postpone memory allocation for uvm swap encryption until it is turned on with

sysctl.

3 files changed, 57 insertions, 12 deletions

diff --git a/sys/uvm/uvm_meter.c b/sys/uvm/uvm_meter.c
index 3c287ca34e5..da160cf64e3 100644
--- a/sys/uvm/uvm_meter.c
+++ b/sys/uvm/uvm_meter.c
@@ -49,6 +49,7 @@
 #include <sys/exec.h>
 
 #ifdef UVM_SWAP_ENCRYPT
+#include <uvm/uvm_swap.h>
 #include <uvm/uvm_swap_encrypt.h>
 #endif
 
@@ -153,9 +154,23 @@ uvm_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
 		return (sysctl_rdstruct(oldp, oldlenp, newp, &_ps,
 		    sizeof(_ps)));
 #ifdef UVM_SWAP_ENCRYPT
-	case VM_SWAPENCRYPT:
-		return (sysctl_int(oldp, oldlenp, newp, newlen,
-		    &uvm_doswapencrypt));
+	case VM_SWAPENCRYPT: {
+		int doencrypt = uvm_doswapencrypt;
+		int result;
+
+		result = sysctl_int(oldp, oldlenp, newp, newlen, &doencrypt);
+		if (result)
+			return result;
+
+		/* Swap Encryption has been turned on, we need to
+		 * initalize state for swap devices that have been
+		 * added 
+		 */
+		if (doencrypt)
+			uvm_swap_initcrypt_all();
+		uvm_doswapencrypt = doencrypt;
+		return (0);
+	}
 #endif
 	default:
 		return (EOPNOTSUPP);
diff --git a/sys/uvm/uvm_swap.c b/sys/uvm/uvm_swap.c
index 21f73ef23fe..c00ccc2db9a 100644
--- a/sys/uvm/uvm_swap.c
+++ b/sys/uvm/uvm_swap.c
@@ -282,6 +282,7 @@ boolean_t uvm_swap_allocpages __P((struct vm_page **, int));
 void uvm_swap_freepages __P((struct vm_page **, int));
 void uvm_swap_markdecrypt __P((struct swapdev *, int, int, int));
 boolean_t uvm_swap_needdecrypt __P((struct swapdev *, int));
+void uvm_swap_initcrypt __P((struct swapdev *, int));
 #endif
 
 /*
@@ -358,6 +359,39 @@ uvm_swap_init()
 }
 
 #ifdef UVM_SWAP_ENCRYPT
+void
+uvm_swap_initcrypt_all(void)
+{
+	struct swapdev *sdp;
+	struct swappri *spp;
+
+	simple_lock(&uvm.swap_data_lock);
+
+	for (spp = swap_priority.lh_first; spp != NULL;
+	     spp = spp->spi_swappri.le_next) {
+		for (sdp = spp->spi_swapdev.cqh_first;
+		     sdp != (void *)&spp->spi_swapdev;
+		     sdp = sdp->swd_next.cqe_next)
+			if (sdp->swd_decrypt == NULL)
+				uvm_swap_initcrypt(sdp, sdp->swd_npages);
+	}
+	simple_unlock(&uvm.swap_data_lock);
+}
+
+void
+uvm_swap_initcrypt(struct swapdev *sdp, int npages)
+{
+	/*
+	 * keep information if a page needs to be decrypted when we get it
+	 * from the swap device.
+	 * We cannot chance a malloc later, if we are doing ASYNC puts,
+	 * we may not call malloc with M_WAITOK.  This consumes only
+	 * 8KB memory for a 256MB swap partition.
+	 */
+	sdp->swd_decrypt = malloc(SWD_DCRYPT_SIZE(npages), M_VMSWAP, M_WAITOK);
+	bzero(sdp->swd_decrypt, SWD_DCRYPT_SIZE(npages));
+}
+
 boolean_t
 uvm_swap_allocpages(struct vm_page **pps, int npages)
 {
@@ -1109,15 +1143,8 @@ swap_on(p, sdp)
 	}
 
 #ifdef UVM_SWAP_ENCRYPT
-	/*
-	 * keep information if a page needs to be decrypted when we get it
-	 * from the swap device.
-	 * We cannot chance a malloc later, if we are doing ASYNC puts,
-	 * we may not call malloc with M_WAITOK.  This takes consumes only
-	 * 8KB memory for a 256MB swap partition.
-	 */
-	sdp->swd_decrypt = malloc(SWD_DCRYPT_SIZE(npages), M_VMSWAP, M_WAITOK);
-	bzero(sdp->swd_decrypt, SWD_DCRYPT_SIZE(npages));
+	if (uvm_doswapencrypt)
+		uvm_swap_initcrypt(sdp, npages);
 #endif
 	/*
 	 * now add the new swapdev to the drum and enable.
diff --git a/sys/uvm/uvm_swap.h b/sys/uvm/uvm_swap.h
index 008db98b241..42a6f4aa4e6 100644
--- a/sys/uvm/uvm_swap.h
+++ b/sys/uvm/uvm_swap.h
@@ -39,4 +39,7 @@ int			uvm_swap_put __P((int, struct vm_page **, int,
 int			uvm_swap_alloc __P((int *wanted, boolean_t lessok));
 void			uvm_swap_free __P((int startslot, int nslots));
 
+#ifdef UVM_SWAP_ENCRYPT
+void			uvm_swap_initcrypt_all __P((void));
+#endif
 #endif /* _UVM_UVM_SWAP_H_ */