Finalize GETPAGES layering scheme. Move the device GETPAGES

interface into specfs code.  No need at this point to modify the
PUTPAGES stuff except in the layered-type (NULL/UNION) filesystems.

1 files changed, 125 insertions, 1 deletions

diff --git a/sys/fs/specfs/spec_vnops.c b/sys/fs/specfs/spec_vnops.c
index 8705c7b9d72e..c7430b562470 100644
--- a/sys/fs/specfs/spec_vnops.c
+++ b/sys/fs/specfs/spec_vnops.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)spec_vnops.c	8.6 (Berkeley) 4/9/94
- * $Id: spec_vnops.c,v 1.14 1995/09/04 00:20:37 dyson Exp $
+ * $Id: spec_vnops.c,v 1.15 1995/10/06 09:47:58 phk Exp $
  */
 
 #include <sys/param.h>
@@ -94,6 +94,7 @@ struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
 	{ &vop_truncate_desc, spec_truncate },		/* truncate */
 	{ &vop_update_desc, spec_update },		/* update */
 	{ &vop_bwrite_desc, vn_bwrite },		/* bwrite */
+	{ &vop_getpages_desc, spec_getpages},		/* getpages */
 	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
 };
 struct vnodeopv_desc spec_vnodeop_opv_desc =
@@ -101,6 +102,10 @@ struct vnodeopv_desc spec_vnodeop_opv_desc =
 
 VNODEOP_SET(spec_vnodeop_opv_desc);
 
+#include <vm/vm.h>
+#include <vm/vm_pager.h>
+#include <vm/vnode_pager.h>
+
 /*
  * Trivial lookup routine that always fails.
  */
@@ -706,3 +711,122 @@ spec_badop()
 	panic("spec_badop called");
 	/* NOTREACHED */
 }
+
+static void spec_getpages_iodone(struct buf *bp) {
+	bp->b_flags |= B_DONE;
+	wakeup(bp);
+}
+
+/*
+ * get page routine
+ */
+int
+spec_getpages(ap)
+	struct vop_getpages_args *ap;
+{
+	vm_offset_t kva;
+	int i, size;
+	daddr_t blkno;
+	struct buf *bp;
+	int s;
+	int error = 0;
+	int pcount;
+
+	pcount = round_page(ap->a_count) / PAGE_SIZE;
+	/*
+	 * calculate the size of the transfer
+	 */
+	blkno = (ap->a_m[0]->offset + ap->a_offset) / DEV_BSIZE;
+
+	/*
+	 * round up physical size for real devices
+	 */
+	size = (ap->a_count + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
+
+	bp = getpbuf();
+	kva = (vm_offset_t) bp->b_data;
+
+	/*
+	 * and map the pages to be read into the kva
+	 */
+	pmap_qenter(kva, ap->a_m, pcount);
+
+	/* build a minimal buffer header */
+	bp->b_flags = B_BUSY | B_READ | B_CALL;
+	bp->b_iodone = spec_getpages_iodone;
+	/* B_PHYS is not set, but it is nice to fill this in */
+	bp->b_proc = curproc;
+	bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred;
+	if (bp->b_rcred != NOCRED)
+		crhold(bp->b_rcred);
+	if (bp->b_wcred != NOCRED)
+		crhold(bp->b_wcred);
+	bp->b_blkno = blkno;
+	bp->b_lblkno = blkno;
+	pbgetvp(ap->a_vp, bp);
+	bp->b_bcount = size;
+	bp->b_bufsize = size;
+
+	cnt.v_vnodein++;
+	cnt.v_vnodepgsin += pcount;
+
+	/* do the input */
+	VOP_STRATEGY(bp);
+	if (bp->b_flags & B_ASYNC) {
+		return VM_PAGER_PEND;
+	}
+
+	s = splbio();
+	/* we definitely need to be at splbio here */
+
+	while ((bp->b_flags & B_DONE) == 0) {
+		tsleep(bp, PVM, "vnread", 0);
+	}
+	splx(s);
+	if ((bp->b_flags & B_ERROR) != 0)
+		error = EIO;
+
+	if (!error) {
+		if (ap->a_count != pcount * PAGE_SIZE) {
+			bzero((caddr_t) kva + ap->a_count,
+				PAGE_SIZE * pcount - ap->a_count);
+		}
+	}
+	pmap_qremove(kva, pcount);
+
+	/*
+	 * free the buffer header back to the swap buffer pool
+	 */
+	relpbuf(bp);
+
+	for (i = 0; i < pcount; i++) {
+		pmap_clear_modify(VM_PAGE_TO_PHYS(ap->a_m[i]));
+		ap->a_m[i]->dirty = 0;
+		ap->a_m[i]->valid = VM_PAGE_BITS_ALL;
+		if (i != ap->a_reqpage) {
+
+			/*
+			 * whether or not to leave the page activated is up in
+			 * the air, but we should put the page on a page queue
+			 * somewhere. (it already is in the object). Result:
+			 * It appears that emperical results show that
+			 * deactivating pages is best.
+			 */
+
+			/*
+			 * just in case someone was asking for this page we
+			 * now tell them that it is ok to use
+			 */
+			if (!error) {
+				vm_page_deactivate(ap->a_m[i]);
+				PAGE_WAKEUP(ap->a_m[i]);
+			} else {
+				vnode_pager_freepage(ap->a_m[i]);
+			}
+		}
+	}
+	if (error) {
+		printf("spec_getpages: I/O read error\n");
+	}
+	return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
+}