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, "get_blocks() failed, inode: 0x%p, "
 160		     "block: %llu\n", inode, (unsigned long long)iblock);
 
 161		goto bail;
 162	}
 163
 164	if (max_blocks < count)
 165		count = max_blocks;
 166
 167	/*
 168	 * ocfs2 never allocates in this function - the only time we
 169	 * need to use BH_New is when we're extending i_size on a file
 170	 * system which doesn't support holes, in which case BH_New
 171	 * allows __block_write_begin() to zero.
 172	 *
 173	 * If we see this on a sparse file system, then a truncate has
 174	 * raced us and removed the cluster. In this case, we clear
 175	 * the buffers dirty and uptodate bits and let the buffer code
 176	 * ignore it as a hole.
 177	 */
 178	if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
 179		clear_buffer_dirty(bh_result);
 180		clear_buffer_uptodate(bh_result);
 181		goto bail;
 182	}
 183
 184	/* Treat the unwritten extent as a hole for zeroing purposes. */
 185	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 186		map_bh(bh_result, inode->i_sb, p_blkno);
 187
 188	bh_result->b_size = count << inode->i_blkbits;
 189
 190	if (!ocfs2_sparse_alloc(osb)) {
 191		if (p_blkno == 0) {
 192			err = -EIO;
 193			mlog(ML_ERROR,
 194			     "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
 195			     (unsigned long long)iblock,
 196			     (unsigned long long)p_blkno,
 197			     (unsigned long long)OCFS2_I(inode)->ip_blkno);
 198			mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
 199			dump_stack();
 200			goto bail;
 201		}
 202	}
 203
 204	past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
 205
 206	trace_ocfs2_get_block_end((unsigned long long)OCFS2_I(inode)->ip_blkno,
 207				  (unsigned long long)past_eof);
 208	if (create && (iblock >= past_eof))
 209		set_buffer_new(bh_result);
 210
 211bail:
 212	if (err < 0)
 213		err = -EIO;
 214
 215	return err;
 216}
 217
 218int ocfs2_read_inline_data(struct inode *inode, struct page *page,
 219			   struct buffer_head *di_bh)
 220{
 221	void *kaddr;
 222	loff_t size;
 223	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 224
 225	if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
 226		ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag\n",
 227			    (unsigned long long)OCFS2_I(inode)->ip_blkno);
 228		return -EROFS;
 229	}
 230
 231	size = i_size_read(inode);
 232
 233	if (size > PAGE_SIZE ||
 234	    size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
 235		ocfs2_error(inode->i_sb,
 236			    "Inode %llu has with inline data has bad size: %Lu\n",
 237			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
 238			    (unsigned long long)size);
 239		return -EROFS;
 240	}
 241
 242	kaddr = kmap_atomic(page);
 243	if (size)
 244		memcpy(kaddr, di->id2.i_data.id_data, size);
 245	/* Clear the remaining part of the page */
 246	memset(kaddr + size, 0, PAGE_SIZE - size);
 247	flush_dcache_page(page);
 248	kunmap_atomic(kaddr);
 249
 250	SetPageUptodate(page);
 251
 252	return 0;
 253}
 254
 255static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
 256{
 257	int ret;
 258	struct buffer_head *di_bh = NULL;
 259
 260	BUG_ON(!PageLocked(page));
 261	BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
 262
 263	ret = ocfs2_read_inode_block(inode, &di_bh);
 264	if (ret) {
 265		mlog_errno(ret);
 266		goto out;
 267	}
 268
 269	ret = ocfs2_read_inline_data(inode, page, di_bh);
 270out:
 271	unlock_page(page);
 272
 273	brelse(di_bh);
 274	return ret;
 275}
 276
 277static int ocfs2_read_folio(struct file *file, struct folio *folio)
 278{
 279	struct inode *inode = folio->mapping->host;
 280	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 281	loff_t start = folio_pos(folio);
 282	int ret, unlock = 1;
 283
 284	trace_ocfs2_readpage((unsigned long long)oi->ip_blkno, folio->index);
 
 285
 286	ret = ocfs2_inode_lock_with_page(inode, NULL, 0, &folio->page);
 287	if (ret != 0) {
 288		if (ret == AOP_TRUNCATED_PAGE)
 289			unlock = 0;
 290		mlog_errno(ret);
 291		goto out;
 292	}
 293
 294	if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
 295		/*
 296		 * Unlock the folio and cycle ip_alloc_sem so that we don't
 297		 * busyloop waiting for ip_alloc_sem to unlock
 298		 */
 299		ret = AOP_TRUNCATED_PAGE;
 300		folio_unlock(folio);
 301		unlock = 0;
 302		down_read(&oi->ip_alloc_sem);
 303		up_read(&oi->ip_alloc_sem);
 304		goto out_inode_unlock;
 305	}
 306
 307	/*
 308	 * i_size might have just been updated as we grabed the meta lock.  We
 309	 * might now be discovering a truncate that hit on another node.
 310	 * block_read_full_folio->get_block freaks out if it is asked to read
 311	 * beyond the end of a file, so we check here.  Callers
 312	 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
 313	 * and notice that the folio they just read isn't needed.
 314	 *
 315	 * XXX sys_readahead() seems to get that wrong?
 316	 */
 317	if (start >= i_size_read(inode)) {
 318		folio_zero_segment(folio, 0, folio_size(folio));
 319		folio_mark_uptodate(folio);
 320		ret = 0;
 321		goto out_alloc;
 322	}
 323
 324	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 325		ret = ocfs2_readpage_inline(inode, &folio->page);
 326	else
 327		ret = block_read_full_folio(folio, ocfs2_get_block);
 328	unlock = 0;
 329
 330out_alloc:
 331	up_read(&oi->ip_alloc_sem);
 332out_inode_unlock:
 333	ocfs2_inode_unlock(inode, 0);
 334out:
 335	if (unlock)
 336		folio_unlock(folio);
 337	return ret;
 338}
 339
 340/*
 341 * This is used only for read-ahead. Failures or difficult to handle
 342 * situations are safe to ignore.
 343 *
 344 * Right now, we don't bother with BH_Boundary - in-inode extent lists
 345 * are quite large (243 extents on 4k blocks), so most inodes don't
 346 * grow out to a tree. If need be, detecting boundary extents could
 347 * trivially be added in a future version of ocfs2_get_block().
 348 */
 349static void ocfs2_readahead(struct readahead_control *rac)
 
 350{
 351	int ret;
 352	struct inode *inode = rac->mapping->host;
 353	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 
 
 354
 355	/*
 356	 * Use the nonblocking flag for the dlm code to avoid page
 357	 * lock inversion, but don't bother with retrying.
 358	 */
 359	ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
 360	if (ret)
 361		return;
 362
 363	if (down_read_trylock(&oi->ip_alloc_sem) == 0)
 364		goto out_unlock;
 
 
 365
 366	/*
 367	 * Don't bother with inline-data. There isn't anything
 368	 * to read-ahead in that case anyway...
 369	 */
 370	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 371		goto out_up;
 372
 373	/*
 374	 * Check whether a remote node truncated this file - we just
 375	 * drop out in that case as it's not worth handling here.
 376	 */
 377	if (readahead_pos(rac) >= i_size_read(inode))
 378		goto out_up;
 
 
 379
 380	mpage_readahead(rac, ocfs2_get_block);
 381
 382out_up:
 383	up_read(&oi->ip_alloc_sem);
 384out_unlock:
 
 385	ocfs2_inode_unlock(inode, 0);
 
 
 386}
 387
 388/* Note: Because we don't support holes, our allocation has
 389 * already happened (allocation writes zeros to the file data)
 390 * so we don't have to worry about ordered writes in
 391 * ocfs2_writepages.
 392 *
 393 * ->writepages is called during the process of invalidating the page cache
 394 * during blocked lock processing.  It can't block on any cluster locks
 395 * to during block mapping.  It's relying on the fact that the block
 396 * mapping can't have disappeared under the dirty pages that it is
 397 * being asked to write back.
 398 */
 399static int ocfs2_writepages(struct address_space *mapping,
 400		struct writeback_control *wbc)
 401{
 402	return mpage_writepages(mapping, wbc, ocfs2_get_block);
 
 
 
