X-Git-Url: https://git.whamcloud.com/?a=blobdiff_plain;f=lustre%2Fllite%2Fllite_mmap.c;h=4126a833dcee0b39a8e7d498f4ed938204c343cc;hb=fbf5870b9848929d352460f1f005b79c0b5ccc5a;hp=b1c5620fed06e1f33c597cc2317035b57d8a7e9d;hpb=26eb27ce838c6d9281c1a8a73429e6ee836da997;p=fs%2Flustre-release.git diff --git a/lustre/llite/llite_mmap.c b/lustre/llite/llite_mmap.c index b1c5620..4126a83 100644 --- a/lustre/llite/llite_mmap.c +++ b/lustre/llite/llite_mmap.c @@ -1,22 +1,37 @@ /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- * vim:expandtab:shiftwidth=8:tabstop=8: * - * Copyright (c) 2001-2003 Cluster File Systems, Inc. + * GPL HEADER START * - * This file is part of Lustre, http://www.lustre.org. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * - * 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. + * 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. * - * 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. + * 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 - * along with Lustre; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * 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 2008 Sun Microsystems, Inc. All rights reserved + * Use is subject to license terms. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. */ #ifndef AUTOCONF_INCLUDED @@ -36,9 +51,6 @@ #include #include #include -#ifdef HAVE_SEGMENT_H -# include -#endif #include #include #include @@ -57,210 +69,10 @@ vma->vm_file->f_dentry->d_inode->i_ino, \ vma->vm_file->f_dentry->d_iname, ## arg); \ - -struct ll_lock_tree_node { - rb_node_t lt_node; - struct list_head lt_locked_item; - __u64 lt_oid; - ldlm_policy_data_t lt_policy; - struct lustre_handle lt_lockh; - ldlm_mode_t lt_mode; - struct inode *lt_inode; -}; - -int lt_get_mmap_locks(struct ll_lock_tree *tree, - unsigned long addr, size_t count); - struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address, int *type); -struct ll_lock_tree_node * ll_node_from_inode(struct inode *inode, __u64 start, - __u64 end, ldlm_mode_t mode) -{ - struct ll_lock_tree_node *node; - - OBD_ALLOC(node, sizeof(*node)); - if (node == NULL) - RETURN(ERR_PTR(-ENOMEM)); - - node->lt_inode = inode; - node->lt_oid = ll_i2info(inode)->lli_smd->lsm_object_id; - node->lt_policy.l_extent.start = start; - node->lt_policy.l_extent.end = end; - memset(&node->lt_lockh, 0, sizeof(node->lt_lockh)); - INIT_LIST_HEAD(&node->lt_locked_item); - node->lt_mode = mode; - - return node; -} - -int lt_compare(struct ll_lock_tree_node *one, struct ll_lock_tree_node *two) -{ - /* To avoid multiple fs deadlock */ - if (one->lt_inode->i_sb->s_dev < two->lt_inode->i_sb->s_dev) - return -1; - if (one->lt_inode->i_sb->s_dev > two->lt_inode->i_sb->s_dev) - return 1; - - if (one->lt_oid < two->lt_oid) - return -1; - if (one->lt_oid > two->lt_oid) - return 1; - - if (one->lt_policy.l_extent.end < two->lt_policy.l_extent.start) - return -1; - if (one->lt_policy.l_extent.start > two->lt_policy.l_extent.end) - return 1; - - return 0; /* they are the same object and overlap */ -} - -static void lt_merge(struct ll_lock_tree_node *dst, - struct ll_lock_tree_node *src) -{ - dst->lt_policy.l_extent.start = min(dst->lt_policy.l_extent.start, - src->lt_policy.l_extent.start); - dst->lt_policy.l_extent.end = max(dst->lt_policy.l_extent.end, - src->lt_policy.l_extent.end); - - /* XXX could be a real call to the dlm to find superset modes */ - if (src->lt_mode == LCK_PW && dst->lt_mode != LCK_PW) - dst->lt_mode = LCK_PW; -} - -static void lt_insert(struct ll_lock_tree *tree, - struct ll_lock_tree_node *node) -{ - struct ll_lock_tree_node *walk; - rb_node_t **p, *parent; - ENTRY; - -restart: - p = &tree->lt_root.rb_node; - parent = NULL; - while (*p) { - parent = *p; - walk = rb_entry(parent, struct ll_lock_tree_node, lt_node); - switch (lt_compare(node, walk)) { - case -1: - p = &(*p)->rb_left; - break; - case 1: - p = &(*p)->rb_right; - break; - case 0: - lt_merge(node, walk); - rb_erase(&walk->lt_node, &tree->lt_root); - OBD_FREE(walk, sizeof(*walk)); - goto restart; - break; - default: - LBUG(); - break; - } - } - rb_link_node(&node->lt_node, parent, p); - rb_insert_color(&node->lt_node, &tree->lt_root); - EXIT; -} - -static struct ll_lock_tree_node *lt_least_node(struct ll_lock_tree *tree) -{ - rb_node_t *rbnode; - struct ll_lock_tree_node *node = NULL; - - for ( rbnode = tree->lt_root.rb_node; rbnode != NULL; - rbnode = rbnode->rb_left) { - if (rbnode->rb_left == NULL) { - node = rb_entry(rbnode, struct ll_lock_tree_node, - lt_node); - break; - } - } - RETURN(node); -} - -int ll_tree_unlock(struct ll_lock_tree *tree) -{ - struct ll_lock_tree_node *node; - struct list_head *pos, *n; - struct inode *inode; - int rc = 0; - ENTRY; - - list_for_each_safe(pos, n, &tree->lt_locked_list) { - node = list_entry(pos, struct ll_lock_tree_node, - lt_locked_item); - - inode = node->lt_inode; - rc = ll_extent_unlock(tree->lt_fd, inode, - ll_i2info(inode)->lli_smd, node->lt_mode, - &node->lt_lockh); - if (rc != 0) { - /* XXX better message */ - CERROR("couldn't unlock %d\n", rc); - } - list_del(&node->lt_locked_item); - OBD_FREE(node, sizeof(*node)); - } - - while ((node = lt_least_node(tree))) { - rb_erase(&node->lt_node, &tree->lt_root); - OBD_FREE(node, sizeof(*node)); - } - - RETURN(rc); -} - -int ll_tree_lock(struct ll_lock_tree *tree, - struct ll_lock_tree_node *first_node, - const char *buf, size_t count, int ast_flags) -{ - struct ll_lock_tree_node *node; - int rc = 0; - ENTRY; - - tree->lt_root.rb_node = NULL; - INIT_LIST_HEAD(&tree->lt_locked_list); - if (first_node != NULL) - lt_insert(tree, first_node); - - /* To avoid such subtle deadlock case: client1 try to read file1 to - * mmapped file2, on the same time, client2 try to read file2 to - * mmapped file1.*/ - rc = lt_get_mmap_locks(tree, (unsigned long)buf, count); - if (rc) - GOTO(out, rc); - - while ((node = lt_least_node(tree))) { - struct inode *inode = node->lt_inode; - rc = ll_extent_lock(tree->lt_fd, inode, - ll_i2info(inode)->lli_smd, node->lt_mode, - &node->lt_policy, &node->lt_lockh, - ast_flags); - if (rc != 0) - GOTO(out, rc); - - rb_erase(&node->lt_node, &tree->lt_root); - list_add_tail(&node->lt_locked_item, &tree->lt_locked_list); - } - RETURN(rc); -out: - ll_tree_unlock(tree); - RETURN(rc); -} - -static ldlm_mode_t mode_from_vma(struct vm_area_struct *vma) -{ - /* we only want to hold PW locks if the mmap() can generate - * writes back to the file and that only happens in shared - * writable vmas */ - if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE)) - return LCK_PW; - return LCK_PR; -} - -static void policy_from_vma(ldlm_policy_data_t *policy, +void policy_from_vma(ldlm_policy_data_t *policy, struct vm_area_struct *vma, unsigned long addr, size_t count) { @@ -270,7 +82,7 @@ static void policy_from_vma(ldlm_policy_data_t *policy, ~CFS_PAGE_MASK; } -static