4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, 2016, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
32 * lustre/lustre/llite/rw26.c
34 * Lustre Lite I/O page cache routines for the 2.5/2.6 kernel version
37 #include <linux/kernel.h>
39 #include <linux/string.h>
40 #include <linux/stat.h>
41 #include <linux/errno.h>
42 #include <linux/unistd.h>
43 #include <asm/uaccess.h>
46 #include <linux/migrate.h>
47 #elif defined(HAVE_MIGRATE_MODE_H)
48 #include <linux/migrate_mode.h>
51 #include <linux/buffer_head.h>
52 #include <linux/mpage.h>
53 #include <linux/writeback.h>
54 #include <linux/stat.h>
55 #include <asm/uaccess.h>
57 #include <linux/pagemap.h>
59 #define DEBUG_SUBSYSTEM S_LLITE
61 #include "llite_internal.h"
62 #include <lustre_compat.h>
65 * Implements Linux VM address_space::invalidatepage() method. This method is
66 * called when the page is truncate from a file, either as a result of
67 * explicit truncate, or when inode is removed from memory (as a result of
68 * final iput(), umount, or memory pressure induced icache shrinking).
70 * [0, offset] bytes of the page remain valid (this is for a case of not-page
71 * aligned truncate). Lustre leaves partially truncated page in the cache,
72 * relying on struct inode::i_size to limit further accesses.
74 static void ll_invalidatepage(struct page *vmpage,
75 #ifdef HAVE_INVALIDATE_RANGE
76 unsigned int offset, unsigned int length
85 struct cl_object *obj;
87 LASSERT(PageLocked(vmpage));
88 LASSERT(!PageWriteback(vmpage));
91 * It is safe to not check anything in invalidatepage/releasepage
92 * below because they are run with page locked and all our io is
93 * happening with locked page too
95 #ifdef HAVE_INVALIDATE_RANGE
96 if (offset == 0 && length == PAGE_SIZE) {
100 /* See the comment in ll_releasepage() */
101 env = cl_env_percpu_get();
102 LASSERT(!IS_ERR(env));
104 inode = vmpage->mapping->host;
105 obj = ll_i2info(inode)->lli_clob;
107 page = cl_vmpage_page(vmpage, obj);
109 cl_page_delete(env, page);
110 cl_page_put(env, page);
113 LASSERT(vmpage->private == 0);
115 cl_env_percpu_put(env);
119 #ifdef HAVE_RELEASEPAGE_WITH_INT
120 #define RELEASEPAGE_ARG_TYPE int
122 #define RELEASEPAGE_ARG_TYPE gfp_t
124 static int ll_releasepage(struct page *vmpage, RELEASEPAGE_ARG_TYPE gfp_mask)
127 struct cl_object *obj;
128 struct cl_page *page;
129 struct address_space *mapping;
132 LASSERT(PageLocked(vmpage));
133 if (PageWriteback(vmpage) || PageDirty(vmpage))
136 mapping = vmpage->mapping;
140 obj = ll_i2info(mapping->host)->lli_clob;
144 /* 1 for caller, 1 for cl_page and 1 for page cache */
145 if (page_count(vmpage) > 3)
148 page = cl_vmpage_page(vmpage, obj);
152 env = cl_env_percpu_get();
153 LASSERT(!IS_ERR(env));
155 if (!cl_page_in_use(page)) {
157 cl_page_delete(env, page);
160 /* To use percpu env array, the call path can not be rescheduled;
161 * otherwise percpu array will be messed if ll_releaspage() called
162 * again on the same CPU.
164 * If this page holds the last refc of cl_object, the following
165 * call path may cause reschedule:
166 * cl_page_put -> cl_page_free -> cl_object_put ->
167 * lu_object_put -> lu_object_free -> lov_delete_raid0.
169 * However, the kernel can't get rid of this inode until all pages have
170 * been cleaned up. Now that we hold page lock here, it's pretty safe
171 * that we won't get into object delete path.
