1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* -*- mode: c; c-basic-offset: 8; -*-
   3 * vim: noexpandtab sw=8 ts=8 sts=0:
   4 *
   5 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
   6 */
   7
   8#include <linux/fs.h>
   9#include <linux/slab.h>
  10#include <linux/highmem.h>
  11#include <linux/pagemap.h>
  12#include <asm/byteorder.h>
  13#include <linux/swap.h>
  14#include <linux/mpage.h>
  15#include <linux/quotaops.h>
  16#include <linux/blkdev.h>
  17#include <linux/uio.h>
  18#include <linux/mm.h>
  19
  20#include <cluster/masklog.h>
  21
  22#include "ocfs2.h"
  23
  24#include "alloc.h"
  25#include "aops.h"
  26#include "dlmglue.h"
  27#include "extent_map.h"
  28#include "file.h"
  29#include "inode.h"
  30#include "journal.h"
  31#include "suballoc.h"
  32#include "super.h"
  33#include "symlink.h"
  34#include "refcounttree.h"
  35#include "ocfs2_trace.h"
  36
  37#include "buffer_head_io.h"
  38#include "dir.h"
  39#include "namei.h"
  40#include "sysfile.h"
  41
  42static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
  43				   struct buffer_head *bh_result, int create)
  44{
  45	int err = -EIO;
  46	int status;
  47	struct ocfs2_dinode *fe = NULL;
  48	struct buffer_head *bh = NULL;
  49	struct buffer_head *buffer_cache_bh = NULL;
  50	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  51	void *kaddr;
  52
  53	trace_ocfs2_symlink_get_block(
  54			(unsigned long long)OCFS2_I(inode)->ip_blkno,
  55			(unsigned long long)iblock, bh_result, create);
  56
  57	BUG_ON(ocfs2_inode_is_fast_symlink(inode));
  58
  59	if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
  60		mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
  61		     (unsigned long long)iblock);
  62		goto bail;
  63	}
  64
  65	status = ocfs2_read_inode_block(inode, &bh);
  66	if (status < 0) {
  67		mlog_errno(status);
  68		goto bail;
  69	}
  70	fe = (struct ocfs2_dinode *) bh->b_data;
  71
  72	if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
  73						    le32_to_cpu(fe->i_clusters))) {
  74		err = -ENOMEM;
  75		mlog(ML_ERROR, "block offset is outside the allocated size: "
  76		     "%llu\n", (unsigned long long)iblock);
  77		goto bail;
  78	}
  79
  80	/* We don't use the page cache to create symlink data, so if
  81	 * need be, copy it over from the buffer cache. */
  82	if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
  83		u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
  84			    iblock;
  85		buffer_cache_bh = sb_getblk(osb->sb, blkno);
  86		if (!buffer_cache_bh) {
  87			err = -ENOMEM;
  88			mlog(ML_ERROR, "couldn't getblock for symlink!\n");
  89			goto bail;
  90		}
  91
  92		/* we haven't locked out transactions, so a commit
  93		 * could've happened. Since we've got a reference on
  94		 * the bh, even if it commits while we're doing the
  95		 * copy, the data is still good. */
  96		if (buffer_jbd(buffer_cache_bh)
  97		    && ocfs2_inode_is_new(inode)) {
  98			kaddr = kmap_atomic(bh_result->b_page);
  99			if (!kaddr) {
 100				mlog(ML_ERROR, "couldn't kmap!\n");
 101				goto bail;
 102			}
 103			memcpy(kaddr + (bh_result->b_size * iblock),
 104			       buffer_cache_bh->b_data,
 105			       bh_result->b_size);
 106			kunmap_atomic(kaddr);
 107			set_buffer_uptodate(bh_result);
 108		}
 109		brelse(buffer_cache_bh);
 110	}
 111
 112	map_bh(bh_result, inode->i_sb,
 113	       le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
 114
 115	err = 0;
 116
 117bail:
 118	brelse(bh);
 119
 120	return err;
 121}
 122
 123static int ocfs2_lock_get_block(struct inode *inode, sector_t iblock,
 124		    struct buffer_head *bh_result, int create)
 125{
 126	int ret = 0;
 127	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 128
 129	down_read(&oi->ip_alloc_sem);
 130	ret = ocfs2_get_block(inode, iblock, bh_result, create);
 131	up_read(&oi->ip_alloc_sem);
 132
 133	return ret;
 134}
 135
 136int ocfs2_get_block(struct inode *inode, sector_t iblock,
 137		    struct buffer_head *bh_result, int create)
 138{
 139	int err = 0;
 140	unsigned int ext_flags;
 141	u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
 142	u64 p_blkno, count, past_eof;
 143	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 144
 145	trace_ocfs2_get_block((unsigned long long)OCFS2_I(inode)->ip_blkno,
 146			      (unsigned long long)iblock, bh_result, create);
 147
 148	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
 149		mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
 150		     inode, inode->i_ino);
 151
 152	if (S_ISLNK(inode->i_mode)) {
 153		/* this always does I/O for some reason. */
 154		err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
 155		goto bail;
 156	}
 157
 158	err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
 159					  &ext_flags);
 160	if (err) {
 161		mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
 162		     "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
 163		     (unsigned long long)p_blkno);
 164		goto bail;
 165	}
 166
 167	if (max_blocks < count)
 168		count = max_blocks;
 169
 170	/*
 171	 * ocfs2 never allocates in this function - the only time we
 172	 * need to use BH_New is when we're extending i_size on a file
 173	 * system which doesn't support holes, in which case BH_New
 174	 * allows __block_write_begin() to zero.
 175	 *
 176	 * If we see this on a sparse file system, then a truncate has
 177	 * raced us and removed the cluster. In this case, we clear
 178	 * the buffers dirty and uptodate bits and let the buffer code
 179	 * ignore it as a hole.
 180	 */
 181	if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
 182		clear_buffer_dirty(bh_result);
 183		clear_buffer_uptodate(bh_result);
 184		goto bail;
 185	}
 186
 187	/* Treat the unwritten extent as a hole for zeroing purposes. */
 188	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 189		map_bh(bh_result, inode->i_sb, p_blkno);
 190
 191	bh_result->b_size = count << inode->i_blkbits;
 192
 193	if (!ocfs2_sparse_alloc(osb)) {
 194		if (p_blkno == 0) {
 195			err = -EIO;
 196			mlog(ML_ERROR,
 197			     "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
 198			     (unsigned long long)iblock,
 199			     (unsigned long long)p_blkno,
 200			     (unsigned long long)OCFS2_I(inode)->ip_blkno);
 201			mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
 202			dump_stack();
 203			goto bail;
 204		}
 205	}
 206
 207	past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
 208
 209	trace_ocfs2_get_block_end((unsigned long long)OCFS2_I(inode)->ip_blkno,
 210				  (unsigned long long)past_eof);
 211	if (create && (iblock >= past_eof))
 212		set_buffer_new(bh_result);
 213
 214bail:
 215	if (err < 0)
 216		err = -EIO;
 217
 218	return err;
 219}
 220
 221int ocfs2_read_inline_data(struct inode *inode, struct page *page,
 222			   struct buffer_head *di_bh)
 223{
 224	void *kaddr;
 225	loff_t size;
 226	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 227
 228	if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
 229		ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag\n",
 230			    (unsigned long long)OCFS2_I(inode)->ip_blkno);
 231		return -EROFS;
 232	}
 233
 234	size = i_size_read(inode);
 235
 236	if (size > PAGE_SIZE ||
 237	    size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
 238		ocfs2_error(inode->i_sb,
 239			    "Inode %llu has with inline data has bad size: %Lu\n",
 240			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
 241			    (unsigned long long)size);
 242		return -EROFS;
 243	}
 244
 245	kaddr = kmap_atomic(page);
 246	if (size)
 247		memcpy(kaddr, di->id2.i_data.id_data, size);
 248	/* Clear the remaining part of the page */
 249	memset(kaddr + size, 0, PAGE_SIZE - size);
 250	flush_dcache_page(page);
 251	kunmap_atomic(kaddr);
 252
 253	SetPageUptodate(page);
 254
 255	return 0;
 256}
 257
 258static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
 259{
 260	int ret;
 261	struct buffer_head *di_bh = NULL;
 262
 263	BUG_ON(!PageLocked(page));
 264	BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
 265
 266	ret = ocfs2_read_inode_block(inode, &di_bh);
 267	if (ret) {
 268		mlog_errno(ret);
 269		goto out;
 270	}
 271
 272	ret = ocfs2_read_inline_data(inode, page, di_bh);
 273out:
 274	unlock_page(page);
 275
 276	brelse(di_bh);
 277	return ret;
 278}
 279
 280static int ocfs2_readpage(struct file *file, struct page *page)
 281{
 282	struct inode *inode = page->mapping->host;
 283	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 284	loff_t start = (loff_t)page->index << PAGE_SHIFT;
 285	int ret, unlock = 1;
 286
 287	trace_ocfs2_readpage((unsigned long long)oi->ip_blkno,
 288			     (page ? page->index : 0));
 289
 290	ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
 291	if (ret != 0) {
 292		if (ret == AOP_TRUNCATED_PAGE)
 293			unlock = 0;
 294		mlog_errno(ret);
 295		goto out;
 296	}
 297
 298	if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
 299		/*
 300		 * Unlock the page and cycle ip_alloc_sem so that we don't
 301		 * busyloop waiting for ip_alloc_sem to unlock
 302		 */
 303		ret = AOP_TRUNCATED_PAGE;
 304		unlock_page(page);
 305		unlock = 0;
 306		down_read(&oi->ip_alloc_sem);
 307		up_read(&oi->ip_alloc_sem);
 308		goto out_inode_unlock;
 309	}
 310
 311	/*
 312	 * i_size might have just been updated as we grabed the meta lock.  We
 313	 * might now be discovering a truncate that hit on another node.
 314	 * block_read_full_page->get_block freaks out if it is asked to read
 315	 * beyond the end of a file, so we check here.  Callers
 316	 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
 317	 * and notice that the page they just read isn't needed.
 318	 *
 319	 * XXX sys_readahead() seems to get that wrong?
 320	 */
 321	if (start >= i_size_read(inode)) {
 322		zero_user(page, 0, PAGE_SIZE);
 323		SetPageUptodate(page);
 324		ret = 0;
 325		goto out_alloc;
 326	}
 327
 328	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 329		ret = ocfs2_readpage_inline(inode, page);
 330	else
 331		ret = block_read_full_page(page, ocfs2_get_block);
 332	unlock = 0;
 333
 334out_alloc:
 335	up_read(&oi->ip_alloc_sem);
 336out_inode_unlock:
 337	ocfs2_inode_unlock(inode, 0);
 338out:
 339	if (unlock)
 340		unlock_page(page);
 341	return ret;
 342}
 343
 344/*
 345 * This is used only for read-ahead. Failures or difficult to handle
 346 * situations are safe to ignore.
 347 *
 348 * Right now, we don't bother with BH_Boundary - in-inode extent lists
 349 * are quite large (243 extents on 4k blocks), so most inodes don't
 350 * grow out to a tree. If need be, detecting boundary extents could
 351 * trivially be added in a future version of ocfs2_get_block().
 352 */
 353static void ocfs2_readahead(struct readahead_control *rac)
 354{
 355	int ret;
 356	struct inode *inode = rac->mapping->host;
 357	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 358
 359	/*
 360	 * Use the nonblocking flag for the dlm code to avoid page
 361	 * lock inversion, but don't bother with retrying.
 362	 */
 363	ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
 364	if (ret)
 365		return;
 366
 367	if (down_read_trylock(&oi->ip_alloc_sem) == 0)
 368		goto out_unlock;
 369
 370	/*
 371	 * Don't bother with inline-data. There isn't anything
 372	 * to read-ahead in that case anyway...
 373	 */
 374	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 375		goto out_up;
 376
 377	/*
 378	 * Check whether a remote node truncated this file - we just
 379	 * drop out in that case as it's not worth handling here.
 380	 */
 381	if (readahead_pos(rac) >= i_size_read(inode))
 382		goto out_up;
 383
 384	mpage_readahead(rac, ocfs2_get_block);
 385
 386out_up:
 387	up_read(&oi->ip_alloc_sem);
 388out_unlock:
 389	ocfs2_inode_unlock(inode, 0);
 390}
 391
 392/* Note: Because we don't support holes, our allocation has
 393 * already happened (allocation writes zeros to the file data)
 394 * so we don't have to worry about ordered writes in
 395 * ocfs2_writepage.
 396 *
 397 * ->writepage is called during the process of invalidating the page cache
 398 * during blocked lock processing.  It can't block on any cluster locks
 399 * to during block mapping.  It's relying on the fact that the block
 400 * mapping can't have disappeared under the dirty pages that it is
 401 * being asked to write back.
 402 */
 403static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
 
