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 
ocfs2_symlink_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)40 static 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 
50 	trace_ocfs2_symlink_get_block(
51 			(unsigned long long)OCFS2_I(inode)->ip_blkno,
52 			(unsigned long long)iblock, bh_result, create);
53 
54 	BUG_ON(ocfs2_inode_is_fast_symlink(inode));
55 
56 	if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
57 		mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
58 		     (unsigned long long)iblock);
59 		goto bail;
60 	}
61 
62 	status = ocfs2_read_inode_block(inode, &bh);
63 	if (status < 0) {
64 		mlog_errno(status);
65 		goto bail;
66 	}
67 	fe = (struct ocfs2_dinode *) bh->b_data;
68 
69 	if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
70 						    le32_to_cpu(fe->i_clusters))) {
71 		err = -ENOMEM;
72 		mlog(ML_ERROR, "block offset is outside the allocated size: "
73 		     "%llu\n", (unsigned long long)iblock);
74 		goto bail;
75 	}
76 
77 	/* We don't use the page cache to create symlink data, so if
78 	 * need be, copy it over from the buffer cache. */
79 	if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
80 		u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
81 			    iblock;
82 		buffer_cache_bh = sb_getblk(osb->sb, blkno);
83 		if (!buffer_cache_bh) {
84 			err = -ENOMEM;
85 			mlog(ML_ERROR, "couldn't getblock for symlink!\n");
86 			goto bail;
87 		}
88 
89 		/* we haven't locked out transactions, so a commit
90 		 * could've happened. Since we've got a reference on
91 		 * the bh, even if it commits while we're doing the
92 		 * copy, the data is still good. */
93 		if (buffer_jbd(buffer_cache_bh) && ocfs2_inode_is_new(inode)) {
94 			memcpy_to_folio(bh_result->b_folio,
95 					bh_result->b_size * iblock,
96 					buffer_cache_bh->b_data,
97 					bh_result->b_size);
98 			set_buffer_uptodate(bh_result);
99 		}
100 		brelse(buffer_cache_bh);
101 	}
102 
103 	map_bh(bh_result, inode->i_sb,
104 	       le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
105 
106 	err = 0;
107 
108 bail:
109 	brelse(bh);
110 
111 	return err;
112 }
113 
ocfs2_lock_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)114 static int ocfs2_lock_get_block(struct inode *inode, sector_t iblock,
115 		    struct buffer_head *bh_result, int create)
116 {
117 	int ret = 0;
118 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
119 
120 	down_read(&oi->ip_alloc_sem);
121 	ret = ocfs2_get_block(inode, iblock, bh_result, create);
122 	up_read(&oi->ip_alloc_sem);
123 
124 	return ret;
125 }
126 
ocfs2_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)127 int ocfs2_get_block(struct inode *inode, sector_t iblock,
128 		    struct buffer_head *bh_result, int create)
129 {
130 	int err = 0;
131 	unsigned int ext_flags;
132 	u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
133 	u64 p_blkno, count, past_eof;
134 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
135 
136 	trace_ocfs2_get_block((unsigned long long)OCFS2_I(inode)->ip_blkno,
137 			      (unsigned long long)iblock, bh_result, create);
138 
139 	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
140 		mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
141 		     inode, inode->i_ino);
142 
143 	if (S_ISLNK(inode->i_mode)) {
144 		/* this always does I/O for some reason. */
145 		err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
146 		goto bail;
147 	}
148 
149 	err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
150 					  &ext_flags);
151 	if (err) {
152 		mlog(ML_ERROR, "get_blocks() failed, inode: 0x%p, "
153 		     "block: %llu\n", inode, (unsigned long long)iblock);
154 		goto bail;
155 	}
156 
157 	if (max_blocks < count)
158 		count = max_blocks;
159 
160 	/*
161 	 * ocfs2 never allocates in this function - the only time we
162 	 * need to use BH_New is when we're extending i_size on a file
163 	 * system which doesn't support holes, in which case BH_New
164 	 * allows __block_write_begin() to zero.
165 	 *
166 	 * If we see this on a sparse file system, then a truncate has
167 	 * raced us and removed the cluster. In this case, we clear
168 	 * the buffers dirty and uptodate bits and let the buffer code
169 	 * ignore it as a hole.
170 	 */
171 	if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
172 		clear_buffer_dirty(bh_result);
173 		clear_buffer_uptodate(bh_result);
174 		goto bail;
175 	}
176 
177 	/* Treat the unwritten extent as a hole for zeroing purposes. */
178 	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
179 		map_bh(bh_result, inode->i_sb, p_blkno);
180 
181 	bh_result->b_size = count << inode->i_blkbits;
182 
183 	if (!ocfs2_sparse_alloc(osb)) {
184 		if (p_blkno == 0) {
185 			err = -EIO;
186 			mlog(ML_ERROR,
187 			     "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
188 			     (unsigned long long)iblock,
189 			     (unsigned long long)p_blkno,
190 			     (unsigned long long)OCFS2_I(inode)->ip_blkno);
191 			mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
192 			dump_stack();
193 			goto bail;
194 		}
195 	}
196 
197 	past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
198 
199 	trace_ocfs2_get_block_end((unsigned long long)OCFS2_I(inode)->ip_blkno,
200 				  (unsigned long long)past_eof);
201 	if (create && (iblock >= past_eof))
202 		set_buffer_new(bh_result);
203 
204 bail:
205 	if (err < 0)
206 		err = -EIO;
207 
208 	return err;
209 }
210 
ocfs2_read_inline_data(struct inode * inode,struct folio * folio,struct buffer_head * di_bh)211 int ocfs2_read_inline_data(struct inode *inode, struct folio *folio,
212 			   struct buffer_head *di_bh)
213 {
214 	loff_t size;
215 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
216 
217 	if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
218 		ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag\n",
219 			    (unsigned long long)OCFS2_I(inode)->ip_blkno);
220 		return -EROFS;
221 	}
222 
223 	size = i_size_read(inode);
224 
225 	if (size > folio_size(folio) ||
226 	    size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
227 		ocfs2_error(inode->i_sb,
228 			    "Inode %llu has with inline data has bad size: %Lu\n",
229 			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
230 			    (unsigned long long)size);
231 		return -EROFS;
232 	}
233 
234 	folio_fill_tail(folio, 0, di->id2.i_data.id_data, size);
235 	folio_mark_uptodate(folio);
236 
237 	return 0;
238 }
239 
ocfs2_readpage_inline(struct inode * inode,struct folio * folio)240 static int ocfs2_readpage_inline(struct inode *inode, struct folio *folio)
241 {
242 	int ret;
243 	struct buffer_head *di_bh = NULL;
244 
245 	BUG_ON(!folio_test_locked(folio));
246 	BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
247 
248 	ret = ocfs2_read_inode_block(inode, &di_bh);
249 	if (ret) {
250 		mlog_errno(ret);
251 		goto out;
252 	}
253 
254 	ret = ocfs2_read_inline_data(inode, folio, di_bh);
255 out:
256 	folio_unlock(folio);
257 
258 	brelse(di_bh);
259 	return ret;
260 }
261 
ocfs2_read_folio(struct file * file,struct folio * folio)262 static int ocfs2_read_folio(struct file *file, struct folio *folio)
263 {
264 	struct inode *inode = folio->mapping->host;
265 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
266 	loff_t start = folio_pos(folio);
267 	int ret, unlock = 1;
268 
269 	trace_ocfs2_readpage((unsigned long long)oi->ip_blkno, folio->index);
270 
271 	ret = ocfs2_inode_lock_with_folio(inode, NULL, 0, folio);
272 	if (ret != 0) {
273 		if (ret == AOP_TRUNCATED_PAGE)
274 			unlock = 0;
275 		mlog_errno(ret);
276 		goto out;
277 	}
278 
279 	if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
280 		/*
281 		 * Unlock the folio and cycle ip_alloc_sem so that we don't
282 		 * busyloop waiting for ip_alloc_sem to unlock
283 		 */
284 		ret = AOP_TRUNCATED_PAGE;
285 		folio_unlock(folio);
286 		unlock = 0;
287 		down_read(&oi->ip_alloc_sem);
288 		up_read(&oi->ip_alloc_sem);
289 		goto out_inode_unlock;
290 	}
291 
292 	/*
293 	 * i_size might have just been updated as we grabbed the meta lock.  We
294 	 * might now be discovering a truncate that hit on another node.
295 	 * block_read_full_folio->get_block freaks out if it is asked to read
296 	 * beyond the end of a file, so we check here.  Callers
297 	 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
298 	 * and notice that the folio they just read isn't needed.
299 	 *
300 	 * XXX sys_readahead() seems to get that wrong?
301 	 */
302 	if (start >= i_size_read(inode)) {
303 		folio_zero_segment(folio, 0, folio_size(folio));
304 		folio_mark_uptodate(folio);
305 		ret = 0;
306 		goto out_alloc;
307 	}
308 
309 	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
310 		ret = ocfs2_readpage_inline(inode, folio);
311 	else
312 		ret = block_read_full_folio(folio, ocfs2_get_block);
313 	unlock = 0;
314 
315 out_alloc:
316 	up_read(&oi->ip_alloc_sem);
317 out_inode_unlock:
318 	ocfs2_inode_unlock(inode, 0);
319 out:
320 	if (unlock)
321 		folio_unlock(folio);
322 	return ret;
323 }
324 
325 /*
326  * This is used only for read-ahead. Failures or difficult to handle
327  * situations are safe to ignore.
328  *
329  * Right now, we don't bother with BH_Boundary - in-inode extent lists
330  * are quite large (243 extents on 4k blocks), so most inodes don't
331  * grow out to a tree. If need be, detecting boundary extents could
332  * trivially be added in a future version of ocfs2_get_block().
333  */
ocfs2_readahead(struct readahead_control * rac)334 static void ocfs2_readahead(struct readahead_control *rac)
335 {
336 	int ret;
337 	struct inode *inode = rac->mapping->host;
338 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
339 
340 	/*
341 	 * Use the nonblocking flag for the dlm code to avoid page
342 	 * lock inversion, but don't bother with retrying.
343 	 */
344 	ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
345 	if (ret)
346 		return;
347 
348 	if (down_read_trylock(&oi->ip_alloc_sem) == 0)
349 		goto out_unlock;
350 
351 	/*
352 	 * Don't bother with inline-data. There isn't anything
353 	 * to read-ahead in that case anyway...
354 	 */
355 	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
356 		goto out_up;
357 
358 	/*
359 	 * Check whether a remote node truncated this file - we just
360 	 * drop out in that case as it's not worth handling here.
361 	 */
362 	if (readahead_pos(rac) >= i_size_read(inode))
363 		goto out_up;
364 
365 	mpage_readahead(rac, ocfs2_get_block);
366 
367 out_up:
368 	up_read(&oi->ip_alloc_sem);
369 out_unlock:
370 	ocfs2_inode_unlock(inode, 0);
371 }
372 
373 /* Note: Because we don't support holes, our allocation has
374  * already happened (allocation writes zeros to the file data)
375  * so we don't have to worry about ordered writes in
376  * ocfs2_writepages.
