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[fs/lustre-release.git] / lustre / llite / rw26.c
1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2  * vim:expandtab:shiftwidth=8:tabstop=8:
3  *
4  * GPL HEADER START
5  *
6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 only,
10  * as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License version 2 for more details (a copy is included
16  * in the LICENSE file that accompanied this code).
17  *
18  * You should have received a copy of the GNU General Public License
19  * version 2 along with this program; If not, see
20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
21  *
22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23  * CA 95054 USA or visit www.sun.com if you need additional information or
24  * have any questions.
25  *
26  * GPL HEADER END
27  */
28 /*
29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
30  * Use is subject to license terms.
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 #ifndef AUTOCONF_INCLUDED
42 #include <linux/config.h>
43 #endif
44 #include <linux/kernel.h>
45 #include <linux/mm.h>
46 #include <linux/string.h>
47 #include <linux/stat.h>
48 #include <linux/errno.h>
49 #include <linux/smp_lock.h>
50 #include <linux/unistd.h>
51 #include <linux/version.h>
52 #include <asm/system.h>
53 #include <asm/uaccess.h>
54
55 #include <linux/fs.h>
56 #include <linux/buffer_head.h>
57 #include <linux/writeback.h>
58 #include <linux/stat.h>
59 #include <asm/uaccess.h>
60 #include <linux/mm.h>
61 #include <linux/pagemap.h>
62 #include <linux/smp_lock.h>
63
64 #define DEBUG_SUBSYSTEM S_LLITE
65
66 //#include <lustre_mdc.h>
67 #include <lustre_lite.h>
68 #include "llite_internal.h"
69 #include <linux/lustre_compat25.h>
70
71 /**
72  * Implements Linux VM address_space::invalidatepage() method. This method is
73  * called when the page is truncate from a file, either as a result of
74  * explicit truncate, or when inode is removed from memory (as a result of
75  * final iput(), umount, or memory pressure induced icache shrinking).
76  *
77  * [0, offset] bytes of the page remain valid (this is for a case of not-page
78  * aligned truncate). Lustre leaves partially truncated page in the cache,
79  * relying on struct inode::i_size to limit further accesses.
80  */
81 static int cl_invalidatepage(struct page *vmpage, unsigned long offset)
82 {
83         struct inode     *inode;
84         struct lu_env    *env;
85         struct cl_page   *page;
86         struct cl_object *obj;
87
88         int result;
89         int refcheck;
90
91         LASSERT(PageLocked(vmpage));
92         LASSERT(!PageWriteback(vmpage));
93
94         /*
95          * It is safe to not check anything in invalidatepage/releasepage
96          * below because they are run with page locked and all our io is
97          * happening with locked page too
98          */
99         result = 0;
100         if (offset == 0) {
101                 env = cl_env_get(&refcheck);
102                 if (!IS_ERR(env)) {
103                         inode = vmpage->mapping->host;
104                         obj = ll_i2info(inode)->lli_clob;
105                         if (obj != NULL) {
106                                 page = cl_vmpage_page(vmpage, obj);
107                                 if (page != NULL) {
108                                         lu_ref_add(&page->cp_reference,
109                                                    "delete", vmpage);
110                                         cl_page_delete(env, page);
111                                         result = 1;
112                                         lu_ref_del(&page->cp_reference,
113                                                    "delete", vmpage);
114                                         cl_page_put(env, page);
115                                 }
116                         } else
117                                 LASSERT(vmpage->private == 0);
118                         cl_env_put(env, &refcheck);
119                 }
120         }
121         return result;
122 }
123
124 #ifdef HAVE_INVALIDATEPAGE_RETURN_INT
125 static int ll_invalidatepage(struct page *page, unsigned long offset)
126 {
127         return cl_invalidatepage(page, offset);
128 }
129 #else /* !HAVE_INVALIDATEPAGE_RETURN_INT */
130 static void ll_invalidatepage(struct page *page, unsigned long offset)
131 {
132         cl_invalidatepage(page, offset);
133 }
134 #endif
135
136 #ifdef HAVE_RELEASEPAGE_WITH_INT
137 #define RELEASEPAGE_ARG_TYPE int
138 #else
139 #define RELEASEPAGE_ARG_TYPE gfp_t
140 #endif
141 static int ll_releasepage(struct page *page, RELEASEPAGE_ARG_TYPE gfp_mask)
142 {
143         void *cookie;
144
145         cookie = cl_env_reenter();
146         ll_invalidatepage(page, 0);
147         cl_env_reexit(cookie);
148         return 1;
149 }
150
151 static int ll_set_page_dirty(struct page *vmpage)
152 {
153 #if 0
154         struct cl_page    *page = vvp_vmpage_page_transient(vmpage);
155         struct vvp_object *obj  = cl_inode2vvp(vmpage->mapping->host);
156         struct vvp_page   *cpg;
157
158         /*
159          * XXX should page method be called here?
