Handle notification on page eviction

If requested by the user, make libpager call pager_notify_evict when a page
is flushed out by the kernel. Based on work by Ognyan Kulev.

* console/pager.c (pager_notify_evict): New function.
(user_pager_create): Update call to pager_create.
* ext2fs/pager.c: (pager_notify_evict): New function.
(create_disk_pager): Update call to diskfs_start_disk_pager.
(diskfs_get_filemap): Update call to pager_create.
* fatfs/pager.c: (pager_notify_evict): New function.
(create_fat_pager): Update call to diskfs_start_disk_pager.
(diskfs_get_filemap): Update call to pager_create.
* isofs/pager.c: (pager_notify_evict): New function.
(create_disk_pager): Update call to diskfs_start_disk_pager.
(diskfs_get_filemap): Update call to pager_create.
* libdiskfs/disk-pager.c (diskfs_start_disk_pager): Update definition and call
to pager_create.
* libdiskfs/diskfs-pager.h (diskfs_start_disk_pager): Update declaration.
* libpager/data-request.c (_pager_seqnos_memory_object_data_request): Take
pager's `notify_on_evict' member into account when calling
memory_object_data_supply.
* libpager/data-return.c (_pager_do_write_request): Handle user notification
on page flush.
* libpager/pager-create.c (pager_create): Update definition and set pager's
`notify_on_evict' member.
* libpager/pager.h (pager_create): Update declaration.
(pager_notify_evict): New declaration.
* libpager/priv.h (struct pager): New `notify_on_evict' member.
* storeio/pager.c: (pager_notify_evict): New function.
(dev_get_memory_object): Update call to pager_create.
* tmpfs/pager-stubs.c (pager_notify_evict): New function.
* ufs/pager.c (pager_notify_evict): New function.
(create_disk_pager): Update call to diskfs_start_disk_pager.
(diskfs_get_filemap): Update call to pager_create.

1 files changed, 9 insertions, 2 deletions

diff --git a/fatfs/pager.c b/fatfs/pager.c
index f892c88f..8146e648 100644
--- a/fatfs/pager.c
+++ b/fatfs/pager.c
@@ -596,6 +596,13 @@ pager_unlock_page (struct user_pager_info *pager,
   return 0;
 }
 
+void
+pager_notify_evict (struct user_pager_info *pager,
+		    vm_offset_t page)
+{
+  assert (!"unrequested notification on eviction");
+}
+
 /* Grow the disk allocated to locked node NODE to be at least SIZE
    bytes, and set NODE->allocsize to the actual allocated size.  (If
    the allocated size is already SIZE bytes, do nothing.)  CRED
@@ -752,7 +759,7 @@ create_fat_pager (void)
   struct user_pager_info *upi = malloc (sizeof (struct user_pager_info));
   upi->type = FAT;
   pager_bucket = ports_create_bucket ();
-  diskfs_start_disk_pager (upi, pager_bucket, MAY_CACHE,
+  diskfs_start_disk_pager (upi, pager_bucket, MAY_CACHE, 0,
 			   bytes_per_sector * sectors_per_fat,
 			   &fat_image);
 }
@@ -794,7 +801,7 @@ diskfs_get_filemap (struct node *node, vm_prot_t prot)
           diskfs_nref_light (node);
           node->dn->pager =
             pager_create (upi, pager_bucket, MAY_CACHE,
-                          MEMORY_OBJECT_COPY_DELAY);
+                          MEMORY_OBJECT_COPY_DELAY, 0);
           if (node->dn->pager == 0)
             {
               diskfs_nrele_light (node);