1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
4 * Copyright (c) 2001-2003 Cluster File Systems, Inc.
6 * This file is part of Lustre, http://www.lustre.org.
8 * Lustre is free software; you can redistribute it and/or
9 * modify it under the terms of version 2 of the GNU General Public
10 * License as published by the Free Software Foundation.
12 * Lustre is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with Lustre; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #ifndef AUTOCONF_INCLUDED
23 #include <linux/config.h>
25 #include <linux/kernel.h>
27 #include <linux/string.h>
28 #include <linux/stat.h>
29 #include <linux/errno.h>
30 #include <linux/smp_lock.h>
31 #include <linux/unistd.h>
32 #include <linux/version.h>
33 #include <asm/system.h>
34 #include <asm/uaccess.h>
37 #include <linux/stat.h>
38 #include <asm/uaccess.h>
40 #include <linux/pagemap.h>
41 #include <linux/smp_lock.h>
43 #define DEBUG_SUBSYSTEM S_LLITE
45 //#include <lustre_mdc.h>
46 #include <lustre_lite.h>
47 #include "llite_internal.h"
48 #include <linux/lustre_compat25.h>
50 #define VMA_DEBUG(vma, fmt, arg...) \
51 CDEBUG(D_MMAP, "vma(%p) start(%ld) end(%ld) pgoff(%ld) inode(%p) " \
52 "ino(%lu) iname(%s): " fmt, vma, vma->vm_start, vma->vm_end, \
53 vma->vm_pgoff, vma->vm_file->f_dentry->d_inode, \
54 vma->vm_file->f_dentry->d_inode->i_ino, \
55 vma->vm_file->f_dentry->d_iname, ## arg); \
58 struct ll_lock_tree_node {
60 struct list_head lt_locked_item;
62 ldlm_policy_data_t lt_policy;
63 struct lustre_handle lt_lockh;
65 struct inode *lt_inode;
68 int lt_get_mmap_locks(struct ll_lock_tree *tree,
69 unsigned long addr, size_t count);
71 struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address,
74 struct ll_lock_tree_node * ll_node_from_inode(struct inode *inode, __u64 start,
75 __u64 end, ldlm_mode_t mode)
77 struct ll_lock_tree_node *node;
79 OBD_ALLOC(node, sizeof(*node));
81 RETURN(ERR_PTR(-ENOMEM));
83 node->lt_inode = inode;
84 node->lt_oid = ll_i2info(inode)->lli_smd->lsm_object_id;
85 node->lt_policy.l_extent.start = start;
86 node->lt_policy.l_extent.end = end;
87 memset(&node->lt_lockh, 0, sizeof(node->lt_lockh));
88 INIT_LIST_HEAD(&node->lt_locked_item);
94 int lt_compare(struct ll_lock_tree_node *one, struct ll_lock_tree_node *two)
96 /* To avoid multiple fs deadlock */
97 if (one->lt_inode->i_sb->s_dev < two->lt_inode->i_sb->s_dev)
99 if (one->lt_inode->i_sb->s_dev > two->lt_inode->i_sb->s_dev)
102 if (one->lt_oid < two->lt_oid)
104 if (one->lt_oid > two->lt_oid)
107 if (one->lt_policy.l_extent.end < two->lt_policy.l_extent.start)
109 if (one->lt_policy.l_extent.start > two->lt_policy.l_extent.end)
112 return 0; /* they are the same object and overlap */
115 static void lt_merge(struct ll_lock_tree_node *dst,
116 struct ll_lock_tree_node *src)
118 dst->lt_policy.l_extent.start = min(dst->lt_policy.l_extent.start,
119 src->lt_policy.l_extent.start);
120 dst->lt_policy.l_extent.end = max(dst->lt_policy.l_extent.end,
121 src->lt_policy.l_extent.end);
123 /* XXX could be a real call to the dlm to find superset modes */
124 if (src->lt_mode == LCK_PW && dst->lt_mode != LCK_PW)
125 dst->lt_mode = LCK_PW;
128 static void lt_insert(struct ll_lock_tree *tree,
129 struct ll_lock_tree_node *node)
131 struct ll_lock_tree_node *walk;
132 rb_node_t **p, *parent;
136 p = &tree->lt_root.rb_node;
140 walk = rb_entry(parent, struct ll_lock_tree_node, lt_node);
141 switch (lt_compare(node, walk)) {
149 lt_merge(node, walk);
150 rb_erase(&walk->lt_node, &tree->lt_root);
151 OBD_FREE(walk, sizeof(*walk));
159 rb_link_node(&node->lt_node, parent, p);
160 rb_insert_color(&node->lt_node, &tree->lt_root);
