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 	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 
115 bail:
116 	brelse(bh);
117 
118 	return err;
119 }
120 
ocfs2_lock_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)121 static 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 
ocfs2_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)134 int ocfs2_get_block(struct inode *inode, sector_t iblock,
135 		    struct buffer_head *bh_result, int create)
136 {
137 	int err = 0;
138 	unsigned int ext_flags;
139 	u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
140 	u64 p_blkno, count, past_eof;
141 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
142 
143 	trace_ocfs2_get_block((unsigned long long)OCFS2_I(inode)->ip_blkno,
144 			      (unsigned long long)iblock, bh_result, create);
145 
146 	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
147 		mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
148 		     inode, inode->i_ino);
149 
150 	if (S_ISLNK(inode->i_mode)) {
151 		/* this always does I/O for some reason. */
152 		err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
153 		goto bail;
154 	}
155 
156 	err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
157 					  &ext_flags);
158 	if (err) {
159 		mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
160 		     "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
161 		     (unsigned long long)p_blkno);
162 		goto bail;
163 	}
164 
165 	if (max_blocks < count)
166 		count = max_blocks;
167 
168 	/*
169 	 * ocfs2 never allocates in this function - the only time we
170 	 * need to use BH_New is when we're extending i_size on a file
171 	 * system which doesn't support holes, in which case BH_New
172 	 * allows __block_write_begin() to zero.
173 	 *
174 	 * If we see this on a sparse file system, then a truncate has
175 	 * raced us and removed the cluster. In this case, we clear
176 	 * the buffers dirty and uptodate bits and let the buffer code
177 	 * ignore it as a hole.
178 	 */
179 	if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
180 		clear_buffer_dirty(bh_result);
181 		clear_buffer_uptodate(bh_result);
182 		goto bail;
183 	}
184 
185 	/* Treat the unwritten extent as a hole for zeroing purposes. */
186 	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
187 		map_bh(bh_result, inode->i_sb, p_blkno);
188 
189 	bh_result->b_size = count << inode->i_blkbits;
190 
191 	if (!ocfs2_sparse_alloc(osb)) {
192 		if (p_blkno == 0) {
193 			err = -EIO;
194 			mlog(ML_ERROR,
195 			     "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
196 			     (unsigned long long)iblock,
197 			     (unsigned long long)p_blkno,
198 			     (unsigned long long)OCFS2_I(inode)->ip_blkno);
199 			mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
200 			dump_stack();
201 			goto bail;
202 		}
203 	}
204 
205 	past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
206 
207 	trace_ocfs2_get_block_end((unsigned long long)OCFS2_I(inode)->ip_blkno,
208 				  (unsigned long long)past_eof);
209 	if (create && (iblock >= past_eof))
210 		set_buffer_new(bh_result);
211 
212 bail:
213 	if (err < 0)
214 		err = -EIO;
215 
216 	return err;
217 }
218 
ocfs2_read_inline_data(struct inode * inode,struct page * page,struct buffer_head * di_bh)219 int ocfs2_read_inline_data(struct inode *inode, struct page *page,
220 			   struct buffer_head *di_bh)
221 {
222 	void *kaddr;
223 	loff_t size;
224 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
225 
226 	if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
227 		ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag\n",
228 			    (unsigned long long)OCFS2_I(inode)->ip_blkno);
229 		return -EROFS;
230 	}
231 
232 	size = i_size_read(inode);
233 
234 	if (size > PAGE_SIZE ||
235 	    size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
236 		ocfs2_error(inode->i_sb,
237 			    "Inode %llu has with inline data has bad size: %Lu\n",
238 			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
239 			    (unsigned long long)size);
240 		return -EROFS;
241 	}
242 
243 	kaddr = kmap_atomic(page);
244 	if (size)
245 		memcpy(kaddr, di->id2.i_data.id_data, size);
246 	/* Clear the remaining part of the page */
247 	memset(kaddr + size, 0, PAGE_SIZE - size);
248 	flush_dcache_page(page);
249 	kunmap_atomic(kaddr);
250 
251 	SetPageUptodate(page);
252 
253 	return 0;
254 }
255 
ocfs2_readpage_inline(struct inode * inode,struct page * page)256 static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
257 {
258 	int ret;
259 	struct buffer_head *di_bh = NULL;
260 
261 	BUG_ON(!PageLocked(page));
262 	BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
263 
264 	ret = ocfs2_read_inode_block(inode, &di_bh);
265 	if (ret) {
266 		mlog_errno(ret);
267 		goto out;
268 	}
269 
270 	ret = ocfs2_read_inline_data(inode, page, di_bh);
271 out:
272 	unlock_page(page);
273 
274 	brelse(di_bh);
275 	return ret;
276 }
277 
ocfs2_read_folio(struct file * file,struct folio * folio)278 static int ocfs2_read_folio(struct file *file, struct folio *folio)
279 {
280 	struct inode *inode = folio->mapping->host;
281 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
282 	loff_t start = folio_pos(folio);
283 	int ret, unlock = 1;
284 
285 	trace_ocfs2_readpage((unsigned long long)oi->ip_blkno, folio->index);
286 
287 	ret = ocfs2_inode_lock_with_page(inode, NULL, 0, &folio->page);
288 	if (ret != 0) {
289 		if (ret == AOP_TRUNCATED_PAGE)
290 			unlock = 0;
291 		mlog_errno(ret);
292 		goto out;
293 	}
294 
295 	if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
296 		/*
297 		 * Unlock the folio and cycle ip_alloc_sem so that we don't
298 		 * busyloop waiting for ip_alloc_sem to unlock
299 		 */
300 		ret = AOP_TRUNCATED_PAGE;
301 		folio_unlock(folio);
302 		unlock = 0;
303 		down_read(&oi->ip_alloc_sem);
304 		up_read(&oi->ip_alloc_sem);
305 		goto out_inode_unlock;
306 	}
307 
308 	/*
309 	 * i_size might have just been updated as we grabed the meta lock.  We
310 	 * might now be discovering a truncate that hit on another node.
311 	 * block_read_full_folio->get_block freaks out if it is asked to read
312 	 * beyond the end of a file, so we check here.  Callers
313 	 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
314 	 * and notice that the folio they just read isn't needed.
315 	 *
316 	 * XXX sys_readahead() seems to get that wrong?
317 	 */
318 	if (start >= i_size_read(inode)) {
319 		folio_zero_segment(folio, 0, folio_size(folio));
320 		folio_mark_uptodate(folio);
321 		ret = 0;
322 		goto out_alloc;
323 	}
324 
325 	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
326 		ret = ocfs2_readpage_inline(inode, &folio->page);
327 	else
328 		ret = block_read_full_folio(folio, ocfs2_get_block);
329 	unlock = 0;
330 
331 out_alloc:
332 	up_read(&oi->ip_alloc_sem);
333 out_inode_unlock:
334 	ocfs2_inode_unlock(inode, 0);
335 out:
336 	if (unlock)
337 		folio_unlock(folio);
338 	return ret;
339 }
340 
341 /*
342  * This is used only for read-ahead. Failures or difficult to handle
343  * situations are safe to ignore.
344  *
345  * Right now, we don't bother with BH_Boundary - in-inode extent lists
346  * are quite large (243 extents on 4k blocks), so most inodes don't
347  * grow out to a tree. If need be, detecting boundary extents could
348  * trivially be added in a future version of ocfs2_get_block().
349  */
ocfs2_readahead(struct readahead_control * rac)350 static void ocfs2_readahead(struct readahead_control *rac)
351 {
352 	int ret;
353 	struct inode *inode = rac->mapping->host;
354 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
355 
356 	/*
357 	 * Use the nonblocking flag for the dlm code to avoid page
358 	 * lock inversion, but don't bother with retrying.
359 	 */
360 	ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
361 	if (ret)
362 		return;
363 
364 	if (down_read_trylock(&oi->ip_alloc_sem) == 0)
365 		goto out_unlock;
366 
367 	/*
368 	 * Don't bother with inline-data. There isn't anything
369 	 * to read-ahead in that case anyway...
370 	 */
371 	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
372 		goto out_up;
373 
374 	/*
375 	 * Check whether a remote node truncated this file - we just
376 	 * drop out in that case as it's not worth handling here.
377 	 */
378 	if (readahead_pos(rac) >= i_size_read(inode))
379 		goto out_up;
380 
381 	mpage_readahead(rac, ocfs2_get_block);
382 
383 out_up:
384 	up_read(&oi->ip_alloc_sem);
385 out_unlock:
386 	ocfs2_inode_unlock(inode, 0);
387 }
388 
389 /* Note: Because we don't support holes, our allocation has
390  * already happened (allocation writes zeros to the file data)
391  * so we don't have to worry about ordered writes in
392  * ocfs2_writepage.
393  *
394  * ->writepage is called during the process of invalidating the page cache
395  * during blocked lock processing.  It can't block on any cluster locks
396  * to during block mapping.  It's relying on the fact that the block
397  * mapping can't have disappeared under the dirty pages that it is
398  * being asked to write back.
399  */
ocfs2_writepage(struct page * page,struct writeback_control * wbc)400 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
401 {
402 	trace_ocfs2_writepage(
403 		(unsigned long long)OCFS2_I(page->mapping->host)->ip_blkno,
404 		page->index);
405 
406 	return block_write_full_page(page, ocfs2_get_block, wbc);
407 }
408 
409 /* Taken from ext3. We don't necessarily need the full blown
410  * functionality yet, but IMHO it's better to cut and paste the whole
411  * thing so we can avoid introducing our own bugs (and easily pick up
412  * 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))413 int walk_page_buffers(	handle_t *handle,
414 			struct buffer_head *head,
415 			unsigned from,
416 			unsigned to,
417 			int *partial,
418 			int (*fn)(	handle_t *handle,
419 					struct buffer_head *bh))
420 {
421 	struct buffer_head *bh;
422 	unsigned block_start, block_end;
423 	unsigned blocksize = head->b_size;
424 	int err, ret = 0;
425 	struct buffer_head *next;
426 
427 	for (	bh = head, block_start = 0;
428 		ret == 0 && (bh != head || !block_start);
429 	    	block_start = block_end, bh = next)
430 	{
431 		next = bh->b_this_page;
432 		block_end = block_start + blocksize;
433 		if (block_end <= from || block_start >= to) {
434 			if (partial && !buffer_uptodate(bh))
435 				*partial = 1;
436 			continue;
437 		}
438 		err = (*fn)(handle, bh);
439 		if (!ret)
440 			ret = err;
441 	}
442 	return ret;
443 }
444 
ocfs2_bmap(struct address_space * mapping,sector_t block)445 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
446 {
447 	sector_t status;
448 	u64 p_blkno = 0;
449 	int err = 0;
450 	struct inode *inode = mapping->host;
451 
452 	trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno,
453 			 (unsigned long long)block);
454 
455 	/*
456 	 * The swap code (ab-)uses ->bmap to get a block mapping and then
457 	 * bypasseѕ the file system for actual I/O.  We really can't allow
458 	 * that on refcounted inodes, so we have to skip out here.  And yes,
459 	 * 0 is the magic code for a bmap error..
