1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2011, 2012, Intel Corporation.
31 */
32 /*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 *
36 * lustre/lustre/llite/rw26.c
37 *
38 * Lustre Lite I/O page cache routines for the 2.5/2.6 kernel version
39 */
40
41 #include <linux/kernel.h>
42 #include <linux/mm.h>
43 #include <linux/string.h>
44 #include <linux/stat.h>
45 #include <linux/errno.h>
46 #include <linux/unistd.h>
47 #include <linux/uaccess.h>
48
49 #include <linux/migrate.h>
50 #include <linux/fs.h>
51 #include <linux/buffer_head.h>
52 #include <linux/mpage.h>
53 #include <linux/writeback.h>
54 #include <linux/pagemap.h>
55
56 #define DEBUG_SUBSYSTEM S_LLITE
57
58 #include "../include/lustre_lite.h"
59 #include "llite_internal.h"
60 #include "../include/linux/lustre_compat25.h"
61
62 /**
63 * Implements Linux VM address_space::invalidatepage() method. This method is
64 * called when the page is truncate from a file, either as a result of
65 * explicit truncate, or when inode is removed from memory (as a result of
66 * final iput(), umount, or memory pressure induced icache shrinking).
67 *
68 * [0, offset] bytes of the page remain valid (this is for a case of not-page
69 * aligned truncate). Lustre leaves partially truncated page in the cache,
70 * relying on struct inode::i_size to limit further accesses.
71 */
ll_invalidatepage(struct page * vmpage,unsigned int offset,unsigned int length)72 static void ll_invalidatepage(struct page *vmpage, unsigned int offset,
73 unsigned int length)
74 {
75 struct inode *inode;
76 struct lu_env *env;
77 struct cl_page *page;
78 struct cl_object *obj;
79
80 int refcheck;
81
82 LASSERT(PageLocked(vmpage));
83 LASSERT(!PageWriteback(vmpage));
84
85 /*
86 * It is safe to not check anything in invalidatepage/releasepage
87 * below because they are run with page locked and all our io is
88 * happening with locked page too
89 */
90 if (offset == 0 && length == PAGE_CACHE_SIZE) {
91 env = cl_env_get(&refcheck);
92 if (!IS_ERR(env)) {
93 inode = vmpage->mapping->host;
94 obj = ll_i2info(inode)->lli_clob;
95 if (obj != NULL) {
96 page = cl_vmpage_page(vmpage, obj);
97 if (page != NULL) {
98 lu_ref_add(&page->cp_reference,
99 "delete", vmpage);
100 cl_page_delete(env, page);
101 lu_ref_del(&page->cp_reference,
102 "delete", vmpage);
103 cl_page_put(env, page);
104 }
105 } else
106 LASSERT(vmpage->private == 0);
107 cl_env_put(env, &refcheck);
108 }
109 }
110 }
111
112 #ifdef HAVE_RELEASEPAGE_WITH_INT
113 #define RELEASEPAGE_ARG_TYPE int
114 #else
115 #define RELEASEPAGE_ARG_TYPE gfp_t
116 #endif
ll_releasepage(struct page * vmpage,RELEASEPAGE_ARG_TYPE gfp_mask)117 static int ll_releasepage(struct page *vmpage, RELEASEPAGE_ARG_TYPE gfp_mask)
118 {
119 struct cl_env_nest nest;
120 struct lu_env *env;
121 struct cl_object *obj;
122 struct cl_page *page;
123 struct address_space *mapping;
124 int result;
125
126 LASSERT(PageLocked(vmpage));
127 if (PageWriteback(vmpage) || PageDirty(vmpage))
128 return 0;
129
130 mapping = vmpage->mapping;
131 if (mapping == NULL)
132 return 1;
133
134 obj = ll_i2info(mapping->host)->lli_clob;
135 if (obj == NULL)
136 return 1;
137
138 /* 1 for page allocator, 1 for cl_page and 1 for page cache */
139 if (page_count(vmpage) > 3)
140 return 0;
141
142 /* TODO: determine what gfp should be used by @gfp_mask. */
143 env = cl_env_nested_get(&nest);
144 if (IS_ERR(env))
145 /* If we can't allocate an env we won't call cl_page_put()
146 * later on which further means it's impossible to drop
147 * page refcount by cl_page, so ask kernel to not free
148 * this page. */
149 return 0;
150
151 page = cl_vmpage_page(vmpage, obj);
152 result = page == NULL;
153 if (page != NULL) {
154 if (!cl_page_in_use(page)) {
155 result = 1;
156 cl_page_delete(env, page);
157 }
158 cl_page_put(env, page);
159 }
160 cl_env_nested_put(&nest, env);
161 return result;
162 }
163
ll_set_page_dirty(struct page * vmpage)164 static int ll_set_page_dirty(struct page *vmpage)
165 {
166 #if 0
167 struct cl_page *page = vvp_vmpage_page_transient(vmpage);
168 struct vvp_object *obj = cl_inode2vvp(vmpage->mapping->host);
169 struct vvp_page *cpg;
170
171 /*
172 * XXX should page method be called here?