377  *
378  * ->writepages is called during the process of invalidating the page cache
379  * during blocked lock processing.  It can't block on any cluster locks
380  * to during block mapping.  It's relying on the fact that the block
381  * mapping can't have disappeared under the dirty pages that it is
382  * being asked to write back.
383  */
ocfs2_writepages(struct address_space * mapping,struct writeback_control * wbc)384 static int ocfs2_writepages(struct address_space *mapping,
385 		struct writeback_control *wbc)
386 {
387 	return mpage_writepages(mapping, wbc, ocfs2_get_block);
388 }
389 
390 /* Taken from ext3. We don't necessarily need the full blown
391  * functionality yet, but IMHO it's better to cut and paste the whole
392  * thing so we can avoid introducing our own bugs (and easily pick up
393  * their fixes when they happen) --Mark */
walk_page_buffers(handle_t * handle,struct buffer_head * head,unsigned from,unsigned to,int * partial,int (* fn)(handle_t * handle,struct buffer_head * bh))394 int walk_page_buffers(	handle_t *handle,
395 			struct buffer_head *head,
396 			unsigned from,
397 			unsigned to,
398 			int *partial,
399 			int (*fn)(	handle_t *handle,
400 					struct buffer_head *bh))
401 {
402 	struct buffer_head *bh;
403 	unsigned block_start, block_end;
404 	unsigned blocksize = head->b_size;
405 	int err, ret = 0;
406 	struct buffer_head *next;
407 
408 	for (	bh = head, block_start = 0;
409 		ret == 0 && (bh != head || !block_start);
410 	    	block_start = block_end, bh = next)
411 	{
412 		next = bh->b_this_page;
413 		block_end = block_start + blocksize;
414 		if (block_end <= from || block_start >= to) {
415 			if (partial && !buffer_uptodate(bh))
416 				*partial = 1;
417 			continue;
418 		}
419 		err = (*fn)(handle, bh);
420 		if (!ret)
421 			ret = err;
422 	}
423 	return ret;
424 }
425 
ocfs2_bmap(struct address_space * mapping,sector_t block)426 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
427 {
428 	sector_t status;
429 	u64 p_blkno = 0;
430 	int err = 0;
431 	struct inode *inode = mapping->host;
432 
433 	trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno,
434 			 (unsigned long long)block);
435 
436 	/*
437 	 * The swap code (ab-)uses ->bmap to get a block mapping and then
438 	 * bypasseѕ the file system for actual I/O.  We really can't allow
439 	 * that on refcounted inodes, so we have to skip out here.  And yes,
440 	 * 0 is the magic code for a bmap error..
441 	 */
442 	if (ocfs2_is_refcount_inode(inode))
443 		return 0;
444 
445 	/* We don't need to lock journal system files, since they aren't
446 	 * accessed concurrently from multiple nodes.
447 	 */
448 	if (!INODE_JOURNAL(inode)) {
449 		err = ocfs2_inode_lock(inode, NULL, 0);
450 		if (err) {
451 			if (err != -ENOENT)
452 				mlog_errno(err);
453 			goto bail;
454 		}
455 		down_read(&OCFS2_I(inode)->ip_alloc_sem);
456 	}
457 
458 	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
459 		err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
460 						  NULL);
461 
462 	if (!INODE_JOURNAL(inode)) {
463 		up_read(&OCFS2_I(inode)->ip_alloc_sem);
464 		ocfs2_inode_unlock(inode, 0);
465 	}
466 
467 	if (err) {
468 		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
469 		     (unsigned long long)block);
470 		mlog_errno(err);
471 		goto bail;
472 	}
473 
474 bail:
475 	status = err ? 0 : p_blkno;
476 
477 	return status;
478 }
479 
ocfs2_release_folio(struct folio * folio,gfp_t wait)480 static bool ocfs2_release_folio(struct folio *folio, gfp_t wait)
481 {
482 	if (!folio_buffers(folio))
483 		return false;
484 	return try_to_free_buffers(folio);
485 }
486 
ocfs2_figure_cluster_boundaries(struct ocfs2_super * osb,u32 cpos,unsigned int * start,unsigned int * end)487 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
488 					    u32 cpos,
489 					    unsigned int *start,
490 					    unsigned int *end)
491 {
492 	unsigned int cluster_start = 0, cluster_end = PAGE_SIZE;
493 
494 	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits)) {
495 		unsigned int cpp;
496 
497 		cpp = 1 << (PAGE_SHIFT - osb->s_clustersize_bits);
498 
499 		cluster_start = cpos % cpp;
500 		cluster_start = cluster_start << osb->s_clustersize_bits;
501 
502 		cluster_end = cluster_start + osb->s_clustersize;
503 	}
504 
505 	BUG_ON(cluster_start > PAGE_SIZE);
506 	BUG_ON(cluster_end > PAGE_SIZE);
507 
508 	if (start)
509 		*start = cluster_start;
510 	if (end)
511 		*end = cluster_end;
512 }
513 
514 /*
515  * 'from' and 'to' are the region in the page to avoid zeroing.
516  *
517  * If pagesize > clustersize, this function will avoid zeroing outside
518  * of the cluster boundary.
519  *
520  * from == to == 0 is code for "zero the entire cluster region"
521  */
ocfs2_clear_folio_regions(struct folio * folio,struct ocfs2_super * osb,u32 cpos,unsigned from,unsigned to)522 static void ocfs2_clear_folio_regions(struct folio *folio,
523 				     struct ocfs2_super *osb, u32 cpos,
524 				     unsigned from, unsigned to)
525 {
526 	void *kaddr;
527 	unsigned int cluster_start, cluster_end;
528 
529 	ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
530 
531 	kaddr = kmap_local_folio(folio, 0);
532 
533 	if (from || to) {
534 		if (from > cluster_start)
535 			memset(kaddr + cluster_start, 0, from - cluster_start);
536 		if (to < cluster_end)
537 			memset(kaddr + to, 0, cluster_end - to);
538 	} else {
539 		memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
540 	}
541 
542 	kunmap_local(kaddr);
543 }
544 
545 /*
546  * Nonsparse file systems fully allocate before we get to the write
547  * code. This prevents ocfs2_write() from tagging the write as an
548  * allocating one, which means ocfs2_map_folio_blocks() might try to
549  * read-in the blocks at the tail of our file. Avoid reading them by
550  * testing i_size against each block offset.
551  */
ocfs2_should_read_blk(struct inode * inode,struct folio * folio,unsigned int block_start)552 static int ocfs2_should_read_blk(struct inode *inode, struct folio *folio,
553 				 unsigned int block_start)
554 {
555 	u64 offset = folio_pos(folio) + block_start;
556 
557 	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
558 		return 1;
559 
560 	if (i_size_read(inode) > offset)
561 		return 1;
562 
563 	return 0;
564 }
565 
566 /*
567  * Some of this taken from __block_write_begin(). We already have our
568  * mapping by now though, and the entire write will be allocating or
569  * it won't, so not much need to use BH_New.
570  *
571  * This will also skip zeroing, which is handled externally.
572  */
ocfs2_map_folio_blocks(struct folio * folio,u64 * p_blkno,struct inode * inode,unsigned int from,unsigned int to,int new)573 int ocfs2_map_folio_blocks(struct folio *folio, u64 *p_blkno,
574 			  struct inode *inode, unsigned int from,
575 			  unsigned int to, int new)
576 {
577 	int ret = 0;
578 	struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
579 	unsigned int block_end, block_start;
580 	unsigned int bsize = i_blocksize(inode);
581 
582 	head = folio_buffers(folio);
583 	if (!head)
584 		head = create_empty_buffers(folio, bsize, 0);
585 
586 	for (bh = head, block_start = 0; bh != head || !block_start;
587 	     bh = bh->b_this_page, block_start += bsize) {
588 		block_end = block_start + bsize;
589 
590 		clear_buffer_new(bh);
591 
592 		/*
593 		 * Ignore blocks outside of our i/o range -
594 		 * they may belong to unallocated clusters.
595 		 */
596 		if (block_start >= to || block_end <= from) {
597 			if (folio_test_uptodate(folio))
598 				set_buffer_uptodate(bh);
599 			continue;
600 		}
601 
602 		/*
603 		 * For an allocating write with cluster size >= page
604 		 * size, we always write the entire page.
605 		 */
606 		if (new)
607 			set_buffer_new(bh);
608 
609 		if (!buffer_mapped(bh)) {
610 			map_bh(bh, inode->i_sb, *p_blkno);
611 			clean_bdev_bh_alias(bh);
612 		}
613 
614 		if (folio_test_uptodate(folio)) {
615 			set_buffer_uptodate(bh);
616 		} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
617 			   !buffer_new(bh) &&
618 			   ocfs2_should_read_blk(inode, folio, block_start) &&
619 			   (block_start < from || block_end > to)) {
620 			bh_read_nowait(bh, 0);
621 			*wait_bh++=bh;
622 		}
623 
624 		*p_blkno = *p_blkno + 1;
625 	}
626 
627 	/*
628 	 * If we issued read requests - let them complete.
629 	 */
630 	while(wait_bh > wait) {
631 		wait_on_buffer(*--wait_bh);
632 		if (!buffer_uptodate(*wait_bh))
633 			ret = -EIO;
634 	}
635 
636 	if (ret == 0 || !new)
637 		return ret;
638 
639 	/*
640 	 * If we get -EIO above, zero out any newly allocated blocks
641 	 * to avoid exposing stale data.
642 	 */
643 	bh = head;
644 	block_start = 0;
645 	do {
646 		block_end = block_start + bsize;
647 		if (block_end <= from)
648 			goto next_bh;
649 		if (block_start >= to)
650 			break;
651 
652 		folio_zero_range(folio, block_start, bh->b_size);
653 		set_buffer_uptodate(bh);
654 		mark_buffer_dirty(bh);
655 
656 next_bh:
657 		block_start = block_end;
658 		bh = bh->b_this_page;
659 	} while (bh != head);
660 
661 	return ret;
662 }
663 
664 #if (PAGE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
665 #define OCFS2_MAX_CTXT_PAGES	1
666 #else
667 #define OCFS2_MAX_CTXT_PAGES	(OCFS2_MAX_CLUSTERSIZE / PAGE_SIZE)
668 #endif
669 
670 #define OCFS2_MAX_CLUSTERS_PER_PAGE	(PAGE_SIZE / OCFS2_MIN_CLUSTERSIZE)
671 
672 struct ocfs2_unwritten_extent {
673 	struct list_head	ue_node;
674 	struct list_head	ue_ip_node;
675 	u32			ue_cpos;
676 	u32			ue_phys;
677 };
678 
679 /*
680  * Describe the state of a single cluster to be written to.
681  */
682 struct ocfs2_write_cluster_desc {
683 	u32		c_cpos;
684 	u32		c_phys;
685 	/*
686 	 * Give this a unique field because c_phys eventually gets
687 	 * filled.
