-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
+/*
+ * GPL HEADER START
*
- * Lustre Lite I/O page cache routines for the 2.5/2.6 kernel version
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
*
- * Copyright (c) 2001-2003 Cluster File Systems, Inc.
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.gnu.org/licenses/gpl-2.0.html
*
- * This file is part of Lustre, http://www.lustre.org.
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
*
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
+ * Copyright (c) 2011, 2017, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
*
- * Lustre is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * lustre/lustre/llite/rw26.c
*
- * You should have received a copy of the GNU General Public License
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * Lustre Lite I/O page cache routines for the 2.5/2.6 kernel version
*/
-#include <linux/config.h>
+#include <linux/buffer_head.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
+#include <linux/mpage.h>
+#include <linux/pagemap.h>
#include <linux/string.h>
-#include <linux/stat.h>
-#include <linux/errno.h>
-#include <linux/smp_lock.h>
#include <linux/unistd.h>
-#include <linux/version.h>
-#include <asm/system.h>
-#include <asm/uaccess.h>
-
-#include <linux/fs.h>
-#include <linux/buffer_head.h>
-#include <linux/mpage.h>
#include <linux/writeback.h>
-#include <linux/stat.h>
-#include <asm/uaccess.h>
-#include <asm/segment.h>
-#include <linux/mm.h>
-#include <linux/pagemap.h>
-#include <linux/smp_lock.h>
+#include <linux/migrate.h>
#define DEBUG_SUBSYSTEM S_LLITE
-#include <linux/lustre_mds.h>
-#include <linux/lustre_lite.h>
#include "llite_internal.h"
-#include <linux/lustre_compat25.h>
+#include <lustre_compat.h>
-/* called for each page in a completed rpc.*/
-void ll_ap_completion_26(void *data, int cmd, int rc)
+/**
+ * Implements Linux VM address_space::invalidatepage() method. This method is
+ * called when the page is truncate from a file, either as a result of
+ * explicit truncate, or when inode is removed from memory (as a result of
+ * final iput(), umount, or memory pressure induced icache shrinking).
+ *
+ * [0, offset] bytes of the page remain valid (this is for a case of not-page
+ * aligned truncate). Lustre leaves partially truncated page in the cache,
+ * relying on struct inode::i_size to limit further accesses.
+ */
+static void ll_invalidatepage(struct page *vmpage,
+#ifdef HAVE_INVALIDATE_RANGE
+ unsigned int offset, unsigned int length
+#else
+ unsigned long offset
+#endif
+ )
{
- struct ll_async_page *llap;
- struct page *page;
+ struct inode *inode;
+ struct lu_env *env;
+ struct cl_page *page;
+ struct cl_object *obj;
- llap = llap_from_cookie(data);
- if (IS_ERR(llap)) {
- EXIT;
- return;
- }
+ LASSERT(PageLocked(vmpage));
+ LASSERT(!PageWriteback(vmpage));
+
+ /*
+ * It is safe to not check anything in invalidatepage/releasepage
+ * below because they are run with page locked and all our io is
+ * happening with locked page too
+ */
+#ifdef HAVE_INVALIDATE_RANGE
+ if (offset == 0 && length == PAGE_SIZE) {
+#else
+ if (offset == 0) {
