lustre/obdfilter/filter_io_26.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  linux/fs/obdfilter/filter_io.c
   5  *
   6  *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
   7  *   Author: Peter Braam <braam@clusterfs.com>
   8  *   Author: Andreas Dilger <adilger@clusterfs.com>
   9  *   Author: Phil Schwan <phil@clusterfs.com>
  10  *
  11  *   This file is part of Lustre, http://www.lustre.org.
  12  *
  13  *   Lustre is free software; you can redistribute it and/or
  14  *   modify it under the terms of version 2 of the GNU General Public
  15  *   License as published by the Free Software Foundation.
  16  *
  17  *   Lustre is distributed in the hope that it will be useful,
  18  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *   GNU General Public License for more details.
  21  *
  22  *   You should have received a copy of the GNU General Public License
  23  *   along with Lustre; if not, write to the Free Software
  24  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26
  27 #include <linux/config.h>
  28 #include <linux/module.h>
  29 #include <linux/pagemap.h> // XXX kill me soon
  30 #include <linux/version.h>
  31 #include <linux/buffer_head.h>
  32
  33 #define DEBUG_SUBSYSTEM S_FILTER
  34
  35 #include <linux/obd_class.h>
  36 #include <linux/lustre_fsfilt.h>
  37 #include "filter_internal.h"
  38
  39 #warning "implement writeback mode -bzzz"
  40
  41 /* 512byte block min */
  42 #define MAX_BLOCKS_PER_PAGE (PAGE_SIZE / 512)
  43 struct dio_request {
  44         atomic_t          dr_numreqs;  /* number of reqs being processed */
  45         struct bio       *dr_bios;     /* list of completed bios */
  46         wait_queue_head_t dr_wait;
  47         int               dr_max_pages;
  48         int               dr_npages;
  49         int               dr_error;
  50         struct page     **dr_pages;
  51         unsigned long    *dr_blocks;
  52         spinlock_t        dr_lock;
  53 };
  54
  55 static int dio_complete_routine(struct bio *bio, unsigned int done, int error)
  56 {
  57         struct dio_request *dreq = bio->bi_private;
  58         unsigned long flags;
  59
  60         spin_lock_irqsave(&dreq->dr_lock, flags);
  61         bio->bi_private = dreq->dr_bios;
  62         dreq->dr_bios = bio;
  63         if (dreq->dr_error == 0)
  64                 dreq->dr_error = error;
  65         spin_unlock_irqrestore(&dreq->dr_lock, flags);
  66
  67         if (atomic_dec_and_test(&dreq->dr_numreqs))
  68                 wake_up(&dreq->dr_wait);
  69
  70         return 0;
  71 }
  72
  73 static int can_be_merged(struct bio *bio, sector_t sector)
  74 {
  75         unsigned int size;
  76
  77         if (!bio)
  78                 return 0;
  79
  80         size = bio->bi_size >> 9;
  81         return bio->bi_sector + size == sector ? 1 : 0;
  82 }
  83
  84 int filter_alloc_iobuf(int rw, int num_pages, void **ret)
  85 {
  86         struct dio_request *dreq;
  87
  88         LASSERTF(rw == OBD_BRW_WRITE || rw == OBD_BRW_READ, "%x\n", rw);
  89
  90         OBD_ALLOC(dreq, sizeof(*dreq));
  91         if (dreq == NULL)
  92                 goto failed_0;
  93
  94         OBD_ALLOC(dreq->dr_pages, num_pages * sizeof(*dreq->dr_pages));
  95         if (dreq->dr_pages == NULL)
  96                 goto failed_1;
  97
  98         OBD_ALLOC(dreq->dr_blocks,
  99                   MAX_BLOCKS_PER_PAGE * num_pages * sizeof(*dreq->dr_blocks));
 100         if (dreq->dr_blocks == NULL)
 101                 goto failed_2;
 102
 103         dreq->dr_bios = NULL;
 104         init_waitqueue_head(&dreq->dr_wait);
 105         atomic_set(&dreq->dr_numreqs, 0);
 106         spin_lock_init(&dreq->dr_lock);
 107         dreq->dr_max_pages = num_pages;
 108         dreq->dr_npages = 0;
 109
 110         *ret = dreq;
 111         RETURN(0);
 112
 113  failed_2:
 114         OBD_FREE(dreq->dr_pages,
 115                  num_pages * sizeof(*dreq->dr_pages));
 116  failed_1:
 117         OBD_FREE(dreq, sizeof(*dreq));
 118  failed_0:
 119         RETURN(-ENOMEM);