struct vm_area_struct * our_vma(unsigned long addr, size_t count) +struct vm_area_struct * our_vma(unsigned long addr, size_t count) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *ret = NULL; @@ -293,227 +105,133 @@ static struct vm_area_struct * our_vma(unsigned long addr, size_t count) RETURN(ret); } -int lt_get_mmap_locks(struct ll_lock_tree *tree, - unsigned long addr, size_t count) -{ - struct vm_area_struct *vma; - struct ll_lock_tree_node *node; - ldlm_policy_data_t policy; - struct inode *inode; - ENTRY; - - if (count == 0) - RETURN(0); - - /* we need to look up vmas on page aligned addresses */ - count += addr & (~CFS_PAGE_MASK); - addr &= CFS_PAGE_MASK; - - while ((vma = our_vma(addr, count)) != NULL) { - LASSERT(vma->vm_file); - - inode = vma->vm_file->f_dentry->d_inode; - policy_from_vma(&policy, vma, addr, count); - node = ll_node_from_inode(inode, policy.l_extent.start, - policy.l_extent.end, - mode_from_vma(vma)); - if (IS_ERR(node)) { - CERROR("not enough mem for lock_tree_node!\n"); - RETURN(-ENOMEM); - } - lt_insert(tree, node); - - if (vma->vm_end - addr >= count) - break; - count -= vma->vm_end - addr; - addr = vma->vm_end; - } - RETURN(0); -} - -/* FIXME: there is a pagefault race goes as follow (only 2.4): - * 1. A user process on node A accesses a portion of a mapped file, - * resulting in a page fault. The pagefault handler invokes the - * ll_nopage function, which reads the page into memory. - * 2. A user process on node B writes to the same portion of the file - * (either via mmap or write()), that cause node A to cancel the - * lock and truncate the page. - * 3. Node A then executes the rest of do_no_page(), entering the - * now-invalid page into the PTEs. +/** + * Lustre implementation of a vm_operations_struct::nopage() method, called by + * VM to server page fault (both in kernel and user space). + * + * This function sets up CIT_FAULT cl_io that does the job. * - * Make the whole do_no_page as a hook to cover both the page cache - * and page mapping installing with dlm lock would eliminate this race. + * \param vma - is virtiual area struct related to page fault + * \param address - address when hit fault + * \param type - of fault * - * In 2.6, the truncate_count of address_space can cover this race. + * XXX newer 2.6 kernels provide vm_operations_struct::fault() method with + * slightly different semantics instead. + * + * \return allocated and filled page for address + * \retval NOPAGE_SIGBUS if page not exist on this address + * \retval NOPAGE_OOM not have memory for allocate new page */ struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address, int *type) { - struct file *filp = vma->vm_file; - struct ll_file_data *fd = LUSTRE_FPRIVATE(filp); - struct inode *inode = filp->f_dentry->d_inode; - struct lustre_handle lockh = { 0 }; - ldlm_policy_data_t policy; - ldlm_mode_t mode; - struct page *page = NULL; - struct ll_inode_info *lli = ll_i2info(inode); - struct lov_stripe_md *lsm; - struct ost_lvb lvb; - __u64 kms, old_mtime; - unsigned long pgoff, size, rand_read, seq_read; - int rc = 0; - ENTRY; - - if (lli->lli_smd == NULL) { - CERROR("No lsm on fault?