+#endif
+ /* See the comment in ll_releasepage() */
+ env = cl_env_percpu_get();
+ LASSERT(!IS_ERR(env));
+
+ inode = vmpage->mapping->host;
+ obj = ll_i2info(inode)->lli_clob;
+ if (obj != NULL) {
+ page = cl_vmpage_page(vmpage, obj);
+ if (page != NULL) {
+ cl_page_delete(env, page);
+ cl_page_put(env, page);
+ }
+ } else
+ LASSERT(vmpage->private == 0);
- page = llap->llap_page;
- LASSERT(PageLocked(page));
-
- if (rc == 0) {
- if (cmd == OBD_BRW_READ) {
- if (!llap->llap_defer_uptodate)
- SetPageUptodate(page);
- } else {
- llap->llap_write_queued = 0;
- }
- } else {
- SetPageError(page);
+ cl_env_percpu_put(env);
}
+}
- LL_CDEBUG_PAGE(D_PAGE, page, "io complete, unlocking\n");
+#ifdef HAVE_RELEASEPAGE_WITH_INT
+#define RELEASEPAGE_ARG_TYPE int
+#else
+#define RELEASEPAGE_ARG_TYPE gfp_t
+#endif
+static int ll_releasepage(struct page *vmpage, RELEASEPAGE_ARG_TYPE gfp_mask)
+{
+ struct lu_env *env;
+ struct cl_object *obj;
+ struct cl_page *page;
+ struct address_space *mapping;
+ int result = 0;
- unlock_page(page);
+ LASSERT(PageLocked(vmpage));
+ if (PageWriteback(vmpage) || PageDirty(vmpage))
+ return 0;
- if (0 && cmd == OBD_BRW_WRITE) {
- llap_write_complete(page->mapping->host, llap);
- ll_try_done_writing(page->mapping->host);
- }
+ mapping = vmpage->mapping;
+ if (mapping == NULL)
+ return 1;
+
+ obj = ll_i2info(mapping->host)->lli_clob;
+ if (obj == NULL)
+ return 1;
+
+ page = cl_vmpage_page(vmpage, obj);
+ if (page == NULL)
+ return 1;
+
+ env = cl_env_percpu_get();
+ LASSERT(!IS_ERR(env));
+
+ if (!cl_page_in_use(page)) {
+ result = 1;
+ cl_page_delete(env, page);
+ }
+
+ /* To use percpu env array, the call path can not be rescheduled;
+ * otherwise percpu array will be messed if ll_releaspage() called
+ * again on the same CPU.
+ *
+ * If this page holds the last refc of cl_object, the following
+ * call path may cause reschedule:
+ * cl_page_put -> cl_page_free -> cl_object_put ->
+ * lu_object_put -> lu_object_free -> lov_delete_raid0.
+ *
+ * However, the kernel can't get rid of this inode until all pages have
+ * been cleaned up. Now that we hold page lock here, it's pretty safe
+ * that we won't get into object delete path.
+ */
+ LASSERT(cl_object_refc(obj) > 1);
+ cl_page_put(env, page);
+
+ cl_env_percpu_put(env);
+ return result;
+}
+
+#if defined(HAVE_DIRECTIO_ITER) || defined(HAVE_IOV_ITER_RW) || \
+ defined(HAVE_DIRECTIO_2ARGS)
+#define HAVE_DIO_ITER 1
+#endif
+
+/*
+ * ll_free_user_pages - tear down page struct array
+ * @pages: array of page struct pointers underlying target buffer
+ */
+static void ll_free_user_pages(struct page **pages, int npages)
+{
+ int i;
+
+ for (i = 0; i < npages; i++) {
+ if (!pages[i])
+ break;
+ put_page(pages[i]);
+ }
+
+#if defined(HAVE_DIO_ITER)
+ kvfree(pages);
+#else
+ OBD_FREE_PTR_ARRAY_LARGE(pages, npages);
+#endif
+}
+
+static ssize_t ll_get_user_pages(int rw, struct iov_iter *iter,
+ struct page ***pages, ssize_t *npages,
+ size_t maxsize)
+{
+#if defined(HAVE_DIO_ITER)
+ size_t start;
+ size_t result;
+
+ /*
+ * iov_iter_get_pages_alloc() is introduced in 3.16 similar
+ * to HAVE_DIO_ITER.