164 static struct ll_lock_tree_node *lt_least_node(struct ll_lock_tree *tree)
167 struct ll_lock_tree_node *node = NULL;
169 for ( rbnode = tree->lt_root.rb_node; rbnode != NULL;
170 rbnode = rbnode->rb_left) {
171 if (rbnode->rb_left == NULL) {
172 node = rb_entry(rbnode, struct ll_lock_tree_node,
180 int ll_tree_unlock(struct ll_lock_tree *tree)
182 struct ll_lock_tree_node *node;
183 struct list_head *pos, *n;
188 list_for_each_safe(pos, n, &tree->lt_locked_list) {
189 node = list_entry(pos, struct ll_lock_tree_node,
192 inode = node->lt_inode;
193 rc = ll_extent_unlock(tree->lt_fd, inode,
194 ll_i2info(inode)->lli_smd, node->lt_mode,
197 /* XXX better message */
198 CERROR("couldn't unlock %d\n", rc);
200 list_del(&node->lt_locked_item);
201 OBD_FREE(node, sizeof(*node));
204 while ((node = lt_least_node(tree))) {
205 rb_erase(&node->lt_node, &tree->lt_root);
206 OBD_FREE(node, sizeof(*node));
212 int ll_tree_lock(struct ll_lock_tree *tree,
213 struct ll_lock_tree_node *first_node,
214 const char *buf, size_t count, int ast_flags)
216 struct ll_lock_tree_node *node;
220 tree->lt_root.rb_node = NULL;
221 INIT_LIST_HEAD(&tree->lt_locked_list);
222 if (first_node != NULL)
223 lt_insert(tree, first_node);
225 /* To avoid such subtle deadlock case: client1 try to read file1 to
226 * mmapped file2, on the same time, client2 try to read file2 to
228 rc = lt_get_mmap_locks(tree, (unsigned long)buf, count);
232 while ((node = lt_least_node(tree))) {
233 struct inode *inode = node->lt_inode;
234 rc = ll_extent_lock(tree->lt_fd, inode,
235 ll_i2info(inode)->lli_smd, node->lt_mode,
236 &node->lt_policy, &node->lt_lockh,
241 rb_erase(&node->lt_node, &tree->lt_root);
242 list_add_tail(&node->lt_locked_item, &tree->lt_locked_list);
246 ll_tree_unlock(tree);
250 static ldlm_mode_t mode_from_vma(struct vm_area_struct *vma)
252 /* we only want to hold PW locks if the mmap() can generate
253 * writes back to the file and that only happens in shared
255 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE))
260 static void policy_from_vma(ldlm_policy_data_t *policy,
261 struct vm_area_struct *vma, unsigned long addr,
264 policy->l_extent.start = ((addr - vma->vm_start) & CFS_PAGE_MASK) +
265 (vma->vm_pgoff << CFS_PAGE_SHIFT);
266 policy->l_extent.end = (policy->l_extent.start + count - 1) |
270 static struct vm_area_struct * our_vma(unsigned long addr, size_t count)
272 struct mm_struct *mm = current->mm;
273 struct vm_area_struct *vma, *ret = NULL;
276 /* No MM (e.g. NFS)? No vmas too. */
280 spin_lock(&mm->page_table_lock);
281 for(vma = find_vma(mm, addr);
282 vma != NULL && vma->vm_start < (addr + count); vma = vma->vm_next) {
283 if (vma->vm_ops && vma->vm_ops->nopage == ll_nopage &&
284 vma->vm_flags & VM_SHARED) {
289 spin_unlock(&mm->page_table_lock);
293 int ll_region_mapped(unsigned long addr, size_t count)
295 return !!our_vma(addr, count);
298 int lt_get_mmap_locks(struct ll_lock_tree *tree,
299 unsigned long addr, size_t count)
301 struct vm_area_struct *vma;
302 struct ll_lock_tree_node *node;
303 ldlm_policy_data_t policy;
310 /* we need to look up vmas on page aligned addresses */
311 count += addr & (~CFS_PAGE_MASK);
312 addr &= CFS_PAGE_MASK;
314 while ((vma = our_vma(addr, count)) != NULL) {
315 LASSERT(vma->vm_file);
317 inode = vma->vm_file->f_dentry->d_inode;
318 policy_from_vma(&policy, vma, addr, count);
319 node = ll_node_from_inode(inode, policy.l_extent.start,
323 CERROR("not enough mem for lock_tree_node!\n");
326 lt_insert(tree, node);
328 if (vma->vm_end - addr >= count)
330 count -= vma->vm_end - addr;
337 * Page fault handler.