 
 403}
 404
 405/* Taken from ext3. We don't necessarily need the full blown
 406 * functionality yet, but IMHO it's better to cut and paste the whole
 407 * thing so we can avoid introducing our own bugs (and easily pick up
 408 * their fixes when they happen) --Mark */
 409int walk_page_buffers(	handle_t *handle,
 410			struct buffer_head *head,
 411			unsigned from,
 412			unsigned to,
 413			int *partial,
 414			int (*fn)(	handle_t *handle,
 415					struct buffer_head *bh))
 416{
 417	struct buffer_head *bh;
 418	unsigned block_start, block_end;
 419	unsigned blocksize = head->b_size;
 420	int err, ret = 0;
 421	struct buffer_head *next;
 422
 423	for (	bh = head, block_start = 0;
 424		ret == 0 && (bh != head || !block_start);
 425	    	block_start = block_end, bh = next)
 426	{
 427		next = bh->b_this_page;
 428		block_end = block_start + blocksize;
 429		if (block_end <= from || block_start >= to) {
 430			if (partial && !buffer_uptodate(bh))
 431				*partial = 1;
 432			continue;
 433		}
 434		err = (*fn)(handle, bh);
 435		if (!ret)
 436			ret = err;
 437	}
 438	return ret;
 439}
 440
 441static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
 442{
 443	sector_t status;
 444	u64 p_blkno = 0;
 445	int err = 0;
 446	struct inode *inode = mapping->host;
 447
 448	trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno,
 449			 (unsigned long long)block);
 450
 451	/*
 452	 * The swap code (ab-)uses ->bmap to get a block mapping and then
 453	 * bypasseѕ the file system for actual I/O.  We really can't allow
 454	 * that on refcounted inodes, so we have to skip out here.  And yes,
 455	 * 0 is the magic code for a bmap error..
 456	 */
 457	if (ocfs2_is_refcount_inode(inode))
 458		return 0;
 459
 460	/* We don't need to lock journal system files, since they aren't
 461	 * accessed concurrently from multiple nodes.
 462	 */
 463	if (!INODE_JOURNAL(inode)) {
 464		err = ocfs2_inode_lock(inode, NULL, 0);
 465		if (err) {
 466			if (err != -ENOENT)
 467				mlog_errno(err);
 468			goto bail;
 469		}
 470		down_read(&OCFS2_I(inode)->ip_alloc_sem);
 471	}
 472
 473	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
 474		err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
 475						  NULL);
 476
 477	if (!INODE_JOURNAL(inode)) {
 478		up_read(&OCFS2_I(inode)->ip_alloc_sem);
 479		ocfs2_inode_unlock(inode, 0);
 480	}
 481
 482	if (err) {
 483		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
 484		     (unsigned long long)block);
 485		mlog_errno(err);
 486		goto bail;
 487	}
 488
 489bail:
 490	status = err ? 0 : p_blkno;
 491
 492	return status;
 493}
 494
 495static bool ocfs2_release_folio(struct folio *folio, gfp_t wait)
 496{
 497	if (!folio_buffers(folio))
 498		return false;
 499	return try_to_free_buffers(folio);
 500}
 501
 502static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
 503					    u32 cpos,
 504					    unsigned int *start,
 505					    unsigned int *end)
 506{
 507	unsigned int cluster_start = 0, cluster_end = PAGE_SIZE;
 508
 509	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits)) {
 510		unsigned int cpp;
 511
 512		cpp = 1 << (PAGE_SHIFT - osb->s_clustersize_bits);
 513
 514		cluster_start = cpos % cpp;
 515		cluster_start = cluster_start << osb->s_clustersize_bits;
 516
 517		cluster_end = cluster_start + osb->s_clustersize;
 518	}
 519
 520	BUG_ON(cluster_start > PAGE_SIZE);
 521	BUG_ON(cluster_end > PAGE_SIZE);
 522
 523	if (start)
 524		*start = cluster_start;
 525	if (end)
 526		*end = cluster_end;
 527}
 528
 529/*
 530 * 'from' and 'to' are the region in the page to avoid zeroing.
 531 *
 532 * If pagesize > clustersize, this function will avoid zeroing outside
 533 * of the cluster boundary.
 534 *
 535 * from == to == 0 is code for "zero the entire cluster region"
 536 */
 537static void ocfs2_clear_page_regions(struct page *page,
 538				     struct ocfs2_super *osb, u32 cpos,
 539				     unsigned from, unsigned to)
 540{
 541	void *kaddr;
 542	unsigned int cluster_start, cluster_end;
 543
 544	ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
 545
 546	kaddr = kmap_atomic(page);
 547
 548	if (from || to) {
 549		if (from > cluster_start)
 550			memset(kaddr + cluster_start, 0, from - cluster_start);
 551		if (to < cluster_end)
 552			memset(kaddr + to, 0, cluster_end - to);
 553	} else {
 554		memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
 555	}
 556
 557	kunmap_atomic(kaddr);
 558}
 559
 560/*
 561 * Nonsparse file systems fully allocate before we get to the write
 562 * code. This prevents ocfs2_write() from tagging the write as an
 563 * allocating one, which means ocfs2_map_page_blocks() might try to
 564 * read-in the blocks at the tail of our file. Avoid reading them by
 565 * testing i_size against each block offset.
 566 */
 567static int ocfs2_should_read_blk(struct inode *inode, struct folio *folio,
 568				 unsigned int block_start)
 569{
 570	u64 offset = folio_pos(folio) + block_start;
 571
 572	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
 573		return 1;
 574
 575	if (i_size_read(inode) > offset)
 576		return 1;
 577
 578	return 0;
 579}
 580
 581/*
 582 * Some of this taken from __block_write_begin(). We already have our
 583 * mapping by now though, and the entire write will be allocating or
 584 * it won't, so not much need to use BH_New.
 585 *
 586 * This will also skip zeroing, which is handled externally.
 587 */
 588int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
 589			  struct inode *inode, unsigned int from,
 590			  unsigned int to, int new)
 591{
 592	struct folio *folio = page_folio(page);
 593	int ret = 0;
 594	struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
 595	unsigned int block_end, block_start;
 596	unsigned int bsize = i_blocksize(inode);
 597
 598	head = folio_buffers(folio);
 599	if (!head)
 600		head = create_empty_buffers(folio, bsize, 0);
 601
 
 602	for (bh = head, block_start = 0; bh != head || !block_start;
 603	     bh = bh->b_this_page, block_start += bsize) {
 604		block_end = block_start + bsize;
 605
 606		clear_buffer_new(bh);
 607
 608		/*
 609		 * Ignore blocks outside of our i/o range -
 610		 * they may belong to unallocated clusters.
 611		 */
 612		if (block_start >= to || block_end <= from) {
 613			if (folio_test_uptodate(folio))
 614				set_buffer_uptodate(bh);
 615			continue;
 616		}
 617
 618		/*
 619		 * For an allocating write with cluster size >= page
 620		 * size, we always write the entire page.
 621		 */
 622		if (new)
 623			set_buffer_new(bh);
 624
 625		if (!buffer_mapped(bh)) {
 626			map_bh(bh, inode->i_sb, *p_blkno);
 627			clean_bdev_bh_alias(bh);
 628		}
 629
 630		if (folio_test_uptodate(folio)) {
 631			set_buffer_uptodate(bh);
 
