From ea31808c3b07eb7bdea0f8f552508ddf620f043f Mon Sep 17 00:00:00 2001
From: Mateusz Guzik <mjg@FreeBSD.org>
Date: Sun, 14 Jun 2015 14:08:52 +0000
Subject: [PATCH] fd: move out actual fp installation to _finstall

Use it in fd passing functions as the first step towards fd code cleanup.
---
 sys/kern/kern_descrip.c | 36 +++++++++++++++++++++++-------------
 sys/kern/uipc_usrreq.c  | 13 +++++--------
 sys/sys/filedesc.h      |  4 +++-
 3 files changed, 31 insertions(+), 22 deletions(-)

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index f6f819464f30..0ba507fe36fb 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -1750,26 +1750,18 @@ falloc_noinstall(struct thread *td, struct file **resultfp)
 /*
  * Install a file in a file descriptor table.
  */
-int
-finstall(struct thread *td, struct file *fp, int *fd, int flags,
+void
+_finstall(struct filedesc *fdp, struct file *fp, int fd, int flags,
     struct filecaps *fcaps)
 {
-	struct filedesc *fdp = td->td_proc->p_fd;
 	struct filedescent *fde;
-	int error;
 
-	KASSERT(fd != NULL, ("%s: fd == NULL", __func__));
-	KASSERT(fp != NULL, ("%s: fp == NULL", __func__));
+	MPASS(fp != NULL);
 	if (fcaps != NULL)
 		filecaps_validate(fcaps, __func__);
+	FILEDESC_XLOCK_ASSERT(fdp);
 
-	FILEDESC_XLOCK(fdp);
-	if ((error = fdalloc(td, 0, fd))) {
-		FILEDESC_XUNLOCK(fdp);
-		return (error);
-	}
-	fhold(fp);
-	fde = &fdp->fd_ofiles[*fd];
+	fde = &fdp->fd_ofiles[fd];
 #ifdef CAPABILITIES
 	seq_write_begin(&fde->fde_seq);
 #endif
@@ -1783,6 +1775,24 @@ finstall(struct thread *td, struct file *fp, int *fd, int flags,
 #ifdef CAPABILITIES
 	seq_write_end(&fde->fde_seq);
 #endif
+}
+
+int
+finstall(struct thread *td, struct file *fp, int *fd, int flags,
+    struct filecaps *fcaps)
+{
+	struct filedesc *fdp = td->td_proc->p_fd;
+	int error;
+
+	MPASS(fd != NULL);
+
+	FILEDESC_XLOCK(fdp);
+	if ((error = fdalloc(td, 0, fd))) {
+		FILEDESC_XUNLOCK(fdp);
+		return (error);
+	}
+	fhold(fp);
+	_finstall(fdp, fp, *fd, flags, fcaps);
 	FILEDESC_XUNLOCK(fdp);
 	return (0);
 }
diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c
index 808020e5e61d..acf9fe9bd1e0 100644
--- a/sys/kern/uipc_usrreq.c
+++ b/sys/kern/uipc_usrreq.c
@@ -1736,7 +1736,7 @@ unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
 	int i;
 	int *fdp;
 	struct filedesc *fdesc = td->td_proc->p_fd;
-	struct filedescent *fde, **fdep;
+	struct filedescent **fdep;
 	void *data;
 	socklen_t clen = control->m_len, datalen;
 	int error, newfds;
@@ -1795,13 +1795,10 @@ unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
 				goto next;
 			}
 			for (i = 0; i < newfds; i++, fdp++) {
-				fde = &fdesc->fd_ofiles[*fdp];
-				fde->fde_file = fdep[i]->fde_file;
-				filecaps_move(&fdep[i]->fde_caps,
-				    &fde->fde_caps);
-				if ((flags & MSG_CMSG_CLOEXEC) != 0)
-					fde->fde_flags |= UF_EXCLOSE;
-				unp_externalize_fp(fde->fde_file);
+				_finstall(fdesc, fdep[i]->fde_file, *fdp,
+				    (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0,
+				    &fdep[i]->fde_caps);
+				unp_externalize_fp(fdep[i]->fde_file);
 			}
 			FILEDESC_XUNLOCK(fdesc);
 			free(fdep[0], M_FILECAPS);
diff --git a/sys/sys/filedesc.h b/sys/sys/filedesc.h
index 3fe61c883cd7..da80ed95672b 100644
--- a/sys/sys/filedesc.h
+++ b/sys/sys/filedesc.h
@@ -147,7 +147,9 @@ int	dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
 int	falloc(struct thread *td, struct file **resultfp, int *resultfd,
 	    int flags);
 int	falloc_noinstall(struct thread *td, struct file **resultfp);
-int	finstall(struct thread *td, struct file *fp, int *resultfp, int flags,
+void	_finstall(struct filedesc *fdp, struct file *fp, int fd, int flags,
+	    struct filecaps *fcaps);
+int	finstall(struct thread *td, struct file *fp, int *resultfd, int flags,
 	    struct filecaps *fcaps);
 int	fdalloc(struct thread *td, int minfd, int *result);
 int	fdallocn(struct thread *td, int minfd, int *fds, int n);