 120 }
 121
 122 void filter_free_iobuf(void *iobuf)
 123 {
 124         struct dio_request *dreq = iobuf;
 125         int                 num_pages = dreq->dr_max_pages;
 126
 127         /* free all bios */
 128         while (dreq->dr_bios) {
 129                 struct bio *bio = dreq->dr_bios;
 130                 dreq->dr_bios = bio->bi_private;
 131                 bio_put(bio);
 132         }
 133
 134         OBD_FREE(dreq->dr_blocks,
 135                  MAX_BLOCKS_PER_PAGE * num_pages * sizeof(*dreq->dr_blocks));
 136         OBD_FREE(dreq->dr_pages,
 137                  num_pages * sizeof(*dreq->dr_pages));
 138         OBD_FREE(dreq, sizeof(*dreq));
 139 }
 140
 141 int filter_iobuf_add_page(struct obd_device *obd, void *iobuf,
 142                           struct inode *inode, struct page *page)
 143 {
 144         struct dio_request *dreq = iobuf;
 145
 146         LASSERT (dreq->dr_npages < dreq->dr_max_pages);
 147         dreq->dr_pages[dreq->dr_npages++] = page;
 148
 149         return 0;
 150 }
 151
 152 int filter_do_bio(struct obd_device *obd, struct inode *inode,
 153                   struct dio_request *dreq, int rw)
 154 {
 155         int            blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
 156         struct page  **pages = dreq->dr_pages;
 157         int            npages = dreq->dr_npages;
 158         unsigned long *blocks = dreq->dr_blocks;
 159         int            total_blocks = npages * blocks_per_page;
 160         int            sector_bits = inode->i_sb->s_blocksize_bits - 9;
 161         unsigned int   blocksize = inode->i_sb->s_blocksize;
 162         struct bio    *bio = NULL;
 163         struct page   *page;
 164         unsigned int   page_offset;
 165         sector_t       sector;
 166         int            nblocks;
 167         int            block_idx;
 168         int            page_idx;
 169         int            i;
 170         int            rc = 0;
 171         ENTRY;
 172
 173         LASSERT(dreq->dr_npages == npages);
 174         LASSERT(total_blocks <= OBDFILTER_CREATED_SCRATCHPAD_ENTRIES);
 175
 176         for (page_idx = 0, block_idx = 0;
 177              page_idx < npages;
 178              page_idx++, block_idx += blocks_per_page) {
 179
 180                 page = pages[page_idx];
 181                 LASSERT (block_idx + blocks_per_page <= total_blocks);
 182
 183                 for (i = 0, page_offset = 0;
 184                      i < blocks_per_page;
 185                      i += nblocks, page_offset += blocksize * nblocks) {
 186
 187                         nblocks = 1;
 188
 189                         if (blocks[block_idx + i] == 0) {  /* hole */
 190                                 LASSERT(rw == OBD_BRW_READ);
 191                                 memset(kmap(page) + page_offset, 0, blocksize);
 192                                 kunmap(page);
 193                                 continue;
 194                         }
 195
 196                         sector = blocks[block_idx + i] << sector_bits;
 197
 198                         /* Additional contiguous file blocks? */
 199                         while (i + nblocks < blocks_per_page &&
 200                                (sector + nblocks*(blocksize>>9)) ==
 201                                (blocks[block_idx + i + nblocks] << sector_bits))
 202                                 nblocks++;
 203
 204                         if (bio != NULL &&
 205                             can_be_merged(bio, sector) &&
 206                             bio_add_page(bio, page,
 207                                          blocksize * nblocks, page_offset) != 0)
 208                                 continue;       /* added this frag OK */
 209
 210                         if (bio != NULL) {
 211                                 request_queue_t *q = bdev_get_queue(bio->bi_bdev);
 212
 213                                 /* Dang! I have to fragment this I/O */
 214                                 CDEBUG(D_INODE, "bio++ sz %d vcnt %d(%d) "