 632		} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
 633			   !buffer_new(bh) &&
 634			   ocfs2_should_read_blk(inode, folio, block_start) &&
 635			   (block_start < from || block_end > to)) {
 636			bh_read_nowait(bh, 0);
 637			*wait_bh++=bh;
 638		}
 639
 640		*p_blkno = *p_blkno + 1;
 641	}
 642
 643	/*
 644	 * If we issued read requests - let them complete.
 645	 */
 646	while(wait_bh > wait) {
 647		wait_on_buffer(*--wait_bh);
 648		if (!buffer_uptodate(*wait_bh))
 649			ret = -EIO;
 650	}
 651
 652	if (ret == 0 || !new)
 653		return ret;
 654
 655	/*
 656	 * If we get -EIO above, zero out any newly allocated blocks
 657	 * to avoid exposing stale data.
 658	 */
 659	bh = head;
 660	block_start = 0;
 661	do {
 662		block_end = block_start + bsize;
 663		if (block_end <= from)
 664			goto next_bh;
 665		if (block_start >= to)
 666			break;
 667
 668		folio_zero_range(folio, block_start, bh->b_size);
 669		set_buffer_uptodate(bh);
 670		mark_buffer_dirty(bh);
 671
 672next_bh:
 673		block_start = block_end;
 674		bh = bh->b_this_page;
 675	} while (bh != head);
 676
 677	return ret;
 678}
 679
 680#if (PAGE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
 681#define OCFS2_MAX_CTXT_PAGES	1
 682#else
 683#define OCFS2_MAX_CTXT_PAGES	(OCFS2_MAX_CLUSTERSIZE / PAGE_SIZE)
 684#endif
 685
 686#define OCFS2_MAX_CLUSTERS_PER_PAGE	(PAGE_SIZE / OCFS2_MIN_CLUSTERSIZE)
 687
 688struct ocfs2_unwritten_extent {
 689	struct list_head	ue_node;
 690	struct list_head	ue_ip_node;
 691	u32			ue_cpos;
 692	u32			ue_phys;
 693};
 694
 695/*
 696 * Describe the state of a single cluster to be written to.
 697 */
 698struct ocfs2_write_cluster_desc {
 699	u32		c_cpos;
 700	u32		c_phys;
 701	/*
 702	 * Give this a unique field because c_phys eventually gets
 703	 * filled.
 704	 */
 705	unsigned	c_new;
 706	unsigned	c_clear_unwritten;
 707	unsigned	c_needs_zero;
 708};
 709
 710struct ocfs2_write_ctxt {
 711	/* Logical cluster position / len of write */
 712	u32				w_cpos;
 713	u32				w_clen;
 714
 715	/* First cluster allocated in a nonsparse extend */
 716	u32				w_first_new_cpos;
 717
 718	/* Type of caller. Must be one of buffer, mmap, direct.  */
 719	ocfs2_write_type_t		w_type;
 720
 721	struct ocfs2_write_cluster_desc	w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
 722
 723	/*
 724	 * This is true if page_size > cluster_size.
 725	 *
 726	 * It triggers a set of special cases during write which might
 727	 * have to deal with allocating writes to partial pages.
 728	 */
 729	unsigned int			w_large_pages;
 730
 731	/*
 732	 * Pages involved in this write.
 733	 *
 734	 * w_target_page is the page being written to by the user.
 735	 *
 736	 * w_pages is an array of pages which always contains
 737	 * w_target_page, and in the case of an allocating write with
 738	 * page_size < cluster size, it will contain zero'd and mapped
 739	 * pages adjacent to w_target_page which need to be written
 740	 * out in so that future reads from that region will get
 741	 * zero's.
 742	 */
 743	unsigned int			w_num_pages;
 744	struct page			*w_pages[OCFS2_MAX_CTXT_PAGES];
 745	struct page			*w_target_page;
 746
 747	/*
 748	 * w_target_locked is used for page_mkwrite path indicating no unlocking
 749	 * against w_target_page in ocfs2_write_end_nolock.
 750	 */
 751	unsigned int			w_target_locked:1;
 752
 753	/*
 754	 * ocfs2_write_end() uses this to know what the real range to
 755	 * write in the target should be.
 756	 */
 757	unsigned int			w_target_from;
 758	unsigned int			w_target_to;
 759
 760	/*
 761	 * We could use journal_current_handle() but this is cleaner,
 762	 * IMHO -Mark
 763	 */
 764	handle_t			*w_handle;
 765
 766	struct buffer_head		*w_di_bh;
 767
 768	struct ocfs2_cached_dealloc_ctxt w_dealloc;
 769
 770	struct list_head		w_unwritten_list;
 771	unsigned int			w_unwritten_count;
 772};
 773
 774void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
 775{
 776	int i;
 777
 778	for(i = 0; i < num_pages; i++) {
 779		if (pages[i]) {
 780			unlock_page(pages[i]);
 781			mark_page_accessed(pages[i]);
 782			put_page(pages[i]);
 783		}
 784	}
 785}
 786
 787static void ocfs2_unlock_pages(struct ocfs2_write_ctxt *wc)
 788{
 789	int i;
 790
 791	/*
 792	 * w_target_locked is only set to true in the page_mkwrite() case.
 793	 * The intent is to allow us to lock the target page from write_begin()
 794	 * to write_end(). The caller must hold a ref on w_target_page.
 795	 */
 796	if (wc->w_target_locked) {
 797		BUG_ON(!wc->w_target_page);
 798		for (i = 0; i < wc->w_num_pages; i++) {
 799			if (wc->w_target_page == wc->w_pages[i]) {
 800				wc->w_pages[i] = NULL;
 801				break;
 802			}
 803		}
 804		mark_page_accessed(wc->w_target_page);
 805		put_page(wc->w_target_page);
 806	}
 807	ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
 808}
 809
 810static void ocfs2_free_unwritten_list(struct inode *inode,
 811				 struct list_head *head)
 812{
 813	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 814	struct ocfs2_unwritten_extent *ue = NULL, *tmp = NULL;
 815
 816	list_for_each_entry_safe(ue, tmp, head, ue_node) {
 817		list_del(&ue->ue_node);
 818		spin_lock(&oi->ip_lock);
 819		list_del(&ue->ue_ip_node);
 820		spin_unlock(&oi->ip_lock);
 821		kfree(ue);
 822	}
 823}
 824
 825static void ocfs2_free_write_ctxt(struct inode *inode,
 826				  struct ocfs2_write_ctxt *wc)
 827{
 828	ocfs2_free_unwritten_list(inode, &wc->w_unwritten_list);
 829	ocfs2_unlock_pages(wc);
 830	brelse(wc->w_di_bh);
 831	kfree(wc);
 832}
 833
 834static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
 835				  struct ocfs2_super *osb, loff_t pos,
 836				  unsigned len, ocfs2_write_type_t type,
 837				  struct buffer_head *di_bh)
 838{
 839	u32 cend;
 840	struct ocfs2_write_ctxt *wc;
 841
 842	wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
 843	if (!wc)
 844		return -ENOMEM;
 845
 846	wc->w_cpos = pos >> osb->s_clustersize_bits;
 847	wc->w_first_new_cpos = UINT_MAX;
 848	cend = (pos + len - 1) >> osb->s_clustersize_bits;
 849	wc->w_clen = cend - wc->w_cpos + 1;
 850	get_bh(di_bh);
 851	wc->w_di_bh = di_bh;
 852	wc->w_type = type;
 853
 854	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits))
 855		wc->w_large_pages = 1;
 856	else
 857		wc->w_large_pages = 0;
 858
 859	ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
 860	INIT_LIST_HEAD(&wc->w_unwritten_list);
 861
 862	*wcp = wc;
 863
 864	return 0;
 865}
 866
 867/*
 868 * If a page has any new buffers, zero them out here, and mark them uptodate
 869 * and dirty so they'll be written out (in order to prevent uninitialised
 870 * block data from leaking). And clear the new bit.
 871 */
 872static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
 873{
 874	unsigned int block_start, block_end;
 875	struct buffer_head *head, *bh;
 876
 877	BUG_ON(!PageLocked(page));
 878	if (!page_has_buffers(page))
 879		return;
 880
 881	bh = head = page_buffers(page);
 882	block_start = 0;
 883	do {
 884		block_end = block_start + bh->b_size;
 885
 886		if (buffer_new(bh)) {
 887			if (block_end > from && block_start < to) {
 888				if (!PageUptodate(page)) {
 889					unsigned start, end;
 890
 891					start = max(from, block_start);
 892					end = min(to, block_end);
 893
 894					zero_user_segment(page, start, end);
 895					set_buffer_uptodate(bh);
 896				}
 897
 898				clear_buffer_new(bh);
 899				mark_buffer_dirty(bh);
 900			}
 901		}
 902
 903		block_start = block_end;
 904		bh = bh->b_this_page;
 905	} while (bh != head);
 906}
 907
 908/*
 909 * Only called when we have a failure during allocating write to write
 910 * zero's to the newly allocated region.
 911 */
 912static void ocfs2_write_failure(struct inode *inode,
 913				struct ocfs2_write_ctxt *wc,
 914				loff_t user_pos, unsigned user_len)
 915{
 916	int i;
 917	unsigned from = user_pos & (PAGE_SIZE - 1),
 918		to = user_pos + user_len;
 919	struct page *tmppage;
 920
 921	if (wc->w_target_page)
 922		ocfs2_zero_new_buffers(wc->w_target_page, from, to);
 923
 924	for(i = 0; i < wc->w_num_pages; i++) {
 925		tmppage = wc->w_pages[i];
 926
 927		if (tmppage && page_has_buffers(tmppage)) {
 928			if (ocfs2_should_order_data(inode))
 929				ocfs2_jbd2_inode_add_write(wc->w_handle, inode,
 930							   user_pos, user_len);
 931
 932			block_commit_write(tmppage, from, to);
 933		}
 934	}
 935}
 936
 937static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
 938					struct ocfs2_write_ctxt *wc,
 939					struct page *page, u32 cpos,
 940					loff_t user_pos, unsigned user_len,
 941					int new)
 942{
 943	int ret;
 944	unsigned int map_from = 0, map_to = 0;
 945	unsigned int cluster_start, cluster_end;
 946	unsigned int user_data_from = 0, user_data_to = 0;
 947
 948	ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
 949					&cluster_start, &cluster_end);
 950
 951	/* treat the write as new if the a hole/lseek spanned across
 952	 * the page boundary.
 953	 */
 954	new = new | ((i_size_read(inode) <= page_offset(page)) &&
 955			(page_offset(page) <= user_pos));
 956
 957	if (page == wc->w_target_page) {
 958		map_from = user_pos & (PAGE_SIZE - 1);
 959		map_to = map_from + user_len;
 960
 961		if (new)
 962			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
 963						    cluster_start, cluster_end,
 964						    new);
 965		else
 966			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
 967						    map_from, map_to, new);
 968		if (ret) {
 969			mlog_errno(ret);
 970			goto out;
 971		}
 972
 973		user_data_from = map_from;
 974		user_data_to = map_to;
 975		if (new) {
 976			map_from = cluster_start;
 977			map_to = cluster_end;
 978		}
 979	} else {
 980		/*
 981		 * If we haven't allocated the new page yet, we
 982		 * shouldn't be writing it out without copying user
 983		 * data. This is likely a math error from the caller.
 984		 */
 985		BUG_ON(!new);
 986
 987		map_from = cluster_start;
 988		map_to = cluster_end;
 989
 990		ret = ocfs2_map_page_blocks(page, p_blkno, inode,
 991					    cluster_start, cluster_end, new);
 992		if (ret) {
 993			mlog_errno(ret);
 994			goto out;
 995		}
 996	}
 997
 998	/*
 999	 * Parts of newly allocated pages need to be zero'd.
1000	 *
1001	 * Above, we have also rewritten 'to' and 'from' - as far as
1002	 * the rest of the function is concerned, the entire cluster
1003	 * range inside of a page needs to be written.
1004	 *
1005	 * We can skip this if the page is up to date - it's already
1006	 * been zero'd from being read in as a hole.
1007	 */
1008	if (new && !PageUptodate(page))
1009		ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1010					 cpos, user_data_from, user_data_to);
1011
1012	flush_dcache_page(page);
1013
1014out:
1015	return ret;
1016}
1017
1018/*