 404{
 405	trace_ocfs2_writepage(
 406		(unsigned long long)OCFS2_I(page->mapping->host)->ip_blkno,
 407		page->index);
 408
 409	return block_write_full_page(page, ocfs2_get_block, wbc);
 410}
 411
 412/* Taken from ext3. We don't necessarily need the full blown
 413 * functionality yet, but IMHO it's better to cut and paste the whole
 414 * thing so we can avoid introducing our own bugs (and easily pick up
 415 * their fixes when they happen) --Mark */
 416int walk_page_buffers(	handle_t *handle,
 417			struct buffer_head *head,
 418			unsigned from,
 419			unsigned to,
 420			int *partial,
 421			int (*fn)(	handle_t *handle,
 422					struct buffer_head *bh))
 423{
 424	struct buffer_head *bh;
 425	unsigned block_start, block_end;
 426	unsigned blocksize = head->b_size;
 427	int err, ret = 0;
 428	struct buffer_head *next;
 429
 430	for (	bh = head, block_start = 0;
 431		ret == 0 && (bh != head || !block_start);
 432	    	block_start = block_end, bh = next)
 433	{
 434		next = bh->b_this_page;
 435		block_end = block_start + blocksize;
 436		if (block_end <= from || block_start >= to) {
 437			if (partial && !buffer_uptodate(bh))
 438				*partial = 1;
 439			continue;
 440		}
 441		err = (*fn)(handle, bh);
 442		if (!ret)
 443			ret = err;
 444	}
 445	return ret;
 446}
 447
 448static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
 449{
 450	sector_t status;
 451	u64 p_blkno = 0;
 452	int err = 0;
 453	struct inode *inode = mapping->host;
 454
 455	trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno,
 456			 (unsigned long long)block);
 457
 458	/*
 459	 * The swap code (ab-)uses ->bmap to get a block mapping and then
 460	 * bypasseѕ the file system for actual I/O.  We really can't allow
 461	 * that on refcounted inodes, so we have to skip out here.  And yes,
 462	 * 0 is the magic code for a bmap error..
 463	 */
 464	if (ocfs2_is_refcount_inode(inode))
 465		return 0;
 466
 467	/* We don't need to lock journal system files, since they aren't
 468	 * accessed concurrently from multiple nodes.
 469	 */
 470	if (!INODE_JOURNAL(inode)) {
 471		err = ocfs2_inode_lock(inode, NULL, 0);
 472		if (err) {
 473			if (err != -ENOENT)
 474				mlog_errno(err);
 475			goto bail;
 476		}
 477		down_read(&OCFS2_I(inode)->ip_alloc_sem);
 478	}
 479
 480	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
 481		err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
 482						  NULL);
 483
 484	if (!INODE_JOURNAL(inode)) {
 485		up_read(&OCFS2_I(inode)->ip_alloc_sem);
 486		ocfs2_inode_unlock(inode, 0);
 487	}
 488
 489	if (err) {
 490		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
 491		     (unsigned long long)block);
 492		mlog_errno(err);
 493		goto bail;
 494	}
 495
 496bail:
 497	status = err ? 0 : p_blkno;
 498
 499	return status;
 500}
 501
 502static int ocfs2_releasepage(struct page *page, gfp_t wait)
 503{
 504	if (!page_has_buffers(page))
 505		return 0;
 506	return try_to_free_buffers(page);
 507}
 508
 509static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
 510					    u32 cpos,
 511					    unsigned int *start,
 512					    unsigned int *end)
 513{
 514	unsigned int cluster_start = 0, cluster_end = PAGE_SIZE;
 515
 516	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits)) {
 517		unsigned int cpp;
 518
 519		cpp = 1 << (PAGE_SHIFT - osb->s_clustersize_bits);
 520
 521		cluster_start = cpos % cpp;
 522		cluster_start = cluster_start << osb->s_clustersize_bits;
 523
 524		cluster_end = cluster_start + osb->s_clustersize;
 525	}
 526
 527	BUG_ON(cluster_start > PAGE_SIZE);
 528	BUG_ON(cluster_end > PAGE_SIZE);
 529
 530	if (start)
 531		*start = cluster_start;
 532	if (end)
 533		*end = cluster_end;
 534}
 535
 536/*
 537 * 'from' and 'to' are the region in the page to avoid zeroing.
 538 *
 539 * If pagesize > clustersize, this function will avoid zeroing outside
 540 * of the cluster boundary.
 541 *
 542 * from == to == 0 is code for "zero the entire cluster region"
 543 */
 544static void ocfs2_clear_page_regions(struct page *page,
 545				     struct ocfs2_super *osb, u32 cpos,
 546				     unsigned from, unsigned to)
 547{
 548	void *kaddr;
 549	unsigned int cluster_start, cluster_end;
 550
 551	ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
 552
 553	kaddr = kmap_atomic(page);
 554
 555	if (from || to) {
 556		if (from > cluster_start)
 557			memset(kaddr + cluster_start, 0, from - cluster_start);
 558		if (to < cluster_end)
 559			memset(kaddr + to, 0, cluster_end - to);
 560	} else {
 561		memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
 562	}
 563
 564	kunmap_atomic(kaddr);
 565}
 566
 567/*
 568 * Nonsparse file systems fully allocate before we get to the write
 569 * code. This prevents ocfs2_write() from tagging the write as an
 570 * allocating one, which means ocfs2_map_page_blocks() might try to
 571 * read-in the blocks at the tail of our file. Avoid reading them by
 572 * testing i_size against each block offset.
 573 */
 574static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
 575				 unsigned int block_start)
 576{
 577	u64 offset = page_offset(page) + block_start;
 578
 579	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
 580		return 1;
 581
 582	if (i_size_read(inode) > offset)
 583		return 1;
 584
 585	return 0;
 586}
 587
 588/*
 589 * Some of this taken from __block_write_begin(). We already have our
 590 * mapping by now though, and the entire write will be allocating or
 591 * it won't, so not much need to use BH_New.
 592 *
 593 * This will also skip zeroing, which is handled externally.
 594 */
 595int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
 596			  struct inode *inode, unsigned int from,
 597			  unsigned int to, int new)
 598{
 
 599	int ret = 0;
 600	struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
 601	unsigned int block_end, block_start;
 602	unsigned int bsize = i_blocksize(inode);
 603
 604	if (!page_has_buffers(page))
 605		create_empty_buffers(page, bsize, 0);
 