460 	 */
461 	if (ocfs2_is_refcount_inode(inode))
462 		return 0;
463 
464 	/* We don't need to lock journal system files, since they aren't
465 	 * accessed concurrently from multiple nodes.
466 	 */
467 	if (!INODE_JOURNAL(inode)) {
468 		err = ocfs2_inode_lock(inode, NULL, 0);
469 		if (err) {
470 			if (err != -ENOENT)
471 				mlog_errno(err);
472 			goto bail;
473 		}
474 		down_read(&OCFS2_I(inode)->ip_alloc_sem);
475 	}
476 
477 	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
478 		err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
479 						  NULL);
480 
481 	if (!INODE_JOURNAL(inode)) {
482 		up_read(&OCFS2_I(inode)->ip_alloc_sem);
483 		ocfs2_inode_unlock(inode, 0);
484 	}
485 
486 	if (err) {
487 		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
488 		     (unsigned long long)block);
489 		mlog_errno(err);
490 		goto bail;
491 	}
492 
493 bail:
494 	status = err ? 0 : p_blkno;
495 
496 	return status;
497 }
498 
ocfs2_release_folio(struct folio * folio,gfp_t wait)499 static bool ocfs2_release_folio(struct folio *folio, gfp_t wait)
500 {
501 	if (!folio_buffers(folio))
502 		return false;
503 	return try_to_free_buffers(folio);
504 }
505 
ocfs2_figure_cluster_boundaries(struct ocfs2_super * osb,u32 cpos,unsigned int * start,unsigned int * end)506 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
507 					    u32 cpos,
508 					    unsigned int *start,
509 					    unsigned int *end)
510 {
511 	unsigned int cluster_start = 0, cluster_end = PAGE_SIZE;
512 
513 	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits)) {
514 		unsigned int cpp;
515 
516 		cpp = 1 << (PAGE_SHIFT - osb->s_clustersize_bits);
517 
518 		cluster_start = cpos % cpp;
519 		cluster_start = cluster_start << osb->s_clustersize_bits;
520 
521 		cluster_end = cluster_start + osb->s_clustersize;
522 	}
523 
524 	BUG_ON(cluster_start > PAGE_SIZE);
525 	BUG_ON(cluster_end > PAGE_SIZE);
526 
527 	if (start)
528 		*start = cluster_start;
529 	if (end)
530 		*end = cluster_end;
531 }
532 
533 /*
534  * 'from' and 'to' are the region in the page to avoid zeroing.
535  *
536  * If pagesize > clustersize, this function will avoid zeroing outside
537  * of the cluster boundary.
538  *
539  * from == to == 0 is code for "zero the entire cluster region"
540  */
ocfs2_clear_page_regions(struct page * page,struct ocfs2_super * osb,u32 cpos,unsigned from,unsigned to)541 static void ocfs2_clear_page_regions(struct page *page,
542 				     struct ocfs2_super *osb, u32 cpos,
543 				     unsigned from, unsigned to)
544 {
545 	void *kaddr;
546 	unsigned int cluster_start, cluster_end;
547 
548 	ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
549 
550 	kaddr = kmap_atomic(page);
551 
552 	if (from || to) {
553 		if (from > cluster_start)
554 			memset(kaddr + cluster_start, 0, from - cluster_start);
555 		if (to < cluster_end)
556 			memset(kaddr + to, 0, cluster_end - to);
557 	} else {
558 		memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
559 	}
560 
561 	kunmap_atomic(kaddr);
562 }
563 
564 /*
565  * Nonsparse file systems fully allocate before we get to the write
566  * code. This prevents ocfs2_write() from tagging the write as an
567  * allocating one, which means ocfs2_map_page_blocks() might try to
568  * read-in the blocks at the tail of our file. Avoid reading them by
569  * testing i_size against each block offset.
570  */
ocfs2_should_read_blk(struct inode * inode,struct page * page,unsigned int block_start)571 static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
572 				 unsigned int block_start)
573 {
574 	u64 offset = page_offset(page) + block_start;
575 
576 	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
577 		return 1;
578 
579 	if (i_size_read(inode) > offset)
580 		return 1;
581 
582 	return 0;
583 }
584 
585 /*
586  * Some of this taken from __block_write_begin(). We already have our
587  * mapping by now though, and the entire write will be allocating or
588  * it won't, so not much need to use BH_New.
589  *
590  * This will also skip zeroing, which is handled externally.
591  */
ocfs2_map_page_blocks(struct page * page,u64 * p_blkno,struct inode * inode,unsigned int from,unsigned int to,int new)592 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
593 			  struct inode *inode, unsigned int from,
594 			  unsigned int to, int new)
595 {
596 	int ret = 0;
597 	struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
598 	unsigned int block_end, block_start;
599 	unsigned int bsize = i_blocksize(inode);
600 
601 	if (!page_has_buffers(page))
602 		create_empty_buffers(page, bsize, 0);
603 
604 	head = page_buffers(page);
605 	for (bh = head, block_start = 0; bh != head || !block_start;
606 	     bh = bh->b_this_page, block_start += bsize) {
607 		block_end = block_start + bsize;
608 
609 		clear_buffer_new(bh);
610 
611 		/*
612 		 * Ignore blocks outside of our i/o range -
613 		 * they may belong to unallocated clusters.
614 		 */
615 		if (block_start >= to || block_end <= from) {
616 			if (PageUptodate(page))
617 				set_buffer_uptodate(bh);
618 			continue;
619 		}
620 
621 		/*
622 		 * For an allocating write with cluster size >= page
623 		 * size, we always write the entire page.
624 		 */
625 		if (new)
626 			set_buffer_new(bh);
627 
628 		if (!buffer_mapped(bh)) {
629 			map_bh(bh, inode->i_sb, *p_blkno);
630 			clean_bdev_bh_alias(bh);
631 		}
632 
633 		if (PageUptodate(page)) {
634 			set_buffer_uptodate(bh);
635 		} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
636 			   !buffer_new(bh) &&
637 			   ocfs2_should_read_blk(inode, page, block_start) &&
638 			   (block_start < from || block_end > to)) {
639 			bh_read_nowait(bh, 0);
640 			*wait_bh++=bh;
641 		}
642 
643 		*p_blkno = *p_blkno + 1;
644 	}
645 
646 	/*
647 	 * If we issued read requests - let them complete.
648 	 */
649 	while(wait_bh > wait) {
650 		wait_on_buffer(*--wait_bh);
651 		if (!buffer_uptodate(*wait_bh))
652 			ret = -EIO;
653 	}
654 
655 	if (ret == 0 || !new)
656 		return ret;
657 
658 	/*
659 	 * If we get -EIO above, zero out any newly allocated blocks
660 	 * to avoid exposing stale data.
661 	 */
662 	bh = head;
663 	block_start = 0;
664 	do {
665 		block_end = block_start + bsize;
666 		if (block_end <= from)
667 			goto next_bh;
668 		if (block_start >= to)
669 			break;
670 
671 		zero_user(page, block_start, bh->b_size);
672 		set_buffer_uptodate(bh);
673 		mark_buffer_dirty(bh);
674 
675 next_bh:
676 		block_start = block_end;
677 		bh = bh->b_this_page;
678 	} while (bh != head);
679 
680 	return ret;
681 }
682 
683 #if (PAGE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
684 #define OCFS2_MAX_CTXT_PAGES	1
685 #else
686 #define OCFS2_MAX_CTXT_PAGES	(OCFS2_MAX_CLUSTERSIZE / PAGE_SIZE)
687 #endif
688 
689 #define OCFS2_MAX_CLUSTERS_PER_PAGE	(PAGE_SIZE / OCFS2_MIN_CLUSTERSIZE)
690 
691 struct ocfs2_unwritten_extent {
692 	struct list_head	ue_node;
693 	struct list_head	ue_ip_node;
694 	u32			ue_cpos;
695 	u32			ue_phys;
696 };
697 
698 /*
699  * Describe the state of a single cluster to be written to.
700  */
701 struct ocfs2_write_cluster_desc {
702 	u32		c_cpos;
703 	u32		c_phys;
704 	/*
705 	 * Give this a unique field because c_phys eventually gets
706 	 * filled.
707 	 */
708 	unsigned	c_new;
709 	unsigned	c_clear_unwritten;
710 	unsigned	c_needs_zero;
711 };
712 
713 struct ocfs2_write_ctxt {
714 	/* Logical cluster position / len of write */
715 	u32				w_cpos;
716 	u32				w_clen;
717 
718 	/* First cluster allocated in a nonsparse extend */
719 	u32				w_first_new_cpos;
720 
721 	/* Type of caller. Must be one of buffer, mmap, direct.  */
722 	ocfs2_write_type_t		w_type;
723 
724 	struct ocfs2_write_cluster_desc	w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
725 
726 	/*
727 	 * This is true if page_size > cluster_size.
728 	 *
729 	 * It triggers a set of special cases during write which might
730 	 * have to deal with allocating writes to partial pages.
731 	 */
732 	unsigned int			w_large_pages;
733 
734 	/*
735 	 * Pages involved in this write.
736 	 *
737 	 * w_target_page is the page being written to by the user.
738 	 *
739 	 * w_pages is an array of pages which always contains
740 	 * w_target_page, and in the case of an allocating write with
741 	 * page_size < cluster size, it will contain zero'd and mapped
742 	 * pages adjacent to w_target_page which need to be written
743 	 * out in so that future reads from that region will get
744 	 * zero's.
745 	 */
746 	unsigned int			w_num_pages;
747 	struct page			*w_pages[OCFS2_MAX_CTXT_PAGES];
748 	struct page			*w_target_page;
749 
750 	/*
751 	 * w_target_locked is used for page_mkwrite path indicating no unlocking
752 	 * against w_target_page in ocfs2_write_end_nolock.