173 LASSERT(cl_object_refc(obj) > 1);
174 cl_page_put(env, page);
176 cl_env_percpu_put(env);
180 #define MAX_DIRECTIO_SIZE 2*1024*1024*1024UL
182 ssize_t ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io,
183 int rw, struct inode *inode,
184 struct ll_dio_pages *pv)
187 struct cl_2queue *queue;
188 struct cl_object *obj = io->ci_obj;
191 loff_t file_offset = pv->ldp_start_offset;
192 size_t size = pv->ldp_size;
193 int page_count = pv->ldp_nr;
194 struct page **pages = pv->ldp_pages;
195 size_t page_size = cl_page_size(obj);
200 queue = &io->ci_queue;
201 cl_2queue_init(queue);
202 for (i = 0; i < page_count; i++) {
204 file_offset = pv->ldp_offsets[i];
206 LASSERT(!(file_offset & (page_size - 1)));
207 clp = cl_page_find(env, obj, cl_index(obj, file_offset),
208 pv->ldp_pages[i], CPT_TRANSIENT);
214 rc = cl_page_own(env, io, clp);
216 LASSERT(clp->cp_state == CPS_FREEING);
217 cl_page_put(env, clp);
223 /* check the page type: if the page is a host page, then do
225 if (clp->cp_type == CPT_CACHEABLE) {
226 struct page *vmpage = cl_page_vmpage(clp);
227 struct page *src_page;
228 struct page *dst_page;
232 src_page = (rw == WRITE) ? pages[i] : vmpage;
233 dst_page = (rw == WRITE) ? vmpage : pages[i];
235 src = ll_kmap_atomic(src_page, KM_USER0);
236 dst = ll_kmap_atomic(dst_page, KM_USER1);
237 memcpy(dst, src, min(page_size, size));
238 ll_kunmap_atomic(dst, KM_USER1);
239 ll_kunmap_atomic(src, KM_USER0);
241 /* make sure page will be added to the transfer by
242 * cl_io_submit()->...->vvp_page_prep_write(). */
244 set_page_dirty(vmpage);
247 /* do not issue the page for read, since it
248 * may reread a ra page which has NOT uptodate
250 cl_page_disown(env, io, clp);
256 cl_2queue_add(queue, clp);
259 * Set page clip to tell transfer formation engine
260 * that page has to be sent even if it is beyond KMS.
262 cl_page_clip(env, clp, 0, min(size, page_size));
267 /* drop the reference count for cl_page_find */
268 cl_page_put(env, clp);
270 file_offset += page_size;
273 if (rc == 0 && io_pages) {
274 rc = cl_io_submit_sync(env, io,
275 rw == READ ? CRT_READ : CRT_WRITE,
281 cl_2queue_discard(env, io, queue);
282 cl_2queue_disown(env, io, queue);
283 cl_2queue_fini(env, queue);
286 EXPORT_SYMBOL(ll_direct_rw_pages);
289 ll_direct_IO_seg(const struct lu_env *env, struct cl_io *io, int rw,
290 struct inode *inode, size_t size, loff_t file_offset,
291 struct page **pages, int page_count)
293 struct ll_dio_pages pvec = { .ldp_pages = pages,
294 .ldp_nr = page_count,
297 .ldp_start_offset = file_offset
300 return ll_direct_rw_pages(env, io, rw, inode, &pvec);
303 /* ll_free_user_pages - tear down page struct array
304 * @pages: array of page struct pointers underlying target buffer */
305 static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
309 for (i = 0; i < npages; i++) {
310 if (pages[i] == NULL)
313 set_page_dirty_lock(pages[i]);
317 #if defined(HAVE_DIRECTIO_ITER) || defined(HAVE_IOV_ITER_RW)
320 OBD_FREE_LARGE(pages, npages * sizeof(*pages));
324 #ifdef KMALLOC_MAX_SIZE
325 #define MAX_MALLOC KMALLOC_MAX_SIZE
327 #define MAX_MALLOC (128 * 1024)
330 /* This is the maximum size of a single O_DIRECT request, based on the
331 * kmalloc limit. We need to fit all of the brw_page structs, each one
332 * representing PAGE_SIZE worth of user data, into a single buffer, and
333 * then truncate this to be a full-sized RPC. For 4kB PAGE_SIZE this is
334 * up to 22MB for 128kB kmalloc and up to 682MB for 4MB kmalloc. */
335 #define MAX_DIO_SIZE ((MAX_MALLOC / sizeof(struct brw_page) * PAGE_SIZE) & \
336 ~(DT_MAX_BRW_SIZE - 1))
338 #ifndef HAVE_IOV_ITER_RW
339 # define iov_iter_rw(iter) rw
342 #if defined(HAVE_DIRECTIO_ITER) || defined(HAVE_IOV_ITER_RW)
345 # ifndef HAVE_IOV_ITER_RW
348 struct kiocb *iocb, struct iov_iter *iter
349 # ifndef HAVE_DIRECTIO_2ARGS
354 #ifdef HAVE_DIRECTIO_2ARGS
355 loff_t file_offset = iocb->ki_pos;
357 struct ll_cl_context *lcc;
358 const struct lu_env *env;
360 struct file *file = iocb->ki_filp;
361 struct inode *inode = file->f_mapping->host;
362 ssize_t count = iov_iter_count(iter);
363 ssize_t tot_bytes = 0, result = 0;
364 size_t size = MAX_DIO_SIZE;
366 /* Check EOF by ourselves */
367 if (iov_iter_rw(iter) == READ && file_offset >= i_size_read(inode))
369 /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
370 if ((file_offset & ~PAGE_MASK) || (count & ~PAGE_MASK))
373 CDEBUG(D_VFSTRACE, "VFS Op:inode="DFID"(%p), size=%zd (max %lu), "
374 "offset=%lld=%llx, pages %zd (max %lu)\n",
375 PFID(ll_inode2fid(inode)), inode, count, MAX_DIO_SIZE,
376 file_offset, file_offset, count >> PAGE_SHIFT,
377 MAX_DIO_SIZE >> PAGE_SHIFT);
379 /* Check that all user buffers are aligned as well */
380 if (iov_iter_alignment(iter) & ~PAGE_MASK)
383 lcc = ll_cl_find(file);
388 LASSERT(!IS_ERR(env));
392 /* 0. Need locking between buffered and direct access. and race with
393 * size changing by concurrent truncates and writes.
