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, KM_USER0);
 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, KM_USER0);
 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, KM_USER0);
 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, KM_USER0);
 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		ret = AOP_TRUNCATED_PAGE;
 
 
 
 
 294		goto out_inode_unlock;
 295	}
 296
 297	/*
 298	 * i_size might have just been updated as we grabed the meta lock.  We
 299	 * might now be discovering a truncate that hit on another node.
 300	 * block_read_full_page->get_block freaks out if it is asked to read
 301	 * beyond the end of a file, so we check here.  Callers
 302	 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
 303	 * and notice that the page they just read isn't needed.
 304	 *
 305	 * XXX sys_readahead() seems to get that wrong?
 306	 */
 307	if (start >= i_size_read(inode)) {
 308		zero_user(page, 0, PAGE_SIZE);
 309		SetPageUptodate(page);
 310		ret = 0;
 311		goto out_alloc;
 312	}
 313
 314	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 315		ret = ocfs2_readpage_inline(inode, page);
 316	else
 317		ret = block_read_full_page(page, ocfs2_get_block);
 318	unlock = 0;
 319
 320out_alloc:
 321	up_read(&OCFS2_I(inode)->ip_alloc_sem);
 322out_inode_unlock:
 323	ocfs2_inode_unlock(inode, 0);
 324out:
 325	if (unlock)
 326		unlock_page(page);
 327	return ret;
 328}
 329
 330/*
 331 * This is used only for read-ahead. Failures or difficult to handle
 332 * situations are safe to ignore.
 333 *
 334 * Right now, we don't bother with BH_Boundary - in-inode extent lists
 335 * are quite large (243 extents on 4k blocks), so most inodes don't
 336 * grow out to a tree. If need be, detecting boundary extents could
 337 * trivially be added in a future version of ocfs2_get_block().
 338 */
 339static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
 340			   struct list_head *pages, unsigned nr_pages)
 341{
 342	int ret, err = -EIO;
 343	struct inode *inode = mapping->host;
 344	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 345	loff_t start;
 346	struct page *last;
 347
 348	/*
 349	 * Use the nonblocking flag for the dlm code to avoid page
 350	 * lock inversion, but don't bother with retrying.
 351	 */
 352	ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
 353	if (ret)
 354		return err;
 355
 356	if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
 357		ocfs2_inode_unlock(inode, 0);
 358		return err;
 359	}
 360
 361	/*
 362	 * Don't bother with inline-data. There isn't anything
 363	 * to read-ahead in that case anyway...
 364	 */
 365	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 366		goto out_unlock;
 367
 368	/*
 369	 * Check whether a remote node truncated this file - we just
 370	 * drop out in that case as it's not worth handling here.
 371	 */
 372	last = list_entry(pages->prev, struct page, lru);
 373	start = (loff_t)last->index << PAGE_CACHE_SHIFT;
 374	if (start >= i_size_read(inode))
 375		goto out_unlock;
 376
 377	err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
 378
 379out_unlock:
 380	up_read(&oi->ip_alloc_sem);
 381	ocfs2_inode_unlock(inode, 0);
 382
 383	return err;
 384}
 385
 386/* Note: Because we don't support holes, our allocation has
 387 * already happened (allocation writes zeros to the file data)
 388 * so we don't have to worry about ordered writes in
 389 * ocfs2_writepage.
 390 *
 391 * ->writepage is called during the process of invalidating the page cache
 392 * during blocked lock processing.  It can't block on any cluster locks
 393 * to during block mapping.  It's relying on the fact that the block
 394 * mapping can't have disappeared under the dirty pages that it is
 395 * being asked to write back.
 396 */
 397static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
 398{
 399	trace_ocfs2_writepage(
 400		(unsigned long long)OCFS2_I(page->mapping->host)->ip_blkno,
 401		page->index);
 402
 403	return block_write_full_page(page, ocfs2_get_block, wbc);
 404}
 405
 406/* Taken from ext3. We don't necessarily need the full blown
 407 * functionality yet, but IMHO it's better to cut and paste the whole
 408 * thing so we can avoid introducing our own bugs (and easily pick up
 409 * their fixes when they happen) --Mark */
 410int walk_page_buffers(	handle_t *handle,
 411			struct buffer_head *head,
 412			unsigned from,
 413			unsigned to,
 414			int *partial,
 415			int (*fn)(	handle_t *handle,
 416					struct buffer_head *bh))
 417{
 418	struct buffer_head *bh;
 419	unsigned block_start, block_end;
 420	unsigned blocksize = head->b_size;
 421	int err, ret = 0;
 422	struct buffer_head *next;
 423