753 	 */
754 	unsigned int			w_target_locked:1;
755 
756 	/*
757 	 * ocfs2_write_end() uses this to know what the real range to
758 	 * write in the target should be.
759 	 */
760 	unsigned int			w_target_from;
761 	unsigned int			w_target_to;
762 
763 	/*
764 	 * We could use journal_current_handle() but this is cleaner,
765 	 * IMHO -Mark
766 	 */
767 	handle_t			*w_handle;
768 
769 	struct buffer_head		*w_di_bh;
770 
771 	struct ocfs2_cached_dealloc_ctxt w_dealloc;
772 
773 	struct list_head		w_unwritten_list;
774 	unsigned int			w_unwritten_count;
775 };
776 
ocfs2_unlock_and_free_pages(struct page ** pages,int num_pages)777 void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
778 {
779 	int i;
780 
781 	for(i = 0; i < num_pages; i++) {
782 		if (pages[i]) {
783 			unlock_page(pages[i]);
784 			mark_page_accessed(pages[i]);
785 			put_page(pages[i]);
786 		}
787 	}
788 }
789 
ocfs2_unlock_pages(struct ocfs2_write_ctxt * wc)790 static void ocfs2_unlock_pages(struct ocfs2_write_ctxt *wc)
791 {
792 	int i;
793 
794 	/*
795 	 * w_target_locked is only set to true in the page_mkwrite() case.
796 	 * The intent is to allow us to lock the target page from write_begin()
797 	 * to write_end(). The caller must hold a ref on w_target_page.
798 	 */
799 	if (wc->w_target_locked) {
800 		BUG_ON(!wc->w_target_page);
801 		for (i = 0; i < wc->w_num_pages; i++) {
802 			if (wc->w_target_page == wc->w_pages[i]) {
803 				wc->w_pages[i] = NULL;
804 				break;
805 			}
806 		}
807 		mark_page_accessed(wc->w_target_page);
808 		put_page(wc->w_target_page);
809 	}
810 	ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
811 }
812 
ocfs2_free_unwritten_list(struct inode * inode,struct list_head * head)813 static void ocfs2_free_unwritten_list(struct inode *inode,
814 				 struct list_head *head)
815 {
816 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
817 	struct ocfs2_unwritten_extent *ue = NULL, *tmp = NULL;
818 
819 	list_for_each_entry_safe(ue, tmp, head, ue_node) {
820 		list_del(&ue->ue_node);
821 		spin_lock(&oi->ip_lock);
822 		list_del(&ue->ue_ip_node);
823 		spin_unlock(&oi->ip_lock);
824 		kfree(ue);
825 	}
826 }
827 
ocfs2_free_write_ctxt(struct inode * inode,struct ocfs2_write_ctxt * wc)828 static void ocfs2_free_write_ctxt(struct inode *inode,
829 				  struct ocfs2_write_ctxt *wc)
830 {
831 	ocfs2_free_unwritten_list(inode, &wc->w_unwritten_list);
832 	ocfs2_unlock_pages(wc);
833 	brelse(wc->w_di_bh);
834 	kfree(wc);
835 }
836 
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)837 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
838 				  struct ocfs2_super *osb, loff_t pos,
839 				  unsigned len, ocfs2_write_type_t type,
840 				  struct buffer_head *di_bh)
841 {
842 	u32 cend;
843 	struct ocfs2_write_ctxt *wc;
844 
845 	wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
846 	if (!wc)
847 		return -ENOMEM;
848 
849 	wc->w_cpos = pos >> osb->s_clustersize_bits;
850 	wc->w_first_new_cpos = UINT_MAX;
851 	cend = (pos + len - 1) >> osb->s_clustersize_bits;
852 	wc->w_clen = cend - wc->w_cpos + 1;
853 	get_bh(di_bh);
854 	wc->w_di_bh = di_bh;
855 	wc->w_type = type;
856 
857 	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits))
858 		wc->w_large_pages = 1;
859 	else
860 		wc->w_large_pages = 0;
861 
862 	ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
863 	INIT_LIST_HEAD(&wc->w_unwritten_list);
864 
865 	*wcp = wc;
866 
867 	return 0;
868 }
869 
870 /*
871  * If a page has any new buffers, zero them out here, and mark them uptodate
872  * and dirty so they'll be written out (in order to prevent uninitialised
873  * block data from leaking). And clear the new bit.
874  */
ocfs2_zero_new_buffers(struct page * page,unsigned from,unsigned to)875 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
876 {
877 	unsigned int block_start, block_end;
878 	struct buffer_head *head, *bh;
879 
880 	BUG_ON(!PageLocked(page));
881 	if (!page_has_buffers(page))
882 		return;
883 
884 	bh = head = page_buffers(page);
885 	block_start = 0;
886 	do {
887 		block_end = block_start + bh->b_size;
888 
889 		if (buffer_new(bh)) {
890 			if (block_end > from && block_start < to) {
891 				if (!PageUptodate(page)) {
892 					unsigned start, end;
893 
894 					start = max(from, block_start);
895 					end = min(to, block_end);
896 
897 					zero_user_segment(page, start, end);
898 					set_buffer_uptodate(bh);
899 				}
900 
901 				clear_buffer_new(bh);
902 				mark_buffer_dirty(bh);
903 			}
904 		}
905 
906 		block_start = block_end;
907 		bh = bh->b_this_page;
908 	} while (bh != head);
909 }
910 
911 /*
912  * Only called when we have a failure during allocating write to write
913  * zero's to the newly allocated region.
914  */
ocfs2_write_failure(struct inode * inode,struct ocfs2_write_ctxt * wc,loff_t user_pos,unsigned user_len)915 static void ocfs2_write_failure(struct inode *inode,
916 				struct ocfs2_write_ctxt *wc,
917 				loff_t user_pos, unsigned user_len)
918 {
919 	int i;
920 	unsigned from = user_pos & (PAGE_SIZE - 1),
921 		to = user_pos + user_len;
922 	struct page *tmppage;
923 
924 	if (wc->w_target_page)
925 		ocfs2_zero_new_buffers(wc->w_target_page, from, to);
926 
927 	for(i = 0; i < wc->w_num_pages; i++) {
928 		tmppage = wc->w_pages[i];
929 
930 		if (tmppage && page_has_buffers(tmppage)) {
931 			if (ocfs2_should_order_data(inode))
932 				ocfs2_jbd2_inode_add_write(wc->w_handle, inode,
933 							   user_pos, user_len);
934 
935 			block_commit_write(tmppage, from, to);
936 		}
937 	}
938 }
939 
ocfs2_prepare_page_for_write(struct inode * inode,u64 * p_blkno,struct ocfs2_write_ctxt * wc,struct page * page,u32 cpos,loff_t user_pos,unsigned user_len,int new)940 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
941 					struct ocfs2_write_ctxt *wc,
942 					struct page *page, u32 cpos,
943 					loff_t user_pos, unsigned user_len,
944 					int new)
945 {
946 	int ret;
947 	unsigned int map_from = 0, map_to = 0;
948 	unsigned int cluster_start, cluster_end;
949 	unsigned int user_data_from = 0, user_data_to = 0;
950 
951 	ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
952 					&cluster_start, &cluster_end);
953 
954 	/* treat the write as new if the a hole/lseek spanned across
955 	 * the page boundary.
956 	 */
957 	new = new | ((i_size_read(inode) <= page_offset(page)) &&
958 			(page_offset(page) <= user_pos));
959 
960 	if (page == wc->w_target_page) {
961 		map_from = user_pos & (PAGE_SIZE - 1);
962 		map_to = map_from + user_len;
963 
964 		if (new)
965 			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
966 						    cluster_start, cluster_end,
967 						    new);
968 		else
969 			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
970 						    map_from, map_to, new);
971 		if (ret) {
972 			mlog_errno(ret);
973 			goto out;
974 		}
975 
976 		user_data_from = map_from;
977 		user_data_to = map_to;
978 		if (new) {
979 			map_from = cluster_start;
980 			map_to = cluster_end;
981 		}
982 	} else {
983 		/*
984 		 * If we haven't allocated the new page yet, we
985 		 * shouldn't be writing it out without copying user
986 		 * data. This is likely a math error from the caller.
987 		 */
988 		BUG_ON(!new);
989 
990 		map_from = cluster_start;
991 		map_to = cluster_end;
992 
993 		ret = ocfs2_map_page_blocks(page, p_blkno, inode,
994 					    cluster_start, cluster_end, new);
995 		if (ret) {
996 			mlog_errno(ret);
997 			goto out;
998 		}
999 	}
1000 
1001 	/*
1002 	 * Parts of newly allocated pages need to be zero'd.
1003 	 *
1004 	 * Above, we have also rewritten 'to' and 'from' - as far as
1005 	 * the rest of the function is concerned, the entire cluster
1006 	 * range inside of a page needs to be written.
1007 	 *
1008 	 * We can skip this if the page is up to date - it's already
1009 	 * been zero'd from being read in as a hole.
1010 	 */
1011 	if (new && !PageUptodate(page))
1012 		ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1013 					 cpos, user_data_from, user_data_to);
1014 
1015 	flush_dcache_page(page);
1016 
1017 out:
1018 	return ret;
1019 }
1020 
1021 /*
1022  * This function will only grab one clusters worth of pages.
1023  */
ocfs2_grab_pages_for_write(struct address_space * mapping,struct ocfs2_write_ctxt * wc,u32 cpos,loff_t user_pos,unsigned user_len,int new,struct page * mmap_page)1024 static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1025 				      struct ocfs2_write_ctxt *wc,
1026 				      u32 cpos, loff_t user_pos,
1027 				      unsigned user_len, int new,
1028 				      struct page *mmap_page)
1029 {
1030 	int ret = 0, i;
1031 	unsigned long start, target_index, end_index, index;
1032 	struct inode *inode = mapping->host;
1033 	loff_t last_byte;
1034 
1035 	target_index = user_pos >> PAGE_SHIFT;
1036 
1037 	/*
1038 	 * Figure out how many pages we'll be manipulating here. For
1039 	 * non allocating write, we just change the one
1040 	 * page. Otherwise, we'll need a whole clusters worth.  If we're
1041 	 * writing past i_size, we only need enough pages to cover the
1042 	 * last page of the write.
1043 	 */
1044 	if (new) {
1045 		wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1046 		start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1047 		/*
1048 		 * We need the index *past* the last page we could possibly
1049 		 * touch.  This is the page past the end of the write or
1050 		 * i_size, whichever is greater.