+ */
+ result = iov_iter_get_pages_alloc(iter, pages, maxsize, &start);
+ if (result > 0)
+ *npages = DIV_ROUND_UP(result + start, PAGE_SIZE);
+
+ return result;
+#else
+ unsigned long addr;
+ size_t page_count;
+ size_t size;
+ long result;
+
+ if (!maxsize)
+ return 0;
+
+ if (!iter->nr_segs)
+ return 0;
+
+ addr = (unsigned long)iter->iov->iov_base + iter->iov_offset;
+ if (addr & ~PAGE_MASK)
+ return -EINVAL;
+
+ size = min_t(size_t, maxsize, iter->iov->iov_len);
+ page_count = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ OBD_ALLOC_PTR_ARRAY_LARGE(*pages, page_count);
+ if (*pages == NULL)
+ return -ENOMEM;
+
+ down_read(¤t->mm->mmap_sem);
+ result = get_user_pages(current, current->mm, addr, page_count,
+ rw == READ, 0, *pages, NULL);
+ up_read(¤t->mm->mmap_sem);
+
+ if (unlikely(result != page_count)) {
+ ll_free_user_pages(*pages, page_count);
+ *pages = NULL;
+
+ if (result >= 0)
+ return -EFAULT;
+
+ return result;
+ }
+ *npages = page_count;
+
+ return size;
+#endif
+}
+
+/* iov_iter_alignment() is introduced in 3.16 similar to HAVE_DIO_ITER */
+#if defined(HAVE_DIO_ITER)
+static unsigned long ll_iov_iter_alignment(const struct iov_iter *i)
+{
+ return iov_iter_alignment(i);
+}
+#else /* copied from alignment_iovec() */
+static unsigned long ll_iov_iter_alignment(const struct iov_iter *i)
+{
+ const struct iovec *iov = i->iov;
+ unsigned long res;
+ size_t size = i->count;
+ size_t n;
+
+ if (!size)
+ return 0;
+
+ res = (unsigned long)iov->iov_base + i->iov_offset;
+ n = iov->iov_len - i->iov_offset;
+ if (n >= size)
+ return res | size;
+
+ size -= n;
+ res |= n;
+ while (size > (++iov)->iov_len) {
+ res |= (unsigned long)iov->iov_base | iov->iov_len;
+ size -= iov->iov_len;
+ }
+ res |= (unsigned long)iov->iov_base | size;
+
+ return res;
+}
+#endif
+
+/** direct IO pages */
+struct ll_dio_pages {
+ struct cl_dio_aio *ldp_aio;
+ /*
+ * page array to be written. we don't support
+ * partial pages except the last one.
+ */
+ struct page **ldp_pages;
+ /** # of pages in the array. */
+ size_t ldp_count;
+ /* the file offset of the first page. */
+ loff_t ldp_file_offset;
+};
+
+static int
+ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io, size_t size,
+ int rw, struct inode *inode, struct ll_dio_pages *pv)
+{
+ struct cl_page *page;
+ struct cl_2queue *queue = &io->ci_queue;
+ struct cl_object *obj = io->ci_obj;
+ struct cl_sync_io *anchor = &pv->ldp_aio->cda_sync;
+ loff_t offset = pv->ldp_file_offset;
+ int io_pages = 0;
+ size_t page_size = cl_page_size(obj);
+ int i;
+ ssize_t rc = 0;
+
+ ENTRY;
+
+ cl_2queue_init(queue);
+ for (i = 0; i < pv->ldp_count; i++) {
+ LASSERT(!(offset & (PAGE_SIZE - 1)));
+ page = cl_page_find(env, obj, cl_index(obj, offset),
+ pv->ldp_pages[i], CPT_TRANSIENT);
+ if (IS_ERR(page)) {
+ rc = PTR_ERR(page);
+ break;
+ }
+ LASSERT(page->cp_type == CPT_TRANSIENT);
+ rc = cl_page_own(env, io, page);
+ if (rc) {
+ cl_page_put(env, page);
+ break;
+ }
+
+ page->cp_sync_io = anchor;
+ cl_2queue_add(queue, page);
+ /*
+ * Set page clip to tell transfer formation engine
+ * that page has to be sent even if it is beyond KMS.