 424	for (	bh = head, block_start = 0;
 425		ret == 0 && (bh != head || !block_start);
 426	    	block_start = block_end, bh = next)
 427	{
 428		next = bh->b_this_page;
 429		block_end = block_start + blocksize;
 430		if (block_end <= from || block_start >= to) {
 431			if (partial && !buffer_uptodate(bh))
 432				*partial = 1;
 433			continue;
 434		}
 435		err = (*fn)(handle, bh);
 436		if (!ret)
 437			ret = err;
 438	}
 439	return ret;
 440}
 441
 442static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
 443{
 444	sector_t status;
 445	u64 p_blkno = 0;
 446	int err = 0;
 447	struct inode *inode = mapping->host;
 448
 449	trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno,
 450			 (unsigned long long)block);
 451
 452	/* We don't need to lock journal system files, since they aren't
 453	 * accessed concurrently from multiple nodes.
 454	 */
 455	if (!INODE_JOURNAL(inode)) {
 456		err = ocfs2_inode_lock(inode, NULL, 0);
 457		if (err) {
 458			if (err != -ENOENT)
 459				mlog_errno(err);
 460			goto bail;
 461		}
 462		down_read(&OCFS2_I(inode)->ip_alloc_sem);
 463	}
 464
 465	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
 466		err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
 467						  NULL);
 468
 469	if (!INODE_JOURNAL(inode)) {
 470		up_read(&OCFS2_I(inode)->ip_alloc_sem);
 471		ocfs2_inode_unlock(inode, 0);
 472	}
 473
 474	if (err) {
 475		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
 476		     (unsigned long long)block);
 477		mlog_errno(err);
 478		goto bail;
 479	}
 480
 481bail:
 482	status = err ? 0 : p_blkno;
 483
 484	return status;
 485}
 486
 487/*
 488 * TODO: Make this into a generic get_blocks function.
 489 *
 490 * From do_direct_io in direct-io.c:
 491 *  "So what we do is to permit the ->get_blocks function to populate
 492 *   bh.b_size with the size of IO which is permitted at this offset and
 493 *   this i_blkbits."
 494 *
 495 * This function is called directly from get_more_blocks in direct-io.c.
 496 *
 497 * called like this: dio->get_blocks(dio->inode, fs_startblk,
 498 * 					fs_count, map_bh, dio->rw == WRITE);
 499 *
 500 * Note that we never bother to allocate blocks here, and thus ignore the
 501 * create argument.
 502 */
 503static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
 504				     struct buffer_head *bh_result, int create)
 505{
 506	int ret;
 507	u64 p_blkno, inode_blocks, contig_blocks;
 508	unsigned int ext_flags;
 509	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
 510	unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
 511
 512	/* This function won't even be called if the request isn't all
 513	 * nicely aligned and of the right size, so there's no need
 514	 * for us to check any of that. */
 515
 516	inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
 517
 518	/* This figures out the size of the next contiguous block, and
 519	 * our logical offset */
 520	ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
 521					  &contig_blocks, &ext_flags);
 522	if (ret) {
 523		mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
 524		     (unsigned long long)iblock);
 525		ret = -EIO;
 526		goto bail;
 527	}
 528
 529	/* We should already CoW the refcounted extent in case of create. */
 530	BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED));
 531
 532	/*
 533	 * get_more_blocks() expects us to describe a hole by clearing
 534	 * the mapped bit on bh_result().
 535	 *
 536	 * Consider an unwritten extent as a hole.
 537	 */
 538	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 539		map_bh(bh_result, inode->i_sb, p_blkno);
 540	else
 541		clear_buffer_mapped(bh_result);
 542
 543	/* make sure we don't map more than max_blocks blocks here as
 544	   that's all the kernel will handle at this point. */
 545	if (max_blocks < contig_blocks)
 546		contig_blocks = max_blocks;
 547	bh_result->b_size = contig_blocks << blocksize_bits;
 548bail:
 549	return ret;
 550}
 551
 552/*
 553 * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
 554 * particularly interested in the aio/dio case.  We use the rw_lock DLM lock
 555 * to protect io on one node from truncation on another.
 556 */
 557static void ocfs2_dio_end_io(struct kiocb *iocb,
 558			     loff_t offset,
 559			     ssize_t bytes,
 560			     void *private,
 561			     int ret,
 562			     bool is_async)
 563{
 564	struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
 565	int level;
 566
 567	/* this io's submitter should not have unlocked this before we could */
 568	BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
 569
 570	if (ocfs2_iocb_is_sem_locked(iocb))
 571		ocfs2_iocb_clear_sem_locked(iocb);
 572
 
