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/ufs/pager.c b/ufs/pager.c
index 1e3d140c..5d3e44ab 100644
--- a/ufs/pager.c
+++ b/ufs/pager.c
@@ -450,6 +450,13 @@ pager_unlock_page (struct user_pager_info *pager,
   return err;
 }
 
+void
+pager_notify_evict (struct user_pager_info *pager,
+		    vm_offset_t page)
+{
+  assert (!"unrequested notification on eviction");
+}
+
 /* Implement the pager_report_extent callback from the pager library.  See
    <hurd/pager.h> for the interface description. */
 inline error_t
@@ -502,7 +509,7 @@ create_disk_pager (void)
   upi->type = DISK;
   upi->np = 0;
   pager_bucket = ports_create_bucket ();
-  diskfs_start_disk_pager (upi, pager_bucket, MAY_CACHE, store->size,
+  diskfs_start_disk_pager (upi, pager_bucket, MAY_CACHE, 0, store->size,
 			   &disk_image);
   upi->p = diskfs_disk_pager;
 }
@@ -595,7 +602,7 @@ diskfs_get_filemap (struct node *np, vm_prot_t prot)
 	upi->unlocked_pagein_length = 0;
 	diskfs_nref_light (np);
 	upi->p = pager_create (upi, pager_bucket,
-			       MAY_CACHE, MEMORY_OBJECT_COPY_DELAY);
+			       MAY_CACHE, MEMORY_OBJECT_COPY_DELAY, 0);
 	if (upi->p == 0)
 	  {
 	    diskfs_nrele_light (np);