1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
 
   3 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   4 */
   5
   6#include <linux/fs.h>
   7#include <linux/slab.h>
   8#include <linux/highmem.h>
   9#include <linux/pagemap.h>
  10#include <asm/byteorder.h>
  11#include <linux/swap.h>
 
  12#include <linux/mpage.h>
  13#include <linux/quotaops.h>
  14#include <linux/blkdev.h>
  15#include <linux/uio.h>
  16#include <linux/mm.h>
  17
  18#include <cluster/masklog.h>
  19
  20#include "ocfs2.h"
  21
  22#include "alloc.h"
  23#include "aops.h"
  24#include "dlmglue.h"
  25#include "extent_map.h"
  26#include "file.h"
  27#include "inode.h"
  28#include "journal.h"
  29#include "suballoc.h"
  30#include "super.h"
  31#include "symlink.h"
  32#include "refcounttree.h"
  33#include "ocfs2_trace.h"
  34
  35#include "buffer_head_io.h"
  36#include "dir.h"
  37#include "namei.h"
  38#include "sysfile.h"
  39
  40static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
  41				   struct buffer_head *bh_result, int create)
  42{
  43	int err = -EIO;
  44	int status;
  45	struct ocfs2_dinode *fe = NULL;
  46	struct buffer_head *bh = NULL;
  47	struct buffer_head *buffer_cache_bh = NULL;
  48	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  49	void *kaddr;
  50
  51	trace_ocfs2_symlink_get_block(
  52			(unsigned long long)OCFS2_I(inode)->ip_blkno,
  53			(unsigned long long)iblock, bh_result, create);
  54
  55	BUG_ON(ocfs2_inode_is_fast_symlink(inode));
  56
  57	if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
  58		mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
  59		     (unsigned long long)iblock);
  60		goto bail;
  61	}
  62
  63	status = ocfs2_read_inode_block(inode, &bh);
  64	if (status < 0) {
  65		mlog_errno(status);
  66		goto bail;
  67	}
  68	fe = (struct ocfs2_dinode *) bh->b_data;
  69
  70	if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
  71						    le32_to_cpu(fe->i_clusters))) {
  72		err = -ENOMEM;
  73		mlog(ML_ERROR, "block offset is outside the allocated size: "
  74		     "%llu\n", (unsigned long long)iblock);
  75		goto bail;
  76	}
  77
  78	/* We don't use the page cache to create symlink data, so if
  79	 * need be, copy it over from the buffer cache. */
  80	if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
  81		u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
  82			    iblock;
  83		buffer_cache_bh = sb_getblk(osb->sb, blkno);
  84		if (!buffer_cache_bh) {
  85			err = -ENOMEM;
  86			mlog(ML_ERROR, "couldn't getblock for symlink!\n");
  87			goto bail;
  88		}
  89
  90		/* we haven't locked out transactions, so a commit
  91		 * could've happened. Since we've got a reference on
  92		 * the bh, even if it commits while we're doing the
  93		 * copy, the data is still good. */
  94		if (buffer_jbd(buffer_cache_bh)
  95		    && ocfs2_inode_is_new(inode)) {
  96			kaddr = kmap_atomic(bh_result->b_page);
  97			if (!kaddr) {
  98				mlog(ML_ERROR, "couldn't kmap!\n");
  99				goto bail;
 100			}
 101			memcpy(kaddr + (bh_result->b_size * iblock),
 102			       buffer_cache_bh->b_data,
 103			       bh_result->b_size);
 104			kunmap_atomic(kaddr);
 105			set_buffer_uptodate(bh_result);
 106		}
 107		brelse(buffer_cache_bh);
 108	}
 109
 110	map_bh(bh_result, inode->i_sb,
 111	       le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
 112
 113	err = 0;
 114
 115bail:
 116	brelse(bh);
 117
 118	return err;
 119}
 120
 121static int ocfs2_lock_get_block(struct inode *inode, sector_t iblock,
 122		    struct buffer_head *bh_result, int create)
 123{
 124	int ret = 0;
 125	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 126
 127	down_read(&oi->ip_alloc_sem);
 128	ret = ocfs2_get_block(inode, iblock, bh_result, create);
 129	up_read(&oi->ip_alloc_sem);
 130
 131	return ret;
 132}
 133
 134int ocfs2_get_block(struct inode *inode, sector_t iblock,
 135		    struct buffer_head *bh_result, int create)
 136{
 137	int err = 0;
 138	unsigned int ext_flags;
 139	u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
 140	u64 p_blkno, count, past_eof;
 141	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 142
 143	trace_ocfs2_get_block((unsigned long long)OCFS2_I(inode)->ip_blkno,
 144			      (unsigned long long)iblock, bh_result, create);
 145
 146	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
 147		mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
 148		     inode, inode->i_ino);
 149
 150	if (S_ISLNK(inode->i_mode)) {
 151		/* this always does I/O for some reason. */
 152		err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
 153		goto bail;
 154	}
 155
 156	err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
 157					  &ext_flags);
 158	if (err) {
 159		mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
 160		     "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
 161		     (unsigned long long)p_blkno);
 162		goto bail;
 163	}
 164
 165	if (max_blocks < count)
 166		count = max_blocks;
 167
 168	/*
 169	 * ocfs2 never allocates in this function - the only time we
 170	 * need to use BH_New is when we're extending i_size on a file
 171	 * system which doesn't support holes, in which case BH_New
 172	 * allows __block_write_begin() to zero.
 173	 *
 174	 * If we see this on a sparse file system, then a truncate has
 175	 * raced us and removed the cluster. In this case, we clear
 176	 * the buffers dirty and uptodate bits and let the buffer code
 177	 * ignore it as a hole.
 178	 */
 179	if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
 180		clear_buffer_dirty(bh_result);
 181		clear_buffer_uptodate(bh_result);
 182		goto bail;
 183	}
 184
 185	/* Treat the unwritten extent as a hole for zeroing purposes. */
 186	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 187		map_bh(bh_result, inode->i_sb, p_blkno);
 188
 189	bh_result->b_size = count << inode->i_blkbits;
 190
 191	if (!ocfs2_sparse_alloc(osb)) {
 192		if (p_blkno == 0) {
 193			err = -EIO;
 194			mlog(ML_ERROR,
 195			     "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
 196			     (unsigned long long)iblock,
 197			     (unsigned long long)p_blkno,
 198			     (unsigned long long)OCFS2_I(inode)->ip_blkno);
 199			mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
 200			dump_stack();
 201			goto bail;
 202		}
 203	}
 204
 205	past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
 206
 207	trace_ocfs2_get_block_end((unsigned long long)OCFS2_I(inode)->ip_blkno,
 208				  (unsigned long long)past_eof);
 209	if (create && (iblock >= past_eof))
 210		set_buffer_new(bh_result);
 211
 212bail:
 213	if (err < 0)
 214		err = -EIO;
 215
 216	return err;
 217}
 218
 219int ocfs2_read_inline_data(struct inode *inode, struct page *page,
 220			   struct buffer_head *di_bh)
 221{
 222	void *kaddr;
 223	loff_t size;
 224	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 225
 226	if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
 227		ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag\n",
 228			    (unsigned long long)OCFS2_I(inode)->ip_blkno);
 229		return -EROFS;
 230	}
 231
 232	size = i_size_read(inode);
 233
 234	if (size > PAGE_SIZE ||
 235	    size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
 236		ocfs2_error(inode->i_sb,
 237			    "Inode %llu has with inline data has bad size: %Lu\n",
 238			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
 239			    (unsigned long long)size);
 240		return -EROFS;
 241	}
 242
 243	kaddr = kmap_atomic(page);
 244	if (size)
 245		memcpy(kaddr, di->id2.i_data.id_data, size);
 246	/* Clear the remaining part of the page */
 247	memset(kaddr + size, 0, PAGE_SIZE - size);
 248	flush_dcache_page(page);
 249	kunmap_atomic(kaddr);
 250
 251	SetPageUptodate(page);
 252
 253	return 0;
 254}
 255
 256static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
 257{
 258	int ret;
 259	struct buffer_head *di_bh = NULL;
 260
 261	BUG_ON(!PageLocked(page));
 262	BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
 263
 264	ret = ocfs2_read_inode_block(inode, &di_bh);
 265	if (ret) {
 266		mlog_errno(ret);
 267		goto out;
 268	}
 269
 270	ret = ocfs2_read_inline_data(inode, page, di_bh);
 271out:
 272	unlock_page(page);
 273
 274	brelse(di_bh);
 275	return ret;
 276}
 277
 278static int ocfs2_read_folio(struct file *file, struct folio *folio)
 279{
 280	struct inode *inode = folio->mapping->host;
 281	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 282	loff_t start = folio_pos(folio);
 283	int ret, unlock = 1;
 284
 285	trace_ocfs2_readpage((unsigned long long)oi->ip_blkno, folio->index);
 
