Push down Giant into fdfree() and remove it from two of the callers.

Other callers such as some rfork() cases weren't locking Giant anyway.

Reviewed by:	csjp
MFC after:	1 week

3 files changed, 24 insertions, 13 deletions

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 5bf1553..eae5b99 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -1525,10 +1525,10 @@ fdfree(struct thread *td)
 {
 	struct filedesc *fdp;
 	struct file **fpp;
-	int i;
+	int i, locked;
 	struct filedesc_to_leader *fdtol;
 	struct file *fp;
-	struct vnode *vp;
+	struct vnode *cdir, *jdir, *rdir, *vp;
 	struct flock lf;
 
 	/* Certain daemons might not have file descriptors. */
@@ -1559,13 +1559,14 @@ fdfree(struct thread *td)
 				lf.l_len = 0;
 				lf.l_type = F_UNLCK;
 				vp = fp->f_vnode;
-				VFS_ASSERT_GIANT(vp->v_mount);
+				locked = VFS_LOCK_GIANT(vp->v_mount);
 				(void) VOP_ADVLOCK(vp,
 						   (caddr_t)td->td_proc->
 						   p_leader,
 						   F_UNLCK,
 						   &lf,
 						   F_POSIX);
+				VFS_UNLOCK_GIANT(locked);
 				FILEDESC_LOCK(fdp);
 				fdrop(fp, td);
 				fpp = fdp->fd_ofiles + i;
@@ -1635,18 +1636,30 @@ fdfree(struct thread *td)
 
 	fdp->fd_nfiles = 0;
 
-	if (fdp->fd_cdir)
-		vrele(fdp->fd_cdir);
+	cdir = fdp->fd_cdir;
 	fdp->fd_cdir = NULL;
-	if (fdp->fd_rdir)
-		vrele(fdp->fd_rdir);
+	rdir = fdp->fd_rdir;
 	fdp->fd_rdir = NULL;
-	if (fdp->fd_jdir)
-		vrele(fdp->fd_jdir);
+	jdir = fdp->fd_jdir;
 	fdp->fd_jdir = NULL;
-
 	FILEDESC_UNLOCK(fdp);
 
+	if (cdir) {
+		locked = VFS_LOCK_GIANT(cdir->v_mount);
+		vrele(cdir);
+		VFS_UNLOCK_GIANT(locked);
+	}
+	if (rdir) {
+		locked = VFS_LOCK_GIANT(rdir->v_mount);
+		vrele(rdir);
+		VFS_UNLOCK_GIANT(locked);
+	}
+	if (jdir) {
+		locked = VFS_LOCK_GIANT(jdir->v_mount);
+		vrele(jdir);
+		VFS_UNLOCK_GIANT(locked);
+	}
+
 	fddrop(fdp);
 }
 
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index 25ca5b8..6107a00 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -235,6 +235,7 @@ retry:
 	 */
 	mtx_lock(&Giant);	/* XXX: not sure if needed */
 	funsetownlst(&p->p_sigiolst);
+	mtx_unlock(&Giant);	
 
 	/*
 	 * If this process has an nlminfo data area (for lockd), release it
@@ -247,7 +248,6 @@ retry:
 	 * This may block!
 	 */
 	fdfree(td);
-	mtx_unlock(&Giant);	
 
 	/*
 	 * If this thread tickled GEOM, we need to wait for the giggling to
diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
index 007d1ed..b39f1a6 100644
--- a/sys/kern/vfs_aio.c
+++ b/sys/kern/vfs_aio.c
@@ -894,10 +894,8 @@ aio_daemon(void *uproc)
 	 * Get rid of our current filedescriptors.  AIOD's don't need any
 	 * filedescriptors, except as temporarily inherited from the client.
 	 */
-	mtx_lock(&Giant);
 	fdfree(td);
 
-	mtx_unlock(&Giant);
 	/* The daemon resides in its own pgrp. */
 	MALLOC(newpgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
 		M_WAITOK | M_ZERO);