688 	 */
689 	unsigned	c_new;
690 	unsigned	c_clear_unwritten;
691 	unsigned	c_needs_zero;
692 };
693 
694 struct ocfs2_write_ctxt {
695 	/* Logical cluster position / len of write */
696 	u32				w_cpos;
697 	u32				w_clen;
698 
699 	/* First cluster allocated in a nonsparse extend */
700 	u32				w_first_new_cpos;
701 
702 	/* Type of caller. Must be one of buffer, mmap, direct.  */
703 	ocfs2_write_type_t		w_type;
704 
705 	struct ocfs2_write_cluster_desc	w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
706 
707 	/*
708 	 * This is true if page_size > cluster_size.
709 	 *
710 	 * It triggers a set of special cases during write which might
711 	 * have to deal with allocating writes to partial pages.
712 	 */
713 	unsigned int			w_large_pages;
714 
715 	/*
716 	 * Folios involved in this write.
717 	 *
718 	 * w_target_folio is the folio being written to by the user.
719 	 *
720 	 * w_folios is an array of folios which always contains
721 	 * w_target_folio, and in the case of an allocating write with
722 	 * page_size < cluster size, it will contain zero'd and mapped
723 	 * pages adjacent to w_target_folio which need to be written
724 	 * out in so that future reads from that region will get
725 	 * zero's.
726 	 */
727 	unsigned int			w_num_folios;
728 	struct folio			*w_folios[OCFS2_MAX_CTXT_PAGES];
729 	struct folio			*w_target_folio;
730 
731 	/*
732 	 * w_target_locked is used for page_mkwrite path indicating no unlocking
733 	 * against w_target_folio in ocfs2_write_end_nolock.
734 	 */
735 	unsigned int			w_target_locked:1;
736 
737 	/*
738 	 * ocfs2_write_end() uses this to know what the real range to
739 	 * write in the target should be.
740 	 */
741 	unsigned int			w_target_from;
742 	unsigned int			w_target_to;
743 
744 	/*
745 	 * We could use journal_current_handle() but this is cleaner,
746 	 * IMHO -Mark
747 	 */
748 	handle_t			*w_handle;
749 
750 	struct buffer_head		*w_di_bh;
751 
752 	struct ocfs2_cached_dealloc_ctxt w_dealloc;
753 
754 	struct list_head		w_unwritten_list;
755 	unsigned int			w_unwritten_count;
756 };
757 
ocfs2_unlock_and_free_folios(struct folio ** folios,int num_folios)758 void ocfs2_unlock_and_free_folios(struct folio **folios, int num_folios)
759 {
760 	int i;
761 
762 	for(i = 0; i < num_folios; i++) {
763 		if (!folios[i])
764 			continue;
765 		folio_unlock(folios[i]);
766 		folio_mark_accessed(folios[i]);
767 		folio_put(folios[i]);
768 	}
769 }
770 
ocfs2_unlock_folios(struct ocfs2_write_ctxt * wc)771 static void ocfs2_unlock_folios(struct ocfs2_write_ctxt *wc)
772 {
773 	int i;
774 
775 	/*
776 	 * w_target_locked is only set to true in the page_mkwrite() case.
777 	 * The intent is to allow us to lock the target page from write_begin()
778 	 * to write_end(). The caller must hold a ref on w_target_folio.
779 	 */
780 	if (wc->w_target_locked) {
781 		BUG_ON(!wc->w_target_folio);
782 		for (i = 0; i < wc->w_num_folios; i++) {
783 			if (wc->w_target_folio == wc->w_folios[i]) {
784 				wc->w_folios[i] = NULL;
785 				break;
786 			}
787 		}
788 		folio_mark_accessed(wc->w_target_folio);
789 		folio_put(wc->w_target_folio);
790 	}
791 	ocfs2_unlock_and_free_folios(wc->w_folios, wc->w_num_folios);
792 }
793 
ocfs2_free_unwritten_list(struct inode * inode,struct list_head * head)794 static void ocfs2_free_unwritten_list(struct inode *inode,
795 				 struct list_head *head)
796 {
797 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
798 	struct ocfs2_unwritten_extent *ue = NULL, *tmp = NULL;
799 
800 	list_for_each_entry_safe(ue, tmp, head, ue_node) {
801 		list_del(&ue->ue_node);
802 		spin_lock(&oi->ip_lock);
803 		list_del(&ue->ue_ip_node);
804 		spin_unlock(&oi->ip_lock);
805 		kfree(ue);
806 	}
807 }
808 
ocfs2_free_write_ctxt(struct inode * inode,struct ocfs2_write_ctxt * wc)809 static void ocfs2_free_write_ctxt(struct inode *inode,
810 				  struct ocfs2_write_ctxt *wc)
811 {
812 	ocfs2_free_unwritten_list(inode, &wc->w_unwritten_list);
813 	ocfs2_unlock_folios(wc);
814 	brelse(wc->w_di_bh);
815 	kfree(wc);
816 }
817 
ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt ** wcp,struct ocfs2_super * osb,loff_t pos,unsigned len,ocfs2_write_type_t type,struct buffer_head * di_bh)818 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
819 				  struct ocfs2_super *osb, loff_t pos,
820 				  unsigned len, ocfs2_write_type_t type,
821 				  struct buffer_head *di_bh)
822 {
823 	u32 cend;
824 	struct ocfs2_write_ctxt *wc;
825 
826 	wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
827 	if (!wc)
828 		return -ENOMEM;
829 
830 	wc->w_cpos = pos >> osb->s_clustersize_bits;
831 	wc->w_first_new_cpos = UINT_MAX;
832 	cend = (pos + len - 1) >> osb->s_clustersize_bits;
833 	wc->w_clen = cend - wc->w_cpos + 1;
834 	get_bh(di_bh);
835 	wc->w_di_bh = di_bh;
836 	wc->w_type = type;
837 
838 	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits))
839 		wc->w_large_pages = 1;
840 	else
841 		wc->w_large_pages = 0;
842 
843 	ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
844 	INIT_LIST_HEAD(&wc->w_unwritten_list);
845 
846 	*wcp = wc;
847 
848 	return 0;
849 }
850 
851 /*
852  * If a page has any new buffers, zero them out here, and mark them uptodate
853  * and dirty so they'll be written out (in order to prevent uninitialised
854  * block data from leaking). And clear the new bit.
855  */
ocfs2_zero_new_buffers(struct folio * folio,size_t from,size_t to)856 static void ocfs2_zero_new_buffers(struct folio *folio, size_t from, size_t to)
857 {
858 	unsigned int block_start, block_end;
859 	struct buffer_head *head, *bh;
860 
861 	BUG_ON(!folio_test_locked(folio));
862 	head = folio_buffers(folio);
863 	if (!head)
864 		return;
865 
866 	bh = head;
867 	block_start = 0;
868 	do {
869 		block_end = block_start + bh->b_size;
870 
871 		if (buffer_new(bh)) {
872 			if (block_end > from && block_start < to) {
873 				if (!folio_test_uptodate(folio)) {
874 					unsigned start, end;
875 
876 					start = max(from, block_start);
877 					end = min(to, block_end);
878 
879 					folio_zero_segment(folio, start, end);
880 					set_buffer_uptodate(bh);
881 				}
882 
883 				clear_buffer_new(bh);
884 				mark_buffer_dirty(bh);
885 			}
886 		}
887 
888 		block_start = block_end;
889 		bh = bh->b_this_page;
890 	} while (bh != head);
891 }
892 
893 /*
894  * Only called when we have a failure during allocating write to write
895  * zero's to the newly allocated region.
896  */
ocfs2_write_failure(struct inode * inode,struct ocfs2_write_ctxt * wc,loff_t user_pos,unsigned user_len)897 static void ocfs2_write_failure(struct inode *inode,
898 				struct ocfs2_write_ctxt *wc,
899 				loff_t user_pos, unsigned user_len)
900 {
901 	int i;
902 	unsigned from = user_pos & (PAGE_SIZE - 1),
903 		to = user_pos + user_len;
904 
905 	if (wc->w_target_folio)
906 		ocfs2_zero_new_buffers(wc->w_target_folio, from, to);
907 
908 	for (i = 0; i < wc->w_num_folios; i++) {
909 		struct folio *folio = wc->w_folios[i];
910 
911 		if (folio && folio_buffers(folio)) {
912 			if (ocfs2_should_order_data(inode))
913 				ocfs2_jbd2_inode_add_write(wc->w_handle, inode,
914 							   user_pos, user_len);
915 
916 			block_commit_write(folio, from, to);
917 		}
918 	}
919 }
920 
ocfs2_prepare_folio_for_write(struct inode * inode,u64 * p_blkno,struct ocfs2_write_ctxt * wc,struct folio * folio,u32 cpos,loff_t user_pos,unsigned user_len,int new)921 static int ocfs2_prepare_folio_for_write(struct inode *inode, u64 *p_blkno,
922 		struct ocfs2_write_ctxt *wc, struct folio *folio, u32 cpos,
923 		loff_t user_pos, unsigned user_len, int new)
924 {
925 	int ret;
926 	unsigned int map_from = 0, map_to = 0;
927 	unsigned int cluster_start, cluster_end;
928 	unsigned int user_data_from = 0, user_data_to = 0;
929 
930 	ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
931 					&cluster_start, &cluster_end);
932 
933 	/* treat the write as new if the a hole/lseek spanned across
934 	 * the page boundary.
935 	 */
936 	new = new | ((i_size_read(inode) <= folio_pos(folio)) &&
937 			(folio_pos(folio) <= user_pos));
938 
939 	if (folio == wc->w_target_folio) {
940 		map_from = user_pos & (PAGE_SIZE - 1);
941 		map_to = map_from + user_len;
942 
943 		if (new)
944 			ret = ocfs2_map_folio_blocks(folio, p_blkno, inode,
945 					cluster_start, cluster_end, new);
946 		else
947 			ret = ocfs2_map_folio_blocks(folio, p_blkno, inode,
948 					map_from, map_to, new);
949 		if (ret) {
950 			mlog_errno(ret);
951 			goto out;
952 		}
953 
954 		user_data_from = map_from;
955 		user_data_to = map_to;
956 		if (new) {
957 			map_from = cluster_start;
958 			map_to = cluster_end;
959 		}
960 	} else {
961 		/*
962 		 * If we haven't allocated the new folio yet, we
963 		 * shouldn't be writing it out without copying user
964 		 * data. This is likely a math error from the caller.
965 		 */
966 		BUG_ON(!new);
967 
968 		map_from = cluster_start;
969 		map_to = cluster_end;
970 
971 		ret = ocfs2_map_folio_blocks(folio, p_blkno, inode,
972 				cluster_start, cluster_end, new);
973 		if (ret) {
974 			mlog_errno(ret);
975 			goto out;
976 		}
977 	}
978 
979 	/*
980 	 * Parts of newly allocated folios need to be zero'd.
981 	 *
982 	 * Above, we have also rewritten 'to' and 'from' - as far as
983 	 * the rest of the function is concerned, the entire cluster
984 	 * range inside of a folio needs to be written.
985 	 *
986 	 * We can skip this if the folio is uptodate - it's already
987 	 * been zero'd from being read in as a hole.
988 	 */
989 	if (new && !folio_test_uptodate(folio))
990 		ocfs2_clear_folio_regions(folio, OCFS2_SB(inode->i_sb),
991 					 cpos, user_data_from, user_data_to);
992 
993 	flush_dcache_folio(folio);
994 
995 out:
996 	return ret;
997 }
998 
999 /*
1000  * This function will only grab one clusters worth of pages.