 286
 287	ret = ocfs2_inode_lock_with_page(inode, NULL, 0, &folio->page);
 288	if (ret != 0) {
 289		if (ret == AOP_TRUNCATED_PAGE)
 290			unlock = 0;
 291		mlog_errno(ret);
 292		goto out;
 293	}
 294
 295	if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
 296		/*
 297		 * Unlock the folio and cycle ip_alloc_sem so that we don't
 298		 * busyloop waiting for ip_alloc_sem to unlock
 299		 */
 300		ret = AOP_TRUNCATED_PAGE;
 301		folio_unlock(folio);
 302		unlock = 0;
 303		down_read(&oi->ip_alloc_sem);
 304		up_read(&oi->ip_alloc_sem);
 305		goto out_inode_unlock;
 306	}
 307
 308	/*
 309	 * i_size might have just been updated as we grabed the meta lock.  We
 310	 * might now be discovering a truncate that hit on another node.
 311	 * block_read_full_folio->get_block freaks out if it is asked to read
 312	 * beyond the end of a file, so we check here.  Callers
 313	 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
 314	 * and notice that the folio they just read isn't needed.
 315	 *
 316	 * XXX sys_readahead() seems to get that wrong?
 317	 */
 318	if (start >= i_size_read(inode)) {
 319		folio_zero_segment(folio, 0, folio_size(folio));
 320		folio_mark_uptodate(folio);
 321		ret = 0;
 322		goto out_alloc;
 323	}
 324
 325	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 326		ret = ocfs2_readpage_inline(inode, &folio->page);
 327	else
 328		ret = block_read_full_folio(folio, ocfs2_get_block);
 329	unlock = 0;
 330
 331out_alloc:
 332	up_read(&oi->ip_alloc_sem);
 333out_inode_unlock:
 334	ocfs2_inode_unlock(inode, 0);
 335out:
 336	if (unlock)
 337		folio_unlock(folio);
 338	return ret;
 339}
 340
 341/*
 342 * This is used only for read-ahead. Failures or difficult to handle
 343 * situations are safe to ignore.
 344 *
 345 * Right now, we don't bother with BH_Boundary - in-inode extent lists
 346 * are quite large (243 extents on 4k blocks), so most inodes don't
 347 * grow out to a tree. If need be, detecting boundary extents could
 348 * trivially be added in a future version of ocfs2_get_block().
 349 */
 350static void ocfs2_readahead(struct readahead_control *rac)
 
 351{
 352	int ret;
 353	struct inode *inode = rac->mapping->host;
 354	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 
 
 355
 356	/*
 357	 * Use the nonblocking flag for the dlm code to avoid page
 358	 * lock inversion, but don't bother with retrying.
 359	 */
 360	ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
 361	if (ret)
 362		return;
 363
 364	if (down_read_trylock(&oi->ip_alloc_sem) == 0)
 365		goto out_unlock;
 
 
 366
 367	/*
 368	 * Don't bother with inline-data. There isn't anything
 369	 * to read-ahead in that case anyway...
 370	 */
 371	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 372		goto out_up;
 373
 374	/*
 375	 * Check whether a remote node truncated this file - we just
 376	 * drop out in that case as it's not worth handling here.
 377	 */
 378	if (readahead_pos(rac) >= i_size_read(inode))
 379		goto out_up;
 
 
 380
 381	mpage_readahead(rac, ocfs2_get_block);
 382
 383out_up:
 384	up_read(&oi->ip_alloc_sem);
 385out_unlock:
 
 386	ocfs2_inode_unlock(inode, 0);
 
 
 387}
 388
 389/* Note: Because we don't support holes, our allocation has
 390 * already happened (allocation writes zeros to the file data)
 391 * so we don't have to worry about ordered writes in
 392 * ocfs2_writepages.
 393 *
 394 * ->writepages is called during the process of invalidating the page cache
 395 * during blocked lock processing.  It can't block on any cluster locks
 396 * to during block mapping.  It's relying on the fact that the block
 397 * mapping can't have disappeared under the dirty pages that it is
 398 * being asked to write back.
 399 */
 400static int ocfs2_writepages(struct address_space *mapping,
 401		struct writeback_control *wbc)
 402{
 403	return mpage_writepages(mapping, wbc, ocfs2_get_block);
 
 
 
 
 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	/*
 453	 * The swap code (ab-)uses ->bmap to get a block mapping and then
 454	 * bypasseѕ the file system for actual I/O.  We really can't allow
 455	 * that on refcounted inodes, so we have to skip out here.  And yes,
 456	 * 0 is the magic code for a bmap error..
 457	 */
 458	if (ocfs2_is_refcount_inode(inode))
 459		return 0;
 460
 461	/* We don't need to lock journal system files, since they aren't
 462	 * accessed concurrently from multiple nodes.
 463	 */
 464	if (!INODE_JOURNAL(inode)) {
 465		err = ocfs2_inode_lock(inode, NULL, 0);
 466		if (err) {
 467			if (err != -ENOENT)
 468				mlog_errno(err);
 469			goto bail;
 470		}
 471		down_read(&OCFS2_I(inode)->ip_alloc_sem);
 472	}
 473
 474	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
 475		err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
 476						  NULL);
 477
 478	if (!INODE_JOURNAL(inode)) {
 479		up_read(&OCFS2_I(inode)->ip_alloc_sem);
 480		ocfs2_inode_unlock(inode, 0);
 481	}
 482
 483	if (err) {
 484		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
 485		     (unsigned long long)block);
 486		mlog_errno(err);
 487		goto bail;
 488	}
 489
 490bail:
 491	status = err ? 0 : p_blkno;
 492
 493	return status;
 494}
 495
 496static bool ocfs2_release_folio(struct folio *folio, gfp_t wait)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 497{
 498	if (!folio_buffers(folio))
 499		return false;
 500	return try_to_free_buffers(folio);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 501}
 502
 503static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
 504					    u32 cpos,
 505					    unsigned int *start,
 506					    unsigned int *end)
 507{
 508	unsigned int cluster_start = 0, cluster_end = PAGE_SIZE;
 509
 510	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits)) {
 511		unsigned int cpp;
 512
 513		cpp = 1 << (PAGE_SHIFT - osb->s_clustersize_bits);
 514
 515		cluster_start = cpos % cpp;
 516		cluster_start = cluster_start << osb->s_clustersize_bits;
 517
 518		cluster_end = cluster_start + osb->s_clustersize;
 519	}
 520
 521	BUG_ON(cluster_start > PAGE_SIZE);
 522	BUG_ON(cluster_end > PAGE_SIZE);
 523
 524	if (start)
 525		*start = cluster_start;
 526	if (end)
 527		*end = cluster_end;
 528}
 529
 530/*
 531 * 'from' and 'to' are the region in the page to avoid zeroing.
 532 *
 533 * If pagesize > clustersize, this function will avoid zeroing outside
 534 * of the cluster boundary.
 535 *
 536 * from == to == 0 is code for "zero the entire cluster region"
 537 */
 538static void ocfs2_clear_page_regions(struct page *page,
 539				     struct ocfs2_super *osb, u32 cpos,
 540				     unsigned from, unsigned to)
 541{
 542	void *kaddr;
 543	unsigned int cluster_start, cluster_end;
 544
 545	ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
 546
 547	kaddr = kmap_atomic(page);
 548
 549	if (from || to) {
 550		if (from > cluster_start)
 551			memset(kaddr + cluster_start, 0, from - cluster_start);
 552		if (to < cluster_end)
 553			memset(kaddr + to, 0, cluster_end - to);
 554	} else {
 555		memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
 556	}
 557
 558	kunmap_atomic(kaddr);
 559}
 560
 561/*
 562 * Nonsparse file systems fully allocate before we get to the write
 563 * code. This prevents ocfs2_write() from tagging the write as an
 564 * allocating one, which means ocfs2_map_page_blocks() might try to
 565 * read-in the blocks at the tail of our file. Avoid reading them by
 566 * testing i_size against each block offset.
 567 */
 568static int ocfs2_should_read_blk(struct inode *inode, struct folio *folio,
 569				 unsigned int block_start)
 570{
 571	u64 offset = folio_pos(folio) + block_start;
 572
 573	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
 574		return 1;
 575
 576	if (i_size_read(inode) > offset)
 577		return 1;
 578
 579	return 0;
 580}
 581
 582/*
 583 * Some of this taken from __block_write_begin(). We already have our
 584 * mapping by now though, and the entire write will be allocating or
 585 * it won't, so not much need to use BH_New.
 586 *
 587 * This will also skip zeroing, which is handled externally.
 588 */
 589int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
 590			  struct inode *inode, unsigned int from,
 591			  unsigned int to, int new)
 592{
 593	struct folio *folio = page_folio(page);
 594	int ret = 0;
 595	struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
 596	unsigned int block_end, block_start;
 597	unsigned int bsize = i_blocksize(inode);
 598
 599	head = folio_buffers(folio);
 600	if (!head)
 601		head = create_empty_buffers(folio, bsize, 0);
 602
 
 603	for (bh = head, block_start = 0; bh != head || !block_start;
 604	     bh = bh->b_this_page, block_start += bsize) {
 605		block_end = block_start + bsize;
 606
 607		clear_buffer_new(bh);
 608
 609		/*
 610		 * Ignore blocks outside of our i/o range -
 611		 * they may belong to unallocated clusters.
 612		 */
 613		if (block_start >= to || block_end <= from) {
 614			if (folio_test_uptodate(folio))
 615				set_buffer_uptodate(bh);
 616			continue;
 617		}
 618
 619		/*
 620		 * For an allocating write with cluster size >= page
 621		 * size, we always write the entire page.
 622		 */
 623		if (new)
 624			set_buffer_new(bh);
 625
 626		if (!buffer_mapped(bh)) {
 627			map_bh(bh, inode->i_sb, *p_blkno);
 628			clean_bdev_bh_alias(bh);
 629		}
 630
 631		if (folio_test_uptodate(folio)) {
 632			set_buffer_uptodate(bh);
 