 
 
 
 
 
 573	ocfs2_iocb_clear_rw_locked(iocb);
 574
 575	level = ocfs2_iocb_rw_locked_level(iocb);
 576	ocfs2_rw_unlock(inode, level);
 577
 578	if (is_async)
 579		aio_complete(iocb, ret, 0);
 580	inode_dio_done(inode);
 581}
 582
 583/*
 584 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
 585 * from ext3.  PageChecked() bits have been removed as OCFS2 does not
 586 * do journalled data.
 587 */
 588static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
 589{
 590	journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
 591
 592	jbd2_journal_invalidatepage(journal, page, offset);
 593}
 594
 595static int ocfs2_releasepage(struct page *page, gfp_t wait)
 596{
 597	journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
 598
 599	if (!page_has_buffers(page))
 600		return 0;
 601	return jbd2_journal_try_to_free_buffers(journal, page, wait);
 602}
 603
 604static ssize_t ocfs2_direct_IO(int rw,
 605			       struct kiocb *iocb,
 606			       const struct iovec *iov,
 607			       loff_t offset,
 608			       unsigned long nr_segs)
 609{
 610	struct file *file = iocb->ki_filp;
 611	struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
 612
 613	/*
 614	 * Fallback to buffered I/O if we see an inode without
 615	 * extents.
 616	 */
 617	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 618		return 0;
 619
 620	/* Fallback to buffered I/O if we are appending. */
 621	if (i_size_read(inode) <= offset)
 622		return 0;
 623
 624	return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
 625				    iov, offset, nr_segs,
 626				    ocfs2_direct_IO_get_blocks,
 627				    ocfs2_dio_end_io, NULL, 0);
 628}
 629
 630static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
 631					    u32 cpos,
 632					    unsigned int *start,
 633					    unsigned int *end)
 634{
 635	unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
 636
 637	if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
 638		unsigned int cpp;
 639
 640		cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
 641
 642		cluster_start = cpos % cpp;
 643		cluster_start = cluster_start << osb->s_clustersize_bits;
 644
 645		cluster_end = cluster_start + osb->s_clustersize;
 646	}
 647
 648	BUG_ON(cluster_start > PAGE_SIZE);
 649	BUG_ON(cluster_end > PAGE_SIZE);
 650
 651	if (start)
 652		*start = cluster_start;
 653	if (end)
 654		*end = cluster_end;
 655}
 656
 657/*
 658 * 'from' and 'to' are the region in the page to avoid zeroing.
 659 *
 660 * If pagesize > clustersize, this function will avoid zeroing outside
 661 * of the cluster boundary.
 662 *
 663 * from == to == 0 is code for "zero the entire cluster region"
 664 */
 665static void ocfs2_clear_page_regions(struct page *page,
 666				     struct ocfs2_super *osb, u32 cpos,
 667				     unsigned from, unsigned to)
 668{
 669	void *kaddr;
 670	unsigned int cluster_start, cluster_end;
 671
 672	ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
 673
 674	kaddr = kmap_atomic(page, KM_USER0);
 675
 676	if (from || to) {
 677		if (from > cluster_start)
 678			memset(kaddr + cluster_start, 0, from - cluster_start);
 679		if (to < cluster_end)
 680			memset(kaddr + to, 0, cluster_end - to);
 681	} else {
 682		memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
 683	}
 684
 685	kunmap_atomic(kaddr, KM_USER0);
 686}
 687
 688/*
 689 * Nonsparse file systems fully allocate before we get to the write
 690 * code. This prevents ocfs2_write() from tagging the write as an
 691 * allocating one, which means ocfs2_map_page_blocks() might try to
 692 * read-in the blocks at the tail of our file. Avoid reading them by
 693 * testing i_size against each block offset.
 694 */
 695static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
 696				 unsigned int block_start)
 697{
 698	u64 offset = page_offset(page) + block_start;
 699
 700	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
 701		return 1;
 702
 703	if (i_size_read(inode) > offset)
 704		return 1;
 705
 706	return 0;
 707}
 708
 709/*
 710 * Some of this taken from __block_write_begin(). We already have our
 711 * mapping by now though, and the entire write will be allocating or
 712 * it won't, so not much need to use BH_New.
 713 *
 714 * This will also skip zeroing, which is handled externally.
 715 */
 716int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
 717			  struct inode *inode, unsigned int from,
 718			  unsigned int to, int new)
 719{
 720	int ret = 0;
 721	struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
 722	unsigned int block_end, block_start;
 723	unsigned int bsize = 1 << inode->i_blkbits;
 724
 725	if (!page_has_buffers(page))
 726		create_empty_buffers(page, bsize, 0);
 727
 728	head = page_buffers(page);
 729	for (bh = head, block_start = 0; bh != head || !block_start;
 730	     bh = bh->b_this_page, block_start += bsize) {
 731		block_end = block_start + bsize;
 732
 733		clear_buffer_new(bh);
 734
 735		/*
 736		 * Ignore blocks outside of our i/o range -
 737		 * they may belong to unallocated clusters.
 738		 */
 739		if (block_start >= to || block_end <= from) {
 740			if (PageUptodate(page))
 741				set_buffer_uptodate(bh);
 742			continue;
 743		}
 744
 745		/*
 746		 * For an allocating write with cluster size >= page
 747		 * size, we always write the entire page.
 748		 */
 749		if (new)
 750			set_buffer_new(bh);
 751
 752		if (!buffer_mapped(bh)) {
 753			map_bh(bh, inode->i_sb, *p_blkno);
 754			unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
 755		}
 756
 757		if (PageUptodate(page)) {
 758			if (!buffer_uptodate(bh))
 759				set_buffer_uptodate(bh);
 760		} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
 761			   !buffer_new(bh) &&
 762			   ocfs2_should_read_blk(inode, page, block_start) &&
 763			   (block_start < from || block_end > to)) {
 764			ll_rw_block(READ, 1, &bh);
 765			*wait_bh++=bh;
 766		}
 767
 768		*p_blkno = *p_blkno + 1;
 769	}
 770
 771	/*
 772	 * If we issued read requests - let them complete.
 773	 */
 774	while(wait_bh > wait) {
 775		wait_on_buffer(*--wait_bh);
 776		if (!buffer_uptodate(*wait_bh))
 777			ret = -EIO;
 778	}
 779
 780	if (ret == 0 || !new)
 781		return ret;
 782
 783	/*
 784	 * If we get -EIO above, zero out any newly allocated blocks
 785	 * to avoid exposing stale data.
 786	 */
 787	bh = head;
 788	block_start = 0;
 789	do {
 790		block_end = block_start + bsize;
 791		if (block_end <= from)
 792			goto next_bh;
 793		if (block_start >= to)
 794			break;
 795
 796		zero_user(page, block_start, bh->b_size);
 797		set_buffer_uptodate(bh);
 798		mark_buffer_dirty(bh);
 799
 800next_bh:
 801		block_start = block_end;
 802		bh = bh->b_this_page;
 803	} while (bh != head);
 804
 805	return ret;
 806}
 807
 808#if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
 809#define OCFS2_MAX_CTXT_PAGES	1
 810#else
 811#define OCFS2_MAX_CTXT_PAGES	(OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
 812#endif
 813
 814#define OCFS2_MAX_CLUSTERS_PER_PAGE	(PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
 815
 816/*
 817 * Describe the state of a single cluster to be written to.
 818 */
 819struct ocfs2_write_cluster_desc {
 820	u32		c_cpos;
 821	u32		c_phys;
 822	/*
 823	 * Give this a unique field because c_phys eventually gets
 824	 * filled.
 825	 */
 826	unsigned	c_new;
 827	unsigned	c_unwritten;
 828	unsigned	c_needs_zero;
 829};
 830
 831struct ocfs2_write_ctxt {
 832	/* Logical cluster position / len of write */
 833	u32				w_cpos;
 834	u32				w_clen;
 835
 836	/* First cluster allocated in a nonsparse extend */
 837	u32				w_first_new_cpos;
 838
 839	struct ocfs2_write_cluster_desc	w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
 840
 841	/*
 842	 * This is true if page_size > cluster_size.
 843	 *
 844	 * It triggers a set of special cases during write which might
 845	 * have to deal with allocating writes to partial pages.
 846	 */
 847	unsigned int			w_large_pages;
 848
 849	/*
 850	 * Pages involved in this write.
 851	 *
 852	 * w_target_page is the page being written to by the user.
 853	 *
 854	 * w_pages is an array of pages which always contains
 855	 * w_target_page, and in the case of an allocating write with
 856	 * page_size < cluster size, it will contain zero'd and mapped
 857	 * pages adjacent to w_target_page which need to be written
 858	 * out in so that future reads from that region will get
 859	 * zero's.
 860	 */
 861	unsigned int			w_num_pages;
 862	struct page			*w_pages[OCFS2_MAX_CTXT_PAGES];
 863	struct page			*w_target_page;
 864
 865	/*
 
 
 
 
 