160          */
161         LASSERT(&obj->co_cl == page->cp_obj);
162         cpg = cl2vvp_page(cl_page_at(page, &vvp_device_type));
163         /*
164          * XXX cannot do much here, because page is possibly not locked:
165          * sys_munmap()->...
166          *     ->unmap_page_range()->zap_pte_range()->set_page_dirty().
167          */
168         vvp_write_pending(obj, cpg);
169 #endif
170         RETURN(__set_page_dirty_nobuffers(vmpage));
171 }
172
173 #define MAX_DIRECTIO_SIZE 2*1024*1024*1024UL
174
175 static inline int ll_get_user_pages(int rw, unsigned long user_addr,
176                                     size_t size, struct page ***pages,
177                                     int *max_pages)
178 {
179         int result = -ENOMEM;
180
181         /* set an arbitrary limit to prevent arithmetic overflow */
182         if (size > MAX_DIRECTIO_SIZE) {
183                 *pages = NULL;
184                 return -EFBIG;
185         }
186
187         *max_pages = (user_addr + size + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
188         *max_pages -= user_addr >> CFS_PAGE_SHIFT;
189
190         OBD_ALLOC_WAIT(*pages, *max_pages * sizeof(**pages));
191         if (*pages) {
192                 down_read(&current->mm->mmap_sem);
193                 result = get_user_pages(current, current->mm, user_addr,
194                                         *max_pages, (rw == READ), 0, *pages,
195                                         NULL);
196                 up_read(&current->mm->mmap_sem);
197                 if (unlikely(result <= 0))
198                         OBD_FREE(*pages, *max_pages * sizeof(**pages));
199         }
200
201         return result;
202 }
203
204 /*  ll_free_user_pages - tear down page struct array
205  *  @pages: array of page struct pointers underlying target buffer */
206 static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
207 {
208         int i;
209
210         for (i = 0; i < npages; i++) {
211                 if (pages[i] == NULL)
212                         break;
213                 if (do_dirty)
214                         set_page_dirty_lock(pages[i]);
215                 page_cache_release(pages[i]);
216         }
217
218         OBD_FREE(pages, npages * sizeof(*pages));
219 }
220
221 ssize_t ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io,
222                            int rw, struct inode *inode,
223                            struct ll_dio_pages *pv)
224 {
225         struct cl_page    *clp;
226         struct ccc_page   *clup;
227         struct cl_2queue  *queue;
228         struct cl_object  *obj = io->ci_obj;
229         struct cl_sync_io *anchor = &ccc_env_info(env)->cti_sync_io;
230         int i;
231         ssize_t rc = 0;
232         loff_t file_offset  = pv->ldp_start_offset;
233         size_t size         = pv->ldp_size;
234         int page_count      = pv->ldp_nr;
235         struct page **pages = pv->ldp_pages;
236         size_t page_size    = cl_page_size(obj);
237         ENTRY;
238
239         cl_sync_io_init(anchor, page_count);
240
241         queue = &io->ci_queue;
242         cl_2queue_init(queue);
243         for (i = 0; i < page_count; i++) {
244                 if (pv->ldp_offsets)
245                     file_offset = pv->ldp_offsets[i];
246                 LASSERT(!(file_offset & (page_size - 1)));
247                 clp = cl_page_find(env, obj, cl_index(obj, file_offset),
248                                    pv->ldp_pages[i], CPT_TRANSIENT);
249                 if (IS_ERR(clp)) {
250                         rc = PTR_ERR(clp);
251                         break;
252                 }
253
254                 /* check the page type: if the page is a host page, then do
255                  * write directly */
256                 /*
257                  * Very rare case that the host pages can be found for
258                  * directIO case, since linux kernel truncated all covered
259                  * pages before getting here. So, to make the OST happy(to
260                  * write a contiguous region), all pages are issued
261                  * here. -jay */
262                 if (clp->cp_type == CPT_CACHEABLE) {
263                         cfs_page_t *vmpage = cl_page_vmpage(env, clp);
264                         cfs_page_t *src_page;
265                         cfs_page_t *dst_page;
266                         void       *src;
267                         void       *dst;
268
269                         src_page = (rw == WRITE) ? pages[i] : vmpage;
270                         dst_page = (rw == WRITE) ? vmpage : pages[i];
271
272                         src = kmap_atomic(src_page, KM_USER0);
273                         dst = kmap_atomic(dst_page, KM_USER1);
274                         memcpy(dst, (const void *)src, min(page_size, size));
275                         kunmap_atomic(dst, KM_USER1);
276                         kunmap_atomic(src, KM_USER0);
277
278                         /* make sure page will be added to the transfer by
279                          * cl_io_submit()->...->vvp_page_prep_write(). */
280                         if (rw == WRITE)
281                                 set_page_dirty(vmpage);
282                         /*
283                          * If direct-io read finds up-to-date page in the
284                          * cache, just copy it to the user space. Page will be
285                          * filtered out by vvp_page_prep_read(). This
286                          * preserves an invariant, that page is read at most
287                          * once, see cl_page_flags::CPF_READ_COMPLETED.