+ */
+ cl_page_clip(env, page, 0, min(size, page_size));
+ ++io_pages;
+
+ /* drop the reference count for cl_page_find */
+ cl_page_put(env, page);
+ offset += page_size;
+ size -= page_size;
+ }
+ if (rc == 0 && io_pages > 0) {
+ int iot = rw == READ ? CRT_READ : CRT_WRITE;
+
+ atomic_add(io_pages, &anchor->csi_sync_nr);
+ rc = cl_io_submit_rw(env, io, iot, queue);
+ if (rc == 0) {
+ cl_page_list_splice(&queue->c2_qout,
+ &pv->ldp_aio->cda_pages);
+ } else {
+ atomic_add(-queue->c2_qin.pl_nr,
+ &anchor->csi_sync_nr);
+ cl_page_list_for_each(page, &queue->c2_qin)
+ page->cp_sync_io = NULL;
+ }
+ /* handle partially submitted reqs */
+ if (queue->c2_qin.pl_nr > 0) {
+ CERROR(DFID " failed to submit %d dio pages: %zd\n",
+ PFID(lu_object_fid(&obj->co_lu)),
+ queue->c2_qin.pl_nr, rc);
+ if (rc == 0)
+ rc = -EIO;
+ }
+ }
+
+ cl_2queue_discard(env, io, queue);
+ cl_2queue_disown(env, io, queue);
+ cl_2queue_fini(env, queue);
+ RETURN(rc);
+}
+
+#ifdef KMALLOC_MAX_SIZE
+#define MAX_MALLOC KMALLOC_MAX_SIZE
+#else
+#define MAX_MALLOC (128 * 1024)
+#endif
+
+/* This is the maximum size of a single O_DIRECT request, based on the
+ * kmalloc limit. We need to fit all of the brw_page structs, each one
+ * representing PAGE_SIZE worth of user data, into a single buffer, and
+ * then truncate this to be a full-sized RPC. For 4kB PAGE_SIZE this is
+ * up to 22MB for 128kB kmalloc and up to 682MB for 4MB kmalloc. */
+#define MAX_DIO_SIZE ((MAX_MALLOC / sizeof(struct brw_page) * PAGE_SIZE) & \
+ ~((size_t)DT_MAX_BRW_SIZE - 1))
+
+static ssize_t
+ll_direct_IO_impl(struct kiocb *iocb, struct iov_iter *iter, int rw)
+{
+ struct ll_cl_context *lcc;
+ const struct lu_env *env;
+ struct cl_io *io;
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ struct cl_dio_aio *aio;
+ size_t count = iov_iter_count(iter);
+ ssize_t tot_bytes = 0, result = 0;
+ loff_t file_offset = iocb->ki_pos;
+
+ /* Check EOF by ourselves */
+ if (rw == READ && file_offset >= i_size_read(inode))
+ return 0;
+
+ /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
+ if ((file_offset & ~PAGE_MASK) || (count & ~PAGE_MASK))
+ return -EINVAL;
+
+ CDEBUG(D_VFSTRACE, "VFS Op:inode="DFID"(%p), size=%zd (max %lu), "
+ "offset=%lld=%llx, pages %zd (max %lu)\n",
+ PFID(ll_inode2fid(inode)), inode, count, MAX_DIO_SIZE,
+ file_offset, file_offset, count >> PAGE_SHIFT,
+ MAX_DIO_SIZE >> PAGE_SHIFT);
+
+ /* Check that all user buffers are aligned as well */
+ if (ll_iov_iter_alignment(iter) & ~PAGE_MASK)
+ return -EINVAL;
+
+ lcc = ll_cl_find(file);
+ if (lcc == NULL)
+ RETURN(-EIO);
+
+ env = lcc->lcc_env;
+ LASSERT(!IS_ERR(env));
+ io = lcc->lcc_io;
+ LASSERT(io != NULL);
+
+ aio = cl_aio_alloc(iocb);
+ if (!aio)
+ RETURN(-ENOMEM);
+
+ /* 0. Need locking between buffered and direct access. and race with
+ * size changing by concurrent truncates and writes.
+ * 1. Need inode mutex to operate transient pages.