1001  */
ocfs2_grab_folios_for_write(struct address_space * mapping,struct ocfs2_write_ctxt * wc,u32 cpos,loff_t user_pos,unsigned user_len,int new,struct folio * mmap_folio)1002 static int ocfs2_grab_folios_for_write(struct address_space *mapping,
1003 		struct ocfs2_write_ctxt *wc, u32 cpos, loff_t user_pos,
1004 		unsigned user_len, int new, struct folio *mmap_folio)
1005 {
1006 	int ret = 0, i;
1007 	unsigned long start, target_index, end_index, index;
1008 	struct inode *inode = mapping->host;
1009 	loff_t last_byte;
1010 
1011 	target_index = user_pos >> PAGE_SHIFT;
1012 
1013 	/*
1014 	 * Figure out how many pages we'll be manipulating here. For
1015 	 * non allocating write, we just change the one
1016 	 * page. Otherwise, we'll need a whole clusters worth.  If we're
1017 	 * writing past i_size, we only need enough pages to cover the
1018 	 * last page of the write.
1019 	 */
1020 	if (new) {
1021 		wc->w_num_folios = ocfs2_pages_per_cluster(inode->i_sb);
1022 		start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1023 		/*
1024 		 * We need the index *past* the last page we could possibly
1025 		 * touch.  This is the page past the end of the write or
1026 		 * i_size, whichever is greater.
1027 		 */
1028 		last_byte = max(user_pos + user_len, i_size_read(inode));
1029 		BUG_ON(last_byte < 1);
1030 		end_index = ((last_byte - 1) >> PAGE_SHIFT) + 1;
1031 		if ((start + wc->w_num_folios) > end_index)
1032 			wc->w_num_folios = end_index - start;
1033 	} else {
1034 		wc->w_num_folios = 1;
1035 		start = target_index;
1036 	}
1037 	end_index = (user_pos + user_len - 1) >> PAGE_SHIFT;
1038 
1039 	for(i = 0; i < wc->w_num_folios; i++) {
1040 		index = start + i;
1041 
1042 		if (index >= target_index && index <= end_index &&
1043 		    wc->w_type == OCFS2_WRITE_MMAP) {
1044 			/*
1045 			 * ocfs2_pagemkwrite() is a little different
1046 			 * and wants us to directly use the page
1047 			 * passed in.
1048 			 */
1049 			folio_lock(mmap_folio);
1050 
1051 			/* Exit and let the caller retry */
1052 			if (mmap_folio->mapping != mapping) {
1053 				WARN_ON(mmap_folio->mapping);
1054 				folio_unlock(mmap_folio);
1055 				ret = -EAGAIN;
1056 				goto out;
1057 			}
1058 
1059 			folio_get(mmap_folio);
1060 			wc->w_folios[i] = mmap_folio;
1061 			wc->w_target_locked = true;
1062 		} else if (index >= target_index && index <= end_index &&
1063 			   wc->w_type == OCFS2_WRITE_DIRECT) {
1064 			/* Direct write has no mapping page. */
1065 			wc->w_folios[i] = NULL;
1066 			continue;
1067 		} else {
1068 			wc->w_folios[i] = __filemap_get_folio(mapping, index,
1069 					FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
1070 					GFP_NOFS);
1071 			if (IS_ERR(wc->w_folios[i])) {
1072 				ret = PTR_ERR(wc->w_folios[i]);
1073 				mlog_errno(ret);
1074 				goto out;
1075 			}
1076 		}
1077 		folio_wait_stable(wc->w_folios[i]);
1078 
1079 		if (index == target_index)
1080 			wc->w_target_folio = wc->w_folios[i];
1081 	}
1082 out:
1083 	if (ret)
1084 		wc->w_target_locked = false;
1085 	return ret;
1086 }
1087 
1088 /*
1089  * Prepare a single cluster for write one cluster into the file.
1090  */
ocfs2_write_cluster(struct address_space * mapping,u32 * phys,unsigned int new,unsigned int clear_unwritten,unsigned int should_zero,struct ocfs2_alloc_context * data_ac,struct ocfs2_alloc_context * meta_ac,struct ocfs2_write_ctxt * wc,u32 cpos,loff_t user_pos,unsigned user_len)1091 static int ocfs2_write_cluster(struct address_space *mapping,
1092 			       u32 *phys, unsigned int new,
1093 			       unsigned int clear_unwritten,
1094 			       unsigned int should_zero,
1095 			       struct ocfs2_alloc_context *data_ac,
1096 			       struct ocfs2_alloc_context *meta_ac,
1097 			       struct ocfs2_write_ctxt *wc, u32 cpos,
1098 			       loff_t user_pos, unsigned user_len)
1099 {
1100 	int ret, i;
1101 	u64 p_blkno;
1102 	struct inode *inode = mapping->host;
1103 	struct ocfs2_extent_tree et;
1104 	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
1105 
1106 	if (new) {
1107 		u32 tmp_pos;
1108 
1109 		/*
1110 		 * This is safe to call with the page locks - it won't take
1111 		 * any additional semaphores or cluster locks.
1112 		 */
1113 		tmp_pos = cpos;
1114 		ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1115 					   &tmp_pos, 1, !clear_unwritten,
1116 					   wc->w_di_bh, wc->w_handle,
1117 					   data_ac, meta_ac, NULL);
1118 		/*
1119 		 * This shouldn't happen because we must have already
1120 		 * calculated the correct meta data allocation required. The
1121 		 * internal tree allocation code should know how to increase
1122 		 * transaction credits itself.
1123 		 *
1124 		 * If need be, we could handle -EAGAIN for a
1125 		 * RESTART_TRANS here.
1126 		 */
1127 		mlog_bug_on_msg(ret == -EAGAIN,
1128 				"Inode %llu: EAGAIN return during allocation.\n",
1129 				(unsigned long long)OCFS2_I(inode)->ip_blkno);
1130 		if (ret < 0) {
1131 			mlog_errno(ret);
1132 			goto out;
1133 		}
1134 	} else if (clear_unwritten) {
1135 		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1136 					      wc->w_di_bh);
1137 		ret = ocfs2_mark_extent_written(inode, &et,
1138 						wc->w_handle, cpos, 1, *phys,
1139 						meta_ac, &wc->w_dealloc);
1140 		if (ret < 0) {
1141 			mlog_errno(ret);
1142 			goto out;
1143 		}
1144 	}
1145 
1146 	/*
1147 	 * The only reason this should fail is due to an inability to
1148 	 * find the extent added.
1149 	 */
1150 	ret = ocfs2_get_clusters(inode, cpos, phys, NULL, NULL);
1151 	if (ret < 0) {
1152 		mlog(ML_ERROR, "Get physical blkno failed for inode %llu, "
1153 			    "at logical cluster %u",
1154 			    (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos);
1155 		goto out;
1156 	}
1157 
1158 	BUG_ON(*phys == 0);
1159 
1160 	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, *phys);
1161 	if (!should_zero)
1162 		p_blkno += (user_pos >> inode->i_sb->s_blocksize_bits) & (u64)(bpc - 1);
1163 
1164 	for (i = 0; i < wc->w_num_folios; i++) {
1165 		int tmpret;
1166 
1167 		/* This is the direct io target page. */
1168 		if (wc->w_folios[i] == NULL) {
1169 			p_blkno += (1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits));
1170 			continue;
1171 		}
1172 
1173 		tmpret = ocfs2_prepare_folio_for_write(inode, &p_blkno, wc,
1174 				wc->w_folios[i], cpos, user_pos, user_len,
1175 				should_zero);
1176 		if (tmpret) {
1177 			mlog_errno(tmpret);
1178 			if (ret == 0)
1179 				ret = tmpret;
1180 		}
1181 	}
1182 
1183 	/*
1184 	 * We only have cleanup to do in case of allocating write.
1185 	 */
1186 	if (ret && new)
1187 		ocfs2_write_failure(inode, wc, user_pos, user_len);
1188 
1189 out:
1190 
1191 	return ret;
1192 }
1193 
ocfs2_write_cluster_by_desc(struct address_space * mapping,struct ocfs2_alloc_context * data_ac,struct ocfs2_alloc_context * meta_ac,struct ocfs2_write_ctxt * wc,loff_t pos,unsigned len)1194 static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1195 				       struct ocfs2_alloc_context *data_ac,
1196 				       struct ocfs2_alloc_context *meta_ac,
1197 				       struct ocfs2_write_ctxt *wc,
1198 				       loff_t pos, unsigned len)
1199 {
1200 	int ret, i;
1201 	loff_t cluster_off;
1202 	unsigned int local_len = len;
1203 	struct ocfs2_write_cluster_desc *desc;
1204 	struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1205 
1206 	for (i = 0; i < wc->w_clen; i++) {
1207 		desc = &wc->w_desc[i];
1208 
1209 		/*
1210 		 * We have to make sure that the total write passed in
1211 		 * doesn't extend past a single cluster.
1212 		 */
1213 		local_len = len;
1214 		cluster_off = pos & (osb->s_clustersize - 1);
1215 		if ((cluster_off + local_len) > osb->s_clustersize)
1216 			local_len = osb->s_clustersize - cluster_off;
1217 
1218 		ret = ocfs2_write_cluster(mapping, &desc->c_phys,
1219 					  desc->c_new,
1220 					  desc->c_clear_unwritten,
1221 					  desc->c_needs_zero,
1222 					  data_ac, meta_ac,
1223 					  wc, desc->c_cpos, pos, local_len);
1224 		if (ret) {
1225 			mlog_errno(ret);
1226 			goto out;
1227 		}
1228 
1229 		len -= local_len;
1230 		pos += local_len;
1231 	}
1232 
1233 	ret = 0;
1234 out:
1235 	return ret;
1236 }
1237 
1238 /*
1239  * ocfs2_write_end() wants to know which parts of the target page it
1240  * should complete the write on. It's easiest to compute them ahead of
1241  * time when a more complete view of the write is available.
1242  */
ocfs2_set_target_boundaries(struct ocfs2_super * osb,struct ocfs2_write_ctxt * wc,loff_t pos,unsigned len,int alloc)1243 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1244 					struct ocfs2_write_ctxt *wc,
1245 					loff_t pos, unsigned len, int alloc)
1246 {
1247 	struct ocfs2_write_cluster_desc *desc;
1248 
1249 	wc->w_target_from = pos & (PAGE_SIZE - 1);
1250 	wc->w_target_to = wc->w_target_from + len;
1251 
1252 	if (alloc == 0)
1253 		return;
1254 
1255 	/*
1256 	 * Allocating write - we may have different boundaries based
1257 	 * on page size and cluster size.
1258 	 *
1259 	 * NOTE: We can no longer compute one value from the other as
1260 	 * the actual write length and user provided length may be
1261 	 * different.
1262 	 */
1263 
1264 	if (wc->w_large_pages) {
1265 		/*
1266 		 * We only care about the 1st and last cluster within
1267 		 * our range and whether they should be zero'd or not. Either
1268 		 * value may be extended out to the start/end of a
1269 		 * newly allocated cluster.