 633		} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
 634			   !buffer_new(bh) &&
 635			   ocfs2_should_read_blk(inode, folio, block_start) &&
 636			   (block_start < from || block_end > to)) {
 637			bh_read_nowait(bh, 0);
 638			*wait_bh++=bh;
 639		}
 640
 641		*p_blkno = *p_blkno + 1;
 642	}
 643
 644	/*
 645	 * If we issued read requests - let them complete.
 646	 */
 647	while(wait_bh > wait) {
 648		wait_on_buffer(*--wait_bh);
 649		if (!buffer_uptodate(*wait_bh))
 650			ret = -EIO;
 651	}
 652
 653	if (ret == 0 || !new)
 654		return ret;
 655
 656	/*
 657	 * If we get -EIO above, zero out any newly allocated blocks
 658	 * to avoid exposing stale data.
 659	 */
 660	bh = head;
 661	block_start = 0;
 662	do {
 663		block_end = block_start + bsize;
 664		if (block_end <= from)
 665			goto next_bh;
 666		if (block_start >= to)
 667			break;
 668
 669		folio_zero_range(folio, block_start, bh->b_size);
 670		set_buffer_uptodate(bh);
 671		mark_buffer_dirty(bh);
 672
 673next_bh:
 674		block_start = block_end;
 675		bh = bh->b_this_page;
 676	} while (bh != head);
 677
 678	return ret;
 679}
 680
 681#if (PAGE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
 682#define OCFS2_MAX_CTXT_PAGES	1
 683#else
 684#define OCFS2_MAX_CTXT_PAGES	(OCFS2_MAX_CLUSTERSIZE / PAGE_SIZE)
 685#endif
 686
 687#define OCFS2_MAX_CLUSTERS_PER_PAGE	(PAGE_SIZE / OCFS2_MIN_CLUSTERSIZE)
 688
 689struct ocfs2_unwritten_extent {
 690	struct list_head	ue_node;
 691	struct list_head	ue_ip_node;
 692	u32			ue_cpos;
 693	u32			ue_phys;
 694};
 695
 696/*
 697 * Describe the state of a single cluster to be written to.
 698 */
 699struct ocfs2_write_cluster_desc {
 700	u32		c_cpos;
 701	u32		c_phys;
 702	/*
 703	 * Give this a unique field because c_phys eventually gets
 704	 * filled.
 705	 */
 706	unsigned	c_new;
 707	unsigned	c_clear_unwritten;
 708	unsigned	c_needs_zero;
 709};
 710
 711struct ocfs2_write_ctxt {
 712	/* Logical cluster position / len of write */
 713	u32				w_cpos;
 714	u32				w_clen;
 715
 716	/* First cluster allocated in a nonsparse extend */
 717	u32				w_first_new_cpos;
 718
 719	/* Type of caller. Must be one of buffer, mmap, direct.  */
 720	ocfs2_write_type_t		w_type;
 721
 722	struct ocfs2_write_cluster_desc	w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
 723
 724	/*
 725	 * This is true if page_size > cluster_size.
 726	 *
 727	 * It triggers a set of special cases during write which might
 728	 * have to deal with allocating writes to partial pages.
 729	 */
 730	unsigned int			w_large_pages;
 731
 732	/*
 733	 * Pages involved in this write.
 734	 *
 735	 * w_target_page is the page being written to by the user.
 736	 *
 737	 * w_pages is an array of pages which always contains
 738	 * w_target_page, and in the case of an allocating write with
 739	 * page_size < cluster size, it will contain zero'd and mapped
 740	 * pages adjacent to w_target_page which need to be written
 741	 * out in so that future reads from that region will get
 742	 * zero's.
 743	 */
 744	unsigned int			w_num_pages;
 745	struct page			*w_pages[OCFS2_MAX_CTXT_PAGES];
 746	struct page			*w_target_page;
 747
 748	/*
 749	 * w_target_locked is used for page_mkwrite path indicating no unlocking
 750	 * against w_target_page in ocfs2_write_end_nolock.
 751	 */
 752	unsigned int			w_target_locked:1;
 753
 754	/*
 755	 * ocfs2_write_end() uses this to know what the real range to
 756	 * write in the target should be.
 757	 */
 758	unsigned int			w_target_from;
 759	unsigned int			w_target_to;
 760
 761	/*
 762	 * We could use journal_current_handle() but this is cleaner,
 763	 * IMHO -Mark
 764	 */
 765	handle_t			*w_handle;
 766
 767	struct buffer_head		*w_di_bh;
 768
 769	struct ocfs2_cached_dealloc_ctxt w_dealloc;
 770
 771	struct list_head		w_unwritten_list;
 772	unsigned int			w_unwritten_count;
 773};
 774
 775void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
 776{
 777	int i;
 778
 779	for(i = 0; i < num_pages; i++) {
 780		if (pages[i]) {
 781			unlock_page(pages[i]);
 782			mark_page_accessed(pages[i]);
 783			put_page(pages[i]);
 784		}
 785	}
 786}
 787
 788static void ocfs2_unlock_pages(struct ocfs2_write_ctxt *wc)
 789{
 790	int i;
 791
 792	/*
 793	 * w_target_locked is only set to true in the page_mkwrite() case.
 794	 * The intent is to allow us to lock the target page from write_begin()
 795	 * to write_end(). The caller must hold a ref on w_target_page.
 796	 */
 797	if (wc->w_target_locked) {
 798		BUG_ON(!wc->w_target_page);
 799		for (i = 0; i < wc->w_num_pages; i++) {
 800			if (wc->w_target_page == wc->w_pages[i]) {
 801				wc->w_pages[i] = NULL;
 802				break;
 803			}
 804		}
 805		mark_page_accessed(wc->w_target_page);
 806		put_page(wc->w_target_page);
 807	}
 808	ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
 809}
 810
 811static void ocfs2_free_unwritten_list(struct inode *inode,
 812				 struct list_head *head)
 813{
 814	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 815	struct ocfs2_unwritten_extent *ue = NULL, *tmp = NULL;
 816
 817	list_for_each_entry_safe(ue, tmp, head, ue_node) {
 818		list_del(&ue->ue_node);
 819		spin_lock(&oi->ip_lock);
 820		list_del(&ue->ue_ip_node);
 821		spin_unlock(&oi->ip_lock);
 822		kfree(ue);
 823	}
 824}
 825
 826static void ocfs2_free_write_ctxt(struct inode *inode,
 827				  struct ocfs2_write_ctxt *wc)
 828{
 829	ocfs2_free_unwritten_list(inode, &wc->w_unwritten_list);
 830	ocfs2_unlock_pages(wc);
 831	brelse(wc->w_di_bh);
 832	kfree(wc);
 833}
 834
 835static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
 836				  struct ocfs2_super *osb, loff_t pos,
 837				  unsigned len, ocfs2_write_type_t type,
 838				  struct buffer_head *di_bh)
 839{
 840	u32 cend;
 841	struct ocfs2_write_ctxt *wc;
 842
 843	wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
 844	if (!wc)
 845		return -ENOMEM;
 846
 847	wc->w_cpos = pos >> osb->s_clustersize_bits;
 848	wc->w_first_new_cpos = UINT_MAX;
 849	cend = (pos + len - 1) >> osb->s_clustersize_bits;
 850	wc->w_clen = cend - wc->w_cpos + 1;
 851	get_bh(di_bh);
 852	wc->w_di_bh = di_bh;
 853	wc->w_type = type;
 854
 855	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits))
 856		wc->w_large_pages = 1;
 857	else
 858		wc->w_large_pages = 0;
 859
 860	ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
 861	INIT_LIST_HEAD(&wc->w_unwritten_list);
 862
 863	*wcp = wc;
 864
 865	return 0;
 866}
 867
 868/*
 869 * If a page has any new buffers, zero them out here, and mark them uptodate
 870 * and dirty so they'll be written out (in order to prevent uninitialised
 871 * block data from leaking). And clear the new bit.
 872 */
 873static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
 874{
 875	unsigned int block_start, block_end;
 876	struct buffer_head *head, *bh;
 877
 878	BUG_ON(!PageLocked(page));
 879	if (!page_has_buffers(page))
 880		return;
 881
 882	bh = head = page_buffers(page);
 883	block_start = 0;
 884	do {
 885		block_end = block_start + bh->b_size;
 886
 887		if (buffer_new(bh)) {
 888			if (block_end > from && block_start < to) {
 889				if (!PageUptodate(page)) {
 890					unsigned start, end;
 891
 892					start = max(from, block_start);
 893					end = min(to, block_end);
 894
 895					zero_user_segment(page, start, end);
 896					set_buffer_uptodate(bh);
 897				}
 898
 899				clear_buffer_new(bh);
 900				mark_buffer_dirty(bh);
 901			}
 902		}
 903
 904		block_start = block_end;
 905		bh = bh->b_this_page;
 906	} while (bh != head);
 907}
 908
 909/*
 910 * Only called when we have a failure during allocating write to write
 911 * zero's to the newly allocated region.
 912 */
 913static void ocfs2_write_failure(struct inode *inode,
 914				struct ocfs2_write_ctxt *wc,
 915				loff_t user_pos, unsigned user_len)
 916{
 917	int i;
 918	unsigned from = user_pos & (PAGE_SIZE - 1),
 919		to = user_pos + user_len;
 920	struct page *tmppage;
 921
 922	if (wc->w_target_page)
 923		ocfs2_zero_new_buffers(wc->w_target_page, from, to);
 924
 925	for(i = 0; i < wc->w_num_pages; i++) {
 926		tmppage = wc->w_pages[i];
 927
 928		if (tmppage && page_has_buffers(tmppage)) {
 929			if (ocfs2_should_order_data(inode))
 930				ocfs2_jbd2_inode_add_write(wc->w_handle, inode,
 931							   user_pos, user_len);
 932
 933			block_commit_write(tmppage, from, to);
 934		}
 935	}
 936}
 937
 938static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
 939					struct ocfs2_write_ctxt *wc,
 940					struct page *page, u32 cpos,
 941					loff_t user_pos, unsigned user_len,
 942					int new)
 943{
 944	int ret;
 945	unsigned int map_from = 0, map_to = 0;
 946	unsigned int cluster_start, cluster_end;
 947	unsigned int user_data_from = 0, user_data_to = 0;
 948
 949	ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
 950					&cluster_start, &cluster_end);
 951
 952	/* treat the write as new if the a hole/lseek spanned across
 953	 * the page boundary.
 954	 */
 955	new = new | ((i_size_read(inode) <= page_offset(page)) &&
 956			(page_offset(page) <= user_pos));
 957
 958	if (page == wc->w_target_page) {
 959		map_from = user_pos & (PAGE_SIZE - 1);
 960		map_to = map_from + user_len;
 961
 962		if (new)
 963			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
 964						    cluster_start, cluster_end,
 965						    new);
 966		else
 967			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
 968						    map_from, map_to, new);
 969		if (ret) {
 970			mlog_errno(ret);
 971			goto out;
 972		}
 973
 974		user_data_from = map_from;
 975		user_data_to = map_to;
 976		if (new) {
 977			map_from = cluster_start;
 978			map_to = cluster_end;
 979		}
 980	} else {
 981		/*
 982		 * If we haven't allocated the new page yet, we
 983		 * shouldn't be writing it out without copying user
 984		 * data. This is likely a math error from the caller.
 985		 */
 986		BUG_ON(!new);
 987
 988		map_from = cluster_start;
 989		map_to = cluster_end;
 990
 991		ret = ocfs2_map_page_blocks(page, p_blkno, inode,
 992					    cluster_start, cluster_end, new);
 993		if (ret) {
 994			mlog_errno(ret);
 995			goto out;
 996		}
 997	}
 998
 999	/*
1000	 * Parts of newly allocated pages need to be zero'd.
1001	 *
1002	 * Above, we have also rewritten 'to' and 'from' - as far as
1003	 * the rest of the function is concerned, the entire cluster
1004	 * range inside of a page needs to be written.
1005	 *
1006	 * We can skip this if the page is up to date - it's already
1007	 * been zero'd from being read in as a hole.
1008	 */
1009	if (new && !PageUptodate(page))
1010		ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1011					 cpos, user_data_from, user_data_to);
1012
1013	flush_dcache_page(page);
1014
1015out:
1016	return ret;
1017}
1018
1019/*
1020 * This function will only grab one clusters worth of pages.
1021 */
1022static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1023				      struct ocfs2_write_ctxt *wc,
1024				      u32 cpos, loff_t user_pos,
1025				      unsigned user_len, int new,
1026				      struct page *mmap_page)
1027{
1028	int ret = 0, i;
1029	unsigned long start, target_index, end_index, index;
1030	struct inode *inode = mapping->host;
1031	loff_t last_byte;
1032
1033	target_index = user_pos >> PAGE_SHIFT;
1034
1035	/*
1036	 * Figure out how many pages we'll be manipulating here. For
1037	 * non allocating write, we just change the one
1038	 * page. Otherwise, we'll need a whole clusters worth.  If we're
1039	 * writing past i_size, we only need enough pages to cover the
1040	 * last page of the write.
1041	 */
1042	if (new) {
1043		wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1044		start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1045		/*
1046		 * We need the index *past* the last page we could possibly
1047		 * touch.  This is the page past the end of the write or
1048		 * i_size, whichever is greater.
1049		 */
1050		last_byte = max(user_pos + user_len, i_size_read(inode));
1051		BUG_ON(last_byte < 1);
1052		end_index = ((last_byte - 1) >> PAGE_SHIFT) + 1;
1053		if ((start + wc->w_num_pages) > end_index)
1054			wc->w_num_pages = end_index - start;
1055	} else {
1056		wc->w_num_pages = 1;
1057		start = target_index;
1058	}
1059	end_index = (user_pos + user_len - 1) >> PAGE_SHIFT;
1060
1061	for(i = 0; i < wc->w_num_pages; i++) {
1062		index = start + i;
1063
1064		if (index >= target_index && index <= end_index &&
1065		    wc->w_type == OCFS2_WRITE_MMAP) {
1066			/*
1067			 * ocfs2_pagemkwrite() is a little different
1068			 * and wants us to directly use the page
1069			 * passed in.
1070			 */
1071			lock_page(mmap_page);
1072
1073			/* Exit and let the caller retry */
1074			if (mmap_page->mapping != mapping) {
1075				WARN_ON(mmap_page->mapping);
1076				unlock_page(mmap_page);
1077				ret = -EAGAIN;
1078				goto out;
1079			}
1080
1081			get_page(mmap_page);
1082			wc->w_pages[i] = mmap_page;
1083			wc->w_target_locked = true;
1084		} else if (index >= target_index && index <= end_index &&
1085			   wc->w_type == OCFS2_WRITE_DIRECT) {
1086			/* Direct write has no mapping page. */
1087			wc->w_pages[i] = NULL;
1088			continue;
1089		} else {
1090			wc->w_pages[i] = find_or_create_page(mapping, index,
1091							     GFP_NOFS);
1092			if (!wc->w_pages[i]) {
1093				ret = -ENOMEM;
1094				mlog_errno(ret);
1095				goto out;
1096			}
1097		}
1098		wait_for_stable_page(wc->w_pages[i]);
1099
1100		if (index == target_index)
1101			wc->w_target_page = wc->w_pages[i];
1102	}
1103out:
1104	if (ret)
1105		wc->w_target_locked = false;
1106	return ret;
1107}
1108
1109/*
1110 * Prepare a single cluster for write one cluster into the file.
1111 */
1112static int ocfs2_write_cluster(struct address_space *mapping,
1113			       u32 *phys, unsigned int new,
1114			       unsigned int clear_unwritten,
1115			       unsigned int should_zero,
1116			       struct ocfs2_alloc_context *data_ac,
1117			       struct ocfs2_alloc_context *meta_ac,
1118			       struct ocfs2_write_ctxt *wc, u32 cpos,
1119			       loff_t user_pos, unsigned user_len)
1120{
1121	int ret, i;
1122	u64 p_blkno;
1123	struct inode *inode = mapping->host;
1124	struct ocfs2_extent_tree et;
1125	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
1126
 
