diff options
Diffstat (limited to 'sys/fs/unionfs/union_vfsops.c')
| -rw-r--r-- | sys/fs/unionfs/union_vfsops.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/sys/fs/unionfs/union_vfsops.c b/sys/fs/unionfs/union_vfsops.c index ae95bd9c005c..bd264c7bcdb5 100644 --- a/sys/fs/unionfs/union_vfsops.c +++ b/sys/fs/unionfs/union_vfsops.c @@ -371,16 +371,38 @@ unionfs_root(struct mount *mp, int flags, struct vnode **vpp) } static int -unionfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg) +unionfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg, + bool *mp_busy) { + struct mount *uppermp; struct unionfs_mount *ump; + int error; + bool unbusy; ump = MOUNTTOUNIONFSMOUNT(mp); - + uppermp = atomic_load_ptr(&ump->um_uppervp->v_mount); + KASSERT(*mp_busy == true, ("upper mount not busy")); + /* + * See comment in sys_quotactl() for an explanation of why the + * lower mount needs to be busied by the caller of VFS_QUOTACTL() + * but may be unbusied by the implementation. We must unbusy + * the upper mount for the same reason; otherwise a namei lookup + * issued by the VFS_QUOTACTL() implementation could traverse the + * upper mount and deadlock. + */ + vfs_unbusy(mp); + *mp_busy = false; + unbusy = true; + error = vfs_busy(uppermp, 0); /* * Writing is always performed to upper vnode. */ - return (VFS_QUOTACTL(ump->um_uppervp->v_mount, cmd, uid, arg)); + if (error == 0) + error = VFS_QUOTACTL(uppermp, cmd, uid, arg, &unbusy); + if (unbusy) + vfs_unbusy(uppermp); + + return (error); } static int |