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1 /*
2  * Copyright (C) 2005, 2006
3  * Avishay Traeger (avishay@gmail.com)
4  * Copyright (C) 2008, 2009
5  * Boaz Harrosh <bharrosh@panasas.com>
6  *
7  * Copyrights for code taken from ext2:
8  *     Copyright (C) 1992, 1993, 1994, 1995
9  *     Remy Card (card@masi.ibp.fr)
10  *     Laboratoire MASI - Institut Blaise Pascal
11  *     Universite Pierre et Marie Curie (Paris VI)
12  *     from
13  *     linux/fs/minix/inode.c
14  *     Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  * This file is part of exofs.
17  *
18  * exofs is free software; you can redistribute it and/or modify
19  * it under the terms of the GNU General Public License as published by
20  * the Free Software Foundation.  Since it is based on ext2, and the only
21  * valid version of GPL for the Linux kernel is version 2, the only valid
22  * version of GPL for exofs is version 2.
23  *
24  * exofs is distributed in the hope that it will be useful,
25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
27  * GNU General Public License for more details.
28  *
29  * You should have received a copy of the GNU General Public License
30  * along with exofs; if not, write to the Free Software
31  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
32  */
33 
34 #include <linux/slab.h>
35 
36 #include "exofs.h"
37 
38 #define EXOFS_DBGMSG2(M...) do {} while (0)
39 
40 enum {MAX_PAGES_KMALLOC = PAGE_SIZE / sizeof(struct page *), };
41 
exofs_max_io_pages(struct ore_layout * layout,unsigned expected_pages)42 unsigned exofs_max_io_pages(struct ore_layout *layout,
43 			    unsigned expected_pages)
44 {
45 	unsigned pages = min_t(unsigned, expected_pages, MAX_PAGES_KMALLOC);
46 
47 	/* TODO: easily support bio chaining */
48 	pages =  min_t(unsigned, pages, layout->max_io_length / PAGE_SIZE);
49 	return pages;
50 }
51 
52 struct page_collect {
53 	struct exofs_sb_info *sbi;
54 	struct inode *inode;
55 	unsigned expected_pages;
56 	struct ore_io_state *ios;
57 
58 	struct page **pages;
59 	unsigned alloc_pages;
60 	unsigned nr_pages;
61 	unsigned long length;
62 	loff_t pg_first; /* keep 64bit also in 32-arches */
63 	bool read_4_write; /* This means two things: that the read is sync
64 			    * And the pages should not be unlocked.
65 			    */
66 	struct page *that_locked_page;
67 };
68 
_pcol_init(struct page_collect * pcol,unsigned expected_pages,struct inode * inode)69 static void _pcol_init(struct page_collect *pcol, unsigned expected_pages,
70 		       struct inode *inode)
71 {
72 	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
73 
74 	pcol->sbi = sbi;
75 	pcol->inode = inode;
76 	pcol->expected_pages = expected_pages;
77 
78 	pcol->ios = NULL;
79 	pcol->pages = NULL;
80 	pcol->alloc_pages = 0;
81 	pcol->nr_pages = 0;
82 	pcol->length = 0;
83 	pcol->pg_first = -1;
84 	pcol->read_4_write = false;
85 	pcol->that_locked_page = NULL;
86 }
87 
_pcol_reset(struct page_collect * pcol)88 static void _pcol_reset(struct page_collect *pcol)
89 {
90 	pcol->expected_pages -= min(pcol->nr_pages, pcol->expected_pages);
91 
92 	pcol->pages = NULL;
93 	pcol->alloc_pages = 0;
94 	pcol->nr_pages = 0;
95 	pcol->length = 0;
96 	pcol->pg_first = -1;
97 	pcol->ios = NULL;
98 	pcol->that_locked_page = NULL;
99 
100 	/* this is probably the end of the loop but in writes
101 	 * it might not end here. don't be left with nothing
102 	 */
103 	if (!pcol->expected_pages)
104 		pcol->expected_pages = MAX_PAGES_KMALLOC;
105 }
106 
pcol_try_alloc(struct page_collect * pcol)107 static int pcol_try_alloc(struct page_collect *pcol)
108 {
109 	unsigned pages;
110 
111 	/* TODO: easily support bio chaining */
112 	pages =  exofs_max_io_pages(&pcol->sbi->layout, pcol->expected_pages);
113 
114 	for (; pages; pages >>= 1) {
115 		pcol->pages = kmalloc(pages * sizeof(struct page *),
116 				      GFP_KERNEL);
117 		if (likely(pcol->pages)) {
118 			pcol->alloc_pages = pages;
119 			return 0;
120 		}
121 	}
122 
123 	EXOFS_ERR("Failed to kmalloc expected_pages=%u\n",
124 		  pcol->expected_pages);
125 	return -ENOMEM;
126 }
127 
pcol_free(struct page_collect * pcol)128 static void pcol_free(struct page_collect *pcol)
129 {
130 	kfree(pcol->pages);
131 	pcol->pages = NULL;
132 
133 	if (pcol->ios) {
134 		ore_put_io_state(pcol->ios);
135 		pcol->ios = NULL;
136 	}
137 }
138 
pcol_add_page(struct page_collect * pcol,struct page * page,unsigned len)139 static int pcol_add_page(struct page_collect *pcol, struct page *page,
140 			 unsigned len)
141 {
142 	if (unlikely(pcol->nr_pages >= pcol->alloc_pages))
143 		return -ENOMEM;
144 
145 	pcol->pages[pcol->nr_pages++] = page;
146 	pcol->length += len;
147 	return 0;
148 }
149 
150 enum {PAGE_WAS_NOT_IN_IO = 17};
update_read_page(struct page * page,int ret)151 static int update_read_page(struct page *page, int ret)
152 {
153 	switch (ret) {
154 	case 0:
155 		/* Everything is OK */
156 		SetPageUptodate(page);
157 		if (PageError(page))
158 			ClearPageError(page);
159 		break;
160 	case -EFAULT:
161 		/* In this case we were trying to read something that wasn't on
162 		 * disk yet - return a page full of zeroes.  This should be OK,
163 		 * because the object should be empty (if there was a write
164 		 * before this read, the read would be waiting with the page
165 		 * locked */
166 		clear_highpage(page);
167 
168 		SetPageUptodate(page);
169 		if (PageError(page))
170 			ClearPageError(page);
171 		EXOFS_DBGMSG("recovered read error\n");
172 		/* fall through */
173 	case PAGE_WAS_NOT_IN_IO:
174 		ret = 0; /* recovered error */
175 		break;
176 	default:
177 		SetPageError(page);
178 	}
179 	return ret;
180 }
181 
update_write_page(struct page * page,int ret)182 static void update_write_page(struct page *page, int ret)
183 {
184 	if (unlikely(ret == PAGE_WAS_NOT_IN_IO))
185 		return; /* don't pass start don't collect $200 */
186 
187 	if (ret) {
188 		mapping_set_error(page->mapping, ret);
189 		SetPageError(page);
190 	}
191 	end_page_writeback(page);
192 }
193 
194 /* Called at the end of reads, to optionally unlock pages and update their
195  * status.