1270 		 */
1271 		desc = &wc->w_desc[0];
1272 		if (desc->c_needs_zero)
1273 			ocfs2_figure_cluster_boundaries(osb,
1274 							desc->c_cpos,
1275 							&wc->w_target_from,
1276 							NULL);
1277 
1278 		desc = &wc->w_desc[wc->w_clen - 1];
1279 		if (desc->c_needs_zero)
1280 			ocfs2_figure_cluster_boundaries(osb,
1281 							desc->c_cpos,
1282 							NULL,
1283 							&wc->w_target_to);
1284 	} else {
1285 		wc->w_target_from = 0;
1286 		wc->w_target_to = PAGE_SIZE;
1287 	}
1288 }
1289 
1290 /*
1291  * Check if this extent is marked UNWRITTEN by direct io. If so, we need not to
1292  * do the zero work. And should not to clear UNWRITTEN since it will be cleared
1293  * by the direct io procedure.
1294  * If this is a new extent that allocated by direct io, we should mark it in
1295  * the ip_unwritten_list.
1296  */
ocfs2_unwritten_check(struct inode * inode,struct ocfs2_write_ctxt * wc,struct ocfs2_write_cluster_desc * desc)1297 static int ocfs2_unwritten_check(struct inode *inode,
1298 				 struct ocfs2_write_ctxt *wc,
1299 				 struct ocfs2_write_cluster_desc *desc)
1300 {
1301 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1302 	struct ocfs2_unwritten_extent *ue = NULL, *new = NULL;
1303 	int ret = 0;
1304 
1305 	if (!desc->c_needs_zero)
1306 		return 0;
1307 
1308 retry:
1309 	spin_lock(&oi->ip_lock);
1310 	/* Needs not to zero no metter buffer or direct. The one who is zero
1311 	 * the cluster is doing zero. And he will clear unwritten after all
1312 	 * cluster io finished. */
1313 	list_for_each_entry(ue, &oi->ip_unwritten_list, ue_ip_node) {
1314 		if (desc->c_cpos == ue->ue_cpos) {
1315 			BUG_ON(desc->c_new);
1316 			desc->c_needs_zero = 0;
1317 			desc->c_clear_unwritten = 0;
1318 			goto unlock;
1319 		}
1320 	}
1321 
1322 	if (wc->w_type != OCFS2_WRITE_DIRECT)
1323 		goto unlock;
1324 
1325 	if (new == NULL) {
1326 		spin_unlock(&oi->ip_lock);
1327 		new = kmalloc(sizeof(struct ocfs2_unwritten_extent),
1328 			     GFP_NOFS);
1329 		if (new == NULL) {
1330 			ret = -ENOMEM;
1331 			goto out;
1332 		}
1333 		goto retry;
1334 	}
1335 	/* This direct write will doing zero. */
1336 	new->ue_cpos = desc->c_cpos;
1337 	new->ue_phys = desc->c_phys;
1338 	desc->c_clear_unwritten = 0;
1339 	list_add_tail(&new->ue_ip_node, &oi->ip_unwritten_list);
1340 	list_add_tail(&new->ue_node, &wc->w_unwritten_list);
1341 	wc->w_unwritten_count++;
1342 	new = NULL;
1343 unlock:
1344 	spin_unlock(&oi->ip_lock);
1345 out:
1346 	kfree(new);
1347 	return ret;
1348 }
1349 
1350 /*
1351  * Populate each single-cluster write descriptor in the write context
1352  * with information about the i/o to be done.
1353  *
1354  * Returns the number of clusters that will have to be allocated, as
1355  * well as a worst case estimate of the number of extent records that
1356  * would have to be created during a write to an unwritten region.
1357  */
ocfs2_populate_write_desc(struct inode * inode,struct ocfs2_write_ctxt * wc,unsigned int * clusters_to_alloc,unsigned int * extents_to_split)1358 static int ocfs2_populate_write_desc(struct inode *inode,
1359 				     struct ocfs2_write_ctxt *wc,
1360 				     unsigned int *clusters_to_alloc,
1361 				     unsigned int *extents_to_split)
1362 {
1363 	int ret;
1364 	struct ocfs2_write_cluster_desc *desc;
1365 	unsigned int num_clusters = 0;
1366 	unsigned int ext_flags = 0;
1367 	u32 phys = 0;
1368 	int i;
1369 
1370 	*clusters_to_alloc = 0;
1371 	*extents_to_split = 0;
1372 
1373 	for (i = 0; i < wc->w_clen; i++) {
1374 		desc = &wc->w_desc[i];
1375 		desc->c_cpos = wc->w_cpos + i;
1376 
1377 		if (num_clusters == 0) {
1378 			/*
1379 			 * Need to look up the next extent record.
1380 			 */
1381 			ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1382 						 &num_clusters, &ext_flags);
1383 			if (ret) {
1384 				mlog_errno(ret);
1385 				goto out;
1386 			}
1387 
1388 			/* We should already CoW the refcountd extent. */
1389 			BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1390 
1391 			/*
1392 			 * Assume worst case - that we're writing in
1393 			 * the middle of the extent.
1394 			 *
1395 			 * We can assume that the write proceeds from
1396 			 * left to right, in which case the extent
1397 			 * insert code is smart enough to coalesce the
1398 			 * next splits into the previous records created.
1399 			 */
1400 			if (ext_flags & OCFS2_EXT_UNWRITTEN)
1401 				*extents_to_split = *extents_to_split + 2;
1402 		} else if (phys) {
1403 			/*
1404 			 * Only increment phys if it doesn't describe
1405 			 * a hole.
1406 			 */
1407 			phys++;
1408 		}
1409 
1410 		/*
1411 		 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1412 		 * file that got extended.  w_first_new_cpos tells us
1413 		 * where the newly allocated clusters are so we can
1414 		 * zero them.
1415 		 */
1416 		if (desc->c_cpos >= wc->w_first_new_cpos) {
1417 			BUG_ON(phys == 0);
1418 			desc->c_needs_zero = 1;
1419 		}
1420 
1421 		desc->c_phys = phys;
1422 		if (phys == 0) {
1423 			desc->c_new = 1;
1424 			desc->c_needs_zero = 1;
1425 			desc->c_clear_unwritten = 1;
1426 			*clusters_to_alloc = *clusters_to_alloc + 1;
1427 		}
1428 
1429 		if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1430 			desc->c_clear_unwritten = 1;
1431 			desc->c_needs_zero = 1;
1432 		}
1433 
1434 		ret = ocfs2_unwritten_check(inode, wc, desc);
1435 		if (ret) {
1436 			mlog_errno(ret);
1437 			goto out;
1438 		}
1439 
1440 		num_clusters--;
1441 	}
1442 
1443 	ret = 0;
1444 out:
1445 	return ret;
1446 }
1447 
ocfs2_write_begin_inline(struct address_space * mapping,struct inode * inode,struct ocfs2_write_ctxt * wc)1448 static int ocfs2_write_begin_inline(struct address_space *mapping,
1449 				    struct inode *inode,
1450 				    struct ocfs2_write_ctxt *wc)
1451 {
1452 	int ret;
1453 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1454 	struct folio *folio;
1455 	handle_t *handle;
1456 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1457 
1458 	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1459 	if (IS_ERR(handle)) {
1460 		ret = PTR_ERR(handle);
1461 		mlog_errno(ret);
1462 		goto out;
1463 	}
1464 
1465 	folio = __filemap_get_folio(mapping, 0,
1466 			FGP_LOCK | FGP_ACCESSED | FGP_CREAT, GFP_NOFS);
1467 	if (IS_ERR(folio)) {
1468 		ocfs2_commit_trans(osb, handle);
1469 		ret = PTR_ERR(folio);
1470 		mlog_errno(ret);
1471 		goto out;
1472 	}
1473 	/*
1474 	 * If we don't set w_num_folios then this folio won't get unlocked
1475 	 * and freed on cleanup of the write context.
1476 	 */
1477 	wc->w_target_folio = folio;
1478 	wc->w_folios[0] = folio;
1479 	wc->w_num_folios = 1;
1480 
1481 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1482 				      OCFS2_JOURNAL_ACCESS_WRITE);
1483 	if (ret) {
1484 		ocfs2_commit_trans(osb, handle);
1485 
1486 		mlog_errno(ret);
1487 		goto out;
1488 	}
1489 
1490 	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1491 		ocfs2_set_inode_data_inline(inode, di);
1492 
1493 	if (!folio_test_uptodate(folio)) {
1494 		ret = ocfs2_read_inline_data(inode, folio, wc->w_di_bh);
1495 		if (ret) {
1496 			ocfs2_commit_trans(osb, handle);
1497 
1498 			goto out;
1499 		}
1500 	}
1501 
1502 	wc->w_handle = handle;
1503 out:
1504 	return ret;
1505 }
1506 
ocfs2_size_fits_inline_data(struct buffer_head * di_bh,u64 new_size)1507 int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1508 {
1509 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1510 
1511 	if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1512 		return 1;
1513 	return 0;
1514 }
1515 
ocfs2_try_to_write_inline_data(struct address_space * mapping,struct inode * inode,loff_t pos,size_t len,struct folio * mmap_folio,struct ocfs2_write_ctxt * wc)1516 static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1517 		struct inode *inode, loff_t pos, size_t len,
1518 		struct folio *mmap_folio, struct ocfs2_write_ctxt *wc)
1519 {
1520 	int ret, written = 0;
1521 	loff_t end = pos + len;
1522 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1523 	struct ocfs2_dinode *di = NULL;
1524 
1525 	trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1526 					     len, (unsigned long long)pos,
1527 					     oi->ip_dyn_features);
1528 
1529 	/*
1530 	 * Handle inodes which already have inline data 1st.
1531 	 */
1532 	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1533 		if (mmap_folio == NULL &&
1534 		    ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1535 			goto do_inline_write;
1536 
1537 		/*
1538 		 * The write won't fit - we have to give this inode an
1539 		 * inline extent list now.
1540 		 */
1541 		ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1542 		if (ret)
1543 			mlog_errno(ret);
1544 		goto out;
1545 	}
1546 
1547 	/*
1548 	 * Check whether the inode can accept inline data.
1549 	 */
1550 	if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1551 		return 0;
1552 
1553 	/*
1554 	 * Check whether the write can fit.
1555 	 */
1556 	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1557 	if (mmap_folio ||
1558 	    end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1559 		return 0;
1560 
1561 do_inline_write:
1562 	ret = ocfs2_write_begin_inline(mapping, inode, wc);
1563 	if (ret) {
1564 		mlog_errno(ret);
1565 		goto out;
1566 	}
1567 
1568 	/*
1569 	 * This signals to the caller that the data can be written
1570 	 * inline.
1571 	 */
1572 	written = 1;
1573 out:
1574 	return written ? written : ret;
1575 }
1576 
1577 /*
1578  * This function only does anything for file systems which can't
1579  * handle sparse files.
1580  *
1581  * What we want to do here is fill in any hole between the current end
1582  * of allocation and the end of our write. That way the rest of the
1583  * write path can treat it as an non-allocating write, which has no
1584  * special case code for sparse/nonsparse files.
