1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public
17  * License along with this program; if not, write to the
18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19  * Boston, MA 021110-1307, USA.
20  */
21 
22 #include <linux/fs.h>
23 #include <linux/slab.h>
24 #include <linux/highmem.h>
25 #include <linux/pagemap.h>
26 #include <asm/byteorder.h>
27 #include <linux/swap.h>
28 #include <linux/pipe_fs_i.h>
29 #include <linux/mpage.h>
30 #include <linux/quotaops.h>
31 #include <linux/blkdev.h>
32 #include <linux/uio.h>
33 
34 #include <cluster/masklog.h>
35 
36 #include "ocfs2.h"
37 
38 #include "alloc.h"
39 #include "aops.h"
40 #include "dlmglue.h"
41 #include "extent_map.h"
42 #include "file.h"
43 #include "inode.h"
44 #include "journal.h"
45 #include "suballoc.h"
46 #include "super.h"
47 #include "symlink.h"
48 #include "refcounttree.h"
49 #include "ocfs2_trace.h"
50 
51 #include "buffer_head_io.h"
52 #include "dir.h"
53 #include "namei.h"
54 #include "sysfile.h"
55 
ocfs2_symlink_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)56 static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
57 				   struct buffer_head *bh_result, int create)
58 {
59 	int err = -EIO;
60 	int status;
61 	struct ocfs2_dinode *fe = NULL;
62 	struct buffer_head *bh = NULL;
63 	struct buffer_head *buffer_cache_bh = NULL;
64 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
65 	void *kaddr;
66 
67 	trace_ocfs2_symlink_get_block(
68 			(unsigned long long)OCFS2_I(inode)->ip_blkno,
69 			(unsigned long long)iblock, bh_result, create);
70 
71 	BUG_ON(ocfs2_inode_is_fast_symlink(inode));
72 
73 	if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
74 		mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
75 		     (unsigned long long)iblock);
76 		goto bail;
77 	}
78 
79 	status = ocfs2_read_inode_block(inode, &bh);
80 	if (status < 0) {
81 		mlog_errno(status);
82 		goto bail;
83 	}
84 	fe = (struct ocfs2_dinode *) bh->b_data;
85 
86 	if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
87 						    le32_to_cpu(fe->i_clusters))) {
88 		err = -ENOMEM;
89 		mlog(ML_ERROR, "block offset is outside the allocated size: "
90 		     "%llu\n", (unsigned long long)iblock);
91 		goto bail;
92 	}
93 
94 	/* We don't use the page cache to create symlink data, so if
95 	 * need be, copy it over from the buffer cache. */
96 	if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
97 		u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
98 			    iblock;
99 		buffer_cache_bh = sb_getblk(osb->sb, blkno);
100 		if (!buffer_cache_bh) {
101 			err = -ENOMEM;
102 			mlog(ML_ERROR, "couldn't getblock for symlink!\n");
103 			goto bail;
104 		}
105 
106 		/* we haven't locked out transactions, so a commit
107 		 * could've happened. Since we've got a reference on
108 		 * the bh, even if it commits while we're doing the
109 		 * copy, the data is still good. */
110 		if (buffer_jbd(buffer_cache_bh)
111 		    && ocfs2_inode_is_new(inode)) {
112 			kaddr = kmap_atomic(bh_result->b_page);
113 			if (!kaddr) {
114 				mlog(ML_ERROR, "couldn't kmap!\n");
115 				goto bail;
116 			}
117 			memcpy(kaddr + (bh_result->b_size * iblock),
118 			       buffer_cache_bh->b_data,
119 			       bh_result->b_size);
120 			kunmap_atomic(kaddr);
121 			set_buffer_uptodate(bh_result);
122 		}
123 		brelse(buffer_cache_bh);
124 	}
125 
126 	map_bh(bh_result, inode->i_sb,
127 	       le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
128 
129 	err = 0;
130 
131 bail:
132 	brelse(bh);
133 
134 	return err;
135 }
136 
ocfs2_lock_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)137 static int ocfs2_lock_get_block(struct inode *inode, sector_t iblock,
138 		    struct buffer_head *bh_result, int create)
139 {
140 	int ret = 0;
141 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
142 
143 	down_read(&oi->ip_alloc_sem);
144 	ret = ocfs2_get_block(inode, iblock, bh_result, create);
145 	up_read(&oi->ip_alloc_sem);
146 
147 	return ret;
148 }
149 
ocfs2_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)150 int ocfs2_get_block(struct inode *inode, sector_t iblock,
151 		    struct buffer_head *bh_result, int create)
152 {
153 	int err = 0;
154 	unsigned int ext_flags;
155 	u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
156 	u64 p_blkno, count, past_eof;
157 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
158 
159 	trace_ocfs2_get_block((unsigned long long)OCFS2_I(inode)->ip_blkno,
160 			      (unsigned long long)iblock, bh_result, create);
161 
162 	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
163 		mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
164 		     inode, inode->i_ino);
165 
166 	if (S_ISLNK(inode->i_mode)) {
167 		/* this always does I/O for some reason. */
168 		err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
169 		goto bail;
170 	}
171 
172 	err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
173 					  &ext_flags);
174 	if (err) {
175 		mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
176 		     "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
177 		     (unsigned long long)p_blkno);
178 		goto bail;
179 	}
180 
181 	if (max_blocks < count)
182 		count = max_blocks;
183 
184 	/*
185 	 * ocfs2 never allocates in this function - the only time we
186 	 * need to use BH_New is when we're extending i_size on a file
187 	 * system which doesn't support holes, in which case BH_New
188 	 * allows __block_write_begin() to zero.
189 	 *
190 	 * If we see this on a sparse file system, then a truncate has
191 	 * raced us and removed the cluster. In this case, we clear
192 	 * the buffers dirty and uptodate bits and let the buffer code
193 	 * ignore it as a hole.
194 	 */
195 	if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
196 		clear_buffer_dirty(bh_result);
197 		clear_buffer_uptodate(bh_result);
198 		goto bail;
199 	}
200 
201 	/* Treat the unwritten extent as a hole for zeroing purposes. */
202 	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
203 		map_bh(bh_result, inode->i_sb, p_blkno);
204 
205 	bh_result->b_size = count << inode->i_blkbits;
206 
207 	if (!ocfs2_sparse_alloc(osb)) {
208 		if (p_blkno == 0) {
209 			err = -EIO;
210 			mlog(ML_ERROR,
211 			     "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
212 			     (unsigned long long)iblock,
213 			     (unsigned long long)p_blkno,
214 			     (unsigned long long)OCFS2_I(inode)->ip_blkno);
215 			mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
216 			dump_stack();
217 			goto bail;
218 		}
219 	}
220 
221 	past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
222 
223 	trace_ocfs2_get_block_end((unsigned long long)OCFS2_I(inode)->ip_blkno,
224 				  (unsigned long long)past_eof);
225 	if (create && (iblock >= past_eof))
226 		set_buffer_new(bh_result);
227 
228 bail:
229 	if (err < 0)
230 		err = -EIO;
231 
232 	return err;
233 }
234 
ocfs2_read_inline_data(struct inode * inode,struct page * page,struct buffer_head * di_bh)235 int ocfs2_read_inline_data(struct inode *inode, struct page *page,
236 			   struct buffer_head *di_bh)
237 {
238 	void *kaddr;
239 	loff_t size;
240 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
241 
242 	if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
243 		ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag\n",
244 			    (unsigned long long)OCFS2_I(inode)->ip_blkno);
245 		return -EROFS;
246 	}
247 
248 	size = i_size_read(inode);
249 
250 	if (size > PAGE_SIZE ||
251 	    size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
252 		ocfs2_error(inode->i_sb,
253 			    "Inode %llu has with inline data has bad size: %Lu\n",
254 			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
255 			    (unsigned long long)size);
256 		return -EROFS;
257 	}
258 
259 	kaddr = kmap_atomic(page);
260 	if (size)
261 		memcpy(kaddr, di->id2.i_data.id_data, size);
262 	/* Clear the remaining part of the page */
263 	memset(kaddr + size, 0, PAGE_SIZE - size);
264 	flush_dcache_page(page);
265 	kunmap_atomic(kaddr);
266 
267 	SetPageUptodate(page);
268 
269 	return 0;
270 }
271 
ocfs2_readpage_inline(struct inode * inode,struct page * page)272 static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
273 {
274 	int ret;
275 	struct buffer_head *di_bh = NULL;
276 
277 	BUG_ON(!PageLocked(page));
278 	BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
279 
280 	ret = ocfs2_read_inode_block(inode, &di_bh);
281 	if (ret) {
282 		mlog_errno(ret);
283 		goto out;
284 	}
285 
286 	ret = ocfs2_read_inline_data(inode, page, di_bh);
287 out:
288 	unlock_page(page);
289 
290 	brelse(di_bh);
291 	return ret;
292 }
293 
ocfs2_readpage(struct file * file,struct page * page)294 static int ocfs2_readpage(struct file *file, struct page *page)
295 {
296 	struct inode *inode = page->mapping->host;
297 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
298 	loff_t start = (loff_t)page->index << PAGE_SHIFT;
299 	int ret, unlock = 1;
300 
301 	trace_ocfs2_readpage((unsigned long long)oi->ip_blkno,
302 			     (page ? page->index : 0));
303 
304 	ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
305 	if (ret != 0) {
306 		if (ret == AOP_TRUNCATED_PAGE)
307 			unlock = 0;
308 		mlog_errno(ret);
309 		goto out;
310 	}
311 
312 	if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
313 		/*
314 		 * Unlock the page and cycle ip_alloc_sem so that we don't
315 		 * busyloop waiting for ip_alloc_sem to unlock
316 		 */
317 		ret = AOP_TRUNCATED_PAGE;
318 		unlock_page(page);
319 		unlock = 0;
320 		down_read(&oi->ip_alloc_sem);
321 		up_read(&oi->ip_alloc_sem);
322 		goto out_inode_unlock;
323 	}
324 
325 	/*
326 	 * i_size might have just been updated as we grabed the meta lock.  We
327 	 * might now be discovering a truncate that hit on another node.
328 	 * block_read_full_page->get_block freaks out if it is asked to read
329 	 * beyond the end of a file, so we check here.  Callers
330 	 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
331 	 * and notice that the page they just read isn't needed.
332 	 *
333 	 * XXX sys_readahead() seems to get that wrong?
334 	 */
335 	if (start >= i_size_read(inode)) {
336 		zero_user(page, 0, PAGE_SIZE);
337 		SetPageUptodate(page);
338 		ret = 0;
339 		goto out_alloc;
340 	}
341 
342 	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
343 		ret = ocfs2_readpage_inline(inode, page);
344 	else
345 		ret = block_read_full_page(page, ocfs2_get_block);
346 	unlock = 0;
347 
348 out_alloc:
349 	up_read(&oi->ip_alloc_sem);
350 out_inode_unlock:
351 	ocfs2_inode_unlock(inode, 0);
352 out:
353 	if (unlock)
354 		unlock_page(page);
355 	return ret;
356 }
357 
358 /*
359  * This is used only for read-ahead. Failures or difficult to handle
360  * situations are safe to ignore.