1051 		 */
1052 		last_byte = max(user_pos + user_len, i_size_read(inode));
1053 		BUG_ON(last_byte < 1);
1054 		end_index = ((last_byte - 1) >> PAGE_SHIFT) + 1;
1055 		if ((start + wc->w_num_pages) > end_index)
1056 			wc->w_num_pages = end_index - start;
1057 	} else {
1058 		wc->w_num_pages = 1;
1059 		start = target_index;
1060 	}
1061 	end_index = (user_pos + user_len - 1) >> PAGE_SHIFT;
1062 
1063 	for(i = 0; i < wc->w_num_pages; i++) {
1064 		index = start + i;
1065 
1066 		if (index >= target_index && index <= end_index &&
1067 		    wc->w_type == OCFS2_WRITE_MMAP) {
1068 			/*
1069 			 * ocfs2_pagemkwrite() is a little different
1070 			 * and wants us to directly use the page
1071 			 * passed in.
1072 			 */
1073 			lock_page(mmap_page);
1074 
1075 			/* Exit and let the caller retry */
1076 			if (mmap_page->mapping != mapping) {
1077 				WARN_ON(mmap_page->mapping);
1078 				unlock_page(mmap_page);
1079 				ret = -EAGAIN;
1080 				goto out;
1081 			}
1082 
1083 			get_page(mmap_page);
1084 			wc->w_pages[i] = mmap_page;
1085 			wc->w_target_locked = true;
1086 		} else if (index >= target_index && index <= end_index &&
1087 			   wc->w_type == OCFS2_WRITE_DIRECT) {
1088 			/* Direct write has no mapping page. */
1089 			wc->w_pages[i] = NULL;
1090 			continue;
1091 		} else {
1092 			wc->w_pages[i] = find_or_create_page(mapping, index,
1093 							     GFP_NOFS);
1094 			if (!wc->w_pages[i]) {
1095 				ret = -ENOMEM;
1096 				mlog_errno(ret);
1097 				goto out;
1098 			}
1099 		}
1100 		wait_for_stable_page(wc->w_pages[i]);
1101 
1102 		if (index == target_index)
1103 			wc->w_target_page = wc->w_pages[i];
1104 	}
1105 out:
1106 	if (ret)
1107 		wc->w_target_locked = false;
1108 	return ret;
1109 }
1110 
1111 /*
1112  * Prepare a single cluster for write one cluster into the file.
1113  */
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)1114 static int ocfs2_write_cluster(struct address_space *mapping,
1115 			       u32 *phys, unsigned int new,
1116 			       unsigned int clear_unwritten,
1117 			       unsigned int should_zero,
1118 			       struct ocfs2_alloc_context *data_ac,
1119 			       struct ocfs2_alloc_context *meta_ac,
1120 			       struct ocfs2_write_ctxt *wc, u32 cpos,
1121 			       loff_t user_pos, unsigned user_len)
1122 {
1123 	int ret, i;
1124 	u64 p_blkno;
1125 	struct inode *inode = mapping->host;
1126 	struct ocfs2_extent_tree et;
1127 	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
1128 
1129 	if (new) {
1130 		u32 tmp_pos;
1131 
1132 		/*
1133 		 * This is safe to call with the page locks - it won't take
1134 		 * any additional semaphores or cluster locks.
1135 		 */
1136 		tmp_pos = cpos;
1137 		ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1138 					   &tmp_pos, 1, !clear_unwritten,
1139 					   wc->w_di_bh, wc->w_handle,
1140 					   data_ac, meta_ac, NULL);
1141 		/*
1142 		 * This shouldn't happen because we must have already
1143 		 * calculated the correct meta data allocation required. The
1144 		 * internal tree allocation code should know how to increase
1145 		 * transaction credits itself.
1146 		 *
1147 		 * If need be, we could handle -EAGAIN for a
1148 		 * RESTART_TRANS here.
1149 		 */
1150 		mlog_bug_on_msg(ret == -EAGAIN,
1151 				"Inode %llu: EAGAIN return during allocation.\n",
1152 				(unsigned long long)OCFS2_I(inode)->ip_blkno);
1153 		if (ret < 0) {
1154 			mlog_errno(ret);
1155 			goto out;
1156 		}
1157 	} else if (clear_unwritten) {
1158 		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1159 					      wc->w_di_bh);
1160 		ret = ocfs2_mark_extent_written(inode, &et,
1161 						wc->w_handle, cpos, 1, *phys,
1162 						meta_ac, &wc->w_dealloc);
1163 		if (ret < 0) {
1164 			mlog_errno(ret);
1165 			goto out;
1166 		}
1167 	}
1168 
1169 	/*
1170 	 * The only reason this should fail is due to an inability to
1171 	 * find the extent added.
1172 	 */
1173 	ret = ocfs2_get_clusters(inode, cpos, phys, NULL, NULL);
1174 	if (ret < 0) {
1175 		mlog(ML_ERROR, "Get physical blkno failed for inode %llu, "
1176 			    "at logical cluster %u",
1177 			    (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos);
1178 		goto out;
1179 	}
1180 
1181 	BUG_ON(*phys == 0);
1182 
1183 	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, *phys);
1184 	if (!should_zero)
1185 		p_blkno += (user_pos >> inode->i_sb->s_blocksize_bits) & (u64)(bpc - 1);
1186 
1187 	for(i = 0; i < wc->w_num_pages; i++) {
1188 		int tmpret;
1189 
1190 		/* This is the direct io target page. */
1191 		if (wc->w_pages[i] == NULL) {
1192 			p_blkno++;
1193 			continue;
1194 		}
1195 
1196 		tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1197 						      wc->w_pages[i], cpos,
1198 						      user_pos, user_len,
1199 						      should_zero);
1200 		if (tmpret) {
1201 			mlog_errno(tmpret);
1202 			if (ret == 0)
1203 				ret = tmpret;
1204 		}
1205 	}
1206 
1207 	/*
1208 	 * We only have cleanup to do in case of allocating write.
1209 	 */
1210 	if (ret && new)
1211 		ocfs2_write_failure(inode, wc, user_pos, user_len);
1212 
1213 out:
1214 
1215 	return ret;
1216 }
1217 
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)1218 static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1219 				       struct ocfs2_alloc_context *data_ac,
1220 				       struct ocfs2_alloc_context *meta_ac,
1221 				       struct ocfs2_write_ctxt *wc,
1222 				       loff_t pos, unsigned len)
1223 {
1224 	int ret, i;
1225 	loff_t cluster_off;
1226 	unsigned int local_len = len;
1227 	struct ocfs2_write_cluster_desc *desc;
1228 	struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1229 
1230 	for (i = 0; i < wc->w_clen; i++) {
1231 		desc = &wc->w_desc[i];
1232 
1233 		/*
1234 		 * We have to make sure that the total write passed in
1235 		 * doesn't extend past a single cluster.
1236 		 */
1237 		local_len = len;
1238 		cluster_off = pos & (osb->s_clustersize - 1);
1239 		if ((cluster_off + local_len) > osb->s_clustersize)
1240 			local_len = osb->s_clustersize - cluster_off;
1241 
1242 		ret = ocfs2_write_cluster(mapping, &desc->c_phys,
1243 					  desc->c_new,
1244 					  desc->c_clear_unwritten,
1245 					  desc->c_needs_zero,
1246 					  data_ac, meta_ac,
1247 					  wc, desc->c_cpos, pos, local_len);
1248 		if (ret) {
1249 			mlog_errno(ret);
1250 			goto out;
1251 		}
1252 
1253 		len -= local_len;
1254 		pos += local_len;
1255 	}
1256 
1257 	ret = 0;
1258 out:
1259 	return ret;
1260 }
1261 
1262 /*
1263  * ocfs2_write_end() wants to know which parts of the target page it
1264  * should complete the write on. It's easiest to compute them ahead of
1265  * time when a more complete view of the write is available.
1266  */
ocfs2_set_target_boundaries(struct ocfs2_super * osb,struct ocfs2_write_ctxt * wc,loff_t pos,unsigned len,int alloc)1267 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1268 					struct ocfs2_write_ctxt *wc,
1269 					loff_t pos, unsigned len, int alloc)
1270 {
1271 	struct ocfs2_write_cluster_desc *desc;
1272 
1273 	wc->w_target_from = pos & (PAGE_SIZE - 1);
1274 	wc->w_target_to = wc->w_target_from + len;
1275 
1276 	if (alloc == 0)
1277 		return;
1278 
1279 	/*
1280 	 * Allocating write - we may have different boundaries based
1281 	 * on page size and cluster size.
1282 	 *
1283 	 * NOTE: We can no longer compute one value from the other as
1284 	 * the actual write length and user provided length may be
1285 	 * different.
1286 	 */
1287 
1288 	if (wc->w_large_pages) {
1289 		/*
1290 		 * We only care about the 1st and last cluster within
1291 		 * our range and whether they should be zero'd or not. Either
1292 		 * value may be extended out to the start/end of a
1293 		 * newly allocated cluster.
1294 		 */
1295 		desc = &wc->w_desc[0];
1296 		if (desc->c_needs_zero)
1297 			ocfs2_figure_cluster_boundaries(osb,
1298 							desc->c_cpos,
1299 							&wc->w_target_from,
1300 							NULL);
1301 
1302 		desc = &wc->w_desc[wc->w_clen - 1];
1303 		if (desc->c_needs_zero)
1304 			ocfs2_figure_cluster_boundaries(osb,
1305 							desc->c_cpos,
1306 							NULL,
1307 							&wc->w_target_to);
1308 	} else {
1309 		wc->w_target_from = 0;
1310 		wc->w_target_to = PAGE_SIZE;
1311 	}
1312 }
1313 
1314 /*
1315  * Check if this extent is marked UNWRITTEN by direct io. If so, we need not to
1316  * do the zero work. And should not to clear UNWRITTEN since it will be cleared
1317  * by the direct io procedure.
1318  * If this is a new extent that allocated by direct io, we should mark it in
1319  * the ip_unwritten_list.