1585  */
ocfs2_expand_nonsparse_inode(struct inode * inode,struct buffer_head * di_bh,loff_t pos,unsigned len,struct ocfs2_write_ctxt * wc)1586 static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1587 					struct buffer_head *di_bh,
1588 					loff_t pos, unsigned len,
1589 					struct ocfs2_write_ctxt *wc)
1590 {
1591 	int ret;
1592 	loff_t newsize = pos + len;
1593 
1594 	BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1595 
1596 	if (newsize <= i_size_read(inode))
1597 		return 0;
1598 
1599 	ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1600 	if (ret)
1601 		mlog_errno(ret);
1602 
1603 	/* There is no wc if this is call from direct. */
1604 	if (wc)
1605 		wc->w_first_new_cpos =
1606 			ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1607 
1608 	return ret;
1609 }
1610 
ocfs2_zero_tail(struct inode * inode,struct buffer_head * di_bh,loff_t pos)1611 static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1612 			   loff_t pos)
1613 {
1614 	int ret = 0;
1615 
1616 	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1617 	if (pos > i_size_read(inode))
1618 		ret = ocfs2_zero_extend(inode, di_bh, pos);
1619 
1620 	return ret;
1621 }
1622 
ocfs2_write_begin_nolock(struct address_space * mapping,loff_t pos,unsigned len,ocfs2_write_type_t type,struct folio ** foliop,void ** fsdata,struct buffer_head * di_bh,struct folio * mmap_folio)1623 int ocfs2_write_begin_nolock(struct address_space *mapping,
1624 		loff_t pos, unsigned len, ocfs2_write_type_t type,
1625 		struct folio **foliop, void **fsdata,
1626 		struct buffer_head *di_bh, struct folio *mmap_folio)
1627 {
1628 	int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1629 	unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1630 	struct ocfs2_write_ctxt *wc;
1631 	struct inode *inode = mapping->host;
1632 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1633 	struct ocfs2_dinode *di;
1634 	struct ocfs2_alloc_context *data_ac = NULL;
1635 	struct ocfs2_alloc_context *meta_ac = NULL;
1636 	handle_t *handle;
1637 	struct ocfs2_extent_tree et;
1638 	int try_free = 1, ret1;
1639 
1640 try_again:
1641 	ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, type, di_bh);
1642 	if (ret) {
1643 		mlog_errno(ret);
1644 		return ret;
1645 	}
1646 
1647 	if (ocfs2_supports_inline_data(osb)) {
1648 		ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1649 						     mmap_folio, wc);
1650 		if (ret == 1) {
1651 			ret = 0;
1652 			goto success;
1653 		}
1654 		if (ret < 0) {
1655 			mlog_errno(ret);
1656 			goto out;
1657 		}
1658 	}
1659 
1660 	/* Direct io change i_size late, should not zero tail here. */
1661 	if (type != OCFS2_WRITE_DIRECT) {
1662 		if (ocfs2_sparse_alloc(osb))
1663 			ret = ocfs2_zero_tail(inode, di_bh, pos);
1664 		else
1665 			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
1666 							   len, wc);
1667 		if (ret) {
1668 			mlog_errno(ret);
1669 			goto out;
1670 		}
1671 	}
1672 
1673 	ret = ocfs2_check_range_for_refcount(inode, pos, len);
1674 	if (ret < 0) {
1675 		mlog_errno(ret);
1676 		goto out;
1677 	} else if (ret == 1) {
1678 		clusters_need = wc->w_clen;
1679 		ret = ocfs2_refcount_cow(inode, di_bh,
1680 					 wc->w_cpos, wc->w_clen, UINT_MAX);
1681 		if (ret) {
1682 			mlog_errno(ret);
1683 			goto out;
1684 		}
1685 	}
1686 
1687 	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1688 					&extents_to_split);
1689 	if (ret) {
1690 		mlog_errno(ret);
1691 		goto out;
1692 	}
1693 	clusters_need += clusters_to_alloc;
1694 
1695 	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1696 
1697 	trace_ocfs2_write_begin_nolock(
1698 			(unsigned long long)OCFS2_I(inode)->ip_blkno,
1699 			(long long)i_size_read(inode),
1700 			le32_to_cpu(di->i_clusters),
1701 			pos, len, type, mmap_folio,
1702 			clusters_to_alloc, extents_to_split);
1703 
1704 	/*
1705 	 * We set w_target_from, w_target_to here so that
1706 	 * ocfs2_write_end() knows which range in the target page to
1707 	 * write out. An allocation requires that we write the entire
1708 	 * cluster range.
1709 	 */
1710 	if (clusters_to_alloc || extents_to_split) {
1711 		/*
1712 		 * XXX: We are stretching the limits of
1713 		 * ocfs2_lock_allocators(). It greatly over-estimates
1714 		 * the work to be done.
1715 		 */
1716 		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1717 					      wc->w_di_bh);
1718 		ret = ocfs2_lock_allocators(inode, &et,
1719 					    clusters_to_alloc, extents_to_split,
1720 					    &data_ac, &meta_ac);
1721 		if (ret) {
1722 			mlog_errno(ret);
1723 			goto out;
1724 		}
1725 
1726 		if (data_ac)
1727 			data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1728 
1729 		credits = ocfs2_calc_extend_credits(inode->i_sb,
1730 						    &di->id2.i_list);
1731 	} else if (type == OCFS2_WRITE_DIRECT)
1732 		/* direct write needs not to start trans if no extents alloc. */
1733 		goto success;
1734 
1735 	/*
1736 	 * We have to zero sparse allocated clusters, unwritten extent clusters,
1737 	 * and non-sparse clusters we just extended.  For non-sparse writes,
1738 	 * we know zeros will only be needed in the first and/or last cluster.
1739 	 */
1740 	if (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1741 			   wc->w_desc[wc->w_clen - 1].c_needs_zero))
1742 		cluster_of_pages = 1;
1743 	else
1744 		cluster_of_pages = 0;
1745 
1746 	ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1747 
1748 	handle = ocfs2_start_trans(osb, credits);
1749 	if (IS_ERR(handle)) {
1750 		ret = PTR_ERR(handle);
1751 		mlog_errno(ret);
1752 		goto out;
1753 	}
1754 
1755 	wc->w_handle = handle;
1756 
1757 	if (clusters_to_alloc) {
1758 		ret = dquot_alloc_space_nodirty(inode,
1759 			ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1760 		if (ret)
1761 			goto out_commit;
1762 	}
1763 
1764 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1765 				      OCFS2_JOURNAL_ACCESS_WRITE);
1766 	if (ret) {
1767 		mlog_errno(ret);
1768 		goto out_quota;
1769 	}
1770 
1771 	/*
1772 	 * Fill our folio array first. That way we've grabbed enough so
1773 	 * that we can zero and flush if we error after adding the
1774 	 * extent.
1775 	 */
1776 	ret = ocfs2_grab_folios_for_write(mapping, wc, wc->w_cpos, pos, len,
1777 			cluster_of_pages, mmap_folio);
1778 	if (ret) {
1779 		/*
1780 		 * ocfs2_grab_folios_for_write() returns -EAGAIN if it
1781 		 * could not lock the target folio. In this case, we exit
1782 		 * with no error and no target folio. This will trigger
1783 		 * the caller, page_mkwrite(), to re-try the operation.
1784 		 */
1785 		if (type == OCFS2_WRITE_MMAP && ret == -EAGAIN) {
1786 			BUG_ON(wc->w_target_folio);
1787 			ret = 0;
1788 			goto out_quota;
1789 		}
1790 
1791 		mlog_errno(ret);
1792 		goto out_quota;
1793 	}
1794 
1795 	ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1796 					  len);
1797 	if (ret) {
1798 		mlog_errno(ret);
1799 		goto out_quota;
1800 	}
1801 
1802 	if (data_ac)
1803 		ocfs2_free_alloc_context(data_ac);
1804 	if (meta_ac)
1805 		ocfs2_free_alloc_context(meta_ac);
1806 
1807 success:
1808 	if (foliop)
1809 		*foliop = wc->w_target_folio;
1810 	*fsdata = wc;
1811 	return 0;
1812 out_quota:
1813 	if (clusters_to_alloc)
1814 		dquot_free_space(inode,
1815 			  ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1816 out_commit:
1817 	ocfs2_commit_trans(osb, handle);
1818 
1819 out:
1820 	/*
1821 	 * The mmapped page won't be unlocked in ocfs2_free_write_ctxt(),
1822 	 * even in case of error here like ENOSPC and ENOMEM. So, we need
1823 	 * to unlock the target page manually to prevent deadlocks when
1824 	 * retrying again on ENOSPC, or when returning non-VM_FAULT_LOCKED
1825 	 * to VM code.
1826 	 */
1827 	if (wc->w_target_locked)
1828 		folio_unlock(mmap_folio);
1829 
1830 	ocfs2_free_write_ctxt(inode, wc);
1831 
1832 	if (data_ac) {
1833 		ocfs2_free_alloc_context(data_ac);
1834 		data_ac = NULL;
1835 	}
1836 	if (meta_ac) {
1837 		ocfs2_free_alloc_context(meta_ac);
1838 		meta_ac = NULL;
1839 	}
1840 
1841 	if (ret == -ENOSPC && try_free) {
1842 		/*
1843 		 * Try to free some truncate log so that we can have enough
1844 		 * clusters to allocate.
1845 		 */
1846 		try_free = 0;
1847 
1848 		ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1849 		if (ret1 == 1)
1850 			goto try_again;
1851 
1852 		if (ret1 < 0)
1853 			mlog_errno(ret1);
1854 	}
1855 
1856 	return ret;
1857 }
1858 
ocfs2_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,struct folio ** foliop,void ** fsdata)1859 static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1860 			     loff_t pos, unsigned len,
1861 			     struct folio **foliop, void **fsdata)
1862 {
1863 	int ret;
1864 	struct buffer_head *di_bh = NULL;
1865 	struct inode *inode = mapping->host;
1866 
1867 	ret = ocfs2_inode_lock(inode, &di_bh, 1);
1868 	if (ret) {
1869 		mlog_errno(ret);
1870 		return ret;
1871 	}
1872 
1873 	/*
1874 	 * Take alloc sem here to prevent concurrent lookups. That way
1875 	 * the mapping, zeroing and tree manipulation within
1876 	 * ocfs2_write() will be safe against ->read_folio(). This
1877 	 * should also serve to lock out allocation from a shared
1878 	 * writeable region.
