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13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
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18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, 2017, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
31 * Implementation of cl_page for VVP layer.
33 * Author: Nikita Danilov <nikita.danilov@sun.com>
34 * Author: Jinshan Xiong <jinshan.xiong@whamcloud.com>
37 #define DEBUG_SUBSYSTEM S_LLITE
39 #include <linux/atomic.h>
40 #include <linux/bitops.h>
42 #include <linux/mutex.h>
43 #include <linux/page-flags.h>
44 #include <linux/pagemap.h>
46 #include <libcfs/libcfs.h>
47 #include "llite_internal.h"
48 #include "vvp_internal.h"
50 /*****************************************************************************
55 static void vvp_page_discard(const struct lu_env *env,
56 const struct cl_page_slice *slice,
59 struct cl_page *cp = slice->cpl_page;
60 struct page *vmpage = cp->cp_vmpage;
62 if (cp->cp_defer_uptodate && !cp->cp_ra_used && vmpage->mapping != NULL)
63 ll_ra_stats_inc(vmpage->mapping->host, RA_STAT_DISCARDED);
66 static void vvp_page_delete(const struct lu_env *env,
67 const struct cl_page_slice *slice)
69 struct cl_page *cp = slice->cpl_page;
71 if (cp->cp_type == CPT_CACHEABLE) {
72 struct page *vmpage = cp->cp_vmpage;
73 struct inode *inode = vmpage->mapping->host;
75 LASSERT(PageLocked(vmpage));
76 LASSERT((struct cl_page *)vmpage->private == cp);
78 /* Drop the reference count held in vvp_page_init */
79 refcount_dec(&cp->cp_ref);
81 ClearPagePrivate(vmpage);
84 /* clearpageuptodate prevents the page being read by the
85 * kernel after it has been deleted from Lustre, which avoids
86 * potential stale data reads. The seqlock allows us to see
87 * that a page was potentially deleted and catch the resulting
88 * SIGBUS - see ll_filemap_fault() (LU-16160)
90 if (PageUptodate(vmpage)) {
91 write_seqlock(&ll_i2info(inode)->lli_page_inv_lock);
92 ClearPageUptodate(vmpage);
93 write_sequnlock(&ll_i2info(inode)->lli_page_inv_lock);
95 /* The reference from vmpage to cl_page is removed,
96 * but the reference back is still here. It is removed
97 * later in cl_page_free().
103 * Handles page transfer errors at VM level.
105 * This takes inode as a separate argument, because inode on which error is to
106 * be set can be different from \a vmpage inode in case of direct-io.
108 static void vvp_vmpage_error(struct inode *inode, struct page *vmpage,
111 struct vvp_object *obj = cl_inode2vvp(inode);
114 ClearPageError(vmpage);
115 obj->vob_discard_page_warned = 0;
117 SetPageError(vmpage);
118 if (ioret != -ENOSPC &&
119 CFS_FAIL_CHECK(OBD_FAIL_LLITE_PANIC_ON_ESTALE))
122 mapping_set_error(inode->i_mapping, ioret);
124 if ((ioret == -ESHUTDOWN || ioret == -EINTR ||
125 ioret == -EIO) && obj->vob_discard_page_warned == 0) {
126 obj->vob_discard_page_warned = 1;
127 ll_dirty_page_discard_warn(inode, ioret);
132 static void vvp_page_completion_read(const struct lu_env *env,
133 const struct cl_page_slice *slice,
136 struct cl_page *cp = slice->cpl_page;
137 struct page *vmpage = cp->cp_vmpage;
138 struct inode *inode = vvp_object_inode(cp->cp_obj);
141 LASSERT(PageLocked(vmpage));
142 CL_PAGE_HEADER(D_PAGE, env, cp, "completing READ with %d\n", ioret);
144 if (cp->cp_defer_uptodate)
145 ll_ra_count_put(ll_i2sbi(inode), 1);
149 * cp_defer_uptodate is used for readahead page, and the
150 * vmpage Uptodate bit is deferred to set in ll_readpage/
153 if (!cp->cp_defer_uptodate)
154 SetPageUptodate(vmpage);
155 } else if (cp->cp_defer_uptodate) {
156 cp->cp_defer_uptodate = 0;
157 if (ioret == -EAGAIN) {
158 /* mirror read failed, it needs to destroy the page
159 * because subpage would be from wrong osc when trying
160 * to read from a new mirror
162 generic_error_remove_folio(vmpage->mapping,
167 if (cp->cp_sync_io == NULL)
173 static void vvp_page_completion_write(const struct lu_env *env,
174 const struct cl_page_slice *slice,
177 struct cl_page *cp = slice->cpl_page;
178 struct page *vmpage = cp->cp_vmpage;
181 CL_PAGE_HEADER(D_PAGE, env, cp, "completing WRITE with %d\n", ioret);
183 if (cp->cp_sync_io != NULL) {
184 LASSERT(PageLocked(vmpage));
185 LASSERT(!PageWriteback(vmpage));
187 LASSERT(PageWriteback(vmpage));
189 * Only mark the page error only when it's an async write
190 * because applications won't wait for IO to finish.
192 vvp_vmpage_error(vvp_object_inode(cp->cp_obj), vmpage, ioret);
194 end_page_writeback(vmpage);
199 static const struct cl_page_operations vvp_page_ops = {
200 .cpo_delete = vvp_page_delete,
201 .cpo_discard = vvp_page_discard,
204 .cpo_completion = vvp_page_completion_read,
207 .cpo_completion = vvp_page_completion_write,
212 static const struct cl_page_operations vvp_transient_page_ops = {
215 int vvp_page_init(const struct lu_env *env, struct cl_object *obj,
216 struct cl_page *page, pgoff_t index)
218 struct cl_page_slice *cpl = cl_object_page_slice(obj, page);
219 struct page *vmpage = page->cp_vmpage;
221 CLOBINVRNT(env, obj, vvp_object_invariant(obj));
223 if (page->cp_type == CPT_TRANSIENT) {
224 /* DIO pages are referenced by userspace, we don't need to take
225 * a reference on them. (contrast with get_page() call above)
227 cl_page_slice_add(page, cpl, obj,
228 &vvp_transient_page_ops);
231 /* in cache, decref in cl_page_delete() */
232 refcount_inc(&page->cp_ref);
233 SetPagePrivate(vmpage);
234 vmpage->private = (unsigned long)page;
235 cl_page_slice_add(page, cpl, obj, &vvp_page_ops);