173 */
174 LASSERT(&obj->co_cl == page->cp_obj);
175 cpg = cl2vvp_page(cl_page_at(page, &vvp_device_type));
176 /*
177 * XXX cannot do much here, because page is possibly not locked:
178 * sys_munmap()->...
179 * ->unmap_page_range()->zap_pte_range()->set_page_dirty().
180 */
181 vvp_write_pending(obj, cpg);
182 #endif
183 return __set_page_dirty_nobuffers(vmpage);
184 }
185
186 #define MAX_DIRECTIO_SIZE (2*1024*1024*1024UL)
187
ll_get_user_pages(int rw,unsigned long user_addr,size_t size,struct page *** pages,int * max_pages)188 static inline int ll_get_user_pages(int rw, unsigned long user_addr,
189 size_t size, struct page ***pages,
190 int *max_pages)
191 {
192 int result = -ENOMEM;
193
194 /* set an arbitrary limit to prevent arithmetic overflow */
195 if (size > MAX_DIRECTIO_SIZE) {
196 *pages = NULL;
197 return -EFBIG;
198 }
199
200 *max_pages = (user_addr + size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
201 *max_pages -= user_addr >> PAGE_CACHE_SHIFT;
202
203 *pages = libcfs_kvzalloc(*max_pages * sizeof(**pages), GFP_NOFS);
204 if (*pages) {
205 result = get_user_pages_fast(user_addr, *max_pages,
206 (rw == READ), *pages);
207 if (unlikely(result <= 0))
208 kvfree(*pages);
209 }
210
211 return result;
212 }
213
214 /* ll_free_user_pages - tear down page struct array
215 * @pages: array of page struct pointers underlying target buffer */
ll_free_user_pages(struct page ** pages,int npages,int do_dirty)216 static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
217 {
218 int i;
219
220 for (i = 0; i < npages; i++) {
221 if (do_dirty)
222 set_page_dirty_lock(pages[i]);
223 page_cache_release(pages[i]);
224 }
225 kvfree(pages);
226 }
227
ll_direct_rw_pages(const struct lu_env * env,struct cl_io * io,int rw,struct inode * inode,struct ll_dio_pages * pv)228 ssize_t ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io,
229 int rw, struct inode *inode,
230 struct ll_dio_pages *pv)
231 {
232 struct cl_page *clp;
233 struct cl_2queue *queue;
234 struct cl_object *obj = io->ci_obj;
235 int i;
236 ssize_t rc = 0;
237 loff_t file_offset = pv->ldp_start_offset;
238 long size = pv->ldp_size;
239 int page_count = pv->ldp_nr;
240 struct page **pages = pv->ldp_pages;
241 long page_size = cl_page_size(obj);
242 bool do_io;
243 int io_pages = 0;
244
245 queue = &io->ci_queue;
246 cl_2queue_init(queue);
247 for (i = 0; i < page_count; i++) {
248 if (pv->ldp_offsets)
249 file_offset = pv->ldp_offsets[i];
250
251 LASSERT(!(file_offset & (page_size - 1)));
252 clp = cl_page_find(env, obj, cl_index(obj, file_offset),
253 pv->ldp_pages[i], CPT_TRANSIENT);
254 if (IS_ERR(clp)) {
255 rc = PTR_ERR(clp);
256 break;
257 }
258
259 rc = cl_page_own(env, io, clp);
260 if (rc) {
261 LASSERT(clp->cp_state == CPS_FREEING);
262 cl_page_put(env, clp);
263 break;
264 }
265
266 do_io = true;
267
268 /* check the page type: if the page is a host page, then do
269 * write directly */
270 if (clp->cp_type == CPT_CACHEABLE) {
271 struct page *vmpage = cl_page_vmpage(env, clp);
272 struct page *src_page;
273 struct page *dst_page;
274 void *src;
275 void *dst;
276
277 src_page = (rw == WRITE) ? pages[i] : vmpage;
278 dst_page = (rw == WRITE) ? vmpage : pages[i];
279
280 src = kmap_atomic(src_page);
281 dst = kmap_atomic(dst_page);
282 memcpy(dst, src, min(page_size, size));
283 kunmap_atomic(dst);
284 kunmap_atomic(src);
285
286 /* make sure page will be added to the transfer by
287 * cl_io_submit()->...->vvp_page_prep_write(). */
288 if (rw == WRITE)
289 set_page_dirty(vmpage);
290
291 if (rw == READ) {
292 /* do not issue the page for read, since it
293 * may reread a ra page which has NOT uptodate
294 * bit set. */
295 cl_page_disown(env, io, clp);
296 do_io = false;
297 }
298 }
299
300 if (likely(do_io)) {
301 cl_2queue_add(queue, clp);
302
303 /*
304 * Set page clip to tell transfer formation engine
305 * that page has to be sent even if it is beyond KMS.