1320  */
ocfs2_unwritten_check(struct inode * inode,struct ocfs2_write_ctxt * wc,struct ocfs2_write_cluster_desc * desc)1321 static int ocfs2_unwritten_check(struct inode *inode,
1322 				 struct ocfs2_write_ctxt *wc,
1323 				 struct ocfs2_write_cluster_desc *desc)
1324 {
1325 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1326 	struct ocfs2_unwritten_extent *ue = NULL, *new = NULL;
1327 	int ret = 0;
1328 
1329 	if (!desc->c_needs_zero)
1330 		return 0;
1331 
1332 retry:
1333 	spin_lock(&oi->ip_lock);
1334 	/* Needs not to zero no metter buffer or direct. The one who is zero
1335 	 * the cluster is doing zero. And he will clear unwritten after all
1336 	 * cluster io finished. */
1337 	list_for_each_entry(ue, &oi->ip_unwritten_list, ue_ip_node) {
1338 		if (desc->c_cpos == ue->ue_cpos) {
1339 			BUG_ON(desc->c_new);
1340 			desc->c_needs_zero = 0;
1341 			desc->c_clear_unwritten = 0;
1342 			goto unlock;
1343 		}
1344 	}
1345 
1346 	if (wc->w_type != OCFS2_WRITE_DIRECT)
1347 		goto unlock;
1348 
1349 	if (new == NULL) {
1350 		spin_unlock(&oi->ip_lock);
1351 		new = kmalloc(sizeof(struct ocfs2_unwritten_extent),
1352 			     GFP_NOFS);
1353 		if (new == NULL) {
1354 			ret = -ENOMEM;
1355 			goto out;
1356 		}
1357 		goto retry;
1358 	}
1359 	/* This direct write will doing zero. */
1360 	new->ue_cpos = desc->c_cpos;
1361 	new->ue_phys = desc->c_phys;
1362 	desc->c_clear_unwritten = 0;
1363 	list_add_tail(&new->ue_ip_node, &oi->ip_unwritten_list);
1364 	list_add_tail(&new->ue_node, &wc->w_unwritten_list);
1365 	wc->w_unwritten_count++;
1366 	new = NULL;
1367 unlock:
1368 	spin_unlock(&oi->ip_lock);
1369 out:
1370 	kfree(new);
1371 	return ret;
1372 }
1373 
1374 /*
1375  * Populate each single-cluster write descriptor in the write context
1376  * with information about the i/o to be done.
1377  *
1378  * Returns the number of clusters that will have to be allocated, as
1379  * well as a worst case estimate of the number of extent records that
1380  * would have to be created during a write to an unwritten region.
1381  */
ocfs2_populate_write_desc(struct inode * inode,struct ocfs2_write_ctxt * wc,unsigned int * clusters_to_alloc,unsigned int * extents_to_split)1382 static int ocfs2_populate_write_desc(struct inode *inode,
1383 				     struct ocfs2_write_ctxt *wc,
1384 				     unsigned int *clusters_to_alloc,
1385 				     unsigned int *extents_to_split)
1386 {
1387 	int ret;
1388 	struct ocfs2_write_cluster_desc *desc;
1389 	unsigned int num_clusters = 0;
1390 	unsigned int ext_flags = 0;
1391 	u32 phys = 0;
1392 	int i;
1393 
1394 	*clusters_to_alloc = 0;
1395 	*extents_to_split = 0;
1396 
1397 	for (i = 0; i < wc->w_clen; i++) {
1398 		desc = &wc->w_desc[i];
1399 		desc->c_cpos = wc->w_cpos + i;
1400 
1401 		if (num_clusters == 0) {
1402 			/*
1403 			 * Need to look up the next extent record.
1404 			 */
1405 			ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1406 						 &num_clusters, &ext_flags);
1407 			if (ret) {
1408 				mlog_errno(ret);
1409 				goto out;
1410 			}
1411 
1412 			/* We should already CoW the refcountd extent. */
1413 			BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1414 
1415 			/*
1416 			 * Assume worst case - that we're writing in
1417 			 * the middle of the extent.
1418 			 *
1419 			 * We can assume that the write proceeds from
1420 			 * left to right, in which case the extent
1421 			 * insert code is smart enough to coalesce the
1422 			 * next splits into the previous records created.
1423 			 */
1424 			if (ext_flags & OCFS2_EXT_UNWRITTEN)
1425 				*extents_to_split = *extents_to_split + 2;
1426 		} else if (phys) {
1427 			/*
1428 			 * Only increment phys if it doesn't describe
1429 			 * a hole.
1430 			 */
1431 			phys++;
1432 		}
1433 
1434 		/*
1435 		 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1436 		 * file that got extended.  w_first_new_cpos tells us
1437 		 * where the newly allocated clusters are so we can
1438 		 * zero them.
1439 		 */
1440 		if (desc->c_cpos >= wc->w_first_new_cpos) {
1441 			BUG_ON(phys == 0);
1442 			desc->c_needs_zero = 1;
1443 		}
1444 
1445 		desc->c_phys = phys;
1446 		if (phys == 0) {
1447 			desc->c_new = 1;
1448 			desc->c_needs_zero = 1;
1449 			desc->c_clear_unwritten = 1;
1450 			*clusters_to_alloc = *clusters_to_alloc + 1;
1451 		}
1452 
1453 		if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1454 			desc->c_clear_unwritten = 1;
1455 			desc->c_needs_zero = 1;
1456 		}
1457 
1458 		ret = ocfs2_unwritten_check(inode, wc, desc);
1459 		if (ret) {
1460 			mlog_errno(ret);
1461 			goto out;
1462 		}
1463 
1464 		num_clusters--;
1465 	}
1466 
1467 	ret = 0;
1468 out:
1469 	return ret;
1470 }
1471 
ocfs2_write_begin_inline(struct address_space * mapping,struct inode * inode,struct ocfs2_write_ctxt * wc)1472 static int ocfs2_write_begin_inline(struct address_space *mapping,
1473 				    struct inode *inode,
1474 				    struct ocfs2_write_ctxt *wc)
1475 {
1476 	int ret;
1477 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1478 	struct page *page;
1479 	handle_t *handle;
1480 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1481 
1482 	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1483 	if (IS_ERR(handle)) {
1484 		ret = PTR_ERR(handle);
1485 		mlog_errno(ret);
1486 		goto out;
1487 	}
1488 
1489 	page = find_or_create_page(mapping, 0, GFP_NOFS);
1490 	if (!page) {
1491 		ocfs2_commit_trans(osb, handle);
1492 		ret = -ENOMEM;
1493 		mlog_errno(ret);
1494 		goto out;
1495 	}
1496 	/*
1497 	 * If we don't set w_num_pages then this page won't get unlocked
1498 	 * and freed on cleanup of the write context.
1499 	 */
1500 	wc->w_pages[0] = wc->w_target_page = page;
1501 	wc->w_num_pages = 1;
1502 
1503 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1504 				      OCFS2_JOURNAL_ACCESS_WRITE);
1505 	if (ret) {
1506 		ocfs2_commit_trans(osb, handle);
1507 
1508 		mlog_errno(ret);
1509 		goto out;
1510 	}
1511 
1512 	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1513 		ocfs2_set_inode_data_inline(inode, di);
1514 
1515 	if (!PageUptodate(page)) {
1516 		ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1517 		if (ret) {
1518 			ocfs2_commit_trans(osb, handle);
1519 
1520 			goto out;
1521 		}
1522 	}
1523 
1524 	wc->w_handle = handle;
1525 out:
1526 	return ret;
1527 }
1528 
ocfs2_size_fits_inline_data(struct buffer_head * di_bh,u64 new_size)1529 int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1530 {
1531 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1532 
1533 	if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1534 		return 1;
1535 	return 0;
1536 }
1537 
ocfs2_try_to_write_inline_data(struct address_space * mapping,struct inode * inode,loff_t pos,unsigned len,struct page * mmap_page,struct ocfs2_write_ctxt * wc)1538 static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1539 					  struct inode *inode, loff_t pos,
1540 					  unsigned len, struct page *mmap_page,
1541 					  struct ocfs2_write_ctxt *wc)
1542 {
1543 	int ret, written = 0;
1544 	loff_t end = pos + len;
1545 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1546 	struct ocfs2_dinode *di = NULL;
1547 
1548 	trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1549 					     len, (unsigned long long)pos,
1550 					     oi->ip_dyn_features);
1551 
1552 	/*
1553 	 * Handle inodes which already have inline data 1st.
1554 	 */
1555 	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1556 		if (mmap_page == NULL &&
1557 		    ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1558 			goto do_inline_write;
1559 
1560 		/*
1561 		 * The write won't fit - we have to give this inode an
1562 		 * inline extent list now.
1563 		 */
1564 		ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1565 		if (ret)
1566 			mlog_errno(ret);
1567 		goto out;
1568 	}
1569 
1570 	/*
1571 	 * Check whether the inode can accept inline data.
1572 	 */
1573 	if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1574 		return 0;
1575 
1576 	/*
1577 	 * Check whether the write can fit.
1578 	 */
1579 	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1580 	if (mmap_page ||
1581 	    end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1582 		return 0;
1583 
1584 do_inline_write:
1585 	ret = ocfs2_write_begin_inline(mapping, inode, wc);
1586 	if (ret) {
1587 		mlog_errno(ret);
1588 		goto out;
1589 	}
1590 
1591 	/*
1592 	 * This signals to the caller that the data can be written
1593 	 * inline.
1594 	 */
1595 	written = 1;
1596 out:
1597 	return written ? written : ret;
1598 }
1599 
1600 /*
1601  * This function only does anything for file systems which can't
1602  * handle sparse files.
1603  *
1604  * What we want to do here is fill in any hole between the current end
1605  * of allocation and the end of our write. That way the rest of the
1606  * write path can treat it as an non-allocating write, which has no
1607  * special case code for sparse/nonsparse files.