1879 	 */
1880 	down_write(&OCFS2_I(inode)->ip_alloc_sem);
1881 
1882 	ret = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_BUFFER,
1883 				       foliop, fsdata, di_bh, NULL);
1884 	if (ret) {
1885 		mlog_errno(ret);
1886 		goto out_fail;
1887 	}
1888 
1889 	brelse(di_bh);
1890 
1891 	return 0;
1892 
1893 out_fail:
1894 	up_write(&OCFS2_I(inode)->ip_alloc_sem);
1895 
1896 	brelse(di_bh);
1897 	ocfs2_inode_unlock(inode, 1);
1898 
1899 	return ret;
1900 }
1901 
ocfs2_write_end_inline(struct inode * inode,loff_t pos,unsigned len,unsigned * copied,struct ocfs2_dinode * di,struct ocfs2_write_ctxt * wc)1902 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1903 				   unsigned len, unsigned *copied,
1904 				   struct ocfs2_dinode *di,
1905 				   struct ocfs2_write_ctxt *wc)
1906 {
1907 	if (unlikely(*copied < len)) {
1908 		if (!folio_test_uptodate(wc->w_target_folio)) {
1909 			*copied = 0;
1910 			return;
1911 		}
1912 	}
1913 
1914 	memcpy_from_folio(di->id2.i_data.id_data + pos, wc->w_target_folio,
1915 			pos, *copied);
1916 
1917 	trace_ocfs2_write_end_inline(
1918 	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1919 	     (unsigned long long)pos, *copied,
1920 	     le16_to_cpu(di->id2.i_data.id_count),
1921 	     le16_to_cpu(di->i_dyn_features));
1922 }
1923 
ocfs2_write_end_nolock(struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,void * fsdata)1924 int ocfs2_write_end_nolock(struct address_space *mapping, loff_t pos,
1925 		unsigned len, unsigned copied, void *fsdata)
1926 {
1927 	int i, ret;
1928 	size_t from, to, start = pos & (PAGE_SIZE - 1);
1929 	struct inode *inode = mapping->host;
1930 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1931 	struct ocfs2_write_ctxt *wc = fsdata;
1932 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1933 	handle_t *handle = wc->w_handle;
1934 
1935 	BUG_ON(!list_empty(&wc->w_unwritten_list));
1936 
1937 	if (handle) {
1938 		ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode),
1939 				wc->w_di_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1940 		if (ret) {
1941 			copied = ret;
1942 			mlog_errno(ret);
1943 			goto out;
1944 		}
1945 	}
1946 
1947 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1948 		ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1949 		goto out_write_size;
1950 	}
1951 
1952 	if (unlikely(copied < len) && wc->w_target_folio) {
1953 		loff_t new_isize;
1954 
1955 		if (!folio_test_uptodate(wc->w_target_folio))
1956 			copied = 0;
1957 
1958 		new_isize = max_t(loff_t, i_size_read(inode), pos + copied);
1959 		if (new_isize > folio_pos(wc->w_target_folio))
1960 			ocfs2_zero_new_buffers(wc->w_target_folio, start+copied,
1961 					       start+len);
1962 		else {
1963 			/*
1964 			 * When folio is fully beyond new isize (data copy
1965 			 * failed), do not bother zeroing the folio. Invalidate
1966 			 * it instead so that writeback does not get confused
1967 			 * put page & buffer dirty bits into inconsistent
1968 			 * state.
1969 			 */
1970 			block_invalidate_folio(wc->w_target_folio, 0,
1971 					folio_size(wc->w_target_folio));
1972 		}
1973 	}
1974 	if (wc->w_target_folio)
1975 		flush_dcache_folio(wc->w_target_folio);
1976 
1977 	for (i = 0; i < wc->w_num_folios; i++) {
1978 		struct folio *folio = wc->w_folios[i];
1979 
1980 		/* This is the direct io target folio */
1981 		if (folio == NULL)
1982 			continue;
1983 
1984 		if (folio == wc->w_target_folio) {
1985 			from = wc->w_target_from;
1986 			to = wc->w_target_to;
1987 
1988 			BUG_ON(from > folio_size(folio) ||
1989 			       to > folio_size(folio) ||
1990 			       to < from);
1991 		} else {
1992 			/*
1993 			 * Pages adjacent to the target (if any) imply
1994 			 * a hole-filling write in which case we want
1995 			 * to flush their entire range.
1996 			 */
1997 			from = 0;
1998 			to = folio_size(folio);
1999 		}
2000 
2001 		if (folio_buffers(folio)) {
2002 			if (handle && ocfs2_should_order_data(inode)) {
2003 				loff_t start_byte = folio_pos(folio) + from;
2004 				loff_t length = to - from;
2005 				ocfs2_jbd2_inode_add_write(handle, inode,
2006 							   start_byte, length);
2007 			}
2008 			block_commit_write(folio, from, to);
2009 		}
2010 	}
2011 
2012 out_write_size:
2013 	/* Direct io do not update i_size here. */
2014 	if (wc->w_type != OCFS2_WRITE_DIRECT) {
2015 		pos += copied;
2016 		if (pos > i_size_read(inode)) {
2017 			i_size_write(inode, pos);
2018 			mark_inode_dirty(inode);
2019 		}
2020 		inode->i_blocks = ocfs2_inode_sector_count(inode);
2021 		di->i_size = cpu_to_le64((u64)i_size_read(inode));
2022 		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
2023 		di->i_mtime = di->i_ctime = cpu_to_le64(inode_get_mtime_sec(inode));
2024 		di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode_get_mtime_nsec(inode));
2025 		if (handle)
2026 			ocfs2_update_inode_fsync_trans(handle, inode, 1);
2027 	}
2028 	if (handle)
2029 		ocfs2_journal_dirty(handle, wc->w_di_bh);
2030 
2031 out:
2032 	/* unlock pages before dealloc since it needs acquiring j_trans_barrier
2033 	 * lock, or it will cause a deadlock since journal commit threads holds
2034 	 * this lock and will ask for the page lock when flushing the data.
2035 	 * put it here to preserve the unlock order.
2036 	 */
2037 	ocfs2_unlock_folios(wc);
2038 
2039 	if (handle)
2040 		ocfs2_commit_trans(osb, handle);
2041 
2042 	ocfs2_run_deallocs(osb, &wc->w_dealloc);
2043 
2044 	brelse(wc->w_di_bh);
2045 	kfree(wc);
2046 
2047 	return copied;
2048 }
2049 
ocfs2_write_end(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct folio * folio,void * fsdata)2050 static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2051 			   loff_t pos, unsigned len, unsigned copied,
2052 			   struct folio *folio, void *fsdata)
2053 {
2054 	int ret;
2055 	struct inode *inode = mapping->host;
2056 
2057 	ret = ocfs2_write_end_nolock(mapping, pos, len, copied, fsdata);
2058 
2059 	up_write(&OCFS2_I(inode)->ip_alloc_sem);
2060 	ocfs2_inode_unlock(inode, 1);
2061 
2062 	return ret;
2063 }
2064 
2065 struct ocfs2_dio_write_ctxt {
2066 	struct list_head	dw_zero_list;
2067 	unsigned		dw_zero_count;
2068 	int			dw_orphaned;
2069 	pid_t			dw_writer_pid;
2070 };
2071 
2072 static struct ocfs2_dio_write_ctxt *
ocfs2_dio_alloc_write_ctx(struct buffer_head * bh,int * alloc)2073 ocfs2_dio_alloc_write_ctx(struct buffer_head *bh, int *alloc)
2074 {
2075 	struct ocfs2_dio_write_ctxt *dwc = NULL;
2076 
2077 	if (bh->b_private)
2078 		return bh->b_private;
2079 
2080 	dwc = kmalloc(sizeof(struct ocfs2_dio_write_ctxt), GFP_NOFS);
2081 	if (dwc == NULL)
2082 		return NULL;
2083 	INIT_LIST_HEAD(&dwc->dw_zero_list);
2084 	dwc->dw_zero_count = 0;
2085 	dwc->dw_orphaned = 0;
2086 	dwc->dw_writer_pid = task_pid_nr(current);
2087 	bh->b_private = dwc;
2088 	*alloc = 1;
2089 
2090 	return dwc;
2091 }
2092 
ocfs2_dio_free_write_ctx(struct inode * inode,struct ocfs2_dio_write_ctxt * dwc)2093 static void ocfs2_dio_free_write_ctx(struct inode *inode,
2094 				     struct ocfs2_dio_write_ctxt *dwc)
2095 {
2096 	ocfs2_free_unwritten_list(inode, &dwc->dw_zero_list);
2097 	kfree(dwc);
2098 }
2099 
2100 /*
2101  * TODO: Make this into a generic get_blocks function.
2102  *
2103  * From do_direct_io in direct-io.c:
2104  *  "So what we do is to permit the ->get_blocks function to populate
2105  *   bh.b_size with the size of IO which is permitted at this offset and
2106  *   this i_blkbits."
2107  *
2108  * This function is called directly from get_more_blocks in direct-io.c.
2109  *
2110  * called like this: dio->get_blocks(dio->inode, fs_startblk,
2111  * 					fs_count, map_bh, dio->rw == WRITE);
2112  */
ocfs2_dio_wr_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)2113 static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock,
2114 			       struct buffer_head *bh_result, int create)
2115 {
2116 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2117 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2118 	struct ocfs2_write_ctxt *wc;
2119 	struct ocfs2_write_cluster_desc *desc = NULL;
2120 	struct ocfs2_dio_write_ctxt *dwc = NULL;
2121 	struct buffer_head *di_bh = NULL;
2122 	u64 p_blkno;
2123 	unsigned int i_blkbits = inode->i_sb->s_blocksize_bits;
2124 	loff_t pos = iblock << i_blkbits;
2125 	sector_t endblk = (i_size_read(inode) - 1) >> i_blkbits;
2126 	unsigned len, total_len = bh_result->b_size;
2127 	int ret = 0, first_get_block = 0;
2128 
2129 	len = osb->s_clustersize - (pos & (osb->s_clustersize - 1));
2130 	len = min(total_len, len);
2131 
2132 	/*
2133 	 * bh_result->b_size is count in get_more_blocks according to write
2134 	 * "pos" and "end", we need map twice to return different buffer state:
2135 	 * 1. area in file size, not set NEW;
2136 	 * 2. area out file size, set  NEW.
2137 	 *
2138 	 *		   iblock    endblk
2139 	 * |--------|---------|---------|---------
2140 	 * |<-------area in file------->|
2141 	 */
2142 
2143 	if ((iblock <= endblk) &&
2144 	    ((iblock + ((len - 1) >> i_blkbits)) > endblk))
2145 		len = (endblk - iblock + 1) << i_blkbits;
2146 
2147 	mlog(0, "get block of %lu at %llu:%u req %u\n",
2148 			inode->i_ino, pos, len, total_len);
2149 
2150 	/*
2151 	 * Because we need to change file size in ocfs2_dio_end_io_write(), or
2152 	 * we may need to add it to orphan dir. So can not fall to fast path
2153 	 * while file size will be changed.
2154 	 */
2155 	if (pos + total_len <= i_size_read(inode)) {
2156 
2157 		/* This is the fast path for re-write. */
2158 		ret = ocfs2_lock_get_block(inode, iblock, bh_result, create);
2159 		if (buffer_mapped(bh_result) &&
2160 		    !buffer_new(bh_result) &&
2161 		    ret == 0)
2162 			goto out;
2163 
2164 		/* Clear state set by ocfs2_get_block. */
2165 		bh_result->b_state = 0;
2166 	}
2167 
2168 	dwc = ocfs2_dio_alloc_write_ctx(bh_result, &first_get_block);
2169 	if (unlikely(dwc == NULL)) {
2170 		ret = -ENOMEM;
2171 		mlog_errno(ret);
2172 		goto out;
2173 	}
2174 
2175 	if (ocfs2_clusters_for_bytes(inode->i_sb, pos + total_len) >
2176 	    ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode)) &&
2177 	    !dwc->dw_orphaned) {
2178 		/*
2179 		 * when we are going to alloc extents beyond file size, add the
2180 		 * inode to orphan dir, so we can recall those spaces when
2181 		 * system crashed during write.