1019 * This function will only grab one clusters worth of pages.
1020 */
1021static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1022				      struct ocfs2_write_ctxt *wc,
1023				      u32 cpos, loff_t user_pos,
1024				      unsigned user_len, int new,
1025				      struct page *mmap_page)
1026{
1027	int ret = 0, i;
1028	unsigned long start, target_index, end_index, index;
1029	struct inode *inode = mapping->host;
1030	loff_t last_byte;
1031
1032	target_index = user_pos >> PAGE_SHIFT;
1033
1034	/*
1035	 * Figure out how many pages we'll be manipulating here. For
1036	 * non allocating write, we just change the one
1037	 * page. Otherwise, we'll need a whole clusters worth.  If we're
1038	 * writing past i_size, we only need enough pages to cover the
1039	 * last page of the write.
1040	 */
1041	if (new) {
1042		wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1043		start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1044		/*
1045		 * We need the index *past* the last page we could possibly
1046		 * touch.  This is the page past the end of the write or
1047		 * i_size, whichever is greater.
1048		 */
1049		last_byte = max(user_pos + user_len, i_size_read(inode));
1050		BUG_ON(last_byte < 1);
1051		end_index = ((last_byte - 1) >> PAGE_SHIFT) + 1;
1052		if ((start + wc->w_num_pages) > end_index)
1053			wc->w_num_pages = end_index - start;
1054	} else {
1055		wc->w_num_pages = 1;
1056		start = target_index;
1057	}
1058	end_index = (user_pos + user_len - 1) >> PAGE_SHIFT;
1059
1060	for(i = 0; i < wc->w_num_pages; i++) {
1061		index = start + i;
1062
1063		if (index >= target_index && index <= end_index &&
1064		    wc->w_type == OCFS2_WRITE_MMAP) {
1065			/*
1066			 * ocfs2_pagemkwrite() is a little different
1067			 * and wants us to directly use the page
1068			 * passed in.
1069			 */
1070			lock_page(mmap_page);
1071
1072			/* Exit and let the caller retry */
1073			if (mmap_page->mapping != mapping) {
1074				WARN_ON(mmap_page->mapping);
1075				unlock_page(mmap_page);
1076				ret = -EAGAIN;
1077				goto out;
1078			}
1079
1080			get_page(mmap_page);
1081			wc->w_pages[i] = mmap_page;
1082			wc->w_target_locked = true;
1083		} else if (index >= target_index && index <= end_index &&
1084			   wc->w_type == OCFS2_WRITE_DIRECT) {
1085			/* Direct write has no mapping page. */
1086			wc->w_pages[i] = NULL;
1087			continue;
1088		} else {
1089			wc->w_pages[i] = find_or_create_page(mapping, index,
1090							     GFP_NOFS);
1091			if (!wc->w_pages[i]) {
1092				ret = -ENOMEM;
1093				mlog_errno(ret);
1094				goto out;
1095			}
1096		}
1097		wait_for_stable_page(wc->w_pages[i]);
1098
1099		if (index == target_index)
1100			wc->w_target_page = wc->w_pages[i];
1101	}
1102out:
1103	if (ret)
1104		wc->w_target_locked = false;
1105	return ret;
1106}
1107
1108/*
1109 * Prepare a single cluster for write one cluster into the file.
1110 */
1111static int ocfs2_write_cluster(struct address_space *mapping,
1112			       u32 *phys, unsigned int new,
1113			       unsigned int clear_unwritten,
1114			       unsigned int should_zero,
1115			       struct ocfs2_alloc_context *data_ac,
1116			       struct ocfs2_alloc_context *meta_ac,
1117			       struct ocfs2_write_ctxt *wc, u32 cpos,
1118			       loff_t user_pos, unsigned user_len)
1119{
1120	int ret, i;
1121	u64 p_blkno;
1122	struct inode *inode = mapping->host;
1123	struct ocfs2_extent_tree et;
1124	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
1125
1126	if (new) {
1127		u32 tmp_pos;
1128
1129		/*
1130		 * This is safe to call with the page locks - it won't take
1131		 * any additional semaphores or cluster locks.
1132		 */
1133		tmp_pos = cpos;
1134		ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1135					   &tmp_pos, 1, !clear_unwritten,
1136					   wc->w_di_bh, wc->w_handle,
1137					   data_ac, meta_ac, NULL);
1138		/*
1139		 * This shouldn't happen because we must have already
1140		 * calculated the correct meta data allocation required. The
1141		 * internal tree allocation code should know how to increase
1142		 * transaction credits itself.
1143		 *
1144		 * If need be, we could handle -EAGAIN for a
1145		 * RESTART_TRANS here.
1146		 */
1147		mlog_bug_on_msg(ret == -EAGAIN,
1148				"Inode %llu: EAGAIN return during allocation.\n",
1149				(unsigned long long)OCFS2_I(inode)->ip_blkno);
1150		if (ret < 0) {
1151			mlog_errno(ret);
1152			goto out;
1153		}
1154	} else if (clear_unwritten) {
1155		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1156					      wc->w_di_bh);
1157		ret = ocfs2_mark_extent_written(inode, &et,
1158						wc->w_handle, cpos, 1, *phys,
1159						meta_ac, &wc->w_dealloc);
1160		if (ret < 0) {
1161			mlog_errno(ret);
1162			goto out;
1163		}
1164	}
1165
1166	/*
1167	 * The only reason this should fail is due to an inability to
1168	 * find the extent added.
1169	 */
1170	ret = ocfs2_get_clusters(inode, cpos, phys, NULL, NULL);
1171	if (ret < 0) {
1172		mlog(ML_ERROR, "Get physical blkno failed for inode %llu, "
1173			    "at logical cluster %u",
1174			    (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos);
1175		goto out;
1176	}
1177
1178	BUG_ON(*phys == 0);
1179
1180	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, *phys);
1181	if (!should_zero)
1182		p_blkno += (user_pos >> inode->i_sb->s_blocksize_bits) & (u64)(bpc - 1);
1183
1184	for(i = 0; i < wc->w_num_pages; i++) {
1185		int tmpret;
1186
1187		/* This is the direct io target page. */
1188		if (wc->w_pages[i] == NULL) {
1189			p_blkno += (1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits));
1190			continue;
1191		}
1192
1193		tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1194						      wc->w_pages[i], cpos,
1195						      user_pos, user_len,
1196						      should_zero);
1197		if (tmpret) {
1198			mlog_errno(tmpret);
1199			if (ret == 0)
1200				ret = tmpret;
1201		}
1202	}
1203
1204	/*
1205	 * We only have cleanup to do in case of allocating write.
1206	 */
1207	if (ret && new)
1208		ocfs2_write_failure(inode, wc, user_pos, user_len);
1209
1210out:
1211
1212	return ret;
1213}
1214
1215static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1216				       struct ocfs2_alloc_context *data_ac,
1217				       struct ocfs2_alloc_context *meta_ac,
1218				       struct ocfs2_write_ctxt *wc,
1219				       loff_t pos, unsigned len)
1220{
1221	int ret, i;
1222	loff_t cluster_off;
1223	unsigned int local_len = len;
1224	struct ocfs2_write_cluster_desc *desc;
1225	struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1226
1227	for (i = 0; i < wc->w_clen; i++) {
1228		desc = &wc->w_desc[i];
1229
1230		/*
1231		 * We have to make sure that the total write passed in
1232		 * doesn't extend past a single cluster.
1233		 */
1234		local_len = len;
1235		cluster_off = pos & (osb->s_clustersize - 1);
1236		if ((cluster_off + local_len) > osb->s_clustersize)
1237			local_len = osb->s_clustersize - cluster_off;
1238
1239		ret = ocfs2_write_cluster(mapping, &desc->c_phys,
1240					  desc->c_new,
1241					  desc->c_clear_unwritten,
1242					  desc->c_needs_zero,
1243					  data_ac, meta_ac,
1244					  wc, desc->c_cpos, pos, local_len);
1245		if (ret) {
1246			mlog_errno(ret);
1247			goto out;
1248		}
1249
1250		len -= local_len;
1251		pos += local_len;
1252	}
1253
1254	ret = 0;
1255out:
1256	return ret;
1257}
1258
1259/*
1260 * ocfs2_write_end() wants to know which parts of the target page it
1261 * should complete the write on. It's easiest to compute them ahead of
1262 * time when a more complete view of the write is available.
1263 */
1264static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1265					struct ocfs2_write_ctxt *wc,
1266					loff_t pos, unsigned len, int alloc)
1267{
1268	struct ocfs2_write_cluster_desc *desc;
1269
1270	wc->w_target_from = pos & (PAGE_SIZE - 1);
1271	wc->w_target_to = wc->w_target_from + len;
1272
1273	if (alloc == 0)
1274		return;
1275
1276	/*
1277	 * Allocating write - we may have different boundaries based
1278	 * on page size and cluster size.
1279	 *
1280	 * NOTE: We can no longer compute one value from the other as
1281	 * the actual write length and user provided length may be
1282	 * different.
1283	 */
1284
1285	if (wc->w_large_pages) {
1286		/*
1287		 * We only care about the 1st and last cluster within
1288		 * our range and whether they should be zero'd or not. Either
1289		 * value may be extended out to the start/end of a
1290		 * newly allocated cluster.
1291		 */
1292		desc = &wc->w_desc[0];
1293		if (desc->c_needs_zero)
1294			ocfs2_figure_cluster_boundaries(osb,
1295							desc->c_cpos,
1296							&wc->w_target_from,
1297							NULL);
1298
1299		desc = &wc->w_desc[wc->w_clen - 1];
1300		if (desc->c_needs_zero)
1301			ocfs2_figure_cluster_boundaries(osb,
1302							desc->c_cpos,
1303							NULL,
1304							&wc->w_target_to);
1305	} else {
1306		wc->w_target_from = 0;
1307		wc->w_target_to = PAGE_SIZE;
1308	}
1309}
1310
1311/*
1312 * Check if this extent is marked UNWRITTEN by direct io. If so, we need not to
1313 * do the zero work. And should not to clear UNWRITTEN since it will be cleared
1314 * by the direct io procedure.
1315 * If this is a new extent that allocated by direct io, we should mark it in
1316 * the ip_unwritten_list.
1317 */
1318static int ocfs2_unwritten_check(struct inode *inode,
1319				 struct ocfs2_write_ctxt *wc,
1320				 struct ocfs2_write_cluster_desc *desc)
1321{
1322	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1323	struct ocfs2_unwritten_extent *ue = NULL, *new = NULL;
1324	int ret = 0;
1325
1326	if (!desc->c_needs_zero)
1327		return 0;
1328
1329retry:
1330	spin_lock(&oi->ip_lock);
1331	/* Needs not to zero no metter buffer or direct. The one who is zero
1332	 * the cluster is doing zero. And he will clear unwritten after all
1333	 * cluster io finished. */
1334	list_for_each_entry(ue, &oi->ip_unwritten_list, ue_ip_node) {
1335		if (desc->c_cpos == ue->ue_cpos) {
1336			BUG_ON(desc->c_new);
1337			desc->c_needs_zero = 0;
1338			desc->c_clear_unwritten = 0;
1339			goto unlock;
1340		}
1341	}
1342
1343	if (wc->w_type != OCFS2_WRITE_DIRECT)
1344		goto unlock;
1345
1346	if (new == NULL) {
1347		spin_unlock(&oi->ip_lock);
1348		new = kmalloc(sizeof(struct ocfs2_unwritten_extent),
1349			     GFP_NOFS);
1350		if (new == NULL) {
1351			ret = -ENOMEM;
1352			goto out;
1353		}
1354		goto retry;
1355	}
1356	/* This direct write will doing zero. */
1357	new->ue_cpos = desc->c_cpos;
1358	new->ue_phys = desc->c_phys;
1359	desc->c_clear_unwritten = 0;
1360	list_add_tail(&new->ue_ip_node, &oi->ip_unwritten_list);
1361	list_add_tail(&new->ue_node, &wc->w_unwritten_list);
1362	wc->w_unwritten_count++;
1363	new = NULL;
1364unlock:
1365	spin_unlock(&oi->ip_lock);
1366out:
1367	kfree(new);
 