 606
 607	head = page_buffers(page);
 608	for (bh = head, block_start = 0; bh != head || !block_start;
 609	     bh = bh->b_this_page, block_start += bsize) {
 610		block_end = block_start + bsize;
 611
 612		clear_buffer_new(bh);
 613
 614		/*
 615		 * Ignore blocks outside of our i/o range -
 616		 * they may belong to unallocated clusters.
 617		 */
 618		if (block_start >= to || block_end <= from) {
 619			if (PageUptodate(page))
 620				set_buffer_uptodate(bh);
 621			continue;
 622		}
 623
 624		/*
 625		 * For an allocating write with cluster size >= page
 626		 * size, we always write the entire page.
 627		 */
 628		if (new)
 629			set_buffer_new(bh);
 630
 631		if (!buffer_mapped(bh)) {
 632			map_bh(bh, inode->i_sb, *p_blkno);
 633			clean_bdev_bh_alias(bh);
 634		}
 635
 636		if (PageUptodate(page)) {
 637			if (!buffer_uptodate(bh))
 638				set_buffer_uptodate(bh);
 639		} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
 640			   !buffer_new(bh) &&
 641			   ocfs2_should_read_blk(inode, page, block_start) &&
 642			   (block_start < from || block_end > to)) {
 643			ll_rw_block(REQ_OP_READ, 0, 1, &bh);
 644			*wait_bh++=bh;
 645		}
 646
 647		*p_blkno = *p_blkno + 1;
 648	}
 649
 650	/*
 651	 * If we issued read requests - let them complete.
 652	 */
 653	while(wait_bh > wait) {
 654		wait_on_buffer(*--wait_bh);
 655		if (!buffer_uptodate(*wait_bh))
 656			ret = -EIO;
 657	}
 658
 659	if (ret == 0 || !new)
 660		return ret;
 661
 662	/*
 663	 * If we get -EIO above, zero out any newly allocated blocks
 664	 * to avoid exposing stale data.
 665	 */
 666	bh = head;
 667	block_start = 0;
 668	do {
 669		block_end = block_start + bsize;
 670		if (block_end <= from)
 671			goto next_bh;
 672		if (block_start >= to)
 673			break;
 674
 675		zero_user(page, block_start, bh->b_size);
 676		set_buffer_uptodate(bh);
 677		mark_buffer_dirty(bh);
 678
 679next_bh:
 680		block_start = block_end;
 681		bh = bh->b_this_page;
 682	} while (bh != head);
 683
 684	return ret;
 685}
 686
 687#if (PAGE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
 688#define OCFS2_MAX_CTXT_PAGES	1
 689#else
 690#define OCFS2_MAX_CTXT_PAGES	(OCFS2_MAX_CLUSTERSIZE / PAGE_SIZE)
 691#endif
 692
 693#define OCFS2_MAX_CLUSTERS_PER_PAGE	(PAGE_SIZE / OCFS2_MIN_CLUSTERSIZE)
 694
 695struct ocfs2_unwritten_extent {
 696	struct list_head	ue_node;
 697	struct list_head	ue_ip_node;
 698	u32			ue_cpos;
 699	u32			ue_phys;
 700};
 701
 702/*
 703 * Describe the state of a single cluster to be written to.
 704 */
 705struct ocfs2_write_cluster_desc {
 706	u32		c_cpos;
 707	u32		c_phys;
 708	/*
 709	 * Give this a unique field because c_phys eventually gets
 710	 * filled.
 711	 */
 712	unsigned	c_new;
 713	unsigned	c_clear_unwritten;
 714	unsigned	c_needs_zero;
 715};
 716
 717struct ocfs2_write_ctxt {
 718	/* Logical cluster position / len of write */
 719	u32				w_cpos;
 720	u32				w_clen;
 721
 722	/* First cluster allocated in a nonsparse extend */
 723	u32				w_first_new_cpos;
 724
 725	/* Type of caller. Must be one of buffer, mmap, direct.  */
 726	ocfs2_write_type_t		w_type;
 727
 728	struct ocfs2_write_cluster_desc	w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
 729
 730	/*
 731	 * This is true if page_size > cluster_size.
 732	 *
 733	 * It triggers a set of special cases during write which might
 734	 * have to deal with allocating writes to partial pages.
 735	 */
 736	unsigned int			w_large_pages;
 737
 738	/*
 739	 * Pages involved in this write.
 740	 *
 741	 * w_target_page is the page being written to by the user.
 742	 *
 743	 * w_pages is an array of pages which always contains
 744	 * w_target_page, and in the case of an allocating write with
 745	 * page_size < cluster size, it will contain zero'd and mapped
 746	 * pages adjacent to w_target_page which need to be written
 747	 * out in so that future reads from that region will get
 748	 * zero's.
 749	 */
 750	unsigned int			w_num_pages;
 751	struct page			*w_pages[OCFS2_MAX_CTXT_PAGES];
 752	struct page			*w_target_page;
 753
 754	/*
 755	 * w_target_locked is used for page_mkwrite path indicating no unlocking
 756	 * against w_target_page in ocfs2_write_end_nolock.
 757	 */
 758	unsigned int			w_target_locked:1;
 759
 760	/*
 761	 * ocfs2_write_end() uses this to know what the real range to
 762	 * write in the target should be.
 763	 */
 764	unsigned int			w_target_from;
 765	unsigned int			w_target_to;
 766
 767	/*
 768	 * We could use journal_current_handle() but this is cleaner,
 769	 * IMHO -Mark
 770	 */
 771	handle_t			*w_handle;
 772
 773	struct buffer_head		*w_di_bh;
 774
 775	struct ocfs2_cached_dealloc_ctxt w_dealloc;
 776
 777	struct list_head		w_unwritten_list;
 778	unsigned int			w_unwritten_count;
 779};
 780
 781void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
 782{
 783	int i;
 784
 785	for(i = 0; i < num_pages; i++) {
 786		if (pages[i]) {
 787			unlock_page(pages[i]);
 788			mark_page_accessed(pages[i]);
 789			put_page(pages[i]);
 790		}
 791	}
 792}
 793
 794static void ocfs2_unlock_pages(struct ocfs2_write_ctxt *wc)
 795{
 796	int i;
 797
 798	/*
 799	 * w_target_locked is only set to true in the page_mkwrite() case.
 800	 * The intent is to allow us to lock the target page from write_begin()
 801	 * to write_end(). The caller must hold a ref on w_target_page.
 802	 */
 803	if (wc->w_target_locked) {
 804		BUG_ON(!wc->w_target_page);
 805		for (i = 0; i < wc->w_num_pages; i++) {
 806			if (wc->w_target_page == wc->w_pages[i]) {
 807				wc->w_pages[i] = NULL;
 808				break;
 809			}
 810		}
 811		mark_page_accessed(wc->w_target_page);
 812		put_page(wc->w_target_page);
 813	}
 814	ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
 815}
 816
 817static void ocfs2_free_unwritten_list(struct inode *inode,
 818				 struct list_head *head)
 819{
 820	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 821	struct ocfs2_unwritten_extent *ue = NULL, *tmp = NULL;
 822
 823	list_for_each_entry_safe(ue, tmp, head, ue_node) {
 824		list_del(&ue->ue_node);
 825		spin_lock(&oi->ip_lock);
 826		list_del(&ue->ue_ip_node);
 827		spin_unlock(&oi->ip_lock);
 828		kfree(ue);
 829	}
 830}
 831
 832static void ocfs2_free_write_ctxt(struct inode *inode,
 833				  struct ocfs2_write_ctxt *wc)
 834{
 835	ocfs2_free_unwritten_list(inode, &wc->w_unwritten_list);
 836	ocfs2_unlock_pages(wc);
 837	brelse(wc->w_di_bh);
 838	kfree(wc);
 839}
 840
 841static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
 842				  struct ocfs2_super *osb, loff_t pos,
 843				  unsigned len, ocfs2_write_type_t type,
 844				  struct buffer_head *di_bh)
 845{
 846	u32 cend;
 847	struct ocfs2_write_ctxt *wc;
 848
 849	wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
 850	if (!wc)
 851		return -ENOMEM;
 852
 853	wc->w_cpos = pos >> osb->s_clustersize_bits;
 854	wc->w_first_new_cpos = UINT_MAX;
 855	cend = (pos + len - 1) >> osb->s_clustersize_bits;
 856	wc->w_clen = cend - wc->w_cpos + 1;
 857	get_bh(di_bh);
 858	wc->w_di_bh = di_bh;
 859	wc->w_type = type;
 860
 861	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits))
 862		wc->w_large_pages = 1;
 863	else
 864		wc->w_large_pages = 0;
 865
 866	ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
 867	INIT_LIST_HEAD(&wc->w_unwritten_list);
 868
 869	*wcp = wc;
 870
 871	return 0;
 872}
 873
 874/*
 875 * If a page has any new buffers, zero them out here, and mark them uptodate
 876 * and dirty so they'll be written out (in order to prevent uninitialised
 877 * block data from leaking). And clear the new bit.
 878 */
 879static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
 880{
 881	unsigned int block_start, block_end;
 882	struct buffer_head *head, *bh;
 883
 884	BUG_ON(!PageLocked(page));
 885	if (!page_has_buffers(page))
 886		return;
 887
 888	bh = head = page_buffers(page);
 889	block_start = 0;
 890	do {
 891		block_end = block_start + bh->b_size;
 892
 893		if (buffer_new(bh)) {
 894			if (block_end > from && block_start < to) {
 895				if (!PageUptodate(page)) {
 896					unsigned start, end;
 897
 898					start = max(from, block_start);
 899					end = min(to, block_end);
 900
 901					zero_user_segment(page, start, end);
 902					set_buffer_uptodate(bh);
 903				}
 904
 905				clear_buffer_new(bh);
 906				mark_buffer_dirty(bh);
 907			}
 908		}
 909
 910		block_start = block_end;
 911		bh = bh->b_this_page;
 912	} while (bh != head);
 913}
 914
 915/*
 916 * Only called when we have a failure during allocating write to write
 917 * zero's to the newly allocated region.
 918 */
 919static void ocfs2_write_failure(struct inode *inode,
 920				struct ocfs2_write_ctxt *wc,
 921				loff_t user_pos, unsigned user_len)
 922{
 923	int i;
 924	unsigned from = user_pos & (PAGE_SIZE - 1),
 925		to = user_pos + user_len;
 926	struct page *tmppage;
 927
 928	if (wc->w_target_page)
 929		ocfs2_zero_new_buffers(wc->w_target_page, from, to);
 930
 931	for(i = 0; i < wc->w_num_pages; i++) {
 932		tmppage = wc->w_pages[i];
 933
 934		if (tmppage && page_has_buffers(tmppage)) {
 935			if (ocfs2_should_order_data(inode))
 936				ocfs2_jbd2_inode_add_write(wc->w_handle, inode,
 937							   user_pos, user_len);
 938
 939			block_commit_write(tmppage, from, to);
 940		}
 941	}
 942}
 943
 944static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
 945					struct ocfs2_write_ctxt *wc,
 946					struct page *page, u32 cpos,
 947					loff_t user_pos, unsigned user_len,
 948					int new)
 949{
 950	int ret;
 951	unsigned int map_from = 0, map_to = 0;
 952	unsigned int cluster_start, cluster_end;
 953	unsigned int user_data_from = 0, user_data_to = 0;
 954
 955	ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
 956					&cluster_start, &cluster_end);
 957
 958	/* treat the write as new if the a hole/lseek spanned across
 959	 * the page boundary.
 960	 */
 961	new = new | ((i_size_read(inode) <= page_offset(page)) &&
 962			(page_offset(page) <= user_pos));
 963
 964	if (page == wc->w_target_page) {
 965		map_from = user_pos & (PAGE_SIZE - 1);
 966		map_to = map_from + user_len;
 967
 968		if (new)
 969			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
 970						    cluster_start, cluster_end,
 971						    new);
 972		else
 973			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
 974						    map_from, map_to, new);
 975		if (ret) {
 976			mlog_errno(ret);
 977			goto out;
 978		}
 979
 980		user_data_from = map_from;
 981		user_data_to = map_to;
 982		if (new) {
 983			map_from = cluster_start;
 984			map_to = cluster_end;
 985		}
 986	} else {
 987		/*
 988		 * If we haven't allocated the new page yet, we
 989		 * shouldn't be writing it out without copying user
 990		 * data. This is likely a math error from the caller.
 991		 */
 992		BUG_ON(!new);
 993
 994		map_from = cluster_start;
 995		map_to = cluster_end;
 996
 997		ret = ocfs2_map_page_blocks(page, p_blkno, inode,
 998					    cluster_start, cluster_end, new);
 999		if (ret) {
1000			mlog_errno(ret);
1001			goto out;
1002		}
1003	}
1004
1005	/*
1006	 * Parts of newly allocated pages need to be zero'd.
1007	 *
1008	 * Above, we have also rewritten 'to' and 'from' - as far as
1009	 * the rest of the function is concerned, the entire cluster
1010	 * range inside of a page needs to be written.
1011	 *
1012	 * We can skip this if the page is up to date - it's already
1013	 * been zero'd from being read in as a hole.
1014	 */
1015	if (new && !PageUptodate(page))
1016		ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1017					 cpos, user_data_from, user_data_to);
