When attempt is made to suspend a filesystem that is already syspended,

wait until the current suspension is lifted instead of silently returning
success immediately. The consequences of calling vfs_write() resume when
not owning the suspension are not well-defined at best.

Add the vfs_susp_clean() mount method to be called from
vfs_write_resume(). Set it to process_deferred_inactive() for ffs, and
stop calling it manually.

Add the thread flag TDP_IGNSUSP that allows to bypass the suspension
point in the vn_start_write. It is intended for use by VFS in the
situations where the suspender want to do some i/o requiring calls to
vn_start_write(), and this i/o cannot be done later.

Reviewed by:	tegge
In collaboration with:	pho
MFC after:	 1 month

1 files changed, 1 insertions, 0 deletions

diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 93e0b48..86b3f60 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -105,6 +105,7 @@ static struct vfsops ufs_vfsops = {
 	.vfs_uninit =		ffs_uninit,
 	.vfs_unmount =		ffs_unmount,
 	.vfs_vget =		ffs_vget,
+	.vfs_susp_clean =	process_deferred_inactive,
 };
 
 VFS_SET(ufs_vfsops, ufs, 0);