1368	return ret;
1369}
1370
1371/*
1372 * Populate each single-cluster write descriptor in the write context
1373 * with information about the i/o to be done.
1374 *
1375 * Returns the number of clusters that will have to be allocated, as
1376 * well as a worst case estimate of the number of extent records that
1377 * would have to be created during a write to an unwritten region.
1378 */
1379static int ocfs2_populate_write_desc(struct inode *inode,
1380				     struct ocfs2_write_ctxt *wc,
1381				     unsigned int *clusters_to_alloc,
1382				     unsigned int *extents_to_split)
1383{
1384	int ret;
1385	struct ocfs2_write_cluster_desc *desc;
1386	unsigned int num_clusters = 0;
1387	unsigned int ext_flags = 0;
1388	u32 phys = 0;
1389	int i;
1390
1391	*clusters_to_alloc = 0;
1392	*extents_to_split = 0;
1393
1394	for (i = 0; i < wc->w_clen; i++) {
1395		desc = &wc->w_desc[i];
1396		desc->c_cpos = wc->w_cpos + i;
1397
1398		if (num_clusters == 0) {
1399			/*
1400			 * Need to look up the next extent record.
1401			 */
1402			ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1403						 &num_clusters, &ext_flags);
1404			if (ret) {
1405				mlog_errno(ret);
1406				goto out;
1407			}
1408
1409			/* We should already CoW the refcountd extent. */
1410			BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1411
1412			/*
1413			 * Assume worst case - that we're writing in
1414			 * the middle of the extent.
1415			 *
1416			 * We can assume that the write proceeds from
1417			 * left to right, in which case the extent
1418			 * insert code is smart enough to coalesce the
1419			 * next splits into the previous records created.
1420			 */
1421			if (ext_flags & OCFS2_EXT_UNWRITTEN)
1422				*extents_to_split = *extents_to_split + 2;
1423		} else if (phys) {
1424			/*
1425			 * Only increment phys if it doesn't describe
1426			 * a hole.
1427			 */
1428			phys++;
1429		}
1430
1431		/*
1432		 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1433		 * file that got extended.  w_first_new_cpos tells us
1434		 * where the newly allocated clusters are so we can
1435		 * zero them.
1436		 */
1437		if (desc->c_cpos >= wc->w_first_new_cpos) {
1438			BUG_ON(phys == 0);
1439			desc->c_needs_zero = 1;
1440		}
1441
1442		desc->c_phys = phys;
1443		if (phys == 0) {
1444			desc->c_new = 1;
1445			desc->c_needs_zero = 1;
1446			desc->c_clear_unwritten = 1;
1447			*clusters_to_alloc = *clusters_to_alloc + 1;
1448		}
1449
1450		if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1451			desc->c_clear_unwritten = 1;
1452			desc->c_needs_zero = 1;
1453		}
1454
1455		ret = ocfs2_unwritten_check(inode, wc, desc);
1456		if (ret) {
1457			mlog_errno(ret);
1458			goto out;
1459		}
1460
1461		num_clusters--;
1462	}
1463
1464	ret = 0;
1465out:
1466	return ret;
1467}
1468
1469static int ocfs2_write_begin_inline(struct address_space *mapping,
1470				    struct inode *inode,
1471				    struct ocfs2_write_ctxt *wc)
1472{
1473	int ret;
1474	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1475	struct page *page;
1476	handle_t *handle;
1477	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1478
1479	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1480	if (IS_ERR(handle)) {
1481		ret = PTR_ERR(handle);
1482		mlog_errno(ret);
1483		goto out;
1484	}
1485
1486	page = find_or_create_page(mapping, 0, GFP_NOFS);
1487	if (!page) {
1488		ocfs2_commit_trans(osb, handle);
1489		ret = -ENOMEM;
1490		mlog_errno(ret);
1491		goto out;
1492	}
1493	/*
1494	 * If we don't set w_num_pages then this page won't get unlocked
1495	 * and freed on cleanup of the write context.
1496	 */
1497	wc->w_pages[0] = wc->w_target_page = page;
1498	wc->w_num_pages = 1;
1499
1500	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1501				      OCFS2_JOURNAL_ACCESS_WRITE);
1502	if (ret) {
1503		ocfs2_commit_trans(osb, handle);
1504
1505		mlog_errno(ret);
1506		goto out;
1507	}
1508
1509	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1510		ocfs2_set_inode_data_inline(inode, di);
1511
1512	if (!PageUptodate(page)) {
1513		ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1514		if (ret) {
1515			ocfs2_commit_trans(osb, handle);
1516
1517			goto out;
1518		}
1519	}
1520
1521	wc->w_handle = handle;
1522out:
1523	return ret;
1524}
1525
1526int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1527{
1528	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1529
1530	if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1531		return 1;
1532	return 0;
1533}
1534
1535static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1536					  struct inode *inode, loff_t pos,
1537					  unsigned len, struct page *mmap_page,
1538					  struct ocfs2_write_ctxt *wc)
1539{
1540	int ret, written = 0;
1541	loff_t end = pos + len;
1542	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1543	struct ocfs2_dinode *di = NULL;
1544
1545	trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1546					     len, (unsigned long long)pos,
1547					     oi->ip_dyn_features);
1548
1549	/*
1550	 * Handle inodes which already have inline data 1st.
1551	 */
1552	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1553		if (mmap_page == NULL &&
1554		    ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1555			goto do_inline_write;
1556
1557		/*
1558		 * The write won't fit - we have to give this inode an
1559		 * inline extent list now.
1560		 */
1561		ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1562		if (ret)
1563			mlog_errno(ret);
1564		goto out;
1565	}
1566
1567	/*
1568	 * Check whether the inode can accept inline data.
1569	 */
1570	if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1571		return 0;
1572
1573	/*
1574	 * Check whether the write can fit.
1575	 */
1576	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1577	if (mmap_page ||
1578	    end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1579		return 0;
1580
1581do_inline_write:
1582	ret = ocfs2_write_begin_inline(mapping, inode, wc);
1583	if (ret) {
1584		mlog_errno(ret);
1585		goto out;
1586	}
1587
1588	/*
1589	 * This signals to the caller that the data can be written
1590	 * inline.
1591	 */
1592	written = 1;
1593out:
1594	return written ? written : ret;
1595}
1596
1597/*
1598 * This function only does anything for file systems which can't
1599 * handle sparse files.
1600 *
1601 * What we want to do here is fill in any hole between the current end
1602 * of allocation and the end of our write. That way the rest of the
1603 * write path can treat it as an non-allocating write, which has no
1604 * special case code for sparse/nonsparse files.
1605 */
1606static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1607					struct buffer_head *di_bh,
1608					loff_t pos, unsigned len,
1609					struct ocfs2_write_ctxt *wc)
1610{
1611	int ret;
1612	loff_t newsize = pos + len;
1613
1614	BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1615
1616	if (newsize <= i_size_read(inode))
1617		return 0;
1618
1619	ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1620	if (ret)
1621		mlog_errno(ret);
1622
1623	/* There is no wc if this is call from direct. */
1624	if (wc)
1625		wc->w_first_new_cpos =
1626			ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1627
1628	return ret;
1629}
1630
1631static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1632			   loff_t pos)
1633{
1634	int ret = 0;
1635
1636	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1637	if (pos > i_size_read(inode))
1638		ret = ocfs2_zero_extend(inode, di_bh, pos);
1639
1640	return ret;
1641}
1642
1643int ocfs2_write_begin_nolock(struct address_space *mapping,
1644			     loff_t pos, unsigned len, ocfs2_write_type_t type,
1645			     struct folio **foliop, void **fsdata,
1646			     struct buffer_head *di_bh, struct page *mmap_page)
1647{
1648	int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1649	unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1650	struct ocfs2_write_ctxt *wc;
1651	struct inode *inode = mapping->host;
1652	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1653	struct ocfs2_dinode *di;
1654	struct ocfs2_alloc_context *data_ac = NULL;
1655	struct ocfs2_alloc_context *meta_ac = NULL;
1656	handle_t *handle;
1657	struct ocfs2_extent_tree et;
1658	int try_free = 1, ret1;
1659
1660try_again:
1661	ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, type, di_bh);
1662	if (ret) {
1663		mlog_errno(ret);
1664		return ret;
1665	}
1666
1667	if (ocfs2_supports_inline_data(osb)) {
1668		ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1669						     mmap_page, wc);
1670		if (ret == 1) {
1671			ret = 0;
1672			goto success;
1673		}
1674		if (ret < 0) {
1675			mlog_errno(ret);
1676			goto out;
1677		}
1678	}
1679
1680	/* Direct io change i_size late, should not zero tail here. */
1681	if (type != OCFS2_WRITE_DIRECT) {
1682		if (ocfs2_sparse_alloc(osb))
1683			ret = ocfs2_zero_tail(inode, di_bh, pos);
1684		else
1685			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
1686							   len, wc);
1687		if (ret) {
1688			mlog_errno(ret);
1689			goto out;
1690		}
1691	}
1692
1693	ret = ocfs2_check_range_for_refcount(inode, pos, len);
1694	if (ret < 0) {
1695		mlog_errno(ret);
1696		goto out;
1697	} else if (ret == 1) {
1698		clusters_need = wc->w_clen;
1699		ret = ocfs2_refcount_cow(inode, di_bh,
1700					 wc->w_cpos, wc->w_clen, UINT_MAX);
1701		if (ret) {
1702			mlog_errno(ret);
1703			goto out;
1704		}
1705	}
1706
1707	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1708					&extents_to_split);
1709	if (ret) {
1710		mlog_errno(ret);
1711		goto out;
1712	}
1713	clusters_need += clusters_to_alloc;
1714
1715	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1716
1717	trace_ocfs2_write_begin_nolock(
1718			(unsigned long long)OCFS2_I(inode)->ip_blkno,
1719			(long long)i_size_read(inode),
1720			le32_to_cpu(di->i_clusters),
1721			pos, len, type, mmap_page,
1722			clusters_to_alloc, extents_to_split);
1723
1724	/*
1725	 * We set w_target_from, w_target_to here so that
1726	 * ocfs2_write_end() knows which range in the target page to
1727	 * write out. An allocation requires that we write the entire
1728	 * cluster range.
1729	 */
1730	if (clusters_to_alloc || extents_to_split) {
1731		/*
1732		 * XXX: We are stretching the limits of
1733		 * ocfs2_lock_allocators(). It greatly over-estimates
1734		 * the work to be done.
1735		 */
1736		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1737					      wc->w_di_bh);
1738		ret = ocfs2_lock_allocators(inode, &et,
1739					    clusters_to_alloc, extents_to_split,
1740					    &data_ac, &meta_ac);
1741		if (ret) {
1742			mlog_errno(ret);
1743			goto out;
1744		}
1745
1746		if (data_ac)
1747			data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1748
1749		credits = ocfs2_calc_extend_credits(inode->i_sb,
1750						    &di->id2.i_list);
1751	} else if (type == OCFS2_WRITE_DIRECT)
1752		/* direct write needs not to start trans if no extents alloc. */
1753		goto success;
1754
1755	/*
1756	 * We have to zero sparse allocated clusters, unwritten extent clusters,
1757	 * and non-sparse clusters we just extended.  For non-sparse writes,
1758	 * we know zeros will only be needed in the first and/or last cluster.
1759	 */
1760	if (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1761			   wc->w_desc[wc->w_clen - 1].c_needs_zero))
1762		cluster_of_pages = 1;
1763	else
1764		cluster_of_pages = 0;
1765
1766	ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1767
1768	handle = ocfs2_start_trans(osb, credits);
1769	if (IS_ERR(handle)) {
1770		ret = PTR_ERR(handle);
1771		mlog_errno(ret);
1772		goto out;
1773	}
1774
1775	wc->w_handle = handle;
1776
1777	if (clusters_to_alloc) {
1778		ret = dquot_alloc_space_nodirty(inode,
1779			ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1780		if (ret)
1781			goto out_commit;
1782	}
1783
1784	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1785				      OCFS2_JOURNAL_ACCESS_WRITE);
1786	if (ret) {
1787		mlog_errno(ret);
1788		goto out_quota;
1789	}
1790
1791	/*
1792	 * Fill our page array first. That way we've grabbed enough so
1793	 * that we can zero and flush if we error after adding the
1794	 * extent.
1795	 */
1796	ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
1797					 cluster_of_pages, mmap_page);
1798	if (ret) {
1799		/*
1800		 * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock
1801		 * the target page. In this case, we exit with no error and no target
1802		 * page. This will trigger the caller, page_mkwrite(), to re-try
1803		 * the operation.
1804		 */
1805		if (type == OCFS2_WRITE_MMAP && ret == -EAGAIN) {
1806			BUG_ON(wc->w_target_page);
1807			ret = 0;
1808			goto out_quota;
1809		}
1810
1811		mlog_errno(ret);
1812		goto out_quota;
1813	}
1814
 
