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 (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  30  * Use is subject to license terms.
  31  *
  32  * Copyright (c) 2011, 2012, Whamcloud, Inc.
  33  */
  34 /*
  35  * This file is part of Lustre, http://www.lustre.org/
  36  * Lustre is a trademark of Sun Microsystems, Inc.
  37  *
  38  * lustre/lustre/llite/rw26.c
  39  *
  40  * Lustre Lite I/O page cache routines for the 2.5/2.6 kernel version
  41  */
  42
  43 #ifndef AUTOCONF_INCLUDED
  44 #include <linux/config.h>
  45 #endif
  46 #include <linux/kernel.h>
  47 #include <linux/mm.h>
  48 #include <linux/string.h>
  49 #include <linux/stat.h>
  50 #include <linux/errno.h>
  51 #include <linux/smp_lock.h>
  52 #include <linux/unistd.h>
  53 #include <linux/version.h>
  54 #include <asm/system.h>
  55 #include <asm/uaccess.h>
  56
  57 #include <linux/fs.h>
  58 #include <linux/buffer_head.h>
  59 #include <linux/writeback.h>
  60 #include <linux/stat.h>
  61 #include <asm/uaccess.h>
  62 #include <linux/mm.h>
  63 #include <linux/pagemap.h>
  64 #include <linux/smp_lock.h>
  65
  66 #define DEBUG_SUBSYSTEM S_LLITE
  67
  68 #include <lustre_lite.h>
  69 #include "llite_internal.h"
  70 #include <linux/lustre_compat25.h>
  71
  72 /**
  73  * Implements Linux VM address_space::invalidatepage() method. This method is
  74  * called when the page is truncate from a file, either as a result of
  75  * explicit truncate, or when inode is removed from memory (as a result of
  76  * final iput(), umount, or memory pressure induced icache shrinking).
  77  *
  78  * [0, offset] bytes of the page remain valid (this is for a case of not-page
  79  * aligned truncate). Lustre leaves partially truncated page in the cache,
  80  * relying on struct inode::i_size to limit further accesses.
  81  */
  82 static int cl_invalidatepage(struct page *vmpage, unsigned long offset)
  83 {
  84         struct inode     *inode;
  85         struct lu_env    *env;
  86         struct cl_page   *page;
  87         struct cl_object *obj;
  88
  89         int result;
  90         int refcheck;
  91
  92         LASSERT(PageLocked(vmpage));
  93         LASSERT(!PageWriteback(vmpage));
  94
  95         /*
  96          * It is safe to not check anything in invalidatepage/releasepage
  97          * below because they are run with page locked and all our io is
  98          * happening with locked page too
  99          */
 100         result = 0;
 101         if (offset == 0) {
 102                 env = cl_env_get(&refcheck);
 103                 if (!IS_ERR(env)) {
 104                         inode = vmpage->mapping->host;
 105                         obj = ll_i2info(inode)->lli_clob;
 106                         if (obj != NULL) {
 107                                 page = cl_vmpage_page(vmpage, obj);
 108                                 if (page != NULL) {
 109                                         lu_ref_add(&page->cp_reference,
 110                                                    "delete", vmpage);
 111                                         cl_page_delete(env, page);
 112                                         result = 1;
 113                                         lu_ref_del(&page->cp_reference,
 114                                                    "delete", vmpage);
 115                                         cl_page_put(env, page);
 116                                 }
 117                         } else
 118                                 LASSERT(vmpage->private == 0);
 119                         cl_env_put(env, &refcheck);
 120                 }
 121         }
 122         return result;
 123 }
 124
 125 #ifdef HAVE_INVALIDATEPAGE_RETURN_INT
 126 static int ll_invalidatepage(struct page *page, unsigned long offset)
 127 {
 128         return cl_invalidatepage(page, offset);
 129 }
 130 #else /* !HAVE_INVALIDATEPAGE_RETURN_INT */
 131 static void ll_invalidatepage(struct page *page, unsigned long offset)
 132 {
 133         cl_invalidatepage(page, offset);
 134 }
 135 #endif
 136
 137 #ifdef HAVE_RELEASEPAGE_WITH_INT
 138 #define RELEASEPAGE_ARG_TYPE int
 139 #else
 140 #define RELEASEPAGE_ARG_TYPE gfp_t
 141 #endif
 142 static int ll_releasepage(struct page *page, RELEASEPAGE_ARG_TYPE gfp_mask)
 143 {
 144         void *cookie;
 145
 146         cookie = cl_env_reenter();
 147         ll_invalidatepage(page, 0);
 148         cl_env_reexit(cookie);
 149         return 1;
 150 }
 151
 152 static int ll_set_page_dirty(struct page *vmpage)
 153 {
 154 #if 0
 155         struct cl_page    *page = vvp_vmpage_page_transient(vmpage);
 156         struct vvp_object *obj  = cl_inode2vvp(vmpage->mapping->host);
 157         struct vvp_page   *cpg;
 158
 159         /*
 160          * XXX should page method be called here?