196  */
__readpages_done(struct page_collect * pcol)197 static int __readpages_done(struct page_collect *pcol)
198 {
199 	int i;
200 	u64 good_bytes;
201 	u64 length = 0;
202 	int ret = ore_check_io(pcol->ios, NULL);
203 
204 	if (likely(!ret)) {
205 		good_bytes = pcol->length;
206 		ret = PAGE_WAS_NOT_IN_IO;
207 	} else {
208 		good_bytes = 0;
209 	}
210 
211 	EXOFS_DBGMSG2("readpages_done(0x%lx) good_bytes=0x%llx"
212 		     " length=0x%lx nr_pages=%u\n",
213 		     pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
214 		     pcol->nr_pages);
215 
216 	for (i = 0; i < pcol->nr_pages; i++) {
217 		struct page *page = pcol->pages[i];
218 		struct inode *inode = page->mapping->host;
219 		int page_stat;
220 
221 		if (inode != pcol->inode)
222 			continue; /* osd might add more pages at end */
223 
224 		if (likely(length < good_bytes))
225 			page_stat = 0;
226 		else
227 			page_stat = ret;
228 
229 		EXOFS_DBGMSG2("    readpages_done(0x%lx, 0x%lx) %s\n",
230 			  inode->i_ino, page->index,
231 			  page_stat ? "bad_bytes" : "good_bytes");
232 
233 		ret = update_read_page(page, page_stat);
234 		if (!pcol->read_4_write)
235 			unlock_page(page);
236 		length += PAGE_SIZE;
237 	}
238 
239 	pcol_free(pcol);
240 	EXOFS_DBGMSG2("readpages_done END\n");
241 	return ret;
242 }
243 
244 /* callback of async reads */
readpages_done(struct ore_io_state * ios,void * p)245 static void readpages_done(struct ore_io_state *ios, void *p)
246 {
247 	struct page_collect *pcol = p;
248 
249 	__readpages_done(pcol);
250 	atomic_dec(&pcol->sbi->s_curr_pending);
251 	kfree(pcol);
252 }
253 
_unlock_pcol_pages(struct page_collect * pcol,int ret,int rw)254 static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
255 {
256 	int i;
257 
258 	for (i = 0; i < pcol->nr_pages; i++) {
259 		struct page *page = pcol->pages[i];
260 
261 		if (rw == READ)
262 			update_read_page(page, ret);
263 		else
264 			update_write_page(page, ret);
265 
266 		unlock_page(page);
267 	}
268 }
269 
_maybe_not_all_in_one_io(struct ore_io_state * ios,struct page_collect * pcol_src,struct page_collect * pcol)270 static int _maybe_not_all_in_one_io(struct ore_io_state *ios,
271 	struct page_collect *pcol_src, struct page_collect *pcol)
272 {
273 	/* length was wrong or offset was not page aligned */
274 	BUG_ON(pcol_src->nr_pages < ios->nr_pages);
275 
276 	if (pcol_src->nr_pages > ios->nr_pages) {
277 		struct page **src_page;
278 		unsigned pages_less = pcol_src->nr_pages - ios->nr_pages;
279 		unsigned long len_less = pcol_src->length - ios->length;
280 		unsigned i;
281 		int ret;
282 
283 		/* This IO was trimmed */
284 		pcol_src->nr_pages = ios->nr_pages;
285 		pcol_src->length = ios->length;
286 
287 		/* Left over pages are passed to the next io */
288 		pcol->expected_pages += pages_less;
289 		pcol->nr_pages = pages_less;
290 		pcol->length = len_less;
291 		src_page = pcol_src->pages + pcol_src->nr_pages;
292 		pcol->pg_first = (*src_page)->index;
293 
294 		ret = pcol_try_alloc(pcol);
295 		if (unlikely(ret))
296 			return ret;
297 
298 		for (i = 0; i < pages_less; ++i)
299 			pcol->pages[i] = *src_page++;
300 
301 		EXOFS_DBGMSG("Length was adjusted nr_pages=0x%x "
302 			"pages_less=0x%x expected_pages=0x%x "
303 			"next_offset=0x%llx next_len=0x%lx\n",
304 			pcol_src->nr_pages, pages_less, pcol->expected_pages,
305 			pcol->pg_first * PAGE_SIZE, pcol->length);
306 	}
307 	return 0;
308 }
309 
read_exec(struct page_collect * pcol)310 static int read_exec(struct page_collect *pcol)
311 {
312 	struct exofs_i_info *oi = exofs_i(pcol->inode);
313 	struct ore_io_state *ios;
314 	struct page_collect *pcol_copy = NULL;
315 	int ret;
316 
317 	if (!pcol->pages)
318 		return 0;
319 
320 	if (!pcol->ios) {
321 		int ret = ore_get_rw_state(&pcol->sbi->layout, &oi->oc, true,
322 					     pcol->pg_first << PAGE_CACHE_SHIFT,
323 					     pcol->length, &pcol->ios);
324 
325 		if (ret)
326 			return ret;
327 	}
328 
329 	ios = pcol->ios;
330 	ios->pages = pcol->pages;
331 
332 	if (pcol->read_4_write) {
333 		ore_read(pcol->ios);
334 		return __readpages_done(pcol);
335 	}
336 
337 	pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
338 	if (!pcol_copy) {
339 		ret = -ENOMEM;
340 		goto err;
341 	}
342 
343 	*pcol_copy = *pcol;
344 	ios->done = readpages_done;
345 	ios->private = pcol_copy;
346 
347 	/* pages ownership was passed to pcol_copy */
348 	_pcol_reset(pcol);
349 
350 	ret = _maybe_not_all_in_one_io(ios, pcol_copy, pcol);
351 	if (unlikely(ret))
352 		goto err;
353 
354 	EXOFS_DBGMSG2("read_exec(0x%lx) offset=0x%llx length=0x%llx\n",
355 		pcol->inode->i_ino, _LLU(ios->offset), _LLU(ios->length));
356 
357 	ret = ore_read(ios);
358 	if (unlikely(ret))
359 		goto err;
360 
361 	atomic_inc(&pcol->sbi->s_curr_pending);
362 
363 	return 0;
364 
365 err:
366 	if (!pcol->read_4_write)
367 		_unlock_pcol_pages(pcol, ret, READ);
368 
369 	pcol_free(pcol);
370 
371 	kfree(pcol_copy);
372 	return ret;
373 }
374 
375 /* readpage_strip is called either directly from readpage() or by the VFS from
376  * within read_cache_pages(), to add one more page to be read. It will try to
377  * collect as many contiguous pages as posible. If a discontinuity is
378  * encountered, or it runs out of resources, it will submit the previous segment
379  * and will start a new collection. Eventually caller must submit the last
380  * segment if present.
