Viewing: vvp_page.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
* Copyright (c) 2011, 2017, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
*
* Implementation of cl_page for VVP layer.
*
* Author: Nikita Danilov <nikita.danilov@sun.com>
* Author: Jinshan Xiong <jinshan.xiong@whamcloud.com>
*/
#define DEBUG_SUBSYSTEM S_LLITE
#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/page-flags.h>
#include <linux/pagemap.h>
#include "llite_internal.h"
#include "vvp_internal.h"
/* Page operations */
static void vvp_page_discard(const struct lu_env *env,
const struct cl_page_slice *slice,
struct cl_io *unused)
{
struct cl_page *cp = slice->cpl_page;
struct page *vmpage = cp->cp_vmpage;
if (cp->cp_defer_uptodate && !cp->cp_ra_used && vmpage->mapping != NULL)
ll_ra_stats_inc(vmpage->mapping->host, RA_STAT_DISCARDED);
}
static void vvp_page_delete(const struct lu_env *env,
const struct cl_page_slice *slice)
{
struct cl_page *cp = slice->cpl_page;
if (cp->cp_type == CPT_CACHEABLE) {
struct page *vmpage = cp->cp_vmpage;
struct inode *inode = vmpage->mapping->host;
LASSERT((struct cl_page *)vmpage->private == cp);
CDEBUG(D_CACHE, "delete page %pK index %ld\n",
vmpage, folio_index_page(vmpage));
/* Drop the reference count held in vvp_page_init */
refcount_dec(&cp->cp_ref);
ClearPagePrivate(vmpage);
vmpage->private = 0;
/* clearpageuptodate prevents the page being read by the
* kernel after it has been deleted from Lustre, which avoids
* potential stale data reads. The seqlock allows us to see
* that a page was potentially deleted and catch the resulting
* SIGBUS - see ll_filemap_fault() (LU-16160)
*/
if (PageUptodate(vmpage)) {
write_seqlock(&ll_i2info(inode)->lli_page_inv_lock);
ClearPageUptodate(vmpage);
write_sequnlock(&ll_i2info(inode)->lli_page_inv_lock);
}
/* The reference from vmpage to cl_page is removed,
* but the reference back is still here. It is removed
* later in cl_page_free().
*/
}
}
/**
* vvp_vmpage_error() - Handles page transfer errors at VM level.
*
* @inode: inode linked with vmpage(struct page)
* @vmpage: struct page that has error
* @ioret: type of error
*
* This takes inode as a separate argument, because inode on which error is to
* be set can be different from \a vmpage inode in case of direct-io.
*/
static void vvp_vmpage_error(struct inode *inode, struct page *vmpage,
int ioret)
{
struct vvp_object *obj = cl_inode2vvp(inode);
if (ioret == 0) {
ClearPageError(vmpage);
obj->vob_discard_page_warned = 0;
} else {
SetPageError(vmpage);
if (CFS_FAIL_CHECK(OBD_FAIL_LLITE_PANIC_ON_ESTALE))
LASSERTF(ioret == -ENOSPC,
"%s:"DFID" got a stale page %p: rc = %d.\n",
obj->vob_cl.co_lu.lo_dev->ld_obd->obd_name,
PFID(lu_object_fid(&obj->vob_cl.co_lu)),
vmpage, ioret);
mapping_set_error(inode->i_mapping, ioret);
if ((ioret == -ESHUTDOWN || ioret == -EINTR ||
ioret == -EIO) && obj->vob_discard_page_warned == 0) {
obj->vob_discard_page_warned = 1;
ll_dirty_page_discard_warn(inode, ioret);
}
}
}
static void vvp_page_complete_read(const struct lu_env *env,
const struct cl_page_slice *slice,
int ioret)
{
struct cl_page *cp = slice->cpl_page;
struct page *vmpage = cp->cp_vmpage;
struct inode *inode = vvp_object_inode(cp->cp_obj);
ENTRY;
LASSERT(PageLocked(vmpage));
CL_PAGE_HEADER(D_PAGE, env, cp, "completing READ with %d\n", ioret);
if (cp->cp_defer_uptodate)
ll_ra_count_put(ll_i2sbi(inode), 1);
if (ioret == 0) {
/**
* cp_defer_uptodate is used for readahead page, and the
* vmpage Uptodate bit is deferred to set in ll_readpage/
* ll_io_read_page.
*/
if (!cp->cp_defer_uptodate)
SetPageUptodate(vmpage);
} else if (cp->cp_defer_uptodate) {
cp->cp_defer_uptodate = 0;
if (ioret == -EAGAIN) {
/* mirror read failed, it needs to destroy the page
* because subpage would be from wrong osc when trying
* to read from a new mirror
*/
generic_error_remove_folio(vmpage->mapping,
page_folio(vmpage));
}
}
if (cp->cp_sync_io == NULL)
unlock_page(vmpage);
EXIT;
}
static void vvp_page_complete_write(const struct lu_env *env,
const struct cl_page_slice *slice,
int ioret)
{
struct cl_page *cp = slice->cpl_page;
struct page *vmpage = cp->cp_vmpage;
ENTRY;
CL_PAGE_HEADER(D_PAGE, env, cp, "completing WRITE with %d\n", ioret);
if (cp->cp_sync_io != NULL) {
LASSERT(PageLocked(vmpage));
LASSERT(!PageWriteback(vmpage));
} else {
LASSERT(PageWriteback(vmpage));
/*
* Only mark the page error only when it's an async write
* because applications won't wait for IO to finish.
*/
vvp_vmpage_error(vvp_object_inode(cp->cp_obj), vmpage, ioret);
end_page_writeback(vmpage);
}
EXIT;
}
static const struct cl_page_operations vvp_page_ops = {
.cpo_delete = vvp_page_delete,
.cpo_discard = vvp_page_discard,
.io = {
[CRT_READ] = {
.cpo_complete = vvp_page_complete_read,
},
[CRT_WRITE] = {
.cpo_complete = vvp_page_complete_write,
},
},
};
static const struct cl_page_operations vvp_transient_page_ops = {
};
int vvp_page_init(const struct lu_env *env, struct cl_object *obj,
struct cl_page *page, pgoff_t index)
{
struct cl_page_slice *cpl = cl_object_page_slice(obj, page);
struct page *vmpage = page->cp_vmpage;
CLOBINVRNT(env, obj, vvp_object_invariant(obj));
if (page->cp_type == CPT_TRANSIENT) {
/* DIO pages are referenced by userspace, we don't need to take
* a reference on them. (contrast with get_page() call above)
*/
cl_page_slice_add(page, cpl, obj,
&vvp_transient_page_ops);
} else {
get_page(vmpage);
/* in cache, decref in cl_page_delete() */
refcount_inc(&page->cp_ref);
SetPagePrivate(vmpage);
vmpage->private = (unsigned long)page;
cl_page_slice_add(page, cpl, obj, &vvp_page_ops);
}
return 0;
}
