From 5ffc99e2e4e63ee13bc99e337010716585df2332 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Mon, 8 Apr 2019 15:20:05 +0000 Subject: [PATCH] Handle races when remounting UFS volume from ro to rw. In particular, ensure that writers are not unleashed before SU structures are initialized. Also, correctly handle MNT_ASYNC before this. Reported and tested by: pho Reviewed by: mckusick Sponsored by: The FreeBSD Foundation MFC after: 1 week --- sys/ufs/ffs/ffs_vfsops.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c index 5af068cd7865..99f6ab514861 100644 --- a/sys/ufs/ffs/ffs_vfsops.c +++ b/sys/ufs/ffs/ffs_vfsops.c @@ -154,7 +154,7 @@ ffs_mount(struct mount *mp) struct fs *fs; pid_t fsckpid = 0; int error, error1, flags; - uint64_t mntorflags; + uint64_t mntorflags, saved_mnt_flag; accmode_t accmode; struct nameidata ndp; char *fspec; @@ -371,25 +371,40 @@ ffs_mount(struct mount *mp) return (error); if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0) return (error); + error = vfs_write_suspend_umnt(mp); + if (error != 0) + return (error); fs->fs_ronly = 0; MNT_ILOCK(mp); - mp->mnt_flag &= ~MNT_RDONLY; + saved_mnt_flag = MNT_RDONLY; + if (MOUNTEDSOFTDEP(mp) && (mp->mnt_flag & + MNT_ASYNC) != 0) + saved_mnt_flag |= MNT_ASYNC; + mp->mnt_flag &= ~saved_mnt_flag; MNT_IUNLOCK(mp); fs->fs_mtime = time_second; /* check to see if we need to start softdep */ if ((fs->fs_flags & FS_DOSOFTDEP) && (error = softdep_mount(devvp, mp, fs, td->td_ucred))){ - vn_finished_write(mp); + fs->fs_ronly = 1; + MNT_ILOCK(mp); + mp->mnt_flag |= saved_mnt_flag; + MNT_IUNLOCK(mp); + vfs_write_resume(mp, 0); return (error); } fs->fs_clean = 0; if ((error = ffs_sbupdate(ump, MNT_WAIT, 0)) != 0) { - vn_finished_write(mp); + fs->fs_ronly = 1; + MNT_ILOCK(mp); + mp->mnt_flag |= saved_mnt_flag; + MNT_IUNLOCK(mp); + vfs_write_resume(mp, 0); return (error); } if (fs->fs_snapinum[0] != 0) ffs_snapshot_mount(mp); - vn_finished_write(mp); + vfs_write_resume(mp, 0); } /* * Soft updates is incompatible with "async",