1018
1019	flush_dcache_page(page);
1020
1021out:
1022	return ret;
1023}
1024
1025/*
1026 * This function will only grab one clusters worth of pages.
1027 */
1028static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1029				      struct ocfs2_write_ctxt *wc,
1030				      u32 cpos, loff_t user_pos,
1031				      unsigned user_len, int new,
1032				      struct page *mmap_page)
1033{
1034	int ret = 0, i;
1035	unsigned long start, target_index, end_index, index;
1036	struct inode *inode = mapping->host;
1037	loff_t last_byte;
1038
1039	target_index = user_pos >> PAGE_SHIFT;
1040
1041	/*
1042	 * Figure out how many pages we'll be manipulating here. For
1043	 * non allocating write, we just change the one
1044	 * page. Otherwise, we'll need a whole clusters worth.  If we're
1045	 * writing past i_size, we only need enough pages to cover the
1046	 * last page of the write.
1047	 */
1048	if (new) {
1049		wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1050		start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1051		/*
1052		 * We need the index *past* the last page we could possibly
1053		 * touch.  This is the page past the end of the write or
1054		 * i_size, whichever is greater.
1055		 */
1056		last_byte = max(user_pos + user_len, i_size_read(inode));
1057		BUG_ON(last_byte < 1);
1058		end_index = ((last_byte - 1) >> PAGE_SHIFT) + 1;
1059		if ((start + wc->w_num_pages) > end_index)
1060			wc->w_num_pages = end_index - start;
1061	} else {
1062		wc->w_num_pages = 1;
1063		start = target_index;
1064	}
1065	end_index = (user_pos + user_len - 1) >> PAGE_SHIFT;
1066
1067	for(i = 0; i < wc->w_num_pages; i++) {
1068		index = start + i;
1069
1070		if (index >= target_index && index <= end_index &&
1071		    wc->w_type == OCFS2_WRITE_MMAP) {
1072			/*
1073			 * ocfs2_pagemkwrite() is a little different
1074			 * and wants us to directly use the page
1075			 * passed in.
1076			 */
1077			lock_page(mmap_page);
1078
1079			/* Exit and let the caller retry */
1080			if (mmap_page->mapping != mapping) {
1081				WARN_ON(mmap_page->mapping);
1082				unlock_page(mmap_page);
1083				ret = -EAGAIN;
1084				goto out;
1085			}
1086
1087			get_page(mmap_page);
1088			wc->w_pages[i] = mmap_page;
1089			wc->w_target_locked = true;
1090		} else if (index >= target_index && index <= end_index &&
1091			   wc->w_type == OCFS2_WRITE_DIRECT) {
1092			/* Direct write has no mapping page. */
1093			wc->w_pages[i] = NULL;
1094			continue;
1095		} else {
1096			wc->w_pages[i] = find_or_create_page(mapping, index,
1097							     GFP_NOFS);
1098			if (!wc->w_pages[i]) {
1099				ret = -ENOMEM;
1100				mlog_errno(ret);
1101				goto out;
1102			}
1103		}
1104		wait_for_stable_page(wc->w_pages[i]);
1105
1106		if (index == target_index)
1107			wc->w_target_page = wc->w_pages[i];
1108	}
1109out:
1110	if (ret)
1111		wc->w_target_locked = false;
1112	return ret;
1113}
1114
1115/*
1116 * Prepare a single cluster for write one cluster into the file.
1117 */
1118static int ocfs2_write_cluster(struct address_space *mapping,
1119			       u32 *phys, unsigned int new,
1120			       unsigned int clear_unwritten,
1121			       unsigned int should_zero,
1122			       struct ocfs2_alloc_context *data_ac,
1123			       struct ocfs2_alloc_context *meta_ac,
1124			       struct ocfs2_write_ctxt *wc, u32 cpos,
1125			       loff_t user_pos, unsigned user_len)
1126{
1127	int ret, i;
1128	u64 p_blkno;
1129	struct inode *inode = mapping->host;
1130	struct ocfs2_extent_tree et;
1131	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
1132
1133	if (new) {
1134		u32 tmp_pos;
1135
1136		/*
1137		 * This is safe to call with the page locks - it won't take
1138		 * any additional semaphores or cluster locks.
1139		 */
1140		tmp_pos = cpos;
1141		ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1142					   &tmp_pos, 1, !clear_unwritten,
1143					   wc->w_di_bh, wc->w_handle,
1144					   data_ac, meta_ac, NULL);
1145		/*
1146		 * This shouldn't happen because we must have already
1147		 * calculated the correct meta data allocation required. The
1148		 * internal tree allocation code should know how to increase
1149		 * transaction credits itself.
1150		 *
1151		 * If need be, we could handle -EAGAIN for a
1152		 * RESTART_TRANS here.
1153		 */
1154		mlog_bug_on_msg(ret == -EAGAIN,
1155				"Inode %llu: EAGAIN return during allocation.\n",
1156				(unsigned long long)OCFS2_I(inode)->ip_blkno);
1157		if (ret < 0) {
1158			mlog_errno(ret);
1159			goto out;
1160		}
1161	} else if (clear_unwritten) {
1162		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1163					      wc->w_di_bh);
1164		ret = ocfs2_mark_extent_written(inode, &et,
1165						wc->w_handle, cpos, 1, *phys,
1166						meta_ac, &wc->w_dealloc);
1167		if (ret < 0) {
1168			mlog_errno(ret);
1169			goto out;
1170		}
1171	}
1172
1173	/*
1174	 * The only reason this should fail is due to an inability to
1175	 * find the extent added.
1176	 */
1177	ret = ocfs2_get_clusters(inode, cpos, phys, NULL, NULL);
1178	if (ret < 0) {
1179		mlog(ML_ERROR, "Get physical blkno failed for inode %llu, "
1180			    "at logical cluster %u",
1181			    (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos);
1182		goto out;
1183	}
1184
1185	BUG_ON(*phys == 0);
1186
1187	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, *phys);
1188	if (!should_zero)
1189		p_blkno += (user_pos >> inode->i_sb->s_blocksize_bits) & (u64)(bpc - 1);
1190
1191	for(i = 0; i < wc->w_num_pages; i++) {
1192		int tmpret;
1193
1194		/* This is the direct io target page. */
1195		if (wc->w_pages[i] == NULL) {
1196			p_blkno++;
1197			continue;
1198		}
1199
1200		tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1201						      wc->w_pages[i], cpos,
1202						      user_pos, user_len,
1203						      should_zero);
1204		if (tmpret) {
1205			mlog_errno(tmpret);
1206			if (ret == 0)
1207				ret = tmpret;
1208		}
1209	}
1210
1211	/*
1212	 * We only have cleanup to do in case of allocating write.
1213	 */
1214	if (ret && new)
1215		ocfs2_write_failure(inode, wc, user_pos, user_len);
1216
1217out:
1218
1219	return ret;
1220}
1221
1222static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1223				       struct ocfs2_alloc_context *data_ac,
1224				       struct ocfs2_alloc_context *meta_ac,
1225				       struct ocfs2_write_ctxt *wc,
1226				       loff_t pos, unsigned len)
1227{
1228	int ret, i;
1229	loff_t cluster_off;
1230	unsigned int local_len = len;
1231	struct ocfs2_write_cluster_desc *desc;
1232	struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1233
1234	for (i = 0; i < wc->w_clen; i++) {
1235		desc = &wc->w_desc[i];
1236
1237		/*
1238		 * We have to make sure that the total write passed in
1239		 * doesn't extend past a single cluster.
1240		 */
1241		local_len = len;
1242		cluster_off = pos & (osb->s_clustersize - 1);
1243		if ((cluster_off + local_len) > osb->s_clustersize)
1244			local_len = osb->s_clustersize - cluster_off;
1245
1246		ret = ocfs2_write_cluster(mapping, &desc->c_phys,
1247					  desc->c_new,
1248					  desc->c_clear_unwritten,
1249					  desc->c_needs_zero,
1250					  data_ac, meta_ac,
1251					  wc, desc->c_cpos, pos, local_len);
1252		if (ret) {
1253			mlog_errno(ret);
1254			goto out;
1255		}
1256
1257		len -= local_len;
1258		pos += local_len;
1259	}
1260
1261	ret = 0;
1262out:
1263	return ret;
1264}
1265
1266/*
1267 * ocfs2_write_end() wants to know which parts of the target page it
1268 * should complete the write on. It's easiest to compute them ahead of
1269 * time when a more complete view of the write is available.
1270 */
1271static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1272					struct ocfs2_write_ctxt *wc,
1273					loff_t pos, unsigned len, int alloc)
1274{
1275	struct ocfs2_write_cluster_desc *desc;
1276
1277	wc->w_target_from = pos & (PAGE_SIZE - 1);
1278	wc->w_target_to = wc->w_target_from + len;
1279
1280	if (alloc == 0)
1281		return;
1282
1283	/*
1284	 * Allocating write - we may have different boundaries based
1285	 * on page size and cluster size.
1286	 *
1287	 * NOTE: We can no longer compute one value from the other as
1288	 * the actual write length and user provided length may be
1289	 * different.
1290	 */
1291
1292	if (wc->w_large_pages) {
1293		/*
1294		 * We only care about the 1st and last cluster within
1295		 * our range and whether they should be zero'd or not. Either
1296		 * value may be extended out to the start/end of a
1297		 * newly allocated cluster.
1298		 */
1299		desc = &wc->w_desc[0];
1300		if (desc->c_needs_zero)
1301			ocfs2_figure_cluster_boundaries(osb,
1302							desc->c_cpos,
1303							&wc->w_target_from,
1304							NULL);
1305
1306		desc = &wc->w_desc[wc->w_clen - 1];
1307		if (desc->c_needs_zero)
1308			ocfs2_figure_cluster_boundaries(osb,
1309							desc->c_cpos,
1310							NULL,
1311							&wc->w_target_to);
1312	} else {
1313		wc->w_target_from = 0;
1314		wc->w_target_to = PAGE_SIZE;
1315	}
1316}
1317
1318/*
1319 * Check if this extent is marked UNWRITTEN by direct io. If so, we need not to
1320 * do the zero work. And should not to clear UNWRITTEN since it will be cleared
1321 * by the direct io procedure.
1322 * If this is a new extent that allocated by direct io, we should mark it in
1323 * the ip_unwritten_list.
1324 */
1325static int ocfs2_unwritten_check(struct inode *inode,
1326				 struct ocfs2_write_ctxt *wc,
1327				 struct ocfs2_write_cluster_desc *desc)
1328{
1329	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1330	struct ocfs2_unwritten_extent *ue = NULL, *new = NULL;
1331	int ret = 0;
1332
1333	if (!desc->c_needs_zero)
1334		return 0;
1335
1336retry:
1337	spin_lock(&oi->ip_lock);
1338	/* Needs not to zero no metter buffer or direct. The one who is zero
1339	 * the cluster is doing zero. And he will clear unwritten after all
1340	 * cluster io finished. */
1341	list_for_each_entry(ue, &oi->ip_unwritten_list, ue_ip_node) {
1342		if (desc->c_cpos == ue->ue_cpos) {
1343			BUG_ON(desc->c_new);
1344			desc->c_needs_zero = 0;
1345			desc->c_clear_unwritten = 0;
1346			goto unlock;
1347		}
1348	}
1349
1350	if (wc->w_type != OCFS2_WRITE_DIRECT)
1351		goto unlock;
1352
1353	if (new == NULL) {
1354		spin_unlock(&oi->ip_lock);
1355		new = kmalloc(sizeof(struct ocfs2_unwritten_extent),
1356			     GFP_NOFS);
1357		if (new == NULL) {
1358			ret = -ENOMEM;
1359			goto out;
1360		}
1361		goto retry;
1362	}
1363	/* This direct write will doing zero. */
1364	new->ue_cpos = desc->c_cpos;
1365	new->ue_phys = desc->c_phys;
1366	desc->c_clear_unwritten = 0;
1367	list_add_tail(&new->ue_ip_node, &oi->ip_unwritten_list);
1368	list_add_tail(&new->ue_node, &wc->w_unwritten_list);
1369	wc->w_unwritten_count++;
1370	new = NULL;
1371unlock:
1372	spin_unlock(&oi->ip_lock);
1373out:
1374	kfree(new);
1375	return ret;
1376}
1377
1378/*
1379 * Populate each single-cluster write descriptor in the write context
1380 * with information about the i/o to be done.
1381 *
1382 * Returns the number of clusters that will have to be allocated, as
1383 * well as a worst case estimate of the number of extent records that
1384 * would have to be created during a write to an unwritten region.
1385 */
1386static int ocfs2_populate_write_desc(struct inode *inode,
1387				     struct ocfs2_write_ctxt *wc,
1388				     unsigned int *clusters_to_alloc,
1389				     unsigned int *extents_to_split)
1390{
1391	int ret;
1392	struct ocfs2_write_cluster_desc *desc;
1393	unsigned int num_clusters = 0;
1394	unsigned int ext_flags = 0;
1395	u32 phys = 0;
1396	int i;
1397
1398	*clusters_to_alloc = 0;