394 * 1. Need inode mutex to operate transient pages.
396 if (iov_iter_rw(iter) == READ)
399 while (iov_iter_count(iter)) {
403 count = min_t(size_t, iov_iter_count(iter), size);
404 if (iov_iter_rw(iter) == READ) {
405 if (file_offset >= i_size_read(inode))
408 if (file_offset + count > i_size_read(inode))
409 count = i_size_read(inode) - file_offset;
412 result = iov_iter_get_pages_alloc(iter, &pages, count, &offs);
413 if (likely(result > 0)) {
414 int n = DIV_ROUND_UP(result + offs, PAGE_SIZE);
416 result = ll_direct_IO_seg(env, io, iov_iter_rw(iter),
417 inode, result, file_offset,
419 ll_free_user_pages(pages, n,
420 iov_iter_rw(iter) == READ);
423 if (unlikely(result <= 0)) {
424 /* If we can't allocate a large enough buffer
425 * for the request, shrink it to a smaller
426 * PAGE_SIZE multiple and try again.
427 * We should always be able to kmalloc for a
428 * page worth of page pointers = 4MB on i386. */
429 if (result == -ENOMEM &&
430 size > (PAGE_SIZE / sizeof(*pages)) *
432 size = ((((size / 2) - 1) |
433 ~PAGE_MASK) + 1) & PAGE_MASK;
434 CDEBUG(D_VFSTRACE, "DIO size now %zu\n",
442 iov_iter_advance(iter, result);
444 file_offset += result;
447 if (iov_iter_rw(iter) == READ)
451 struct vvp_io *vio = vvp_env_io(env);
453 /* no commit async for direct IO */
454 vio->u.write.vui_written += tot_bytes;
457 return tot_bytes ? : result;
459 #else /* !HAVE_DIRECTIO_ITER && !HAVE_IOV_ITER_RW */
461 static inline int ll_get_user_pages(int rw, unsigned long user_addr,
462 size_t size, struct page ***pages,
465 int result = -ENOMEM;
467 /* set an arbitrary limit to prevent arithmetic overflow */
468 if (size > MAX_DIRECTIO_SIZE) {
473 *max_pages = (user_addr + size + PAGE_SIZE - 1) >>
475 *max_pages -= user_addr >> PAGE_SHIFT;
477 OBD_ALLOC_LARGE(*pages, *max_pages * sizeof(**pages));
479 down_read(¤t->mm->mmap_sem);
480 result = get_user_pages(current, current->mm, user_addr,
481 *max_pages, (rw == READ), 0, *pages,
483 up_read(¤t->mm->mmap_sem);
484 if (unlikely(result <= 0))
485 OBD_FREE_LARGE(*pages, *max_pages * sizeof(**pages));
492 ll_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
493 loff_t file_offset, unsigned long nr_segs)
495 struct ll_cl_context *lcc;
496 const struct lu_env *env;
498 struct file *file = iocb->ki_filp;
499 struct inode *inode = file->f_mapping->host;
500 ssize_t count = iov_length(iov, nr_segs);
501 ssize_t tot_bytes = 0, result = 0;
502 unsigned long seg = 0;
503 size_t size = MAX_DIO_SIZE;
506 /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
507 if ((file_offset & ~PAGE_MASK) || (count & ~PAGE_MASK))
510 CDEBUG(D_VFSTRACE, "VFS Op:inode="DFID"(%p), size=%zd (max %lu), "
511 "offset=%lld=%llx, pages %zd (max %lu)\n",
512 PFID(ll_inode2fid(inode)), inode, count, MAX_DIO_SIZE,
513 file_offset, file_offset, count >> PAGE_SHIFT,
514 MAX_DIO_SIZE >> PAGE_SHIFT);
516 /* Check that all user buffers are aligned as well */
517 for (seg = 0; seg < nr_segs; seg++) {
518 if (((unsigned long)iov[seg].iov_base & ~PAGE_MASK) ||
519 (iov[seg].iov_len & ~PAGE_MASK))
523 lcc = ll_cl_find(file);
528 LASSERT(!IS_ERR(env));
532 for (seg = 0; seg < nr_segs; seg++) {
533 size_t iov_left = iov[seg].iov_len;
534 unsigned long user_addr = (unsigned long)iov[seg].iov_base;
537 if (file_offset >= i_size_read(inode))