381  */
readpage_strip(void * data,struct page * page)382 static int readpage_strip(void *data, struct page *page)
383 {
384 	struct page_collect *pcol = data;
385 	struct inode *inode = pcol->inode;
386 	struct exofs_i_info *oi = exofs_i(inode);
387 	loff_t i_size = i_size_read(inode);
388 	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
389 	size_t len;
390 	int ret;
391 
392 	/* FIXME: Just for debugging, will be removed */
393 	if (PageUptodate(page))
394 		EXOFS_ERR("PageUptodate(0x%lx, 0x%lx)\n", pcol->inode->i_ino,
395 			  page->index);
396 
397 	pcol->that_locked_page = page;
398 
399 	if (page->index < end_index)
400 		len = PAGE_CACHE_SIZE;
401 	else if (page->index == end_index)
402 		len = i_size & ~PAGE_CACHE_MASK;
403 	else
404 		len = 0;
405 
406 	if (!len || !obj_created(oi)) {
407 		/* this will be out of bounds, or doesn't exist yet.
408 		 * Current page is cleared and the request is split
409 		 */
410 		clear_highpage(page);
411 
412 		SetPageUptodate(page);
413 		if (PageError(page))
414 			ClearPageError(page);
415 
416 		if (!pcol->read_4_write)
417 			unlock_page(page);
418 		EXOFS_DBGMSG("readpage_strip(0x%lx) empty page len=%zx "
419 			     "read_4_write=%d index=0x%lx end_index=0x%lx "
420 			     "splitting\n", inode->i_ino, len,
421 			     pcol->read_4_write, page->index, end_index);
422 
423 		return read_exec(pcol);
424 	}
425 
426 try_again:
427 
428 	if (unlikely(pcol->pg_first == -1)) {
429 		pcol->pg_first = page->index;
430 	} else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
431 		   page->index)) {
432 		/* Discontinuity detected, split the request */
433 		ret = read_exec(pcol);
434 		if (unlikely(ret))
435 			goto fail;
436 		goto try_again;
437 	}
438 
439 	if (!pcol->pages) {
440 		ret = pcol_try_alloc(pcol);
441 		if (unlikely(ret))
442 			goto fail;
443 	}
444 
445 	if (len != PAGE_CACHE_SIZE)
446 		zero_user(page, len, PAGE_CACHE_SIZE - len);
447 
448 	EXOFS_DBGMSG2("    readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
449 		     inode->i_ino, page->index, len);
450 
451 	ret = pcol_add_page(pcol, page, len);
452 	if (ret) {
453 		EXOFS_DBGMSG2("Failed pcol_add_page pages[i]=%p "
454 			  "this_len=0x%zx nr_pages=%u length=0x%lx\n",
455 			  page, len, pcol->nr_pages, pcol->length);
456 
457 		/* split the request, and start again with current page */
458 		ret = read_exec(pcol);
459 		if (unlikely(ret))
460 			goto fail;
461 
462 		goto try_again;
463 	}
464 
465 	return 0;
466 
467 fail:
468 	/* SetPageError(page); ??? */
469 	unlock_page(page);
470 	return ret;
471 }
472 
exofs_readpages(struct file * file,struct address_space * mapping,struct list_head * pages,unsigned nr_pages)473 static int exofs_readpages(struct file *file, struct address_space *mapping,
474 			   struct list_head *pages, unsigned nr_pages)
475 {
476 	struct page_collect pcol;
477 	int ret;
478 
479 	_pcol_init(&pcol, nr_pages, mapping->host);
480 
481 	ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
482 	if (ret) {
483 		EXOFS_ERR("read_cache_pages => %d\n", ret);
484 		return ret;
485 	}
486 
487 	ret = read_exec(&pcol);
488 	if (unlikely(ret))
489 		return ret;
490 
491 	return read_exec(&pcol);
492 }
493 
_readpage(struct page * page,bool read_4_write)494 static int _readpage(struct page *page, bool read_4_write)
495 {
496 	struct page_collect pcol;
497 	int ret;
498 
499 	_pcol_init(&pcol, 1, page->mapping->host);
500 
501 	pcol.read_4_write = read_4_write;
502 	ret = readpage_strip(&pcol, page);
503 	if (ret) {
504 		EXOFS_ERR("_readpage => %d\n", ret);
505 		return ret;
506 	}
507 
508 	return read_exec(&pcol);
509 }
510 
511 /*
512  * We don't need the file
513  */
exofs_readpage(struct file * file,struct page * page)514 static int exofs_readpage(struct file *file, struct page *page)
515 {
516 	return _readpage(page, false);
517 }
518 
519 /* Callback for osd_write. All writes are asynchronous */
writepages_done(struct ore_io_state * ios,void * p)520 static void writepages_done(struct ore_io_state *ios, void *p)
521 {
522 	struct page_collect *pcol = p;
523 	int i;
524 	u64  good_bytes;
525 	u64  length = 0;
526 	int ret = ore_check_io(ios, NULL);
527 
528 	atomic_dec(&pcol->sbi->s_curr_pending);
529 
530 	if (likely(!ret)) {
531 		good_bytes = pcol->length;
532 		ret = PAGE_WAS_NOT_IN_IO;
533 	} else {
534 		good_bytes = 0;
535 	}
536 
537 	EXOFS_DBGMSG2("writepages_done(0x%lx) good_bytes=0x%llx"