1608  */
ocfs2_expand_nonsparse_inode(struct inode * inode,struct buffer_head * di_bh,loff_t pos,unsigned len,struct ocfs2_write_ctxt * wc)1609 static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1610 					struct buffer_head *di_bh,
1611 					loff_t pos, unsigned len,
1612 					struct ocfs2_write_ctxt *wc)
1613 {
1614 	int ret;
1615 	loff_t newsize = pos + len;
1616 
1617 	BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1618 
1619 	if (newsize <= i_size_read(inode))
1620 		return 0;
1621 
1622 	ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1623 	if (ret)
1624 		mlog_errno(ret);
1625 
1626 	/* There is no wc if this is call from direct. */
1627 	if (wc)
1628 		wc->w_first_new_cpos =
1629 			ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1630 
1631 	return ret;
1632 }
1633 
ocfs2_zero_tail(struct inode * inode,struct buffer_head * di_bh,loff_t pos)1634 static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1635 			   loff_t pos)
1636 {
1637 	int ret = 0;
1638 
1639 	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1640 	if (pos > i_size_read(inode))
1641 		ret = ocfs2_zero_extend(inode, di_bh, pos);
1642 
1643 	return ret;
1644 }
1645 
ocfs2_write_begin_nolock(struct address_space * mapping,loff_t pos,unsigned len,ocfs2_write_type_t type,struct page ** pagep,void ** fsdata,struct buffer_head * di_bh,struct page * mmap_page)1646 int ocfs2_write_begin_nolock(struct address_space *mapping,
1647 			     loff_t pos, unsigned len, ocfs2_write_type_t type,
1648 			     struct page **pagep, void **fsdata,
1649 			     struct buffer_head *di_bh, struct page *mmap_page)
1650 {
1651 	int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1652 	unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1653 	struct ocfs2_write_ctxt *wc;
1654 	struct inode *inode = mapping->host;
1655 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1656 	struct ocfs2_dinode *di;
1657 	struct ocfs2_alloc_context *data_ac = NULL;
1658 	struct ocfs2_alloc_context *meta_ac = NULL;
1659 	handle_t *handle;
1660 	struct ocfs2_extent_tree et;
1661 	int try_free = 1, ret1;
1662 
1663 try_again:
1664 	ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, type, di_bh);
1665 	if (ret) {
1666 		mlog_errno(ret);
1667 		return ret;
1668 	}
1669 
1670 	if (ocfs2_supports_inline_data(osb)) {
1671 		ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1672 						     mmap_page, wc);
1673 		if (ret == 1) {
1674 			ret = 0;
1675 			goto success;
1676 		}
1677 		if (ret < 0) {
1678 			mlog_errno(ret);
1679 			goto out;
1680 		}
1681 	}
1682 
1683 	/* Direct io change i_size late, should not zero tail here. */
1684 	if (type != OCFS2_WRITE_DIRECT) {
1685 		if (ocfs2_sparse_alloc(osb))
1686 			ret = ocfs2_zero_tail(inode, di_bh, pos);
1687 		else
1688 			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
1689 							   len, wc);
1690 		if (ret) {
1691 			mlog_errno(ret);
1692 			goto out;
1693 		}
1694 	}
1695 
1696 	ret = ocfs2_check_range_for_refcount(inode, pos, len);
1697 	if (ret < 0) {
1698 		mlog_errno(ret);
1699 		goto out;
1700 	} else if (ret == 1) {
1701 		clusters_need = wc->w_clen;
1702 		ret = ocfs2_refcount_cow(inode, di_bh,
1703 					 wc->w_cpos, wc->w_clen, UINT_MAX);
1704 		if (ret) {
1705 			mlog_errno(ret);
1706 			goto out;
1707 		}
1708 	}
1709 
1710 	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1711 					&extents_to_split);
1712 	if (ret) {
1713 		mlog_errno(ret);
1714 		goto out;
1715 	}
1716 	clusters_need += clusters_to_alloc;
1717 
1718 	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1719 
1720 	trace_ocfs2_write_begin_nolock(
1721 			(unsigned long long)OCFS2_I(inode)->ip_blkno,
1722 			(long long)i_size_read(inode),
1723 			le32_to_cpu(di->i_clusters),
1724 			pos, len, type, mmap_page,
1725 			clusters_to_alloc, extents_to_split);
1726 
1727 	/*
1728 	 * We set w_target_from, w_target_to here so that
1729 	 * ocfs2_write_end() knows which range in the target page to
1730 	 * write out. An allocation requires that we write the entire
1731 	 * cluster range.
1732 	 */
1733 	if (clusters_to_alloc || extents_to_split) {
1734 		/*
1735 		 * XXX: We are stretching the limits of
1736 		 * ocfs2_lock_allocators(). It greatly over-estimates
1737 		 * the work to be done.
1738 		 */
1739 		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1740 					      wc->w_di_bh);
1741 		ret = ocfs2_lock_allocators(inode, &et,
1742 					    clusters_to_alloc, extents_to_split,
1743 					    &data_ac, &meta_ac);
1744 		if (ret) {
1745 			mlog_errno(ret);
1746 			goto out;
1747 		}
1748 
1749 		if (data_ac)
1750 			data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1751 
1752 		credits = ocfs2_calc_extend_credits(inode->i_sb,
1753 						    &di->id2.i_list);
1754 	} else if (type == OCFS2_WRITE_DIRECT)
1755 		/* direct write needs not to start trans if no extents alloc. */
1756 		goto success;
1757 
1758 	/*
1759 	 * We have to zero sparse allocated clusters, unwritten extent clusters,
1760 	 * and non-sparse clusters we just extended.  For non-sparse writes,
1761 	 * we know zeros will only be needed in the first and/or last cluster.
1762 	 */
1763 	if (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1764 			   wc->w_desc[wc->w_clen - 1].c_needs_zero))
1765 		cluster_of_pages = 1;
1766 	else
1767 		cluster_of_pages = 0;
1768 
1769 	ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1770 
1771 	handle = ocfs2_start_trans(osb, credits);
1772 	if (IS_ERR(handle)) {
1773 		ret = PTR_ERR(handle);
1774 		mlog_errno(ret);
1775 		goto out;
1776 	}
1777 
1778 	wc->w_handle = handle;
1779 
1780 	if (clusters_to_alloc) {
1781 		ret = dquot_alloc_space_nodirty(inode,
1782 			ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1783 		if (ret)
1784 			goto out_commit;
1785 	}
1786 
1787 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1788 				      OCFS2_JOURNAL_ACCESS_WRITE);
1789 	if (ret) {
1790 		mlog_errno(ret);
1791 		goto out_quota;
1792 	}
1793 
1794 	/*
1795 	 * Fill our page array first. That way we've grabbed enough so
1796 	 * that we can zero and flush if we error after adding the
1797 	 * extent.
1798 	 */
1799 	ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
1800 					 cluster_of_pages, mmap_page);
1801 	if (ret) {
1802 		/*
1803 		 * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock
1804 		 * the target page. In this case, we exit with no error and no target
1805 		 * page. This will trigger the caller, page_mkwrite(), to re-try
1806 		 * the operation.
1807 		 */
1808 		if (type == OCFS2_WRITE_MMAP && ret == -EAGAIN) {
1809 			BUG_ON(wc->w_target_page);
1810 			ret = 0;
1811 			goto out_quota;
1812 		}
1813 
1814 		mlog_errno(ret);
1815 		goto out_quota;
1816 	}
1817 
1818 	ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1819 					  len);
1820 	if (ret) {
1821 		mlog_errno(ret);
1822 		goto out_quota;
1823 	}
1824 
1825 	if (data_ac)
1826 		ocfs2_free_alloc_context(data_ac);
1827 	if (meta_ac)
1828 		ocfs2_free_alloc_context(meta_ac);
1829 
1830 success:
1831 	if (pagep)
1832 		*pagep = wc->w_target_page;
1833 	*fsdata = wc;
1834 	return 0;
1835 out_quota:
1836 	if (clusters_to_alloc)
1837 		dquot_free_space(inode,
1838 			  ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1839 out_commit:
1840 	ocfs2_commit_trans(osb, handle);
1841 
1842 out:
1843 	/*
1844 	 * The mmapped page won't be unlocked in ocfs2_free_write_ctxt(),
1845 	 * even in case of error here like ENOSPC and ENOMEM. So, we need
1846 	 * to unlock the target page manually to prevent deadlocks when
1847 	 * retrying again on ENOSPC, or when returning non-VM_FAULT_LOCKED
1848 	 * to VM code.
1849 	 */
1850 	if (wc->w_target_locked)
1851 		unlock_page(mmap_page);
1852 
1853 	ocfs2_free_write_ctxt(inode, wc);
1854 
1855 	if (data_ac) {
1856 		ocfs2_free_alloc_context(data_ac);
1857 		data_ac = NULL;
1858 	}
1859 	if (meta_ac) {
1860 		ocfs2_free_alloc_context(meta_ac);
1861 		meta_ac = NULL;
1862 	}
1863 
1864 	if (ret == -ENOSPC && try_free) {
1865 		/*
1866 		 * Try to free some truncate log so that we can have enough
1867 		 * clusters to allocate.
1868 		 */
1869 		try_free = 0;
1870 
1871 		ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1872 		if (ret1 == 1)
1873 			goto try_again;
1874 
1875 		if (ret1 < 0)
1876 			mlog_errno(ret1);
1877 	}
1878 
1879 	return ret;
1880 }
1881 
ocfs2_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,struct page ** pagep,void ** fsdata)1882 static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1883 			     loff_t pos, unsigned len,
1884 			     struct page **pagep, void **fsdata)
1885 {
1886 	int ret;
1887 	struct buffer_head *di_bh = NULL;
1888 	struct inode *inode = mapping->host;
1889 
1890 	ret = ocfs2_inode_lock(inode, &di_bh, 1);
1891 	if (ret) {
1892 		mlog_errno(ret);
1893 		return ret;
1894 	}
1895 
1896 	/*
1897 	 * Take alloc sem here to prevent concurrent lookups. That way
1898 	 * the mapping, zeroing and tree manipulation within
1899 	 * ocfs2_write() will be safe against ->read_folio(). This
1900 	 * should also serve to lock out allocation from a shared
1901 	 * writeable region.