\n"); - RETURN(NULL); - } - - /* start and end the lock on the first and last bytes in the page */ - policy_from_vma(&policy, vma, address, CFS_PAGE_SIZE); + struct file *file = vma->vm_file; + struct inode *inode = file->f_dentry->d_inode; + struct lu_env *env; + struct cl_io *io; + struct page *page = NULL; + struct cl_env_nest nest; + int result; - CDEBUG(D_MMAP, "nopage vma %p inode %lu, locking ["LPU64", "LPU64"]\n", - vma, inode->i_ino, policy.l_extent.start, policy.l_extent.end); - - mode = mode_from_vma(vma); - old_mtime = LTIME_S(inode->i_mtime); - - lsm = lli->lli_smd; - rc = ll_extent_lock(fd, inode, lsm, mode, &policy, - &lockh, LDLM_FL_CBPENDING | LDLM_FL_NO_LRU); - if (rc != 0) - RETURN(NULL); - - if (vma->vm_flags & VM_EXEC && LTIME_S(inode->i_mtime) != old_mtime) - CWARN("binary changed. inode %lu\n", inode->i_ino); - - lov_stripe_lock(lsm); - inode_init_lvb(inode, &lvb); - obd_merge_lvb(ll_i2dtexp(inode), lsm, &lvb, 1); - kms = lvb.lvb_size; - - pgoff = ((address - vma->vm_start) >> CFS_PAGE_SHIFT) + vma->vm_pgoff; - size = (kms + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT; - - if (pgoff >= size) { - lov_stripe_unlock(lsm); - ll_glimpse_size(inode, LDLM_FL_BLOCK_GRANTED); - } else { - /* XXX change inode size without ll_inode_size_lock() held! - * there is a race condition with truncate path. (see - * ll_extent_lock) */ - /* XXX i_size_write() is not used because it is not safe to - * take the ll_inode_size_lock() due to a potential lock - * inversion (bug 6077). And since it's not safe to use - * i_size_write() without a covering mutex we do the - * assignment directly. It is not critical that the - * size be correct. */ - /* region is within kms and, hence, within real file size (A). - * We need to increase i_size to cover the read region so that - * generic_file_read() will do its job, but that doesn't mean - * the kms size is _correct_, it is only the _minimum_ size. - * If someone does a stat they will get the correct size which - * will always be >= the kms value here. b=11081 */ - if (i_size_read(inode) < kms) { - inode->i_size = kms; - CDEBUG(D_INODE, "ino=%lu, updating i_size %llu\n", - inode->i_ino, i_size_read(inode)); - } - lov_stripe_unlock(lsm); - } + ENTRY; - /* If mapping is writeable, adjust kms to cover this page, - * but do not extend kms beyond actual file size. - * policy.l_extent.end is set to the end of the page by policy_from_vma - * bug 10919 */ - lov_stripe_lock(lsm); - if (mode == LCK_PW) - obd_adjust_kms(ll_i2dtexp(inode), lsm, - min_t(loff_t, policy.l_extent.end + 1, - i_size_read(inode)), 0); - lov_stripe_unlock(lsm); - - /* 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. + /* + * vm_operations_struct::nopage() 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. */ - rand_read = vma->vm_flags & VM_RAND_READ; - seq_read = vma->vm_flags & VM_SEQ_READ; - vma->vm_flags &= ~ VM_SEQ_READ; - vma->vm_flags |= VM_RAND_READ; - - page = filemap_nopage(vma, address, type); - LL_CDEBUG_PAGE(D_PAGE, page, "got addr %lu type %lx\n", address, - (long)type); - vma->vm_flags &= ~VM_RAND_READ; - vma->vm_flags |= (rand_read | seq_read); - - ll_extent_unlock(fd, inode, ll_i2info(inode)->lli_smd, mode, &lockh); + env = cl_env_nested_get(&nest); + if (!IS_ERR(env)) { + pgoff_t pg_offset; + const unsigned long writable = VM_SHARED|VM_WRITE; + unsigned long ra_flags; + struct cl_fault_io *fio; + + io = &ccc_env_info(env)->cti_io; + io->ci_obj = ll_i2info(inode)->lli_clob; + LASSERT(io->ci_obj != NULL); + + fio = &io->u.ci_fault; + pg_offset = (address - vma->vm_start) >> PAGE_SHIFT; + fio->ft_index = pg_offset + vma->vm_pgoff; + fio->ft_writable = (vma->vm_flags&writable) == writable; + 