 
 
 
 
 
 
 
 
 
 
 
1815	ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1816					  len);
1817	if (ret) {
1818		mlog_errno(ret);
1819		goto out_quota;
1820	}
1821
1822	if (data_ac)
1823		ocfs2_free_alloc_context(data_ac);
1824	if (meta_ac)
1825		ocfs2_free_alloc_context(meta_ac);
1826
1827success:
1828	if (foliop)
1829		*foliop = page_folio(wc->w_target_page);
1830	*fsdata = wc;
1831	return 0;
1832out_quota:
1833	if (clusters_to_alloc)
1834		dquot_free_space(inode,
1835			  ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1836out_commit:
1837	ocfs2_commit_trans(osb, handle);
1838
1839out:
1840	/*
1841	 * The mmapped page won't be unlocked in ocfs2_free_write_ctxt(),
1842	 * even in case of error here like ENOSPC and ENOMEM. So, we need
1843	 * to unlock the target page manually to prevent deadlocks when
1844	 * retrying again on ENOSPC, or when returning non-VM_FAULT_LOCKED
1845	 * to VM code.
1846	 */
1847	if (wc->w_target_locked)
1848		unlock_page(mmap_page);
1849
1850	ocfs2_free_write_ctxt(inode, wc);
1851
1852	if (data_ac) {
1853		ocfs2_free_alloc_context(data_ac);
1854		data_ac = NULL;
1855	}
1856	if (meta_ac) {
1857		ocfs2_free_alloc_context(meta_ac);
1858		meta_ac = NULL;
1859	}
1860
1861	if (ret == -ENOSPC && try_free) {
1862		/*
1863		 * Try to free some truncate log so that we can have enough
1864		 * clusters to allocate.
1865		 */
1866		try_free = 0;
1867
1868		ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1869		if (ret1 == 1)
1870			goto try_again;
1871
1872		if (ret1 < 0)
1873			mlog_errno(ret1);
1874	}
1875
1876	return ret;
1877}
1878
1879static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1880			     loff_t pos, unsigned len,
1881			     struct folio **foliop, void **fsdata)
1882{
1883	int ret;
1884	struct buffer_head *di_bh = NULL;
1885	struct inode *inode = mapping->host;
1886
1887	ret = ocfs2_inode_lock(inode, &di_bh, 1);
1888	if (ret) {
1889		mlog_errno(ret);
1890		return ret;
1891	}
1892
1893	/*
1894	 * Take alloc sem here to prevent concurrent lookups. That way
1895	 * the mapping, zeroing and tree manipulation within
1896	 * ocfs2_write() will be safe against ->read_folio(). This
1897	 * should also serve to lock out allocation from a shared
1898	 * writeable region.
1899	 */
1900	down_write(&OCFS2_I(inode)->ip_alloc_sem);
1901
1902	ret = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_BUFFER,
1903				       foliop, fsdata, di_bh, NULL);
1904	if (ret) {
1905		mlog_errno(ret);
1906		goto out_fail;
1907	}
1908
1909	brelse(di_bh);
1910
1911	return 0;
1912
1913out_fail:
1914	up_write(&OCFS2_I(inode)->ip_alloc_sem);
1915
1916	brelse(di_bh);
1917	ocfs2_inode_unlock(inode, 1);
1918
1919	return ret;
1920}
1921
1922static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1923				   unsigned len, unsigned *copied,
1924				   struct ocfs2_dinode *di,
1925				   struct ocfs2_write_ctxt *wc)
1926{
1927	void *kaddr;
1928
1929	if (unlikely(*copied < len)) {
1930		if (!PageUptodate(wc->w_target_page)) {
1931			*copied = 0;
1932			return;
1933		}
1934	}
1935
1936	kaddr = kmap_atomic(wc->w_target_page);
1937	memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1938	kunmap_atomic(kaddr);
1939
1940	trace_ocfs2_write_end_inline(
1941	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1942	     (unsigned long long)pos, *copied,
1943	     le16_to_cpu(di->id2.i_data.id_count),
1944	     le16_to_cpu(di->i_dyn_features));
1945}
1946
1947int ocfs2_write_end_nolock(struct address_space *mapping,
1948			   loff_t pos, unsigned len, unsigned copied, void *fsdata)
1949{
1950	int i, ret;
1951	unsigned from, to, start = pos & (PAGE_SIZE - 1);
1952	struct inode *inode = mapping->host;
1953	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1954	struct ocfs2_write_ctxt *wc = fsdata;
1955	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1956	handle_t *handle = wc->w_handle;
1957	struct page *tmppage;
1958
1959	BUG_ON(!list_empty(&wc->w_unwritten_list));
1960
1961	if (handle) {
1962		ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode),
1963				wc->w_di_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1964		if (ret) {
1965			copied = ret;
1966			mlog_errno(ret);
1967			goto out;
1968		}
1969	}
1970
1971	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1972		ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1973		goto out_write_size;
1974	}
1975
1976	if (unlikely(copied < len) && wc->w_target_page) {
1977		loff_t new_isize;
1978
1979		if (!PageUptodate(wc->w_target_page))
1980			copied = 0;
1981
1982		new_isize = max_t(loff_t, i_size_read(inode), pos + copied);
1983		if (new_isize > page_offset(wc->w_target_page))
1984			ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1985					       start+len);
1986		else {
1987			/*
1988			 * When page is fully beyond new isize (data copy
1989			 * failed), do not bother zeroing the page. Invalidate
1990			 * it instead so that writeback does not get confused
1991			 * put page & buffer dirty bits into inconsistent
1992			 * state.
1993			 */
1994			block_invalidate_folio(page_folio(wc->w_target_page),
1995						0, PAGE_SIZE);
1996		}
1997	}
1998	if (wc->w_target_page)
1999		flush_dcache_page(wc->w_target_page);
2000
2001	for(i = 0; i < wc->w_num_pages; i++) {
2002		tmppage = wc->w_pages[i];
2003
2004		/* This is the direct io target page. */
2005		if (tmppage == NULL)
2006			continue;
2007
2008		if (tmppage == wc->w_target_page) {
2009			from = wc->w_target_from;
2010			to = wc->w_target_to;
2011
2012			BUG_ON(from > PAGE_SIZE ||
2013			       to > PAGE_SIZE ||
2014			       to < from);
2015		} else {
2016			/*
2017			 * Pages adjacent to the target (if any) imply
2018			 * a hole-filling write in which case we want
2019			 * to flush their entire range.
2020			 */
2021			from = 0;
2022			to = PAGE_SIZE;
2023		}
2024
2025		if (page_has_buffers(tmppage)) {
2026			if (handle && ocfs2_should_order_data(inode)) {
2027				loff_t start_byte =
2028					((loff_t)tmppage->index << PAGE_SHIFT) +
2029					from;
2030				loff_t length = to - from;
2031				ocfs2_jbd2_inode_add_write(handle, inode,
2032							   start_byte, length);
2033			}
2034			block_commit_write(tmppage, from, to);
2035		}
2036	}
2037
2038out_write_size:
2039	/* Direct io do not update i_size here. */
2040	if (wc->w_type != OCFS2_WRITE_DIRECT) {
2041		pos += copied;
2042		if (pos > i_size_read(inode)) {
2043			i_size_write(inode, pos);
2044			mark_inode_dirty(inode);
2045		}
2046		inode->i_blocks = ocfs2_inode_sector_count(inode);
2047		di->i_size = cpu_to_le64((u64)i_size_read(inode));
2048		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
2049		di->i_mtime = di->i_ctime = cpu_to_le64(inode_get_mtime_sec(inode));
2050		di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode_get_mtime_nsec(inode));
2051		if (handle)
2052			ocfs2_update_inode_fsync_trans(handle, inode, 1);
2053	}
2054	if (handle)
2055		ocfs2_journal_dirty(handle, wc->w_di_bh);
2056
2057out:
2058	/* unlock pages before dealloc since it needs acquiring j_trans_barrier