361  *
362  * Right now, we don't bother with BH_Boundary - in-inode extent lists
363  * are quite large (243 extents on 4k blocks), so most inodes don't
364  * grow out to a tree. If need be, detecting boundary extents could
365  * trivially be added in a future version of ocfs2_get_block().
366  */
ocfs2_readpages(struct file * filp,struct address_space * mapping,struct list_head * pages,unsigned nr_pages)367 static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
368 			   struct list_head *pages, unsigned nr_pages)
369 {
370 	int ret, err = -EIO;
371 	struct inode *inode = mapping->host;
372 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
373 	loff_t start;
374 	struct page *last;
375 
376 	/*
377 	 * Use the nonblocking flag for the dlm code to avoid page
378 	 * lock inversion, but don't bother with retrying.
379 	 */
380 	ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
381 	if (ret)
382 		return err;
383 
384 	if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
385 		ocfs2_inode_unlock(inode, 0);
386 		return err;
387 	}
388 
389 	/*
390 	 * Don't bother with inline-data. There isn't anything
391 	 * to read-ahead in that case anyway...
392 	 */
393 	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
394 		goto out_unlock;
395 
396 	/*
397 	 * Check whether a remote node truncated this file - we just
398 	 * drop out in that case as it's not worth handling here.
399 	 */
400 	last = list_entry(pages->prev, struct page, lru);
401 	start = (loff_t)last->index << PAGE_SHIFT;
402 	if (start >= i_size_read(inode))
403 		goto out_unlock;
404 
405 	err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
406 
407 out_unlock:
408 	up_read(&oi->ip_alloc_sem);
409 	ocfs2_inode_unlock(inode, 0);
410 
411 	return err;
412 }
413 
414 /* Note: Because we don't support holes, our allocation has
415  * already happened (allocation writes zeros to the file data)
416  * so we don't have to worry about ordered writes in
417  * ocfs2_writepage.
418  *
419  * ->writepage is called during the process of invalidating the page cache
420  * during blocked lock processing.  It can't block on any cluster locks
421  * to during block mapping.  It's relying on the fact that the block
422  * mapping can't have disappeared under the dirty pages that it is
423  * being asked to write back.
424  */
ocfs2_writepage(struct page * page,struct writeback_control * wbc)425 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
426 {
427 	trace_ocfs2_writepage(
428 		(unsigned long long)OCFS2_I(page->mapping->host)->ip_blkno,
429 		page->index);
430 
431 	return block_write_full_page(page, ocfs2_get_block, wbc);
432 }
433 
434 /* Taken from ext3. We don't necessarily need the full blown
435  * functionality yet, but IMHO it's better to cut and paste the whole
436  * thing so we can avoid introducing our own bugs (and easily pick up
437  * 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))438 int walk_page_buffers(	handle_t *handle,
439 			struct buffer_head *head,
440 			unsigned from,
441 			unsigned to,
442 			int *partial,
443 			int (*fn)(	handle_t *handle,
444 					struct buffer_head *bh))
445 {
446 	struct buffer_head *bh;
447 	unsigned block_start, block_end;
448 	unsigned blocksize = head->b_size;
449 	int err, ret = 0;
450 	struct buffer_head *next;
451 
452 	for (	bh = head, block_start = 0;
453 		ret == 0 && (bh != head || !block_start);
454 	    	block_start = block_end, bh = next)
455 	{
456 		next = bh->b_this_page;
457 		block_end = block_start + blocksize;
458 		if (block_end <= from || block_start >= to) {
459 			if (partial && !buffer_uptodate(bh))
460 				*partial = 1;
461 			continue;
462 		}
463 		err = (*fn)(handle, bh);
464 		if (!ret)
465 			ret = err;
466 	}
467 	return ret;
468 }
469 
ocfs2_bmap(struct address_space * mapping,sector_t block)470 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
471 {
472 	sector_t status;
473 	u64 p_blkno = 0;
474 	int err = 0;
475 	struct inode *inode = mapping->host;
476 
477 	trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno,
478 			 (unsigned long long)block);
479 
480 	/*
481 	 * The swap code (ab-)uses ->bmap to get a block mapping and then
482 	 * bypasseѕ the file system for actual I/O.  We really can't allow
483 	 * that on refcounted inodes, so we have to skip out here.  And yes,
484 	 * 0 is the magic code for a bmap error..
485 	 */
486 	if (ocfs2_is_refcount_inode(inode))
487 		return 0;
488 
489 	/* We don't need to lock journal system files, since they aren't
490 	 * accessed concurrently from multiple nodes.
491 	 */
492 	if (!INODE_JOURNAL(inode)) {
493 		err = ocfs2_inode_lock(inode, NULL, 0);
494 		if (err) {
495 			if (err != -ENOENT)
496 				mlog_errno(err);
497 			goto bail;
498 		}
499 		down_read(&OCFS2_I(inode)->ip_alloc_sem);
500 	}
501 
502 	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
503 		err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
504 						  NULL);
505 
506 	if (!INODE_JOURNAL(inode)) {
507 		up_read(&OCFS2_I(inode)->ip_alloc_sem);
508 		ocfs2_inode_unlock(inode, 0);
509 	}
510 
511 	if (err) {
512 		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
513 		     (unsigned long long)block);
514 		mlog_errno(err);
515 		goto bail;
516 	}
517 
518 bail:
519 	status = err ? 0 : p_blkno;
520 
521 	return status;
522 }
523 
ocfs2_releasepage(struct page * page,gfp_t wait)524 static int ocfs2_releasepage(struct page *page, gfp_t wait)
525 {
526 	if (!page_has_buffers(page))
527 		return 0;
528 	return try_to_free_buffers(page);
529 }
530 
ocfs2_figure_cluster_boundaries(struct ocfs2_super * osb,u32 cpos,unsigned int * start,unsigned int * end)531 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
532 					    u32 cpos,
533 					    unsigned int *start,
534 					    unsigned int *end)
535 {
536 	unsigned int cluster_start = 0, cluster_end = PAGE_SIZE;
537 
538 	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits)) {
539 		unsigned int cpp;
540 
541 		cpp = 1 << (PAGE_SHIFT - osb->s_clustersize_bits);
542 
543 		cluster_start = cpos % cpp;
544 		cluster_start = cluster_start << osb->s_clustersize_bits;
545 
546 		cluster_end = cluster_start + osb->s_clustersize;
547 	}
548 
549 	BUG_ON(cluster_start > PAGE_SIZE);
550 	BUG_ON(cluster_end > PAGE_SIZE);
551 
552 	if (start)
553 		*start = cluster_start;
554 	if (end)
555 		*end = cluster_end;
556 }
557 
558 /*
559  * 'from' and 'to' are the region in the page to avoid zeroing.
560  *
561  * If pagesize > clustersize, this function will avoid zeroing outside
562  * of the cluster boundary.
563  *
564  * from == to == 0 is code for "zero the entire cluster region"
565  */
ocfs2_clear_page_regions(struct page * page,struct ocfs2_super * osb,u32 cpos,unsigned from,unsigned to)566 static void ocfs2_clear_page_regions(struct page *page,
567 				     struct ocfs2_super *osb, u32 cpos,
568 				     unsigned from, unsigned to)
569 {
570 	void *kaddr;
571 	unsigned int cluster_start, cluster_end;
572 
573 	ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
574 
575 	kaddr = kmap_atomic(page);
576 
577 	if (from || to) {
578 		if (from > cluster_start)
579 			memset(kaddr + cluster_start, 0, from - cluster_start);
580 		if (to < cluster_end)
581 			memset(kaddr + to, 0, cluster_end - to);
582 	} else {
583 		memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
584 	}
585 
586 	kunmap_atomic(kaddr);
587 }
588 
589 /*
590  * Nonsparse file systems fully allocate before we get to the write
591  * code. This prevents ocfs2_write() from tagging the write as an
592  * allocating one, which means ocfs2_map_page_blocks() might try to
593  * read-in the blocks at the tail of our file. Avoid reading them by
594  * testing i_size against each block offset.
595  */
ocfs2_should_read_blk(struct inode * inode,struct page * page,unsigned int block_start)596 static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
597 				 unsigned int block_start)
598 {
599 	u64 offset = page_offset(page) + block_start;
600 
601 	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
602 		return 1;
603 
604 	if (i_size_read(inode) > offset)
605 		return 1;
606 
607 	return 0;
608 }
609 
610 /*
611  * Some of this taken from __block_write_begin(). We already have our
612  * mapping by now though, and the entire write will be allocating or
613  * it won't, so not much need to use BH_New.
614  *
615  * This will also skip zeroing, which is handled externally.
616  */
ocfs2_map_page_blocks(struct page * page,u64 * p_blkno,struct inode * inode,unsigned int from,unsigned int to,int new)617 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
618 			  struct inode *inode, unsigned int from,
619 			  unsigned int to, int new)
620 {
621 	int ret = 0;
622 	struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
623 	unsigned int block_end, block_start;
624 	unsigned int bsize = i_blocksize(inode);
625 
626 	if (!page_has_buffers(page))
627 		create_empty_buffers(page, bsize, 0);
628 
629 	head = page_buffers(page);
630 	for (bh = head, block_start = 0; bh != head || !block_start;
631 	     bh = bh->b_this_page, block_start += bsize) {
632 		block_end = block_start + bsize;
633 
634 		clear_buffer_new(bh);
635 
636 		/*
637 		 * Ignore blocks outside of our i/o range -
638 		 * they may belong to unallocated clusters.
639 		 */
640 		if (block_start >= to || block_end <= from) {
641 			if (PageUptodate(page))
642 				set_buffer_uptodate(bh);
643 			continue;
644 		}
645 
646 		/*
647 		 * For an allocating write with cluster size >= page
648 		 * size, we always write the entire page.
649 		 */
650 		if (new)
651 			set_buffer_new(bh);
652 
653 		if (!buffer_mapped(bh)) {
654 			map_bh(bh, inode->i_sb, *p_blkno);
655 			clean_bdev_bh_alias(bh);
656 		}
657 
658 		if (PageUptodate(page)) {
659 			if (!buffer_uptodate(bh))
660 				set_buffer_uptodate(bh);
661 		} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
662 			   !buffer_new(bh) &&
663 			   ocfs2_should_read_blk(inode, page, block_start) &&
664 			   (block_start < from || block_end > to)) {
665 			ll_rw_block(REQ_OP_READ, 0, 1, &bh);
666 			*wait_bh++=bh;
667 		}
668 
669 		*p_blkno = *p_blkno + 1;
670 	}
671 
672 	/*
673 	 * If we issued read requests - let them complete.