 215                                        "sectors %d(%d) psg %d(%d) hsg %d(%d)\n",
 216                                        bio->bi_size,
 217                                        bio->bi_vcnt, bio->bi_max_vecs,
 218                                        bio->bi_size >> 9, q->max_sectors,
 219                                        bio_phys_segments(q, bio),
 220                                        q->max_phys_segments,
 221                                        bio_hw_segments(q, bio),
 222                                        q->max_hw_segments);
 223
 224                                 atomic_inc(&dreq->dr_numreqs);
 225                                 rc = fsfilt_send_bio(rw, obd, inode, bio);
 226                                 if (rc < 0) {
 227                                         CERROR("Can't send bio: %d\n", rc);
 228                                         /* OK do dec; we do the waiting */
 229                                         atomic_dec(&dreq->dr_numreqs);
 230                                         goto out;
 231                                 }
 232                                 rc = 0;
 233
 234                                 bio = NULL;
 235                         }
 236
 237                         /* allocate new bio */
 238                         bio = bio_alloc(GFP_NOIO,
 239                                         (npages - page_idx) * blocks_per_page);
 240                         if (bio == NULL) {
 241                                 CERROR ("Can't allocate bio\n");
 242                                 rc = -ENOMEM;
 243                                 goto out;
 244                         }
 245
 246                         bio->bi_bdev = inode->i_sb->s_bdev;
 247                         bio->bi_sector = sector;
 248                         bio->bi_end_io = dio_complete_routine;
 249                         bio->bi_private = dreq;
 250
 251                         rc = bio_add_page(bio, page,
 252                                           blocksize * nblocks, page_offset);
 253                         LASSERT (rc != 0);
 254                 }
 255         }
 256
 257         if (bio != NULL) {
 258                 atomic_inc(&dreq->dr_numreqs);
 259                 rc = fsfilt_send_bio(rw, obd, inode, bio);
 260                 if (rc >= 0) {
 261                         rc = 0;
 262                 } else {
 263                         CERROR("Can't send bio: %d\n", rc);
 264                         /* OK do dec; we do the waiting */
 265                         atomic_dec(&dreq->dr_numreqs);
 266                 }
 267         }
 268
 269  out:
 270         wait_event(dreq->dr_wait, atomic_read(&dreq->dr_numreqs) == 0);
 271
 272         if (rc == 0)
 273                 rc = dreq->dr_error;
 274         RETURN(rc);
 275 }
 276
 277 static void filter_clear_page_cache(struct inode *inode, struct bio *iobuf)
 278 {
 279 #if 0
 280         struct page *page;
 281         int i;
 282
 283         for (i = 0; i < iobuf->nr_pages ; i++) {
 284                 page = find_lock_page(inode->i_mapping,
 285                                       iobuf->maplist[i]->index);
 286                 if (page == NULL)
 287                         continue;
 288                 if (page->mapping != NULL) {
 289                         block_invalidatepage(page, 0);
 290                         truncate_complete_page(page);
 291                 }
 292                 unlock_page(page);
 293                 page_cache_release(page);
 294         }
 295 #endif
 296 }
 297
 298 /* Must be called with i_sem taken for writes; this will drop it */
 299 int filter_direct_io(int rw, struct dentry *dchild, void *iobuf,
 300                      struct obd_export *exp, struct iattr *attr,
 301                      struct obd_trans_info *oti, void **wait_handle)
 302 {
 303         struct obd_device *obd = exp->exp_obd;
 304         struct dio_request *dreq = iobuf;
 305         struct inode *inode = dchild->d_inode;
 306         int rc;
 307         int rc2;
 308         ENTRY;
 309