 
 866	 * ocfs2_write_end() uses this to know what the real range to
 867	 * write in the target should be.
 868	 */
 869	unsigned int			w_target_from;
 870	unsigned int			w_target_to;
 871
 872	/*
 873	 * We could use journal_current_handle() but this is cleaner,
 874	 * IMHO -Mark
 875	 */
 876	handle_t			*w_handle;
 877
 878	struct buffer_head		*w_di_bh;
 879
 880	struct ocfs2_cached_dealloc_ctxt w_dealloc;
 881};
 882
 883void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
 884{
 885	int i;
 886
 887	for(i = 0; i < num_pages; i++) {
 888		if (pages[i]) {
 889			unlock_page(pages[i]);
 890			mark_page_accessed(pages[i]);
 891			page_cache_release(pages[i]);
 892		}
 893	}
 894}
 895
 896static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
 897{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 898	ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
 899
 900	brelse(wc->w_di_bh);
 901	kfree(wc);
 902}
 903
 904static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
 905				  struct ocfs2_super *osb, loff_t pos,
 906				  unsigned len, struct buffer_head *di_bh)
 907{
 908	u32 cend;
 909	struct ocfs2_write_ctxt *wc;
 910
 911	wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
 912	if (!wc)
 913		return -ENOMEM;
 914
 915	wc->w_cpos = pos >> osb->s_clustersize_bits;
 916	wc->w_first_new_cpos = UINT_MAX;
 917	cend = (pos + len - 1) >> osb->s_clustersize_bits;
 918	wc->w_clen = cend - wc->w_cpos + 1;
 919	get_bh(di_bh);
 920	wc->w_di_bh = di_bh;
 921
 922	if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
 923		wc->w_large_pages = 1;
 924	else
 925		wc->w_large_pages = 0;
 926
 927	ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
 928
 929	*wcp = wc;
 930
 931	return 0;
 932}
 933
 934/*
 935 * If a page has any new buffers, zero them out here, and mark them uptodate
 936 * and dirty so they'll be written out (in order to prevent uninitialised
 937 * block data from leaking). And clear the new bit.
 938 */
 939static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
 940{
 941	unsigned int block_start, block_end;
 942	struct buffer_head *head, *bh;
 943
 944	BUG_ON(!PageLocked(page));
 945	if (!page_has_buffers(page))
 946		return;
 947
 948	bh = head = page_buffers(page);
 949	block_start = 0;
 950	do {
 951		block_end = block_start + bh->b_size;
 952
 953		if (buffer_new(bh)) {
 954			if (block_end > from && block_start < to) {
 955				if (!PageUptodate(page)) {
 956					unsigned start, end;
 957
 958					start = max(from, block_start);
 959					end = min(to, block_end);
 960
 961					zero_user_segment(page, start, end);
 962					set_buffer_uptodate(bh);
 963				}
 964
 965				clear_buffer_new(bh);
 966				mark_buffer_dirty(bh);
 967			}
 968		}
 969
 970		block_start = block_end;
 971		bh = bh->b_this_page;
 972	} while (bh != head);
 973}
 974
 975/*
 976 * Only called when we have a failure during allocating write to write
 977 * zero's to the newly allocated region.
 978 */
 979static void ocfs2_write_failure(struct inode *inode,
 980				struct ocfs2_write_ctxt *wc,
 981				loff_t user_pos, unsigned user_len)
 982{
 983	int i;
 984	unsigned from = user_pos & (PAGE_CACHE_SIZE - 1),
 985		to = user_pos + user_len;
 986	struct page *tmppage;
 987
 988	ocfs2_zero_new_buffers(wc->w_target_page, from, to);
 989
 990	for(i = 0; i < wc->w_num_pages; i++) {
 991		tmppage = wc->w_pages[i];
 992
 993		if (page_has_buffers(tmppage)) {
 994			if (ocfs2_should_order_data(inode))
 995				ocfs2_jbd2_file_inode(wc->w_handle, inode);
 996
 997			block_commit_write(tmppage, from, to);
 998		}
 999	}
1000}
1001
1002static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
1003					struct ocfs2_write_ctxt *wc,
1004					struct page *page, u32 cpos,
1005					loff_t user_pos, unsigned user_len,
1006					int new)
1007{
1008	int ret;
1009	unsigned int map_from = 0, map_to = 0;
1010	unsigned int cluster_start, cluster_end;
1011	unsigned int user_data_from = 0, user_data_to = 0;
1012
1013	ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
1014					&cluster_start, &cluster_end);
1015
1016	/* treat the write as new if the a hole/lseek spanned across
1017	 * the page boundary.
1018	 */
1019	new = new | ((i_size_read(inode) <= page_offset(page)) &&
1020			(page_offset(page) <= user_pos));
1021
1022	if (page == wc->w_target_page) {
1023		map_from = user_pos & (PAGE_CACHE_SIZE - 1);
1024		map_to = map_from + user_len;
1025
1026		if (new)
1027			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1028						    cluster_start, cluster_end,
1029						    new);
1030		else
1031			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1032						    map_from, map_to, new);
1033		if (ret) {
1034			mlog_errno(ret);
1035			goto out;
1036		}
1037
1038		user_data_from = map_from;
1039		user_data_to = map_to;
1040		if (new) {
1041			map_from = cluster_start;
1042			map_to = cluster_end;
1043		}
1044	} else {
1045		/*
1046		 * If we haven't allocated the new page yet, we
1047		 * shouldn't be writing it out without copying user
1048		 * data. This is likely a math error from the caller.
1049		 */
1050		BUG_ON(!new);
1051
1052		map_from = cluster_start;
1053		map_to = cluster_end;
1054
1055		ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1056					    cluster_start, cluster_end, new);
1057		if (ret) {
1058			mlog_errno(ret);
1059			goto out;
1060		}
1061	}
1062
1063	/*
1064	 * Parts of newly allocated pages need to be zero'd.
1065	 *
1066	 * Above, we have also rewritten 'to' and 'from' - as far as
1067	 * the rest of the function is concerned, the entire cluster
1068	 * range inside of a page needs to be written.
1069	 *
1070	 * We can skip this if the page is up to date - it's already
1071	 * been zero'd from being read in as a hole.
1072	 */
1073	if (new && !PageUptodate(page))
1074		ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1075					 cpos, user_data_from, user_data_to);
1076
1077	flush_dcache_page(page);
1078
1079out:
1080	return ret;
1081}
1082
1083/*
1084 * This function will only grab one clusters worth of pages.
1085 */
1086static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1087				      struct ocfs2_write_ctxt *wc,
1088				      u32 cpos, loff_t user_pos,
1089				      unsigned user_len, int new,
1090				      struct page *mmap_page)
1091{
1092	int ret = 0, i;
1093	unsigned long start, target_index, end_index, index;
1094	struct inode *inode = mapping->host;
1095	loff_t last_byte;
1096
1097	target_index = user_pos >> PAGE_CACHE_SHIFT;
1098
1099	/*
1100	 * Figure out how many pages we'll be manipulating here. For
1101	 * non allocating write, we just change the one
1102	 * page. Otherwise, we'll need a whole clusters worth.  If we're
1103	 * writing past i_size, we only need enough pages to cover the
1104	 * last page of the write.
1105	 */
1106	if (new) {
1107		wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1108		start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1109		/*
1110		 * We need the index *past* the last page we could possibly
1111		 * touch.  This is the page past the end of the write or
1112		 * i_size, whichever is greater.
1113		 */
1114		last_byte = max(user_pos + user_len, i_size_read(inode));
1115		BUG_ON(last_byte < 1);
1116		end_index = ((last_byte - 1) >> PAGE_CACHE_SHIFT) + 1;
1117		if ((start + wc->w_num_pages) > end_index)
1118			wc->w_num_pages = end_index - start;
1119	} else {
1120		wc->w_num_pages = 1;
1121		start = target_index;
1122	}
1123
1124	for(i = 0; i < wc->w_num_pages; i++) {
1125		index = start + i;
1126
1127		if (index == target_index && mmap_page) {
1128			/*
1129			 * ocfs2_pagemkwrite() is a little different
1130			 * and wants us to directly use the page
1131			 * passed in.
1132			 */
1133			lock_page(mmap_page);
1134
 
1135			if (mmap_page->mapping != mapping) {
 
1136				unlock_page(mmap_page);
1137				/*
1138				 * Sanity check - the locking in
1139				 * ocfs2_pagemkwrite() should ensure
1140				 * that this code doesn't trigger.
1141				 */
1142				ret = -EINVAL;
1143				mlog_errno(ret);
1144				goto out;
1145			}
1146
1147			page_cache_get(mmap_page);
1148			wc->w_pages[i] = mmap_page;
 
1149		} else {
1150			wc->w_pages[i] = find_or_create_page(mapping, index,
1151							     GFP_NOFS);
1152			if (!wc->w_pages[i]) {
1153				ret = -ENOMEM;
1154				mlog_errno(ret);
1155				goto out;
1156			}
1157		}
 