2059	 * lock, or it will cause a deadlock since journal commit threads holds
2060	 * this lock and will ask for the page lock when flushing the data.
2061	 * put it here to preserve the unlock order.
2062	 */
2063	ocfs2_unlock_pages(wc);
2064
2065	if (handle)
2066		ocfs2_commit_trans(osb, handle);
2067
2068	ocfs2_run_deallocs(osb, &wc->w_dealloc);
2069
2070	brelse(wc->w_di_bh);
2071	kfree(wc);
2072
2073	return copied;
2074}
2075
2076static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2077			   loff_t pos, unsigned len, unsigned copied,
2078			   struct folio *folio, void *fsdata)
2079{
2080	int ret;
2081	struct inode *inode = mapping->host;
2082
2083	ret = ocfs2_write_end_nolock(mapping, pos, len, copied, fsdata);
2084
2085	up_write(&OCFS2_I(inode)->ip_alloc_sem);
2086	ocfs2_inode_unlock(inode, 1);
2087
2088	return ret;
2089}
2090
2091struct ocfs2_dio_write_ctxt {
2092	struct list_head	dw_zero_list;
2093	unsigned		dw_zero_count;
2094	int			dw_orphaned;
2095	pid_t			dw_writer_pid;
2096};
2097
2098static struct ocfs2_dio_write_ctxt *
2099ocfs2_dio_alloc_write_ctx(struct buffer_head *bh, int *alloc)
2100{
2101	struct ocfs2_dio_write_ctxt *dwc = NULL;
2102
2103	if (bh->b_private)
2104		return bh->b_private;
2105
2106	dwc = kmalloc(sizeof(struct ocfs2_dio_write_ctxt), GFP_NOFS);
2107	if (dwc == NULL)
2108		return NULL;
2109	INIT_LIST_HEAD(&dwc->dw_zero_list);
2110	dwc->dw_zero_count = 0;
2111	dwc->dw_orphaned = 0;
2112	dwc->dw_writer_pid = task_pid_nr(current);
2113	bh->b_private = dwc;
2114	*alloc = 1;
2115
2116	return dwc;
2117}
2118
2119static void ocfs2_dio_free_write_ctx(struct inode *inode,
2120				     struct ocfs2_dio_write_ctxt *dwc)
2121{
2122	ocfs2_free_unwritten_list(inode, &dwc->dw_zero_list);
2123	kfree(dwc);
2124}
2125
2126/*
2127 * TODO: Make this into a generic get_blocks function.
2128 *
2129 * From do_direct_io in direct-io.c:
2130 *  "So what we do is to permit the ->get_blocks function to populate
2131 *   bh.b_size with the size of IO which is permitted at this offset and
2132 *   this i_blkbits."
2133 *
2134 * This function is called directly from get_more_blocks in direct-io.c.
2135 *
2136 * called like this: dio->get_blocks(dio->inode, fs_startblk,
2137 * 					fs_count, map_bh, dio->rw == WRITE);
2138 */
2139static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock,
2140			       struct buffer_head *bh_result, int create)
2141{
2142	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2143	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2144	struct ocfs2_write_ctxt *wc;
2145	struct ocfs2_write_cluster_desc *desc = NULL;
2146	struct ocfs2_dio_write_ctxt *dwc = NULL;
2147	struct buffer_head *di_bh = NULL;
2148	u64 p_blkno;
2149	unsigned int i_blkbits = inode->i_sb->s_blocksize_bits;
2150	loff_t pos = iblock << i_blkbits;
2151	sector_t endblk = (i_size_read(inode) - 1) >> i_blkbits;
2152	unsigned len, total_len = bh_result->b_size;
2153	int ret = 0, first_get_block = 0;
2154
2155	len = osb->s_clustersize - (pos & (osb->s_clustersize - 1));
2156	len = min(total_len, len);
2157
2158	/*
2159	 * bh_result->b_size is count in get_more_blocks according to write
2160	 * "pos" and "end", we need map twice to return different buffer state:
2161	 * 1. area in file size, not set NEW;
2162	 * 2. area out file size, set  NEW.
2163	 *
2164	 *		   iblock    endblk
2165	 * |--------|---------|---------|---------
2166	 * |<-------area in file------->|
2167	 */
2168
2169	if ((iblock <= endblk) &&
2170	    ((iblock + ((len - 1) >> i_blkbits)) > endblk))
2171		len = (endblk - iblock + 1) << i_blkbits;
2172
2173	mlog(0, "get block of %lu at %llu:%u req %u\n",
2174			inode->i_ino, pos, len, total_len);
2175
2176	/*
2177	 * Because we need to change file size in ocfs2_dio_end_io_write(), or
2178	 * we may need to add it to orphan dir. So can not fall to fast path
2179	 * while file size will be changed.
2180	 */
2181	if (pos + total_len <= i_size_read(inode)) {
2182
2183		/* This is the fast path for re-write. */
2184		ret = ocfs2_lock_get_block(inode, iblock, bh_result, create);
2185		if (buffer_mapped(bh_result) &&
2186		    !buffer_new(bh_result) &&
2187		    ret == 0)
2188			goto out;
2189
2190		/* Clear state set by ocfs2_get_block. */
2191		bh_result->b_state = 0;
2192	}
2193
2194	dwc = ocfs2_dio_alloc_write_ctx(bh_result, &first_get_block);
2195	if (unlikely(dwc == NULL)) {
2196		ret = -ENOMEM;
2197		mlog_errno(ret);
2198		goto out;
2199	}
2200
2201	if (ocfs2_clusters_for_bytes(inode->i_sb, pos + total_len) >
2202	    ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode)) &&
2203	    !dwc->dw_orphaned) {
2204		/*
2205		 * when we are going to alloc extents beyond file size, add the
2206		 * inode to orphan dir, so we can recall those spaces when
2207		 * system crashed during write.
2208		 */
2209		ret = ocfs2_add_inode_to_orphan(osb, inode);
2210		if (ret < 0) {
2211			mlog_errno(ret);
2212			goto out;
2213		}
2214		dwc->dw_orphaned = 1;
2215	}
2216
2217	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2218	if (ret) {
2219		mlog_errno(ret);
2220		goto out;
2221	}
2222
2223	down_write(&oi->ip_alloc_sem);
2224
2225	if (first_get_block) {
2226		if (ocfs2_sparse_alloc(osb))
2227			ret = ocfs2_zero_tail(inode, di_bh, pos);
2228		else
2229			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
2230							   total_len, NULL);
2231		if (ret < 0) {
2232			mlog_errno(ret);
2233			goto unlock;
2234		}
2235	}
2236
2237	ret = ocfs2_write_begin_nolock(inode->i_mapping, pos, len,
2238				       OCFS2_WRITE_DIRECT, NULL,
2239				       (void **)&wc, di_bh, NULL);
2240	if (ret) {
2241		mlog_errno(ret);
2242		goto unlock;
2243	}
2244
2245	desc = &wc->w_desc[0];
2246
2247	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, desc->c_phys);
2248	BUG_ON(p_blkno == 0);
2249	p_blkno += iblock & (u64)(ocfs2_clusters_to_blocks(inode->i_sb, 1) - 1);
2250
2251	map_bh(bh_result, inode->i_sb, p_blkno);
2252	bh_result->b_size = len;
2253	if (desc->c_needs_zero)
2254		set_buffer_new(bh_result);
2255
2256	if (iblock > endblk)
2257		set_buffer_new(bh_result);
2258
2259	/* May sleep in end_io. It should not happen in a irq context. So defer
2260	 * it to dio work queue. */
2261	set_buffer_defer_completion(bh_result);
2262
2263	if (!list_empty(&wc->w_unwritten_list)) {
2264		struct ocfs2_unwritten_extent *ue = NULL;
2265
2266		ue = list_first_entry(&wc->w_unwritten_list,
2267				      struct ocfs2_unwritten_extent,
2268				      ue_node);
2269		BUG_ON(ue->ue_cpos != desc->c_cpos);
2270		/* The physical address may be 0, fill it. */
2271		ue->ue_phys = desc->c_phys;
2272
2273		list_splice_tail_init(&wc->w_unwritten_list, &dwc->dw_zero_list);
2274		dwc->dw_zero_count += wc->w_unwritten_count;
2275	}
2276
2277	ret = ocfs2_write_end_nolock(inode->i_mapping, pos, len, len, wc);
2278	BUG_ON(ret != len);
2279	ret = 0;
2280unlock:
2281	up_write(&oi->ip_alloc_sem);
2282	ocfs2_inode_unlock(inode, 1);
2283	brelse(di_bh);
2284out:
 
