linux/fs/ocfs2/aops.c
<<
>>
Prefs
   1/* -*- mode: c; c-basic-offset: 8; -*-
   2 * vim: noexpandtab sw=8 ts=8 sts=0:
   3 *
   4 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public
   8 * License as published by the Free Software Foundation; either
   9 * version 2 of the License, or (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public
  17 * License along with this program; if not, write to the
  18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 * Boston, MA 021110-1307, USA.
  20 */
  21
  22#include <linux/fs.h>
  23#include <linux/slab.h>
  24#include <linux/highmem.h>
  25#include <linux/pagemap.h>
  26#include <asm/byteorder.h>
  27#include <linux/swap.h>
  28#include <linux/pipe_fs_i.h>
  29#include <linux/mpage.h>
  30#include <linux/quotaops.h>
  31
  32#include <cluster/masklog.h>
  33
  34#include "ocfs2.h"
  35
  36#include "alloc.h"
  37#include "aops.h"
  38#include "dlmglue.h"
  39#include "extent_map.h"
  40#include "file.h"
  41#include "inode.h"
  42#include "journal.h"
  43#include "suballoc.h"
  44#include "super.h"
  45#include "symlink.h"
  46#include "refcounttree.h"
  47#include "ocfs2_trace.h"
  48
  49#include "buffer_head_io.h"
  50
  51static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
  52                                   struct buffer_head *bh_result, int create)
  53{
  54        int err = -EIO;
  55        int status;
  56        struct ocfs2_dinode *fe = NULL;
  57        struct buffer_head *bh = NULL;
  58        struct buffer_head *buffer_cache_bh = NULL;
  59        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  60        void *kaddr;
  61
  62        trace_ocfs2_symlink_get_block(
  63                        (unsigned long long)OCFS2_I(inode)->ip_blkno,
  64                        (unsigned long long)iblock, bh_result, create);
  65
  66        BUG_ON(ocfs2_inode_is_fast_symlink(inode));
  67
  68        if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
  69                mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
  70                     (unsigned long long)iblock);
  71                goto bail;
  72        }
  73
  74        status = ocfs2_read_inode_block(inode, &bh);
  75        if (status < 0) {
  76                mlog_errno(status);
  77                goto bail;
  78        }
  79        fe = (struct ocfs2_dinode *) bh->b_data;
  80
  81        if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
  82                                                    le32_to_cpu(fe->i_clusters))) {
  83                mlog(ML_ERROR, "block offset is outside the allocated size: "
  84                     "%llu\n", (unsigned long long)iblock);
  85                goto bail;
  86        }
  87
  88        /* We don't use the page cache to create symlink data, so if
  89         * need be, copy it over from the buffer cache. */
  90        if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
  91                u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
  92                            iblock;
  93                buffer_cache_bh = sb_getblk(osb->sb, blkno);
  94                if (!buffer_cache_bh) {
  95                        mlog(ML_ERROR, "couldn't getblock for symlink!\n");
  96                        goto bail;
  97                }
  98
  99                /* we haven't locked out transactions, so a commit
 100                 * could've happened. Since we've got a reference on
 101                 * the bh, even if it commits while we're doing the
 102                 * copy, the data is still good. */
 103                if (buffer_jbd(buffer_cache_bh)
 104                    && ocfs2_inode_is_new(inode)) {
 105                        kaddr = kmap_atomic(bh_result->b_page);
 106                        if (!kaddr) {
 107                                mlog(ML_ERROR, "couldn't kmap!\n");
 108                                goto bail;
 109                        }
 110                        memcpy(kaddr + (bh_result->b_size * iblock),
 111                               buffer_cache_bh->b_data,
 112                               bh_result->b_size);
 113                        kunmap_atomic(kaddr);
 114                        set_buffer_uptodate(bh_result);
 115                }
 116                brelse(buffer_cache_bh);
 117        }
 118
 119        map_bh(bh_result, inode->i_sb,
 120               le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
 121
 122        err = 0;
 123
 124bail:
 125        brelse(bh);
 126
 127        return err;
 128}
 129
 130int ocfs2_get_block(struct inode *inode, sector_t iblock,
 131                    struct buffer_head *bh_result, int create)
 132{
 133        int err = 0;
 134        unsigned int ext_flags;
 135        u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
 136        u64 p_blkno, count, past_eof;
 137        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 138
 139        trace_ocfs2_get_block((unsigned long long)OCFS2_I(inode)->ip_blkno,
 140                              (unsigned long long)iblock, bh_result, create);
 141
 142        if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
 143                mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
 144                     inode, inode->i_ino);
 145
 146        if (S_ISLNK(inode->i_mode)) {
 147                /* this always does I/O for some reason. */
 148                err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
 149                goto bail;
 150        }
 151
 152        err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
 153                                          &ext_flags);
 154        if (err) {
 155                mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
 156                     "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
 157                     (unsigned long long)p_blkno);
 158                goto bail;
 159        }
 160
 161        if (max_blocks < count)
 162                count = max_blocks;
 163
 164        /*
 165         * ocfs2 never allocates in this function - the only time we
 166         * need to use BH_New is when we're extending i_size on a file
 167         * system which doesn't support holes, in which case BH_New
 168         * allows __block_write_begin() to zero.
 169         *
 170         * If we see this on a sparse file system, then a truncate has
 171         * raced us and removed the cluster. In this case, we clear
 172         * the buffers dirty and uptodate bits and let the buffer code
 173         * ignore it as a hole.
 174         */
 175        if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
 176                clear_buffer_dirty(bh_result);
 177                clear_buffer_uptodate(bh_result);
 178                goto bail;
 179        }
 180
 181        /* Treat the unwritten extent as a hole for zeroing purposes. */
 182        if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 183                map_bh(bh_result, inode->i_sb, p_blkno);
 184
 185        bh_result->b_size = count << inode->i_blkbits;
 186
 187        if (!ocfs2_sparse_alloc(osb)) {
 188                if (p_blkno == 0) {
 189                        err = -EIO;
 190                        mlog(ML_ERROR,
 191                             "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
 192                             (unsigned long long)iblock,
 193                             (unsigned long long)p_blkno,
 194                             (unsigned long long)OCFS2_I(inode)->ip_blkno);
 195                        mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
 196                        dump_stack();
 197                        goto bail;
 198                }
 199        }
 200
 201        past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
 202
 203        trace_ocfs2_get_block_end((unsigned long long)OCFS2_I(inode)->ip_blkno,
 204                                  (unsigned long long)past_eof);
 205        if (create && (iblock >= past_eof))
 206                set_buffer_new(bh_result);
 207
 208bail:
 209        if (err < 0)
 210                err = -EIO;
 211
 212        return err;
 213}
 214
 215int ocfs2_read_inline_data(struct inode *inode, struct page *page,
 216                           struct buffer_head *di_bh)
 217{
 218        void *kaddr;
 219        loff_t size;
 220        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 221
 222        if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
 223                ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag",
 224                            (unsigned long long)OCFS2_I(inode)->ip_blkno);
 225                return -EROFS;
 226        }
 227
 228        size = i_size_read(inode);
 229
 230        if (size > PAGE_CACHE_SIZE ||
 231            size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
 232                ocfs2_error(inode->i_sb,
 233                            "Inode %llu has with inline data has bad size: %Lu",
 234                            (unsigned long long)OCFS2_I(inode)->ip_blkno,
 235                            (unsigned long long)size);
 236                return -EROFS;
 237        }
 238
 239        kaddr = kmap_atomic(page);
 240        if (size)
 241                memcpy(kaddr, di->id2.i_data.id_data, size);
 242        /* Clear the remaining part of the page */
 243        memset(kaddr + size, 0, PAGE_CACHE_SIZE - size);
 244        flush_dcache_page(page);
 245        kunmap_atomic(kaddr);
 246
 247        SetPageUptodate(page);
 248
 249        return 0;
 250}
 251
 252static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
 253{
 254        int ret;
 255        struct buffer_head *di_bh = NULL;
 256
 257        BUG_ON(!PageLocked(page));
 258        BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
 259
 260        ret = ocfs2_read_inode_block(inode, &di_bh);
 261        if (ret) {
 262                mlog_errno(ret);
 263                goto out;
 264        }
 265
 266        ret = ocfs2_read_inline_data(inode, page, di_bh);
 267out:
 268        unlock_page(page);
 269
 270        brelse(di_bh);
 271        return ret;
 272}
 273
 274static int ocfs2_readpage(struct file *file, struct page *page)
 275{
 276        struct inode *inode = page->mapping->host;
 277        struct ocfs2_inode_info *oi = OCFS2_I(inode);
 278        loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
 279        int ret, unlock = 1;
 280
 281        trace_ocfs2_readpage((unsigned long long)oi->ip_blkno,
 282                             (page ? page->index : 0));
 283
 284        ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
 285        if (ret != 0) {
 286                if (ret == AOP_TRUNCATED_PAGE)
 287                        unlock = 0;
 288                mlog_errno(ret);
 289                goto out;
 290        }
 291
 292        if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
 293                /*
 294                 * Unlock the page and cycle ip_alloc_sem so that we don't
 295                 * busyloop waiting for ip_alloc_sem to unlock
 296                 */
 297                ret = AOP_TRUNCATED_PAGE;
 298                unlock_page(page);
 299                unlock = 0;
 300                down_read(&oi->ip_alloc_sem);
 301                up_read(&oi->ip_alloc_sem);
 302                goto out_inode_unlock;
 303        }
 304
 305        /*
 306         * i_size might have just been updated as we grabed the meta lock.  We
 307         * might now be discovering a truncate that hit on another node.