1127	if (new) {
1128		u32 tmp_pos;
1129
1130		/*
1131		 * This is safe to call with the page locks - it won't take
1132		 * any additional semaphores or cluster locks.
1133		 */
1134		tmp_pos = cpos;
1135		ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1136					   &tmp_pos, 1, !clear_unwritten,
1137					   wc->w_di_bh, wc->w_handle,
1138					   data_ac, meta_ac, NULL);
1139		/*
1140		 * This shouldn't happen because we must have already
1141		 * calculated the correct meta data allocation required. The
1142		 * internal tree allocation code should know how to increase
1143		 * transaction credits itself.
1144		 *
1145		 * If need be, we could handle -EAGAIN for a
1146		 * RESTART_TRANS here.
1147		 */
1148		mlog_bug_on_msg(ret == -EAGAIN,
1149				"Inode %llu: EAGAIN return during allocation.\n",
1150				(unsigned long long)OCFS2_I(inode)->ip_blkno);
1151		if (ret < 0) {
1152			mlog_errno(ret);
1153			goto out;
1154		}
1155	} else if (clear_unwritten) {
1156		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1157					      wc->w_di_bh);
1158		ret = ocfs2_mark_extent_written(inode, &et,
1159						wc->w_handle, cpos, 1, *phys,
1160						meta_ac, &wc->w_dealloc);
1161		if (ret < 0) {
1162			mlog_errno(ret);
1163			goto out;
1164		}
1165	}
1166
 
 
 
 
 
1167	/*
1168	 * The only reason this should fail is due to an inability to
1169	 * find the extent added.
1170	 */
1171	ret = ocfs2_get_clusters(inode, cpos, phys, NULL, NULL);
 
1172	if (ret < 0) {
1173		mlog(ML_ERROR, "Get physical blkno failed for inode %llu, "
1174			    "at logical cluster %u",
1175			    (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos);
 
