xnu-2782.1.97.tar.gz

[apple/xnu.git] / bsd / vm / dp_backing_file.c

diff --git a/bsd/vm/dp_backing_file.c b/bsd/vm/dp_backing_file.c
index cc52be8fb750fd8cf2c12a8566f0f3c895e0b79f..31b87e8a0caa7cea44c6fee8a3fd3ce1b42a91c9 100644 (file)
--- a/bsd/vm/dp_backing_file.c
+++ b/bsd/vm/dp_backing_file.c
@@ -60,6 +60,7 @@
 #include <mach/boolean.h>
 
 #include <kern/kern_types.h>
+#include <kern/locks.h>
 #include <kern/host.h>
 #include <kern/task.h>
 #include <kern/zalloc.h>
@@ -77,7 +78,12 @@
 #include <security/mac_framework.h>
 #endif
 
-void kprintf(const char *fmt, ...);
+#include <pexpert/pexpert.h>
+
+void macx_init(void);
+
+static lck_grp_t *macx_lock_group;
+static lck_mtx_t *macx_lock;
 
 /*
  * temporary support for delayed instantiation
@@ -99,6 +105,18 @@ struct bs_map               bs_port_table[MAX_BACKING_STORE] = {
 
 /* ###################################################### */
 
+/*
+ *     Routine:        macx_init
+ *     Function:
+ *             Initialize locks so that only one caller can change
+ *      state at a time.
+ */
+void
+macx_init(void)
+{
+       macx_lock_group = lck_grp_alloc_init("macx", NULL);
+       macx_lock = lck_mtx_alloc_init(macx_lock_group, NULL);
+}
 
 /*
  *     Routine:        macx_backing_store_recovery
@@ -114,9 +132,7 @@ macx_backing_store_recovery(
        int             pid = args->pid;
        int             error;
        struct proc     *p =  current_proc();
-       boolean_t       funnel_state;
 
-       funnel_state = thread_funnel_set(kernel_flock, TRUE);
        if ((error = suser(kauth_cred_get(), 0)))
                goto backing_store_recovery_return;
 
@@ -130,7 +146,6 @@ macx_backing_store_recovery(
        task_backing_store_privileged(p->task);
 
 backing_store_recovery_return:
-       (void) thread_funnel_set(kernel_flock, FALSE);
        return(error);
 }
 
@@ -147,16 +162,16 @@ macx_backing_store_suspend(
 {
        boolean_t       suspend = args->suspend;
        int             error;
-       boolean_t       funnel_state;
 
-       funnel_state = thread_funnel_set(kernel_flock, TRUE);
+       lck_mtx_lock(macx_lock);
        if ((error = suser(kauth_cred_get(), 0)))
                goto backing_store_suspend_return;
 
+       /* Multiple writers protected by macx_lock */
        vm_backing_store_disable(suspend);
 
 backing_store_suspend_return:
-       (void) thread_funnel_set(kernel_flock, FALSE);
+       lck_mtx_unlock(macx_lock);
        return(error);
 }
 
@@ -173,6 +188,9 @@ extern boolean_t compressor_store_stop_compaction;
  *             on by default when the system comes up and is turned 
  *             off when a shutdown/restart is requested.  It is 
  *             re-enabled if the shutdown/restart is aborted for any reason.
+ *
+ *  This routine assumes macx_lock has been locked by macx_triggers ->
+ *      mach_macx_triggers -> macx_backing_store_compaction
  */
 
 int
@@ -180,6 +198,7 @@ macx_backing_store_compaction(int flags)
 {
        int error;
 
+       lck_mtx_assert(macx_lock, LCK_MTX_ASSERT_OWNED);
        if ((error = suser(kauth_cred_get(), 0)))
                return error;
 
@@ -211,17 +230,19 @@ macx_triggers(
 {
        int     error;
 
+       lck_mtx_lock(macx_lock);
        error = suser(kauth_cred_get(), 0);
        if (error)
                return error;
 
-       return mach_macx_triggers(args);
+       error = mach_macx_triggers(args);
+       
+       lck_mtx_unlock(macx_lock);
+       return error;
 }
 
 
 extern boolean_t dp_isssd;
-extern void vm_swap_init(void);
-extern int vm_compressor_mode;
 
 /*
  * In the compressed pager world, the swapfiles are created by the kernel.
@@ -265,30 +286,27 @@ macx_swapon(
        mach_port_t             backing_store;
        memory_object_default_t default_pager;
        int                     i;
-       boolean_t               funnel_state;
        off_t                   file_size;
        vfs_context_t           ctx = vfs_context_current();
        struct proc             *p =  current_proc();
        int                     dp_cluster_size;
 
+       AUDIT_MACH_SYSCALL_ENTER(AUE_SWAPON);
+       AUDIT_ARG(value32, args->priority);
+       
+       lck_mtx_lock(macx_lock);
+
        if (COMPRESSED_PAGER_IS_ACTIVE) {
                if (macx_swapon_allowed == FALSE) {
-                       return EINVAL;
+                       error = EINVAL;
+                       goto swapon_bailout;
                } else {
-                       if ((vm_compressor_mode == VM_PAGER_COMPRESSOR_WITH_SWAP) ||
-                           (vm_compressor_mode == VM_PAGER_FREEZER_COMPRESSOR_WITH_SWAP)) {
-                               vm_swap_init();
-                       }
-
                        macx_swapon_allowed = FALSE;
-                       return 0;
+                       error = 0;
+                       goto swapon_bailout;
                }
        }
 
-       AUDIT_MACH_SYSCALL_ENTER(AUE_SWAPON);
-       AUDIT_ARG(value32, args->priority);
-
-       funnel_state = thread_funnel_set(kernel_flock, TRUE);
        ndp = &nd;
 
        if ((error = suser(kauth_cred_get(), 0)))
@@ -437,7 +455,7 @@ swapon_bailout:
        if (vp) {
                vnode_put(vp);
        }
-       (void) thread_funnel_set(kernel_flock, FALSE);
+       lck_mtx_unlock(macx_lock);
        AUDIT_MACH_SYSCALL_EXIT(error);
 
        if (error)
@@ -466,13 +484,13 @@ macx_swapoff(
        struct proc             *p =  current_proc();
        int                     i;
        int                     error;
-       boolean_t               funnel_state;
        vfs_context_t ctx = vfs_context_current();
        int                     orig_iopol_disk;
 
        AUDIT_MACH_SYSCALL_ENTER(AUE_SWAPOFF);
 
-       funnel_state = thread_funnel_set(kernel_flock, TRUE);
+       lck_mtx_lock(macx_lock);
+       
        backing_store = NULL;
        ndp = &nd;
 
@@ -550,8 +568,7 @@ swapoff_bailout:
        /* get rid of macx_swapoff() namei() reference */
        if (vp)
                vnode_put(vp);
-
-       (void) thread_funnel_set(kernel_flock, FALSE);
+       lck_mtx_unlock(macx_lock);
        AUDIT_MACH_SYSCALL_EXIT(error);
 
        if (error)
@@ -591,7 +608,7 @@ macx_swapinfo(
 
                        *total_p = vm_swap_get_total_space();
                        *avail_p = vm_swap_get_free_space();
-                       *pagesize_p = PAGE_SIZE_64;
+                       *pagesize_p = (vm_size_t)PAGE_SIZE_64;
                        *encrypted_p = TRUE;
 
                } else {