| /* |
| * 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, 2015, 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_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 && 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); |
| |
| 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) |
| *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; |
| |
| 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) { |
| 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) { |
| put_page(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 are 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)) { /* unlucky */ |
| unlock_page(vmpage); |
| put_page(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_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; |
| } |