674 	 */
675 	while(wait_bh > wait) {
676 		wait_on_buffer(*--wait_bh);
677 		if (!buffer_uptodate(*wait_bh))
678 			ret = -EIO;
679 	}
680 
681 	if (ret == 0 || !new)
682 		return ret;
683 
684 	/*
685 	 * If we get -EIO above, zero out any newly allocated blocks
686 	 * to avoid exposing stale data.
687 	 */
688 	bh = head;
689 	block_start = 0;
690 	do {
691 		block_end = block_start + bsize;
692 		if (block_end <= from)
693 			goto next_bh;
694 		if (block_start >= to)
695 			break;
696 
697 		zero_user(page, block_start, bh->b_size);
698 		set_buffer_uptodate(bh);
699 		mark_buffer_dirty(bh);
700 
701 next_bh:
702 		block_start = block_end;
703 		bh = bh->b_this_page;
704 	} while (bh != head);
705 
706 	return ret;
707 }
708 
709 #if (PAGE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
710 #define OCFS2_MAX_CTXT_PAGES	1
711 #else
712 #define OCFS2_MAX_CTXT_PAGES	(OCFS2_MAX_CLUSTERSIZE / PAGE_SIZE)
713 #endif
714 
715 #define OCFS2_MAX_CLUSTERS_PER_PAGE	(PAGE_SIZE / OCFS2_MIN_CLUSTERSIZE)
716 
717 struct ocfs2_unwritten_extent {
718 	struct list_head	ue_node;
719 	struct list_head	ue_ip_node;
720 	u32			ue_cpos;
721 	u32			ue_phys;
722 };
723 
724 /*
725  * Describe the state of a single cluster to be written to.
726  */
727 struct ocfs2_write_cluster_desc {
728 	u32		c_cpos;
729 	u32		c_phys;
730 	/*
731 	 * Give this a unique field because c_phys eventually gets
732 	 * filled.
733 	 */
734 	unsigned	c_new;
735 	unsigned	c_clear_unwritten;
736 	unsigned	c_needs_zero;
737 };
738 
739 struct ocfs2_write_ctxt {
740 	/* Logical cluster position / len of write */
741 	u32				w_cpos;
742 	u32				w_clen;
743 
744 	/* First cluster allocated in a nonsparse extend */
745 	u32				w_first_new_cpos;
746 
747 	/* Type of caller. Must be one of buffer, mmap, direct.  */
748 	ocfs2_write_type_t		w_type;
749 
750 	struct ocfs2_write_cluster_desc	w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
751 
752 	/*
753 	 * This is true if page_size > cluster_size.
754 	 *
755 	 * It triggers a set of special cases during write which might
756 	 * have to deal with allocating writes to partial pages.
757 	 */
758 	unsigned int			w_large_pages;
759 
760 	/*
761 	 * Pages involved in this write.
762 	 *
763 	 * w_target_page is the page being written to by the user.
764 	 *
765 	 * w_pages is an array of pages which always contains
766 	 * w_target_page, and in the case of an allocating write with
767 	 * page_size < cluster size, it will contain zero'd and mapped
768 	 * pages adjacent to w_target_page which need to be written
769 	 * out in so that future reads from that region will get
770 	 * zero's.
771 	 */
772 	unsigned int			w_num_pages;
773 	struct page			*w_pages[OCFS2_MAX_CTXT_PAGES];
774 	struct page			*w_target_page;
775 
776 	/*
777 	 * w_target_locked is used for page_mkwrite path indicating no unlocking
778 	 * against w_target_page in ocfs2_write_end_nolock.
779 	 */
780 	unsigned int			w_target_locked:1;
781 
782 	/*
783 	 * ocfs2_write_end() uses this to know what the real range to
784 	 * write in the target should be.
785 	 */
786 	unsigned int			w_target_from;
787 	unsigned int			w_target_to;
788 
789 	/*
790 	 * We could use journal_current_handle() but this is cleaner,
791 	 * IMHO -Mark
792 	 */
793 	handle_t			*w_handle;
794 
795 	struct buffer_head		*w_di_bh;
796 
797 	struct ocfs2_cached_dealloc_ctxt w_dealloc;
798 
799 	struct list_head		w_unwritten_list;
800 	unsigned int			w_unwritten_count;
801 };
802 
ocfs2_unlock_and_free_pages(struct page ** pages,int num_pages)803 void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
804 {
805 	int i;
806 
807 	for(i = 0; i < num_pages; i++) {
808 		if (pages[i]) {
809 			unlock_page(pages[i]);
810 			mark_page_accessed(pages[i]);
811 			put_page(pages[i]);
812 		}
813 	}
814 }
815 
ocfs2_unlock_pages(struct ocfs2_write_ctxt * wc)816 static void ocfs2_unlock_pages(struct ocfs2_write_ctxt *wc)
817 {
818 	int i;
819 
820 	/*
821 	 * w_target_locked is only set to true in the page_mkwrite() case.
822 	 * The intent is to allow us to lock the target page from write_begin()
823 	 * to write_end(). The caller must hold a ref on w_target_page.
824 	 */
825 	if (wc->w_target_locked) {
826 		BUG_ON(!wc->w_target_page);
827 		for (i = 0; i < wc->w_num_pages; i++) {
828 			if (wc->w_target_page == wc->w_pages[i]) {
829 				wc->w_pages[i] = NULL;
830 				break;
831 			}
832 		}
833 		mark_page_accessed(wc->w_target_page);
834 		put_page(wc->w_target_page);
835 	}
836 	ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
837 }
838 
ocfs2_free_unwritten_list(struct inode * inode,struct list_head * head)839 static void ocfs2_free_unwritten_list(struct inode *inode,
840 				 struct list_head *head)
841 {
842 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
843 	struct ocfs2_unwritten_extent *ue = NULL, *tmp = NULL;
844 
845 	list_for_each_entry_safe(ue, tmp, head, ue_node) {
846 		list_del(&ue->ue_node);
847 		spin_lock(&oi->ip_lock);
848 		list_del(&ue->ue_ip_node);
849 		spin_unlock(&oi->ip_lock);
850 		kfree(ue);
851 	}
852 }
853 
ocfs2_free_write_ctxt(struct inode * inode,struct ocfs2_write_ctxt * wc)854 static void ocfs2_free_write_ctxt(struct inode *inode,
855 				  struct ocfs2_write_ctxt *wc)
856 {
857 	ocfs2_free_unwritten_list(inode, &wc->w_unwritten_list);
858 	ocfs2_unlock_pages(wc);
859 	brelse(wc->w_di_bh);
860 	kfree(wc);
861 }
862 
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)863 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
864 				  struct ocfs2_super *osb, loff_t pos,
865 				  unsigned len, ocfs2_write_type_t type,
866 				  struct buffer_head *di_bh)
867 {
868 	u32 cend;
869 	struct ocfs2_write_ctxt *wc;
870 
871 	wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
872 	if (!wc)
873 		return -ENOMEM;
874 
875 	wc->w_cpos = pos >> osb->s_clustersize_bits;
876 	wc->w_first_new_cpos = UINT_MAX;
877 	cend = (pos + len - 1) >> osb->s_clustersize_bits;
878 	wc->w_clen = cend - wc->w_cpos + 1;
879 	get_bh(di_bh);
880 	wc->w_di_bh = di_bh;
881 	wc->w_type = type;
882 
883 	if (unlikely(PAGE_SHIFT > osb->s_clustersize_bits))
884 		wc->w_large_pages = 1;
885 	else
886 		wc->w_large_pages = 0;
887 
888 	ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
889 	INIT_LIST_HEAD(&wc->w_unwritten_list);
890 
891 	*wcp = wc;
892 
893 	return 0;
894 }
895 
896 /*
897  * If a page has any new buffers, zero them out here, and mark them uptodate
898  * and dirty so they'll be written out (in order to prevent uninitialised
899  * block data from leaking). And clear the new bit.
900  */
ocfs2_zero_new_buffers(struct page * page,unsigned from,unsigned to)901 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
902 {
903 	unsigned int block_start, block_end;
904 	struct buffer_head *head, *bh;
905 
906 	BUG_ON(!PageLocked(page));
907 	if (!page_has_buffers(page))
908 		return;
909 
910 	bh = head = page_buffers(page);
911 	block_start = 0;
912 	do {
913 		block_end = block_start + bh->b_size;
914 
915 		if (buffer_new(bh)) {
916 			if (block_end > from && block_start < to) {
917 				if (!PageUptodate(page)) {
918 					unsigned start, end;
919 
920 					start = max(from, block_start);
921 					end = min(to, block_end);
922 
923 					zero_user_segment(page, start, end);
924 					set_buffer_uptodate(bh);
925 				}
926 
927 				clear_buffer_new(bh);
928 				mark_buffer_dirty(bh);
929 			}
930 		}
931 
932 		block_start = block_end;
933 		bh = bh->b_this_page;
934 	} while (bh != head);
935 }
936 
937 /*
938  * Only called when we have a failure during allocating write to write
939  * zero's to the newly allocated region.
940  */
ocfs2_write_failure(struct inode * inode,struct ocfs2_write_ctxt * wc,loff_t user_pos,unsigned user_len)941 static void ocfs2_write_failure(struct inode *inode,
942 				struct ocfs2_write_ctxt *wc,
943 				loff_t user_pos, unsigned user_len)
944 {
945 	int i;
946 	unsigned from = user_pos & (PAGE_SIZE - 1),
947 		to = user_pos + user_len;
948 	struct page *tmppage;
949 
950 	if (wc->w_target_page)
951 		ocfs2_zero_new_buffers(wc->w_target_page, from, to);
952 
953 	for(i = 0; i < wc->w_num_pages; i++) {
954 		tmppage = wc->w_pages[i];
955 
956 		if (tmppage && page_has_buffers(tmppage)) {
957 			if (ocfs2_should_order_data(inode))
958 				ocfs2_jbd2_file_inode(wc->w_handle, inode);
959 
960 			block_commit_write(tmppage, from, to);
961 		}
962 	}
963 }
964 
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)965 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
966 					struct ocfs2_write_ctxt *wc,
967 					struct page *page, u32 cpos,
968 					loff_t user_pos, unsigned user_len,
969 					int new)
970 {
971 	int ret;
972 	unsigned int map_from = 0, map_to = 0;
973 	unsigned int cluster_start, cluster_end;
974 	unsigned int user_data_from = 0, user_data_to = 0;
975 
976 	ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
977 					&cluster_start, &cluster_end);
978 
979 	/* treat the write as new if the a hole/lseek spanned across
980 	 * the page boundary.
981 	 */
982 	new = new | ((i_size_read(inode) <= page_offset(page)) &&
983 			(page_offset(page) <= user_pos));
984 
985 	if (page == wc->w_target_page) {
986 		map_from = user_pos & (PAGE_SIZE - 1);
987 		map_to = map_from + user_len;
988 
989 		if (new)
990 			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
991 						    cluster_start, cluster_end,
992 						    new);
993 		else
994 			ret = ocfs2_map_page_blocks(page, p_blkno, inode,
995 						    map_from, map_to, new);
996 		if (ret) {
997 			mlog_errno(ret);
998 			goto out;
999 		}
1000 
1001 		user_data_from = map_from;
1002 		user_data_to = map_to;
1003 		if (new) {
1004 			map_from = cluster_start;
1005 			map_to = cluster_end;
1006 		}
1007 	} else {
1008 		/*
1009 		 * If we haven't allocated the new page yet, we
1010 		 * shouldn't be writing it out without copying user
1011 		 * data. This is likely a math error from the caller.