538 		     " length=0x%lx nr_pages=%u\n",
539 		     pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
540 		     pcol->nr_pages);
541 
542 	for (i = 0; i < pcol->nr_pages; i++) {
543 		struct page *page = pcol->pages[i];
544 		struct inode *inode = page->mapping->host;
545 		int page_stat;
546 
547 		if (inode != pcol->inode)
548 			continue; /* osd might add more pages to a bio */
549 
550 		if (likely(length < good_bytes))
551 			page_stat = 0;
552 		else
553 			page_stat = ret;
554 
555 		update_write_page(page, page_stat);
556 		unlock_page(page);
557 		EXOFS_DBGMSG2("    writepages_done(0x%lx, 0x%lx) status=%d\n",
558 			     inode->i_ino, page->index, page_stat);
559 
560 		length += PAGE_SIZE;
561 	}
562 
563 	pcol_free(pcol);
564 	kfree(pcol);
565 	EXOFS_DBGMSG2("writepages_done END\n");
566 }
567 
__r4w_get_page(void * priv,u64 offset,bool * uptodate)568 static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
569 {
570 	struct page_collect *pcol = priv;
571 	pgoff_t index = offset / PAGE_SIZE;
572 
573 	if (!pcol->that_locked_page ||
574 	    (pcol->that_locked_page->index != index)) {
575 		struct page *page = find_get_page(pcol->inode->i_mapping, index);
576 
577 		if (!page) {
578 			page = find_or_create_page(pcol->inode->i_mapping,
579 						   index, GFP_NOFS);
580 			if (unlikely(!page)) {
581 				EXOFS_DBGMSG("grab_cache_page Failed "
582 					"index=0x%llx\n", _LLU(index));
583 				return NULL;
584 			}
585 			unlock_page(page);
586 		}
587 		if (PageDirty(page) || PageWriteback(page))
588 			*uptodate = true;
589 		else
590 			*uptodate = PageUptodate(page);
591 		EXOFS_DBGMSG("index=0x%lx uptodate=%d\n", index, *uptodate);
592 		return page;
593 	} else {
594 		EXOFS_DBGMSG("YES that_locked_page index=0x%lx\n",
595 			     pcol->that_locked_page->index);
596 		*uptodate = true;
597 		return pcol->that_locked_page;
598 	}
599 }
600 
__r4w_put_page(void * priv,struct page * page)601 static void __r4w_put_page(void *priv, struct page *page)
602 {
603 	struct page_collect *pcol = priv;
604 
605 	if (pcol->that_locked_page != page) {
606 		EXOFS_DBGMSG("index=0x%lx\n", page->index);
607 		page_cache_release(page);
608 		return;
609 	}
610 	EXOFS_DBGMSG("that_locked_page index=0x%lx\n", page->index);
611 }
612 
613 static const struct _ore_r4w_op _r4w_op = {
614 	.get_page = &__r4w_get_page,
615 	.put_page = &__r4w_put_page,
616 };
617 
write_exec(struct page_collect * pcol)618 static int write_exec(struct page_collect *pcol)
619 {
620 	struct exofs_i_info *oi = exofs_i(pcol->inode);
621 	struct ore_io_state *ios;
622 	struct page_collect *pcol_copy = NULL;
623 	int ret;
624 
625 	if (!pcol->pages)
626 		return 0;
627 
628 	BUG_ON(pcol->ios);
629 	ret = ore_get_rw_state(&pcol->sbi->layout, &oi->oc, false,
630 				 pcol->pg_first << PAGE_CACHE_SHIFT,
631 				 pcol->length, &pcol->ios);
632 	if (unlikely(ret))
633 		goto err;
634 
635 	pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
636 	if (!pcol_copy) {
637 		EXOFS_ERR("write_exec: Failed to kmalloc(pcol)\n");
638 		ret = -ENOMEM;
639 		goto err;
640 	}
641 
642 	*pcol_copy = *pcol;
643 
644 	ios = pcol->ios;
645 	ios->pages = pcol_copy->pages;
646 	ios->done = writepages_done;
647 	ios->r4w = &_r4w_op;
648 	ios->private = pcol_copy;
649 
650 	/* pages ownership was passed to pcol_copy */
651 	_pcol_reset(pcol);
652 
653 	ret = _maybe_not_all_in_one_io(ios, pcol_copy, pcol);
654 	if (unlikely(ret))
655 		goto err;
656 
657 	EXOFS_DBGMSG2("write_exec(0x%lx) offset=0x%llx length=0x%llx\n",
658 		pcol->inode->i_ino, _LLU(ios->offset), _LLU(ios->length));
659 
660 	ret = ore_write(ios);
661 	if (unlikely(ret)) {
662 		EXOFS_ERR("write_exec: ore_write() Failed\n");
663 		goto err;
664 	}
665 
666 	atomic_inc(&pcol->sbi->s_curr_pending);
667 	return 0;
668 
669 err:
670 	_unlock_pcol_pages(pcol, ret, WRITE);
671 	pcol_free(pcol);
672 	kfree(pcol_copy);
673 
674 	return ret;
675 }
676 
677 /* writepage_strip is called either directly from writepage() or by the VFS from
678  * within write_cache_pages(), to add one more page to be written to storage.
679  * It will try to collect as many contiguous pages as possible. If a
680  * discontinuity is encountered or it runs out of resources it will submit the
681  * previous segment and will start a new collection.
682  * Eventually caller must submit the last segment if present.