 310         LASSERTF(rw == OBD_BRW_WRITE || rw == OBD_BRW_READ, "%x\n", rw);
 311         LASSERTF(dreq->dr_npages <= dreq->dr_max_pages, "%d,%d\n",
 312                  dreq->dr_npages, dreq->dr_max_pages);
 313
 314         /* XXX FIXME these assertions should be handled properly here or
 315          * checked elsewhere */
 316         LASSERT(dreq->dr_npages <= OBDFILTER_CREATED_SCRATCHPAD_ENTRIES);
 317         if (dreq->dr_npages == 0)
 318                 RETURN(0);
 319
 320         rc = fsfilt_map_inode_pages(obd, inode,
 321                                     dreq->dr_pages, dreq->dr_npages,
 322                                     dreq->dr_blocks,
 323                                     obdfilter_created_scratchpad,
 324                                     rw == OBD_BRW_WRITE, NULL);
 325
 326         if (rw == OBD_BRW_WRITE) {
 327                 if (rc == 0) {
 328 #if 0
 329                         filter_tally_write(&obd->u.filter,
 330                                            dreq->dr_pages,
 331                                            dreq->dr_page_idx,
 332                                            dreq->dr_blocks,
 333                                            blocks_per_page);
 334 #endif
 335                         if (attr->ia_size > inode->i_size)
 336                                 attr->ia_valid |= ATTR_SIZE;
 337                         rc = fsfilt_setattr(obd, dchild,
 338                                             oti->oti_handle, attr, 0);
 339                 }
 340
 341                 up(&inode->i_sem);
 342
 343                 rc2 = filter_finish_transno(exp, oti, 0);
 344                 if (rc2 != 0)
 345                         CERROR("can't close transaction: %d\n", rc);
 346
 347                 if (rc == 0)
 348                         rc = rc2;
 349                 if (rc != 0)
 350                         RETURN(rc);
 351
 352         }
 353
 354         /* This is nearly osync_inode, without the waiting
 355         rc = generic_osync_inode(inode, inode->i_mapping,
 356                                  OSYNC_DATA|OSYNC_METADATA); */
 357         rc = filemap_fdatawrite(inode->i_mapping);
 358         rc2 = sync_mapping_buffers(inode->i_mapping);
 359         if (rc == 0)
 360                 rc = rc2;
 361         rc2 = filemap_fdatawait(inode->i_mapping);
 362         if (rc == 0)
 363                 rc = rc2;
 364
 365         if (rc != 0)
 366                 RETURN(rc);
 367
 368         /* be careful to call this after fsync_inode_data_buffers has waited
 369          * for IO to complete before we evict it from the cache */
 370         filter_clear_page_cache(inode, iobuf);
 371
 372         RETURN(filter_do_bio(obd, inode, dreq, rw));
 373 }
 374
 375 /* See if there are unallocated parts in given file region */
 376 static int filter_range_is_mapped(struct inode *inode, obd_size offset, int len)
 377 {
 378         sector_t (*fs_bmap)(struct address_space *, sector_t) =
 379                 inode->i_mapping->a_ops->bmap;
 380         int j;
 381
 382         /* We can't know if we are overwriting or not */
 383         if (fs_bmap == NULL)
 384                 return 0;
 385
 386         offset >>= inode->i_blkbits;
 387         len >>= inode->i_blkbits;
 388
 389         for (j = 0; j <= len; j++)
 390                 if (fs_bmap(inode->i_mapping, offset + j) == 0)
 391                         return 0;
 392
 393         return 1;
 394 }
 395
 396 int filter_commitrw_write(struct obd_export *exp, struct obdo *oa,
 397                           int objcount, struct obd_ioobj *obj, int niocount,
 398                           struct niobuf_local *res, struct obd_trans_info *oti,
 399                           int rc)
 400 {
 401         struct niobuf_local *lnb;
 402         struct dio_request *dreq = NULL;
 403         struct obd_run_ctxt saved;
 404         struct fsfilt_objinfo fso;
 405         struct iattr iattr = { 0 };
 406         struct inode *inode = NULL;
 407         unsigned long now = jiffies;
 408         int i, err, cleanup_phase = 0;