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. + */ + 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_INFO, "vm_flags: %lx (%lu %i %i)\n", vma->vm_flags, + fio->ft_index, fio->ft_writable, fio->ft_executable); + + if (cl_io_init(env, io, CIT_FAULT, io->ci_obj) == 0) { + struct vvp_io *vio = vvp_env_io(env); + struct ccc_io *cio = ccc_env_io(env); + + LASSERT(cio->cui_cl.cis_io == io); + + vio->u.fault.ft_vma = vma; + vio->u.fault.ft_address = address; + vio->u.fault.ft_type = type; + cio->cui_fd = LUSTRE_FPRIVATE(file); + + result = cl_io_loop(env, io); + if (result == 0) { + LASSERT(fio->ft_page != NULL); + page = cl_page_vmpage(env, fio->ft_page); + } else if (result == -EFAULT) { + page = NOPAGE_SIGBUS; + } else if (result == -ENOMEM) { + page = NOPAGE_OOM; + } + } else + result = io->ci_result; + + vma->vm_flags &= ~VM_RAND_READ; + vma->vm_flags |= ra_flags; + + cl_io_fini(env, io); + cl_env_nested_put(&nest, env); + } RETURN(page); } -/* To avoid cancel the locks covering mmapped region for lock cache pressure, - * we track the mapped vma count by lli_mmap_cnt. - * ll_vm_open(): when first vma is linked, split locks from lru. - * ll_vm_close(): when last vma is unlinked, join all this file's locks to lru. - * - * XXX we don't check the if the region of vma/lock for performance. +/** + * 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 = vma->vm_file->f_dentry->d_inode; - struct ll_inode_info *lli = ll_i2info(inode); - ENTRY; + struct inode *inode = vma->vm_file->f_dentry->d_inode; + struct ccc_object *vob = cl_inode2ccc(inode); + ENTRY; LASSERT(vma->vm_file); - - spin_lock(&lli->lli_lock); - LASSERT(atomic_read(&lli->lli_mmap_cnt) >= 0); - - atomic_inc(&lli->lli_mmap_cnt); - if (atomic_read(&lli->lli_mmap_cnt) == 1) { - struct lov_stripe_md *lsm = lli->lli_smd; - struct ll_sb_info *sbi = ll_i2sbi(inode); - int count; - - spin_unlock(&lli->lli_lock); - - if (!lsm) - return; - count = obd_join_lru(sbi->ll_dt_exp, lsm, 0); - VMA_DEBUG(vma, "split %d unused locks from lru\n", count); - } else { - spin_unlock(&lli->lli_lock); - } - + LASSERT(atomic_read(&vob->cob_mmap_cnt) >= 0); + atomic_inc(&vob->cob_mmap_cnt); + EXIT; } +/** + * Dual to ll_vm_open(). + */ static void ll_vm_close(struct vm_area_struct *vma) { - struct inode *inode = vma->vm_file->f_dentry->d_inode; - struct ll_inode_info *lli = ll_i2info(inode); - ENTRY; + struct inode *inode = vma->vm_file->f_dentry->d_inode; + struct ccc_object *vob = cl_inode2ccc(inode); + ENTRY; LASSERT(vma->vm_file); - - spin_lock(&lli->lli_lock); - LASSERT(atomic_read(&lli->lli_mmap_cnt) > 0); - - atomic_dec(&lli->lli_mmap_cnt); - if (atomic_read(&lli->lli_mmap_cnt) == 0) { - struct lov_stripe_md *lsm = lli->lli_smd; - struct ll_sb_info *sbi = ll_i2sbi(inode); - int count; - - spin_unlock(&lli->lli_lock); - - if (!lsm) - return; - count = obd_join_lru(sbi->ll_dt_exp, lsm, 1); - VMA_DEBUG(vma, "join %d unused locks to lru\n", count); - } else { - spin_unlock(&lli->lli_lock); - } + atomic_dec(&vob->cob_mmap_cnt); + LASSERT(atomic_read(&vob->cob_mmap_cnt) >= 0); + EXIT; } #ifndef HAVE_FILEMAP_POPULATE @@ -577,7 +295,7 @@ int ll_file_mmap(struct file * file, struct vm_area_struct * vma) vma->vm_ops = &ll_file_vm_ops; vma->vm_ops->open(vma); /* update the inode's size and mtime */ - rc = ll_glimpse_size(file->f_dentry->d_inode, 0); + rc = cl_glimpse_size(file->f_dentry->d_inode); } RETURN(rc);