683  */
writepage_strip(struct page * page,struct writeback_control * wbc_unused,void * data)684 static int writepage_strip(struct page *page,
685 			   struct writeback_control *wbc_unused, void *data)
686 {
687 	struct page_collect *pcol = data;
688 	struct inode *inode = pcol->inode;
689 	struct exofs_i_info *oi = exofs_i(inode);
690 	loff_t i_size = i_size_read(inode);
691 	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
692 	size_t len;
693 	int ret;
694 
695 	BUG_ON(!PageLocked(page));
696 
697 	ret = wait_obj_created(oi);
698 	if (unlikely(ret))
699 		goto fail;
700 
701 	if (page->index < end_index)
702 		/* in this case, the page is within the limits of the file */
703 		len = PAGE_CACHE_SIZE;
704 	else {
705 		len = i_size & ~PAGE_CACHE_MASK;
706 
707 		if (page->index > end_index || !len) {
708 			/* in this case, the page is outside the limits
709 			 * (truncate in progress)
710 			 */
711 			ret = write_exec(pcol);
712 			if (unlikely(ret))
713 				goto fail;
714 			if (PageError(page))
715 				ClearPageError(page);
716 			unlock_page(page);
717 			EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) "
718 				     "outside the limits\n",
719 				     inode->i_ino, page->index);
720 			return 0;
721 		}
722 	}
723 
724 try_again:
725 
726 	if (unlikely(pcol->pg_first == -1)) {
727 		pcol->pg_first = page->index;
728 	} else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
729 		   page->index)) {
730 		/* Discontinuity detected, split the request */
731 		ret = write_exec(pcol);
732 		if (unlikely(ret))
733 			goto fail;
734 
735 		EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) Discontinuity\n",
736 			     inode->i_ino, page->index);
737 		goto try_again;
738 	}
739 
740 	if (!pcol->pages) {
741 		ret = pcol_try_alloc(pcol);
742 		if (unlikely(ret))
743 			goto fail;
744 	}
745 
746 	EXOFS_DBGMSG2("    writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
747 		     inode->i_ino, page->index, len);
748 
749 	ret = pcol_add_page(pcol, page, len);
750 	if (unlikely(ret)) {
751 		EXOFS_DBGMSG2("Failed pcol_add_page "
752 			     "nr_pages=%u total_length=0x%lx\n",
753 			     pcol->nr_pages, pcol->length);
754 
755 		/* split the request, next loop will start again */
756 		ret = write_exec(pcol);
757 		if (unlikely(ret)) {
758 			EXOFS_DBGMSG("write_exec failed => %d", ret);
759 			goto fail;
760 		}
761 
762 		goto try_again;
763 	}
764 
765 	BUG_ON(PageWriteback(page));
766 	set_page_writeback(page);
767 
768 	return 0;
769 
770 fail:
771 	EXOFS_DBGMSG("Error: writepage_strip(0x%lx, 0x%lx)=>%d\n",
772 		     inode->i_ino, page->index, ret);
773 	set_bit(AS_EIO, &page->mapping->flags);
774 	unlock_page(page);
775 	return ret;
776 }
777 
exofs_writepages(struct address_space * mapping,struct writeback_control * wbc)778 static int exofs_writepages(struct address_space *mapping,
779 		       struct writeback_control *wbc)
780 {
781 	struct page_collect pcol;
782 	long start, end, expected_pages;
783 	int ret;
784 
785 	start = wbc->range_start >> PAGE_CACHE_SHIFT;
786 	end = (wbc->range_end == LLONG_MAX) ?
787 			start + mapping->nrpages :
788 			wbc->range_end >> PAGE_CACHE_SHIFT;
789 
790 	if (start || end)
791 		expected_pages = end - start + 1;
792 	else
793 		expected_pages = mapping->nrpages;
794 
795 	if (expected_pages < 32L)
796 		expected_pages = 32L;
797 
798 	EXOFS_DBGMSG2("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx "
799 		     "nrpages=%lu start=0x%lx end=0x%lx expected_pages=%ld\n",
800 		     mapping->host->i_ino, wbc->range_start, wbc->range_end,
801 		     mapping->nrpages, start, end, expected_pages);
802 
803 	_pcol_init(&pcol, expected_pages, mapping->host);
804 
805 	ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
806 	if (unlikely(ret)) {
807 		EXOFS_ERR("write_cache_pages => %d\n", ret);
808 		return ret;
809 	}
810 
811 	ret = write_exec(&pcol);
812 	if (unlikely(ret))
813 		return ret;
814 
815 	if (wbc->sync_mode == WB_SYNC_ALL) {
816 		return write_exec(&pcol); /* pump the last reminder */
817 	} else if (pcol.nr_pages) {
818 		/* not SYNC let the reminder join the next writeout */
819 		unsigned i;
820 
821 		for (i = 0; i < pcol.nr_pages; i++) {
822 			struct page *page = pcol.pages[i];
823 
824 			end_page_writeback(page);
825 			set_page_dirty(page);
826 			unlock_page(page);
827 		}
828 	}
829 	return 0;
830 }
831 
832 /*
833 static int exofs_writepage(struct page *page, struct writeback_control *wbc)
834 {
835 	struct page_collect pcol;
836 	int ret;
837 
838 	_pcol_init(&pcol, 1, page->mapping->host);
839 
840 	ret = writepage_strip(page, NULL, &pcol);
841 	if (ret) {
842 		EXOFS_ERR("exofs_writepage => %d\n", ret);
843 		return ret;
844 	}
845 
846 	return write_exec(&pcol);
847 }
848 */
849 /* i_mutex held using inode->i_size directly */
_write_failed(struct inode * inode,loff_t to)850 static void _write_failed(struct inode *inode, loff_t to)
851 {
852 	if (to > inode->i_size)
853 		truncate_pagecache(inode, to, inode->i_size);
854 }
855 
exofs_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)856 int exofs_write_begin(struct file *file, struct address_space *mapping,
857 		loff_t pos, unsigned len, unsigned flags,
858 		struct page **pagep, void **fsdata)
859 {
860 	int ret = 0;
861 	struct page *page;
862 
863 	page = *pagep;
864 	if (page == NULL) {
865 		ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
866 					 fsdata);
867 		if (ret) {
868 			EXOFS_DBGMSG("simple_write_begin failed\n");
869 			goto out;
870 		}
871 
872 		page = *pagep;
873 	}
874 
875 	 /* read modify write */
876 	if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