1176		goto out;
1177	}
1178
1179	BUG_ON(*phys == 0);
1180
1181	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, *phys);
1182	if (!should_zero)
1183		p_blkno += (user_pos >> inode->i_sb->s_blocksize_bits) & (u64)(bpc - 1);
1184
1185	for(i = 0; i < wc->w_num_pages; i++) {
1186		int tmpret;
1187
1188		/* This is the direct io target page. */
1189		if (wc->w_pages[i] == NULL) {
1190			p_blkno++;
1191			continue;
1192		}
1193
1194		tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1195						      wc->w_pages[i], cpos,
1196						      user_pos, user_len,
1197						      should_zero);
1198		if (tmpret) {
1199			mlog_errno(tmpret);
1200			if (ret == 0)
1201				ret = tmpret;
1202		}
1203	}
1204
1205	/*
1206	 * We only have cleanup to do in case of allocating write.
1207	 */
1208	if (ret && new)
1209		ocfs2_write_failure(inode, wc, user_pos, user_len);
1210
1211out:
1212
1213	return ret;
1214}
1215
1216static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1217				       struct ocfs2_alloc_context *data_ac,
1218				       struct ocfs2_alloc_context *meta_ac,
1219				       struct ocfs2_write_ctxt *wc,
1220				       loff_t pos, unsigned len)
1221{
1222	int ret, i;
1223	loff_t cluster_off;
1224	unsigned int local_len = len;
1225	struct ocfs2_write_cluster_desc *desc;
1226	struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1227
1228	for (i = 0; i < wc->w_clen; i++) {
1229		desc = &wc->w_desc[i];
1230
1231		/*
1232		 * We have to make sure that the total write passed in
1233		 * doesn't extend past a single cluster.
1234		 */
1235		local_len = len;
1236		cluster_off = pos & (osb->s_clustersize - 1);
1237		if ((cluster_off + local_len) > osb->s_clustersize)
1238			local_len = osb->s_clustersize - cluster_off;
1239
1240		ret = ocfs2_write_cluster(mapping, &desc->c_phys,
1241					  desc->c_new,
1242					  desc->c_clear_unwritten,
1243					  desc->c_needs_zero,
1244					  data_ac, meta_ac,
1245					  wc, desc->c_cpos, pos, local_len);
1246		if (ret) {
1247			mlog_errno(ret);
1248			goto out;
1249		}
1250
1251		len -= local_len;
1252		pos += local_len;
1253	}
1254
1255	ret = 0;
1256out:
1257	return ret;
1258}
1259
1260/*
1261 * ocfs2_write_end() wants to know which parts of the target page it
1262 * should complete the write on. It's easiest to compute them ahead of
1263 * time when a more complete view of the write is available.
1264 */
1265static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1266					struct ocfs2_write_ctxt *wc,
1267					loff_t pos, unsigned len, int alloc)
1268{
1269	struct ocfs2_write_cluster_desc *desc;
1270
1271	wc->w_target_from = pos & (PAGE_SIZE - 1);
1272	wc->w_target_to = wc->w_target_from + len;
1273
1274	if (alloc == 0)
1275		return;
1276
1277	/*
1278	 * Allocating write - we may have different boundaries based
1279	 * on page size and cluster size.
1280	 *
1281	 * NOTE: We can no longer compute one value from the other as
1282	 * the actual write length and user provided length may be
1283	 * different.
1284	 */
1285
1286	if (wc->w_large_pages) {
1287		/*
1288		 * We only care about the 1st and last cluster within
1289		 * our range and whether they should be zero'd or not. Either
1290		 * value may be extended out to the start/end of a
1291		 * newly allocated cluster.
1292		 */
1293		desc = &wc->w_desc[0];
1294		if (desc->c_needs_zero)
1295			ocfs2_figure_cluster_boundaries(osb,
1296							desc->c_cpos,
1297							&wc->w_target_from,
1298							NULL);
1299
1300		desc = &wc->w_desc[wc->w_clen - 1];
1301		if (desc->c_needs_zero)
1302			ocfs2_figure_cluster_boundaries(osb,
1303							desc->c_cpos,
1304							NULL,
1305							&wc->w_target_to);
1306	} else {
1307		wc->w_target_from = 0;
1308		wc->w_target_to = PAGE_SIZE;
1309	}
1310}
1311
1312/*
1313 * Check if this extent is marked UNWRITTEN by direct io. If so, we need not to
1314 * do the zero work. And should not to clear UNWRITTEN since it will be cleared
1315 * by the direct io procedure.
1316 * If this is a new extent that allocated by direct io, we should mark it in
1317 * the ip_unwritten_list.
1318 */
1319static int ocfs2_unwritten_check(struct inode *inode,
1320				 struct ocfs2_write_ctxt *wc,
1321				 struct ocfs2_write_cluster_desc *desc)
1322{
1323	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1324	struct ocfs2_unwritten_extent *ue = NULL, *new = NULL;
1325	int ret = 0;
1326
1327	if (!desc->c_needs_zero)
1328		return 0;
1329
1330retry:
1331	spin_lock(&oi->ip_lock);
1332	/* Needs not to zero no metter buffer or direct. The one who is zero
1333	 * the cluster is doing zero. And he will clear unwritten after all
1334	 * cluster io finished. */
1335	list_for_each_entry(ue, &oi->ip_unwritten_list, ue_ip_node) {
1336		if (desc->c_cpos == ue->ue_cpos) {
1337			BUG_ON(desc->c_new);
1338			desc->c_needs_zero = 0;
1339			desc->c_clear_unwritten = 0;
1340			goto unlock;
1341		}
1342	}
1343
1344	if (wc->w_type != OCFS2_WRITE_DIRECT)
1345		goto unlock;
1346
1347	if (new == NULL) {
1348		spin_unlock(&oi->ip_lock);
1349		new = kmalloc(sizeof(struct ocfs2_unwritten_extent),
1350			     GFP_NOFS);
1351		if (new == NULL) {
1352			ret = -ENOMEM;
1353			goto out;
1354		}
1355		goto retry;
1356	}
1357	/* This direct write will doing zero. */
1358	new->ue_cpos = desc->c_cpos;
1359	new->ue_phys = desc->c_phys;
1360	desc->c_clear_unwritten = 0;
1361	list_add_tail(&new->ue_ip_node, &oi->ip_unwritten_list);
1362	list_add_tail(&new->ue_node, &wc->w_unwritten_list);
1363	wc->w_unwritten_count++;
1364	new = NULL;
1365unlock:
1366	spin_unlock(&oi->ip_lock);
1367out:
1368	kfree(new);
1369	return ret;
1370}
1371
1372/*
1373 * Populate each single-cluster write descriptor in the write context
1374 * with information about the i/o to be done.
1375 *
1376 * Returns the number of clusters that will have to be allocated, as
1377 * well as a worst case estimate of the number of extent records that
1378 * would have to be created during a write to an unwritten region.
1379 */
1380static int ocfs2_populate_write_desc(struct inode *inode,
1381				     struct ocfs2_write_ctxt *wc,
1382				     unsigned int *clusters_to_alloc,
1383				     unsigned int *extents_to_split)
1384{
1385	int ret;
1386	struct ocfs2_write_cluster_desc *desc;
1387	unsigned int num_clusters = 0;
1388	unsigned int ext_flags = 0;
1389	u32 phys = 0;
1390	int i;
1391
1392	*clusters_to_alloc = 0;
1393	*extents_to_split = 0;
1394
1395	for (i = 0; i < wc->w_clen; i++) {
1396		desc = &wc->w_desc[i];
1397		desc->c_cpos = wc->w_cpos + i;
1398
1399		if (num_clusters == 0) {
1400			/*
1401			 * Need to look up the next extent record.
1402			 */
1403			ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1404						 &num_clusters, &ext_flags);
1405			if (ret) {
1406				mlog_errno(ret);
1407				goto out;
1408			}
1409
1410			/* We should already CoW the refcountd extent. */
1411			BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1412
1413			/*
1414			 * Assume worst case - that we're writing in
1415			 * the middle of the extent.
1416			 *
1417			 * We can assume that the write proceeds from
1418			 * left to right, in which case the extent
1419			 * insert code is smart enough to coalesce the
1420			 * next splits into the previous records created.
1421			 */
1422			if (ext_flags & OCFS2_EXT_UNWRITTEN)
1423				*extents_to_split = *extents_to_split + 2;
1424		} else if (phys) {
1425			/*
1426			 * Only increment phys if it doesn't describe
1427			 * a hole.
1428			 */
1429			phys++;
1430		}
1431
1432		/*
1433		 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1434		 * file that got extended.  w_first_new_cpos tells us
1435		 * where the newly allocated clusters are so we can
1436		 * zero them.
1437		 */
1438		if (desc->c_cpos >= wc->w_first_new_cpos) {
1439			BUG_ON(phys == 0);
1440			desc->c_needs_zero = 1;
1441		}
1442
1443		desc->c_phys = phys;
1444		if (phys == 0) {
1445			desc->c_new = 1;
1446			desc->c_needs_zero = 1;
1447			desc->c_clear_unwritten = 1;
1448			*clusters_to_alloc = *clusters_to_alloc + 1;
1449		}
1450
1451		if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1452			desc->c_clear_unwritten = 1;
1453			desc->c_needs_zero = 1;
1454		}
1455
1456		ret = ocfs2_unwritten_check(inode, wc, desc);
1457		if (ret) {
1458			mlog_errno(ret);
1459			goto out;
1460		}
1461
1462		num_clusters--;
1463	}
1464
1465	ret = 0;
1466out:
1467	return ret;
1468}
1469
1470static int ocfs2_write_begin_inline(struct address_space *mapping,
1471				    struct inode *inode,
1472				    struct ocfs2_write_ctxt *wc)
1473{
1474	int ret;
1475	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1476	struct page *page;
1477	handle_t *handle;
1478	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1479
1480	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1481	if (IS_ERR(handle)) {
1482		ret = PTR_ERR(handle);
1483		mlog_errno(ret);
1484		goto out;
1485	}
1486
1487	page = find_or_create_page(mapping, 0, GFP_NOFS);
1488	if (!page) {
1489		ocfs2_commit_trans(osb, handle);
1490		ret = -ENOMEM;
1491		mlog_errno(ret);
1492		goto out;
1493	}
1494	/*
1495	 * If we don't set w_num_pages then this page won't get unlocked
1496	 * and freed on cleanup of the write context.
1497	 */
1498	wc->w_pages[0] = wc->w_target_page = page;
1499	wc->w_num_pages = 1;
1500
 
 
 
 
 
 
 