 161          */
 162         LASSERT(&obj->co_cl == page->cp_obj);
 163         cpg = cl2vvp_page(cl_page_at(page, &vvp_device_type));
 164         /*
 165          * XXX cannot do much here, because page is possibly not locked:
 166          * sys_munmap()->...
 167          *     ->unmap_page_range()->zap_pte_range()->set_page_dirty().
 168          */
 169         vvp_write_pending(obj, cpg);
 170 #endif
 171         RETURN(__set_page_dirty_nobuffers(vmpage));
 172 }
 173
 174 #define MAX_DIRECTIO_SIZE 2*1024*1024*1024UL
 175
 176 static inline int ll_get_user_pages(int rw, unsigned long user_addr,
 177                                     size_t size, struct page ***pages,
 178                                     int *max_pages)
 179 {
 180         int result = -ENOMEM;
 181
 182         /* set an arbitrary limit to prevent arithmetic overflow */
 183         if (size > MAX_DIRECTIO_SIZE) {
 184                 *pages = NULL;
 185                 return -EFBIG;
 186         }
 187
 188         *max_pages = (user_addr + size + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
 189         *max_pages -= user_addr >> CFS_PAGE_SHIFT;
 190
 191         OBD_ALLOC_LARGE(*pages, *max_pages * sizeof(**pages));
 192         if (*pages) {
 193                 down_read(&current->mm->mmap_sem);
 194                 result = get_user_pages(current, current->mm, user_addr,
 195                                         *max_pages, (rw == READ), 0, *pages,
 196                                         NULL);
 197                 up_read(&current->mm->mmap_sem);
 198                 if (unlikely(result <= 0))
 199                         OBD_FREE_LARGE(*pages, *max_pages * sizeof(**pages));
 200         }
 201
 202         return result;
 203 }
 204
 205 /*  ll_free_user_pages - tear down page struct array
 206  *  @pages: array of page struct pointers underlying target buffer */
 207 static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
 208 {
 209         int i;
 210
 211         for (i = 0; i < npages; i++) {
 212                 if (pages[i] == NULL)
 213                         break;
 214                 if (do_dirty)
 215                         set_page_dirty_lock(pages[i]);
 216                 page_cache_release(pages[i]);
 217         }
 218
 219         OBD_FREE_LARGE(pages, npages * sizeof(*pages));
 220 }
 221
 222 ssize_t ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io,
 223                            int rw, struct inode *inode,
 224                            struct ll_dio_pages *pv)
 225 {
 226         struct cl_page    *clp;
 227         struct cl_2queue  *queue;
 228         struct cl_object  *obj = io->ci_obj;
 229         int i;
 230         ssize_t rc = 0;
 231         loff_t file_offset  = pv->ldp_start_offset;
 232         long size           = pv->ldp_size;
 233         int page_count      = pv->ldp_nr;
 234         struct page **pages = pv->ldp_pages;
 235         long page_size      = cl_page_size(obj);
 236         bool do_io;
 237         int  io_pages       = 0;
 238         ENTRY;
 239
 240         queue = &io->ci_queue;
 241         cl_2queue_init(queue);
 242         for (i = 0; i < page_count; i++) {
 243                 if (pv->ldp_offsets)
 244                     file_offset = pv->ldp_offsets[i];
 245
 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                 rc = cl_page_own(env, io, clp);
 255                 if (rc) {
 256                         LASSERT(clp->cp_state == CPS_FREEING);
 257                         cl_page_put(env, clp);
 258                         break;
 259                 }
 260
 261                 do_io = true;
 262
 263                 /* check the page type: if the page is a host page, then do
 264                  * write directly */
 265                 if (clp->cp_type == CPT_CACHEABLE) {
 266                         cfs_page_t *vmpage = cl_page_vmpage(env, clp);
 267                         cfs_page_t *src_page;
 268                         cfs_page_t *dst_page;
 269                         void       *src;
 270                         void       *dst;
 271
 272                         src_page = (rw == WRITE) ? pages[i] : vmpage;