 308         * block_read_full_page->get_block freaks out if it is asked to read
 309         * beyond the end of a file, so we check here.  Callers
 310         * (generic_file_read, vm_ops->fault) are clever enough to check i_size
 311         * and notice that the page they just read isn't needed.
 312         *
 313         * XXX sys_readahead() seems to get that wrong?
 314         */
 315        if (start >= i_size_read(inode)) {
 316                zero_user(page, 0, PAGE_SIZE);
 317                SetPageUptodate(page);
 318                ret = 0;
 319                goto out_alloc;
 320        }
 321
 322        if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 323                ret = ocfs2_readpage_inline(inode, page);
 324        else
 325                ret = block_read_full_page(page, ocfs2_get_block);
 326        unlock = 0;
 327
 328out_alloc:
 329        up_read(&OCFS2_I(inode)->ip_alloc_sem);
 330out_inode_unlock:
 331        ocfs2_inode_unlock(inode, 0);
 332out:
 333        if (unlock)
 334                unlock_page(page);
 335        return ret;
 336}
 337
 338/*
 339 * This is used only for read-ahead. Failures or difficult to handle
 340 * situations are safe to ignore.
 341 *
 342 * Right now, we don't bother with BH_Boundary - in-inode extent lists
 343 * are quite large (243 extents on 4k blocks), so most inodes don't
 344 * grow out to a tree. If need be, detecting boundary extents could
 345 * trivially be added in a future version of ocfs2_get_block().
 346 */
 347static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
 348                           struct list_head *pages, unsigned nr_pages)
 349{
 350        int ret, err = -EIO;
 351        struct inode *inode = mapping->host;
 352        struct ocfs2_inode_info *oi = OCFS2_I(inode);
 353        loff_t start;
 354        struct page *last;
 355
 356        /*
 357         * Use the nonblocking flag for the dlm code to avoid page
 358         * lock inversion, but don't bother with retrying.
 359         */
 360        ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
 361        if (ret)
 362                return err;
 363
 364        if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
 365                ocfs2_inode_unlock(inode, 0);
 366                return err;
 367        }
 368
 369        /*
 370         * Don't bother with inline-data. There isn't anything
 371         * to read-ahead in that case anyway...
 372         */
 373        if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 374                goto out_unlock;
 375
 376        /*
 377         * Check whether a remote node truncated this file - we just
 378         * drop out in that case as it's not worth handling here.
 379         */
 380        last = list_entry(pages->prev, struct page, lru);
 381        start = (loff_t)last->index << PAGE_CACHE_SHIFT;
 382        if (start >= i_size_read(inode))
 383                goto out_unlock;
 384
 385        err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
 386
 387out_unlock:
 388        up_read(&oi->ip_alloc_sem);
 389        ocfs2_inode_unlock(inode, 0);
 390
 391        return err;
 392}
 393
 394/* Note: Because we don't support holes, our allocation has
 395 * already happened (allocation writes zeros to the file data)
 396 * so we don't have to worry about ordered writes in
 397 * ocfs2_writepage.
 398 *
 399 * ->writepage is called during the process of invalidating the page cache
 400 * during blocked lock processing.  It can't block on any cluster locks
 401 * to during block mapping.  It's relying on the fact that the block
 402 * mapping can't have disappeared under the dirty pages that it is
 403 * being asked to write back.
 404 */
 405static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
 406{
 407        trace_ocfs2_writepage(
 408                (unsigned long long)OCFS2_I(page->mapping->host)->ip_blkno,
 409                page->index);
 410
 411        return block_write_full_page(page, ocfs2_get_block, wbc);
 412}
 413
 414/* Taken from ext3. We don't necessarily need the full blown
 415 * functionality yet, but IMHO it's better to cut and paste the whole
 416 * thing so we can avoid introducing our own bugs (and easily pick up
 417 * their fixes when they happen) --Mark */
 418int walk_page_buffers(  handle_t *handle,
 419                        struct buffer_head *head,
 420                        unsigned from,
 421                        unsigned to,
 422                        int *partial,
 423                        int (*fn)(      handle_t *handle,
 424                                        struct buffer_head *bh))
 425{
 426        struct buffer_head *bh;
 427        unsigned block_start, block_end;
 428        unsigned blocksize = head->b_size;
 429        int err, ret = 0;
 430        struct buffer_head *next;
 431
 432        for (   bh = head, block_start = 0;
 433                ret == 0 && (bh != head || !block_start);
 434                block_start = block_end, bh = next)
 435        {
 436                next = bh->b_this_page;
 437                block_end = block_start + blocksize;
 438                if (block_end <= from || block_start >= to) {
 439                        if (partial && !buffer_uptodate(bh))
 440                                *partial = 1;
 441                        continue;
 442                }
 443                err = (*fn)(handle, bh);
 444                if (!ret)
 445                        ret = err;
 446        }
 447        return ret;
 448}
 449
 450static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
 451{
 452        sector_t status;
 453        u64 p_blkno = 0;
 454        int err = 0;
 455        struct inode *inode = mapping->host;
 456
 457        trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno,
 458                         (unsigned long long)block);
 459
 460        /* We don't need to lock journal system files, since they aren't
 461         * accessed concurrently from multiple nodes.
 462         */
 463        if (!INODE_JOURNAL(inode)) {
 464                err = ocfs2_inode_lock(inode, NULL, 0);
 465                if (err) {
 466                        if (err != -ENOENT)
 467                                mlog_errno(err);
 468                        goto bail;
 469                }
 470                down_read(&OCFS2_I(inode)->ip_alloc_sem);
 471        }
 472
 473        if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
 474                err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
 475                                                  NULL);
 476
 477        if (!INODE_JOURNAL(inode)) {
 478                up_read(&OCFS2_I(inode)->ip_alloc_sem);
 479                ocfs2_inode_unlock(inode, 0);
 480        }
 481
 482        if (err) {
 483                mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
 484                     (unsigned long long)block);
 485                mlog_errno(err);
 486                goto bail;
 487        }
 488
 489bail:
 490        status = err ? 0 : p_blkno;
 491
 492        return status;
 493}
 494
 495/*
 496 * TODO: Make this into a generic get_blocks function.
 497 *
 498 * From do_direct_io in direct-io.c:
 499 *  "So what we do is to permit the ->get_blocks function to populate
 500 *   bh.b_size with the size of IO which is permitted at this offset and
 501 *   this i_blkbits."
 502 *
 503 * This function is called directly from get_more_blocks in direct-io.c.
 504 *
 505 * called like this: dio->get_blocks(dio->inode, fs_startblk,
 506 *                                      fs_count, map_bh, dio->rw == WRITE);
 507 *
 508 * Note that we never bother to allocate blocks here, and thus ignore the
 509 * create argument.