1158
1159		if (index == target_index)
1160			wc->w_target_page = wc->w_pages[i];
1161	}
1162out:
 
 
1163	return ret;
1164}
1165
1166/*
1167 * Prepare a single cluster for write one cluster into the file.
1168 */
1169static int ocfs2_write_cluster(struct address_space *mapping,
1170			       u32 phys, unsigned int unwritten,
1171			       unsigned int should_zero,
1172			       struct ocfs2_alloc_context *data_ac,
1173			       struct ocfs2_alloc_context *meta_ac,
1174			       struct ocfs2_write_ctxt *wc, u32 cpos,
1175			       loff_t user_pos, unsigned user_len)
1176{
1177	int ret, i, new;
1178	u64 v_blkno, p_blkno;
1179	struct inode *inode = mapping->host;
1180	struct ocfs2_extent_tree et;
1181
1182	new = phys == 0 ? 1 : 0;
1183	if (new) {
1184		u32 tmp_pos;
1185
1186		/*
1187		 * This is safe to call with the page locks - it won't take
1188		 * any additional semaphores or cluster locks.
1189		 */
1190		tmp_pos = cpos;
1191		ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1192					   &tmp_pos, 1, 0, wc->w_di_bh,
1193					   wc->w_handle, data_ac,
1194					   meta_ac, NULL);
1195		/*
1196		 * This shouldn't happen because we must have already
1197		 * calculated the correct meta data allocation required. The
1198		 * internal tree allocation code should know how to increase
1199		 * transaction credits itself.
1200		 *
1201		 * If need be, we could handle -EAGAIN for a
1202		 * RESTART_TRANS here.
1203		 */
1204		mlog_bug_on_msg(ret == -EAGAIN,
1205				"Inode %llu: EAGAIN return during allocation.\n",
1206				(unsigned long long)OCFS2_I(inode)->ip_blkno);
1207		if (ret < 0) {
1208			mlog_errno(ret);
1209			goto out;
1210		}
1211	} else if (unwritten) {
1212		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1213					      wc->w_di_bh);
1214		ret = ocfs2_mark_extent_written(inode, &et,
1215						wc->w_handle, cpos, 1, phys,
1216						meta_ac, &wc->w_dealloc);
1217		if (ret < 0) {
1218			mlog_errno(ret);
1219			goto out;
1220		}
1221	}
1222
1223	if (should_zero)
1224		v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
1225	else
1226		v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
1227
1228	/*
1229	 * The only reason this should fail is due to an inability to
1230	 * find the extent added.
1231	 */
1232	ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
1233					  NULL);
1234	if (ret < 0) {
1235		ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
1236			    "at logical block %llu",
1237			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
1238			    (unsigned long long)v_blkno);
1239		goto out;
1240	}
1241
1242	BUG_ON(p_blkno == 0);
1243
1244	for(i = 0; i < wc->w_num_pages; i++) {
1245		int tmpret;
1246
1247		tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1248						      wc->w_pages[i], cpos,
1249						      user_pos, user_len,
1250						      should_zero);
1251		if (tmpret) {
1252			mlog_errno(tmpret);
1253			if (ret == 0)
1254				ret = tmpret;
1255		}
1256	}
1257
1258	/*
1259	 * We only have cleanup to do in case of allocating write.
1260	 */
1261	if (ret && new)
1262		ocfs2_write_failure(inode, wc, user_pos, user_len);
1263
1264out:
1265
1266	return ret;
1267}
1268
1269static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1270				       struct ocfs2_alloc_context *data_ac,
1271				       struct ocfs2_alloc_context *meta_ac,
1272				       struct ocfs2_write_ctxt *wc,
1273				       loff_t pos, unsigned len)
1274{
1275	int ret, i;
1276	loff_t cluster_off;
1277	unsigned int local_len = len;
1278	struct ocfs2_write_cluster_desc *desc;
1279	struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1280
1281	for (i = 0; i < wc->w_clen; i++) {
1282		desc = &wc->w_desc[i];
1283
1284		/*
1285		 * We have to make sure that the total write passed in
1286		 * doesn't extend past a single cluster.
1287		 */
1288		local_len = len;
1289		cluster_off = pos & (osb->s_clustersize - 1);
1290		if ((cluster_off + local_len) > osb->s_clustersize)
1291			local_len = osb->s_clustersize - cluster_off;
1292
1293		ret = ocfs2_write_cluster(mapping, desc->c_phys,
1294					  desc->c_unwritten,
1295					  desc->c_needs_zero,
1296					  data_ac, meta_ac,
1297					  wc, desc->c_cpos, pos, local_len);
1298		if (ret) {
1299			mlog_errno(ret);
1300			goto out;
1301		}
1302
1303		len -= local_len;
1304		pos += local_len;
1305	}
1306
1307	ret = 0;
1308out:
1309	return ret;
1310}
1311
1312/*
1313 * ocfs2_write_end() wants to know which parts of the target page it
1314 * should complete the write on. It's easiest to compute them ahead of
1315 * time when a more complete view of the write is available.
1316 */
1317static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1318					struct ocfs2_write_ctxt *wc,
1319					loff_t pos, unsigned len, int alloc)
1320{
1321	struct ocfs2_write_cluster_desc *desc;
1322
1323	wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
1324	wc->w_target_to = wc->w_target_from + len;
1325
1326	if (alloc == 0)
1327		return;
1328
1329	/*
1330	 * Allocating write - we may have different boundaries based
1331	 * on page size and cluster size.
1332	 *
1333	 * NOTE: We can no longer compute one value from the other as
1334	 * the actual write length and user provided length may be
1335	 * different.
1336	 */
1337
1338	if (wc->w_large_pages) {
1339		/*
1340		 * We only care about the 1st and last cluster within
1341		 * our range and whether they should be zero'd or not. Either
1342		 * value may be extended out to the start/end of a
1343		 * newly allocated cluster.
1344		 */
1345		desc = &wc->w_desc[0];
1346		if (desc->c_needs_zero)
1347			ocfs2_figure_cluster_boundaries(osb,
1348							desc->c_cpos,
1349							&wc->w_target_from,
1350							NULL);
1351
1352		desc = &wc->w_desc[wc->w_clen - 1];
1353		if (desc->c_needs_zero)
1354			ocfs2_figure_cluster_boundaries(osb,
1355							desc->c_cpos,
1356							NULL,
1357							&wc->w_target_to);
1358	} else {
1359		wc->w_target_from = 0;
1360		wc->w_target_to = PAGE_CACHE_SIZE;
1361	}
1362}
1363
1364/*
1365 * Populate each single-cluster write descriptor in the write context
1366 * with information about the i/o to be done.
1367 *
1368 * Returns the number of clusters that will have to be allocated, as
1369 * well as a worst case estimate of the number of extent records that
1370 * would have to be created during a write to an unwritten region.
