dodup3() is already calling FREF(), just before a sleeping point. Diff
below moves it right after fd_getfile() to prepare for unlocking some
syscalls.
Ok?
Index: kern/kern_descrip.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_descrip.c,v
retrieving revision 1.143
diff -u -p -r1.143 kern_descrip.c
--- kern/kern_descrip.c 28 Mar 2018 09:49:28 -0000 1.143
+++ kern/kern_descrip.c 2 Apr 2018 10:51:51 -0000
@@ -289,9 +289,12 @@ dodup3(struct proc *p, int old, int new,
restart:
if ((fp = fd_getfile(fdp, old)) == NULL)
return (EBADF);
+ FREF(fp);
if ((u_int)new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
- (u_int)new >= maxfiles)
+ (u_int)new >= maxfiles) {
+ FRELE(fp, p);
return (EBADF);
+ }
if (old == new) {
/*
* NOTE! This doesn't clear the close-on-exec flag. This might
@@ -299,9 +302,9 @@ restart:
* this is what everyone else does.
*/
*retval = new;
+ FRELE(fp, p);
return (0);
}
- FREF(fp);
fdplock(fdp);
if (new >= fdp->fd_nfiles) {
if ((error = fdalloc(p, new, &i)) != 0) {