 409         struct obd_device *obd = exp->exp_obd;
 410         int   total_size = 0;
 411         ENTRY;
 412
 413         LASSERT(oti != NULL);
 414         LASSERT(objcount == 1);
 415         LASSERT(current->journal_info == NULL);
 416
 417         if (rc != 0)
 418                 GOTO(cleanup, rc);
 419
 420         rc = filter_alloc_iobuf(OBD_BRW_WRITE, obj->ioo_bufcnt, (void **)&dreq);
 421         if (rc)
 422                 GOTO(cleanup, rc);
 423         cleanup_phase = 1;
 424
 425         fso.fso_dentry = res->dentry;
 426         fso.fso_bufcnt = obj->ioo_bufcnt;
 427         inode = res->dentry->d_inode;
 428
 429         for (i = 0, lnb = res; i < obj->ioo_bufcnt; i++, lnb++) {
 430                 loff_t this_size;
 431
 432                 /* If overwriting an existing block, we don't need a grant */
 433                 if (!(lnb->flags & OBD_BRW_GRANTED) && lnb->rc == -ENOSPC &&
 434                     filter_range_is_mapped(inode, lnb->offset, lnb->len))
 435                         lnb->rc = 0;
 436
 437                 if (lnb->rc) { /* ENOSPC, network RPC error, etc. */
 438                         CDEBUG(D_INODE, "Skipping [%d] == %d\n", i, lnb->rc);
 439                         continue;
 440                 }
 441
 442                 err = filter_iobuf_add_page(obd, dreq, inode, lnb->page);
 443                 LASSERT (err == 0);
 444
 445                 total_size += lnb->len;
 446
 447                 /* we expect these pages to be in offset order, but we'll
 448                  * be forgiving */
 449                 this_size = lnb->offset + lnb->len;
 450                 if (this_size > iattr.ia_size)
 451                         iattr.ia_size = this_size;
 452         }
 453 #if 0
 454         /* I use this when I'm checking our lovely 1M I/Os reach the disk -eeb */
 455         if (total_size != (1<<20))
 456                 CWARN("total size %d (%d pages)\n",
 457                       total_size, total_size/PAGE_SIZE);
 458 #endif
 459         push_ctxt(&saved, &obd->obd_ctxt, NULL);
 460         cleanup_phase = 2;
 461
 462         down(&inode->i_sem);
 463         oti->oti_handle = fsfilt_brw_start(obd, objcount, &fso, niocount, res,
 464                                            oti);
 465         if (IS_ERR(oti->oti_handle)) {
 466                 up(&inode->i_sem);
 467                 rc = PTR_ERR(oti->oti_handle);
 468                 CDEBUG(rc == -ENOSPC ? D_INODE : D_ERROR,
 469                        "error starting transaction: rc = %d\n", rc);
 470                 oti->oti_handle = NULL;
 471                 GOTO(cleanup, rc);
 472         }
 473         /* have to call fsfilt_commit() from this point on */
 474
 475         fsfilt_check_slow(now, obd_timeout, "brw_start");
 476
 477         iattr_from_obdo(&iattr,oa,OBD_MD_FLATIME|OBD_MD_FLMTIME|OBD_MD_FLCTIME);
 478         /* filter_direct_io drops i_sem */
 479         rc = filter_direct_io(OBD_BRW_WRITE, res->dentry, dreq, exp, &iattr,
 480                               oti, NULL);
 481         if (rc == 0)
 482                 obdo_from_inode(oa, inode, FILTER_VALID_FLAGS);
 483
 484         fsfilt_check_slow(now, obd_timeout, "direct_io");
 485
 486         err = fsfilt_commit(obd, inode, oti->oti_handle, obd_sync_filter);
 487         if (err)
 488                 rc = err;
 489
 490         if (obd_sync_filter && !err)
 491                 LASSERT(oti->oti_transno <= obd->obd_last_committed);
 492
 493         fsfilt_check_slow(now, obd_timeout, "commitrw commit");
 494
 495 cleanup:
 496         filter_grant_commit(exp, niocount, res);
 497
 498         switch (cleanup_phase) {
 499         case 2:
 500                 pop_ctxt(&saved, &obd->obd_ctxt, NULL);
 501                 LASSERT(current->journal_info == NULL);
 502         case 1:
 503                 filter_free_iobuf(dreq);
 504         case 0:
 505                 filter_free_dio_pages(objcount, obj, niocount, res);
 506                 f_dput(res->dentry);
 507         }
 508
 509         RETURN(rc);
 510 }