1371 */
1372static int ocfs2_populate_write_desc(struct inode *inode,
1373				     struct ocfs2_write_ctxt *wc,
1374				     unsigned int *clusters_to_alloc,
1375				     unsigned int *extents_to_split)
1376{
1377	int ret;
1378	struct ocfs2_write_cluster_desc *desc;
1379	unsigned int num_clusters = 0;
1380	unsigned int ext_flags = 0;
1381	u32 phys = 0;
1382	int i;
1383
1384	*clusters_to_alloc = 0;
1385	*extents_to_split = 0;
1386
1387	for (i = 0; i < wc->w_clen; i++) {
1388		desc = &wc->w_desc[i];
1389		desc->c_cpos = wc->w_cpos + i;
1390
1391		if (num_clusters == 0) {
1392			/*
1393			 * Need to look up the next extent record.
1394			 */
1395			ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1396						 &num_clusters, &ext_flags);
1397			if (ret) {
1398				mlog_errno(ret);
1399				goto out;
1400			}
1401
1402			/* We should already CoW the refcountd extent. */
1403			BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1404
1405			/*
1406			 * Assume worst case - that we're writing in
1407			 * the middle of the extent.
1408			 *
1409			 * We can assume that the write proceeds from
1410			 * left to right, in which case the extent
1411			 * insert code is smart enough to coalesce the
1412			 * next splits into the previous records created.
1413			 */
1414			if (ext_flags & OCFS2_EXT_UNWRITTEN)
1415				*extents_to_split = *extents_to_split + 2;
1416		} else if (phys) {
1417			/*
1418			 * Only increment phys if it doesn't describe
1419			 * a hole.
1420			 */
1421			phys++;
1422		}
1423
1424		/*
1425		 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1426		 * file that got extended.  w_first_new_cpos tells us
1427		 * where the newly allocated clusters are so we can
1428		 * zero them.
1429		 */
1430		if (desc->c_cpos >= wc->w_first_new_cpos) {
1431			BUG_ON(phys == 0);
1432			desc->c_needs_zero = 1;
1433		}
1434
1435		desc->c_phys = phys;
1436		if (phys == 0) {
1437			desc->c_new = 1;
1438			desc->c_needs_zero = 1;
1439			*clusters_to_alloc = *clusters_to_alloc + 1;
1440		}
1441
1442		if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1443			desc->c_unwritten = 1;
1444			desc->c_needs_zero = 1;
1445		}
1446
1447		num_clusters--;
1448	}
1449
1450	ret = 0;
1451out:
1452	return ret;
1453}
1454
1455static int ocfs2_write_begin_inline(struct address_space *mapping,
1456				    struct inode *inode,
1457				    struct ocfs2_write_ctxt *wc)
1458{
1459	int ret;
1460	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1461	struct page *page;
1462	handle_t *handle;
1463	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1464
1465	page = find_or_create_page(mapping, 0, GFP_NOFS);
1466	if (!page) {
1467		ret = -ENOMEM;
1468		mlog_errno(ret);
1469		goto out;
1470	}
1471	/*
1472	 * If we don't set w_num_pages then this page won't get unlocked
1473	 * and freed on cleanup of the write context.
1474	 */
1475	wc->w_pages[0] = wc->w_target_page = page;
1476	wc->w_num_pages = 1;
1477
1478	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1479	if (IS_ERR(handle)) {
1480		ret = PTR_ERR(handle);
1481		mlog_errno(ret);
1482		goto out;
1483	}
1484
1485	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1486				      OCFS2_JOURNAL_ACCESS_WRITE);
1487	if (ret) {
1488		ocfs2_commit_trans(osb, handle);
1489
1490		mlog_errno(ret);
1491		goto out;
1492	}
1493
1494	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1495		ocfs2_set_inode_data_inline(inode, di);
1496
1497	if (!PageUptodate(page)) {
1498		ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1499		if (ret) {
1500			ocfs2_commit_trans(osb, handle);
1501
1502			goto out;
1503		}
1504	}
1505
1506	wc->w_handle = handle;
1507out:
1508	return ret;
1509}
1510
1511int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1512{
1513	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1514
1515	if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1516		return 1;
1517	return 0;
1518}
1519
1520static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1521					  struct inode *inode, loff_t pos,
1522					  unsigned len, struct page *mmap_page,
1523					  struct ocfs2_write_ctxt *wc)
1524{
1525	int ret, written = 0;
1526	loff_t end = pos + len;
1527	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1528	struct ocfs2_dinode *di = NULL;
1529
1530	trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1531					     len, (unsigned long long)pos,
1532					     oi->ip_dyn_features);
1533
1534	/*
1535	 * Handle inodes which already have inline data 1st.
1536	 */
1537	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1538		if (mmap_page == NULL &&
1539		    ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1540			goto do_inline_write;
1541
1542		/*
1543		 * The write won't fit - we have to give this inode an
1544		 * inline extent list now.
1545		 */
1546		ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1547		if (ret)
1548			mlog_errno(ret);
1549		goto out;
1550	}
1551
1552	/*
1553	 * Check whether the inode can accept inline data.
1554	 */
1555	if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1556		return 0;
1557
1558	/*
1559	 * Check whether the write can fit.
1560	 */
1561	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1562	if (mmap_page ||
1563	    end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1564		return 0;
1565
1566do_inline_write:
1567	ret = ocfs2_write_begin_inline(mapping, inode, wc);
1568	if (ret) {
1569		mlog_errno(ret);
1570		goto out;
1571	}
1572
1573	/*
1574	 * This signals to the caller that the data can be written
1575	 * inline.
1576	 */
1577	written = 1;
1578out:
1579	return written ? written : ret;
1580}
1581
1582/*
1583 * This function only does anything for file systems which can't
1584 * handle sparse files.
1585 *
1586 * What we want to do here is fill in any hole between the current end
1587 * of allocation and the end of our write. That way the rest of the
1588 * write path can treat it as an non-allocating write, which has no
1589 * special case code for sparse/nonsparse files.
1590 */
1591static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1592					struct buffer_head *di_bh,
1593					loff_t pos, unsigned len,
1594					struct ocfs2_write_ctxt *wc)
1595{
1596	int ret;
1597	loff_t newsize = pos + len;
1598
1599	BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1600
1601	if (newsize <= i_size_read(inode))