 510 */
 511static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
 512                                     struct buffer_head *bh_result, int create)
 513{
 514        int ret;
 515        u64 p_blkno, inode_blocks, contig_blocks;
 516        unsigned int ext_flags;
 517        unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
 518        unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
 519
 520        /* This function won't even be called if the request isn't all
 521         * nicely aligned and of the right size, so there's no need
 522         * for us to check any of that. */
 523
 524        inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
 525
 526        /* This figures out the size of the next contiguous block, and
 527         * our logical offset */
 528        ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
 529                                          &contig_blocks, &ext_flags);
 530        if (ret) {
 531                mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
 532                     (unsigned long long)iblock);
 533                ret = -EIO;
 534                goto bail;
 535        }
 536
 537        /* We should already CoW the refcounted extent in case of create. */
 538        BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED));
 539
 540        /*
 541         * get_more_blocks() expects us to describe a hole by clearing
 542         * the mapped bit on bh_result().
 543         *
 544         * Consider an unwritten extent as a hole.
 545         */
 546        if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 547                map_bh(bh_result, inode->i_sb, p_blkno);
 548        else
 549                clear_buffer_mapped(bh_result);
 550
 551        /* make sure we don't map more than max_blocks blocks here as
 552           that's all the kernel will handle at this point. */
 553        if (max_blocks < contig_blocks)
 554                contig_blocks = max_blocks;
 555        bh_result->b_size = contig_blocks << blocksize_bits;
 556bail:
 557        return ret;
 558}
 559
 560/*
 561 * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
 562 * particularly interested in the aio/dio case.  We use the rw_lock DLM lock
 563 * to protect io on one node from truncation on another.
 564 */
 565static void ocfs2_dio_end_io(struct kiocb *iocb,
 566                             loff_t offset,
 567                             ssize_t bytes,
 568                             void *private,
 569                             int ret,
 570                             bool is_async)
 571{
 572        struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
 573        int level;
 574        wait_queue_head_t *wq = ocfs2_ioend_wq(inode);
 575
 576        /* this io's submitter should not have unlocked this before we could */
 577        BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
 578
 579        if (ocfs2_iocb_is_sem_locked(iocb))
 580                ocfs2_iocb_clear_sem_locked(iocb);
 581
 582        if (ocfs2_iocb_is_unaligned_aio(iocb)) {
 583                ocfs2_iocb_clear_unaligned_aio(iocb);
 584
 585                if (atomic_dec_and_test(&OCFS2_I(inode)->ip_unaligned_aio) &&
 586                    waitqueue_active(wq)) {
 587                        wake_up_all(wq);
 588                }
 589        }
 590
 591        ocfs2_iocb_clear_rw_locked(iocb);
 592
 593        level = ocfs2_iocb_rw_locked_level(iocb);
 594        ocfs2_rw_unlock(inode, level);
 595
 596        if (is_async)
 597                aio_complete(iocb, ret, 0);
 598        inode_dio_done(inode);
 599}
 600
 601/*
 602 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
 603 * from ext3.  PageChecked() bits have been removed as OCFS2 does not
 604 * do journalled data.
 605 */
 606static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
 607{
 608        journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
 609
 610        jbd2_journal_invalidatepage(journal, page, offset);
 611}
 612
 613static int ocfs2_releasepage(struct page *page, gfp_t wait)
 614{
 615        journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
 616
 617        if (!page_has_buffers(page))
 618                return 0;
 619        return jbd2_journal_try_to_free_buffers(journal, page, wait);
 620}
 621
 622static ssize_t ocfs2_direct_IO(int rw,
 623                               struct kiocb *iocb,
 624                               const struct iovec *iov,
 625                               loff_t offset,
 626                               unsigned long nr_segs)
 627{
 628        struct file *file = iocb->ki_filp;
 629        struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
 630
 631        /*
 632         * Fallback to buffered I/O if we see an inode without
 633         * extents.
 634         */
 635        if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 636                return 0;
 637
 638        /* Fallback to buffered I/O if we are appending. */
 639        if (i_size_read(inode) <= offset)
 640                return 0;
 641
 642        return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
 643                                    iov, offset, nr_segs,
 644                                    ocfs2_direct_IO_get_blocks,
 645                                    ocfs2_dio_end_io, NULL, 0);
 646}
 647
 648static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
 649                                            u32 cpos,
 650                                            unsigned int *start,
 651                                            unsigned int *end)
 652{
 653        unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
 654
 655        if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
 656                unsigned int cpp;
 657
 658                cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
 659
 660                cluster_start = cpos % cpp;
 661                cluster_start = cluster_start << osb->s_clustersize_bits;
 662
 663                cluster_end = cluster_start + osb->s_clustersize;
 664        }
 665
 666        BUG_ON(cluster_start > PAGE_SIZE);
 667        BUG_ON(cluster_end > PAGE_SIZE);
 668
 669        if (start)
 670                *start = cluster_start;
 671        if (end)
 672                *end = cluster_end;
 673}
 674
 675/*
 676 * 'from' and 'to' are the region in the page to avoid zeroing.
 677 *
 678 * If pagesize > clustersize, this function will avoid zeroing outside
 679 * of the cluster boundary.
 680 *
 681 * from == to == 0 is code for "zero the entire cluster region"
 682 */
 683static void ocfs2_clear_page_regions(struct page *page,
 684                                     struct ocfs2_super *osb, u32 cpos,
 685                                     unsigned from, unsigned to)
 686{
 687        void *kaddr;
 688        unsigned int cluster_start, cluster_end;
 689
 690        ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
 691
 692        kaddr = kmap_atomic(page);
 693
 694        if (from || to) {
 695                if (from > cluster_start)
 696                        memset(kaddr + cluster_start, 0, from - cluster_start);
 697                if (to < cluster_end)
 698                        memset(kaddr + to, 0, cluster_end - to);
 699        } else {
 700                memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
 701        }
 702
 703        kunmap_atomic(kaddr);
 704}
 705
 706/*
 707 * Nonsparse file systems fully allocate before we get to the write
 708 * code. This prevents ocfs2_write() from tagging the write as an
 709 * allocating one, which means ocfs2_map_page_blocks() might try to
 710 * read-in the blocks at the tail of our file. Avoid reading them by
 711 * testing i_size against each block offset.
 712 */
 713static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
 714                                 unsigned int block_start)
 715{
 716        u64 offset = page_offset(page) + block_start;
 717
 718        if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
 719                return 1;
 720
 721        if (i_size_read(inode) > offset)
 722                return 1;
 723
 724        return 0;
 725}
 726
 727/*
 728 * Some of this taken from __block_write_begin(). We already have our
 729 * mapping by now though, and the entire write will be allocating or
 730 * it won't, so not much need to use BH_New.
 731 *
 732 * This will also skip zeroing, which is handled externally.
 733 */
 734int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
 735                          struct inode *inode, unsigned int from,
 736                          unsigned int to, int new)
 737{
 738        int ret = 0;
 739        struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
 740        unsigned int block_end, block_start;
 741        unsigned int bsize = 1 << inode->i_blkbits;
 742
 743        if (!page_has_buffers(page))
 744                create_empty_buffers(page, bsize, 0);
 745
 746        head = page_buffers(page);
 747        for (bh = head, block_start = 0; bh != head || !block_start;
 748             bh = bh->b_this_page, block_start += bsize) {
 749                block_end = block_start + bsize;
 750
 751                clear_buffer_new(bh);
 752
 753                /*
 754                 * Ignore blocks outside of our i/o range -
 755                 * they may belong to unallocated clusters.
 756                 */
 757                if (block_start >= to || block_end <= from) {
 758                        if (PageUptodate(page))
 759                                set_buffer_uptodate(bh);
 760                        continue;
 761                }
 762
 763                /*
 764                 * For an allocating write with cluster size >= page
 765                 * size, we always write the entire page.
