779a3 2008-07-20 rsc 	}
103 78a779a3 2008-07-20 rsc }
104 78a779a3 2008-07-20 rsc 
105 78a779a3 2008-07-20 rsc Xfile*
106 78a779a3 2008-07-20 rsc xfile(int fid, int flag)
107 78a779a3 2008-07-20 rsc {
108 78a779a3 2008-07-20 rsc 	int k = fid%FIDMOD;
109 78a779a3 2008-07-20 rsc 	Xfile **hp=&xfiles[k], *f, *pf;
110 78a779a3 2008-07-20 rsc 
111 78a779a3 2008-07-20 rsc 	for(f=*hp,pf=0; f; pf=f,f=f->next)
112 78a779a3 2008-07-20 rsc 		if(f->fid == fid)
113 78a779a3 2008-07-20 rsc 			break;
114 78a779a3 2008-07-20 rsc 	if(f && pf){
115 78a779a3 2008-07-20 rsc 		pf->next = f->next;
116 78a779a3 2008-07-20 rsc 		f->next = *hp;
117 78a779a3 2008-07-20 rsc 		*hp = f;
118 78a779a3 2008-07-20 rsc 	}
119 78a779a3 2008-07-20 rsc 	switch(flag){
120 78a779a3 2008-07-20 rsc 	default:
121 78a779a3 2008-07-20 rsc 		panic(0, "xfile");
122 78a779a3 2008-07-20 rsc 	case Asis:
123 78a779a3 2008-07-20 rsc 		if(f == 0)
124 78a779a3 2008-07-20 rsc 			error("unassigned fid");
125 78a779a3 2008-07-20 rsc 		return f;
126 78a779a3 2008-07-20 rsc 	case Clean:
127 78a779a3 2008-07-20 rsc 		break;
128 78a779a3 2008-07-20 rsc 	case Clunk:
129 78a779a3 2008-07-20 rsc 		if(f){
130 78a779a3 2008-07-20 rsc 			*hp = f->next;
131 78a779a3 2008-07-20 rsc 			clean(f);
132 78a779a3 2008-07-20 rsc 			f->next = freelist;
133 78a779a3 2008-07-20 rsc 			freelist = f;
134 78a779a3 2008-07-20 rsc 		}
135 78a779a3 2008-07-20 rsc 		return 0;
136 78a779a3 2008-07-20 rsc 	}
137 78a779a3 2008-07-20 rsc 	if(f)
138 78a779a3 2008-07-20 rsc 		return clean(f);
139 78a779a3 2008-07-20 rsc 	if(f = freelist)	/* assign = */
140 78a779a3 2008-07-20 rsc 		freelist = f->next;
141 78a779a3 2008-07-20 rsc 	else
142 78a779a3 2008-07-20 rsc 		f = ealloc(sizeof(Xfile));
143 78a779a3 2008-07-20 rsc 	f->next = *hp;
144 78a779a3 2008-07-20 rsc 	*hp = f;
145 78a779a3 2008-07-20 rsc 	f->xf = 0;
146 78a779a3 2008-07-20 rsc 	f->fid = fid;
147 78a779a3 2008-07-20 rsc 	f->flags = 0;
148 78a779a3 2008-07-20 rsc 	f->qid = (Qid){0,0,0};
149 78a779a3 2008-07-20 rsc 	f->len = 0;
150 78a779a3 2008-07-20 rsc 	f->ptr = 0;
151 78a779a3 2008-07-20 rsc 	return f;
152 78a779a3 2008-07-20 rsc }
153 78a779a3 2008-07-20 rsc 
154 78a779a3 2008-07-20 rsc static Xfile *
155 78a779a3 2008-07-20 rsc clean(Xfile *f)
156 78a779a3 2008-07-20 rsc {
157 78a779a3 2008-07-20 rsc 	if(f->xf){
158 78a779a3 2008-07-20 rsc 		refxfs(f->xf, -1);
159 78a779a3 2008-07-20 rsc 		f->xf = 0;
160 78a779a3 2008-07-20 rsc 	}
161 78a779a3 2008-07-20 rsc 	if(f->len){
162 78a779a3 2008-07-20 rsc 		free(f->ptr);
163 78a779a3 2008-07-20 rsc 		f->len = 0;
164 78a779a3 2008-07-20 rsc 	}
165 78a779a3 2008-07-20 rsc 	f->ptr = 0;
166 78a779a3 2008-07-20 rsc 	f->flags = 0;
167 78a779a3 2008-07-20 rsc 	f->qid = (Qid){0,0,0};
168 78a779a3 2008-07-20 rsc 	return f;
169 78a779a3 2008-07-20 rsc }