svn commit: r351475 - in stable/12/sys: fs/tmpfs kern sys

[Konstantin Belousov]

Author: kib
Date: Sun Aug 25 06:22:13 2019
New Revision: 351475
URL: https://svnweb.freebsd.org/changeset/base/351475

Log:
  MFC r351195:
  Fix an issue with executing tmpfs binary.

Modified:
  stable/12/sys/fs/tmpfs/tmpfs_vfsops.c
  stable/12/sys/kern/vfs_default.c
  stable/12/sys/sys/mount.h
  stable/12/sys/sys/vnode.h
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/fs/tmpfs/tmpfs_vfsops.c
==============================================================================
--- stable/12/sys/fs/tmpfs/tmpfs_vfsops.c	Sun Aug 25 06:19:51 2019	(r351474)
+++ stable/12/sys/fs/tmpfs/tmpfs_vfsops.c	Sun Aug 25 06:22:13 2019	(r351475)
@@ -504,7 +504,8 @@ tmpfs_mount(struct mount *mp)
 
 	MNT_ILOCK(mp);
 	mp->mnt_flag |= MNT_LOCAL;
-	mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED;
+	mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED |
+	    MNTK_TEXT_REFS;
 	MNT_IUNLOCK(mp);
 
 	mp->mnt_data = tmp;

Modified: stable/12/sys/kern/vfs_default.c
==============================================================================
--- stable/12/sys/kern/vfs_default.c	Sun Aug 25 06:19:51 2019	(r351474)
+++ stable/12/sys/kern/vfs_default.c	Sun Aug 25 06:22:13 2019	(r351475)
@@ -1068,6 +1068,7 @@ int
 vop_stdset_text(struct vop_set_text_args *ap)
 {
 	struct vnode *vp;
+	struct mount *mp;
 	int error;
 
 	vp = ap->a_vp;
@@ -1075,6 +1076,17 @@ vop_stdset_text(struct vop_set_text_args *ap)
 	if (vp->v_writecount > 0) {
 		error = ETXTBSY;
 	} else {
+		/*
+		 * If requested by fs, keep a use reference to the
+		 * vnode until the last text reference is released.
+		 */
+		mp = vp->v_mount;
+		if (mp != NULL && (mp->mnt_kern_flag & MNTK_TEXT_REFS) != 0 &&
+		    vp->v_writecount == 0) {
+			vp->v_iflag |= VI_TEXT_REF;
+			vrefl(vp);
+		}
+
 		vp->v_writecount--;
 		error = 0;
 	}
@@ -1087,16 +1099,25 @@ vop_stdunset_text(struct vop_unset_text_args *ap)
 {
 	struct vnode *vp;
 	int error;
+	bool last;
 
 	vp = ap->a_vp;
+	last = false;
 	VI_LOCK(vp);
 	if (vp->v_writecount < 0) {
+		if ((vp->v_iflag & VI_TEXT_REF) != 0 &&
+		    vp->v_writecount == -1) {
+			last = true;
+			vp->v_iflag &= ~VI_TEXT_REF;
+		}
 		vp->v_writecount++;
 		error = 0;
 	} else {
 		error = EINVAL;
 	}
 	VI_UNLOCK(vp);
+	if (last)
+		vunref(vp);
 	return (error);
 }
 

Modified: stable/12/sys/sys/mount.h
==============================================================================
--- stable/12/sys/sys/mount.h	Sun Aug 25 06:19:51 2019	(r351474)
+++ stable/12/sys/sys/mount.h	Sun Aug 25 06:22:13 2019	(r351475)
@@ -398,6 +398,7 @@ void          __mnt_vnode_markerfree_active(struct vno
 #define	MNTK_MARKER		0x00001000
 #define	MNTK_UNMAPPED_BUFS	0x00002000
 #define	MNTK_USES_BCACHE	0x00004000 /* FS uses the buffer cache. */
+#define	MNTK_TEXT_REFS		0x00008000 /* Keep use ref for text */
 #define MNTK_NOASYNC	0x00800000	/* disable async */
 #define MNTK_UNMOUNT	0x01000000	/* unmount in progress */
 #define	MNTK_MWAIT	0x02000000	/* waiting for unmount to finish */

Modified: stable/12/sys/sys/vnode.h
==============================================================================
--- stable/12/sys/sys/vnode.h	Sun Aug 25 06:19:51 2019	(r351474)
+++ stable/12/sys/sys/vnode.h	Sun Aug 25 06:22:13 2019	(r351475)
@@ -233,6 +233,7 @@ struct xvnode {
  *	VI_DOOMED is doubly protected by the interlock and vnode lock.  Both
  *	are required for writing but the status may be checked with either.
  */
+#define	VI_TEXT_REF	0x0001	/* Text ref grabbed use ref */
 #define	VI_MOUNT	0x0020	/* Mount in progress */
 #define	VI_DOOMED	0x0080	/* This vnode is being recycled */
 #define	VI_FREE		0x0100	/* This vnode is on the freelist */