 766                 */
 767                if (new)
 768                        set_buffer_new(bh);
 769
 770                if (!buffer_mapped(bh)) {
 771                        map_bh(bh, inode->i_sb, *p_blkno);
 772                        unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
 773                }
 774
 775                if (PageUptodate(page)) {
 776                        if (!buffer_uptodate(bh))
 777                                set_buffer_uptodate(bh);
 778                } else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
 779                           !buffer_new(bh) &&
 780                           ocfs2_should_read_blk(inode, page, block_start) &&
 781                           (block_start < from || block_end > to)) {
 782                        ll_rw_block(READ, 1, &bh);
 783                        *wait_bh++=bh;
 784                }
 785
 786                *p_blkno = *p_blkno + 1;
 787        }
 788
 789        /*
 790         * If we issued read requests - let them complete.
 791         */
 792        while(wait_bh > wait) {
 793                wait_on_buffer(*--wait_bh);
 794                if (!buffer_uptodate(*wait_bh))
 795                        ret = -EIO;
 796        }
 797
 798        if (ret == 0 || !new)
 799                return ret;
 800
 801        /*
 802         * If we get -EIO above, zero out any newly allocated blocks
 803         * to avoid exposing stale data.
 804         */
 805        bh = head;
 806        block_start = 0;
 807        do {
 808                block_end = block_start + bsize;
 809                if (block_end <= from)
 810                        goto next_bh;
 811                if (block_start >= to)
 812                        break;
 813
 814                zero_user(page, block_start, bh->b_size);
 815                set_buffer_uptodate(bh);
 816                mark_buffer_dirty(bh);
 817
 818next_bh:
 819                block_start = block_end;
 820                bh = bh->b_this_page;
 821        } while (bh != head);
 822
 823        return ret;
 824}
 825
 826#if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
 827#define OCFS2_MAX_CTXT_PAGES    1
 828#else
 829#define OCFS2_MAX_CTXT_PAGES    (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
 830#endif
 831
 832#define OCFS2_MAX_CLUSTERS_PER_PAGE     (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
 833
 834/*
 835 * Describe the state of a single cluster to be written to.
 836 */
 837struct ocfs2_write_cluster_desc {
 838        u32             c_cpos;
 839        u32             c_phys;
 840        /*
 841         * Give this a unique field because c_phys eventually gets
 842         * filled.
 843         */
 844        unsigned        c_new;
 845        unsigned        c_unwritten;
 846        unsigned        c_needs_zero;
 847};
 848
 849struct ocfs2_write_ctxt {
 850        /* Logical cluster position / len of write */
 851        u32                             w_cpos;
 852        u32                             w_clen;
 853
 854        /* First cluster allocated in a nonsparse extend */
 855        u32                             w_first_new_cpos;
 856
 857        struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
 858
 859        /*
 860         * This is true if page_size > cluster_size.
 861         *
 862         * It triggers a set of special cases during write which might
 863         * have to deal with allocating writes to partial pages.
 864         */
 865        unsigned int                    w_large_pages;
 866
 867        /*
 868         * Pages involved in this write.
 869         *
 870         * w_target_page is the page being written to by the user.
 871         *
 872         * w_pages is an array of pages which always contains
 873         * w_target_page, and in the case of an allocating write with
 874         * page_size < cluster size, it will contain zero'd and mapped
 875         * pages adjacent to w_target_page which need to be written
 876         * out in so that future reads from that region will get
 877         * zero's.
 878         */
 879        unsigned int                    w_num_pages;
 880        struct page                     *w_pages[OCFS2_MAX_CTXT_PAGES];
 881        struct page                     *w_target_page;
 882
 883        /*
 884         * w_target_locked is used for page_mkwrite path indicating no unlocking
 885         * against w_target_page in ocfs2_write_end_nolock.
 886         */
 887        unsigned int                    w_target_locked:1;
 888
 889        /*
 890         * ocfs2_write_end() uses this to know what the real range to
 891         * write in the target should be.
 892         */
 893        unsigned int                    w_target_from;
 894        unsigned int                    w_target_to;
 895
 896        /*
 897         * We could use journal_current_handle() but this is cleaner,
 898         * IMHO -Mark
 899         */
 900        handle_t                        *w_handle;
 901
 902        struct buffer_head              *w_di_bh;
 903
 904        struct ocfs2_cached_dealloc_ctxt w_dealloc;
 905};
 906
 907void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
 908{
 909        int i;
 910
 911        for(i = 0; i < num_pages; i++) {
 912                if (pages[i]) {
 913                        unlock_page(pages[i]);
 914                        mark_page_accessed(pages[i]);
 915                        page_cache_release(pages[i]);
 916                }
 917        }
 918}
 919
 920static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
 921{
 922        int i;
 923
 924        /*
 925         * w_target_locked is only set to true in the page_mkwrite() case.
 926         * The intent is to allow us to lock the target page from write_begin()
 927         * to write_end(). The caller must hold a ref on w_target_page.
 928         */
 929        if (wc->w_target_locked) {
 930                BUG_ON(!wc->w_target_page);
 931                for (i = 0; i < wc->w_num_pages; i++) {
 932                        if (wc->w_target_page == wc->w_pages[i]) {
 933                                wc->w_pages[i] = NULL;
 934                                break;
 935                        }
 936                }
 937                mark_page_accessed(wc->w_target_page);
 938                page_cache_release(wc->w_target_page);
 939        }
 940        ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
 941
 942        brelse(wc->w_di_bh);
 943        kfree(wc);
 944}
 945
 946static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
 947                                  struct ocfs2_super *osb, loff_t pos,
 948                                  unsigned len, struct buffer_head *di_bh)
 949{
 950        u32 cend;
 951        struct ocfs2_write_ctxt *wc;
 952
 953        wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
 954        if (!wc)
 955                return -ENOMEM;
 956
 957        wc->w_cpos = pos >> osb->s_clustersize_bits;
 958        wc->w_first_new_cpos = UINT_MAX;
 959        cend = (pos + len - 1) >> osb->s_clustersize_bits;
 960        wc->w_clen = cend - wc->w_cpos + 1;
 961        get_bh(di_bh);
 962        wc->w_di_bh = di_bh;
 963
 964        if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
 965                wc->w_large_pages = 1;
 966        else
 967                wc->w_large_pages = 0;
 968
 969        ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
 970
 971        *wcp = wc;
 972
 973        return 0;
 974}
 975
 976/*
 977 * If a page has any new buffers, zero them out here, and mark them uptodate
 978 * and dirty so they'll be written out (in order to prevent uninitialised
 979 * block data from leaking). And clear the new bit.
 980 */
 981static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
 982{
 983        unsigned int block_start, block_end;
 984        struct buffer_head *head, *bh;
 985
 986        BUG_ON(!PageLocked(page));
 987        if (!page_has_buffers(page))
 988                return;
 989
 990        bh = head = page_buffers(page);
 991        block_start = 0;
 992        do {
 993                block_end = block_start + bh->b_size;
 994
 995                if (buffer_new(bh)) {
 996                        if (block_end > from && block_start < to) {
 997                                if (!PageUptodate(page)) {
 998                                        unsigned start, end;
 999
1000                                        start = max(from, block_start);
1001                                        end = min(to, block_end);
1002
1003                                        zero_user_segment(page, start, end);
1004                                        set_buffer_uptodate(bh);
1005                                }
1006
1007                                clear_buffer_new(bh);
1008                                mark_buffer_dirty(bh);
1009                        }
1010                }
1011
1012                block_start = block_end;
1013                bh = bh->b_this_page;
1014        } while (bh != head);
1015}
1016
1017/*
1018 * Only called when we have a failure during allocating write to write
1019 * zero's to the newly allocated region.
1020 */
1021static void ocfs2_write_failure(struct inode *inode,
1022                                struct ocfs2_write_ctxt *wc,
1023                                loff_t user_pos, unsigned user_len)
1024{
1025        int i;
1026        unsigned from = user_pos & (PAGE_CACHE_SIZE - 1),
1027                to = user_pos + user_len;
1028        struct page *tmppage;
1029
1030        ocfs2_zero_new_buffers(wc->w_target_page, from, to);
1031
1032        for(i = 0; i < wc->w_num_pages; i++) {
1033                tmppage = wc->w_pages[i];
1034
1035                if (page_has_buffers(tmppage)) {
1036                        if (ocfs2_should_order_data(inode))
1037                                ocfs2_jbd2_file_inode(wc->w_handle, inode);
1038
1039                        block_commit_write(tmppage, from, to);
1040                }
1041        }
1042}
1043
1044static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
1045                                        struct ocfs2_write_ctxt *wc,
1046                                        struct page *page, u32 cpos,
1047                                        loff_t user_pos, unsigned user_len,
1048                                        int new)
1049{
1050        int ret;
1051        unsigned int map_from = 0, map_to = 0;
1052        unsigned int cluster_start, cluster_end;
1053        unsigned int user_data_from = 0, user_data_to = 0;
1054
1055        ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
1056                                        &cluster_start, &cluster_end);
1057
1058        /* treat the write as new if the a hole/lseek spanned across
1059         * the page boundary.