1012 		 */
1013 		BUG_ON(!new);
1014 
1015 		map_from = cluster_start;
1016 		map_to = cluster_end;
1017 
1018 		ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1019 					    cluster_start, cluster_end, new);
1020 		if (ret) {
1021 			mlog_errno(ret);
1022 			goto out;
1023 		}
1024 	}
1025 
1026 	/*
1027 	 * Parts of newly allocated pages need to be zero'd.
1028 	 *
1029 	 * Above, we have also rewritten 'to' and 'from' - as far as
1030 	 * the rest of the function is concerned, the entire cluster
1031 	 * range inside of a page needs to be written.
1032 	 *
1033 	 * We can skip this if the page is up to date - it's already
1034 	 * been zero'd from being read in as a hole.
1035 	 */
1036 	if (new && !PageUptodate(page))
1037 		ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1038 					 cpos, user_data_from, user_data_to);
1039 
1040 	flush_dcache_page(page);
1041 
1042 out:
1043 	return ret;
1044 }
1045 
1046 /*
1047  * This function will only grab one clusters worth of pages.
1048  */
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)1049 static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1050 				      struct ocfs2_write_ctxt *wc,
1051 				      u32 cpos, loff_t user_pos,
1052 				      unsigned user_len, int new,
1053 				      struct page *mmap_page)
1054 {
1055 	int ret = 0, i;
1056 	unsigned long start, target_index, end_index, index;
1057 	struct inode *inode = mapping->host;
1058 	loff_t last_byte;
1059 
1060 	target_index = user_pos >> PAGE_SHIFT;
1061 
1062 	/*
1063 	 * Figure out how many pages we'll be manipulating here. For
1064 	 * non allocating write, we just change the one
1065 	 * page. Otherwise, we'll need a whole clusters worth.  If we're
1066 	 * writing past i_size, we only need enough pages to cover the
1067 	 * last page of the write.
1068 	 */
1069 	if (new) {
1070 		wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1071 		start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1072 		/*
1073 		 * We need the index *past* the last page we could possibly
1074 		 * touch.  This is the page past the end of the write or
1075 		 * i_size, whichever is greater.
1076 		 */
1077 		last_byte = max(user_pos + user_len, i_size_read(inode));
1078 		BUG_ON(last_byte < 1);
1079 		end_index = ((last_byte - 1) >> PAGE_SHIFT) + 1;
1080 		if ((start + wc->w_num_pages) > end_index)
1081 			wc->w_num_pages = end_index - start;
1082 	} else {
1083 		wc->w_num_pages = 1;
1084 		start = target_index;
1085 	}
1086 	end_index = (user_pos + user_len - 1) >> PAGE_SHIFT;
1087 
1088 	for(i = 0; i < wc->w_num_pages; i++) {
1089 		index = start + i;
1090 
1091 		if (index >= target_index && index <= end_index &&
1092 		    wc->w_type == OCFS2_WRITE_MMAP) {
1093 			/*
1094 			 * ocfs2_pagemkwrite() is a little different
1095 			 * and wants us to directly use the page
1096 			 * passed in.
1097 			 */
1098 			lock_page(mmap_page);
1099 
1100 			/* Exit and let the caller retry */
1101 			if (mmap_page->mapping != mapping) {
1102 				WARN_ON(mmap_page->mapping);
1103 				unlock_page(mmap_page);
1104 				ret = -EAGAIN;
1105 				goto out;
1106 			}
1107 
1108 			get_page(mmap_page);
1109 			wc->w_pages[i] = mmap_page;
1110 			wc->w_target_locked = true;
1111 		} else if (index >= target_index && index <= end_index &&
1112 			   wc->w_type == OCFS2_WRITE_DIRECT) {
1113 			/* Direct write has no mapping page. */
1114 			wc->w_pages[i] = NULL;
1115 			continue;
1116 		} else {
1117 			wc->w_pages[i] = find_or_create_page(mapping, index,
1118 							     GFP_NOFS);
1119 			if (!wc->w_pages[i]) {
1120 				ret = -ENOMEM;
1121 				mlog_errno(ret);
1122 				goto out;
1123 			}
1124 		}
1125 		wait_for_stable_page(wc->w_pages[i]);
1126 
1127 		if (index == target_index)
1128 			wc->w_target_page = wc->w_pages[i];
1129 	}
1130 out:
1131 	if (ret)
1132 		wc->w_target_locked = false;
1133 	return ret;
1134 }
1135 
1136 /*
1137  * Prepare a single cluster for write one cluster into the file.
1138  */
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)1139 static int ocfs2_write_cluster(struct address_space *mapping,
1140 			       u32 *phys, unsigned int new,
1141 			       unsigned int clear_unwritten,
1142 			       unsigned int should_zero,
1143 			       struct ocfs2_alloc_context *data_ac,
1144 			       struct ocfs2_alloc_context *meta_ac,
1145 			       struct ocfs2_write_ctxt *wc, u32 cpos,
1146 			       loff_t user_pos, unsigned user_len)
1147 {
1148 	int ret, i;
1149 	u64 p_blkno;
1150 	struct inode *inode = mapping->host;
1151 	struct ocfs2_extent_tree et;
1152 	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
1153 
1154 	if (new) {
1155 		u32 tmp_pos;
1156 
1157 		/*
1158 		 * This is safe to call with the page locks - it won't take
1159 		 * any additional semaphores or cluster locks.
1160 		 */
1161 		tmp_pos = cpos;
1162 		ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1163 					   &tmp_pos, 1, !clear_unwritten,
1164 					   wc->w_di_bh, wc->w_handle,
1165 					   data_ac, meta_ac, NULL);
1166 		/*
1167 		 * This shouldn't happen because we must have already
1168 		 * calculated the correct meta data allocation required. The
1169 		 * internal tree allocation code should know how to increase
1170 		 * transaction credits itself.
1171 		 *
1172 		 * If need be, we could handle -EAGAIN for a
1173 		 * RESTART_TRANS here.
1174 		 */
1175 		mlog_bug_on_msg(ret == -EAGAIN,
1176 				"Inode %llu: EAGAIN return during allocation.\n",
1177 				(unsigned long long)OCFS2_I(inode)->ip_blkno);
1178 		if (ret < 0) {
1179 			mlog_errno(ret);
1180 			goto out;
1181 		}
1182 	} else if (clear_unwritten) {
1183 		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1184 					      wc->w_di_bh);
1185 		ret = ocfs2_mark_extent_written(inode, &et,
1186 						wc->w_handle, cpos, 1, *phys,
1187 						meta_ac, &wc->w_dealloc);
1188 		if (ret < 0) {
1189 			mlog_errno(ret);
1190 			goto out;
1191 		}
1192 	}
1193 
1194 	/*
1195 	 * The only reason this should fail is due to an inability to
1196 	 * find the extent added.
1197 	 */
1198 	ret = ocfs2_get_clusters(inode, cpos, phys, NULL, NULL);
1199 	if (ret < 0) {
1200 		mlog(ML_ERROR, "Get physical blkno failed for inode %llu, "
1201 			    "at logical cluster %u",
1202 			    (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos);
1203 		goto out;
1204 	}
1205 
1206 	BUG_ON(*phys == 0);
1207 
1208 	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, *phys);
1209 	if (!should_zero)
1210 		p_blkno += (user_pos >> inode->i_sb->s_blocksize_bits) & (u64)(bpc - 1);
1211 
1212 	for(i = 0; i < wc->w_num_pages; i++) {
1213 		int tmpret;
1214 
1215 		/* This is the direct io target page. */
1216 		if (wc->w_pages[i] == NULL) {
1217 			p_blkno++;
1218 			continue;
1219 		}
1220 
1221 		tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1222 						      wc->w_pages[i], cpos,
1223 						      user_pos, user_len,
1224 						      should_zero);
1225 		if (tmpret) {
1226 			mlog_errno(tmpret);
1227 			if (ret == 0)
1228 				ret = tmpret;
1229 		}
1230 	}
1231 
1232 	/*
1233 	 * We only have cleanup to do in case of allocating write.
1234 	 */
1235 	if (ret && new)
1236 		ocfs2_write_failure(inode, wc, user_pos, user_len);
1237 
1238 out:
1239 
1240 	return ret;
1241 }
1242 
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)1243 static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1244 				       struct ocfs2_alloc_context *data_ac,
1245 				       struct ocfs2_alloc_context *meta_ac,
1246 				       struct ocfs2_write_ctxt *wc,
1247 				       loff_t pos, unsigned len)
1248 {
1249 	int ret, i;
1250 	loff_t cluster_off;
1251 	unsigned int local_len = len;
1252 	struct ocfs2_write_cluster_desc *desc;
1253 	struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1254 
1255 	for (i = 0; i < wc->w_clen; i++) {
1256 		desc = &wc->w_desc[i];
1257 
1258 		/*
1259 		 * We have to make sure that the total write passed in
1260 		 * doesn't extend past a single cluster.
1261 		 */
1262 		local_len = len;
1263 		cluster_off = pos & (osb->s_clustersize - 1);
1264 		if ((cluster_off + local_len) > osb->s_clustersize)
1265 			local_len = osb->s_clustersize - cluster_off;
1266 
1267 		ret = ocfs2_write_cluster(mapping, &desc->c_phys,
1268 					  desc->c_new,
1269 					  desc->c_clear_unwritten,
1270 					  desc->c_needs_zero,
1271 					  data_ac, meta_ac,
1272 					  wc, desc->c_cpos, pos, local_len);
1273 		if (ret) {
1274 			mlog_errno(ret);
1275 			goto out;
1276 		}
1277 
1278 		len -= local_len;
1279 		pos += local_len;
1280 	}
1281 
1282 	ret = 0;
1283 out:
1284 	return ret;
1285 }
1286 
1287 /*
1288  * ocfs2_write_end() wants to know which parts of the target page it
1289  * should complete the write on. It's easiest to compute them ahead of
1290  * time when a more complete view of the write is available.
1291  */
ocfs2_set_target_boundaries(struct ocfs2_super * osb,struct ocfs2_write_ctxt * wc,loff_t pos,unsigned len,int alloc)1292 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1293 					struct ocfs2_write_ctxt *wc,
1294 					loff_t pos, unsigned len, int alloc)
1295 {
1296 	struct ocfs2_write_cluster_desc *desc;
1297 
1298 	wc->w_target_from = pos & (PAGE_SIZE - 1);
1299 	wc->w_target_to = wc->w_target_from + len;
1300 
1301 	if (alloc == 0)
1302 		return;
1303 
1304 	/*
1305 	 * Allocating write - we may have different boundaries based
1306 	 * on page size and cluster size.