1399	*extents_to_split = 0;
1400
1401	for (i = 0; i < wc->w_clen; i++) {
1402		desc = &wc->w_desc[i];
1403		desc->c_cpos = wc->w_cpos + i;
1404
1405		if (num_clusters == 0) {
1406			/*
1407			 * Need to look up the next extent record.
1408			 */
1409			ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1410						 &num_clusters, &ext_flags);
1411			if (ret) {
1412				mlog_errno(ret);
1413				goto out;
1414			}
1415
1416			/* We should already CoW the refcountd extent. */
1417			BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1418
1419			/*
1420			 * Assume worst case - that we're writing in
1421			 * the middle of the extent.
1422			 *
1423			 * We can assume that the write proceeds from
1424			 * left to right, in which case the extent
1425			 * insert code is smart enough to coalesce the
1426			 * next splits into the previous records created.
1427			 */
1428			if (ext_flags & OCFS2_EXT_UNWRITTEN)
1429				*extents_to_split = *extents_to_split + 2;
1430		} else if (phys) {
1431			/*
1432			 * Only increment phys if it doesn't describe
1433			 * a hole.
1434			 */
1435			phys++;
1436		}
1437
1438		/*
1439		 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1440		 * file that got extended.  w_first_new_cpos tells us
1441		 * where the newly allocated clusters are so we can
1442		 * zero them.
1443		 */
1444		if (desc->c_cpos >= wc->w_first_new_cpos) {
1445			BUG_ON(phys == 0);
1446			desc->c_needs_zero = 1;
1447		}
1448
1449		desc->c_phys = phys;
1450		if (phys == 0) {
1451			desc->c_new = 1;
1452			desc->c_needs_zero = 1;
1453			desc->c_clear_unwritten = 1;
1454			*clusters_to_alloc = *clusters_to_alloc + 1;
1455		}
1456
1457		if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1458			desc->c_clear_unwritten = 1;
1459			desc->c_needs_zero = 1;
1460		}
1461
1462		ret = ocfs2_unwritten_check(inode, wc, desc);
1463		if (ret) {
1464			mlog_errno(ret);
1465			goto out;
1466		}
1467
1468		num_clusters--;
1469	}
1470
1471	ret = 0;
1472out:
1473	return ret;
1474}
1475
1476static int ocfs2_write_begin_inline(struct address_space *mapping,
1477				    struct inode *inode,
1478				    struct ocfs2_write_ctxt *wc)
1479{
1480	int ret;
1481	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1482	struct page *page;
1483	handle_t *handle;
1484	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1485
1486	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1487	if (IS_ERR(handle)) {
1488		ret = PTR_ERR(handle);
1489		mlog_errno(ret);
1490		goto out;
1491	}
1492
1493	page = find_or_create_page(mapping, 0, GFP_NOFS);
1494	if (!page) {
1495		ocfs2_commit_trans(osb, handle);
1496		ret = -ENOMEM;
1497		mlog_errno(ret);
1498		goto out;
1499	}
1500	/*
1501	 * If we don't set w_num_pages then this page won't get unlocked
1502	 * and freed on cleanup of the write context.
1503	 */
1504	wc->w_pages[0] = wc->w_target_page = page;
1505	wc->w_num_pages = 1;
1506
1507	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1508				      OCFS2_JOURNAL_ACCESS_WRITE);
1509	if (ret) {
1510		ocfs2_commit_trans(osb, handle);
1511
1512		mlog_errno(ret);
1513		goto out;
1514	}
1515
1516	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1517		ocfs2_set_inode_data_inline(inode, di);
1518
1519	if (!PageUptodate(page)) {
1520		ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1521		if (ret) {
1522			ocfs2_commit_trans(osb, handle);
1523
1524			goto out;
1525		}
1526	}
1527
1528	wc->w_handle = handle;
1529out:
1530	return ret;
1531}
1532
1533int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1534{
1535	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1536
1537	if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1538		return 1;
1539	return 0;
1540}
1541
1542static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1543					  struct inode *inode, loff_t pos,
1544					  unsigned len, struct page *mmap_page,
1545					  struct ocfs2_write_ctxt *wc)
1546{
1547	int ret, written = 0;
1548	loff_t end = pos + len;
1549	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1550	struct ocfs2_dinode *di = NULL;
1551
1552	trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1553					     len, (unsigned long long)pos,
1554					     oi->ip_dyn_features);
1555
1556	/*
1557	 * Handle inodes which already have inline data 1st.
1558	 */
1559	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1560		if (mmap_page == NULL &&
1561		    ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1562			goto do_inline_write;
1563
1564		/*
1565		 * The write won't fit - we have to give this inode an
1566		 * inline extent list now.
1567		 */
1568		ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1569		if (ret)
1570			mlog_errno(ret);
1571		goto out;
1572	}
1573
1574	/*
1575	 * Check whether the inode can accept inline data.
1576	 */
1577	if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1578		return 0;
1579
1580	/*
1581	 * Check whether the write can fit.
1582	 */
1583	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1584	if (mmap_page ||
1585	    end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1586		return 0;
1587
1588do_inline_write:
1589	ret = ocfs2_write_begin_inline(mapping, inode, wc);
1590	if (ret) {
1591		mlog_errno(ret);
1592		goto out;
1593	}
1594
1595	/*
1596	 * This signals to the caller that the data can be written
1597	 * inline.
1598	 */
1599	written = 1;
1600out:
1601	return written ? written : ret;
1602}
1603
1604/*
1605 * This function only does anything for file systems which can't
1606 * handle sparse files.
1607 *
1608 * What we want to do here is fill in any hole between the current end
1609 * of allocation and the end of our write. That way the rest of the
1610 * write path can treat it as an non-allocating write, which has no
1611 * special case code for sparse/nonsparse files.
1612 */
1613static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1614					struct buffer_head *di_bh,
1615					loff_t pos, unsigned len,
1616					struct ocfs2_write_ctxt *wc)
1617{
1618	int ret;
1619	loff_t newsize = pos + len;
1620
1621	BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1622
1623	if (newsize <= i_size_read(inode))
1624		return 0;
1625
1626	ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1627	if (ret)
1628		mlog_errno(ret);
1629
1630	/* There is no wc if this is call from direct. */
1631	if (wc)
1632		wc->w_first_new_cpos =
1633			ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1634
1635	return ret;
1636}
1637
1638static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1639			   loff_t pos)
1640{
1641	int ret = 0;
1642
1643	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1644	if (pos > i_size_read(inode))
1645		ret = ocfs2_zero_extend(inode, di_bh, pos);
1646
1647	return ret;
1648}
1649
1650int ocfs2_write_begin_nolock(struct address_space *mapping,
1651			     loff_t pos, unsigned len, ocfs2_write_type_t type,
1652			     struct page **pagep, void **fsdata,
1653			     struct buffer_head *di_bh, struct page *mmap_page)
1654{
1655	int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1656	unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1657	struct ocfs2_write_ctxt *wc;
1658	struct inode *inode = mapping->host;
1659	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1660	struct ocfs2_dinode *di;
1661	struct ocfs2_alloc_context *data_ac = NULL;
1662	struct ocfs2_alloc_context *meta_ac = NULL;
1663	handle_t *handle;
1664	struct ocfs2_extent_tree et;
1665	int try_free = 1, ret1;
1666
1667try_again:
1668	ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, type, di_bh);
1669	if (ret) {
1670		mlog_errno(ret);
1671		return ret;
1672	}
1673
1674	if (ocfs2_supports_inline_data(osb)) {
1675		ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1676						     mmap_page, wc);
1677		if (ret == 1) {
1678			ret = 0;
1679			goto success;
1680		}
1681		if (ret < 0) {
1682			mlog_errno(ret);
1683			goto out;
1684		}
1685	}
1686
1687	/* Direct io change i_size late, should not zero tail here. */
1688	if (type != OCFS2_WRITE_DIRECT) {
1689		if (ocfs2_sparse_alloc(osb))
1690			ret = ocfs2_zero_tail(inode, di_bh, pos);
1691		else
1692			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
1693							   len, wc);
1694		if (ret) {
1695			mlog_errno(ret);
1696			goto out;
1697		}
1698	}
1699
1700	ret = ocfs2_check_range_for_refcount(inode, pos, len);
1701	if (ret < 0) {
1702		mlog_errno(ret);
1703		goto out;
1704	} else if (ret == 1) {
1705		clusters_need = wc->w_clen;
1706		ret = ocfs2_refcount_cow(inode, di_bh,
1707					 wc->w_cpos, wc->w_clen, UINT_MAX);
1708		if (ret) {
1709			mlog_errno(ret);
1710			goto out;
1711		}
1712	}
1713
1714	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1715					&extents_to_split);
1716	if (ret) {
1717		mlog_errno(ret);
1718		goto out;
1719	}
1720	clusters_need += clusters_to_alloc;
1721
1722	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1723
1724	trace_ocfs2_write_begin_nolock(
1725			(unsigned long long)OCFS2_I(inode)->ip_blkno,
1726			(long long)i_size_read(inode),
1727			le32_to_cpu(di->i_clusters),
1728			pos, len, type, mmap_page,
1729			clusters_to_alloc, extents_to_split);
1730
1731	/*
1732	 * We set w_target_from, w_target_to here so that
1733	 * ocfs2_write_end() knows which range in the target page to
1734	 * write out. An allocation requires that we write the entire
1735	 * cluster range.
1736	 */
1737	if (clusters_to_alloc || extents_to_split) {
1738		/*
1739		 * XXX: We are stretching the limits of
1740		 * ocfs2_lock_allocators(). It greatly over-estimates
1741		 * the work to be done.
1742		 */
1743		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1744					      wc->w_di_bh);
1745		ret = ocfs2_lock_allocators(inode, &et,
1746					    clusters_to_alloc, extents_to_split,
1747					    &data_ac, &meta_ac);
1748		if (ret) {
1749			mlog_errno(ret);
1750			goto out;
1751		}
1752
1753		if (data_ac)
1754			data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1755
1756		credits = ocfs2_calc_extend_credits(inode->i_sb,
1757						    &di->id2.i_list);
1758	} else if (type == OCFS2_WRITE_DIRECT)
1759		/* direct write needs not to start trans if no extents alloc. */
1760		goto success;
1761
1762	/*
1763	 * We have to zero sparse allocated clusters, unwritten extent clusters,
1764	 * and non-sparse clusters we just extended.  For non-sparse writes,
1765	 * we know zeros will only be needed in the first and/or last cluster.
1766	 */
1767	if (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1768			   wc->w_desc[wc->w_clen - 1].c_needs_zero))
1769		cluster_of_pages = 1;
1770	else
1771		cluster_of_pages = 0;
1772
1773	ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1774
1775	handle = ocfs2_start_trans(osb, credits);
1776	if (IS_ERR(handle)) {
1777		ret = PTR_ERR(handle);
1778		mlog_errno(ret);
1779		goto out;
1780	}
1781
1782	wc->w_handle = handle;
1783
1784	if (clusters_to_alloc) {
1785		ret = dquot_alloc_space_nodirty(inode,
1786			ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1787		if (ret)
1788			goto out_commit;
1789	}
1790
1791	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1792				      OCFS2_JOURNAL_ACCESS_WRITE);
1793	if (ret) {
1794		mlog_errno(ret);
1795		goto out_quota;
1796	}
1797
1798	/*
1799	 * Fill our page array first. That way we've grabbed enough so
1800	 * that we can zero and flush if we error after adding the
1801	 * extent.
1802	 */
1803	ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
1804					 cluster_of_pages, mmap_page);
1805	if (ret && ret != -EAGAIN) {
1806		mlog_errno(ret);
1807		goto out_quota;
1808	}
 