+ */
+ if (rw == READ)
+ inode_lock(inode);
+
+ while (iov_iter_count(iter)) {
+ struct ll_dio_pages pvec = { .ldp_aio = aio };
+ struct page **pages;
+
+ count = min_t(size_t, iov_iter_count(iter), MAX_DIO_SIZE);
+ if (rw == READ) {
+ if (file_offset >= i_size_read(inode))
+ break;
+
+ if (file_offset + count > i_size_read(inode))
+ count = i_size_read(inode) - file_offset;
+ }
+
+ result = ll_get_user_pages(rw, iter, &pages,
+ &pvec.ldp_count, count);
+ if (unlikely(result <= 0))
+ GOTO(out, result);
+
+ count = result;
+ pvec.ldp_file_offset = file_offset;
+ pvec.ldp_pages = pages;
+
+ result = ll_direct_rw_pages(env, io, count,
+ rw, inode, &pvec);
+ ll_free_user_pages(pages, pvec.ldp_count);
+
+ if (unlikely(result < 0))
+ GOTO(out, result);
+
+ iov_iter_advance(iter, count);
+ tot_bytes += count;
+ file_offset += count;
+ }
+
+out:
+ aio->cda_bytes = tot_bytes;
+ cl_sync_io_note(env, &aio->cda_sync, result);
+
+ if (is_sync_kiocb(iocb)) {
+ ssize_t rc2;
+
+ rc2 = cl_sync_io_wait(env, &aio->cda_sync, 0);
+ if (result == 0 && rc2)
+ result = rc2;
+
+ if (result == 0) {
+ struct vvp_io *vio = vvp_env_io(env);
+ /* no commit async for direct IO */
+ vio->u.write.vui_written += tot_bytes;
+ result = tot_bytes;
+ }
+ OBD_FREE_PTR(aio);
+
+ } else {
+ result = -EIOCBQUEUED;
+ }
+
+ if (rw == READ)
+ inode_unlock(inode);
+
+ return result;
+}
+
+#if defined(HAVE_DIO_ITER)
+static ssize_t ll_direct_IO(
+#ifndef HAVE_IOV_ITER_RW
+ int rw,
+#endif
+ struct kiocb *iocb, struct iov_iter *iter
+#ifndef HAVE_DIRECTIO_2ARGS
+ , loff_t file_offset
+#endif
+ )
+{
+ int nrw;
+
+#ifndef HAVE_IOV_ITER_RW
+ nrw = rw;
+#else
+ nrw = iov_iter_rw(iter);
+#endif
+
+ return ll_direct_IO_impl(iocb, iter, nrw);
+}
+
+#else /* !defined(HAVE_DIO_ITER) */
+
+static ssize_t
+ll_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
+ loff_t file_offset, unsigned long nr_segs)
+{
+ struct iov_iter iter;
+
+ iov_iter_init(&iter, iov, nr_segs, iov_length(iov, nr_segs), 0);
+ return ll_direct_IO_impl(iocb, &iter, rw);
+}
+
+#endif /* !defined(HAVE_DIO_ITER) */
+
+/**
+ * Prepare partially written-to page for a write.
+ * @pg is owned when passed in and disowned when it returns non-zero result to
+ * the caller.
+ */
+static int ll_prepare_partial_page(const struct lu_env *env, struct cl_io *io,
+ struct cl_page *pg, struct file *file)
+{
+ struct cl_attr *attr = vvp_env_thread_attr(env);
+ struct cl_object *obj = io->ci_obj;
+ struct vvp_page *vpg = cl_object_page_slice(obj, pg);
+ loff_t offset = cl_offset(obj, vvp_index(vpg));
+ int result;
+ ENTRY;
+
+ cl_object_attr_lock(obj);
+ result = cl_object_attr_get(env, obj, attr);
+ cl_object_attr_unlock(obj);
+ if (result) {
+ cl_page_disown(env, io, pg);
+ GOTO(out, result);
+ }
+
+ /*
+ * If are writing to a new page, no need to read old data.
+ * The extent locking will have updated the KMS, and for our
+ * purposes here we can treat it like i_size.
