Fix zfsctl_expire_snapshot() deadlock

[zfs.git] / module / zfs / zfs_ctldir.c

diff --git a/module/zfs/zfs_ctldir.c b/module/zfs/zfs_ctldir.c
index 4fa530b..168f853 100644 (file)
--- a/module/zfs/zfs_ctldir.c
+++ b/module/zfs/zfs_ctldir.c
@@ -732,7 +732,11 @@ zfsctl_unmount_snapshot(zfs_sb_t *zsb, char *name, int flags)
        sep = avl_find(&zsb->z_ctldir_snaps, &search, NULL);
        if (sep) {
                avl_remove(&zsb->z_ctldir_snaps, sep);
+               mutex_exit(&zsb->z_ctldir_lock);
+
                error = __zfsctl_unmount_snapshot(sep, flags);
+
+               mutex_enter(&zsb->z_ctldir_lock);
                if (error == EBUSY)
                        avl_add(&zsb->z_ctldir_snaps, sep);
                else
@@ -767,7 +771,11 @@ zfsctl_unmount_snapshots(zfs_sb_t *zsb, int flags, int *count)
        while (sep != NULL) {
                next = AVL_NEXT(&zsb->z_ctldir_snaps, sep);
                avl_remove(&zsb->z_ctldir_snaps, sep);
+               mutex_exit(&zsb->z_ctldir_lock);
+
                error = __zfsctl_unmount_snapshot(sep, flags);
+
+               mutex_enter(&zsb->z_ctldir_lock);
                if (error == EBUSY) {
                        avl_add(&zsb->z_ctldir_snaps, sep);
                        (*count)++;