 
 
 
 
 
 
 
1809
1810	/*
1811	 * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock
1812	 * the target page. In this case, we exit with no error and no target
1813	 * page. This will trigger the caller, page_mkwrite(), to re-try
1814	 * the operation.
1815	 */
1816	if (ret == -EAGAIN) {
1817		BUG_ON(wc->w_target_page);
1818		ret = 0;
1819		goto out_quota;
1820	}
1821
1822	ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1823					  len);
1824	if (ret) {
1825		mlog_errno(ret);
1826		goto out_quota;
1827	}
1828
1829	if (data_ac)
1830		ocfs2_free_alloc_context(data_ac);
1831	if (meta_ac)
1832		ocfs2_free_alloc_context(meta_ac);
1833
1834success:
1835	if (pagep)
1836		*pagep = wc->w_target_page;
1837	*fsdata = wc;
1838	return 0;
1839out_quota:
1840	if (clusters_to_alloc)
1841		dquot_free_space(inode,
1842			  ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1843out_commit:
1844	ocfs2_commit_trans(osb, handle);
1845
1846out:
1847	/*
1848	 * The mmapped page won't be unlocked in ocfs2_free_write_ctxt(),
1849	 * even in case of error here like ENOSPC and ENOMEM. So, we need
1850	 * to unlock the target page manually to prevent deadlocks when
1851	 * retrying again on ENOSPC, or when returning non-VM_FAULT_LOCKED
1852	 * to VM code.
1853	 */
1854	if (wc->w_target_locked)
1855		unlock_page(mmap_page);
1856
1857	ocfs2_free_write_ctxt(inode, wc);
1858
1859	if (data_ac) {
1860		ocfs2_free_alloc_context(data_ac);
1861		data_ac = NULL;
1862	}
1863	if (meta_ac) {
1864		ocfs2_free_alloc_context(meta_ac);
1865		meta_ac = NULL;
1866	}
1867
1868	if (ret == -ENOSPC && try_free) {
1869		/*
1870		 * Try to free some truncate log so that we can have enough
1871		 * clusters to allocate.
1872		 */
1873		try_free = 0;
1874
1875		ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1876		if (ret1 == 1)
1877			goto try_again;
1878
1879		if (ret1 < 0)
1880			mlog_errno(ret1);
1881	}
1882
1883	return ret;
1884}
1885
1886static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1887			     loff_t pos, unsigned len, unsigned flags,
1888			     struct page **pagep, void **fsdata)
1889{
1890	int ret;
1891	struct buffer_head *di_bh = NULL;
1892	struct inode *inode = mapping->host;
1893
1894	ret = ocfs2_inode_lock(inode, &di_bh, 1);
1895	if (ret) {
1896		mlog_errno(ret);
1897		return ret;
1898	}
1899
1900	/*
1901	 * Take alloc sem here to prevent concurrent lookups. That way
1902	 * the mapping, zeroing and tree manipulation within
1903	 * ocfs2_write() will be safe against ->readpage(). This
1904	 * should also serve to lock out allocation from a shared
1905	 * writeable region.
1906	 */
1907	down_write(&OCFS2_I(inode)->ip_alloc_sem);
1908
1909	ret = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_BUFFER,
1910				       pagep, fsdata, di_bh, NULL);
1911	if (ret) {
1912		mlog_errno(ret);
1913		goto out_fail;
1914	}
1915
1916	brelse(di_bh);
1917
1918	return 0;
1919
1920out_fail:
1921	up_write(&OCFS2_I(inode)->ip_alloc_sem);
1922
1923	brelse(di_bh);
1924	ocfs2_inode_unlock(inode, 1);
1925
1926	return ret;
1927}
1928
1929static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1930				   unsigned len, unsigned *copied,
1931				   struct ocfs2_dinode *di,
1932				   struct ocfs2_write_ctxt *wc)
1933{
1934	void *kaddr;
1935
1936	if (unlikely(*copied < len)) {
1937		if (!PageUptodate(wc->w_target_page)) {
1938			*copied = 0;
1939			return;
1940		}
1941	}
1942
1943	kaddr = kmap_atomic(wc->w_target_page);
1944	memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1945	kunmap_atomic(kaddr);
1946
1947	trace_ocfs2_write_end_inline(
1948	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1949	     (unsigned long long)pos, *copied,
1950	     le16_to_cpu(di->id2.i_data.id_count),
1951	     le16_to_cpu(di->i_dyn_features));
1952}
1953
1954int ocfs2_write_end_nolock(struct address_space *mapping,
1955			   loff_t pos, unsigned len, unsigned copied, void *fsdata)
1956{
1957	int i, ret;
1958	unsigned from, to, start = pos & (PAGE_SIZE - 1);
1959	struct inode *inode = mapping->host;
1960	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1961	struct ocfs2_write_ctxt *wc = fsdata;
1962	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1963	handle_t *handle = wc->w_handle;
1964	struct page *tmppage;
1965
1966	BUG_ON(!list_empty(&wc->w_unwritten_list));
1967
1968	if (handle) {
1969		ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode),
1970				wc->w_di_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1971		if (ret) {
1972			copied = ret;
1973			mlog_errno(ret);
1974			goto out;
1975		}
1976	}
1977
1978	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1979		ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1980		goto out_write_size;
1981	}
1982
1983	if (unlikely(copied < len) && wc->w_target_page) {
 
