--- /dev/null
+/*
+ * GPL HEADER START
+ *
+ * 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).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/uaccess.h>
+
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+
+#define DEBUG_SUBSYSTEM S_LLITE
+
+#include "../include/lustre_lite.h"
+#include "llite_internal.h"
+#include "../include/linux/lustre_compat25.h"
+
+static const struct vm_operations_struct ll_file_vm_ops;
+
+void policy_from_vma(ldlm_policy_data_t *policy,
+ struct vm_area_struct *vma, unsigned long addr,
+ size_t count)
+{
+ policy->l_extent.start = ((addr - vma->vm_start) & CFS_PAGE_MASK) +
+ (vma->vm_pgoff << PAGE_CACHE_SHIFT);
+ policy->l_extent.end = (policy->l_extent.start + count - 1) |
+ ~CFS_PAGE_MASK;
+}
+
+struct vm_area_struct *our_vma(struct mm_struct *mm, unsigned long addr,
+ size_t count)
+{
+ struct vm_area_struct *vma, *ret = NULL;
+
+ /* mmap_sem must have been held by caller. */
+ LASSERT(!down_write_trylock(&mm->mmap_sem));
+
+ for (vma = find_vma(mm, addr);
+ vma != NULL && vma->vm_start < (addr + count); vma = vma->vm_next) {
+ if (vma->vm_ops && vma->vm_ops == &ll_file_vm_ops &&
+ vma->vm_flags & VM_SHARED) {
+ ret = vma;
+ break;
+ }
+ }
+ return ret;
+}
+
+/**
+ * API independent part for page fault initialization.
+ * \param vma - virtual memory area addressed to page fault
+ * \param env - corespondent lu_env to processing
+ * \param nest - nested level
+ * \param index - page index corespondent to fault.
+ * \parm ra_flags - vma readahead flags.
+ *
+ * \return allocated and initialized env for fault operation.
+ * \retval EINVAL if env can't allocated
+ * \return other error codes from cl_io_init.
+ */
+static struct cl_io *
+ll_fault_io_init(struct vm_area_struct *vma, struct lu_env **env_ret,
+ struct cl_env_nest *nest, pgoff_t index,
+ unsigned long *ra_flags)
+{
+ struct file *file = vma->vm_file;
+ struct inode *inode = file_inode(file);
+ struct cl_io *io;
+ struct cl_fault_io *fio;
+ struct lu_env *env;
+ int rc;
+
+ *env_ret = NULL;
+ if (ll_file_nolock(file))
+ return ERR_PTR(-EOPNOTSUPP);
+
+ /*
+ * page fault can be called when lustre IO is
+ * already active for the current thread, e.g., when doing read/write
+ * against user level buffer mapped from Lustre buffer. To avoid
+ * stomping on existing context, optionally force an allocation of a new
+ * one.
+ */
+ env = cl_env_nested_get(nest);
+ if (IS_ERR(env))
+ return ERR_PTR(-EINVAL);
+
+ *env_ret = env;
+
+ io = ccc_env_thread_io(env);
+ io->ci_obj = ll_i2info(inode)->lli_clob;
+ LASSERT(io->ci_obj != NULL);
+
+ fio = &io->u.ci_fault;
+ fio->ft_index = index;
+ fio->ft_executable = vma->vm_flags&VM_EXEC;
+
+ /*
+ * disable VM_SEQ_READ and use VM_RAND_READ to make sure that
+ * the kernel will not read other pages not covered by ldlm in
+ * filemap_nopage. we do our readahead in ll_readpage.
+ */
+ if (ra_flags != NULL)
+ *ra_flags = vma->vm_flags & (VM_RAND_READ|VM_SEQ_READ);
+ vma->vm_flags &= ~VM_SEQ_READ;
+ vma->vm_flags |= VM_RAND_READ;
+
+ CDEBUG(D_MMAP, "vm_flags: %lx (%lu %d)\n", vma->vm_flags,
+ fio->ft_index, fio->ft_executable);
+
+ rc = cl_io_init(env, io, CIT_FAULT, io->ci_obj);
+ if (rc == 0) {
+ struct ccc_io *cio = ccc_env_io(env);
+ struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+
+ LASSERT(cio->cui_cl.cis_io == io);
+
+ /* mmap lock must be MANDATORY it has to cache
+ * pages. */
+ io->ci_lockreq = CILR_MANDATORY;
+ cio->cui_fd = fd;
+ } else {
+ LASSERT(rc < 0);
+ cl_io_fini(env, io);
+ cl_env_nested_put(nest, env);
+ io = ERR_PTR(rc);
+ }
+
+ return io;
+}
+
+/* Sharing code of page_mkwrite method for rhel5 and rhel6 */
+static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
+ bool *retry)
+{
+ struct lu_env *env;
+ struct cl_io *io;
+ struct vvp_io *vio;
+ struct cl_env_nest nest;
+ int result;
+ sigset_t set;
+ struct inode *inode;
+ struct ll_inode_info *lli;
+
+ LASSERT(vmpage != NULL);
+
+ io = ll_fault_io_init(vma, &env, &nest, vmpage->index, NULL);
+ if (IS_ERR(io)) {
+ result = PTR_ERR(io);
+ goto out;
+ }
+
+ result = io->ci_result;
+ if (result < 0)
+ goto out_io;
+
+ io->u.ci_fault.ft_mkwrite = 1;
+ io->u.ci_fault.ft_writable = 1;
+
+ vio = vvp_env_io(env);
+ vio->u.fault.ft_vma = vma;
+ vio->u.fault.ft_vmpage = vmpage;
+
+ set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));
+
+ /* we grab lli_trunc_sem to exclude truncate case.
