Extract the code to put a filesystem into the suspended state (at the

unmount time) in the helper vfs_write_suspend_umnt().  Use it instead
of two inline copies in FFS.

Fix the bug in the FFS unmount, when suspension failed, the ufs
extattrs were not reinitialized.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks

3 files changed, 39 insertions, 44 deletions

diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index e7e0f9ecde29..f1d19acbca04 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -1830,6 +1830,37 @@ vfs_write_resume(struct mount *mp, int flags)
 }
 
 /*
+ * Helper loop around vfs_write_suspend() for filesystem unmount VFS
+ * methods.
+ */
+int
+vfs_write_suspend_umnt(struct mount *mp)
+{
+	int error;
+
+	KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
+	    ("vfs_write_suspend_umnt: recursed"));
+
+	/* dounmount() already called vn_start_write(). */
+	for (;;) {
+		vn_finished_write(mp);
+		error = vfs_write_suspend(mp, 0);
+		if (error != 0)
+			return (error);
+		MNT_ILOCK(mp);
+		if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
+			break;
+		MNT_IUNLOCK(mp);
+		vn_start_write(NULL, &mp, V_WAIT);
+	}
+	mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
+	wakeup(&mp->mnt_flag);
+	MNT_IUNLOCK(mp);
+	curthread->td_pflags |= TDP_IGNSUSP;
+	return (0);
+}
+
+/*
  * Implement kqueues for files by translating it to vnode operation.
  */
 static int
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index ee458217d5e1..2bc4a46165ea 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -721,6 +721,7 @@ int	vfs_cache_lookup(struct vop_lookup_args *ap);
 void	vfs_timestamp(struct timespec *);
 void	vfs_write_resume(struct mount *mp, int flags);
 int	vfs_write_suspend(struct mount *mp, int flags);
+int	vfs_write_suspend_umnt(struct mount *mp);
 int	vop_stdbmap(struct vop_bmap_args *);
 int	vop_stdfsync(struct vop_fsync_args *);
 int	vop_stdgetwritemount(struct vop_getwritemount_args *);
diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 40b335e4ad4d..576dd873517b 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -255,31 +255,9 @@ ffs_mount(struct mount *mp)
 			 */
 			if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0)
 				return (error);
-			for (;;) {
-				vn_finished_write(mp);
-				if ((error = vfs_write_suspend(mp, 0)) != 0)
-					return (error);
-				MNT_ILOCK(mp);
-				if (mp->mnt_kern_flag & MNTK_SUSPENDED) {
-					/*
-					 * Allow the secondary writes
-					 * to proceed.
-					 */
-					mp->mnt_kern_flag &= ~(MNTK_SUSPENDED |
-					    MNTK_SUSPEND2);
-					wakeup(&mp->mnt_flag);
-					MNT_IUNLOCK(mp);
-					/*
-					 * Allow the curthread to
-					 * ignore the suspension to
-					 * synchronize on-disk state.
-					 */
-					td->td_pflags |= TDP_IGNSUSP;
-					break;
-				}
-				MNT_IUNLOCK(mp);
-				vn_start_write(NULL, &mp, V_WAIT);
-			}
+			error = vfs_write_suspend_umnt(mp);
+			if (error != 0)
+				return (error);
 			/*
 			 * Check for and optionally get rid of files open
 			 * for writing.
@@ -1250,25 +1228,9 @@ ffs_unmount(mp, mntflags)
 	}
 #endif
 	if (susp) {
-		/*
-		 * dounmount already called vn_start_write().
-		 */
-		for (;;) {
-			vn_finished_write(mp);
-			if ((error = vfs_write_suspend(mp, 0)) != 0)
-				return (error);
-			MNT_ILOCK(mp);
-			if (mp->mnt_kern_flag & MNTK_SUSPENDED) {
-				mp->mnt_kern_flag &= ~(MNTK_SUSPENDED |
-				    MNTK_SUSPEND2);
-				wakeup(&mp->mnt_flag);
-				MNT_IUNLOCK(mp);
-				td->td_pflags |= TDP_IGNSUSP;
-				break;
-			}
-			MNT_IUNLOCK(mp);
-			vn_start_write(NULL, &mp, V_WAIT);
-		}
+		error = vfs_write_suspend_umnt(mp);
+		if (error != 0)
+			goto fail1;
 	}
 	if (MOUNTEDSOFTDEP(mp))
 		error = softdep_flushfiles(mp, flags, td);
@@ -1331,6 +1293,7 @@ ffs_unmount(mp, mntflags)
 fail:
 	if (susp)
 		vfs_write_resume(mp, VR_START_WRITE);
+fail1:
 #ifdef UFS_EXTATTR
 	if (e_restart) {
 		ufs_extattr_uepm_init(&ump->um_extattr);