288                          */
289                 }
290
291                 rc = cl_page_own(env, io, clp);
292                 if (rc) {
293                         LASSERT(clp->cp_state == CPS_FREEING);
294                         cl_page_put(env, clp);
295                         break;
296                 }
297
298                 clup = cl2ccc_page(cl_page_at(clp, &vvp_device_type));
299                 clup->cpg_sync_io = anchor;
300                 cl_2queue_add(queue, clp);
301
302                 /* drop the reference count for cl_page_find, so that the page
303                  * will be freed in cl_2queue_fini. */
304                 cl_page_put(env, clp);
305                 /*
306                  * Set page clip to tell transfer formation engine that page
307                  * has to be sent even if it is beyond KMS.
308                  */
309                 cl_page_clip(env, clp, 0, min(size, page_size));
310                 size -= page_size;
311                 file_offset += page_size;
312         }
313
314         if (rc == 0) {
315                 rc = cl_io_submit_rw(env, io, rw == READ ? CRT_READ : CRT_WRITE,
316                                      queue, CRP_NORMAL);
317                 if (rc == 0) {
318                         /*
319                          * If some pages weren't sent for any reason (e.g.,
320                          * direct-io read found up-to-date pages in the
321                          * cache), count them as completed to avoid infinite
322                          * wait.
323                          */
324                         cl_page_list_for_each(clp, &queue->c2_qin)
325                                 cl_sync_io_note(anchor, +1);
326                         /* wait for the IO to be finished. */
327                         rc = cl_sync_io_wait(env, io, &queue->c2_qout,
328                                              anchor) ?: pv->ldp_size;
329                 }
330         }
331
332         cl_2queue_discard(env, io, queue);
333         cl_2queue_disown(env, io, queue);
334         cl_2queue_fini(env, queue);
335         RETURN(rc);
336 }
337 EXPORT_SYMBOL(ll_direct_rw_pages);
338
339 static ssize_t ll_direct_IO_26_seg(const struct lu_env *env, struct cl_io *io,
340                                    int rw, struct inode *inode,
341                                    struct address_space *mapping,
342                                    size_t size, loff_t file_offset,
343                                    struct page **pages, int page_count)
344 {
345     struct ll_dio_pages pvec = { .ldp_pages        = pages,
346                                  .ldp_nr           = page_count,
347                                  .ldp_size         = size,
348                                  .ldp_offsets      = NULL,
349                                  .ldp_start_offset = file_offset
350                                };
351
352     return ll_direct_rw_pages(env, io, rw, inode, &pvec);
353 }
354
355 /* This is the maximum size of a single O_DIRECT request, based on a 128kB
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.  This is 22MB for 4kB pages. */
359 #define MAX_DIO_SIZE ((128 * 1024 / sizeof(struct brw_page) * CFS_PAGE_SIZE) & \
360                       ~(PTLRPC_MAX_BRW_SIZE - 1))
361 static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
362                                const struct iovec *iov, loff_t file_offset,
363                                unsigned long nr_segs)
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_length(iov, nr_segs);
371         ssize_t tot_bytes = 0, result = 0;
372         struct ll_inode_info *lli = ll_i2info(inode);
373         struct lov_stripe_md *lsm = lli->lli_smd;
374         unsigned long seg = 0;
375         size_t size = MAX_DIO_SIZE;
376         int refcheck;
377         ENTRY;
378
379         if (!lli->lli_smd || !lli->lli_smd->lsm_object_id)
380                 RETURN(-EBADF);
381
382         /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
383         if ((file_offset & ~CFS_PAGE_MASK) || (count & ~CFS_PAGE_MASK))
384                 RETURN(-EINVAL);
385
386         CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p), size="LPSZ" (max %lu), "
387                "offset=%lld=%llx, pages "LPSZ" (max %lu)\n",
388                inode->i_ino, inode->i_generation, inode, count, MAX_DIO_SIZE,
389                file_offset, file_offset, count >> CFS_PAGE_SHIFT,
390                MAX_DIO_SIZE >> CFS_PAGE_SHIFT);
391
392         /* Check that all user buffers are aligned as well */
393         for (seg = 0; seg < nr_segs; seg++) {
394                 if (((unsigned long)iov[seg].iov_base & ~CFS_PAGE_MASK) ||
395                     (iov[seg].iov_len & ~CFS_PAGE_MASK))
396                         RETURN(-EINVAL);
397         }
398
399         env = cl_env_get(&refcheck);
400         LASSERT(!IS_ERR(env));
401         io = ccc_env_io(env)->cui_cl.cis_io;
402         LASSERT(io != NULL);
403
404         /* 0. Need locking between buffered and direct access. and race with
405          *size changing by concurrent truncates and writes.