877 		loff_t i_size = i_size_read(mapping->host);
878 		pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
879 		size_t rlen;
880 
881 		if (page->index < end_index)
882 			rlen = PAGE_CACHE_SIZE;
883 		else if (page->index == end_index)
884 			rlen = i_size & ~PAGE_CACHE_MASK;
885 		else
886 			rlen = 0;
887 
888 		if (!rlen) {
889 			clear_highpage(page);
890 			SetPageUptodate(page);
891 			goto out;
892 		}
893 
894 		ret = _readpage(page, true);
895 		if (ret) {
896 			/*SetPageError was done by _readpage. Is it ok?*/
897 			unlock_page(page);
898 			EXOFS_DBGMSG("__readpage failed\n");
899 		}
900 	}
901 out:
902 	if (unlikely(ret))
903 		_write_failed(mapping->host, pos + len);
904 
905 	return ret;
906 }
907 
exofs_write_begin_export(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)908 static int exofs_write_begin_export(struct file *file,
909 		struct address_space *mapping,
910 		loff_t pos, unsigned len, unsigned flags,
911 		struct page **pagep, void **fsdata)
912 {
913 	*pagep = NULL;
914 
915 	return exofs_write_begin(file, mapping, pos, len, flags, pagep,
916 					fsdata);
917 }
918 
exofs_write_end(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct page * page,void * fsdata)919 static int exofs_write_end(struct file *file, struct address_space *mapping,
920 			loff_t pos, unsigned len, unsigned copied,
921 			struct page *page, void *fsdata)
922 {
923 	struct inode *inode = mapping->host;
924 	/* According to comment in simple_write_end i_mutex is held */
925 	loff_t i_size = inode->i_size;
926 	int ret;
927 
928 	ret = simple_write_end(file, mapping,pos, len, copied, page, fsdata);
929 	if (unlikely(ret))
930 		_write_failed(inode, pos + len);
931 
932 	/* TODO: once simple_write_end marks inode dirty remove */
933 	if (i_size != inode->i_size)
934 		mark_inode_dirty(inode);
935 	return ret;
936 }
937 
exofs_releasepage(struct page * page,gfp_t gfp)938 static int exofs_releasepage(struct page *page, gfp_t gfp)
939 {
940 	EXOFS_DBGMSG("page 0x%lx\n", page->index);
941 	WARN_ON(1);
942 	return 0;
943 }
944 
exofs_invalidatepage(struct page * page,unsigned long offset)945 static void exofs_invalidatepage(struct page *page, unsigned long offset)
946 {
947 	EXOFS_DBGMSG("page 0x%lx offset 0x%lx\n", page->index, offset);
948 	WARN_ON(1);
949 }
950 
951 const struct address_space_operations exofs_aops = {
952 	.readpage	= exofs_readpage,
953 	.readpages	= exofs_readpages,
954 	.writepage	= NULL,
955 	.writepages	= exofs_writepages,
956 	.write_begin	= exofs_write_begin_export,
957 	.write_end	= exofs_write_end,
958 	.releasepage	= exofs_releasepage,
959 	.set_page_dirty	= __set_page_dirty_nobuffers,
960 	.invalidatepage = exofs_invalidatepage,
961 
962 	/* Not implemented Yet */
963 	.bmap		= NULL, /* TODO: use osd's OSD_ACT_READ_MAP */
964 	.direct_IO	= NULL, /* TODO: Should be trivial to do */
965 
966 	/* With these NULL has special meaning or default is not exported */
967 	.get_xip_mem	= NULL,
968 	.migratepage	= NULL,
969 	.launder_page	= NULL,
970 	.is_partially_uptodate = NULL,
971 	.error_remove_page = NULL,
972 };
973 
974 /******************************************************************************
975  * INODE OPERATIONS
976  *****************************************************************************/
977 
978 /*
979  * Test whether an inode is a fast symlink.
980  */
exofs_inode_is_fast_symlink(struct inode * inode)981 static inline int exofs_inode_is_fast_symlink(struct inode *inode)
982 {
983 	struct exofs_i_info *oi = exofs_i(inode);
984 
985 	return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
986 }
987 
_do_truncate(struct inode * inode,loff_t newsize)988 static int _do_truncate(struct inode *inode, loff_t newsize)
989 {
990 	struct exofs_i_info *oi = exofs_i(inode);
991 	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
992 	int ret;
993 
994 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
995 
996 	ret = ore_truncate(&sbi->layout, &oi->oc, (u64)newsize);
997 	if (likely(!ret))
998 		truncate_setsize(inode, newsize);
999 
1000 	EXOFS_DBGMSG("(0x%lx) size=0x%llx ret=>%d\n",
1001 		     inode->i_ino, newsize, ret);
1002 	return ret;
1003 }
1004 
1005 /*
1006  * Set inode attributes - update size attribute on OSD if needed,
1007  *                        otherwise just call generic functions.
1008  */
exofs_setattr(struct dentry * dentry,struct iattr * iattr)1009 int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
1010 {
1011 	struct inode *inode = dentry->d_inode;
1012 	int error;
1013 
1014 	/* if we are about to modify an object, and it hasn't been
1015 	 * created yet, wait
1016 	 */
1017 	error = wait_obj_created(exofs_i(inode));
1018 	if (unlikely(error))
1019 		return error;
1020 
1021 	error = inode_change_ok(inode, iattr);
1022 	if (unlikely(error))
1023 		return error;
1024 
1025 	if ((iattr->ia_valid & ATTR_SIZE) &&
1026 	    iattr->ia_size != i_size_read(inode)) {
1027 		error = _do_truncate(inode, iattr->ia_size);
1028 		if (unlikely(error))
1029 			return error;
1030 	}
1031 
1032 	setattr_copy(inode, iattr);
1033 	mark_inode_dirty(inode);
1034 	return 0;
1035 }
1036 
1037 static const struct osd_attr g_attr_inode_file_layout = ATTR_DEF(
1038 	EXOFS_APAGE_FS_DATA,
1039 	EXOFS_ATTR_INODE_FILE_LAYOUT,
1040 	0);
1041 static const struct osd_attr g_attr_inode_dir_layout = ATTR_DEF(
1042 	EXOFS_APAGE_FS_DATA,
1043 	EXOFS_ATTR_INODE_DIR_LAYOUT,
1044 	0);
1045 
1046 /*
1047  * Read the Linux inode info from the OSD, and return it as is. In exofs the
1048  * inode info is in an application specific page/attribute of the osd-object.