1060         */
1061        new = new | ((i_size_read(inode) <= page_offset(page)) &&
1062                        (page_offset(page) <= user_pos));
1063
1064        if (page == wc->w_target_page) {
1065                map_from = user_pos & (PAGE_CACHE_SIZE - 1);
1066                map_to = map_from + user_len;
1067
1068                if (new)
1069                        ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1070                                                    cluster_start, cluster_end,
1071                                                    new);
1072                else
1073                        ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1074                                                    map_from, map_to, new);
1075                if (ret) {
1076                        mlog_errno(ret);
1077                        goto out;
1078                }
1079
1080                user_data_from = map_from;
1081                user_data_to = map_to;
1082                if (new) {
1083                        map_from = cluster_start;
1084                        map_to = cluster_end;
1085                }
1086        } else {
1087                /*
1088                 * If we haven't allocated the new page yet, we
1089                 * shouldn't be writing it out without copying user
1090                 * data. This is likely a math error from the caller.
1091                 */
1092                BUG_ON(!new);
1093
1094                map_from = cluster_start;
1095                map_to = cluster_end;
1096
1097                ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1098                                            cluster_start, cluster_end, new);
1099                if (ret) {
1100                        mlog_errno(ret);
1101                        goto out;
1102                }
1103        }
1104
1105        /*
1106         * Parts of newly allocated pages need to be zero'd.
1107         *
1108         * Above, we have also rewritten 'to' and 'from' - as far as
1109         * the rest of the function is concerned, the entire cluster
1110         * range inside of a page needs to be written.
1111         *
1112         * We can skip this if the page is up to date - it's already
1113         * been zero'd from being read in as a hole.
1114         */
1115        if (new && !PageUptodate(page))
1116                ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1117                                         cpos, user_data_from, user_data_to);
1118
1119        flush_dcache_page(page);
1120
1121out:
1122        return ret;
1123}
1124
1125/*
1126 * This function will only grab one clusters worth of pages.
1127 */
1128static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1129                                      struct ocfs2_write_ctxt *wc,
1130                                      u32 cpos, loff_t user_pos,
1131                                      unsigned user_len, int new,
1132                                      struct page *mmap_page)
1133{
1134        int ret = 0, i;
1135        unsigned long start, target_index, end_index, index;
1136        struct inode *inode = mapping->host;
1137        loff_t last_byte;
1138
1139        target_index = user_pos >> PAGE_CACHE_SHIFT;
1140
1141        /*
1142         * Figure out how many pages we'll be manipulating here. For
1143         * non allocating write, we just change the one
1144         * page. Otherwise, we'll need a whole clusters worth.  If we're
1145         * writing past i_size, we only need enough pages to cover the
1146         * last page of the write.
1147         */
1148        if (new) {
1149                wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1150                start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1151                /*
1152                 * We need the index *past* the last page we could possibly
1153                 * touch.  This is the page past the end of the write or
1154                 * i_size, whichever is greater.
1155                 */
1156                last_byte = max(user_pos + user_len, i_size_read(inode));
1157                BUG_ON(last_byte < 1);
1158                end_index = ((last_byte - 1) >> PAGE_CACHE_SHIFT) + 1;
1159                if ((start + wc->w_num_pages) > end_index)
1160                        wc->w_num_pages = end_index - start;
1161        } else {
1162                wc->w_num_pages = 1;
1163                start = target_index;
1164        }
1165
1166        for(i = 0; i < wc->w_num_pages; i++) {
1167                index = start + i;
1168
1169                if (index == target_index && mmap_page) {
1170                        /*
1171                         * ocfs2_pagemkwrite() is a little different
1172                         * and wants us to directly use the page
1173                         * passed in.
1174                         */
1175                        lock_page(mmap_page);
1176
1177                        /* Exit and let the caller retry */
1178                        if (mmap_page->mapping != mapping) {
1179                                WARN_ON(mmap_page->mapping);
1180                                unlock_page(mmap_page);
1181                                ret = -EAGAIN;
1182                                goto out;
1183                        }
1184
1185                        page_cache_get(mmap_page);
1186                        wc->w_pages[i] = mmap_page;
1187                        wc->w_target_locked = true;
1188                } else {
1189                        wc->w_pages[i] = find_or_create_page(mapping, index,
1190                                                             GFP_NOFS);
1191                        if (!wc->w_pages[i]) {
1192                                ret = -ENOMEM;
1193                                mlog_errno(ret);
1194                                goto out;
1195                        }
1196                }
1197
1198                if (index == target_index)
1199                        wc->w_target_page = wc->w_pages[i];
1200        }
1201out:
1202        if (ret)
1203                wc->w_target_locked = false;
1204        return ret;
1205}
1206
1207/*
1208 * Prepare a single cluster for write one cluster into the file.
1209 */
1210static int ocfs2_write_cluster(struct address_space *mapping,
1211                               u32 phys, unsigned int unwritten,
1212                               unsigned int should_zero,
1213                               struct ocfs2_alloc_context *data_ac,
1214                               struct ocfs2_alloc_context *meta_ac,
1215                               struct ocfs2_write_ctxt *wc, u32 cpos,
1216                               loff_t user_pos, unsigned user_len)
1217{
1218        int ret, i, new;
1219        u64 v_blkno, p_blkno;
1220        struct inode *inode = mapping->host;
1221        struct ocfs2_extent_tree et;
1222
1223        new = phys == 0 ? 1 : 0;
1224        if (new) {
1225                u32 tmp_pos;
1226
1227                /*
1228                 * This is safe to call with the page locks - it won't take
1229                 * any additional semaphores or cluster locks.
1230                 */
1231                tmp_pos = cpos;
1232                ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1233                                           &tmp_pos, 1, 0, wc->w_di_bh,
1234                                           wc->w_handle, data_ac,
1235                                           meta_ac, NULL);
1236                /*
1237                 * This shouldn't happen because we must have already
1238                 * calculated the correct meta data allocation required. The
1239                 * internal tree allocation code should know how to increase
1240                 * transaction credits itself.
1241                 *
1242                 * If need be, we could handle -EAGAIN for a
1243                 * RESTART_TRANS here.
1244                 */
1245                mlog_bug_on_msg(ret == -EAGAIN,
1246                                "Inode %llu: EAGAIN return during allocation.\n",
1247                                (unsigned long long)OCFS2_I(inode)->ip_blkno);
1248                if (ret < 0) {
1249                        mlog_errno(ret);
1250                        goto out;
1251                }
1252        } else if (unwritten) {
1253                ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1254                                              wc->w_di_bh);
1255                ret = ocfs2_mark_extent_written(inode, &et,
1256                                                wc->w_handle, cpos, 1, phys,
1257                                                meta_ac, &wc->w_dealloc);
1258                if (ret < 0) {
1259                        mlog_errno(ret);
1260                        goto out;
1261                }
1262        }
1263
1264        if (should_zero)
1265                v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
1266        else
1267                v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
1268
1269        /*
1270         * The only reason this should fail is due to an inability to
1271         * find the extent added.
1272         */
1273        ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
1274                                          NULL);
1275        if (ret < 0) {
1276                ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
1277                            "at logical block %llu",
1278                            (unsigned long long)OCFS2_I(inode)->ip_blkno,
1279                            (unsigned long long)v_blkno);
1280                goto out;
1281        }
1282
1283        BUG_ON(p_blkno == 0);
1284
1285        for(i = 0; i < wc->w_num_pages; i++) {
1286                int tmpret;
1287
1288                tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1289                                                      wc->w_pages[i], cpos,
1290                                                      user_pos, user_len,
1291                                                      should_zero);
1292                if (tmpret) {
1293                        mlog_errno(tmpret);
1294                        if (ret == 0)
1295                                ret = tmpret;
1296                }
1297        }
1298
1299        /*
1300         * We only have cleanup to do in case of allocating write.