+ * Otherwise, we could add dirty pages into osc cache
+ * while truncate is on-going. */
+ inode = ccc_object_inode(io->ci_obj);
+ lli = ll_i2info(inode);
+ down_read(&lli->lli_trunc_sem);
+
+ result = cl_io_loop(env, io);
+
+ up_read(&lli->lli_trunc_sem);
+
+ cfs_restore_sigs(set);
+
+ if (result == 0) {
+ struct inode *inode = file_inode(vma->vm_file);
+ struct ll_inode_info *lli = ll_i2info(inode);
+
+ lock_page(vmpage);
+ if (vmpage->mapping == NULL) {
+ unlock_page(vmpage);
+
+ /* page was truncated and lock was cancelled, return
+ * ENODATA so that VM_FAULT_NOPAGE will be returned
+ * to handle_mm_fault(). */
+ if (result == 0)
+ result = -ENODATA;
+ } else if (!PageDirty(vmpage)) {
+ /* race, the page has been cleaned by ptlrpcd after
+ * it was unlocked, it has to be added into dirty
+ * cache again otherwise this soon-to-dirty page won't
+ * consume any grants, even worse if this page is being
+ * transferred because it will break RPC checksum.
+ */
+ unlock_page(vmpage);
+
+ CDEBUG(D_MMAP, "Race on page_mkwrite %p/%lu, page has been written out, retry.\n",
+ vmpage, vmpage->index);
+
+ *retry = true;
+ result = -EAGAIN;
+ }
+
+ if (result == 0) {
+ spin_lock(&lli->lli_lock);
+ lli->lli_flags |= LLIF_DATA_MODIFIED;
+ spin_unlock(&lli->lli_lock);
+ }
+ }
+
+out_io:
+ cl_io_fini(env, io);
+ cl_env_nested_put(&nest, env);
+out:
+ CDEBUG(D_MMAP, "%s mkwrite with %d\n", current->comm, result);
+ LASSERT(ergo(result == 0, PageLocked(vmpage)));
+
+ return result;
+}
+
+
+
+static inline int to_fault_error(int result)
+{
+ switch (result) {
+ case 0:
+ result = VM_FAULT_LOCKED;
+ break;
+ case -EFAULT:
+ result = VM_FAULT_NOPAGE;
+ break;
+ case -ENOMEM:
+ result = VM_FAULT_OOM;
+ break;
+ default:
+ result = VM_FAULT_SIGBUS;
+ break;
+ }
+ return result;
+}
+
+/**
+ * Lustre implementation of a vm_operations_struct::fault() method, called by
+ * VM to server page fault (both in kernel and user space).
+ *
+ * \param vma - is virtual area struct related to page fault
+ * \param vmf - structure which describe type and address where hit fault
+ *
+ * \return allocated and filled _locked_ page for address
+ * \retval VM_FAULT_ERROR on general error
+ * \retval NOPAGE_OOM not have memory for allocate new page
+ */
+static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct lu_env *env;
+ struct cl_io *io;
+ struct vvp_io *vio = NULL;
+ struct page *vmpage;
+ unsigned long ra_flags;
+ struct cl_env_nest nest;
+ int result;
+ int fault_ret = 0;
+
+ io = ll_fault_io_init(vma, &env, &nest, vmf->pgoff, &ra_flags);
+ if (IS_ERR(io))
+ return to_fault_error(PTR_ERR(io));
+
+ result = io->ci_result;
+ if (result == 0) {
+ vio = vvp_env_io(env);
+ vio->u.fault.ft_vma = vma;
+ vio->u.fault.ft_vmpage = NULL;
+ vio->u.fault.fault.ft_vmf = vmf;
+ vio->u.fault.fault.ft_flags = 0;
+ vio->u.fault.fault.ft_flags_valid = false;
+
+ result = cl_io_loop(env, io);
+
+ /* ft_flags are only valid if we reached
+ * the call to filemap_fault */
+ if (vio->u.fault.fault.ft_flags_valid)
+ fault_ret = vio->u.fault.fault.ft_flags;
+
+ vmpage = vio->u.fault.ft_vmpage;
+ if (result != 0 && vmpage != NULL) {
+ page_cache_release(vmpage);
+ vmf->page = NULL;
+ }
+ }
+ cl_io_fini(env, io);
+ cl_env_nested_put(&nest, env);
+
+ vma->vm_flags |= ra_flags;
+ if (result != 0 && !(fault_ret & VM_FAULT_RETRY))
+ fault_ret |= to_fault_error(result);
+
+ CDEBUG(D_MMAP, "%s fault %d/%d\n",
+ current->comm, fault_ret, result);
+ return fault_ret;
+}
+