406          * 1. Need inode sem to operate transient pages. */
407         if (rw == READ)
408                 LOCK_INODE_MUTEX(inode);
409
410         LASSERT(obj->cob_transient_pages == 0);
411         for (seg = 0; seg < nr_segs; seg++) {
412                 size_t iov_left = iov[seg].iov_len;
413                 unsigned long user_addr = (unsigned long)iov[seg].iov_base;
414
415                 if (rw == READ) {
416                         if (file_offset >= inode->i_size)
417                                 break;
418                         if (file_offset + iov_left > inode->i_size)
419                                 iov_left = inode->i_size - file_offset;
420                 }
421
422                 while (iov_left > 0) {
423                         struct page **pages;
424                         int page_count, max_pages = 0;
425                         size_t bytes;
426
427                         bytes = min(size,iov_left);
428                         page_count = ll_get_user_pages(rw, user_addr,
429                                                        bytes,
430                                                        &pages, &max_pages);
431                         if (likely(page_count > 0)) {
432                                 if (unlikely(page_count <  max_pages))
433                                         bytes = page_count << CFS_PAGE_SHIFT;
434                                 result = ll_direct_IO_26_seg(env, io, rw, inode,
435                                                              file->f_mapping,
436                                                              bytes,
437                                                              file_offset, pages,
438                                                              page_count);
439                                 ll_free_user_pages(pages, max_pages, rw==READ);
440                         } else if (page_count == 0) {
441                                 GOTO(out, result = -EFAULT);
442                         } else {
443                                 result = page_count;
444                         }
445                         if (unlikely(result <= 0)) {
446                                 /* If we can't allocate a large enough buffer
447                                  * for the request, shrink it to a smaller
448                                  * PAGE_SIZE multiple and try again.
449                                  * We should always be able to kmalloc for a
450                                  * page worth of page pointers = 4MB on i386. */
451                                 if (result == -ENOMEM &&
452                                     size > (CFS_PAGE_SIZE / sizeof(*pages)) *
453                                            CFS_PAGE_SIZE) {
454                                         size = ((((size / 2) - 1) |
455                                                  ~CFS_PAGE_MASK) + 1) &
456                                                 CFS_PAGE_MASK;
457                                         CDEBUG(D_VFSTRACE, "DIO size now %u\n",
458                                                (int)size);
459                                         continue;
460                                 }
461
462                                 GOTO(out, result);
463                         }
464
465                         tot_bytes += result;
466                         file_offset += result;
467                         iov_left -= result;
468                         user_addr += result;
469                 }
470         }
471 out:
472         LASSERT(obj->cob_transient_pages == 0);
473         if (rw == READ)
474                 UNLOCK_INODE_MUTEX(inode);
475
476         if (tot_bytes > 0) {
477                 if (rw == WRITE) {
478                         lov_stripe_lock(lsm);
479                         obd_adjust_kms(ll_i2dtexp(inode), lsm, file_offset, 0);
480                         lov_stripe_unlock(lsm);
481                 }
482         }
483
484         cl_env_put(env, &refcheck);
485         RETURN(tot_bytes ? : result);
486 }
487
488 struct address_space_operations ll_aops = {
489         .readpage       = ll_readpage,
490 //        .readpages      = ll_readpages,
491         .direct_IO      = ll_direct_IO_26,
492         .writepage      = ll_writepage,
493         .writepages     = generic_writepages,
494         .set_page_dirty = ll_set_page_dirty,
495         .sync_page      = NULL,
496         .prepare_write  = ll_prepare_write,
497         .commit_write   = ll_commit_write,
498         .invalidatepage = ll_invalidatepage,
499         .releasepage    = (void *)ll_releasepage,
500         .bmap           = NULL
501 };