1301         */
1302        if (ret && new)
1303                ocfs2_write_failure(inode, wc, user_pos, user_len);
1304
1305out:
1306
1307        return ret;
1308}
1309
1310static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1311                                       struct ocfs2_alloc_context *data_ac,
1312                                       struct ocfs2_alloc_context *meta_ac,
1313                                       struct ocfs2_write_ctxt *wc,
1314                                       loff_t pos, unsigned len)
1315{
1316        int ret, i;
1317        loff_t cluster_off;
1318        unsigned int local_len = len;
1319        struct ocfs2_write_cluster_desc *desc;
1320        struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1321
1322        for (i = 0; i < wc->w_clen; i++) {
1323                desc = &wc->w_desc[i];
1324
1325                /*
1326                 * We have to make sure that the total write passed in
1327                 * doesn't extend past a single cluster.
1328                 */
1329                local_len = len;
1330                cluster_off = pos & (osb->s_clustersize - 1);
1331                if ((cluster_off + local_len) > osb->s_clustersize)
1332                        local_len = osb->s_clustersize - cluster_off;
1333
1334                ret = ocfs2_write_cluster(mapping, desc->c_phys,
1335                                          desc->c_unwritten,
1336                                          desc->c_needs_zero,
1337                                          data_ac, meta_ac,
1338                                          wc, desc->c_cpos, pos, local_len);
1339                if (ret) {
1340                        mlog_errno(ret);
1341                        goto out;
1342                }
1343
1344                len -= local_len;
1345                pos += local_len;
1346        }
1347
1348        ret = 0;
1349out:
1350        return ret;
1351}
1352
1353/*
1354 * ocfs2_write_end() wants to know which parts of the target page it
1355 * should complete the write on. It's easiest to compute them ahead of
1356 * time when a more complete view of the write is available.
1357 */
1358static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1359                                        struct ocfs2_write_ctxt *wc,
1360                                        loff_t pos, unsigned len, int alloc)
1361{
1362        struct ocfs2_write_cluster_desc *desc;
1363
1364        wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
1365        wc->w_target_to = wc->w_target_from + len;
1366
1367        if (alloc == 0)
1368                return;
1369
1370        /*
1371         * Allocating write - we may have different boundaries based
1372         * on page size and cluster size.
1373         *
1374         * NOTE: We can no longer compute one value from the other as
1375         * the actual write length and user provided length may be
1376         * different.
1377         */
1378
1379        if (wc->w_large_pages) {
1380                /*
1381                 * We only care about the 1st and last cluster within
1382                 * our range and whether they should be zero'd or not. Either
1383                 * value may be extended out to the start/end of a
1384                 * newly allocated cluster.
1385                 */
1386                desc = &wc->w_desc[0];
1387                if (desc->c_needs_zero)
1388                        ocfs2_figure_cluster_boundaries(osb,
1389                                                        desc->c_cpos,
1390                                                        &wc->w_target_from,
1391                                                        NULL);
1392
1393                desc = &wc->w_desc[wc->w_clen - 1];
1394                if (desc->c_needs_zero)
1395                        ocfs2_figure_cluster_boundaries(osb,
1396                                                        desc->c_cpos,
1397                                                        NULL,
1398                                                        &wc->w_target_to);
1399        } else {
1400                wc->w_target_from = 0;
1401                wc->w_target_to = PAGE_CACHE_SIZE;
1402        }
1403}
1404
1405/*
1406 * Populate each single-cluster write descriptor in the write context
1407 * with information about the i/o to be done.
1408 *
1409 * Returns the number of clusters that will have to be allocated, as
1410 * well as a worst case estimate of the number of extent records that
1411 * would have to be created during a write to an unwritten region.
1412 */
1413static int ocfs2_populate_write_desc(struct inode *inode,
1414                                     struct ocfs2_write_ctxt *wc,
1415                                     unsigned int *clusters_to_alloc,
1416                                     unsigned int *extents_to_split)
1417{
1418        int ret;
1419        struct ocfs2_write_cluster_desc *desc;
1420        unsigned int num_clusters = 0;
1421        unsigned int ext_flags = 0;
1422        u32 phys = 0;
1423        int i;
1424
1425        *clusters_to_alloc = 0;
1426        *extents_to_split = 0;
1427
1428        for (i = 0; i < wc->w_clen; i++) {
1429                desc = &wc->w_desc[i];
1430                desc->c_cpos = wc->w_cpos + i;
1431
1432                if (num_clusters == 0) {
1433                        /*
1434                         * Need to look up the next extent record.
1435                         */
1436                        ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1437                                                 &num_clusters, &ext_flags);
1438                        if (ret) {
1439                                mlog_errno(ret);
1440                                goto out;
1441                        }
1442
1443                        /* We should already CoW the refcountd extent. */
1444                        BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1445
1446                        /*
1447                         * Assume worst case - that we're writing in
1448                         * the middle of the extent.
1449                         *
1450                         * We can assume that the write proceeds from
1451                         * left to right, in which case the extent
1452                         * insert code is smart enough to coalesce the
1453                         * next splits into the previous records created.
1454                         */
1455                        if (ext_flags & OCFS2_EXT_UNWRITTEN)
1456                                *extents_to_split = *extents_to_split + 2;
1457                } else if (phys) {
1458                        /*
1459                         * Only increment phys if it doesn't describe
1460                         * a hole.
1461                         */
1462                        phys++;
1463                }
1464
1465                /*
1466                 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1467                 * file that got extended.  w_first_new_cpos tells us
1468                 * where the newly allocated clusters are so we can
1469                 * zero them.
1470                 */
1471                if (desc->c_cpos >= wc->w_first_new_cpos) {
1472                        BUG_ON(phys == 0);
1473                        desc->c_needs_zero = 1;
1474                }
1475
1476                desc->c_phys = phys;
1477                if (phys == 0) {
1478                        desc->c_new = 1;
1479                        desc->c_needs_zero = 1;
1480                        *clusters_to_alloc = *clusters_to_alloc + 1;
1481                }
1482
1483                if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1484                        desc->c_unwritten = 1;
1485                        desc->c_needs_zero = 1;
1486                }
1487
1488                num_clusters--;
1489        }
1490
1491        ret = 0;
1492out:
1493        return ret;
1494}
1495
1496static int ocfs2_write_begin_inline(struct address_space *mapping,
1497                                    struct inode *inode,
1498                                    struct ocfs2_write_ctxt *wc)
1499{
1500        int ret;
1501        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1502        struct page *page;
1503        handle_t *handle;
1504        struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1505
1506        page = find_or_create_page(mapping, 0, GFP_NOFS);
1507        if (!page) {
1508                ret = -ENOMEM;
1509                mlog_errno(ret);
1510                goto out;
1511        }
1512        /*
1513         * If we don't set w_num_pages then this page won't get unlocked
1514         * and freed on cleanup of the write context.
1515         */
1516        wc->w_pages[0] = wc->w_target_page = page;
1517        wc->w_num_pages = 1;
1518
1519        handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1520        if (IS_ERR(handle)) {
1521                ret = PTR_ERR(handle);
1522                mlog_errno(ret);
1523                goto out;
1524        }
1525
1526        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1527                                      OCFS2_JOURNAL_ACCESS_WRITE);
1528        if (ret) {
1529                ocfs2_commit_trans(osb, handle);
1530
1531                mlog_errno(ret);
1532                goto out;
1533        }
1534
1535        if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1536                ocfs2_set_inode_data_inline(inode, di);
1537
1538        if (!PageUptodate(page)) {
1539                ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1540                if (ret) {
1541                        ocfs2_commit_trans(osb, handle);
1542
1543                        goto out;
1544                }
1545        }
1546
1547        wc->w_handle = handle;
1548out:
1549        return ret;
1550}
1551
1552int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1553{
1554        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1555
1556        if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1557                return 1;
1558        return 0;
1559}
1560
1561static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1562                                          struct inode *inode, loff_t pos,
1563                                          unsigned len, struct page *mmap_page,
1564                                          struct ocfs2_write_ctxt *wc)
1565{
1566        int ret, written = 0;
1567        loff_t end = pos + len;
1568        struct ocfs2_inode_info *oi = OCFS2_I(inode);
1569        struct ocfs2_dinode *di = NULL;
1570
1571        trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1572                                             len, (unsigned long long)pos,
1573                                             oi->ip_dyn_features);
1574
1575        /*
1576         * Handle inodes which already have inline data 1st.