1602		return 0;
1603
1604	ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1605	if (ret)
1606		mlog_errno(ret);
1607
1608	wc->w_first_new_cpos =
1609		ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1610
1611	return ret;
1612}
1613
1614static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1615			   loff_t pos)
1616{
1617	int ret = 0;
1618
1619	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1620	if (pos > i_size_read(inode))
1621		ret = ocfs2_zero_extend(inode, di_bh, pos);
1622
1623	return ret;
1624}
1625
1626/*
1627 * Try to flush truncate logs if we can free enough clusters from it.
1628 * As for return value, "< 0" means error, "0" no space and "1" means
1629 * we have freed enough spaces and let the caller try to allocate again.
1630 */
1631static int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb,
1632					  unsigned int needed)
1633{
1634	tid_t target;
1635	int ret = 0;
1636	unsigned int truncated_clusters;
1637
1638	mutex_lock(&osb->osb_tl_inode->i_mutex);
1639	truncated_clusters = osb->truncated_clusters;
1640	mutex_unlock(&osb->osb_tl_inode->i_mutex);
1641
1642	/*
1643	 * Check whether we can succeed in allocating if we free
1644	 * the truncate log.
1645	 */
1646	if (truncated_clusters < needed)
1647		goto out;
1648
1649	ret = ocfs2_flush_truncate_log(osb);
1650	if (ret) {
1651		mlog_errno(ret);
1652		goto out;
1653	}
1654
1655	if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) {
1656		jbd2_log_wait_commit(osb->journal->j_journal, target);
1657		ret = 1;
1658	}
1659out:
1660	return ret;
1661}
1662
1663int ocfs2_write_begin_nolock(struct file *filp,
1664			     struct address_space *mapping,
1665			     loff_t pos, unsigned len, unsigned flags,
1666			     struct page **pagep, void **fsdata,
1667			     struct buffer_head *di_bh, struct page *mmap_page)
1668{
1669	int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1670	unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1671	struct ocfs2_write_ctxt *wc;
1672	struct inode *inode = mapping->host;
1673	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1674	struct ocfs2_dinode *di;
1675	struct ocfs2_alloc_context *data_ac = NULL;
1676	struct ocfs2_alloc_context *meta_ac = NULL;
1677	handle_t *handle;
1678	struct ocfs2_extent_tree et;
1679	int try_free = 1, ret1;
1680
1681try_again:
1682	ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
1683	if (ret) {
1684		mlog_errno(ret);
1685		return ret;
1686	}
1687
1688	if (ocfs2_supports_inline_data(osb)) {
1689		ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1690						     mmap_page, wc);
1691		if (ret == 1) {
1692			ret = 0;
1693			goto success;
1694		}
1695		if (ret < 0) {
1696			mlog_errno(ret);
1697			goto out;
1698		}
1699	}
1700
1701	if (ocfs2_sparse_alloc(osb))
1702		ret = ocfs2_zero_tail(inode, di_bh, pos);
1703	else
1704		ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos, len,
1705						   wc);
1706	if (ret) {
1707		mlog_errno(ret);
1708		goto out;
1709	}
1710
1711	ret = ocfs2_check_range_for_refcount(inode, pos, len);
1712	if (ret < 0) {
1713		mlog_errno(ret);
1714		goto out;
1715	} else if (ret == 1) {
1716		clusters_need = wc->w_clen;
1717		ret = ocfs2_refcount_cow(inode, filp, di_bh,
1718					 wc->w_cpos, wc->w_clen, UINT_MAX);
1719		if (ret) {
1720			mlog_errno(ret);
1721			goto out;
1722		}
1723	}
1724
1725	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1726					&extents_to_split);
1727	if (ret) {
1728		mlog_errno(ret);
1729		goto out;
1730	}
1731	clusters_need += clusters_to_alloc;
1732
1733	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1734
1735	trace_ocfs2_write_begin_nolock(
1736			(unsigned long long)OCFS2_I(inode)->ip_blkno,
1737			(long long)i_size_read(inode),
1738			le32_to_cpu(di->i_clusters),
1739			pos, len, flags, mmap_page,
1740			clusters_to_alloc, extents_to_split);
1741
1742	/*
1743	 * We set w_target_from, w_target_to here so that
1744	 * ocfs2_write_end() knows which range in the target page to
1745	 * write out. An allocation requires that we write the entire
1746	 * cluster range.
1747	 */
1748	if (clusters_to_alloc || extents_to_split) {
1749		/*
1750		 * XXX: We are stretching the limits of
1751		 * ocfs2_lock_allocators(). It greatly over-estimates
1752		 * the work to be done.
1753		 */
1754		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1755					      wc->w_di_bh);
1756		ret = ocfs2_lock_allocators(inode, &et,
1757					    clusters_to_alloc, extents_to_split,
1758					    &data_ac, &meta_ac);
1759		if (ret) {
1760			mlog_errno(ret);
1761			goto out;
1762		}
1763
1764		if (data_ac)
1765			data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1766
1767		credits = ocfs2_calc_extend_credits(inode->i_sb,
1768						    &di->id2.i_list,
1769						    clusters_to_alloc);
1770
1771	}
1772
1773	/*
1774	 * We have to zero sparse allocated clusters, unwritten extent clusters,
1775	 * and non-sparse clusters we just extended.  For non-sparse writes,
1776	 * we know zeros will only be needed in the first and/or last cluster.
1777	 */
1778	if (clusters_to_alloc || extents_to_split ||
1779	    (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1780			    wc->w_desc[wc->w_clen - 1].c_needs_zero)))
1781		cluster_of_pages = 1;
1782	else
1783		cluster_of_pages = 0;
1784
1785	ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1786
1787	handle = ocfs2_start_trans(osb, credits);
1788	if (IS_ERR(handle)) {
1789		ret = PTR_ERR(handle);
1790		mlog_errno(ret);
1791		goto out;
1792	}
1793
1794	wc->w_handle = handle;
1795
1796	if (clusters_to_alloc) {
1797		ret = dquot_alloc_space_nodirty(inode,
1798			ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1799		if (ret)
1800			goto out_commit;
1801	}
1802	/*
1803	 * We don't want this to fail in ocfs2_write_end(), so do it
1804	 * here.
1805	 */
1806	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1807				      OCFS2_JOURNAL_ACCESS_WRITE);
1808	if (ret) {
1809		mlog_errno(ret);
1810		goto out_quota;
1811	}
1812
1813	/*
1814	 * Fill our page array first. That way we've grabbed enough so
1815	 * that we can zero and flush if we error after adding the
1816	 * extent.
1817	 */
1818	ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
1819					 cluster_of_pages, mmap_page);
1820	if (ret) {
1821		mlog_errno(ret);
1822		goto out_quota;
1823	}
1824
 
