ref: 0f8168038af32828fcdc39575dea0e4de0c01122
dir: /sys/src/cmd/ext2srv/xfile.c/
#include <u.h> #include <libc.h> #include <fcall.h> #include <thread.h> #include <9p.h> #include "dat.h" #include "fns.h" static Xfs *xhead; static Xfile *freelist; static Lock xlock, freelock; int client; Xfs * getxfs(char *name) { int fd; Dir *dir; Xfs *xf, *fxf; if(name==0 || name[0]==0) name = deffile; if(name == 0){ errno = Enofilsys; return 0; } fd = open(name, rdonly ? OREAD : ORDWR); if(fd < 0){ errno = Enonexist; return 0; } if((dir = dirfstat(fd)) == 0){ errno = Eio; close(fd); return 0; } lock(&xlock); for(fxf=0, xf=xhead; xf; xf=xf->next){ if(xf->ref == 0){ if(fxf == 0) fxf = xf; continue; } if(xf->qid.path != dir->qid.path || xf->qid.vers != dir->qid.vers) continue; if(strcmp(xf->name, name) != 0 || xf->dev < 0) continue; chat("incref \"%s\", dev=%d...", xf->name, xf->dev); ++xf->ref; unlock(&xlock); close(fd); free(dir); return xf; } if(fxf==0){ fxf = malloc(sizeof(Xfs)); if(fxf==0){ unlock(&xlock); close(fd); free(dir); errno = Enomem; return 0; } fxf->next = xhead; xhead = fxf; } chat("alloc \"%s\", dev=%d...", name, fd); fxf->name = strdup(name); fxf->ref = 1; fxf->qid = dir->qid; fxf->dev = fd; fxf->fmt = 0; fxf->ptr = 0; free(dir); if( ext2fs(fxf)<0 ){ xhead = fxf->next; free(fxf); unlock(&xlock); return 0; } unlock(&xlock); return fxf; } void refxfs(Xfs *xf, int delta) { lock(&xlock); xf->ref += delta; if(xf->ref == 0){ /*mchat("free \"%s\", dev=%d...", xf->name, xf->dev); dumpbuf();*/ CleanSuper(xf); syncbuf(); free(xf->name); purgebuf(xf); if(xf->dev >= 0){ close(xf->dev); xf->dev = -1; } } unlock(&xlock); } Xfile * xfile(Fid *fid, int flag) { Xfile *f; f = (Xfile*)fid->aux; switch(flag){ default: panic("xfile"); case Asis: return (f && f->xf && f->xf->dev < 0) ? 0 : f; case Clean: if (f) chat("Clean and fid->aux already exists\n"); break; case Clunk: if(f){ clean(f); lock(&freelock); f->next = freelist; freelist = f; unlock(&freelock); fid->aux = 0; } return 0; } if(f) return clean(f); lock(&freelock); if(f = freelist){ /* assign = */ freelist = f->next; unlock(&freelock); } else { unlock(&freelock); f = malloc(sizeof(Xfile)); } fid->aux = f; f->fid = fid->fid; f->client = client; f->xf = 0; f->ptr = 0; f->root = 0; return f; } Xfile * clean(Xfile *f) { if(f->xf && f->root){ refxfs(f->xf, -1); f->xf = 0; } f->xf = 0; f->root = 0; f->dirindex = 0; return f; }