1049  */
exofs_get_inode(struct super_block * sb,struct exofs_i_info * oi,struct exofs_fcb * inode)1050 static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
1051 		    struct exofs_fcb *inode)
1052 {
1053 	struct exofs_sb_info *sbi = sb->s_fs_info;
1054 	struct osd_attr attrs[] = {
1055 		[0] = g_attr_inode_data,
1056 		[1] = g_attr_inode_file_layout,
1057 		[2] = g_attr_inode_dir_layout,
1058 	};
1059 	struct ore_io_state *ios;
1060 	struct exofs_on_disk_inode_layout *layout;
1061 	int ret;
1062 
1063 	ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
1064 	if (unlikely(ret)) {
1065 		EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
1066 		return ret;
1067 	}
1068 
1069 	attrs[1].len = exofs_on_disk_inode_layout_size(sbi->oc.numdevs);
1070 	attrs[2].len = exofs_on_disk_inode_layout_size(sbi->oc.numdevs);
1071 
1072 	ios->in_attr = attrs;
1073 	ios->in_attr_len = ARRAY_SIZE(attrs);
1074 
1075 	ret = ore_read(ios);
1076 	if (unlikely(ret)) {
1077 		EXOFS_ERR("object(0x%llx) corrupted, return empty file=>%d\n",
1078 			  _LLU(oi->one_comp.obj.id), ret);
1079 		memset(inode, 0, sizeof(*inode));
1080 		inode->i_mode = 0040000 | (0777 & ~022);
1081 		/* If object is lost on target we might as well enable it's
1082 		 * delete.
1083 		 */
1084 		if ((ret == -ENOENT) || (ret == -EINVAL))
1085 			ret = 0;
1086 		goto out;
1087 	}
1088 
1089 	ret = extract_attr_from_ios(ios, &attrs[0]);
1090 	if (ret) {
1091 		EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
1092 		goto out;
1093 	}
1094 	WARN_ON(attrs[0].len != EXOFS_INO_ATTR_SIZE);
1095 	memcpy(inode, attrs[0].val_ptr, EXOFS_INO_ATTR_SIZE);
1096 
1097 	ret = extract_attr_from_ios(ios, &attrs[1]);
1098 	if (ret) {
1099 		EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
1100 		goto out;
1101 	}
1102 	if (attrs[1].len) {
1103 		layout = attrs[1].val_ptr;
1104 		if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
1105 			EXOFS_ERR("%s: unsupported files layout %d\n",
1106 				__func__, layout->gen_func);
1107 			ret = -ENOTSUPP;
1108 			goto out;
1109 		}
1110 	}
1111 
1112 	ret = extract_attr_from_ios(ios, &attrs[2]);
1113 	if (ret) {
1114 		EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
1115 		goto out;
1116 	}
1117 	if (attrs[2].len) {
1118 		layout = attrs[2].val_ptr;
1119 		if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
1120 			EXOFS_ERR("%s: unsupported meta-data layout %d\n",
1121 				__func__, layout->gen_func);
1122 			ret = -ENOTSUPP;
1123 			goto out;
1124 		}
1125 	}
1126 
1127 out:
1128 	ore_put_io_state(ios);
1129 	return ret;
1130 }
1131 
__oi_init(struct exofs_i_info * oi)1132 static void __oi_init(struct exofs_i_info *oi)
1133 {
1134 	init_waitqueue_head(&oi->i_wq);
1135 	oi->i_flags = 0;
1136 }
1137 /*
1138  * Fill in an inode read from the OSD and set it up for use
1139  */
exofs_iget(struct super_block * sb,unsigned long ino)1140 struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
1141 {
1142 	struct exofs_i_info *oi;
1143 	struct exofs_fcb fcb;
1144 	struct inode *inode;
1145 	int ret;
1146 
1147 	inode = iget_locked(sb, ino);
1148 	if (!inode)
1149 		return ERR_PTR(-ENOMEM);
1150 	if (!(inode->i_state & I_NEW))
1151 		return inode;
1152 	oi = exofs_i(inode);
1153 	__oi_init(oi);
1154 	exofs_init_comps(&oi->oc, &oi->one_comp, sb->s_fs_info,
1155 			 exofs_oi_objno(oi));
1156 
1157 	/* read the inode from the osd */
1158 	ret = exofs_get_inode(sb, oi, &fcb);
1159 	if (ret)
1160 		goto bad_inode;
1161 
1162 	set_obj_created(oi);
1163 
1164 	/* copy stuff from on-disk struct to in-memory struct */
1165 	inode->i_mode = le16_to_cpu(fcb.i_mode);
1166 	inode->i_uid = le32_to_cpu(fcb.i_uid);
1167 	inode->i_gid = le32_to_cpu(fcb.i_gid);
1168 	set_nlink(inode, le16_to_cpu(fcb.i_links_count));
1169 	inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
1170 	inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
1171 	inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
1172 	inode->i_ctime.tv_nsec =
1173 		inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
1174 	oi->i_commit_size = le64_to_cpu(fcb.i_size);
1175 	i_size_write(inode, oi->i_commit_size);
1176 	inode->i_blkbits = EXOFS_BLKSHIFT;
1177 	inode->i_generation = le32_to_cpu(fcb.i_generation);
1178 
1179 	oi->i_dir_start_lookup = 0;
1180 
1181 	if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
1182 		ret = -ESTALE;
1183 		goto bad_inode;
1184 	}
1185 
1186 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1187 		if (fcb.i_data[0])
1188 			inode->i_rdev =
1189 				old_decode_dev(le32_to_cpu(fcb.i_data[0]));
1190 		else
1191 			inode->i_rdev =
1192 				new_decode_dev(le32_to_cpu(fcb.i_data[1]));
1193 	} else {
1194 		memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
1195 	}
1196 
1197 	inode->i_mapping->backing_dev_info = sb->s_bdi;
1198 	if (S_ISREG(inode->i_mode)) {
1199 		inode->i_op = &exofs_file_inode_operations;
1200 		inode->i_fop = &exofs_file_operations;
1201 		inode->i_mapping->a_ops = &exofs_aops;
1202 	} else if (S_ISDIR(inode->i_mode)) {
1203 		inode->i_op = &exofs_dir_inode_operations;
1204 		inode->i_fop = &exofs_dir_operations;
1205 		inode->i_mapping->a_ops = &exofs_aops;
1206 	} else if (S_ISLNK(inode->i_mode)) {
1207 		if (exofs_inode_is_fast_symlink(inode))
1208 			inode->i_op = &exofs_fast_symlink_inode_operations;
1209 		else {
1210 			inode->i_op = &exofs_symlink_inode_operations;
1211 			inode->i_mapping->a_ops = &exofs_aops;
1212 		}
1213 	} else {
1214 		inode->i_op = &exofs_special_inode_operations;
1215 		if (fcb.i_data[0])
1216 			init_special_inode(inode, inode->i_mode,
1217 			   old_decode_dev(le32_to_cpu(fcb.i_data[0])));
1218 		else
1219 			init_special_inode(inode, inode->i_mode,
1220 			   new_decode_dev(le32_to_cpu(fcb.i_data[1])));
1221 	}
1222 
1223 	unlock_new_inode(inode);
1224 	return inode;
1225 
1226 bad_inode:
1227 	iget_failed(inode);
1228 	return ERR_PTR(ret);
1229 }
1230 
__exofs_wait_obj_created(struct exofs_i_info * oi)1231 int __exofs_wait_obj_created(struct exofs_i_info *oi)
1232 {
1233 	if (!obj_created(oi)) {
1234 		EXOFS_DBGMSG("!obj_created\n");
1235 		BUG_ON(!obj_2bcreated(oi));
1236 		wait_event(oi->i_wq, obj_created(oi));
1237 		EXOFS_DBGMSG("wait_event done\n");
1238 	}
1239 	return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
1240 }
1241 
1242 /*
1243  * Callback function from exofs_new_inode().  The important thing is that we
1244  * set the obj_created flag so that other methods know that the object exists on
1245  * the OSD.