+static int ll_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ int count = 0;
+ bool printed = false;
+ int result;
+ sigset_t set;
+
+ /* Only SIGKILL and SIGTERM is allowed for fault/nopage/mkwrite
+ * so that it can be killed by admin but not cause segfault by
+ * other signals. */
+ set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));
+
+restart:
+ result = ll_fault0(vma, vmf);
+ LASSERT(!(result & VM_FAULT_LOCKED));
+ if (result == 0) {
+ struct page *vmpage = vmf->page;
+
+ /* check if this page has been truncated */
+ lock_page(vmpage);
+ if (unlikely(vmpage->mapping == NULL)) { /* unlucky */
+ unlock_page(vmpage);
+ page_cache_release(vmpage);
+ vmf->page = NULL;
+
+ if (!printed && ++count > 16) {
+ CWARN("the page is under heavy contention, maybe your app(%s) needs revising :-)\n",
+ current->comm);
+ printed = true;
+ }
+
+ goto restart;
+ }
+
+ result = VM_FAULT_LOCKED;
+ }
+ cfs_restore_sigs(set);
+ return result;
+}
+
+static int ll_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ int count = 0;
+ bool printed = false;
+ bool retry;
+ int result;
+
+ do {
+ retry = false;
+ result = ll_page_mkwrite0(vma, vmf->page, &retry);
+
+ if (!printed && ++count > 16) {
+ CWARN("app(%s): the page %lu of file %lu is under heavy contention.\n",
+ current->comm, vmf->pgoff,
+ file_inode(vma->vm_file)->i_ino);
+ printed = true;
+ }
+ } while (retry);
+
+ switch (result) {
+ case 0:
+ LASSERT(PageLocked(vmf->page));
+ result = VM_FAULT_LOCKED;
+ break;
+ case -ENODATA:
+ case -EFAULT:
+ result = VM_FAULT_NOPAGE;
+ break;
+ case -ENOMEM:
+ result = VM_FAULT_OOM;
+ break;
+ case -EAGAIN:
+ result = VM_FAULT_RETRY;
+ break;
+ default:
+ result = VM_FAULT_SIGBUS;
+ break;
+ }
+
+ return result;
+}
+
+/**
+ * To avoid cancel the locks covering mmapped region for lock cache pressure,
+ * we track the mapped vma count in ccc_object::cob_mmap_cnt.
+ */
+static void ll_vm_open(struct vm_area_struct *vma)
+{
+ struct inode *inode = file_inode(vma->vm_file);
+ struct ccc_object *vob = cl_inode2ccc(inode);
+
+ LASSERT(vma->vm_file);
+ LASSERT(atomic_read(&vob->cob_mmap_cnt) >= 0);
+ atomic_inc(&vob->cob_mmap_cnt);
+}
+
+/**
+ * Dual to ll_vm_open().
+ */
+static void ll_vm_close(struct vm_area_struct *vma)
+{
+ struct inode *inode = file_inode(vma->vm_file);
+ struct ccc_object *vob = cl_inode2ccc(inode);
+
+ LASSERT(vma->vm_file);
+ atomic_dec(&vob->cob_mmap_cnt);
+ LASSERT(atomic_read(&vob->cob_mmap_cnt) >= 0);
+}
+
+/* XXX put nice comment here. talk about __free_pte -> dirty pages and
+ * nopage's reference passing to the pte */
+int ll_teardown_mmaps(struct address_space *mapping, __u64 first, __u64 last)
+{
+ int rc = -ENOENT;
+
+ LASSERTF(last > first, "last %llu first %llu\n", last, first);
+ if (mapping_mapped(mapping)) {
+ rc = 0;
+ unmap_mapping_range(mapping, first + PAGE_CACHE_SIZE - 1,
+ last - first + 1, 0);
+ }
+
+ return rc;
+}
+
+static const struct vm_operations_struct ll_file_vm_ops = {
+ .fault = ll_fault,
+ .page_mkwrite = ll_page_mkwrite,
+ .open = ll_vm_open,
+ .close = ll_vm_close,
+};
+
+int ll_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct inode *inode = file_inode(file);
+ int rc;
+
+ if (ll_file_nolock(file))
+ return -EOPNOTSUPP;
+
+ ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_MAP, 1);
+ rc = generic_file_mmap(file, vma);
+ if (rc == 0) {
+ vma->vm_ops = &ll_file_vm_ops;
+ vma->vm_ops->open(vma);
+ /* update the inode's size and mtime */
+ rc = ll_glimpse_size(inode);
+ }
+
+ return rc;
+}
Code Review / kvmfornfv.git / blobdiff