339 * \param vma - is virtiual area struct related to page fault
340 * \param address - address when hit fault
341 * \param type - of fault
343 * \return allocated and filled page for address
344 * \retval NOPAGE_SIGBUS if page not exist on this address
345 * \retval NOPAGE_OOM not have memory for allocate new page
347 struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address,
350 struct file *filp = vma->vm_file;
351 struct ll_file_data *fd = LUSTRE_FPRIVATE(filp);
352 struct inode *inode = filp->f_dentry->d_inode;
353 struct lustre_handle lockh = { 0 };
354 ldlm_policy_data_t policy;
356 struct page *page = NULL;
357 struct ll_inode_info *lli = ll_i2info(inode);
358 struct lov_stripe_md *lsm;
360 __u64 kms, old_mtime;
361 unsigned long pgoff, size, rand_read, seq_read;
365 if (lli->lli_smd == NULL) {
366 CERROR("No lsm on fault?\n");
370 ll_clear_file_contended(inode);
372 /* start and end the lock on the first and last bytes in the page */
373 policy_from_vma(&policy, vma, address, CFS_PAGE_SIZE);
375 CDEBUG(D_MMAP, "nopage vma %p inode %lu, locking ["LPU64", "LPU64"]\n",
376 vma, inode->i_ino, policy.l_extent.start, policy.l_extent.end);
378 mode = mode_from_vma(vma);
379 old_mtime = LTIME_S(inode->i_mtime);
382 rc = ll_extent_lock(fd, inode, lsm, mode, &policy,
383 &lockh, LDLM_FL_CBPENDING | LDLM_FL_NO_LRU);
387 if (vma->vm_flags & VM_EXEC && LTIME_S(inode->i_mtime) != old_mtime)
388 CWARN("binary changed. inode %lu\n", inode->i_ino);
390 lov_stripe_lock(lsm);
391 inode_init_lvb(inode, &lvb);
392 obd_merge_lvb(ll_i2dtexp(inode), lsm, &lvb, 1);
395 pgoff = ((address - vma->vm_start) >> CFS_PAGE_SHIFT) + vma->vm_pgoff;
396 size = (kms + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
399 lov_stripe_unlock(lsm);
400 ll_glimpse_size(inode, LDLM_FL_BLOCK_GRANTED);
402 /* XXX change inode size without ll_inode_size_lock() held!
403 * there is a race condition with truncate path. (see
405 /* XXX i_size_write() is not used because it is not safe to
406 * take the ll_inode_size_lock() due to a potential lock
407 * inversion (bug 6077). And since it's not safe to use
408 * i_size_write() without a covering mutex we do the
409 * assignment directly. It is not critical that the
410 * size be correct. */
411 /* region is within kms and, hence, within real file size (A).
412 * We need to increase i_size to cover the read region so that
413 * generic_file_read() will do its job, but that doesn't mean
414 * the kms size is _correct_, it is only the _minimum_ size.
415 * If someone does a stat they will get the correct size which
416 * will always be >= the kms value here. b=11081 */
417 if (i_size_read(inode) < kms) {
419 CDEBUG(D_INODE, "ino=%lu, updating i_size %llu\n",
420 inode->i_ino, i_size_read(inode));
422 lov_stripe_unlock(lsm);
425 /* If mapping is writeable, adjust kms to cover this page,
426 * but do not extend kms beyond actual file size.
427 * policy.l_extent.end is set to the end of the page by policy_from_vma
429 lov_stripe_lock(lsm);
431 obd_adjust_kms(ll_i2dtexp(inode), lsm,
432 min_t(loff_t, policy.l_extent.end + 1,
433 i_size_read(inode)), 0);
434 lov_stripe_unlock(lsm);
436 /* disable VM_SEQ_READ and use VM_RAND_READ to make sure that
437 * the kernel will not read other pages not covered by ldlm in
438 * filemap_nopage. we do our readahead in ll_readpage.