539 if (file_offset + iov_left > i_size_read(inode))
540 iov_left = i_size_read(inode) - file_offset;
543 while (iov_left > 0) {
545 int page_count, max_pages = 0;
548 bytes = min(size, iov_left);
549 page_count = ll_get_user_pages(rw, user_addr, bytes,
551 if (likely(page_count > 0)) {
552 if (unlikely(page_count < max_pages))
553 bytes = page_count << PAGE_SHIFT;
554 result = ll_direct_IO_seg(env, io, rw, inode,
557 ll_free_user_pages(pages, max_pages, rw==READ);
558 } else if (page_count == 0) {
559 GOTO(out, result = -EFAULT);
563 if (unlikely(result <= 0)) {
564 /* If we can't allocate a large enough buffer
565 * for the request, shrink it to a smaller
566 * PAGE_SIZE multiple and try again.
567 * We should always be able to kmalloc for a
568 * page worth of page pointers = 4MB on i386. */
569 if (result == -ENOMEM &&
570 size > (PAGE_SIZE / sizeof(*pages)) *
572 size = ((((size / 2) - 1) |
575 CDEBUG(D_VFSTRACE, "DIO size now %zu\n",
584 file_offset += result;
591 struct vvp_io *vio = vvp_env_io(env);
593 /* no commit async for direct IO */
594 vio->u.write.vui_written += tot_bytes;
597 RETURN(tot_bytes ? tot_bytes : result);
599 #endif /* HAVE_DIRECTIO_ITER || HAVE_IOV_ITER_RW */
602 * Prepare partially written-to page for a write.
604 static int ll_prepare_partial_page(const struct lu_env *env, struct cl_io *io,
607 struct cl_attr *attr = vvp_env_thread_attr(env);
608 struct cl_object *obj = io->ci_obj;
609 struct vvp_page *vpg = cl_object_page_slice(obj, pg);
610 loff_t offset = cl_offset(obj, vvp_index(vpg));
613 cl_object_attr_lock(obj);
614 result = cl_object_attr_get(env, obj, attr);
615 cl_object_attr_unlock(obj);
618 * If are writing to a new page, no need to read old data.
619 * The extent locking will have updated the KMS, and for our
620 * purposes here we can treat it like i_size.
622 if (attr->cat_kms <= offset) {
623 char *kaddr = ll_kmap_atomic(vpg->vpg_page, KM_USER0);
625 memset(kaddr, 0, cl_page_size(obj));
626 ll_kunmap_atomic(kaddr, KM_USER0);
627 } else if (vpg->vpg_defer_uptodate)
628 vpg->vpg_ra_used = 1;
630 result = ll_page_sync_io(env, io, pg, CRT_READ);
635 static int ll_write_begin(struct file *file, struct address_space *mapping,
636 loff_t pos, unsigned len, unsigned flags,
637 struct page **pagep, void **fsdata)
639 struct ll_cl_context *lcc;
640 const struct lu_env *env = NULL;
642 struct cl_page *page = NULL;
644 struct cl_object *clob = ll_i2info(mapping->host)->lli_clob;
645 pgoff_t index = pos >> PAGE_SHIFT;
646 struct page *vmpage = NULL;
647 unsigned from = pos & (PAGE_SIZE - 1);
648 unsigned to = from + len;
652 CDEBUG(D_PAGE, "Writing %lu of %d to %d bytes\n", index, from, len);
654 lcc = ll_cl_find(file);
657 GOTO(out, result = -EIO);
663 /* To avoid deadlock, try to lock page first. */
664 vmpage = grab_cache_page_nowait(mapping, index);
666 if (unlikely(vmpage == NULL ||
667 PageDirty(vmpage) || PageWriteback(vmpage))) {
668 struct vvp_io *vio = vvp_env_io(env);
669 struct cl_page_list *plist = &vio->u.write.vui_queue;
671 /* if the page is already in dirty cache, we have to commit
672 * the pages right now; otherwise, it may cause deadlock
673 * because it holds page lock of a dirty page and request for
674 * more grants. It's okay for the dirty page to be the first
675 * one in commit page list, though. */