+ */
+ if (attr->cat_kms <= offset) {
+ char *kaddr = kmap_atomic(vpg->vpg_page);
+
+ memset(kaddr, 0, cl_page_size(obj));
+ kunmap_atomic(kaddr);
+ GOTO(out, result = 0);
+ }
+
+ if (vpg->vpg_defer_uptodate) {
+ vpg->vpg_ra_used = 1;
+ GOTO(out, result = 0);
+ }
+
+ result = ll_io_read_page(env, io, pg, file);
+ if (result)
+ GOTO(out, result);
+
+ /* ll_io_read_page() disowns the page */
+ result = cl_page_own(env, io, pg);
+ if (!result) {
+ if (!PageUptodate(cl_page_vmpage(pg))) {
+ cl_page_disown(env, io, pg);
+ result = -EIO;
+ }
+ } else if (result == -ENOENT) {
+ /* page was truncated */
+ result = -EAGAIN;
+ }
+ EXIT;
- page_cache_release(page);
-}
-
-static int ll_writepage_26(struct page *page, struct writeback_control *wbc)
-{
- struct inode *inode = page->mapping->host;
- struct obd_export *exp;
- struct ll_async_page *llap;
- int rc;
- ENTRY;
-
- LASSERT(!PageDirty(page));
- LASSERT(PageLocked(page));
-
- exp = ll_i2obdexp(inode);
- if (exp == NULL)
- GOTO(out, rc = -EINVAL);
-
- llap = llap_from_page(page);
- if (IS_ERR(llap))
- GOTO(out, rc = PTR_ERR(llap));
-
- page_cache_get(page);
- if (llap->llap_write_queued) {
- LL_CDEBUG_PAGE(D_PAGE, page, "marking urgent\n");
- rc = obd_set_async_flags(exp, ll_i2info(inode)->lli_smd, NULL,
- llap->llap_cookie,
- ASYNC_READY | ASYNC_URGENT);
- } else {
- llap->llap_write_queued = 1;
- rc = obd_queue_async_io(exp, ll_i2info(inode)->lli_smd, NULL,
- llap->llap_cookie, OBD_BRW_WRITE, 0, 0,
- 0, ASYNC_READY | ASYNC_URGENT);
- if (rc == 0)
- LL_CDEBUG_PAGE(D_PAGE, page, "mmap write queued\n");
- else
- llap->llap_write_queued = 0;
- }
- if (rc)
- page_cache_release(page);
out:
- if (rc)
- unlock_page(page);
- RETURN(rc);
-}
-
-struct address_space_operations ll_aops = {
- readpage: ll_readpage,
-// readpages: ll_readpages,
-// direct_IO: ll_direct_IO_26,
- writepage: ll_writepage_26,
- writepages: generic_writepages,
- set_page_dirty: __set_page_dirty_nobuffers,
- sync_page: ll_sync_page,
- prepare_write: ll_prepare_write,
- commit_write: ll_commit_write,
- removepage: ll_removepage,
- bmap: NULL
+ return result;
+}
+
+static int ll_tiny_write_begin(struct page *vmpage, struct address_space *mapping)
+{
+ /* Page must be present, up to date, dirty, and not in writeback. */
+ if (!vmpage || !PageUptodate(vmpage) || !PageDirty(vmpage) ||
+ PageWriteback(vmpage) || vmpage->mapping != mapping)
+ return -ENODATA;
+
+ return 0;
+}
+
+static int ll_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct ll_cl_context *lcc = NULL;
+ const struct lu_env *env = NULL;
+ struct cl_io *io = NULL;
+ struct cl_page *page = NULL;
+
+ struct cl_object *clob = ll_i2info(mapping->host)->lli_clob;
+ pgoff_t index = pos >> PAGE_SHIFT;
+ struct page *vmpage = NULL;
+ unsigned from = pos & (PAGE_SIZE - 1);
+ unsigned to = from + len;
+ int result = 0;
+ ENTRY;
+
+ CDEBUG(D_VFSTRACE, "Writing %lu of %d to %d bytes\n", index, from, len);
+
+ lcc = ll_cl_find(file);
+ if (lcc == NULL) {
+ vmpage = grab_cache_page_nowait(mapping, index);
+ result = ll_tiny_write_begin(vmpage, mapping);
+ GOTO(out, result);
+ }
+
+ env = lcc->lcc_env;
+ io = lcc->lcc_io;
+
+ if (file->f_flags & O_DIRECT) {
+ /* direct IO failed because it couldn't clean up cached pages,
+ * this causes a problem for mirror write because the cached
+ * page may belong to another mirror, which will result in
+ * problem submitting the I/O. */
+ if (io->ci_designated_mirror > 0)
+ GOTO(out, result = -EBUSY);
+
+ /**
+ * Direct read can fall back to buffered read, but DIO is done
+ * with lockless i/o, and buffered requires LDLM locking, so
+ * in this case we must restart without lockless.