 273                         dst_page = (rw == WRITE) ? vmpage : pages[i];
 274
 275                         src = kmap_atomic(src_page, KM_USER0);
 276                         dst = kmap_atomic(dst_page, KM_USER1);
 277                         memcpy(dst, src, min(page_size, size));
 278                         kunmap_atomic(dst, KM_USER1);
 279                         kunmap_atomic(src, KM_USER0);
 280
 281                         /* make sure page will be added to the transfer by
 282                          * cl_io_submit()->...->vvp_page_prep_write(). */
 283                         if (rw == WRITE)
 284                                 set_page_dirty(vmpage);
 285
 286                         if (rw == READ) {
 287                                 /* do not issue the page for read, since it
 288                                  * may reread a ra page which has NOT uptodate
 289                                  * bit set. */
 290                                 cl_page_disown(env, io, clp);
 291                                 do_io = false;
 292                         }
 293                 }
 294
 295                 if (likely(do_io)) {
 296                         cl_2queue_add(queue, clp);
 297
 298                         /*
 299                          * Set page clip to tell transfer formation engine
 300                          * that page has to be sent even if it is beyond KMS.
 301                          */
 302                         cl_page_clip(env, clp, 0, min(size, page_size));
 303
 304                         ++io_pages;
 305                 }
 306
 307                 /* drop the reference count for cl_page_find */
 308                 cl_page_put(env, clp);
 309                 size -= page_size;
 310                 file_offset += page_size;
 311         }
 312
 313         if (rc == 0 && io_pages) {
 314                 rc = cl_io_submit_sync(env, io,
 315                                        rw == READ ? CRT_READ : CRT_WRITE,
 316                                        queue, CRP_NORMAL, 0);
 317         }
 318         if (rc == 0)
 319                 rc = pv->ldp_size;
 320
 321         cl_2queue_discard(env, io, queue);
 322         cl_2queue_disown(env, io, queue);
 323         cl_2queue_fini(env, queue);
 324         RETURN(rc);
 325 }
 326 EXPORT_SYMBOL(ll_direct_rw_pages);
 327
 328 static ssize_t ll_direct_IO_26_seg(const struct lu_env *env, struct cl_io *io,
 329                                    int rw, struct inode *inode,
 330                                    struct address_space *mapping,
 331                                    size_t size, loff_t file_offset,
 332                                    struct page **pages, int page_count)
 333 {
 334     struct ll_dio_pages pvec = { .ldp_pages        = pages,
 335                                  .ldp_nr           = page_count,
 336                                  .ldp_size         = size,
 337                                  .ldp_offsets      = NULL,
 338                                  .ldp_start_offset = file_offset
 339                                };
 340
 341     return ll_direct_rw_pages(env, io, rw, inode, &pvec);
 342 }
 343
 344 #ifdef KMALLOC_MAX_SIZE
 345 #define MAX_MALLOC KMALLOC_MAX_SIZE
 346 #else
 347 #define MAX_MALLOC (128 * 1024)
 348 #endif
 349
 350 /* This is the maximum size of a single O_DIRECT request, based on the
 351  * kmalloc limit.  We need to fit all of the brw_page structs, each one
 352  * representing PAGE_SIZE worth of user data, into a single buffer, and
 353  * then truncate this to be a full-sized RPC.  For 4kB PAGE_SIZE this is
 354  * up to 22MB for 128kB kmalloc and up to 682MB for 4MB kmalloc. */
 355 #define MAX_DIO_SIZE ((MAX_MALLOC / sizeof(struct brw_page) * CFS_PAGE_SIZE) & \
 356                       ~(PTLRPC_MAX_BRW_SIZE - 1))
 357 static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
 358                                const struct iovec *iov, loff_t file_offset,
 359                                unsigned long nr_segs)
 360 {
 361         struct lu_env *env;
 362         struct cl_io *io;