1307 	 *
1308 	 * NOTE: We can no longer compute one value from the other as
1309 	 * the actual write length and user provided length may be
1310 	 * different.
1311 	 */
1312 
1313 	if (wc->w_large_pages) {
1314 		/*
1315 		 * We only care about the 1st and last cluster within
1316 		 * our range and whether they should be zero'd or not. Either
1317 		 * value may be extended out to the start/end of a
1318 		 * newly allocated cluster.
1319 		 */
1320 		desc = &wc->w_desc[0];
1321 		if (desc->c_needs_zero)
1322 			ocfs2_figure_cluster_boundaries(osb,
1323 							desc->c_cpos,
1324 							&wc->w_target_from,
1325 							NULL);
1326 
1327 		desc = &wc->w_desc[wc->w_clen - 1];
1328 		if (desc->c_needs_zero)
1329 			ocfs2_figure_cluster_boundaries(osb,
1330 							desc->c_cpos,
1331 							NULL,
1332 							&wc->w_target_to);
1333 	} else {
1334 		wc->w_target_from = 0;
1335 		wc->w_target_to = PAGE_SIZE;
1336 	}
1337 }
1338 
1339 /*
1340  * Check if this extent is marked UNWRITTEN by direct io. If so, we need not to
1341  * do the zero work. And should not to clear UNWRITTEN since it will be cleared
1342  * by the direct io procedure.
1343  * If this is a new extent that allocated by direct io, we should mark it in
1344  * the ip_unwritten_list.
1345  */
ocfs2_unwritten_check(struct inode * inode,struct ocfs2_write_ctxt * wc,struct ocfs2_write_cluster_desc * desc)1346 static int ocfs2_unwritten_check(struct inode *inode,
1347 				 struct ocfs2_write_ctxt *wc,
1348 				 struct ocfs2_write_cluster_desc *desc)
1349 {
1350 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1351 	struct ocfs2_unwritten_extent *ue = NULL, *new = NULL;
1352 	int ret = 0;
1353 
1354 	if (!desc->c_needs_zero)
1355 		return 0;
1356 
1357 retry:
1358 	spin_lock(&oi->ip_lock);
1359 	/* Needs not to zero no metter buffer or direct. The one who is zero
1360 	 * the cluster is doing zero. And he will clear unwritten after all
1361 	 * cluster io finished. */
1362 	list_for_each_entry(ue, &oi->ip_unwritten_list, ue_ip_node) {
1363 		if (desc->c_cpos == ue->ue_cpos) {
1364 			BUG_ON(desc->c_new);
1365 			desc->c_needs_zero = 0;
1366 			desc->c_clear_unwritten = 0;
1367 			goto unlock;
1368 		}
1369 	}
1370 
1371 	if (wc->w_type != OCFS2_WRITE_DIRECT)
1372 		goto unlock;
1373 
1374 	if (new == NULL) {
1375 		spin_unlock(&oi->ip_lock);
1376 		new = kmalloc(sizeof(struct ocfs2_unwritten_extent),
1377 			     GFP_NOFS);
1378 		if (new == NULL) {
1379 			ret = -ENOMEM;
1380 			goto out;
1381 		}
1382 		goto retry;
1383 	}
1384 	/* This direct write will doing zero. */
1385 	new->ue_cpos = desc->c_cpos;
1386 	new->ue_phys = desc->c_phys;
1387 	desc->c_clear_unwritten = 0;
1388 	list_add_tail(&new->ue_ip_node, &oi->ip_unwritten_list);
1389 	list_add_tail(&new->ue_node, &wc->w_unwritten_list);
1390 	wc->w_unwritten_count++;
1391 	new = NULL;
1392 unlock:
1393 	spin_unlock(&oi->ip_lock);
1394 out:
1395 	if (new)
1396 		kfree(new);
1397 	return ret;
1398 }
1399 
1400 /*
1401  * Populate each single-cluster write descriptor in the write context
1402  * with information about the i/o to be done.
1403  *
1404  * Returns the number of clusters that will have to be allocated, as
1405  * well as a worst case estimate of the number of extent records that
1406  * would have to be created during a write to an unwritten region.
1407  */
ocfs2_populate_write_desc(struct inode * inode,struct ocfs2_write_ctxt * wc,unsigned int * clusters_to_alloc,unsigned int * extents_to_split)1408 static int ocfs2_populate_write_desc(struct inode *inode,
1409 				     struct ocfs2_write_ctxt *wc,
1410 				     unsigned int *clusters_to_alloc,
1411 				     unsigned int *extents_to_split)
1412 {
1413 	int ret;
1414 	struct ocfs2_write_cluster_desc *desc;
1415 	unsigned int num_clusters = 0;
1416 	unsigned int ext_flags = 0;
1417 	u32 phys = 0;
1418 	int i;
1419 
1420 	*clusters_to_alloc = 0;
1421 	*extents_to_split = 0;
1422 
1423 	for (i = 0; i < wc->w_clen; i++) {
1424 		desc = &wc->w_desc[i];
1425 		desc->c_cpos = wc->w_cpos + i;
1426 
1427 		if (num_clusters == 0) {
1428 			/*
1429 			 * Need to look up the next extent record.
1430 			 */
1431 			ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1432 						 &num_clusters, &ext_flags);
1433 			if (ret) {
1434 				mlog_errno(ret);
1435 				goto out;
1436 			}
1437 
1438 			/* We should already CoW the refcountd extent. */
1439 			BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1440 
1441 			/*
1442 			 * Assume worst case - that we're writing in
1443 			 * the middle of the extent.
1444 			 *
1445 			 * We can assume that the write proceeds from
1446 			 * left to right, in which case the extent
1447 			 * insert code is smart enough to coalesce the
1448 			 * next splits into the previous records created.
1449 			 */
1450 			if (ext_flags & OCFS2_EXT_UNWRITTEN)
1451 				*extents_to_split = *extents_to_split + 2;
1452 		} else if (phys) {
1453 			/*
1454 			 * Only increment phys if it doesn't describe
1455 			 * a hole.
1456 			 */
1457 			phys++;
1458 		}
1459 
1460 		/*
1461 		 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1462 		 * file that got extended.  w_first_new_cpos tells us
1463 		 * where the newly allocated clusters are so we can
1464 		 * zero them.
1465 		 */
1466 		if (desc->c_cpos >= wc->w_first_new_cpos) {
1467 			BUG_ON(phys == 0);
1468 			desc->c_needs_zero = 1;
1469 		}
1470 
1471 		desc->c_phys = phys;
1472 		if (phys == 0) {
1473 			desc->c_new = 1;
1474 			desc->c_needs_zero = 1;
1475 			desc->c_clear_unwritten = 1;
1476 			*clusters_to_alloc = *clusters_to_alloc + 1;
1477 		}
1478 
1479 		if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1480 			desc->c_clear_unwritten = 1;
1481 			desc->c_needs_zero = 1;
1482 		}
1483 
1484 		ret = ocfs2_unwritten_check(inode, wc, desc);
1485 		if (ret) {
1486 			mlog_errno(ret);
1487 			goto out;
1488 		}
1489 
1490 		num_clusters--;
1491 	}
1492 
1493 	ret = 0;
1494 out:
1495 	return ret;
1496 }
1497 
ocfs2_write_begin_inline(struct address_space * mapping,struct inode * inode,struct ocfs2_write_ctxt * wc)1498 static int ocfs2_write_begin_inline(struct address_space *mapping,
1499 				    struct inode *inode,
1500 				    struct ocfs2_write_ctxt *wc)
1501 {
1502 	int ret;
1503 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1504 	struct page *page;
1505 	handle_t *handle;
1506 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1507 
1508 	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1509 	if (IS_ERR(handle)) {
1510 		ret = PTR_ERR(handle);
1511 		mlog_errno(ret);
1512 		goto out;
1513 	}
1514 
1515 	page = find_or_create_page(mapping, 0, GFP_NOFS);
1516 	if (!page) {
1517 		ocfs2_commit_trans(osb, handle);
1518 		ret = -ENOMEM;
1519 		mlog_errno(ret);
1520 		goto out;
1521 	}
1522 	/*
1523 	 * If we don't set w_num_pages then this page won't get unlocked
1524 	 * and freed on cleanup of the write context.
1525 	 */
1526 	wc->w_pages[0] = wc->w_target_page = page;
1527 	wc->w_num_pages = 1;
1528 
1529 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1530 				      OCFS2_JOURNAL_ACCESS_WRITE);
1531 	if (ret) {
1532 		ocfs2_commit_trans(osb, handle);
1533 
1534 		mlog_errno(ret);
1535 		goto out;
1536 	}
1537 
1538 	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1539 		ocfs2_set_inode_data_inline(inode, di);
1540 
1541 	if (!PageUptodate(page)) {
1542 		ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1543 		if (ret) {
1544 			ocfs2_commit_trans(osb, handle);
1545 
1546 			goto out;
1547 		}
1548 	}
1549 
1550 	wc->w_handle = handle;
1551 out:
1552 	return ret;
1553 }
1554 
ocfs2_size_fits_inline_data(struct buffer_head * di_bh,u64 new_size)1555 int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1556 {
1557 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1558 
1559 	if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1560 		return 1;
1561 	return 0;
1562 }
1563 
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)1564 static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1565 					  struct inode *inode, loff_t pos,
1566 					  unsigned len, struct page *mmap_page,
1567 					  struct ocfs2_write_ctxt *wc)
1568 {
1569 	int ret, written = 0;
1570 	loff_t end = pos + len;
1571 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1572 	struct ocfs2_dinode *di = NULL;
1573 
1574 	trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1575 					     len, (unsigned long long)pos,
1576 					     oi->ip_dyn_features);
1577 
1578 	/*
1579 	 * Handle inodes which already have inline data 1st.
1580 	 */
1581 	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1582 		if (mmap_page == NULL &&
1583 		    ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1584 			goto do_inline_write;
1585 
1586 		/*
1587 		 * The write won't fit - we have to give this inode an
1588 		 * inline extent list now.
1589 		 */
1590 		ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1591 		if (ret)
1592 			mlog_errno(ret);
1593 		goto out;
1594 	}
1595 
1596 	/*
1597 	 * Check whether the inode can accept inline data.
1598 	 */
1599 	if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1600 		return 0;
1601 
1602 	/*
1603 	 * Check whether the write can fit.
1604 	 */
1605 	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1606 	if (mmap_page ||
1607 	    end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1608 		return 0;
1609 
1610 do_inline_write:
1611 	ret = ocfs2_write_begin_inline(mapping, inode, wc);
1612 	if (ret) {
1613 		mlog_errno(ret);
1614 		goto out;
1615 	}
1616 
1617 	/*
1618 	 * This signals to the caller that the data can be written
1619 	 * inline.
1620 	 */
1621 	written = 1;
1622 out:
1623 	return written ? written : ret;
1624 }
1625 
1626 /*
1627  * This function only does anything for file systems which can't
1628  * handle sparse files.