 
2285	return ret;
2286}
2287
2288static int ocfs2_dio_end_io_write(struct inode *inode,
2289				  struct ocfs2_dio_write_ctxt *dwc,
2290				  loff_t offset,
2291				  ssize_t bytes)
2292{
2293	struct ocfs2_cached_dealloc_ctxt dealloc;
2294	struct ocfs2_extent_tree et;
2295	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2296	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2297	struct ocfs2_unwritten_extent *ue = NULL;
2298	struct buffer_head *di_bh = NULL;
2299	struct ocfs2_dinode *di;
2300	struct ocfs2_alloc_context *data_ac = NULL;
2301	struct ocfs2_alloc_context *meta_ac = NULL;
2302	handle_t *handle = NULL;
2303	loff_t end = offset + bytes;
2304	int ret = 0, credits = 0;
2305
2306	ocfs2_init_dealloc_ctxt(&dealloc);
2307
2308	/* We do clear unwritten, delete orphan, change i_size here. If neither
2309	 * of these happen, we can skip all this. */
2310	if (list_empty(&dwc->dw_zero_list) &&
2311	    end <= i_size_read(inode) &&
2312	    !dwc->dw_orphaned)
2313		goto out;
2314
 
 
 
 
 
 
 
2315	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2316	if (ret < 0) {
2317		mlog_errno(ret);
2318		goto out;
2319	}
2320
2321	down_write(&oi->ip_alloc_sem);
2322
2323	/* Delete orphan before acquire i_rwsem. */
2324	if (dwc->dw_orphaned) {
2325		BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
2326
2327		end = end > i_size_read(inode) ? end : 0;
2328
2329		ret = ocfs2_del_inode_from_orphan(osb, inode, di_bh,
2330				!!end, end);
2331		if (ret < 0)
2332			mlog_errno(ret);
2333	}
2334
2335	di = (struct ocfs2_dinode *)di_bh->b_data;
2336
2337	ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
2338
2339	/* Attach dealloc with extent tree in case that we may reuse extents
2340	 * which are already unlinked from current extent tree due to extent
2341	 * rotation and merging.
2342	 */
2343	et.et_dealloc = &dealloc;
2344
2345	ret = ocfs2_lock_allocators(inode, &et, 0, dwc->dw_zero_count*2,
2346				    &data_ac, &meta_ac);
2347	if (ret) {
2348		mlog_errno(ret);
2349		goto unlock;
2350	}
2351
2352	credits = ocfs2_calc_extend_credits(inode->i_sb, &di->id2.i_list);
2353
2354	handle = ocfs2_start_trans(osb, credits);
2355	if (IS_ERR(handle)) {
2356		ret = PTR_ERR(handle);
2357		mlog_errno(ret);
2358		goto unlock;
2359	}
2360	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
2361				      OCFS2_JOURNAL_ACCESS_WRITE);
2362	if (ret) {
2363		mlog_errno(ret);
2364		goto commit;
2365	}
2366
2367	list_for_each_entry(ue, &dwc->dw_zero_list, ue_node) {
2368		ret = ocfs2_assure_trans_credits(handle, credits);
2369		if (ret < 0) {
2370			mlog_errno(ret);
2371			break;
2372		}
2373		ret = ocfs2_mark_extent_written(inode, &et, handle,
2374						ue->ue_cpos, 1,
2375						ue->ue_phys,
2376						meta_ac, &dealloc);
2377		if (ret < 0) {
2378			mlog_errno(ret);
2379			break;
2380		}
2381	}
2382
2383	if (end > i_size_read(inode)) {
2384		ret = ocfs2_set_inode_size(handle, inode, di_bh, end);
2385		if (ret < 0)
2386			mlog_errno(ret);
2387	}
2388commit:
2389	ocfs2_commit_trans(osb, handle);
2390unlock:
2391	up_write(&oi->ip_alloc_sem);
2392	ocfs2_inode_unlock(inode, 1);
2393	brelse(di_bh);
2394out:
2395	if (data_ac)
2396		ocfs2_free_alloc_context(data_ac);
2397	if (meta_ac)
2398		ocfs2_free_alloc_context(meta_ac);
2399	ocfs2_run_deallocs(osb, &dealloc);
 
 
2400	ocfs2_dio_free_write_ctx(inode, dwc);
2401
2402	return ret;
2403}
2404
2405/*
2406 * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
2407 * particularly interested in the aio/dio case.  We use the rw_lock DLM lock
2408 * to protect io on one node from truncation on another.
2409 */
2410static int ocfs2_dio_end_io(struct kiocb *iocb,
2411			    loff_t offset,
2412			    ssize_t bytes,
2413			    void *private)
2414{
2415	struct inode *inode = file_inode(iocb->ki_filp);
2416	int level;
2417	int ret = 0;
2418
2419	/* this io's submitter should not have unlocked this before we could */
2420	BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
2421
2422	if (bytes <= 0)
2423		mlog_ratelimited(ML_ERROR, "Direct IO failed, bytes = %lld",
2424				 (long long)bytes);
2425	if (private) {
2426		if (bytes > 0)
2427			ret = ocfs2_dio_end_io_write(inode, private, offset,
2428						     bytes);
2429		else
2430			ocfs2_dio_free_write_ctx(inode, private);
2431	}
2432
2433	ocfs2_iocb_clear_rw_locked(iocb);
2434
2435	level = ocfs2_iocb_rw_locked_level(iocb);
2436	ocfs2_rw_unlock(inode, level);
2437	return ret;
2438}
2439
2440static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
2441{
2442	struct file *file = iocb->ki_filp;
2443	struct inode *inode = file->f_mapping->host;
2444	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2445	get_block_t *get_block;
2446
2447	/*
2448	 * Fallback to buffered I/O if we see an inode without
2449	 * extents.
2450	 */
2451	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
2452		return 0;
2453
2454	/* Fallback to buffered I/O if we do not support append dio. */
2455	if (iocb->ki_pos + iter->count > i_size_read(inode) &&
2456	    !ocfs2_supports_append_dio(osb))
2457		return 0;
2458
2459	if (iov_iter_rw(iter) == READ)
2460		get_block = ocfs2_lock_get_block;
2461	else
2462		get_block = ocfs2_dio_wr_get_block;
2463
2464	return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
2465				    iter, get_block,
2466				    ocfs2_dio_end_io, 0);
2467}
2468
2469const struct address_space_operations ocfs2_aops = {
2470	.dirty_folio		= block_dirty_folio,
2471	.read_folio		= ocfs2_read_folio,
2472	.readahead		= ocfs2_readahead,
2473	.writepages		= ocfs2_writepages,
2474	.write_begin		= ocfs2_write_begin,
2475	.write_end		= ocfs2_write_end,
2476	.bmap			= ocfs2_bmap,
2477	.direct_IO		= ocfs2_direct_IO,
2478	.invalidate_folio	= block_invalidate_folio,
2479	.release_folio		= ocfs2_release_folio,
2480	.migrate_folio		= buffer_migrate_folio,
2481	.is_partially_uptodate	= block_is_partially_uptodate,
2482	.error_remove_folio	= generic_error_remove_folio,
2483};