 363         struct file *file = iocb->ki_filp;
 364         struct inode *inode = file->f_mapping->host;
 365         struct ccc_object *obj = cl_inode2ccc(inode);
 366         long count = iov_length(iov, nr_segs);
 367         long tot_bytes = 0, result = 0;
 368         struct ll_inode_info *lli = ll_i2info(inode);
 369         struct lov_stripe_md *lsm = lli->lli_smd;
 370         unsigned long seg = 0;
 371         long size = MAX_DIO_SIZE;
 372         int refcheck;
 373         ENTRY;
 374
 375         if (!lli->lli_smd || !lli->lli_smd->lsm_object_id)
 376                 RETURN(-EBADF);
 377
 378         /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
 379         if ((file_offset & ~CFS_PAGE_MASK) || (count & ~CFS_PAGE_MASK))
 380                 RETURN(-EINVAL);
 381
 382         CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p), size=%lu (max %lu), "
 383                "offset=%lld=%llx, pages %lu (max %lu)\n",
 384                inode->i_ino, inode->i_generation, inode, count, MAX_DIO_SIZE,
 385                file_offset, file_offset, count >> CFS_PAGE_SHIFT,
 386                MAX_DIO_SIZE >> CFS_PAGE_SHIFT);
 387
 388         /* Check that all user buffers are aligned as well */
 389         for (seg = 0; seg < nr_segs; seg++) {
 390                 if (((unsigned long)iov[seg].iov_base & ~CFS_PAGE_MASK) ||
 391                     (iov[seg].iov_len & ~CFS_PAGE_MASK))
 392                         RETURN(-EINVAL);
 393         }
 394
 395         env = cl_env_get(&refcheck);
 396         LASSERT(!IS_ERR(env));
 397         io = ccc_env_io(env)->cui_cl.cis_io;
 398         LASSERT(io != NULL);
 399
 400         /* 0. Need locking between buffered and direct access. and race with
 401          *    size changing by concurrent truncates and writes.
 402          * 1. Need inode sem to operate transient pages. */
 403         if (rw == READ)
 404                 LOCK_INODE_MUTEX(inode);
 405
 406         LASSERT(obj->cob_transient_pages == 0);
 407         for (seg = 0; seg < nr_segs; seg++) {
 408                 long iov_left = iov[seg].iov_len;
 409                 unsigned long user_addr = (unsigned long)iov[seg].iov_base;
 410
 411                 if (rw == READ) {
 412                         if (file_offset >= i_size_read(inode))
 413                                 break;
 414                         if (file_offset + iov_left > i_size_read(inode))
 415                                 iov_left = i_size_read(inode) - file_offset;
 416                 }
 417
 418                 while (iov_left > 0) {
 419                         struct page **pages;
 420                         int page_count, max_pages = 0;
 421                         long bytes;
 422
 423                         bytes = min(size, iov_left);
 424                         page_count = ll_get_user_pages(rw, user_addr, bytes,
 425                                                        &pages, &max_pages);
 426                         if (likely(page_count > 0)) {
 427                                 if (unlikely(page_count <  max_pages))
 428                                         bytes = page_count << CFS_PAGE_SHIFT;
 429                                 result = ll_direct_IO_26_seg(env, io, rw, inode,
 430                                                              file->f_mapping,
 431                                                              bytes, file_offset,
 432                                                              pages, page_count);
 433                                 ll_free_user_pages(pages, max_pages, rw==READ);
 434                         } else if (page_count == 0) {
 435                                 GOTO(out, result = -EFAULT);
 436                         } else {
 437                                 result = page_count;
 438                         }
 439                         if (unlikely(result <= 0)) {
 440                                 /* If we can't allocate a large enough buffer
 441                                  * for the request, shrink it to a smaller
 442                                  * PAGE_SIZE multiple and try again.