306 */
307 cl_page_clip(env, clp, 0, min(size, page_size));
308
309 ++io_pages;
310 }
311
312 /* drop the reference count for cl_page_find */
313 cl_page_put(env, clp);
314 size -= page_size;
315 file_offset += page_size;
316 }
317
318 if (rc == 0 && io_pages) {
319 rc = cl_io_submit_sync(env, io,
320 rw == READ ? CRT_READ : CRT_WRITE,
321 queue, 0);
322 }
323 if (rc == 0)
324 rc = pv->ldp_size;
325
326 cl_2queue_discard(env, io, queue);
327 cl_2queue_disown(env, io, queue);
328 cl_2queue_fini(env, queue);
329 return rc;
330 }
331 EXPORT_SYMBOL(ll_direct_rw_pages);
332
ll_direct_IO_26_seg(const struct lu_env * env,struct cl_io * io,int rw,struct inode * inode,struct address_space * mapping,size_t size,loff_t file_offset,struct page ** pages,int page_count)333 static ssize_t ll_direct_IO_26_seg(const struct lu_env *env, struct cl_io *io,
334 int rw, struct inode *inode,
335 struct address_space *mapping,
336 size_t size, loff_t file_offset,
337 struct page **pages, int page_count)
338 {
339 struct ll_dio_pages pvec = { .ldp_pages = pages,
340 .ldp_nr = page_count,
341 .ldp_size = size,
342 .ldp_offsets = NULL,
343 .ldp_start_offset = file_offset
344 };
345
346 return ll_direct_rw_pages(env, io, rw, inode, &pvec);
347 }
348
349 #ifdef KMALLOC_MAX_SIZE
350 #define MAX_MALLOC KMALLOC_MAX_SIZE
351 #else
352 #define MAX_MALLOC (128 * 1024)
353 #endif
354
355 /* This is the maximum size of a single O_DIRECT request, based on the
356 * kmalloc limit. We need to fit all of the brw_page structs, each one
357 * representing PAGE_SIZE worth of user data, into a single buffer, and
358 * then truncate this to be a full-sized RPC. For 4kB PAGE_SIZE this is
359 * up to 22MB for 128kB kmalloc and up to 682MB for 4MB kmalloc. */
360 #define MAX_DIO_SIZE ((MAX_MALLOC / sizeof(struct brw_page) * PAGE_CACHE_SIZE) & \
361 ~(DT_MAX_BRW_SIZE - 1))
ll_direct_IO_26(struct kiocb * iocb,struct iov_iter * iter,loff_t file_offset)362 static ssize_t ll_direct_IO_26(struct kiocb *iocb, struct iov_iter *iter,
363 loff_t file_offset)
364 {
365 struct lu_env *env;
366 struct cl_io *io;
367 struct file *file = iocb->ki_filp;
368 struct inode *inode = file->f_mapping->host;
369 struct ccc_object *obj = cl_inode2ccc(inode);
370 ssize_t count = iov_iter_count(iter);
371 ssize_t tot_bytes = 0, result = 0;
372 struct ll_inode_info *lli = ll_i2info(inode);
373 long size = MAX_DIO_SIZE;
374 int refcheck;
375
376 if (!lli->lli_has_smd)
377 return -EBADF;
378
379 /* Check EOF by ourselves */
380 if (iov_iter_rw(iter) == READ && file_offset >= i_size_read(inode))
381 return 0;
382
383 /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
384 if ((file_offset & ~CFS_PAGE_MASK) || (count & ~CFS_PAGE_MASK))
385 return -EINVAL;
386
387 CDEBUG(D_VFSTRACE,
388 "VFS Op:inode=%lu/%u(%p), size=%zd (max %lu), offset=%lld=%llx, pages %zd (max %lu)\n",
389 inode->i_ino, inode->i_generation, inode, count, MAX_DIO_SIZE,
390 file_offset, file_offset, count >> PAGE_CACHE_SHIFT,
391 MAX_DIO_SIZE >> PAGE_CACHE_SHIFT);
392
393 /* Check that all user buffers are aligned as well */
394 if (iov_iter_alignment(iter) & ~CFS_PAGE_MASK)
395 return -EINVAL;
396
397 env = cl_env_get(&refcheck);
398 LASSERT(!IS_ERR(env));
399 io = ccc_env_io(env)->cui_cl.cis_io;
400 LASSERT(io != NULL);
401
402 /* 0. Need locking between buffered and direct access. and race with
403 * size changing by concurrent truncates and writes.