+ */
+ if (!io->ci_ignore_lockless) {
+ io->ci_ignore_lockless = 1;
+ io->ci_need_restart = 1;
+ GOTO(out, result = -ENOLCK);
+ }
+ }
+again:
+ /* To avoid deadlock, try to lock page first. */
+ vmpage = grab_cache_page_nowait(mapping, index);
+
+ if (unlikely(vmpage == NULL ||
+ PageDirty(vmpage) || PageWriteback(vmpage))) {
+ struct vvp_io *vio = vvp_env_io(env);
+ struct cl_page_list *plist = &vio->u.write.vui_queue;
+
+ /* if the page is already in dirty cache, we have to commit
+ * the pages right now; otherwise, it may cause deadlock
+ * because it holds page lock of a dirty page and request for
+ * more grants. It's okay for the dirty page to be the first
+ * one in commit page list, though. */
+ if (vmpage != NULL && plist->pl_nr > 0) {
+ unlock_page(vmpage);
+ put_page(vmpage);
+ vmpage = NULL;
+ }
+
+ /* commit pages and then wait for page lock */
+ result = vvp_io_write_commit(env, io);
+ if (result < 0)
+ GOTO(out, result);
+
+ if (vmpage == NULL) {
+ vmpage = grab_cache_page_write_begin(mapping, index,
+ flags);
+ if (vmpage == NULL)
+ GOTO(out, result = -ENOMEM);
+ }
+ }
+
+ /* page was truncated */
+ if (mapping != vmpage->mapping) {
+ CDEBUG(D_VFSTRACE, "page: %lu was truncated\n", index);
+ unlock_page(vmpage);
+ put_page(vmpage);
+ vmpage = NULL;
+ goto again;
+ }
+
+ page = cl_page_find(env, clob, vmpage->index, vmpage, CPT_CACHEABLE);
+ if (IS_ERR(page))
+ GOTO(out, result = PTR_ERR(page));
+
+ lcc->lcc_page = page;
+ lu_ref_add(&page->cp_reference, "cl_io", io);
+
+ cl_page_assume(env, io, page);
+ if (!PageUptodate(vmpage)) {
+ /*
+ * We're completely overwriting an existing page,
+ * so _don't_ set it up to date until commit_write
+ */
+ if (from == 0 && to == PAGE_SIZE) {
+ CL_PAGE_HEADER(D_PAGE, env, page, "full page write\n");
+ POISON_PAGE(vmpage, 0x11);
+ } else {
+ /* TODO: can be optimized at OSC layer to check if it
+ * is a lockless IO. In that case, it's not necessary
+ * to read the data. */
+ result = ll_prepare_partial_page(env, io, page, file);
+ if (result) {
+ /* vmpage should have been unlocked */
+ put_page(vmpage);
+ vmpage = NULL;
+
+ if (result == -EAGAIN)
+ goto again;
+ GOTO(out, result);
+ }
+ }
+ }
+ EXIT;
+out:
+ if (result < 0) {
+ if (vmpage != NULL) {
+ unlock_page(vmpage);
+ put_page(vmpage);
+ }
+ /* On tiny_write failure, page and io are always null. */
+ if (!IS_ERR_OR_NULL(page)) {
+ lu_ref_del(&page->cp_reference, "cl_io", io);
+ cl_page_put(env, page);
+ }
+ if (io)
+ io->ci_result = result;
+ } else {
+ *pagep = vmpage;
+ *fsdata = lcc;
+ }
+ RETURN(result);
+}
+
+static int ll_tiny_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned int len, unsigned int copied,
+ struct page *vmpage)
+{
+ struct cl_page *clpage = (struct cl_page *) vmpage->private;
+ loff_t kms = pos+copied;
+ loff_t to = kms & (PAGE_SIZE-1) ? kms & (PAGE_SIZE-1) : PAGE_SIZE;
+ __u16 refcheck;
+ struct lu_env *env = cl_env_get(&refcheck);
+ int rc = 0;
+
+ ENTRY;
+
+ if (IS_ERR(env)) {
+ rc = PTR_ERR(env);
+ goto out;
+ }
+
+ /* This page is dirty in cache, so it should have a cl_page pointer
+ * set in vmpage->private.