440 rand_read = vma->vm_flags & VM_RAND_READ;
441 seq_read = vma->vm_flags & VM_SEQ_READ;
442 vma->vm_flags &= ~ VM_SEQ_READ;
443 vma->vm_flags |= VM_RAND_READ;
445 page = filemap_nopage(vma, address, type);
446 if (page != NOPAGE_SIGBUS && page != NOPAGE_OOM)
447 LL_CDEBUG_PAGE(D_PAGE, page, "got addr %lu type %lx\n", address,
450 CDEBUG(D_PAGE, "got addr %lu type %lx - SIGBUS\n", address,
453 vma->vm_flags &= ~VM_RAND_READ;
454 vma->vm_flags |= (rand_read | seq_read);
456 ll_extent_unlock(fd, inode, ll_i2info(inode)->lli_smd, mode, &lockh);
460 /* To avoid cancel the locks covering mmapped region for lock cache pressure,
461 * we track the mapped vma count by lli_mmap_cnt.
462 * ll_vm_open(): when first vma is linked, split locks from lru.
463 * ll_vm_close(): when last vma is unlinked, join all this file's locks to lru.
465 * XXX we don't check the if the region of vma/lock for performance.
467 static void ll_vm_open(struct vm_area_struct * vma)
469 struct inode *inode = vma->vm_file->f_dentry->d_inode;
470 struct ll_inode_info *lli = ll_i2info(inode);
473 LASSERT(vma->vm_file);
475 spin_lock(&lli->lli_lock);
476 LASSERT(atomic_read(&lli->lli_mmap_cnt) >= 0);
478 atomic_inc(&lli->lli_mmap_cnt);
479 if (atomic_read(&lli->lli_mmap_cnt) == 1) {
480 struct lov_stripe_md *lsm = lli->lli_smd;
481 struct ll_sb_info *sbi = ll_i2sbi(inode);
484 spin_unlock(&lli->lli_lock);
488 count = obd_join_lru(sbi->ll_dt_exp, lsm, 0);
489 VMA_DEBUG(vma, "split %d unused locks from lru\n", count);
491 spin_unlock(&lli->lli_lock);
496 static void ll_vm_close(struct vm_area_struct *vma)
498 struct inode *inode = vma->vm_file->f_dentry->d_inode;
499 struct ll_inode_info *lli = ll_i2info(inode);
502 LASSERT(vma->vm_file);
504 spin_lock(&lli->lli_lock);
505 LASSERT(atomic_read(&lli->lli_mmap_cnt) > 0);
507 atomic_dec(&lli->lli_mmap_cnt);
508 if (atomic_read(&lli->lli_mmap_cnt) == 0) {
509 struct lov_stripe_md *lsm = lli->lli_smd;
510 struct ll_sb_info *sbi = ll_i2sbi(inode);
513 spin_unlock(&lli->lli_lock);
517 count = obd_join_lru(sbi->ll_dt_exp, lsm, 1);
518 VMA_DEBUG(vma, "join %d unused locks to lru\n", count);
520 spin_unlock(&lli->lli_lock);
524 #ifndef HAVE_FILEMAP_POPULATE
525 static int (*filemap_populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);
527 static int ll_populate(struct vm_area_struct *area, unsigned long address,
528 unsigned long len, pgprot_t prot, unsigned long pgoff,
534 /* always set nonblock as true to avoid page read ahead */
535 rc = filemap_populate(area, address, len, prot, pgoff, 1);
539 /* return the user space pointer that maps to a file offset via a vma */
540 static inline unsigned long file_to_user(struct vm_area_struct *vma, __u64 byte)
542 return vma->vm_start + (byte - ((__u64)vma->vm_pgoff << CFS_PAGE_SHIFT));
546 /* XXX put nice comment here. talk about __free_pte -> dirty pages and
547 * nopage's reference passing to the pte */
548 int ll_teardown_mmaps(struct address_space *mapping, __u64 first, __u64 last)
553 LASSERTF(last > first, "last "LPU64" first "LPU64"\n", last, first);
554 if (mapping_mapped(mapping)) {
556 unmap_mapping_range(mapping, first + CFS_PAGE_SIZE - 1,
557 last - first + 1, 0);
563 static struct vm_operations_struct ll_file_vm_ops = {
566 .close = ll_vm_close,
567 .populate = ll_populate,
570 int ll_file_mmap(struct file * file, struct vm_area_struct * vma)
575 ll_stats_ops_tally(ll_i2sbi(file->f_dentry->d_inode), LPROC_LL_MAP, 1);
576 rc = generic_file_mmap(file, vma);
578 #if !defined(HAVE_FILEMAP_POPULATE)
579 if (!filemap_populate)
580 filemap_populate = vma->vm_ops->populate;
582 vma->vm_ops = &ll_file_vm_ops;
583 vma->vm_ops->open(vma);
584 /* update the inode's size and mtime */
585 rc = ll_glimpse_size(file->f_dentry->d_inode, 0);