Changeset View
Changeset View
Standalone View
Standalone View
sys/fs/unionfs/union_vfsops.c
| Show First 20 Lines • Show All 304 Lines • ▼ Show 20 Lines | if (lowermp != NULL) | ||||
| vfs_unregister_upper(lowermp, &ump->um_lower_link); | vfs_unregister_upper(lowermp, &ump->um_lower_link); | ||||
| if (uppermp != NULL) | if (uppermp != NULL) | ||||
| vfs_unregister_upper(uppermp, &ump->um_upper_link); | vfs_unregister_upper(uppermp, &ump->um_upper_link); | ||||
| free(ump, M_UNIONFSMNT); | free(ump, M_UNIONFSMNT); | ||||
| mp->mnt_data = NULL; | mp->mnt_data = NULL; | ||||
| return (ENOENT); | return (ENOENT); | ||||
| } | } | ||||
| /* | |||||
| * Specify that the covered vnode lock should remain held while | |||||
| * lookup() performs the cross-mount walk. This prevents a lock-order | |||||
| * reversal between the covered vnode lock (which is also locked by | |||||
| * unionfs_lock()) and the mountpoint's busy count. Without this, | |||||
| * unmount will lock the covered vnode lock (directly through the | |||||
| * covered vnode) and wait for the busy count to drain, while a | |||||
| * concurrent lookup will increment the busy count and then lock | |||||
| * the covered vnode lock (indirectly through unionfs_lock()). | |||||
| * | |||||
| * Note that we can't yet use this facility for the 'below' case | |||||
| * in which the upper vnode is the covered vnode, because that would | |||||
| * introduce a different LOR in which the cross-mount lookup would | |||||
| * effectively hold the upper vnode lock before acquiring the lower | |||||
| * vnode lock, while an unrelated lock operation would still acquire | |||||
| * the lower vnode lock before the upper vnode lock, which is the | |||||
| * order unionfs currently requires. | |||||
| */ | |||||
| if (!below) { | |||||
| vn_lock(mp->mnt_vnodecovered, LK_EXCLUSIVE | LK_RETRY); | |||||
| mp->mnt_vnodecovered->v_vflag |= VV_CROSSLOCK; | |||||
| VOP_UNLOCK(mp->mnt_vnodecovered); | |||||
| } | |||||
| MNT_ILOCK(mp); | MNT_ILOCK(mp); | ||||
| if ((lowermp->mnt_flag & MNT_LOCAL) != 0 && | if ((lowermp->mnt_flag & MNT_LOCAL) != 0 && | ||||
| (uppermp->mnt_flag & MNT_LOCAL) != 0) | (uppermp->mnt_flag & MNT_LOCAL) != 0) | ||||
| mp->mnt_flag |= MNT_LOCAL; | mp->mnt_flag |= MNT_LOCAL; | ||||
| mp->mnt_kern_flag |= MNTK_NOMSYNC | MNTK_UNIONFS; | mp->mnt_kern_flag |= MNTK_NOMSYNC | MNTK_UNIONFS; | ||||
| MNT_IUNLOCK(mp); | MNT_IUNLOCK(mp); | ||||
| /* | /* | ||||
| Show All 36 Lines | for (freeing = 0; (error = vflush(mp, 1, flags, curthread)) != 0;) { | ||||
| if (num == freeing) | if (num == freeing) | ||||
| break; | break; | ||||
| freeing = num; | freeing = num; | ||||
| } | } | ||||
| if (error) | if (error) | ||||
| return (error); | return (error); | ||||
| vn_lock(mp->mnt_vnodecovered, LK_EXCLUSIVE | LK_RETRY); | |||||
| mp->mnt_vnodecovered->v_vflag &= ~VV_CROSSLOCK; | |||||
| VOP_UNLOCK(mp->mnt_vnodecovered); | |||||
| vfs_unregister_upper(ump->um_lowervp->v_mount, &ump->um_lower_link); | vfs_unregister_upper(ump->um_lowervp->v_mount, &ump->um_lower_link); | ||||
| vfs_unregister_upper(ump->um_uppervp->v_mount, &ump->um_upper_link); | vfs_unregister_upper(ump->um_uppervp->v_mount, &ump->um_upper_link); | ||||
| free(ump, M_UNIONFSMNT); | free(ump, M_UNIONFSMNT); | ||||
| mp->mnt_data = NULL; | mp->mnt_data = NULL; | ||||
| return (0); | return (0); | ||||
| } | } | ||||
| ▲ Show 20 Lines • Show All 174 Lines • Show Last 20 Lines | |||||