+ */
+ LASSERT(clpage != NULL);
+
+ if (copied == 0)
+ goto out_env;
+
+ /* Update the underlying size information in the OSC/LOV objects this
+ * page is part of.
+ */
+ cl_page_touch(env, clpage, to);
+
+out_env:
+ cl_env_put(env, &refcheck);
+
+out:
+ /* Must return page unlocked. */
+ unlock_page(vmpage);
+
+ RETURN(rc);
+}
+
+static int ll_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *vmpage, void *fsdata)
+{
+ struct ll_cl_context *lcc = fsdata;
+ const struct lu_env *env;
+ struct cl_io *io;
+ struct vvp_io *vio;
+ struct cl_page *page;
+ unsigned from = pos & (PAGE_SIZE - 1);
+ bool unplug = false;
+ int result = 0;
+ ENTRY;
+
+ put_page(vmpage);
+
+ CDEBUG(D_VFSTRACE, "pos %llu, len %u, copied %u\n", pos, len, copied);
+
+ if (lcc == NULL) {
+ result = ll_tiny_write_end(file, mapping, pos, len, copied,
+ vmpage);
+ GOTO(out, result);
+ }
+
+ LASSERT(lcc != NULL);
+ env = lcc->lcc_env;
+ page = lcc->lcc_page;
+ io = lcc->lcc_io;
+ vio = vvp_env_io(env);
+
+ LASSERT(cl_page_is_owned(page, io));
+ if (copied > 0) {
+ struct cl_page_list *plist = &vio->u.write.vui_queue;
+
+ lcc->lcc_page = NULL; /* page will be queued */
+
+ /* Add it into write queue */
+ cl_page_list_add(plist, page);
+ if (plist->pl_nr == 1) /* first page */
+ vio->u.write.vui_from = from;
+ else
+ LASSERT(from == 0);
+ vio->u.write.vui_to = from + copied;
+
+ /* To address the deadlock in balance_dirty_pages() where
+ * this dirty page may be written back in the same thread. */
+ if (PageDirty(vmpage))
+ unplug = true;
+
+ /* We may have one full RPC, commit it soon */
+ if (plist->pl_nr >= PTLRPC_MAX_BRW_PAGES)
+ unplug = true;
+
+ CL_PAGE_DEBUG(D_VFSTRACE, env, page,
+ "queued page: %d.\n", plist->pl_nr);
+ } else {
+ cl_page_disown(env, io, page);
+
+ lcc->lcc_page = NULL;
+ lu_ref_del(&page->cp_reference, "cl_io", io);
+ cl_page_put(env, page);
+
+ /* page list is not contiguous now, commit it now */
+ unplug = true;
+ }
+ if (unplug || io->u.ci_wr.wr_sync)
+ result = vvp_io_write_commit(env, io);
+
+ if (result < 0)
+ io->ci_result = result;
+
+
+out:
+ RETURN(result >= 0 ? copied : result);
+}
+
+#ifdef CONFIG_MIGRATION
+static int ll_migratepage(struct address_space *mapping,
+ struct page *newpage, struct page *page,
+ enum migrate_mode mode)
+{
+ /* Always fail page migration until we have a proper implementation */
+ return -EIO;
+}
+#endif
+
+const struct address_space_operations ll_aops = {
+ .readpage = ll_readpage,
+ .direct_IO = ll_direct_IO,
+ .writepage = ll_writepage,
+ .writepages = ll_writepages,
+ .set_page_dirty = __set_page_dirty_nobuffers,
+ .write_begin = ll_write_begin,
+ .write_end = ll_write_end,
+ .invalidatepage = ll_invalidatepage,
+ .releasepage = (void *)ll_releasepage,
+#ifdef CONFIG_MIGRATION
+ .migratepage = ll_migratepage,
+#endif
};
git://git.whamcloud.com / fs / lustre-release.git / blobdiff