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/*
* Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Hyra nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/sio.h>
#include <sys/vfs.h>
#include <sys/cdefs.h>
#include <vm/obj.h>
#include <vm/vm.h>
#include <vm/pager.h>
static int vn_pager_get(struct vm_object *obj, off_t off, size_t len,
struct vm_page *pg);
static int vn_pager_store(struct vm_object *obj, off_t off, size_t len,
struct vm_page *pg);
/* Pager operations */
struct vm_pagerops g_vnode_pagerops = {
.get = vn_pager_get,
.store = vn_pager_store
};
static inline void
vn_prep_sio(struct sio_txn *sio, char *pg, off_t off, size_t len)
{
sio->len = __ALIGN_DOWN(len, vm_get_page_size());
sio->buf = pg;
sio->offset = off;
sio->len = len;
}
static int
vn_pager_io(struct vm_object *obj, off_t off, size_t len,
struct vm_page *pg, bool out)
{
struct sio_txn sio;
struct vnode *vp;
ssize_t paged_bytes;
char *dest;
int res = 0;
if (obj == NULL || pg == NULL) {
return -EIO;
}
spinlock_acquire(&obj->lock);
vm_object_ref(obj);
dest = PHYS_TO_VIRT(pg->physaddr);
/* Attempt to fetch the vnode */
if ((vp = obj->vnode) == NULL) {
res = -EIO;
goto done;
}
/* Prepare the SIO transaction */
vn_prep_sio(&sio, dest, off, len);
if (sio.len == 0) {
res = -EIO;
goto done;
}
/* Perform I/O on the backing store */
paged_bytes = out ? vfs_write(vp, &sio) : vfs_read(vp, &sio);
if (paged_bytes < 0) {
/* Failure */
res = paged_bytes;
goto done;
}
done:
vm_object_unref(obj);
spinlock_release(&obj->lock);
return res;
}
static int
vn_pager_store(struct vm_object *obj, off_t off, size_t len, struct vm_page *pg)
{
return vn_pager_io(obj, off, len, pg, true);
}
static int
vn_pager_get(struct vm_object *obj, off_t off, size_t len, struct vm_page *pg)
{
return vn_pager_io(obj, off, len, pg, false);
}
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