1629  *
1630  * What we want to do here is fill in any hole between the current end
1631  * of allocation and the end of our write. That way the rest of the
1632  * write path can treat it as an non-allocating write, which has no
1633  * special case code for sparse/nonsparse files.
1634  */
ocfs2_expand_nonsparse_inode(struct inode * inode,struct buffer_head * di_bh,loff_t pos,unsigned len,struct ocfs2_write_ctxt * wc)1635 static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1636 					struct buffer_head *di_bh,
1637 					loff_t pos, unsigned len,
1638 					struct ocfs2_write_ctxt *wc)
1639 {
1640 	int ret;
1641 	loff_t newsize = pos + len;
1642 
1643 	BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1644 
1645 	if (newsize <= i_size_read(inode))
1646 		return 0;
1647 
1648 	ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1649 	if (ret)
1650 		mlog_errno(ret);
1651 
1652 	/* There is no wc if this is call from direct. */
1653 	if (wc)
1654 		wc->w_first_new_cpos =
1655 			ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1656 
1657 	return ret;
1658 }
1659 
ocfs2_zero_tail(struct inode * inode,struct buffer_head * di_bh,loff_t pos)1660 static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1661 			   loff_t pos)
1662 {
1663 	int ret = 0;
1664 
1665 	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1666 	if (pos > i_size_read(inode))
1667 		ret = ocfs2_zero_extend(inode, di_bh, pos);
1668 
1669 	return ret;
1670 }
1671 
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)1672 int ocfs2_write_begin_nolock(struct address_space *mapping,
1673 			     loff_t pos, unsigned len, ocfs2_write_type_t type,
1674 			     struct page **pagep, void **fsdata,
1675 			     struct buffer_head *di_bh, struct page *mmap_page)
1676 {
1677 	int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1678 	unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1679 	struct ocfs2_write_ctxt *wc;
1680 	struct inode *inode = mapping->host;
1681 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1682 	struct ocfs2_dinode *di;
1683 	struct ocfs2_alloc_context *data_ac = NULL;
1684 	struct ocfs2_alloc_context *meta_ac = NULL;
1685 	handle_t *handle;
1686 	struct ocfs2_extent_tree et;
1687 	int try_free = 1, ret1;
1688 
1689 try_again:
1690 	ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, type, di_bh);
1691 	if (ret) {
1692 		mlog_errno(ret);
1693 		return ret;
1694 	}
1695 
1696 	if (ocfs2_supports_inline_data(osb)) {
1697 		ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1698 						     mmap_page, wc);
1699 		if (ret == 1) {
1700 			ret = 0;
1701 			goto success;
1702 		}
1703 		if (ret < 0) {
1704 			mlog_errno(ret);
1705 			goto out;
1706 		}
1707 	}
1708 
1709 	/* Direct io change i_size late, should not zero tail here. */
1710 	if (type != OCFS2_WRITE_DIRECT) {
1711 		if (ocfs2_sparse_alloc(osb))
1712 			ret = ocfs2_zero_tail(inode, di_bh, pos);
1713 		else
1714 			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
1715 							   len, wc);
1716 		if (ret) {
1717 			mlog_errno(ret);
1718 			goto out;
1719 		}
1720 	}
1721 
1722 	ret = ocfs2_check_range_for_refcount(inode, pos, len);
1723 	if (ret < 0) {
1724 		mlog_errno(ret);
1725 		goto out;
1726 	} else if (ret == 1) {
1727 		clusters_need = wc->w_clen;
1728 		ret = ocfs2_refcount_cow(inode, di_bh,
1729 					 wc->w_cpos, wc->w_clen, UINT_MAX);
1730 		if (ret) {
1731 			mlog_errno(ret);
1732 			goto out;
1733 		}
1734 	}
1735 
1736 	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1737 					&extents_to_split);
1738 	if (ret) {
1739 		mlog_errno(ret);
1740 		goto out;
1741 	}
1742 	clusters_need += clusters_to_alloc;
1743 
1744 	di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1745 
1746 	trace_ocfs2_write_begin_nolock(
1747 			(unsigned long long)OCFS2_I(inode)->ip_blkno,
1748 			(long long)i_size_read(inode),
1749 			le32_to_cpu(di->i_clusters),
1750 			pos, len, type, mmap_page,
1751 			clusters_to_alloc, extents_to_split);
1752 
1753 	/*
1754 	 * We set w_target_from, w_target_to here so that
1755 	 * ocfs2_write_end() knows which range in the target page to
1756 	 * write out. An allocation requires that we write the entire
1757 	 * cluster range.
1758 	 */
1759 	if (clusters_to_alloc || extents_to_split) {
1760 		/*
1761 		 * XXX: We are stretching the limits of
1762 		 * ocfs2_lock_allocators(). It greatly over-estimates
1763 		 * the work to be done.
1764 		 */
1765 		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1766 					      wc->w_di_bh);
1767 		ret = ocfs2_lock_allocators(inode, &et,
1768 					    clusters_to_alloc, extents_to_split,
1769 					    &data_ac, &meta_ac);
1770 		if (ret) {
1771 			mlog_errno(ret);
1772 			goto out;
1773 		}
1774 
1775 		if (data_ac)
1776 			data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1777 
1778 		credits = ocfs2_calc_extend_credits(inode->i_sb,
1779 						    &di->id2.i_list);
1780 	} else if (type == OCFS2_WRITE_DIRECT)
1781 		/* direct write needs not to start trans if no extents alloc. */
1782 		goto success;
1783 
1784 	/*
1785 	 * We have to zero sparse allocated clusters, unwritten extent clusters,
1786 	 * and non-sparse clusters we just extended.  For non-sparse writes,
1787 	 * we know zeros will only be needed in the first and/or last cluster.
1788 	 */
1789 	if (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1790 			   wc->w_desc[wc->w_clen - 1].c_needs_zero))
1791 		cluster_of_pages = 1;
1792 	else
1793 		cluster_of_pages = 0;
1794 
1795 	ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1796 
1797 	handle = ocfs2_start_trans(osb, credits);
1798 	if (IS_ERR(handle)) {
1799 		ret = PTR_ERR(handle);
1800 		mlog_errno(ret);
1801 		goto out;
1802 	}
1803 
1804 	wc->w_handle = handle;
1805 
1806 	if (clusters_to_alloc) {
1807 		ret = dquot_alloc_space_nodirty(inode,
1808 			ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1809 		if (ret)
1810 			goto out_commit;
1811 	}
1812 
1813 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1814 				      OCFS2_JOURNAL_ACCESS_WRITE);
1815 	if (ret) {
1816 		mlog_errno(ret);
1817 		goto out_quota;
1818 	}
1819 
1820 	/*
1821 	 * Fill our page array first. That way we've grabbed enough so
1822 	 * that we can zero and flush if we error after adding the
1823 	 * extent.
1824 	 */
1825 	ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
1826 					 cluster_of_pages, mmap_page);
1827 	if (ret && ret != -EAGAIN) {
1828 		mlog_errno(ret);
1829 		goto out_quota;
1830 	}
1831 
1832 	/*
1833 	 * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock
1834 	 * the target page. In this case, we exit with no error and no target
1835 	 * page. This will trigger the caller, page_mkwrite(), to re-try
1836 	 * the operation.
1837 	 */
1838 	if (ret == -EAGAIN) {
1839 		BUG_ON(wc->w_target_page);
1840 		ret = 0;
1841 		goto out_quota;
1842 	}
1843 
1844 	ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1845 					  len);
1846 	if (ret) {
1847 		mlog_errno(ret);
1848 		goto out_quota;
1849 	}
1850 
1851 	if (data_ac)
1852 		ocfs2_free_alloc_context(data_ac);
1853 	if (meta_ac)
1854 		ocfs2_free_alloc_context(meta_ac);
1855 
1856 success:
1857 	if (pagep)
1858 		*pagep = wc->w_target_page;
1859 	*fsdata = wc;
1860 	return 0;
1861 out_quota:
1862 	if (clusters_to_alloc)
1863 		dquot_free_space(inode,
1864 			  ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1865 out_commit:
1866 	ocfs2_commit_trans(osb, handle);
1867 
1868 out:
1869 	/*
1870 	 * The mmapped page won't be unlocked in ocfs2_free_write_ctxt(),
1871 	 * even in case of error here like ENOSPC and ENOMEM. So, we need
1872 	 * to unlock the target page manually to prevent deadlocks when
1873 	 * retrying again on ENOSPC, or when returning non-VM_FAULT_LOCKED
1874 	 * to VM code.
1875 	 */
1876 	if (wc->w_target_locked)
1877 		unlock_page(mmap_page);
1878 
1879 	ocfs2_free_write_ctxt(inode, wc);
1880 
1881 	if (data_ac) {
1882 		ocfs2_free_alloc_context(data_ac);
1883 		data_ac = NULL;
1884 	}
1885 	if (meta_ac) {
1886 		ocfs2_free_alloc_context(meta_ac);
1887 		meta_ac = NULL;
1888 	}
1889 
1890 	if (ret == -ENOSPC && try_free) {
1891 		/*
1892 		 * Try to free some truncate log so that we can have enough
1893 		 * clusters to allocate.
1894 		 */
1895 		try_free = 0;
1896 
1897 		ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1898 		if (ret1 == 1)
1899 			goto try_again;
1900 
1901 		if (ret1 < 0)
1902 			mlog_errno(ret1);
1903 	}
1904 
1905 	return ret;
1906 }
1907 
ocfs2_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)1908 static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1909 			     loff_t pos, unsigned len, unsigned flags,
1910 			     struct page **pagep, void **fsdata)
1911 {
1912 	int ret;
1913 	struct buffer_head *di_bh = NULL;
1914 	struct inode *inode = mapping->host;
1915 
1916 	ret = ocfs2_inode_lock(inode, &di_bh, 1);
1917 	if (ret) {
1918 		mlog_errno(ret);
1919 		return ret;
1920 	}
1921 
1922 	/*
1923 	 * Take alloc sem here to prevent concurrent lookups. That way
1924 	 * the mapping, zeroing and tree manipulation within
1925 	 * ocfs2_write() will be safe against ->readpage(). This
1926 	 * should also serve to lock out allocation from a shared
1927 	 * writeable region.