2182 		 */
2183 		ret = ocfs2_add_inode_to_orphan(osb, inode);
2184 		if (ret < 0) {
2185 			mlog_errno(ret);
2186 			goto out;
2187 		}
2188 		dwc->dw_orphaned = 1;
2189 	}
2190 
2191 	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2192 	if (ret) {
2193 		mlog_errno(ret);
2194 		goto out;
2195 	}
2196 
2197 	down_write(&oi->ip_alloc_sem);
2198 
2199 	if (first_get_block) {
2200 		if (ocfs2_sparse_alloc(osb))
2201 			ret = ocfs2_zero_tail(inode, di_bh, pos);
2202 		else
2203 			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
2204 							   total_len, NULL);
2205 		if (ret < 0) {
2206 			mlog_errno(ret);
2207 			goto unlock;
2208 		}
2209 	}
2210 
2211 	ret = ocfs2_write_begin_nolock(inode->i_mapping, pos, len,
2212 				       OCFS2_WRITE_DIRECT, NULL,
2213 				       (void **)&wc, di_bh, NULL);
2214 	if (ret) {
2215 		mlog_errno(ret);
2216 		goto unlock;
2217 	}
2218 
2219 	desc = &wc->w_desc[0];
2220 
2221 	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, desc->c_phys);
2222 	BUG_ON(p_blkno == 0);
2223 	p_blkno += iblock & (u64)(ocfs2_clusters_to_blocks(inode->i_sb, 1) - 1);
2224 
2225 	map_bh(bh_result, inode->i_sb, p_blkno);
2226 	bh_result->b_size = len;
2227 	if (desc->c_needs_zero)
2228 		set_buffer_new(bh_result);
2229 
2230 	if (iblock > endblk)
2231 		set_buffer_new(bh_result);
2232 
2233 	/* May sleep in end_io. It should not happen in a irq context. So defer
2234 	 * it to dio work queue. */
2235 	set_buffer_defer_completion(bh_result);
2236 
2237 	if (!list_empty(&wc->w_unwritten_list)) {
2238 		struct ocfs2_unwritten_extent *ue = NULL;
2239 
2240 		ue = list_first_entry(&wc->w_unwritten_list,
2241 				      struct ocfs2_unwritten_extent,
2242 				      ue_node);
2243 		BUG_ON(ue->ue_cpos != desc->c_cpos);
2244 		/* The physical address may be 0, fill it. */
2245 		ue->ue_phys = desc->c_phys;
2246 
2247 		list_splice_tail_init(&wc->w_unwritten_list, &dwc->dw_zero_list);
2248 		dwc->dw_zero_count += wc->w_unwritten_count;
2249 	}
2250 
2251 	ret = ocfs2_write_end_nolock(inode->i_mapping, pos, len, len, wc);
2252 	BUG_ON(ret != len);
2253 	ret = 0;
2254 unlock:
2255 	up_write(&oi->ip_alloc_sem);
2256 	ocfs2_inode_unlock(inode, 1);
2257 	brelse(di_bh);
2258 out:
2259 	return ret;
2260 }
2261 
ocfs2_dio_end_io_write(struct inode * inode,struct ocfs2_dio_write_ctxt * dwc,loff_t offset,ssize_t bytes)2262 static int ocfs2_dio_end_io_write(struct inode *inode,
2263 				  struct ocfs2_dio_write_ctxt *dwc,
2264 				  loff_t offset,
2265 				  ssize_t bytes)
2266 {
2267 	struct ocfs2_cached_dealloc_ctxt dealloc;
2268 	struct ocfs2_extent_tree et;
2269 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2270 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2271 	struct ocfs2_unwritten_extent *ue = NULL;
2272 	struct buffer_head *di_bh = NULL;
2273 	struct ocfs2_dinode *di;
2274 	struct ocfs2_alloc_context *data_ac = NULL;
2275 	struct ocfs2_alloc_context *meta_ac = NULL;
2276 	handle_t *handle = NULL;
2277 	loff_t end = offset + bytes;
2278 	int ret = 0, credits = 0;
2279 
2280 	ocfs2_init_dealloc_ctxt(&dealloc);
2281 
2282 	/* We do clear unwritten, delete orphan, change i_size here. If neither
2283 	 * of these happen, we can skip all this. */
2284 	if (list_empty(&dwc->dw_zero_list) &&
2285 	    end <= i_size_read(inode) &&
2286 	    !dwc->dw_orphaned)
2287 		goto out;
2288 
2289 	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2290 	if (ret < 0) {
2291 		mlog_errno(ret);
2292 		goto out;
2293 	}
2294 
2295 	down_write(&oi->ip_alloc_sem);
2296 
2297 	/* Delete orphan before acquire i_rwsem. */
2298 	if (dwc->dw_orphaned) {
2299 		BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
2300 
2301 		end = end > i_size_read(inode) ? end : 0;
2302 
2303 		ret = ocfs2_del_inode_from_orphan(osb, inode, di_bh,
2304 				!!end, end);
2305 		if (ret < 0)
2306 			mlog_errno(ret);
2307 	}
2308 
2309 	di = (struct ocfs2_dinode *)di_bh->b_data;
2310 
2311 	ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
2312 
2313 	/* Attach dealloc with extent tree in case that we may reuse extents
2314 	 * which are already unlinked from current extent tree due to extent
2315 	 * rotation and merging.
2316 	 */
2317 	et.et_dealloc = &dealloc;
2318 
2319 	ret = ocfs2_lock_allocators(inode, &et, 0, dwc->dw_zero_count*2,
2320 				    &data_ac, &meta_ac);
2321 	if (ret) {
2322 		mlog_errno(ret);
2323 		goto unlock;
2324 	}
2325 
2326 	credits = ocfs2_calc_extend_credits(inode->i_sb, &di->id2.i_list);
2327 
2328 	handle = ocfs2_start_trans(osb, credits);
2329 	if (IS_ERR(handle)) {
2330 		ret = PTR_ERR(handle);
2331 		mlog_errno(ret);
2332 		goto unlock;
2333 	}
2334 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
2335 				      OCFS2_JOURNAL_ACCESS_WRITE);
2336 	if (ret) {
2337 		mlog_errno(ret);
2338 		goto commit;
2339 	}
2340 
2341 	list_for_each_entry(ue, &dwc->dw_zero_list, ue_node) {
2342 		ret = ocfs2_assure_trans_credits(handle, credits);
2343 		if (ret < 0) {
2344 			mlog_errno(ret);
2345 			break;
2346 		}
2347 		ret = ocfs2_mark_extent_written(inode, &et, handle,
2348 						ue->ue_cpos, 1,
2349 						ue->ue_phys,
2350 						meta_ac, &dealloc);
2351 		if (ret < 0) {
2352 			mlog_errno(ret);
2353 			break;
2354 		}
2355 	}
2356 
2357 	if (end > i_size_read(inode)) {
2358 		ret = ocfs2_set_inode_size(handle, inode, di_bh, end);
2359 		if (ret < 0)
2360 			mlog_errno(ret);
2361 	}
2362 commit:
2363 	ocfs2_commit_trans(osb, handle);
2364 unlock:
2365 	up_write(&oi->ip_alloc_sem);
2366 	ocfs2_inode_unlock(inode, 1);
2367 	brelse(di_bh);
2368 out:
2369 	if (data_ac)
2370 		ocfs2_free_alloc_context(data_ac);
2371 	if (meta_ac)
2372 		ocfs2_free_alloc_context(meta_ac);
2373 	ocfs2_run_deallocs(osb, &dealloc);
2374 	ocfs2_dio_free_write_ctx(inode, dwc);
2375 
2376 	return ret;
2377 }
2378 
2379 /*
2380  * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
2381  * particularly interested in the aio/dio case.  We use the rw_lock DLM lock
2382  * to protect io on one node from truncation on another.
2383  */
ocfs2_dio_end_io(struct kiocb * iocb,loff_t offset,ssize_t bytes,void * private)2384 static int ocfs2_dio_end_io(struct kiocb *iocb,
2385 			    loff_t offset,
2386 			    ssize_t bytes,
2387 			    void *private)
2388 {
2389 	struct inode *inode = file_inode(iocb->ki_filp);
2390 	int level;
2391 	int ret = 0;
2392 
2393 	/* this io's submitter should not have unlocked this before we could */
2394 	BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
2395 
2396 	if (bytes <= 0)
2397 		mlog_ratelimited(ML_ERROR, "Direct IO failed, bytes = %lld",
2398 				 (long long)bytes);
2399 	if (private) {
2400 		if (bytes > 0)
2401 			ret = ocfs2_dio_end_io_write(inode, private, offset,
2402 						     bytes);
2403 		else
2404 			ocfs2_dio_free_write_ctx(inode, private);
2405 	}
2406 
2407 	ocfs2_iocb_clear_rw_locked(iocb);
2408 
2409 	level = ocfs2_iocb_rw_locked_level(iocb);
2410 	ocfs2_rw_unlock(inode, level);
2411 	return ret;
2412 }
2413 
ocfs2_direct_IO(struct kiocb * iocb,struct iov_iter * iter)2414 static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
2415 {
2416 	struct file *file = iocb->ki_filp;
2417 	struct inode *inode = file->f_mapping->host;
2418 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2419 	get_block_t *get_block;
2420 
2421 	/*
2422 	 * Fallback to buffered I/O if we see an inode without
2423 	 * extents.
2424 	 */
2425 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
2426 		return 0;
2427 
2428 	/* Fallback to buffered I/O if we do not support append dio. */
2429 	if (iocb->ki_pos + iter->count > i_size_read(inode) &&
2430 	    !ocfs2_supports_append_dio(osb))
2431 		return 0;
2432 
2433 	if (iov_iter_rw(iter) == READ)
2434 		get_block = ocfs2_lock_get_block;
2435 	else
2436 		get_block = ocfs2_dio_wr_get_block;
2437 
2438 	return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
2439 				    iter, get_block,
2440 				    ocfs2_dio_end_io, 0);
2441 }
2442 
2443 const struct address_space_operations ocfs2_aops = {
2444 	.dirty_folio		= block_dirty_folio,
2445 	.read_folio		= ocfs2_read_folio,
2446 	.readahead		= ocfs2_readahead,
2447 	.writepages		= ocfs2_writepages,
2448 	.write_begin		= ocfs2_write_begin,
2449 	.write_end		= ocfs2_write_end,
2450 	.bmap			= ocfs2_bmap,
2451 	.direct_IO		= ocfs2_direct_IO,
2452 	.invalidate_folio	= block_invalidate_folio,
2453 	.release_folio		= ocfs2_release_folio,
2454 	.migrate_folio		= buffer_migrate_folio,
2455 	.is_partially_uptodate	= block_is_partially_uptodate,
2456 	.error_remove_folio	= generic_error_remove_folio,
2457 };
2458