676 if (vmpage != NULL && plist->pl_nr > 0) {
682 /* commit pages and then wait for page lock */
683 result = vvp_io_write_commit(env, io);
687 if (vmpage == NULL) {
688 vmpage = grab_cache_page_write_begin(mapping, index,
691 GOTO(out, result = -ENOMEM);
695 page = cl_page_find(env, clob, vmpage->index, vmpage, CPT_CACHEABLE);
697 GOTO(out, result = PTR_ERR(page));
699 lcc->lcc_page = page;
700 lu_ref_add(&page->cp_reference, "cl_io", io);
702 cl_page_assume(env, io, page);
703 if (!PageUptodate(vmpage)) {
705 * We're completely overwriting an existing page,
706 * so _don't_ set it up to date until commit_write
708 if (from == 0 && to == PAGE_SIZE) {
709 CL_PAGE_HEADER(D_PAGE, env, page, "full page write\n");
710 POISON_PAGE(vmpage, 0x11);
712 /* TODO: can be optimized at OSC layer to check if it
713 * is a lockless IO. In that case, it's not necessary
714 * to read the data. */
715 result = ll_prepare_partial_page(env, io, page);
717 SetPageUptodate(vmpage);
721 cl_page_unassume(env, io, page);
725 if (vmpage != NULL) {
729 if (!IS_ERR_OR_NULL(page)) {
730 lu_ref_del(&page->cp_reference, "cl_io", io);
731 cl_page_put(env, page);
734 io->ci_result = result;
742 static int ll_write_end(struct file *file, struct address_space *mapping,
743 loff_t pos, unsigned len, unsigned copied,
744 struct page *vmpage, void *fsdata)
746 struct ll_cl_context *lcc = fsdata;
747 const struct lu_env *env;
750 struct cl_page *page;
751 unsigned from = pos & (PAGE_SIZE - 1);
758 LASSERT(lcc != NULL);
760 page = lcc->lcc_page;
762 vio = vvp_env_io(env);
764 LASSERT(cl_page_is_owned(page, io));
766 struct cl_page_list *plist = &vio->u.write.vui_queue;
768 lcc->lcc_page = NULL; /* page will be queued */
770 /* Add it into write queue */
771 cl_page_list_add(plist, page);
772 if (plist->pl_nr == 1) /* first page */
773 vio->u.write.vui_from = from;
776 vio->u.write.vui_to = from + copied;
778 /* To address the deadlock in balance_dirty_pages() where
779 * this dirty page may be written back in the same thread. */
780 if (PageDirty(vmpage))
783 /* We may have one full RPC, commit it soon */
784 if (plist->pl_nr >= PTLRPC_MAX_BRW_PAGES)
787 CL_PAGE_DEBUG(D_PAGE, env, page,
788 "queued page: %d.\n", plist->pl_nr);
790 cl_page_disown(env, io, page);
792 lcc->lcc_page = NULL;
793 lu_ref_del(&page->cp_reference, "cl_io", io);
794 cl_page_put(env, page);
796 /* page list is not contiguous now, commit it now */
800 file->f_flags & O_SYNC || IS_SYNC(file_inode(file)))
801 result = vvp_io_write_commit(env, io);
804 io->ci_result = result;
805 RETURN(result >= 0 ? copied : result);
808 #ifdef CONFIG_MIGRATION
809 static int ll_migratepage(struct address_space *mapping,
810 struct page *newpage, struct page *page
811 #ifdef HAVE_MIGRATEPAGE_4ARGS
812 , enum migrate_mode mode
816 /* Always fail page migration until we have a proper implementation */
821 const struct address_space_operations ll_aops = {
822 .readpage = ll_readpage,
823 .direct_IO = ll_direct_IO,
824 .writepage = ll_writepage,
825 .writepages = ll_writepages,
826 .set_page_dirty = __set_page_dirty_nobuffers,
827 .write_begin = ll_write_begin,
828 .write_end = ll_write_end,
829 .invalidatepage = ll_invalidatepage,
830 .releasepage = (void *)ll_releasepage,
831 #ifdef CONFIG_MIGRATION
832 .migratepage = ll_migratepage,