404 * 1. Need inode mutex to operate transient pages.
405 */
406 if (iov_iter_rw(iter) == READ)
407 mutex_lock(&inode->i_mutex);
408
409 LASSERT(obj->cob_transient_pages == 0);
410 while (iov_iter_count(iter)) {
411 struct page **pages;
412 size_t offs;
413
414 count = min_t(size_t, iov_iter_count(iter), size);
415 if (iov_iter_rw(iter) == READ) {
416 if (file_offset >= i_size_read(inode))
417 break;
418 if (file_offset + count > i_size_read(inode))
419 count = i_size_read(inode) - file_offset;
420 }
421
422 result = iov_iter_get_pages_alloc(iter, &pages, count, &offs);
423 if (likely(result > 0)) {
424 int n = DIV_ROUND_UP(result + offs, PAGE_SIZE);
425
426 result = ll_direct_IO_26_seg(env, io, iov_iter_rw(iter),
427 inode, file->f_mapping,
428 result, file_offset, pages,
429 n);
430 ll_free_user_pages(pages, n, iov_iter_rw(iter) == READ);
431 }
432 if (unlikely(result <= 0)) {
433 /* If we can't allocate a large enough buffer
434 * for the request, shrink it to a smaller
435 * PAGE_SIZE multiple and try again.
436 * We should always be able to kmalloc for a
437 * page worth of page pointers = 4MB on i386. */
438 if (result == -ENOMEM &&
439 size > (PAGE_CACHE_SIZE / sizeof(*pages)) *
440 PAGE_CACHE_SIZE) {
441 size = ((((size / 2) - 1) |
442 ~CFS_PAGE_MASK) + 1) &
443 CFS_PAGE_MASK;
444 CDEBUG(D_VFSTRACE, "DIO size now %lu\n",
445 size);
446 continue;
447 }
448
449 goto out;
450 }
451 iov_iter_advance(iter, result);
452 tot_bytes += result;
453 file_offset += result;
454 }
455 out:
456 LASSERT(obj->cob_transient_pages == 0);
457 if (iov_iter_rw(iter) == READ)
458 mutex_unlock(&inode->i_mutex);
459
460 if (tot_bytes > 0) {
461 if (iov_iter_rw(iter) == WRITE) {
462 struct lov_stripe_md *lsm;
463
464 lsm = ccc_inode_lsm_get(inode);
465 LASSERT(lsm != NULL);
466 lov_stripe_lock(lsm);
467 obd_adjust_kms(ll_i2dtexp(inode), lsm, file_offset, 0);
468 lov_stripe_unlock(lsm);
469 ccc_inode_lsm_put(inode, lsm);
470 }
471 }
472
473 cl_env_put(env, &refcheck);
474 return tot_bytes ? : result;
475 }
476
ll_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)477 static int ll_write_begin(struct file *file, struct address_space *mapping,
478 loff_t pos, unsigned len, unsigned flags,
479 struct page **pagep, void **fsdata)
480 {
481 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
482 struct page *page;
483 int rc;
484 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
485
486 page = grab_cache_page_write_begin(mapping, index, flags);
487 if (!page)
488 return -ENOMEM;
489
490 *pagep = page;
491
492 rc = ll_prepare_write(file, page, from, from + len);
493 if (rc) {
494 unlock_page(page);
495 page_cache_release(page);
496 }
497 return rc;
498 }
499
ll_write_end(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct page * page,void * fsdata)500 static int ll_write_end(struct file *file, struct address_space *mapping,
501 loff_t pos, unsigned len, unsigned copied,
502 struct page *page, void *fsdata)
503 {
504 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
505 int rc;
506
507 rc = ll_commit_write(file, page, from, from + copied);
508 unlock_page(page);
509 page_cache_release(page);
510
511 return rc ?: copied;
512 }
513
514 #ifdef CONFIG_MIGRATION
ll_migratepage(struct address_space * mapping,struct page * newpage,struct page * page,enum migrate_mode mode)515 static int ll_migratepage(struct address_space *mapping,
516 struct page *newpage, struct page *page,
517 enum migrate_mode mode
518 )
519 {
520 /* Always fail page migration until we have a proper implementation */
521 return -EIO;
522 }
523 #endif
524
525 const struct address_space_operations ll_aops = {
526 .readpage = ll_readpage,
527 .direct_IO = ll_direct_IO_26,
528 .writepage = ll_writepage,
529 .writepages = ll_writepages,
530 .set_page_dirty = ll_set_page_dirty,
531 .write_begin = ll_write_begin,
532 .write_end = ll_write_end,
533 .invalidatepage = ll_invalidatepage,
534 .releasepage = (void *)ll_releasepage,
535 #ifdef CONFIG_MIGRATION
536 .migratepage = ll_migratepage,
537 #endif
538 };
539