1577         */
1578        if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1579                if (mmap_page == NULL &&
1580                    ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1581                        goto do_inline_write;
1582
1583                /*
1584                 * The write won't fit - we have to give this inode an
1585                 * inline extent list now.
1586                 */
1587                ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1588                if (ret)
1589                        mlog_errno(ret);
1590                goto out;
1591        }
1592
1593        /*
1594         * Check whether the inode can accept inline data.
1595         */
1596        if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1597                return 0;
1598
1599        /*
1600         * Check whether the write can fit.
1601         */
1602        di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1603        if (mmap_page ||
1604            end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1605                return 0;
1606
1607do_inline_write:
1608        ret = ocfs2_write_begin_inline(mapping, inode, wc);
1609        if (ret) {
1610                mlog_errno(ret);
1611                goto out;
1612        }
1613
1614        /*
1615         * This signals to the caller that the data can be written
1616         * inline.
1617         */
1618        written = 1;
1619out:
1620        return written ? written : ret;
1621}
1622
1623/*
1624 * This function only does anything for file systems which can't
1625 * handle sparse files.
1626 *
1627 * What we want to do here is fill in any hole between the current end
1628 * of allocation and the end of our write. That way the rest of the
1629 * write path can treat it as an non-allocating write, which has no
1630 * special case code for sparse/nonsparse files.
1631 */
1632static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1633                                        struct buffer_head *di_bh,
1634                                        loff_t pos, unsigned len,
1635                                        struct ocfs2_write_ctxt *wc)
1636{
1637        int ret;
1638        loff_t newsize = pos + len;
1639
1640        BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1641
1642        if (newsize <= i_size_read(inode))
1643                return 0;
1644
1645        ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1646        if (ret)
1647                mlog_errno(ret);
1648
1649        wc->w_first_new_cpos =
1650                ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1651
1652        return ret;
1653}
1654
1655static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1656                           loff_t pos)
1657{
1658        int ret = 0;
1659
1660        BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1661        if (pos > i_size_read(inode))
1662                ret = ocfs2_zero_extend(inode, di_bh, pos);
1663
1664        return ret;
1665}
1666
1667/*
1668 * Try to flush truncate logs if we can free enough clusters from it.
1669 * As for return value, "< 0" means error, "0" no space and "1" means
1670 * we have freed enough spaces and let the caller try to allocate again.
1671 */
1672static int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb,
1673                                          unsigned int needed)
1674{
1675        tid_t target;
1676        int ret = 0;
1677        unsigned int truncated_clusters;
1678
1679        mutex_lock(&osb->osb_tl_inode->i_mutex);
1680        truncated_clusters = osb->truncated_clusters;
1681        mutex_unlock(&osb->osb_tl_inode->i_mutex);
1682
1683        /*
1684         * Check whether we can succeed in allocating if we free
1685         * the truncate log.
1686         */
1687        if (truncated_clusters < needed)
1688                goto out;
1689
1690        ret = ocfs2_flush_truncate_log(osb);
1691        if (ret) {
1692                mlog_errno(ret);
1693                goto out;
1694        }
1695
1696        if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) {
1697                jbd2_log_wait_commit(osb->journal->j_journal, target);
1698                ret = 1;
1699        }
1700out:
1701        return ret;
1702}
1703
1704int ocfs2_write_begin_nolock(struct file *filp,
1705                             struct address_space *mapping,
1706                             loff_t pos, unsigned len, unsigned flags,
1707                             struct page **pagep, void **fsdata,
1708                             struct buffer_head *di_bh, struct page *mmap_page)
1709{
1710        int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1711        unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1712        struct ocfs2_write_ctxt *wc;
1713        struct inode *inode = mapping->host;
1714        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1715        struct ocfs2_dinode *di;
1716        struct ocfs2_alloc_context *data_ac = NULL;
1717        struct ocfs2_alloc_context *meta_ac = NULL;
1718        handle_t *handle;
1719        struct ocfs2_extent_tree et;
1720        int try_free = 1, ret1;
1721
1722try_again:
1723        ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
1724        if (ret) {
1725                mlog_errno(ret);
1726                return ret;
1727        }
1728
1729        if (ocfs2_supports_inline_data(osb)) {
1730                ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1731                                                     mmap_page, wc);
1732                if (ret == 1) {
1733                        ret = 0;
1734                        goto success;
1735                }
1736                if (ret < 0) {
1737                        mlog_errno(ret);
1738                        goto out;
1739                }
1740        }
1741
1742        if (ocfs2_sparse_alloc(osb))
1743                ret = ocfs2_zero_tail(inode, di_bh, pos);
1744        else
1745                ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos, len,
1746                                                   wc);
1747        if (ret) {
1748                mlog_errno(ret);
1749                goto out;
1750        }
1751
1752        ret = ocfs2_check_range_for_refcount(inode, pos, len);
1753        if (ret < 0) {
1754                mlog_errno(ret);
1755                goto out;
1756        } else if (ret == 1) {
1757                clusters_need = wc->w_clen;
1758                ret = ocfs2_refcount_cow(inode, filp, di_bh,
1759                                         wc->w_cpos, wc->w_clen, UINT_MAX);
1760                if (ret) {
1761                        mlog_errno(ret);
1762                        goto out;
1763                }
1764        }
1765
1766        ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1767                                        &extents_to_split);
1768        if (ret) {
1769                mlog_errno(ret);
1770                goto out;
1771        }
1772        clusters_need += clusters_to_alloc;
1773
1774        di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1775
1776        trace_ocfs2_write_begin_nolock(
1777                        (unsigned long long)OCFS2_I(inode)->ip_blkno,
1778                        (long long)i_size_read(inode),
1779                        le32_to_cpu(di->i_clusters),
1780                        pos, len, flags, mmap_page,
1781                        clusters_to_alloc, extents_to_split);
1782
1783        /*
1784         * We set w_target_from, w_target_to here so that
1785         * ocfs2_write_end() knows which range in the target page to
1786         * write out. An allocation requires that we write the entire
1787         * cluster range.
1788         */
1789        if (clusters_to_alloc || extents_to_split) {
1790                /*
1791                 * XXX: We are stretching the limits of
1792                 * ocfs2_lock_allocators(). It greatly over-estimates
1793                 * the work to be done.
1794                 */
1795                ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1796                                              wc->w_di_bh);
1797                ret = ocfs2_lock_allocators(inode, &et,
1798                                            clusters_to_alloc, extents_to_split,
1799                                            &data_ac, &meta_ac);
1800                if (ret) {
1801                        mlog_errno(ret);
1802                        goto out;
1803                }
1804
1805                if (data_ac)
1806                        data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1807
1808                credits = ocfs2_calc_extend_credits(inode->i_sb,
1809                                                    &di->id2.i_list,
1810                                                    clusters_to_alloc);
1811
1812        }
1813
1814        /*
1815         * We have to zero sparse allocated clusters, unwritten extent clusters,
1816         * and non-sparse clusters we just extended.  For non-sparse writes,
1817         * we know zeros will only be needed in the first and/or last cluster.
1818         */
1819        if (clusters_to_alloc || extents_to_split ||
1820            (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1821                            wc->w_desc[wc->w_clen - 1].c_needs_zero)))
1822                cluster_of_pages = 1;
1823        else
1824                cluster_of_pages = 0;
1825
1826        ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1827
1828        handle = ocfs2_start_trans(osb, credits);
1829        if (IS_ERR(handle)) {
1830                ret = PTR_ERR(handle);
1831                mlog_errno(ret);
1832                goto out;
1833        }
1834
1835        wc->w_handle = handle;
1836
1837        if (clusters_to_alloc) {
1838                ret = dquot_alloc_space_nodirty(inode,
1839                        ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1840                if (ret)
1841                        goto out_commit;
1842        }
1843        /*
1844         * We don't want this to fail in ocfs2_write_end(), so do it
1845         * here.
