Author: avg
Date: Sat Oct 16 20:43:05 2010
New Revision: 213937
URL: http://svn.freebsd.org/changeset/base/213937
Log:
zfs: add vop_getpages method implementation
This should make vnode_pager_getpages path a bit shorter and clearer.
Also this should eliminate problems with partially valid pages.
Having this method opens room for future optimizations.
To do: try to satisfy other pages besides the required one taking into
account tradeofs between number of page faults, read throughput and read
latency. Also, eventually vop_putpages should be added too.
Reviewed by: kib, mm, pjd
MFC after: 3 weeks
Modified:
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Sat Oct
16 20:13:15 2010 (r213936)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Sat Oct
16 20:43:05 2010 (r213937)
@@ -4199,6 +4199,96 @@ ioflags(int ioflags)
}
static int
+zfs_getpages(struct vnode *vp, vm_page_t *m, int count, int reqpage)
+{
+ znode_t *zp = VTOZ(vp);
+ zfsvfs_t *zfsvfs = zp->z_zfsvfs;
+ objset_t *os = zp->z_zfsvfs->z_os;
+ vm_page_t mreq;
+ vm_object_t object;
+ caddr_t va;
+ struct sf_buf *sf;
+ int i, error;
+ int pcount, size;
+
+ ZFS_ENTER(zfsvfs);
+ ZFS_VERIFY_ZP(zp);
+
+ pcount = round_page(count) / PAGE_SIZE;
+ mreq = m[reqpage];
+ object = mreq->object;
+ error = 0;
+
+ KASSERT(vp->v_object == object, ("mismatching object"));
+
+ VM_OBJECT_LOCK(object);
+
+ for (i = 0; i < pcount; i++) {
+ if (i != reqpage) {
+ vm_page_lock(m[i]);
+ vm_page_free(m[i]);
+ vm_page_unlock(m[i]);
+ }
+ }
+
+ if (mreq->valid) {
+ if (mreq->valid != VM_PAGE_BITS_ALL)
+ vm_page_zero_invalid(mreq, TRUE);
+ VM_OBJECT_UNLOCK(object);
+ ZFS_EXIT(zfsvfs);
+ return (VM_PAGER_OK);
+ }
+
+ PCPU_INC(cnt.v_vnodein);
+ PCPU_INC(cnt.v_vnodepgsin);
+
+ if (IDX_TO_OFF(mreq->pindex) >= object->un_pager.vnp.vnp_size) {
+ VM_OBJECT_UNLOCK(object);
+ ZFS_EXIT(zfsvfs);
+ return (VM_PAGER_BAD);
+ }
+
+ size = PAGE_SIZE;
+ if (IDX_TO_OFF(mreq->pindex) + size > object->un_pager.vnp.vnp_size)
+ size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(mreq->pindex);
+
+ VM_OBJECT_UNLOCK(object);
+
+ va = zfs_map_page(mreq, &sf);
+ error = dmu_read(os, zp->z_id, IDX_TO_OFF(mreq->pindex),
+ size, va, DMU_READ_PREFETCH);
+ if (size != PAGE_SIZE)
+ bzero(va + size, PAGE_SIZE - size);
+ zfs_unmap_page(sf);
+
+ VM_OBJECT_LOCK(object);
+
+ if (!error)
+ mreq->valid = VM_PAGE_BITS_ALL;
+ KASSERT(mreq->dirty == 0, ("zfs_getpages: page %p is dirty", mreq));
+
+ VM_OBJECT_UNLOCK(object);
+
+ ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
+ ZFS_EXIT(zfsvfs);
+ return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
+}
+
+static int
+zfs_freebsd_getpages(ap)
+ struct vop_getpages_args /* {
+ struct vnode *a_vp;
+ vm_page_t *a_m;
+ int a_count;
+ int a_reqpage;
+ vm_ooffset_t a_offset;
+ } */ *ap;
+{
+
+ return (zfs_getpages(ap->a_vp, ap->a_m, ap->a_count, ap->a_reqpage));
+}
+
+static int
zfs_freebsd_open(ap)
struct vop_open_args /* {
struct vnode *a_vp;
@@ -5314,6 +5404,7 @@ struct vop_vector zfs_vnodeops = {
.vop_getacl = zfs_freebsd_getacl,
.vop_setacl = zfs_freebsd_setacl,
.vop_aclcheck = zfs_freebsd_aclcheck,
+ .vop_getpages = zfs_freebsd_getpages,
};
struct vop_vector zfs_fifoops = {
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