 
 
 
 
 
 
 
 
 
 
 
1825	ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1826					  len);
1827	if (ret) {
1828		mlog_errno(ret);
1829		goto out_quota;
1830	}
1831
1832	if (data_ac)
1833		ocfs2_free_alloc_context(data_ac);
1834	if (meta_ac)
1835		ocfs2_free_alloc_context(meta_ac);
1836
1837success:
1838	*pagep = wc->w_target_page;
1839	*fsdata = wc;
1840	return 0;
1841out_quota:
1842	if (clusters_to_alloc)
1843		dquot_free_space(inode,
1844			  ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1845out_commit:
1846	ocfs2_commit_trans(osb, handle);
1847
1848out:
1849	ocfs2_free_write_ctxt(wc);
1850
1851	if (data_ac)
1852		ocfs2_free_alloc_context(data_ac);
1853	if (meta_ac)
 
 
1854		ocfs2_free_alloc_context(meta_ac);
 
 
1855
1856	if (ret == -ENOSPC && try_free) {
1857		/*
1858		 * Try to free some truncate log so that we can have enough
1859		 * clusters to allocate.
1860		 */
1861		try_free = 0;
1862
1863		ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1864		if (ret1 == 1)
1865			goto try_again;
1866
1867		if (ret1 < 0)
1868			mlog_errno(ret1);
1869	}
1870
1871	return ret;
1872}
1873
1874static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1875			     loff_t pos, unsigned len, unsigned flags,
1876			     struct page **pagep, void **fsdata)
1877{
1878	int ret;
1879	struct buffer_head *di_bh = NULL;
1880	struct inode *inode = mapping->host;
1881
1882	ret = ocfs2_inode_lock(inode, &di_bh, 1);
1883	if (ret) {
1884		mlog_errno(ret);
1885		return ret;
1886	}
1887
1888	/*
1889	 * Take alloc sem here to prevent concurrent lookups. That way
1890	 * the mapping, zeroing and tree manipulation within
1891	 * ocfs2_write() will be safe against ->readpage(). This
1892	 * should also serve to lock out allocation from a shared
1893	 * writeable region.
1894	 */
1895	down_write(&OCFS2_I(inode)->ip_alloc_sem);
1896
1897	ret = ocfs2_write_begin_nolock(file, mapping, pos, len, flags, pagep,
1898				       fsdata, di_bh, NULL);
1899	if (ret) {
1900		mlog_errno(ret);
1901		goto out_fail;
1902	}
1903
1904	brelse(di_bh);
1905
1906	return 0;
1907
1908out_fail:
1909	up_write(&OCFS2_I(inode)->ip_alloc_sem);
1910
1911	brelse(di_bh);
1912	ocfs2_inode_unlock(inode, 1);
1913
1914	return ret;
1915}
1916
1917static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1918				   unsigned len, unsigned *copied,
1919				   struct ocfs2_dinode *di,
1920				   struct ocfs2_write_ctxt *wc)
1921{
1922	void *kaddr;
1923
1924	if (unlikely(*copied < len)) {
1925		if (!PageUptodate(wc->w_target_page)) {
1926			*copied = 0;
1927			return;
1928		}
1929	}
1930
1931	kaddr = kmap_atomic(wc->w_target_page, KM_USER0);
1932	memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1933	kunmap_atomic(kaddr, KM_USER0);
1934
1935	trace_ocfs2_write_end_inline(
1936	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1937	     (unsigned long long)pos, *copied,
1938	     le16_to_cpu(di->id2.i_data.id_count),
1939	     le16_to_cpu(di->i_dyn_features));
1940}
1941
1942int ocfs2_write_end_nolock(struct address_space *mapping,
1943			   loff_t pos, unsigned len, unsigned copied,
1944			   struct page *page, void *fsdata)
1945{
1946	int i;
1947	unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
1948	struct inode *inode = mapping->host;
1949	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1950	struct ocfs2_write_ctxt *wc = fsdata;
1951	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1952	handle_t *handle = wc->w_handle;
1953	struct page *tmppage;
1954
1955	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1956		ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1957		goto out_write_size;
1958	}
1959
1960	if (unlikely(copied < len)) {
1961		if (!PageUptodate(wc->w_target_page))
1962			copied = 0;
1963
1964		ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1965				       start+len);
1966	}
1967	flush_dcache_page(wc->w_target_page);
1968
1969	for(i = 0; i < wc->w_num_pages; i++) {
1970		tmppage = wc->w_pages[i];
1971
1972		if (tmppage == wc->w_target_page) {
1973			from = wc->w_target_from;
1974			to = wc->w_target_to;
1975
1976			BUG_ON(from > PAGE_CACHE_SIZE ||
1977			       to > PAGE_CACHE_SIZE ||
1978			       to < from);
1979		} else {
1980			/*
1981			 * Pages adjacent to the target (if any) imply
1982			 * a hole-filling write in which case we want
1983			 * to flush their entire range.
1984			 */
1985			from = 0;
1986			to = PAGE_CACHE_SIZE;
1987		}
1988
1989		if (page_has_buffers(tmppage)) {
1990			if (ocfs2_should_order_data(inode))
1991				ocfs2_jbd2_file_inode(wc->w_handle, inode);
1992			block_commit_write(tmppage, from, to);
1993		}
1994	}
1995
1996out_write_size:
1997	pos += copied;
1998	if (pos > inode->i_size) {
1999		i_size_write(inode, pos);
2000		mark_inode_dirty(inode);
2001	}
2002	inode->i_blocks = ocfs2_inode_sector_count(inode);
2003	di->i_size = cpu_to_le64((u64)i_size_read(inode));
2004	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2005	di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
2006	di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 
2007	ocfs2_journal_dirty(handle, wc->w_di_bh);
2008
2009	ocfs2_commit_trans(osb, handle);
2010
2011	ocfs2_run_deallocs(osb, &wc->w_dealloc);
2012
2013	ocfs2_free_write_ctxt(wc);
2014
2015	return copied;
2016}
2017
2018static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2019			   loff_t pos, unsigned len, unsigned copied,
2020			   struct page *page, void *fsdata)
2021{
2022	int ret;
2023	struct inode *inode = mapping->host;
2024
2025	ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
2026
2027	up_write(&OCFS2_I(inode)->ip_alloc_sem);
2028	ocfs2_inode_unlock(inode, 1);
2029
2030	return ret;
2031}
2032
2033const struct address_space_operations ocfs2_aops = {
2034	.readpage		= ocfs2_readpage,
2035	.readpages		= ocfs2_readpages,
2036	.writepage		= ocfs2_writepage,
2037	.write_begin		= ocfs2_write_begin,
2038	.write_end		= ocfs2_write_end,
2039	.bmap			= ocfs2_bmap,
2040	.direct_IO		= ocfs2_direct_IO,
2041	.invalidatepage		= ocfs2_invalidatepage,
2042	.releasepage		= ocfs2_releasepage,
2043	.migratepage		= buffer_migrate_page,
2044	.is_partially_uptodate	= block_is_partially_uptodate,
2045	.error_remove_page	= generic_error_remove_page,
2046};