1928 	 */
1929 	down_write(&OCFS2_I(inode)->ip_alloc_sem);
1930 
1931 	ret = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_BUFFER,
1932 				       pagep, fsdata, di_bh, NULL);
1933 	if (ret) {
1934 		mlog_errno(ret);
1935 		goto out_fail;
1936 	}
1937 
1938 	brelse(di_bh);
1939 
1940 	return 0;
1941 
1942 out_fail:
1943 	up_write(&OCFS2_I(inode)->ip_alloc_sem);
1944 
1945 	brelse(di_bh);
1946 	ocfs2_inode_unlock(inode, 1);
1947 
1948 	return ret;
1949 }
1950 
ocfs2_write_end_inline(struct inode * inode,loff_t pos,unsigned len,unsigned * copied,struct ocfs2_dinode * di,struct ocfs2_write_ctxt * wc)1951 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1952 				   unsigned len, unsigned *copied,
1953 				   struct ocfs2_dinode *di,
1954 				   struct ocfs2_write_ctxt *wc)
1955 {
1956 	void *kaddr;
1957 
1958 	if (unlikely(*copied < len)) {
1959 		if (!PageUptodate(wc->w_target_page)) {
1960 			*copied = 0;
1961 			return;
1962 		}
1963 	}
1964 
1965 	kaddr = kmap_atomic(wc->w_target_page);
1966 	memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1967 	kunmap_atomic(kaddr);
1968 
1969 	trace_ocfs2_write_end_inline(
1970 	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
1971 	     (unsigned long long)pos, *copied,
1972 	     le16_to_cpu(di->id2.i_data.id_count),
1973 	     le16_to_cpu(di->i_dyn_features));
1974 }
1975 
ocfs2_write_end_nolock(struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,void * fsdata)1976 int ocfs2_write_end_nolock(struct address_space *mapping,
1977 			   loff_t pos, unsigned len, unsigned copied, void *fsdata)
1978 {
1979 	int i, ret;
1980 	unsigned from, to, start = pos & (PAGE_SIZE - 1);
1981 	struct inode *inode = mapping->host;
1982 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1983 	struct ocfs2_write_ctxt *wc = fsdata;
1984 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1985 	handle_t *handle = wc->w_handle;
1986 	struct page *tmppage;
1987 
1988 	BUG_ON(!list_empty(&wc->w_unwritten_list));
1989 
1990 	if (handle) {
1991 		ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode),
1992 				wc->w_di_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1993 		if (ret) {
1994 			copied = ret;
1995 			mlog_errno(ret);
1996 			goto out;
1997 		}
1998 	}
1999 
2000 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
2001 		ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
2002 		goto out_write_size;
2003 	}
2004 
2005 	if (unlikely(copied < len) && wc->w_target_page) {
2006 		loff_t new_isize;
2007 
2008 		if (!PageUptodate(wc->w_target_page))
2009 			copied = 0;
2010 
2011 		new_isize = max_t(loff_t, i_size_read(inode), pos + copied);
2012 		if (new_isize > page_offset(wc->w_target_page))
2013 			ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
2014 					       start+len);
2015 		else {
2016 			/*
2017 			 * When page is fully beyond new isize (data copy
2018 			 * failed), do not bother zeroing the page. Invalidate
2019 			 * it instead so that writeback does not get confused
2020 			 * put page & buffer dirty bits into inconsistent
2021 			 * state.
2022 			 */
2023 			block_invalidatepage(wc->w_target_page, 0, PAGE_SIZE);
2024 		}
2025 	}
2026 	if (wc->w_target_page)
2027 		flush_dcache_page(wc->w_target_page);
2028 
2029 	for(i = 0; i < wc->w_num_pages; i++) {
2030 		tmppage = wc->w_pages[i];
2031 
2032 		/* This is the direct io target page. */
2033 		if (tmppage == NULL)
2034 			continue;
2035 
2036 		if (tmppage == wc->w_target_page) {
2037 			from = wc->w_target_from;
2038 			to = wc->w_target_to;
2039 
2040 			BUG_ON(from > PAGE_SIZE ||
2041 			       to > PAGE_SIZE ||
2042 			       to < from);
2043 		} else {
2044 			/*
2045 			 * Pages adjacent to the target (if any) imply
2046 			 * a hole-filling write in which case we want
2047 			 * to flush their entire range.
2048 			 */
2049 			from = 0;
2050 			to = PAGE_SIZE;
2051 		}
2052 
2053 		if (page_has_buffers(tmppage)) {
2054 			if (handle && ocfs2_should_order_data(inode))
2055 				ocfs2_jbd2_file_inode(handle, inode);
2056 			block_commit_write(tmppage, from, to);
2057 		}
2058 	}
2059 
2060 out_write_size:
2061 	/* Direct io do not update i_size here. */
2062 	if (wc->w_type != OCFS2_WRITE_DIRECT) {
2063 		pos += copied;
2064 		if (pos > i_size_read(inode)) {
2065 			i_size_write(inode, pos);
2066 			mark_inode_dirty(inode);
2067 		}
2068 		inode->i_blocks = ocfs2_inode_sector_count(inode);
2069 		di->i_size = cpu_to_le64((u64)i_size_read(inode));
2070 		inode->i_mtime = inode->i_ctime = current_time(inode);
2071 		di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
2072 		di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
2073 		if (handle)
2074 			ocfs2_update_inode_fsync_trans(handle, inode, 1);
2075 	}
2076 	if (handle)
2077 		ocfs2_journal_dirty(handle, wc->w_di_bh);
2078 
2079 out:
2080 	/* unlock pages before dealloc since it needs acquiring j_trans_barrier
2081 	 * lock, or it will cause a deadlock since journal commit threads holds
2082 	 * this lock and will ask for the page lock when flushing the data.
2083 	 * put it here to preserve the unlock order.
2084 	 */
2085 	ocfs2_unlock_pages(wc);
2086 
2087 	if (handle)
2088 		ocfs2_commit_trans(osb, handle);
2089 
2090 	ocfs2_run_deallocs(osb, &wc->w_dealloc);
2091 
2092 	brelse(wc->w_di_bh);
2093 	kfree(wc);
2094 
2095 	return copied;
2096 }
2097 
ocfs2_write_end(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct page * page,void * fsdata)2098 static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2099 			   loff_t pos, unsigned len, unsigned copied,
2100 			   struct page *page, void *fsdata)
2101 {
2102 	int ret;
2103 	struct inode *inode = mapping->host;
2104 
2105 	ret = ocfs2_write_end_nolock(mapping, pos, len, copied, fsdata);
2106 
2107 	up_write(&OCFS2_I(inode)->ip_alloc_sem);
2108 	ocfs2_inode_unlock(inode, 1);
2109 
2110 	return ret;
2111 }
2112 
2113 struct ocfs2_dio_write_ctxt {
2114 	struct list_head	dw_zero_list;
2115 	unsigned		dw_zero_count;
2116 	int			dw_orphaned;
2117 	pid_t			dw_writer_pid;
2118 };
2119 
2120 static struct ocfs2_dio_write_ctxt *
ocfs2_dio_alloc_write_ctx(struct buffer_head * bh,int * alloc)2121 ocfs2_dio_alloc_write_ctx(struct buffer_head *bh, int *alloc)
2122 {
2123 	struct ocfs2_dio_write_ctxt *dwc = NULL;
2124 
2125 	if (bh->b_private)
2126 		return bh->b_private;
2127 
2128 	dwc = kmalloc(sizeof(struct ocfs2_dio_write_ctxt), GFP_NOFS);
2129 	if (dwc == NULL)
2130 		return NULL;
2131 	INIT_LIST_HEAD(&dwc->dw_zero_list);
2132 	dwc->dw_zero_count = 0;
2133 	dwc->dw_orphaned = 0;
2134 	dwc->dw_writer_pid = task_pid_nr(current);
2135 	bh->b_private = dwc;
2136 	*alloc = 1;
2137 
2138 	return dwc;
2139 }
2140 
ocfs2_dio_free_write_ctx(struct inode * inode,struct ocfs2_dio_write_ctxt * dwc)2141 static void ocfs2_dio_free_write_ctx(struct inode *inode,
2142 				     struct ocfs2_dio_write_ctxt *dwc)
2143 {
2144 	ocfs2_free_unwritten_list(inode, &dwc->dw_zero_list);
2145 	kfree(dwc);
2146 }
2147 
2148 /*
2149  * TODO: Make this into a generic get_blocks function.
2150  *
2151  * From do_direct_io in direct-io.c:
2152  *  "So what we do is to permit the ->get_blocks function to populate
2153  *   bh.b_size with the size of IO which is permitted at this offset and
2154  *   this i_blkbits."
2155  *
2156  * This function is called directly from get_more_blocks in direct-io.c.
2157  *
2158  * called like this: dio->get_blocks(dio->inode, fs_startblk,
2159  * 					fs_count, map_bh, dio->rw == WRITE);
2160  */
ocfs2_dio_wr_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)2161 static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock,
2162 			       struct buffer_head *bh_result, int create)
2163 {
2164 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2165 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2166 	struct ocfs2_write_ctxt *wc;
2167 	struct ocfs2_write_cluster_desc *desc = NULL;
2168 	struct ocfs2_dio_write_ctxt *dwc = NULL;
2169 	struct buffer_head *di_bh = NULL;
2170 	u64 p_blkno;
2171 	unsigned int i_blkbits = inode->i_sb->s_blocksize_bits;
2172 	loff_t pos = iblock << i_blkbits;
2173 	sector_t endblk = (i_size_read(inode) - 1) >> i_blkbits;
2174 	unsigned len, total_len = bh_result->b_size;
2175 	int ret = 0, first_get_block = 0;
2176 
2177 	len = osb->s_clustersize - (pos & (osb->s_clustersize - 1));
2178 	len = min(total_len, len);
2179 
2180 	/*
2181 	 * bh_result->b_size is count in get_more_blocks according to write
2182 	 * "pos" and "end", we need map twice to return different buffer state:
2183 	 * 1. area in file size, not set NEW;
2184 	 * 2. area out file size, set  NEW.
2185 	 *
2186 	 *		   iblock    endblk
2187 	 * |--------|---------|---------|---------
2188 	 * |<-------area in file------->|
2189 	 */
2190 
2191 	if ((iblock <= endblk) &&
2192 	    ((iblock + ((len - 1) >> i_blkbits)) > endblk))
2193 		len = (endblk - iblock + 1) << i_blkbits;
2194 
2195 	mlog(0, "get block of %lu at %llu:%u req %u\n",
2196 			inode->i_ino, pos, len, total_len);
2197 
2198 	/*
2199 	 * Because we need to change file size in ocfs2_dio_end_io_write(), or
2200 	 * we may need to add it to orphan dir. So can not fall to fast path
2201 	 * while file size will be changed.
2202 	 */
2203 	if (pos + total_len <= i_size_read(inode)) {
2204 
2205 		/* This is the fast path for re-write. */
2206 		ret = ocfs2_lock_get_block(inode, iblock, bh_result, create);
2207 		if (buffer_mapped(bh_result) &&
2208 		    !buffer_new(bh_result) &&
2209 		    ret == 0)
2210 			goto out;
2211 
2212 		/* Clear state set by ocfs2_get_block. */
2213 		bh_result->b_state = 0;
2214 	}
2215 
2216 	dwc = ocfs2_dio_alloc_write_ctx(bh_result, &first_get_block);
2217 	if (unlikely(dwc == NULL)) {
2218 		ret = -ENOMEM;
2219 		mlog_errno(ret);
2220 		goto out;
2221 	}
2222 
2223 	if (ocfs2_clusters_for_bytes(inode->i_sb, pos + total_len) >
2224 	    ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode)) &&
2225 	    !dwc->dw_orphaned) {
2226 		/*
2227 		 * when we are going to alloc extents beyond file size, add the
2228 		 * inode to orphan dir, so we can recall those spaces when
2229 		 * system crashed during write.