1501	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1502				      OCFS2_JOURNAL_ACCESS_WRITE);
1503	if (ret) {
1504		ocfs2_commit_trans(osb, handle);
1505
1506		mlog_errno(ret);
1507		goto out;
1508	}
1509
1510	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1511		ocfs2_set_inode_data_inline(inode, di);
1512
1513	if (!PageUptodate(page)) {
1514		ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1515		if (ret) {
1516			ocfs2_commit_trans(osb, handle);
1517
1518			goto out;
1519		}
1520	}
1521
1522	wc->w_handle = handle;
1523out:
1524	return ret;
1525}
1526
1527int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1528{
1529	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1530
1531	if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1532		return 1;
1533	return 0;
1534}
1535
1536static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1537					  struct inode *inode, loff_t pos,
1538					  unsigned len, struct page *mmap_page,
1539					  struct ocfs2_write_ctxt *wc)
1540{
1541	int ret, written = 0;
1542	loff_t end = pos + len;
1543	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1544	struct ocfs2_dinode *di = NULL;
1545
1546	trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1547					     len, (unsigned long long)pos,
1548					     oi->ip_dyn_features);
1549
1550	/*
1551	 * Handle inodes which already have inline data 1st.
1552	 */
1553	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1554		if (mmap_page == NULL &&
1555		    ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1556			goto do_inline_write;
1557
1558		/*
1559		 * The write won't fit - we have to give this inode an
1560		 * inline extent list now.
1561		 */
1562		ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1563		if (ret)
1564			mlog_errno(ret);
1565		goto out;
1566	}
1567
1568	/*
1569	 * Check whether the inode can accept inline data.
1570	 */
1571	if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1572		return 0;
1573
1574	/*
1575	 * Check whether the write can fit.
1576	 */
1577	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1578	if (mmap_page ||
1579	    end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1580		return 0;
1581
1582do_inline_write:
1583	ret = ocfs2_write_begin_inline(mapping, inode, wc);
1584	if (ret) {
1585		mlog_errno(ret);
1586		goto out;
1587	}
1588
1589	/*
1590	 * This signals to the caller that the data can be written
1591	 * inline.
1592	 */
1593	written = 1;
1594out:
1595	return written ? written : ret;
1596}
1597
1598/*
1599 * This function only does anything for file systems which can't
1600 * handle sparse files.
1601 *
1602 * What we want to do here is fill in any hole between the current end
1603 * of allocation and the end of our write. That way the rest of the
1604 * write path can treat it as an non-allocating write, which has no
1605 * special case code for sparse/nonsparse files.
1606 */
1607static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1608					struct buffer_head *di_bh,
1609					loff_t pos, unsigned len,
1610					struct ocfs2_write_ctxt *wc)
1611{
1612	int ret;
1613	loff_t newsize = pos + len;
1614
1615	BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1616
1617	if (newsize <= i_size_read(inode))
1618		return 0;
1619
1620	ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1621	if (ret)
1622		mlog_errno(ret);
1623
1624	/* There is no wc if this is call from direct. */
1625	if (wc)
1626		wc->w_first_new_cpos =
1627			ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1628
1629	return ret;
1630}
1631
1632static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1633			   loff_t pos)
1634{
1635	int ret = 0;
1636
1637	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1638	if (pos > i_size_read(inode))
1639		ret = ocfs2_zero_extend(inode, di_bh, pos);
1640
1641	return ret;
1642}
1643
1644int ocfs2_write_begin_nolock(struct address_space *mapping,
1645			     loff_t pos, unsigned len, ocfs2_write_type_t type,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1646			     struct page **pagep, void **fsdata,
1647			     struct buffer_head *di_bh, struct page *mmap_page)
1648{
1649	int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1650	unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1651	struct ocfs2_write_ctxt *wc;
1652	struct inode *inode = mapping->host;
1653	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1654	struct ocfs2_dinode *di;
1655	struct ocfs2_alloc_context *data_ac = NULL;
1656	struct ocfs2_alloc_context *meta_ac = NULL;
1657	handle_t *handle;
1658	struct ocfs2_extent_tree et;
1659	int try_free = 1, ret1;
1660
1661try_again:
1662	ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, type, di_bh);
1663	if (ret) {
1664		mlog_errno(ret);
1665		return ret;
1666	}
1667
1668	if (ocfs2_supports_inline_data(osb)) {
1669		ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1670						     mmap_page, wc);
1671		if (ret == 1) {
1672			ret = 0;
1673			goto success;
1674		}
1675		if (ret < 0) {
1676			mlog_errno(ret);
1677			goto out;
1678		}
1679	}
1680
1681	/* Direct io change i_size late, should not zero tail here. */
1682	if (type != OCFS2_WRITE_DIRECT) {
1683		if (ocfs2_sparse_alloc(osb))
1684			ret = ocfs2_zero_tail(inode, di_bh, pos);
1685		else
1686			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
1687							   len, wc);
1688		if (ret) {
1689			mlog_errno(ret);
1690			goto out;
1691		}
1692	}
1693
1694	ret = ocfs2_check_range_for_refcount(inode, pos, len);
1695	if (ret < 0) {
1696		mlog_errno(ret);
1697		goto out;
1698	} else if (ret == 1) {
1699		clusters_need = wc->w_clen;
1700		ret = ocfs2_refcount_cow(inode, di_bh,
1701					 wc->w_cpos, wc->w_clen, UINT_MAX);
1702		if (ret) {
1703			mlog_errno(ret);
1704			goto out;
1705		}
1706	}
1707
1708	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1709					&extents_to_split);
1710	if (ret) {
1711		mlog_errno(ret);
1712		goto out;
1713	}
1714	clusters_need += clusters_to_alloc;
1715
1716	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1717
1718	trace_ocfs2_write_begin_nolock(
1719			(unsigned long long)OCFS2_I(inode)->ip_blkno,
1720			(long long)i_size_read(inode),
1721			le32_to_cpu(di->i_clusters),
1722			pos, len, type, mmap_page,
1723			clusters_to_alloc, extents_to_split);
1724
1725	/*
1726	 * We set w_target_from, w_target_to here so that
1727	 * ocfs2_write_end() knows which range in the target page to
1728	 * write out. An allocation requires that we write the entire
1729	 * cluster range.
1730	 */
1731	if (clusters_to_alloc || extents_to_split) {
1732		/*
1733		 * XXX: We are stretching the limits of
1734		 * ocfs2_lock_allocators(). It greatly over-estimates
1735		 * the work to be done.
1736		 */
1737		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1738					      wc->w_di_bh);
1739		ret = ocfs2_lock_allocators(inode, &et,
1740					    clusters_to_alloc, extents_to_split,
1741					    &data_ac, &meta_ac);
1742		if (ret) {
1743			mlog_errno(ret);
1744			goto out;
1745		}
1746
1747		if (data_ac)
1748			data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1749
1750		credits = ocfs2_calc_extend_credits(inode->i_sb,
1751						    &di->id2.i_list);
1752	} else if (type == OCFS2_WRITE_DIRECT)
1753		/* direct write needs not to start trans if no extents alloc. */
1754		goto success;
1755
1756	/*
1757	 * We have to zero sparse allocated clusters, unwritten extent clusters,
1758	 * and non-sparse clusters we just extended.  For non-sparse writes,
1759	 * we know zeros will only be needed in the first and/or last cluster.
1760	 */
1761	if (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1762			   wc->w_desc[wc->w_clen - 1].c_needs_zero))
 
1763		cluster_of_pages = 1;
1764	else
1765		cluster_of_pages = 0;
1766
1767	ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1768
1769	handle = ocfs2_start_trans(osb, credits);
1770	if (IS_ERR(handle)) {
1771		ret = PTR_ERR(handle);
1772		mlog_errno(ret);
1773		goto out;
1774	}
1775
1776	wc->w_handle = handle;
1777
1778	if (clusters_to_alloc) {
1779		ret = dquot_alloc_space_nodirty(inode,
1780			ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1781		if (ret)
1782			goto out_commit;
1783	}
1784
 
 
 
1785	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1786				      OCFS2_JOURNAL_ACCESS_WRITE);
1787	if (ret) {
1788		mlog_errno(ret);
1789		goto out_quota;
1790	}
1791
1792	/*
1793	 * Fill our page array first. That way we've grabbed enough so
1794	 * that we can zero and flush if we error after adding the
1795	 * extent.
1796	 */
1797	ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
1798					 cluster_of_pages, mmap_page);
1799	if (ret) {
1800		/*
1801		 * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock
1802		 * the target page. In this case, we exit with no error and no target
1803		 * page. This will trigger the caller, page_mkwrite(), to re-try
1804		 * the operation.
1805		 */
1806		if (type == OCFS2_WRITE_MMAP && ret == -EAGAIN) {
1807			BUG_ON(wc->w_target_page);
1808			ret = 0;
1809			goto out_quota;
1810		}
1811
1812		mlog_errno(ret);
1813		goto out_quota;
1814	}
1815
 
 
 
 
 
 
 
 
 
 
 