1846         */
1847        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1848                                      OCFS2_JOURNAL_ACCESS_WRITE);
1849        if (ret) {
1850                mlog_errno(ret);
1851                goto out_quota;
1852        }
1853
1854        /*
1855         * Fill our page array first. That way we've grabbed enough so
1856         * that we can zero and flush if we error after adding the
1857         * extent.
1858         */
1859        ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
1860                                         cluster_of_pages, mmap_page);
1861        if (ret && ret != -EAGAIN) {
1862                mlog_errno(ret);
1863                goto out_quota;
1864        }
1865
1866        /*
1867         * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock
1868         * the target page. In this case, we exit with no error and no target
1869         * page. This will trigger the caller, page_mkwrite(), to re-try
1870         * the operation.
1871         */
1872        if (ret == -EAGAIN) {
1873                BUG_ON(wc->w_target_page);
1874                ret = 0;
1875                goto out_quota;
1876        }
1877
1878        ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1879                                          len);
1880        if (ret) {
1881                mlog_errno(ret);
1882                goto out_quota;
1883        }
1884
1885        if (data_ac)
1886                ocfs2_free_alloc_context(data_ac);
1887        if (meta_ac)
1888                ocfs2_free_alloc_context(meta_ac);
1889
1890success:
1891        *pagep = wc->w_target_page;
1892        *fsdata = wc;
1893        return 0;
1894out_quota:
1895        if (clusters_to_alloc)
1896                dquot_free_space(inode,
1897                          ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1898out_commit:
1899        ocfs2_commit_trans(osb, handle);
1900
1901out:
1902        ocfs2_free_write_ctxt(wc);
1903
1904        if (data_ac)
1905                ocfs2_free_alloc_context(data_ac);
1906        if (meta_ac)
1907                ocfs2_free_alloc_context(meta_ac);
1908
1909        if (ret == -ENOSPC && try_free) {
1910                /*
1911                 * Try to free some truncate log so that we can have enough
1912                 * clusters to allocate.
1913                 */
1914                try_free = 0;
1915
1916                ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1917                if (ret1 == 1)
1918                        goto try_again;
1919
1920                if (ret1 < 0)
1921                        mlog_errno(ret1);
1922        }
1923
1924        return ret;
1925}
1926
1927static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1928                             loff_t pos, unsigned len, unsigned flags,
1929                             struct page **pagep, void **fsdata)
1930{
1931        int ret;
1932        struct buffer_head *di_bh = NULL;
1933        struct inode *inode = mapping->host;
1934
1935        ret = ocfs2_inode_lock(inode, &di_bh, 1);
1936        if (ret) {
1937                mlog_errno(ret);
1938                return ret;
1939        }
1940
1941        /*
1942         * Take alloc sem here to prevent concurrent lookups. That way
1943         * the mapping, zeroing and tree manipulation within
1944         * ocfs2_write() will be safe against ->readpage(). This
1945         * should also serve to lock out allocation from a shared
1946         * writeable region.
1947         */
1948        down_write(&OCFS2_I(inode)->ip_alloc_sem);
1949
1950        ret = ocfs2_write_begin_nolock(file, mapping, pos, len, flags, pagep,
1951                                       fsdata, di_bh, NULL);
1952        if (ret) {
1953                mlog_errno(ret);
1954                goto out_fail;
1955        }
1956
1957        brelse(di_bh);
1958
1959        return 0;
1960
1961out_fail:
1962        up_write(&OCFS2_I(inode)->ip_alloc_sem);
1963
1964        brelse(di_bh);
1965        ocfs2_inode_unlock(inode, 1);
1966
1967        return ret;
1968}
1969
1970static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1971                                   unsigned len, unsigned *copied,
1972                                   struct ocfs2_dinode *di,
1973                                   struct ocfs2_write_ctxt *wc)
1974{
1975        void *kaddr;
1976
1977        if (unlikely(*copied < len)) {
1978                if (!PageUptodate(wc->w_target_page)) {
1979                        *copied = 0;
1980                        return;
1981                }
1982        }
1983
1984        kaddr = kmap_atomic(wc->w_target_page);
1985        memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1986        kunmap_atomic(kaddr);
1987
1988        trace_ocfs2_write_end_inline(
1989             (unsigned long long)OCFS2_I(inode)->ip_blkno,
1990             (unsigned long long)pos, *copied,
1991             le16_to_cpu(di->id2.i_data.id_count),
1992             le16_to_cpu(di->i_dyn_features));
1993}
1994
1995int ocfs2_write_end_nolock(struct address_space *mapping,
1996                           loff_t pos, unsigned len, unsigned copied,
1997                           struct page *page, void *fsdata)
1998{
1999        int i;
2000        unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
2001        struct inode *inode = mapping->host;
2002        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2003        struct ocfs2_write_ctxt *wc = fsdata;
2004        struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
2005        handle_t *handle = wc->w_handle;
2006        struct page *tmppage;
2007
2008        if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
2009                ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
2010                goto out_write_size;
2011        }
2012
2013        if (unlikely(copied < len)) {
2014                if (!PageUptodate(wc->w_target_page))
2015                        copied = 0;
2016
2017                ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
2018                                       start+len);
2019        }
2020        flush_dcache_page(wc->w_target_page);
2021
2022        for(i = 0; i < wc->w_num_pages; i++) {
2023                tmppage = wc->w_pages[i];
2024
2025                if (tmppage == wc->w_target_page) {
2026                        from = wc->w_target_from;
2027                        to = wc->w_target_to;
2028
2029                        BUG_ON(from > PAGE_CACHE_SIZE ||
2030                               to > PAGE_CACHE_SIZE ||
2031                               to < from);
2032                } else {
2033                        /*
2034                         * Pages adjacent to the target (if any) imply
2035                         * a hole-filling write in which case we want
2036                         * to flush their entire range.
2037                         */
2038                        from = 0;
2039                        to = PAGE_CACHE_SIZE;
2040                }
2041
2042                if (page_has_buffers(tmppage)) {
2043                        if (ocfs2_should_order_data(inode))
2044                                ocfs2_jbd2_file_inode(wc->w_handle, inode);
2045                        block_commit_write(tmppage, from, to);
2046                }
2047        }
2048
2049out_write_size:
2050        pos += copied;
2051        if (pos > inode->i_size) {
2052                i_size_write(inode, pos);
2053                mark_inode_dirty(inode);
2054        }
2055        inode->i_blocks = ocfs2_inode_sector_count(inode);
2056        di->i_size = cpu_to_le64((u64)i_size_read(inode));
2057        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2058        di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
2059        di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
2060        ocfs2_journal_dirty(handle, wc->w_di_bh);
2061
2062        ocfs2_commit_trans(osb, handle);
2063
2064        ocfs2_run_deallocs(osb, &wc->w_dealloc);
2065
2066        ocfs2_free_write_ctxt(wc);
2067
2068        return copied;
2069}
2070
2071static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2072                           loff_t pos, unsigned len, unsigned copied,
2073                           struct page *page, void *fsdata)
2074{
2075        int ret;
2076        struct inode *inode = mapping->host;
2077
2078        ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
2079
2080        up_write(&OCFS2_I(inode)->ip_alloc_sem);
2081        ocfs2_inode_unlock(inode, 1);
2082
2083        return ret;
2084}
2085
2086const struct address_space_operations ocfs2_aops = {
2087        .readpage               = ocfs2_readpage,
2088        .readpages              = ocfs2_readpages,
2089        .writepage              = ocfs2_writepage,
2090        .write_begin            = ocfs2_write_begin,
2091        .write_end              = ocfs2_write_end,
2092        .bmap                   = ocfs2_bmap,
2093        .direct_IO              = ocfs2_direct_IO,
2094        .invalidatepage         = ocfs2_invalidatepage,
2095        .releasepage            = ocfs2_releasepage,
2096        .migratepage            = buffer_migrate_page,
2097        .is_partially_uptodate  = block_is_partially_uptodate,
2098        .error_remove_page      = generic_error_remove_page,
2099};
2100
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.