2230 		 */
2231 		ret = ocfs2_add_inode_to_orphan(osb, inode);
2232 		if (ret < 0) {
2233 			mlog_errno(ret);
2234 			goto out;
2235 		}
2236 		dwc->dw_orphaned = 1;
2237 	}
2238 
2239 	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2240 	if (ret) {
2241 		mlog_errno(ret);
2242 		goto out;
2243 	}
2244 
2245 	down_write(&oi->ip_alloc_sem);
2246 
2247 	if (first_get_block) {
2248 		if (ocfs2_sparse_alloc(osb))
2249 			ret = ocfs2_zero_tail(inode, di_bh, pos);
2250 		else
2251 			ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos,
2252 							   total_len, NULL);
2253 		if (ret < 0) {
2254 			mlog_errno(ret);
2255 			goto unlock;
2256 		}
2257 	}
2258 
2259 	ret = ocfs2_write_begin_nolock(inode->i_mapping, pos, len,
2260 				       OCFS2_WRITE_DIRECT, NULL,
2261 				       (void **)&wc, di_bh, NULL);
2262 	if (ret) {
2263 		mlog_errno(ret);
2264 		goto unlock;
2265 	}
2266 
2267 	desc = &wc->w_desc[0];
2268 
2269 	p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, desc->c_phys);
2270 	BUG_ON(p_blkno == 0);
2271 	p_blkno += iblock & (u64)(ocfs2_clusters_to_blocks(inode->i_sb, 1) - 1);
2272 
2273 	map_bh(bh_result, inode->i_sb, p_blkno);
2274 	bh_result->b_size = len;
2275 	if (desc->c_needs_zero)
2276 		set_buffer_new(bh_result);
2277 
2278 	if (iblock > endblk)
2279 		set_buffer_new(bh_result);
2280 
2281 	/* May sleep in end_io. It should not happen in a irq context. So defer
2282 	 * it to dio work queue. */
2283 	set_buffer_defer_completion(bh_result);
2284 
2285 	if (!list_empty(&wc->w_unwritten_list)) {
2286 		struct ocfs2_unwritten_extent *ue = NULL;
2287 
2288 		ue = list_first_entry(&wc->w_unwritten_list,
2289 				      struct ocfs2_unwritten_extent,
2290 				      ue_node);
2291 		BUG_ON(ue->ue_cpos != desc->c_cpos);
2292 		/* The physical address may be 0, fill it. */
2293 		ue->ue_phys = desc->c_phys;
2294 
2295 		list_splice_tail_init(&wc->w_unwritten_list, &dwc->dw_zero_list);
2296 		dwc->dw_zero_count += wc->w_unwritten_count;
2297 	}
2298 
2299 	ret = ocfs2_write_end_nolock(inode->i_mapping, pos, len, len, wc);
2300 	BUG_ON(ret != len);
2301 	ret = 0;
2302 unlock:
2303 	up_write(&oi->ip_alloc_sem);
2304 	ocfs2_inode_unlock(inode, 1);
2305 	brelse(di_bh);
2306 out:
2307 	if (ret < 0)
2308 		ret = -EIO;
2309 	return ret;
2310 }
2311 
ocfs2_dio_end_io_write(struct inode * inode,struct ocfs2_dio_write_ctxt * dwc,loff_t offset,ssize_t bytes)2312 static int ocfs2_dio_end_io_write(struct inode *inode,
2313 				  struct ocfs2_dio_write_ctxt *dwc,
2314 				  loff_t offset,
2315 				  ssize_t bytes)
2316 {
2317 	struct ocfs2_cached_dealloc_ctxt dealloc;
2318 	struct ocfs2_extent_tree et;
2319 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2320 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
2321 	struct ocfs2_unwritten_extent *ue = NULL;
2322 	struct buffer_head *di_bh = NULL;
2323 	struct ocfs2_dinode *di;
2324 	struct ocfs2_alloc_context *data_ac = NULL;
2325 	struct ocfs2_alloc_context *meta_ac = NULL;
2326 	handle_t *handle = NULL;
2327 	loff_t end = offset + bytes;
2328 	int ret = 0, credits = 0;
2329 
2330 	ocfs2_init_dealloc_ctxt(&dealloc);
2331 
2332 	/* We do clear unwritten, delete orphan, change i_size here. If neither
2333 	 * of these happen, we can skip all this. */
2334 	if (list_empty(&dwc->dw_zero_list) &&
2335 	    end <= i_size_read(inode) &&
2336 	    !dwc->dw_orphaned)
2337 		goto out;
2338 
2339 	ret = ocfs2_inode_lock(inode, &di_bh, 1);
2340 	if (ret < 0) {
2341 		mlog_errno(ret);
2342 		goto out;
2343 	}
2344 
2345 	down_write(&oi->ip_alloc_sem);
2346 
2347 	/* Delete orphan before acquire i_mutex. */
2348 	if (dwc->dw_orphaned) {
2349 		BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
2350 
2351 		end = end > i_size_read(inode) ? end : 0;
2352 
2353 		ret = ocfs2_del_inode_from_orphan(osb, inode, di_bh,
2354 				!!end, end);
2355 		if (ret < 0)
2356 			mlog_errno(ret);
2357 	}
2358 
2359 	di = (struct ocfs2_dinode *)di_bh->b_data;
2360 
2361 	ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
2362 
2363 	/* Attach dealloc with extent tree in case that we may reuse extents
2364 	 * which are already unlinked from current extent tree due to extent
2365 	 * rotation and merging.
2366 	 */
2367 	et.et_dealloc = &dealloc;
2368 
2369 	ret = ocfs2_lock_allocators(inode, &et, 0, dwc->dw_zero_count*2,
2370 				    &data_ac, &meta_ac);
2371 	if (ret) {
2372 		mlog_errno(ret);
2373 		goto unlock;
2374 	}
2375 
2376 	credits = ocfs2_calc_extend_credits(inode->i_sb, &di->id2.i_list);
2377 
2378 	handle = ocfs2_start_trans(osb, credits);
2379 	if (IS_ERR(handle)) {
2380 		ret = PTR_ERR(handle);
2381 		mlog_errno(ret);
2382 		goto unlock;
2383 	}
2384 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
2385 				      OCFS2_JOURNAL_ACCESS_WRITE);
2386 	if (ret) {
2387 		mlog_errno(ret);
2388 		goto commit;
2389 	}
2390 
2391 	list_for_each_entry(ue, &dwc->dw_zero_list, ue_node) {
2392 		ret = ocfs2_mark_extent_written(inode, &et, handle,
2393 						ue->ue_cpos, 1,
2394 						ue->ue_phys,
2395 						meta_ac, &dealloc);
2396 		if (ret < 0) {
2397 			mlog_errno(ret);
2398 			break;
2399 		}
2400 	}
2401 
2402 	if (end > i_size_read(inode)) {
2403 		ret = ocfs2_set_inode_size(handle, inode, di_bh, end);
2404 		if (ret < 0)
2405 			mlog_errno(ret);
2406 	}
2407 commit:
2408 	ocfs2_commit_trans(osb, handle);
2409 unlock:
2410 	up_write(&oi->ip_alloc_sem);
2411 	ocfs2_inode_unlock(inode, 1);
2412 	brelse(di_bh);
2413 out:
2414 	if (data_ac)
2415 		ocfs2_free_alloc_context(data_ac);
2416 	if (meta_ac)
2417 		ocfs2_free_alloc_context(meta_ac);
2418 	ocfs2_run_deallocs(osb, &dealloc);
2419 	ocfs2_dio_free_write_ctx(inode, dwc);
2420 
2421 	return ret;
2422 }
2423 
2424 /*
2425  * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
2426  * particularly interested in the aio/dio case.  We use the rw_lock DLM lock
2427  * to protect io on one node from truncation on another.
2428  */
ocfs2_dio_end_io(struct kiocb * iocb,loff_t offset,ssize_t bytes,void * private)2429 static int ocfs2_dio_end_io(struct kiocb *iocb,
2430 			    loff_t offset,
2431 			    ssize_t bytes,
2432 			    void *private)
2433 {
2434 	struct inode *inode = file_inode(iocb->ki_filp);
2435 	int level;
2436 	int ret = 0;
2437 
2438 	/* this io's submitter should not have unlocked this before we could */
2439 	BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
2440 
2441 	if (bytes <= 0)
2442 		mlog_ratelimited(ML_ERROR, "Direct IO failed, bytes = %lld",
2443 				 (long long)bytes);
2444 	if (private) {
2445 		if (bytes > 0)
2446 			ret = ocfs2_dio_end_io_write(inode, private, offset,
2447 						     bytes);
2448 		else
2449 			ocfs2_dio_free_write_ctx(inode, private);
2450 	}
2451 
2452 	ocfs2_iocb_clear_rw_locked(iocb);
2453 
2454 	level = ocfs2_iocb_rw_locked_level(iocb);
2455 	ocfs2_rw_unlock(inode, level);
2456 	return ret;
2457 }
2458 
ocfs2_direct_IO(struct kiocb * iocb,struct iov_iter * iter)2459 static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
2460 {
2461 	struct file *file = iocb->ki_filp;
2462 	struct inode *inode = file->f_mapping->host;
2463 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2464 	get_block_t *get_block;
2465 
2466 	/*
2467 	 * Fallback to buffered I/O if we see an inode without
2468 	 * extents.
2469 	 */
2470 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
2471 		return 0;
2472 
2473 	/* Fallback to buffered I/O if we do not support append dio. */
2474 	if (iocb->ki_pos + iter->count > i_size_read(inode) &&
2475 	    !ocfs2_supports_append_dio(osb))
2476 		return 0;
2477 
2478 	if (iov_iter_rw(iter) == READ)
2479 		get_block = ocfs2_lock_get_block;
2480 	else
2481 		get_block = ocfs2_dio_wr_get_block;
2482 
2483 	return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
2484 				    iter, get_block,
2485 				    ocfs2_dio_end_io, NULL, 0);
2486 }
2487 
2488 const struct address_space_operations ocfs2_aops = {
2489 	.readpage		= ocfs2_readpage,
2490 	.readpages		= ocfs2_readpages,
2491 	.writepage		= ocfs2_writepage,
2492 	.write_begin		= ocfs2_write_begin,
2493 	.write_end		= ocfs2_write_end,
2494 	.bmap			= ocfs2_bmap,
2495 	.direct_IO		= ocfs2_direct_IO,
2496 	.invalidatepage		= block_invalidatepage,
2497 	.releasepage		= ocfs2_releasepage,
2498 	.migratepage		= buffer_migrate_page,
2499 	.is_partially_uptodate	= block_is_partially_uptodate,
2500 	.error_remove_page	= generic_error_remove_page,
2501 };
2502