 
1816	ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1817					  len);
1818	if (ret) {
1819		mlog_errno(ret);
1820		goto out_quota;
1821	}
1822
1823	if (data_ac)
1824		ocfs2_free_alloc_context(data_ac);
1825	if (meta_ac)
1826		ocfs2_free_alloc_context(meta_ac);
1827
1828success:
1829	if (pagep)
1830		*pagep = wc->w_target_page;
1831	*fsdata = wc;
1832	return 0;
1833out_quota:
1834	if (clusters_to_alloc)
1835		dquot_free_space(inode,
1836			  ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1837out_commit:
1838	ocfs2_commit_trans(osb, handle);
1839
1840out:
1841	/*
1842	 * The mmapped page won't be unlocked in ocfs2_free_write_ctxt(),
1843	 * even in case of error here like ENOSPC and ENOMEM. So, we need
1844	 * to unlock the target page manually to prevent deadlocks when
1845	 * retrying again on ENOSPC, or when returning non-VM_FAULT_LOCKED
1846	 * to VM code.
1847	 */
1848	if (wc->w_target_locked)
1849		unlock_page(mmap_page);
1850
1851	ocfs2_free_write_ctxt(inode, wc);
1852
1853	if (data_ac) {
1854		ocfs2_free_alloc_context(data_ac);
1855		data_ac = NULL;
1856	}
1857	if (meta_ac) {
1858		ocfs2_free_alloc_context(meta_ac);
1859		meta_ac = NULL;
1860	}
1861
1862	if (ret == -ENOSPC && try_free) {
1863		/*
1864		 * Try to free some truncate log so that we can have enough
1865		 * clusters to allocate.
1866		 */
1867		try_free = 0;
1868
1869		ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1870		if (ret1 == 1)
1871			goto try_again;
1872
1873		if (ret1 < 0)
1874			mlog_errno(ret1);
1875	}
1876
1877	return ret;
1878}
1879
1880static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1881			     loff_t pos, unsigned len,
1882			     struct page **pagep, void **fsdata)
1883{
1884	int ret;
1885	struct buffer_head *di_bh = NULL;
1886	struct inode *inode = mapping->host;
1887
1888	ret = ocfs2_inode_lock(inode, &di_bh, 1);
1889	if (ret) {
1890		mlog_errno(ret);
1891		return ret;
1892	}
1893
1894	/*
1895	 * Take alloc sem here to prevent concurrent lookups. That way
1896	 * the mapping, zeroing and tree manipulation within
1897	 * ocfs2_write() will be safe against ->read_folio(). This
1898	 * should also serve to lock out allocation from a shared
1899	 * writeable region.
1900	 */
1901	down_write(&OCFS2_I(inode)->ip_alloc_sem);
1902
1903	ret = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_BUFFER,
1904				       pagep, fsdata, di_bh, NULL);
1905	if (ret) {
1906		mlog_errno(ret);
1907		goto out_fail;
1908	}
1909
1910	brelse(di_bh);
1911
1912	return 0;
1913
1914out_fail:
1915	up_write(&OCFS2_I(inode)->ip_alloc_sem);
1916
1917	brelse(di_bh);
1918	ocfs2_inode_unlock(inode, 1);
1919
1920	return ret;
1921}
1922
1923static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1924				   unsigned len, unsigned *copied,
1925				   struct ocfs2_dinode *di,
1926				   struct ocfs2_write_ctxt *wc)
1927{
1928	void *kaddr;
1929
1930	if (unlikely(*copied < len)) {
1931		if (!PageUptodate(wc->w_target_page)) {
1932			*copied = 0;
1933			return;
1934		}
1935	}
1936
1937	kaddr = kmap_atomic(wc->w_target_page);
1938	memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1939	kunmap_atomic(kaddr);
1940
1941	trace_ocfs2_write_end_inline(
1942	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1943	     (unsigned long long)pos, *copied,
1944	     le16_to_cpu(di->id2.i_data.id_count),
1945	     le16_to_cpu(di->i_dyn_features));
1946}
1947
1948int ocfs2_write_end_nolock(struct address_space *mapping,
1949			   loff_t pos, unsigned len, unsigned copied, void *fsdata)
 