 
1984		if (!PageUptodate(wc->w_target_page))
1985			copied = 0;
1986
1987		ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1988				       start+len);
 
 
 
 
 
 
 
 
 
 
 
 
 
1989	}
1990	if (wc->w_target_page)
1991		flush_dcache_page(wc->w_target_page);
1992
1993	for(i = 0; i < wc->w_num_pages; i++) {
1994		tmppage = wc->w_pages[i];
1995
1996		/* This is the direct io target page. */
1997		if (tmppage == NULL)
1998			continue;
1999
2000		if (tmppage == wc->w_target_page) {
2001			from = wc->w_target_from;
2002			to = wc->w_target_to;
2003
2004			BUG_ON(from > PAGE_SIZE ||
2005			       to > PAGE_SIZE ||
2006			       to < from);
2007		} else {
2008			/*
2009			 * Pages adjacent to the target (if any) imply
2010			 * a hole-filling write in which case we want
2011			 * to flush their entire range.
2012			 */
2013			from = 0;
2014			to = PAGE_SIZE;
2015		}
2016
2017		if (page_has_buffers(tmppage)) {
2018			if (handle && ocfs2_should_order_data(inode)) {
2019				loff_t start_byte =
2020					((loff_t)tmppage->index << PAGE_SHIFT) +
2021					from;
2022				loff_t length = to - from;
2023				ocfs2_jbd2_inode_add_write(handle, inode,
2024							   start_byte, length);
2025			}
2026			block_commit_write(tmppage, from, to);
2027		}
2028	}
2029
2030out_write_size:
2031	/* Direct io do not update i_size here. */
2032	if (wc->w_type != OCFS2_WRITE_DIRECT) {
2033		pos += copied;
2034		if (pos > i_size_read(inode)) {
2035			i_size_write(inode, pos);
2036			mark_inode_dirty(inode);
2037		}
2038		inode->i_blocks = ocfs2_inode_sector_count(inode);
2039		di->i_size = cpu_to_le64((u64)i_size_read(inode));
2040		inode->i_mtime = inode->i_ctime = current_time(inode);
2041		di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
2042		di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
2043		if (handle)
2044			ocfs2_update_inode_fsync_trans(handle, inode, 1);
2045	}
2046	if (handle)
2047		ocfs2_journal_dirty(handle, wc->w_di_bh);
2048
2049out:
2050	/* unlock pages before dealloc since it needs acquiring j_trans_barrier
2051	 * lock, or it will cause a deadlock since journal commit threads holds
2052	 * this lock and will ask for the page lock when flushing the data.
2053	 * put it here to preserve the unlock order.
2054	 */
2055	ocfs2_unlock_pages(wc);
2056
2057	if (handle)
2058		ocfs2_commit_trans(osb, handle);
2059
2060	ocfs2_run_deallocs(osb, &wc->w_dealloc);
2061
2062	brelse(wc->w_di_bh);
2063	kfree(wc);
2064
2065	return copied;
2066}
2067
2068static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2069			   loff_t pos, unsigned len, unsigned copied,
2070			   struct page *page, void *fsdata)
2071{
2072	int ret;
2073	struct inode *inode = mapping->host;
2074
2075	ret = ocfs2_write_end_nolock(mapping, pos, len, copied, fsdata);
2076
2077	up_write(&OCFS2_I(inode)->ip_alloc_sem);
2078	ocfs2_inode_unlock(inode, 1);
2079
2080	return ret;
2081}
2082
2083struct ocfs2_dio_write_ctxt {
2084	struct list_head	dw_zero_list;
2085	unsigned		dw_zero_count;
2086	int			dw_orphaned;
2087	pid_t			dw_writer_pid;
2088};
2089
2090static struct ocfs2_dio_write_ctxt *
2091ocfs2_dio_alloc_write_ctx(struct buffer_head *bh, int *alloc)
2092{
2093	struct ocfs2_dio_write_ctxt *dwc = NULL;
2094
2095	if (bh->b_private)
2096		return bh->b_private;
2097
2098	dwc = kmalloc(sizeof(struct ocfs2_dio_write_ctxt), GFP_NOFS);
2099	if (dwc == NULL)
2100		return NULL;
2101	INIT_LIST_HEAD(&dwc->dw_zero_list);
2102	dwc->dw_zero_count = 0;
2103	dwc->dw_orphaned = 0;
2104	dwc->dw_writer_pid = task_pid_nr(current);
2105	bh->b_private = dwc;
2106	*alloc = 1;
2107
2108	return dwc;
2109}
2110
2111static void ocfs2_dio_free_write_ctx(struct inode *inode,
2112				     struct ocfs2_dio_write_ctxt *dwc)
2113{
2114	ocfs2_free_unwritten_list(inode, &dwc->dw_zero_list);
2115	kfree(dwc);
2116}
2117
2118/*
2119 * TODO: Make this into a generic get_blocks function.
2120 *
2121 * From do_direct_io in direct-io.c:
2122 *  "So what we do is to permit the ->get_blocks function to populate
2123 *   bh.b_size with the size of IO which is permitted at this offset and
2124 *   this i_blkbits."
2125 *
2126 * This function is called directly from get_more_blocks in direct-io.c.
2127 *
2128 * called like this: dio->get_blocks(dio->inode, fs_startblk,
2129 * 					fs_count, map_bh, dio->rw == WRITE);
2130 */
2131static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock,
2132			       struct buffer_head *bh_result, int create)
2133{
2134	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2135	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2136	struct ocfs2_write_ctxt *wc;
2137	struct ocfs2_write_cluster_desc *desc = NULL;
2138	struct ocfs2_dio_write_ctxt *dwc = NULL;
2139	struct buffer_head *di_bh = NULL;
2140	u64 p_blkno;
2141	unsigned int i_blkbits = inode->i_sb->s_blocksize_bits;
2142	loff_t pos = iblock << i_blkbits;
2143	sector_t endblk = (i_size_read(inode) - 1) >> i_blkbits;
2144	unsigned len, total_len = bh_result->b_size;
2145	int ret = 0, first_get_block = 0;
2146
2147	len = osb->s_clustersize - (pos & (osb->s_clustersize - 1));
2148	len = min(total_len, len);
2149
2150	/*
2151	 * bh_result->b_size is count in get_more_blocks according to write
2152	 * "pos" and "end", we need map twice to return different buffer state:
2153	 * 1. area in file size, not set NEW;
2154	 * 2. area out file size, set  NEW.
2155	 *
2156	 *		   iblock    endblk
2157	 * |--------|---------|---------|---------
2158	 * |<-------area in file------->|
2159	 */
2160
2161	if ((iblock <= endblk) &&
2162	    ((iblock + ((len - 1) >> i_blkbits)) > endblk))
2163		len = (endblk - iblock + 1) << i_blkbits;
2164
2165	mlog(0, "get block of %lu at %llu:%u req %u\n",
2166			inode->i_ino, pos, len, total_len);
2167
2168	/*
2169	 * Because we need to change file size in ocfs2_dio_end_io_write(), or
2170	 * we may need to add it to orphan dir. So can not fall to fast path
2171	 * while file size will be changed.
2172	 */
2173	if (pos + total_len <= i_size_read(inode)) {
2174
2175		/* This is the fast path for re-write. */
2176		ret = ocfs2_lock_get_block(inode, iblock, bh_result, create);
2177		if (buffer_mapped(bh_result) &&
2178		    !buffer_new(bh_result) &&
2179		    ret == 0)
2180			goto out;
2181
2182		/* Clear state set by ocfs2_get_block. */
2183		bh_result->b_state = 0;
2184	}
2185
2186	dwc = ocfs2_dio_alloc_write_ctx(bh_result, &first_get_block);
2187	if (unlikely(dwc == NULL)) {
2188		ret = -ENOMEM;
2189		mlog_errno(ret);
2190		goto out;
2191	}
2192
2193	if (ocfs2_clusters_for_bytes(inode->i_sb, pos + total_len) >
2194	    ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode)) &&
2195	    !dwc->dw_orphaned) {
2196		/*
2197		 * when we are going to alloc extents beyond file size, add the
2198		 * inode to orphan dir, so we can recall those spaces when
2199		 * system crashed during write.
2200		 */
2201		ret = ocfs2_add_inode_to_orphan(osb, inode);
2202		if (ret < 0) {
2203			mlog_errno(ret);
2204			goto out;
2205		}
2206		dwc->dw_orphaned = 1;
2207	}
2208
2209	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2210	if (ret) {
2211		mlog_errno(ret);
2212		goto out;
2213	}
2214
2215	down_write(&oi->ip_alloc_sem);
2216
2217	if (first_get_block) {
2218		if (ocfs2_sparse_alloc(osb))
2219			ret = ocfs2_zero_tail(inode, di_bh, pos);
2220		else
2221			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
2222							   total_len, NULL);
2223		if (ret < 0) {
2224			mlog_errno(ret);
2225			goto unlock;
2226		}
2227	}
2228
2229	ret = ocfs2_write_begin_nolock(inode->i_mapping, pos, len,
2230				       OCFS2_WRITE_DIRECT, NULL,
2231				       (void **)&wc, di_bh, NULL);
2232	if (ret) {
2233		mlog_errno(ret);
2234		goto unlock;
2235	}
2236
2237	desc = &wc->w_desc[0];
2238
2239	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, desc->c_phys);
2240	BUG_ON(p_blkno == 0);
2241	p_blkno += iblock & (u64)(ocfs2_clusters_to_blocks(inode->i_sb, 1) - 1);
2242
2243	map_bh(bh_result, inode->i_sb, p_blkno);
2244	bh_result->b_size = len;
2245	if (desc->c_needs_zero)
2246		set_buffer_new(bh_result);
2247
2248	if (iblock > endblk)
2249		set_buffer_new(bh_result);
2250
2251	/* May sleep in end_io. It should not happen in a irq context. So defer
2252	 * it to dio work queue. */
2253	set_buffer_defer_completion(bh_result);
2254
2255	if (!list_empty(&wc->w_unwritten_list)) {
2256		struct ocfs2_unwritten_extent *ue = NULL;
2257
2258		ue = list_first_entry(&wc->w_unwritten_list,
2259				      struct ocfs2_unwritten_extent,
2260				      ue_node);
2261		BUG_ON(ue->ue_cpos != desc->c_cpos);
2262		/* The physical address may be 0, fill it. */
2263		ue->ue_phys = desc->c_phys;
2264
2265		list_splice_tail_init(&wc->w_unwritten_list, &dwc->dw_zero_list);
2266		dwc->dw_zero_count += wc->w_unwritten_count;
2267	}
2268
2269	ret = ocfs2_write_end_nolock(inode->i_mapping, pos, len, len, wc);
2270	BUG_ON(ret != len);
2271	ret = 0;
2272unlock:
2273	up_write(&oi->ip_alloc_sem);
2274	ocfs2_inode_unlock(inode, 1);
2275	brelse(di_bh);
2276out:
2277	if (ret < 0)
2278		ret = -EIO;
2279	return ret;
2280}
2281
2282static int ocfs2_dio_end_io_write(struct inode *inode,
2283				  struct ocfs2_dio_write_ctxt *dwc,
2284				  loff_t offset,
2285				  ssize_t bytes)
2286{
2287	struct ocfs2_cached_dealloc_ctxt dealloc;
2288	struct ocfs2_extent_tree et;
2289	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2290	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2291	struct ocfs2_unwritten_extent *ue = NULL;
2292	struct buffer_head *di_bh = NULL;
2293	struct ocfs2_dinode *di;
2294	struct ocfs2_alloc_context *data_ac = NULL;
2295	struct ocfs2_alloc_context *meta_ac = NULL;
2296	handle_t *handle = NULL;
2297	loff_t end = offset + bytes;
2298	int ret = 0, credits = 0, locked = 0;
2299
2300	ocfs2_init_dealloc_ctxt(&dealloc);
2301
2302	/* We do clear unwritten, delete orphan, change i_size here. If neither
2303	 * of these happen, we can skip all this. */
2304	if (list_empty(&dwc->dw_zero_list) &&
2305	    end <= i_size_read(inode) &&
2306	    !dwc->dw_orphaned)
2307		goto out;
2308
2309	/* ocfs2_file_write_iter will get i_mutex, so we need not lock if we
2310	 * are in that context. */
2311	if (dwc->dw_writer_pid != task_pid_nr(current)) {
2312		inode_lock(inode);
2313		locked = 1;
2314	}
2315
2316	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2317	if (ret < 0) {
2318		mlog_errno(ret);
2319		goto out;
2320	}
2321
2322	down_write(&oi->ip_alloc_sem);
2323
2324	/* Delete orphan before acquire i_mutex. */
2325	if (dwc->dw_orphaned) {
2326		BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
2327
2328		end = end > i_size_read(inode) ? end : 0;
2329
2330		ret = ocfs2_del_inode_from_orphan(osb, inode, di_bh,
2331				!!end, end);
2332		if (ret < 0)
2333			mlog_errno(ret);
2334	}
2335
2336	di = (struct ocfs2_dinode *)di_bh->b_data;
2337
2338	ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
2339
2340	/* Attach dealloc with extent tree in case that we may reuse extents
2341	 * which are already unlinked from current extent tree due to extent
2342	 * rotation and merging.
2343	 */
2344	et.et_dealloc = &dealloc;
2345
2346	ret = ocfs2_lock_allocators(inode, &et, 0, dwc->dw_zero_count*2,
2347				    &data_ac, &meta_ac);
2348	if (ret) {
2349		mlog_errno(ret);
2350		goto unlock;
2351	}
2352
2353	credits = ocfs2_calc_extend_credits(inode->i_sb, &di->id2.i_list);
2354
2355	handle = ocfs2_start_trans(osb, credits);
2356	if (IS_ERR(handle)) {
2357		ret = PTR_ERR(handle);
2358		mlog_errno(ret);
2359		goto unlock;
2360	}
2361	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
2362				      OCFS2_JOURNAL_ACCESS_WRITE);
2363	if (ret) {
2364		mlog_errno(ret);
2365		goto commit;
2366	}
2367
2368	list_for_each_entry(ue, &dwc->dw_zero_list, ue_node) {
 