1902 	 */
1903 	down_write(&OCFS2_I(inode)->ip_alloc_sem);
1904 
1905 	ret = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_BUFFER,
1906 				       pagep, fsdata, di_bh, NULL);
1907 	if (ret) {
1908 		mlog_errno(ret);
1909 		goto out_fail;
1910 	}
1911 
1912 	brelse(di_bh);
1913 
1914 	return 0;
1915 
1916 out_fail:
1917 	up_write(&OCFS2_I(inode)->ip_alloc_sem);
1918 
1919 	brelse(di_bh);
1920 	ocfs2_inode_unlock(inode, 1);
1921 
1922 	return ret;
1923 }
1924 
ocfs2_write_end_inline(struct inode * inode,loff_t pos,unsigned len,unsigned * copied,struct ocfs2_dinode * di,struct ocfs2_write_ctxt * wc)1925 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1926 				   unsigned len, unsigned *copied,
1927 				   struct ocfs2_dinode *di,
1928 				   struct ocfs2_write_ctxt *wc)
1929 {
1930 	void *kaddr;
1931 
1932 	if (unlikely(*copied < len)) {
1933 		if (!PageUptodate(wc->w_target_page)) {
1934 			*copied = 0;
1935 			return;
1936 		}
1937 	}
1938 
1939 	kaddr = kmap_atomic(wc->w_target_page);
1940 	memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1941 	kunmap_atomic(kaddr);
1942 
1943 	trace_ocfs2_write_end_inline(
1944 	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1945 	     (unsigned long long)pos, *copied,
1946 	     le16_to_cpu(di->id2.i_data.id_count),
1947 	     le16_to_cpu(di->i_dyn_features));
1948 }
1949 
ocfs2_write_end_nolock(struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,void * fsdata)1950 int ocfs2_write_end_nolock(struct address_space *mapping,
1951 			   loff_t pos, unsigned len, unsigned copied, void *fsdata)
1952 {
1953 	int i, ret;
1954 	unsigned from, to, start = pos & (PAGE_SIZE - 1);
1955 	struct inode *inode = mapping->host;
1956 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1957 	struct ocfs2_write_ctxt *wc = fsdata;
1958 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1959 	handle_t *handle = wc->w_handle;
1960 	struct page *tmppage;
1961 
1962 	BUG_ON(!list_empty(&wc->w_unwritten_list));
1963 
1964 	if (handle) {
1965 		ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode),
1966 				wc->w_di_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1967 		if (ret) {
1968 			copied = ret;
1969 			mlog_errno(ret);
1970 			goto out;
1971 		}
1972 	}
1973 
1974 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1975 		ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1976 		goto out_write_size;
1977 	}
1978 
1979 	if (unlikely(copied < len) && wc->w_target_page) {
1980 		if (!PageUptodate(wc->w_target_page))
1981 			copied = 0;
1982 
1983 		ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1984 				       start+len);
1985 	}
1986 	if (wc->w_target_page)
1987 		flush_dcache_page(wc->w_target_page);
1988 
1989 	for(i = 0; i < wc->w_num_pages; i++) {
1990 		tmppage = wc->w_pages[i];
1991 
1992 		/* This is the direct io target page. */
1993 		if (tmppage == NULL)
1994 			continue;
1995 
1996 		if (tmppage == wc->w_target_page) {
1997 			from = wc->w_target_from;
1998 			to = wc->w_target_to;
1999 
2000 			BUG_ON(from > PAGE_SIZE ||
2001 			       to > PAGE_SIZE ||
2002 			       to < from);
2003 		} else {
2004 			/*
2005 			 * Pages adjacent to the target (if any) imply
2006 			 * a hole-filling write in which case we want
2007 			 * to flush their entire range.
2008 			 */
2009 			from = 0;
2010 			to = PAGE_SIZE;
2011 		}
2012 
2013 		if (page_has_buffers(tmppage)) {
2014 			if (handle && ocfs2_should_order_data(inode)) {
2015 				loff_t start_byte =
2016 					((loff_t)tmppage->index << PAGE_SHIFT) +
2017 					from;
2018 				loff_t length = to - from;
2019 				ocfs2_jbd2_inode_add_write(handle, inode,
2020 							   start_byte, length);
2021 			}
2022 			block_commit_write(tmppage, from, to);
2023 		}
2024 	}
2025 
2026 out_write_size:
2027 	/* Direct io do not update i_size here. */
2028 	if (wc->w_type != OCFS2_WRITE_DIRECT) {
2029 		pos += copied;
2030 		if (pos > i_size_read(inode)) {
2031 			i_size_write(inode, pos);
2032 			mark_inode_dirty(inode);
2033 		}
2034 		inode->i_blocks = ocfs2_inode_sector_count(inode);
2035 		di->i_size = cpu_to_le64((u64)i_size_read(inode));
2036 		inode->i_mtime = inode->i_ctime = current_time(inode);
2037 		di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
2038 		di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
2039 		if (handle)
2040 			ocfs2_update_inode_fsync_trans(handle, inode, 1);
2041 	}
2042 	if (handle)
2043 		ocfs2_journal_dirty(handle, wc->w_di_bh);
2044 
2045 out:
2046 	/* unlock pages before dealloc since it needs acquiring j_trans_barrier
2047 	 * lock, or it will cause a deadlock since journal commit threads holds
2048 	 * this lock and will ask for the page lock when flushing the data.
2049 	 * put it here to preserve the unlock order.
2050 	 */
2051 	ocfs2_unlock_pages(wc);
2052 
2053 	if (handle)
2054 		ocfs2_commit_trans(osb, handle);
2055 
2056 	ocfs2_run_deallocs(osb, &wc->w_dealloc);
2057 
2058 	brelse(wc->w_di_bh);
2059 	kfree(wc);
2060 
2061 	return copied;
2062 }
2063 
ocfs2_write_end(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct page * page,void * fsdata)2064 static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2065 			   loff_t pos, unsigned len, unsigned copied,
2066 			   struct page *page, void *fsdata)
2067 {
2068 	int ret;
2069 	struct inode *inode = mapping->host;
2070 
2071 	ret = ocfs2_write_end_nolock(mapping, pos, len, copied, fsdata);
2072 
2073 	up_write(&OCFS2_I(inode)->ip_alloc_sem);
2074 	ocfs2_inode_unlock(inode, 1);
2075 
2076 	return ret;
2077 }
2078 
2079 struct ocfs2_dio_write_ctxt {
2080 	struct list_head	dw_zero_list;
2081 	unsigned		dw_zero_count;
2082 	int			dw_orphaned;
2083 	pid_t			dw_writer_pid;
2084 };
2085 
2086 static struct ocfs2_dio_write_ctxt *
ocfs2_dio_alloc_write_ctx(struct buffer_head * bh,int * alloc)2087 ocfs2_dio_alloc_write_ctx(struct buffer_head *bh, int *alloc)
2088 {
2089 	struct ocfs2_dio_write_ctxt *dwc = NULL;
2090 
2091 	if (bh->b_private)
2092 		return bh->b_private;
2093 
2094 	dwc = kmalloc(sizeof(struct ocfs2_dio_write_ctxt), GFP_NOFS);
2095 	if (dwc == NULL)
2096 		return NULL;
2097 	INIT_LIST_HEAD(&dwc->dw_zero_list);
2098 	dwc->dw_zero_count = 0;
2099 	dwc->dw_orphaned = 0;
2100 	dwc->dw_writer_pid = task_pid_nr(current);
2101 	bh->b_private = dwc;
2102 	*alloc = 1;
2103 
2104 	return dwc;
2105 }
2106 
ocfs2_dio_free_write_ctx(struct inode * inode,struct ocfs2_dio_write_ctxt * dwc)2107 static void ocfs2_dio_free_write_ctx(struct inode *inode,
2108 				     struct ocfs2_dio_write_ctxt *dwc)
2109 {
2110 	ocfs2_free_unwritten_list(inode, &dwc->dw_zero_list);
2111 	kfree(dwc);
2112 }
2113 
2114 /*
2115  * TODO: Make this into a generic get_blocks function.
2116  *
2117  * From do_direct_io in direct-io.c:
2118  *  "So what we do is to permit the ->get_blocks function to populate
2119  *   bh.b_size with the size of IO which is permitted at this offset and
2120  *   this i_blkbits."
2121  *
2122  * This function is called directly from get_more_blocks in direct-io.c.
2123  *
2124  * called like this: dio->get_blocks(dio->inode, fs_startblk,
2125  * 					fs_count, map_bh, dio->rw == WRITE);
2126  */
ocfs2_dio_wr_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)2127 static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock,
2128 			       struct buffer_head *bh_result, int create)
2129 {
2130 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2131 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2132 	struct ocfs2_write_ctxt *wc;
2133 	struct ocfs2_write_cluster_desc *desc = NULL;
2134 	struct ocfs2_dio_write_ctxt *dwc = NULL;
2135 	struct buffer_head *di_bh = NULL;
2136 	u64 p_blkno;
2137 	unsigned int i_blkbits = inode->i_sb->s_blocksize_bits;
2138 	loff_t pos = iblock << i_blkbits;
2139 	sector_t endblk = (i_size_read(inode) - 1) >> i_blkbits;
2140 	unsigned len, total_len = bh_result->b_size;
2141 	int ret = 0, first_get_block = 0;
2142 
2143 	len = osb->s_clustersize - (pos & (osb->s_clustersize - 1));
2144 	len = min(total_len, len);
2145 
2146 	/*
2147 	 * bh_result->b_size is count in get_more_blocks according to write
2148 	 * "pos" and "end", we need map twice to return different buffer state:
2149 	 * 1. area in file size, not set NEW;
2150 	 * 2. area out file size, set  NEW.
2151 	 *
2152 	 *		   iblock    endblk
2153 	 * |--------|---------|---------|---------
2154 	 * |<-------area in file------->|
2155 	 */
2156 
2157 	if ((iblock <= endblk) &&
2158 	    ((iblock + ((len - 1) >> i_blkbits)) > endblk))
2159 		len = (endblk - iblock + 1) << i_blkbits;
2160 
2161 	mlog(0, "get block of %lu at %llu:%u req %u\n",
2162 			inode->i_ino, pos, len, total_len);
2163 
2164 	/*
2165 	 * Because we need to change file size in ocfs2_dio_end_io_write(), or
2166 	 * we may need to add it to orphan dir. So can not fall to fast path
2167 	 * while file size will be changed.
2168 	 */
2169 	if (pos + total_len <= i_size_read(inode)) {
2170 
2171 		/* This is the fast path for re-write. */
2172 		ret = ocfs2_lock_get_block(inode, iblock, bh_result, create);
2173 		if (buffer_mapped(bh_result) &&
2174 		    !buffer_new(bh_result) &&
2175 		    ret == 0)
2176 			goto out;
2177 
2178 		/* Clear state set by ocfs2_get_block. */
2179 		bh_result->b_state = 0;
2180 	}
2181 
2182 	dwc = ocfs2_dio_alloc_write_ctx(bh_result, &first_get_block);
2183 	if (unlikely(dwc == NULL)) {
2184 		ret = -ENOMEM;
2185 		mlog_errno(ret);
2186 		goto out;
2187 	}
2188 
2189 	if (ocfs2_clusters_for_bytes(inode->i_sb, pos + total_len) >
2190 	    ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode)) &&
2191 	    !dwc->dw_orphaned) {
2192 		/*
2193 		 * when we are going to alloc extents beyond file size, add the
2194 		 * inode to orphan dir, so we can recall those spaces when
2195 		 * system crashed during write.