 443                                  * We should always be able to kmalloc for a
 444                                  * page worth of page pointers = 4MB on i386. */
 445                                 if (result == -ENOMEM &&
 446                                     size > (CFS_PAGE_SIZE / sizeof(*pages)) *
 447                                            CFS_PAGE_SIZE) {
 448                                         size = ((((size / 2) - 1) |
 449                                                  ~CFS_PAGE_MASK) + 1) &
 450                                                 CFS_PAGE_MASK;
 451                                         CDEBUG(D_VFSTRACE,"DIO size now %lu\n",
 452                                                size);
 453                                         continue;
 454                                 }
 455
 456                                 GOTO(out, result);
 457                         }
 458
 459                         tot_bytes += result;
 460                         file_offset += result;
 461                         iov_left -= result;
 462                         user_addr += result;
 463                 }
 464         }
 465 out:
 466         LASSERT(obj->cob_transient_pages == 0);
 467         if (rw == READ)
 468                 UNLOCK_INODE_MUTEX(inode);
 469
 470         if (tot_bytes > 0) {
 471                 if (rw == WRITE) {
 472                         lov_stripe_lock(lsm);
 473                         obd_adjust_kms(ll_i2dtexp(inode), lsm, file_offset, 0);
 474                         lov_stripe_unlock(lsm);
 475                 }
 476         }
 477
 478         cl_env_put(env, &refcheck);
 479         RETURN(tot_bytes ? : result);
 480 }
 481
 482 #if defined(HAVE_KERNEL_WRITE_BEGIN_END) || defined(MS_HAS_NEW_AOPS)
 483 static int ll_write_begin(struct file *file, struct address_space *mapping,
 484                          loff_t pos, unsigned len, unsigned flags,
 485                          struct page **pagep, void **fsdata)
 486 {
 487         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 488         struct page *page;
 489         int rc;
 490         unsigned from = pos & (PAGE_CACHE_SIZE - 1);
 491         ENTRY;
 492
 493         page = grab_cache_page_write_begin(mapping, index, flags);
 494         if (!page)
 495                 RETURN(-ENOMEM);
 496
 497         *pagep = page;
 498
 499         rc = ll_prepare_write(file, page, from, from + len);
 500         if (rc) {
 501                 unlock_page(page);
 502                 page_cache_release(page);
 503         }
 504         RETURN(rc);
 505 }
 506
 507 static int ll_write_end(struct file *file, struct address_space *mapping,
 508                         loff_t pos, unsigned len, unsigned copied,
 509                         struct page *page, void *fsdata)
 510 {
 511         unsigned from = pos & (PAGE_CACHE_SIZE - 1);
 512         int rc;
 513
 514         rc = ll_commit_write(file, page, from, from + copied);
 515         unlock_page(page);
 516         page_cache_release(page);
 517
 518         return rc ?: copied;
 519 }
 520 #endif
 521
 522 #ifdef CONFIG_MIGRATION
 523 int ll_migratepage(struct address_space *mapping,
 524                    struct page *newpage, struct page *page)
 525 {
 526         /* Always fail page migration until we have a proper implementation */
 527         return -EIO;
 528 }
 529 #endif
 530
 531 #ifndef MS_HAS_NEW_AOPS
 532 struct address_space_operations ll_aops = {
 533         .readpage       = ll_readpage,
 534 //        .readpages      = ll_readpages,
 535         .direct_IO      = ll_direct_IO_26,
 536         .writepage      = ll_writepage,
 537         .writepages     = generic_writepages,
 538         .set_page_dirty = ll_set_page_dirty,
 539         .sync_page      = NULL,
 540 #ifdef HAVE_KERNEL_WRITE_BEGIN_END
 541         .write_begin    = ll_write_begin,
 542         .write_end      = ll_write_end,
 543 #else
 544         .prepare_write  = ll_prepare_write,
 545         .commit_write   = ll_commit_write,
 546 #endif
 547         .invalidatepage = ll_invalidatepage,
 548         .releasepage    = (void *)ll_releasepage,
 549 #ifdef CONFIG_MIGRATION
 550         .migratepage    = ll_migratepage,
 551 #endif
 552         .bmap           = NULL
 553 };
 554 #else
 555 struct address_space_operations_ext ll_aops = {
 556         .orig_aops.readpage       = ll_readpage,
 557 //        .orig_aops.readpages      = ll_readpages,
 558         .orig_aops.direct_IO      = ll_direct_IO_26,
 559         .orig_aops.writepage      = ll_writepage,
 560         .orig_aops.writepages     = generic_writepages,
 561         .orig_aops.set_page_dirty = ll_set_page_dirty,
 562         .orig_aops.sync_page      = NULL,
 563         .orig_aops.prepare_write  = ll_prepare_write,
 564         .orig_aops.commit_write   = ll_commit_write,
 565         .orig_aops.invalidatepage = ll_invalidatepage,
 566         .orig_aops.releasepage    = ll_releasepage,
 567 #ifdef CONFIG_MIGRATION
 568         .orig_aops.migratepage    = ll_migratepage,
 569 #endif
 570         .orig_aops.bmap           = NULL,
 571         .write_begin    = ll_write_begin,
 572         .write_end      = ll_write_end
 573 };
 574 #endif