1950{
1951	int i, ret;
1952	unsigned from, to, start = pos & (PAGE_SIZE - 1);
1953	struct inode *inode = mapping->host;
1954	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1955	struct ocfs2_write_ctxt *wc = fsdata;
1956	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1957	handle_t *handle = wc->w_handle;
1958	struct page *tmppage;
1959
1960	BUG_ON(!list_empty(&wc->w_unwritten_list));
1961
1962	if (handle) {
1963		ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode),
1964				wc->w_di_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1965		if (ret) {
1966			copied = ret;
1967			mlog_errno(ret);
1968			goto out;
1969		}
1970	}
1971
1972	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1973		ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1974		goto out_write_size;
1975	}
1976
1977	if (unlikely(copied < len) && wc->w_target_page) {
1978		loff_t new_isize;
1979
1980		if (!PageUptodate(wc->w_target_page))
1981			copied = 0;
1982
1983		new_isize = max_t(loff_t, i_size_read(inode), pos + copied);
1984		if (new_isize > page_offset(wc->w_target_page))
1985			ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1986					       start+len);
1987		else {
1988			/*
1989			 * When page is fully beyond new isize (data copy
1990			 * failed), do not bother zeroing the page. Invalidate
1991			 * it instead so that writeback does not get confused
1992			 * put page & buffer dirty bits into inconsistent
1993			 * state.
1994			 */
1995			block_invalidate_folio(page_folio(wc->w_target_page),
1996						0, PAGE_SIZE);
1997		}
1998	}
1999	if (wc->w_target_page)
2000		flush_dcache_page(wc->w_target_page);
2001
2002	for(i = 0; i < wc->w_num_pages; i++) {
2003		tmppage = wc->w_pages[i];
2004
2005		/* This is the direct io target page. */
2006		if (tmppage == NULL)
2007			continue;
2008
2009		if (tmppage == wc->w_target_page) {
2010			from = wc->w_target_from;
2011			to = wc->w_target_to;
2012
2013			BUG_ON(from > PAGE_SIZE ||
2014			       to > PAGE_SIZE ||
2015			       to < from);
2016		} else {
2017			/*
2018			 * Pages adjacent to the target (if any) imply
2019			 * a hole-filling write in which case we want
2020			 * to flush their entire range.
2021			 */
2022			from = 0;
2023			to = PAGE_SIZE;
2024		}
2025
2026		if (page_has_buffers(tmppage)) {
2027			if (handle && ocfs2_should_order_data(inode)) {
2028				loff_t start_byte =
2029					((loff_t)tmppage->index << PAGE_SHIFT) +
2030					from;
2031				loff_t length = to - from;
2032				ocfs2_jbd2_inode_add_write(handle, inode,
2033							   start_byte, length);
2034			}
2035			block_commit_write(tmppage, from, to);
2036		}
2037	}
2038
2039out_write_size:
2040	/* Direct io do not update i_size here. */
2041	if (wc->w_type != OCFS2_WRITE_DIRECT) {
2042		pos += copied;
2043		if (pos > i_size_read(inode)) {
2044			i_size_write(inode, pos);
2045			mark_inode_dirty(inode);
2046		}
2047		inode->i_blocks = ocfs2_inode_sector_count(inode);
2048		di->i_size = cpu_to_le64((u64)i_size_read(inode));
2049		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
2050		di->i_mtime = di->i_ctime = cpu_to_le64(inode_get_mtime_sec(inode));
2051		di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode_get_mtime_nsec(inode));
2052		if (handle)
2053			ocfs2_update_inode_fsync_trans(handle, inode, 1);
2054	}
2055	if (handle)
2056		ocfs2_journal_dirty(handle, wc->w_di_bh);
2057
2058out:
2059	/* unlock pages before dealloc since it needs acquiring j_trans_barrier
2060	 * lock, or it will cause a deadlock since journal commit threads holds
2061	 * this lock and will ask for the page lock when flushing the data.
2062	 * put it here to preserve the unlock order.
2063	 */
2064	ocfs2_unlock_pages(wc);
2065
2066	if (handle)
2067		ocfs2_commit_trans(osb, handle);
2068
2069	ocfs2_run_deallocs(osb, &wc->w_dealloc);
2070
2071	brelse(wc->w_di_bh);
2072	kfree(wc);
2073
2074	return copied;
2075}
2076
2077static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2078			   loff_t pos, unsigned len, unsigned copied,
2079			   struct page *page, void *fsdata)
2080{
2081	int ret;
2082	struct inode *inode = mapping->host;
2083
2084	ret = ocfs2_write_end_nolock(mapping, pos, len, copied, fsdata);
2085
2086	up_write(&OCFS2_I(inode)->ip_alloc_sem);
2087	ocfs2_inode_unlock(inode, 1);
2088
2089	return ret;
2090}
2091
2092struct ocfs2_dio_write_ctxt {
2093	struct list_head	dw_zero_list;
2094	unsigned		dw_zero_count;
2095	int			dw_orphaned;
2096	pid_t			dw_writer_pid;
2097};
2098
2099static struct ocfs2_dio_write_ctxt *
2100ocfs2_dio_alloc_write_ctx(struct buffer_head *bh, int *alloc)
2101{
2102	struct ocfs2_dio_write_ctxt *dwc = NULL;
2103
2104	if (bh->b_private)
2105		return bh->b_private;
2106
2107	dwc = kmalloc(sizeof(struct ocfs2_dio_write_ctxt), GFP_NOFS);
2108	if (dwc == NULL)
2109		return NULL;
2110	INIT_LIST_HEAD(&dwc->dw_zero_list);
2111	dwc->dw_zero_count = 0;
2112	dwc->dw_orphaned = 0;
2113	dwc->dw_writer_pid = task_pid_nr(current);
2114	bh->b_private = dwc;
2115	*alloc = 1;
2116
2117	return dwc;
2118}
2119
2120static void ocfs2_dio_free_write_ctx(struct inode *inode,
2121				     struct ocfs2_dio_write_ctxt *dwc)
2122{
2123	ocfs2_free_unwritten_list(inode, &dwc->dw_zero_list);
2124	kfree(dwc);
2125}
2126
2127/*
2128 * TODO: Make this into a generic get_blocks function.
2129 *
2130 * From do_direct_io in direct-io.c:
2131 *  "So what we do is to permit the ->get_blocks function to populate
2132 *   bh.b_size with the size of IO which is permitted at this offset and
2133 *   this i_blkbits."
2134 *
2135 * This function is called directly from get_more_blocks in direct-io.c.
2136 *
2137 * called like this: dio->get_blocks(dio->inode, fs_startblk,
2138 * 					fs_count, map_bh, dio->rw == WRITE);
2139 */
2140static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock,
2141			       struct buffer_head *bh_result, int create)
2142{
2143	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2144	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2145	struct ocfs2_write_ctxt *wc;
2146	struct ocfs2_write_cluster_desc *desc = NULL;
2147	struct ocfs2_dio_write_ctxt *dwc = NULL;
2148	struct buffer_head *di_bh = NULL;
2149	u64 p_blkno;
2150	unsigned int i_blkbits = inode->i_sb->s_blocksize_bits;
2151	loff_t pos = iblock << i_blkbits;
2152	sector_t endblk = (i_size_read(inode) - 1) >> i_blkbits;
2153	unsigned len, total_len = bh_result->b_size;
2154	int ret = 0, first_get_block = 0;
2155
2156	len = osb->s_clustersize - (pos & (osb->s_clustersize - 1));
2157	len = min(total_len, len);
2158
2159	/*
2160	 * bh_result->b_size is count in get_more_blocks according to write
2161	 * "pos" and "end", we need map twice to return different buffer state:
2162	 * 1. area in file size, not set NEW;
2163	 * 2. area out file size, set  NEW.
2164	 *
2165	 *		   iblock    endblk
2166	 * |--------|---------|---------|---------
2167	 * |<-------area in file------->|
2168	 */
2169
2170	if ((iblock <= endblk) &&
2171	    ((iblock + ((len - 1) >> i_blkbits)) > endblk))
2172		len = (endblk - iblock + 1) << i_blkbits;
2173
2174	mlog(0, "get block of %lu at %llu:%u req %u\n",
2175			inode->i_ino, pos, len, total_len);
2176
2177	/*
2178	 * Because we need to change file size in ocfs2_dio_end_io_write(), or
2179	 * we may need to add it to orphan dir. So can not fall to fast path
2180	 * while file size will be changed.
2181	 */
2182	if (pos + total_len <= i_size_read(inode)) {
2183
2184		/* This is the fast path for re-write. */
2185		ret = ocfs2_lock_get_block(inode, iblock, bh_result, create);
2186		if (buffer_mapped(bh_result) &&
2187		    !buffer_new(bh_result) &&
2188		    ret == 0)
2189			goto out;
2190
2191		/* Clear state set by ocfs2_get_block. */
2192		bh_result->b_state = 0;
2193	}
2194
2195	dwc = ocfs2_dio_alloc_write_ctx(bh_result, &first_get_block);
2196	if (unlikely(dwc == NULL)) {
2197		ret = -ENOMEM;
2198		mlog_errno(ret);
2199		goto out;
2200	}
2201
2202	if (ocfs2_clusters_for_bytes(inode->i_sb, pos + total_len) >
2203	    ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode)) &&
2204	    !dwc->dw_orphaned) {
2205		/*
2206		 * when we are going to alloc extents beyond file size, add the
2207		 * inode to orphan dir, so we can recall those spaces when
2208		 * system crashed during write.
2209		 */
2210		ret = ocfs2_add_inode_to_orphan(osb, inode);
2211		if (ret < 0) {
2212			mlog_errno(ret);
2213			goto out;
2214		}
2215		dwc->dw_orphaned = 1;
2216	}
2217
2218	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2219	if (ret) {
2220		mlog_errno(ret);
2221		goto out;
2222	}
2223
2224	down_write(&oi->ip_alloc_sem);
2225
2226	if (first_get_block) {
2227		if (ocfs2_sparse_alloc(osb))
2228			ret = ocfs2_zero_tail(inode, di_bh, pos);
2229		else
2230			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
2231							   total_len, NULL);
2232		if (ret < 0) {
2233			mlog_errno(ret);
2234			goto unlock;
2235		}
2236	}
2237
2238	ret = ocfs2_write_begin_nolock(inode->i_mapping, pos, len,
2239				       OCFS2_WRITE_DIRECT, NULL,
2240				       (void **)&wc, di_bh, NULL);
2241	if (ret) {
2242		mlog_errno(ret);
2243		goto unlock;
2244	}
2245
2246	desc = &wc->w_desc[0];
2247
2248	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, desc->c_phys);
2249	BUG_ON(p_blkno == 0);
2250	p_blkno += iblock & (u64)(ocfs2_clusters_to_blocks(inode->i_sb, 1) - 1);
2251
2252	map_bh(bh_result, inode->i_sb, p_blkno);
2253	bh_result->b_size = len;
2254	if (desc->c_needs_zero)
2255		set_buffer_new(bh_result);
2256
2257	if (iblock > endblk)
2258		set_buffer_new(bh_result);
2259
2260	/* May sleep in end_io. It should not happen in a irq context. So defer
2261	 * it to dio work queue. */
2262	set_buffer_defer_completion(bh_result);
2263
2264	if (!list_empty(&wc->w_unwritten_list)) {
2265		struct ocfs2_unwritten_extent *ue = NULL;
2266
2267		ue = list_first_entry(&wc->w_unwritten_list,
2268				      struct ocfs2_unwritten_extent,
2269				      ue_node);
2270		BUG_ON(ue->ue_cpos != desc->c_cpos);
2271		/* The physical address may be 0, fill it. */
2272		ue->ue_phys = desc->c_phys;
2273
2274		list_splice_tail_init(&wc->w_unwritten_list, &dwc->dw_zero_list);
2275		dwc->dw_zero_count += wc->w_unwritten_count;
2276	}
2277
2278	ret = ocfs2_write_end_nolock(inode->i_mapping, pos, len, len, wc);
2279	BUG_ON(ret != len);
2280	ret = 0;
2281unlock:
2282	up_write(&oi->ip_alloc_sem);
2283	ocfs2_inode_unlock(inode, 1);
2284	brelse(di_bh);
2285out:
2286	if (ret < 0)
2287		ret = -EIO;
2288	return ret;
2289}
2290
2291static int ocfs2_dio_end_io_write(struct inode *inode,
2292				  struct ocfs2_dio_write_ctxt *dwc,
2293				  loff_t offset,
2294				  ssize_t bytes)
2295{
2296	struct ocfs2_cached_dealloc_ctxt dealloc;
2297	struct ocfs2_extent_tree et;
2298	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2299	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2300	struct ocfs2_unwritten_extent *ue = NULL;
2301	struct buffer_head *di_bh = NULL;
2302	struct ocfs2_dinode *di;
2303	struct ocfs2_alloc_context *data_ac = NULL;
2304	struct ocfs2_alloc_context *meta_ac = NULL;
2305	handle_t *handle = NULL;
2306	loff_t end = offset + bytes;
2307	int ret = 0, credits = 0;
2308
2309	ocfs2_init_dealloc_ctxt(&dealloc);
2310
2311	/* We do clear unwritten, delete orphan, change i_size here. If neither
2312	 * of these happen, we can skip all this. */
2313	if (list_empty(&dwc->dw_zero_list) &&
2314	    end <= i_size_read(inode) &&
2315	    !dwc->dw_orphaned)
2316		goto out;
2317
2318	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2319	if (ret < 0) {
2320		mlog_errno(ret);
2321		goto out;
2322	}
2323
2324	down_write(&oi->ip_alloc_sem);
2325
2326	/* Delete orphan before acquire i_rwsem. */
2327	if (dwc->dw_orphaned) {
2328		BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
2329
2330		end = end > i_size_read(inode) ? end : 0;
2331
2332		ret = ocfs2_del_inode_from_orphan(osb, inode, di_bh,
2333				!!end, end);
2334		if (ret < 0)
2335			mlog_errno(ret);
2336	}
2337
2338	di = (struct ocfs2_dinode *)di_bh->b_data;
2339
2340	ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
2341
2342	/* Attach dealloc with extent tree in case that we may reuse extents
2343	 * which are already unlinked from current extent tree due to extent
2344	 * rotation and merging.
2345	 */
2346	et.et_dealloc = &dealloc;
2347
2348	ret = ocfs2_lock_allocators(inode, &et, 0, dwc->dw_zero_count*2,
2349				    &data_ac, &meta_ac);
2350	if (ret) {
2351		mlog_errno(ret);
2352		goto unlock;
2353	}
2354
2355	credits = ocfs2_calc_extend_credits(inode->i_sb, &di->id2.i_list);
2356
2357	handle = ocfs2_start_trans(osb, credits);
2358	if (IS_ERR(handle)) {
2359		ret = PTR_ERR(handle);
2360		mlog_errno(ret);
2361		goto unlock;
2362	}
2363	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
2364				      OCFS2_JOURNAL_ACCESS_WRITE);
2365	if (ret) {
2366		mlog_errno(ret);
2367		goto commit;
2368	}
2369
2370	list_for_each_entry(ue, &dwc->dw_zero_list, ue_node) {
2371		ret = ocfs2_mark_extent_written(inode, &et, handle,
2372						ue->ue_cpos, 1,
2373						ue->ue_phys,
2374						meta_ac, &dealloc);
2375		if (ret < 0) {
2376			mlog_errno(ret);
2377			break;
2378		}
2379	}
2380
2381	if (end > i_size_read(inode)) {
2382		ret = ocfs2_set_inode_size(handle, inode, di_bh, end);
2383		if (ret < 0)
2384			mlog_errno(ret);
2385	}
2386commit:
2387	ocfs2_commit_trans(osb, handle);
2388unlock:
2389	up_write(&oi->ip_alloc_sem);
2390	ocfs2_inode_unlock(inode, 1);
2391	brelse(di_bh);
2392out:
2393	if (data_ac)
2394		ocfs2_free_alloc_context(data_ac);
2395	if (meta_ac)
2396		ocfs2_free_alloc_context(meta_ac);
2397	ocfs2_run_deallocs(osb, &dealloc);
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, 0);
2465}
2466
2467const struct address_space_operations ocfs2_aops = {
2468	.dirty_folio		= block_dirty_folio,
2469	.read_folio		= ocfs2_read_folio,
2470	.readahead		= ocfs2_readahead,
2471	.writepages		= ocfs2_writepages,
2472	.write_begin		= ocfs2_write_begin,
2473	.write_end		= ocfs2_write_end,
2474	.bmap			= ocfs2_bmap,
2475	.direct_IO		= ocfs2_direct_IO,
2476	.invalidate_folio	= block_invalidate_folio,
2477	.release_folio		= ocfs2_release_folio,
2478	.migrate_folio		= buffer_migrate_folio,
2479	.is_partially_uptodate	= block_is_partially_uptodate,
2480	.error_remove_folio	= generic_error_remove_folio,
2481};