2196 		 */
2197 		ret = ocfs2_add_inode_to_orphan(osb, inode);
2198 		if (ret < 0) {
2199 			mlog_errno(ret);
2200 			goto out;
2201 		}
2202 		dwc->dw_orphaned = 1;
2203 	}
2204 
2205 	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2206 	if (ret) {
2207 		mlog_errno(ret);
2208 		goto out;
2209 	}
2210 
2211 	down_write(&oi->ip_alloc_sem);
2212 
2213 	if (first_get_block) {
2214 		if (ocfs2_sparse_alloc(osb))
2215 			ret = ocfs2_zero_tail(inode, di_bh, pos);
2216 		else
2217 			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
2218 							   total_len, NULL);
2219 		if (ret < 0) {
2220 			mlog_errno(ret);
2221 			goto unlock;
2222 		}
2223 	}
2224 
2225 	ret = ocfs2_write_begin_nolock(inode->i_mapping, pos, len,
2226 				       OCFS2_WRITE_DIRECT, NULL,
2227 				       (void **)&wc, di_bh, NULL);
2228 	if (ret) {
2229 		mlog_errno(ret);
2230 		goto unlock;
2231 	}
2232 
2233 	desc = &wc->w_desc[0];
2234 
2235 	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, desc->c_phys);
2236 	BUG_ON(p_blkno == 0);
2237 	p_blkno += iblock & (u64)(ocfs2_clusters_to_blocks(inode->i_sb, 1) - 1);
2238 
2239 	map_bh(bh_result, inode->i_sb, p_blkno);
2240 	bh_result->b_size = len;
2241 	if (desc->c_needs_zero)
2242 		set_buffer_new(bh_result);
2243 
2244 	if (iblock > endblk)
2245 		set_buffer_new(bh_result);
2246 
2247 	/* May sleep in end_io. It should not happen in a irq context. So defer
2248 	 * it to dio work queue. */
2249 	set_buffer_defer_completion(bh_result);
2250 
2251 	if (!list_empty(&wc->w_unwritten_list)) {
2252 		struct ocfs2_unwritten_extent *ue = NULL;
2253 
2254 		ue = list_first_entry(&wc->w_unwritten_list,
2255 				      struct ocfs2_unwritten_extent,
2256 				      ue_node);
2257 		BUG_ON(ue->ue_cpos != desc->c_cpos);
2258 		/* The physical address may be 0, fill it. */
2259 		ue->ue_phys = desc->c_phys;
2260 
2261 		list_splice_tail_init(&wc->w_unwritten_list, &dwc->dw_zero_list);
2262 		dwc->dw_zero_count += wc->w_unwritten_count;
2263 	}
2264 
2265 	ret = ocfs2_write_end_nolock(inode->i_mapping, pos, len, len, wc);
2266 	BUG_ON(ret != len);
2267 	ret = 0;
2268 unlock:
2269 	up_write(&oi->ip_alloc_sem);
2270 	ocfs2_inode_unlock(inode, 1);
2271 	brelse(di_bh);
2272 out:
2273 	if (ret < 0)
2274 		ret = -EIO;
2275 	return ret;
2276 }
2277 
ocfs2_dio_end_io_write(struct inode * inode,struct ocfs2_dio_write_ctxt * dwc,loff_t offset,ssize_t bytes)2278 static int ocfs2_dio_end_io_write(struct inode *inode,
2279 				  struct ocfs2_dio_write_ctxt *dwc,
2280 				  loff_t offset,
2281 				  ssize_t bytes)
2282 {
2283 	struct ocfs2_cached_dealloc_ctxt dealloc;
2284 	struct ocfs2_extent_tree et;
2285 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2286 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2287 	struct ocfs2_unwritten_extent *ue = NULL;
2288 	struct buffer_head *di_bh = NULL;
2289 	struct ocfs2_dinode *di;
2290 	struct ocfs2_alloc_context *data_ac = NULL;
2291 	struct ocfs2_alloc_context *meta_ac = NULL;
2292 	handle_t *handle = NULL;
2293 	loff_t end = offset + bytes;
2294 	int ret = 0, credits = 0;
2295 
2296 	ocfs2_init_dealloc_ctxt(&dealloc);
2297 
2298 	/* We do clear unwritten, delete orphan, change i_size here. If neither
2299 	 * of these happen, we can skip all this. */
2300 	if (list_empty(&dwc->dw_zero_list) &&
2301 	    end <= i_size_read(inode) &&
2302 	    !dwc->dw_orphaned)
2303 		goto out;
2304 
2305 	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2306 	if (ret < 0) {
2307 		mlog_errno(ret);
2308 		goto out;
2309 	}
2310 
2311 	down_write(&oi->ip_alloc_sem);
2312 
2313 	/* Delete orphan before acquire i_rwsem. */
2314 	if (dwc->dw_orphaned) {
2315 		BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
2316 
2317 		end = end > i_size_read(inode) ? end : 0;
2318 
2319 		ret = ocfs2_del_inode_from_orphan(osb, inode, di_bh,
2320 				!!end, end);
2321 		if (ret < 0)
2322 			mlog_errno(ret);
2323 	}
2324 
2325 	di = (struct ocfs2_dinode *)di_bh->b_data;
2326 
2327 	ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
2328 
2329 	/* Attach dealloc with extent tree in case that we may reuse extents
2330 	 * which are already unlinked from current extent tree due to extent
2331 	 * rotation and merging.
2332 	 */
2333 	et.et_dealloc = &dealloc;
2334 
2335 	ret = ocfs2_lock_allocators(inode, &et, 0, dwc->dw_zero_count*2,
2336 				    &data_ac, &meta_ac);
2337 	if (ret) {
2338 		mlog_errno(ret);
2339 		goto unlock;
2340 	}
2341 
2342 	credits = ocfs2_calc_extend_credits(inode->i_sb, &di->id2.i_list);
2343 
2344 	handle = ocfs2_start_trans(osb, credits);
2345 	if (IS_ERR(handle)) {
2346 		ret = PTR_ERR(handle);
2347 		mlog_errno(ret);
2348 		goto unlock;
2349 	}
2350 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
2351 				      OCFS2_JOURNAL_ACCESS_WRITE);
2352 	if (ret) {
2353 		mlog_errno(ret);
2354 		goto commit;
2355 	}
2356 
2357 	list_for_each_entry(ue, &dwc->dw_zero_list, ue_node) {
2358 		ret = ocfs2_mark_extent_written(inode, &et, handle,
2359 						ue->ue_cpos, 1,
2360 						ue->ue_phys,
2361 						meta_ac, &dealloc);
2362 		if (ret < 0) {
2363 			mlog_errno(ret);
2364 			break;
2365 		}
2366 	}
2367 
2368 	if (end > i_size_read(inode)) {
2369 		ret = ocfs2_set_inode_size(handle, inode, di_bh, end);
2370 		if (ret < 0)
2371 			mlog_errno(ret);
2372 	}
2373 commit:
2374 	ocfs2_commit_trans(osb, handle);
2375 unlock:
2376 	up_write(&oi->ip_alloc_sem);
2377 	ocfs2_inode_unlock(inode, 1);
2378 	brelse(di_bh);
2379 out:
2380 	if (data_ac)
2381 		ocfs2_free_alloc_context(data_ac);
2382 	if (meta_ac)
2383 		ocfs2_free_alloc_context(meta_ac);
2384 	ocfs2_run_deallocs(osb, &dealloc);
2385 	ocfs2_dio_free_write_ctx(inode, dwc);
2386 
2387 	return ret;
2388 }
2389 
2390 /*
2391  * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
2392  * particularly interested in the aio/dio case.  We use the rw_lock DLM lock
2393  * to protect io on one node from truncation on another.
2394  */
ocfs2_dio_end_io(struct kiocb * iocb,loff_t offset,ssize_t bytes,void * private)2395 static int ocfs2_dio_end_io(struct kiocb *iocb,
2396 			    loff_t offset,
2397 			    ssize_t bytes,
2398 			    void *private)
2399 {
2400 	struct inode *inode = file_inode(iocb->ki_filp);
2401 	int level;
2402 	int ret = 0;
2403 
2404 	/* this io's submitter should not have unlocked this before we could */
2405 	BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
2406 
2407 	if (bytes <= 0)
2408 		mlog_ratelimited(ML_ERROR, "Direct IO failed, bytes = %lld",
2409 				 (long long)bytes);
2410 	if (private) {
2411 		if (bytes > 0)
2412 			ret = ocfs2_dio_end_io_write(inode, private, offset,
2413 						     bytes);
2414 		else
2415 			ocfs2_dio_free_write_ctx(inode, private);
2416 	}
2417 
2418 	ocfs2_iocb_clear_rw_locked(iocb);
2419 
2420 	level = ocfs2_iocb_rw_locked_level(iocb);
2421 	ocfs2_rw_unlock(inode, level);
2422 	return ret;
2423 }
2424 
ocfs2_direct_IO(struct kiocb * iocb,struct iov_iter * iter)2425 static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
2426 {
2427 	struct file *file = iocb->ki_filp;
2428 	struct inode *inode = file->f_mapping->host;
2429 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2430 	get_block_t *get_block;
2431 
2432 	/*
2433 	 * Fallback to buffered I/O if we see an inode without
2434 	 * extents.
2435 	 */
2436 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
2437 		return 0;
2438 
2439 	/* Fallback to buffered I/O if we do not support append dio. */
2440 	if (iocb->ki_pos + iter->count > i_size_read(inode) &&
2441 	    !ocfs2_supports_append_dio(osb))
2442 		return 0;
2443 
2444 	if (iov_iter_rw(iter) == READ)
2445 		get_block = ocfs2_lock_get_block;
2446 	else
2447 		get_block = ocfs2_dio_wr_get_block;
2448 
2449 	return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
2450 				    iter, get_block,
2451 				    ocfs2_dio_end_io, NULL, 0);
2452 }
2453 
2454 const struct address_space_operations ocfs2_aops = {
2455 	.dirty_folio		= block_dirty_folio,
2456 	.read_folio		= ocfs2_read_folio,
2457 	.readahead		= ocfs2_readahead,
2458 	.writepage		= ocfs2_writepage,
2459 	.write_begin		= ocfs2_write_begin,
2460 	.write_end		= ocfs2_write_end,
2461 	.bmap			= ocfs2_bmap,
2462 	.direct_IO		= ocfs2_direct_IO,
2463 	.invalidate_folio	= block_invalidate_folio,
2464 	.release_folio		= ocfs2_release_folio,
2465 	.migrate_folio		= buffer_migrate_folio,
2466 	.is_partially_uptodate	= block_is_partially_uptodate,
2467 	.error_remove_page	= generic_error_remove_page,
2468 };
2469