 
 
 
 
2369		ret = ocfs2_mark_extent_written(inode, &et, handle,
2370						ue->ue_cpos, 1,
2371						ue->ue_phys,
2372						meta_ac, &dealloc);
2373		if (ret < 0) {
2374			mlog_errno(ret);
2375			break;
2376		}
2377	}
2378
2379	if (end > i_size_read(inode)) {
2380		ret = ocfs2_set_inode_size(handle, inode, di_bh, end);
2381		if (ret < 0)
2382			mlog_errno(ret);
2383	}
2384commit:
2385	ocfs2_commit_trans(osb, handle);
2386unlock:
2387	up_write(&oi->ip_alloc_sem);
2388	ocfs2_inode_unlock(inode, 1);
2389	brelse(di_bh);
2390out:
2391	if (data_ac)
2392		ocfs2_free_alloc_context(data_ac);
2393	if (meta_ac)
2394		ocfs2_free_alloc_context(meta_ac);
2395	ocfs2_run_deallocs(osb, &dealloc);
2396	if (locked)
2397		inode_unlock(inode);
2398	ocfs2_dio_free_write_ctx(inode, dwc);
2399
2400	return ret;
2401}
2402
2403/*
2404 * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
2405 * particularly interested in the aio/dio case.  We use the rw_lock DLM lock
2406 * to protect io on one node from truncation on another.
2407 */
2408static int ocfs2_dio_end_io(struct kiocb *iocb,
2409			    loff_t offset,
2410			    ssize_t bytes,
2411			    void *private)
2412{
2413	struct inode *inode = file_inode(iocb->ki_filp);
2414	int level;
2415	int ret = 0;
2416
2417	/* this io's submitter should not have unlocked this before we could */
2418	BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
2419
2420	if (bytes <= 0)
2421		mlog_ratelimited(ML_ERROR, "Direct IO failed, bytes = %lld",
2422				 (long long)bytes);
2423	if (private) {
2424		if (bytes > 0)
2425			ret = ocfs2_dio_end_io_write(inode, private, offset,
2426						     bytes);
2427		else
2428			ocfs2_dio_free_write_ctx(inode, private);
2429	}
2430
2431	ocfs2_iocb_clear_rw_locked(iocb);
2432
2433	level = ocfs2_iocb_rw_locked_level(iocb);
2434	ocfs2_rw_unlock(inode, level);
2435	return ret;
2436}
2437
2438static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
2439{
2440	struct file *file = iocb->ki_filp;
2441	struct inode *inode = file->f_mapping->host;
2442	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2443	get_block_t *get_block;
2444
2445	/*
2446	 * Fallback to buffered I/O if we see an inode without
2447	 * extents.
2448	 */
2449	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
2450		return 0;
2451
2452	/* Fallback to buffered I/O if we do not support append dio. */
2453	if (iocb->ki_pos + iter->count > i_size_read(inode) &&
2454	    !ocfs2_supports_append_dio(osb))
2455		return 0;
2456
2457	if (iov_iter_rw(iter) == READ)
2458		get_block = ocfs2_lock_get_block;
2459	else
2460		get_block = ocfs2_dio_wr_get_block;
2461
2462	return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
2463				    iter, get_block,
2464				    ocfs2_dio_end_io, NULL, 0);
2465}
2466
2467const struct address_space_operations ocfs2_aops = {
2468	.readpage		= ocfs2_readpage,
 
2469	.readahead		= ocfs2_readahead,
2470	.writepage		= ocfs2_writepage,
2471	.write_begin		= ocfs2_write_begin,
2472	.write_end		= ocfs2_write_end,
2473	.bmap			= ocfs2_bmap,
2474	.direct_IO		= ocfs2_direct_IO,
2475	.invalidatepage		= block_invalidatepage,
2476	.releasepage		= ocfs2_releasepage,
2477	.migratepage		= buffer_migrate_page,
2478	.is_partially_uptodate	= block_is_partially_uptodate,
2479	.error_remove_page	= generic_error_remove_page,
2480};