1246  */
create_done(struct ore_io_state * ios,void * p)1247 static void create_done(struct ore_io_state *ios, void *p)
1248 {
1249 	struct inode *inode = p;
1250 	struct exofs_i_info *oi = exofs_i(inode);
1251 	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
1252 	int ret;
1253 
1254 	ret = ore_check_io(ios, NULL);
1255 	ore_put_io_state(ios);
1256 
1257 	atomic_dec(&sbi->s_curr_pending);
1258 
1259 	if (unlikely(ret)) {
1260 		EXOFS_ERR("object=0x%llx creation failed in pid=0x%llx",
1261 			  _LLU(exofs_oi_objno(oi)),
1262 			  _LLU(oi->one_comp.obj.partition));
1263 		/*TODO: When FS is corrupted creation can fail, object already
1264 		 * exist. Get rid of this asynchronous creation, if exist
1265 		 * increment the obj counter and try the next object. Until we
1266 		 * succeed. All these dangling objects will be made into lost
1267 		 * files by chkfs.exofs
1268 		 */
1269 	}
1270 
1271 	set_obj_created(oi);
1272 
1273 	wake_up(&oi->i_wq);
1274 }
1275 
1276 /*
1277  * Set up a new inode and create an object for it on the OSD
1278  */
exofs_new_inode(struct inode * dir,umode_t mode)1279 struct inode *exofs_new_inode(struct inode *dir, umode_t mode)
1280 {
1281 	struct super_block *sb = dir->i_sb;
1282 	struct exofs_sb_info *sbi = sb->s_fs_info;
1283 	struct inode *inode;
1284 	struct exofs_i_info *oi;
1285 	struct ore_io_state *ios;
1286 	int ret;
1287 
1288 	inode = new_inode(sb);
1289 	if (!inode)
1290 		return ERR_PTR(-ENOMEM);
1291 
1292 	oi = exofs_i(inode);
1293 	__oi_init(oi);
1294 
1295 	set_obj_2bcreated(oi);
1296 
1297 	inode->i_mapping->backing_dev_info = sb->s_bdi;
1298 	inode_init_owner(inode, dir, mode);
1299 	inode->i_ino = sbi->s_nextid++;
1300 	inode->i_blkbits = EXOFS_BLKSHIFT;
1301 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1302 	oi->i_commit_size = inode->i_size = 0;
1303 	spin_lock(&sbi->s_next_gen_lock);
1304 	inode->i_generation = sbi->s_next_generation++;
1305 	spin_unlock(&sbi->s_next_gen_lock);
1306 	insert_inode_hash(inode);
1307 
1308 	exofs_init_comps(&oi->oc, &oi->one_comp, sb->s_fs_info,
1309 			 exofs_oi_objno(oi));
1310 	exofs_sbi_write_stats(sbi); /* Make sure new sbi->s_nextid is on disk */
1311 
1312 	mark_inode_dirty(inode);
1313 
1314 	ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
1315 	if (unlikely(ret)) {
1316 		EXOFS_ERR("exofs_new_inode: ore_get_io_state failed\n");
1317 		return ERR_PTR(ret);
1318 	}
1319 
1320 	ios->done = create_done;
1321 	ios->private = inode;
1322 
1323 	ret = ore_create(ios);
1324 	if (ret) {
1325 		ore_put_io_state(ios);
1326 		return ERR_PTR(ret);
1327 	}
1328 	atomic_inc(&sbi->s_curr_pending);
1329 
1330 	return inode;
1331 }
1332 
1333 /*
1334  * struct to pass two arguments to update_inode's callback
1335  */
1336 struct updatei_args {
1337 	struct exofs_sb_info	*sbi;
1338 	struct exofs_fcb	fcb;
1339 };
1340 
1341 /*
1342  * Callback function from exofs_update_inode().
1343  */
updatei_done(struct ore_io_state * ios,void * p)1344 static void updatei_done(struct ore_io_state *ios, void *p)
1345 {
1346 	struct updatei_args *args = p;
1347 
1348 	ore_put_io_state(ios);
1349 
1350 	atomic_dec(&args->sbi->s_curr_pending);
1351 
1352 	kfree(args);
1353 }
1354 
1355 /*
1356  * Write the inode to the OSD.  Just fill up the struct, and set the attribute
1357  * synchronously or asynchronously depending on the do_sync flag.
1358  */
exofs_update_inode(struct inode * inode,int do_sync)1359 static int exofs_update_inode(struct inode *inode, int do_sync)
1360 {
1361 	struct exofs_i_info *oi = exofs_i(inode);
1362 	struct super_block *sb = inode->i_sb;
1363 	struct exofs_sb_info *sbi = sb->s_fs_info;
1364 	struct ore_io_state *ios;
1365 	struct osd_attr attr;
1366 	struct exofs_fcb *fcb;
1367 	struct updatei_args *args;
1368 	int ret;
1369 
1370 	args = kzalloc(sizeof(*args), GFP_KERNEL);
1371 	if (!args) {
1372 		EXOFS_DBGMSG("Failed kzalloc of args\n");
1373 		return -ENOMEM;
1374 	}
1375 
1376 	fcb = &args->fcb;
1377 
1378 	fcb->i_mode = cpu_to_le16(inode->i_mode);
1379 	fcb->i_uid = cpu_to_le32(inode->i_uid);
1380 	fcb->i_gid = cpu_to_le32(inode->i_gid);
1381 	fcb->i_links_count = cpu_to_le16(inode->i_nlink);
1382 	fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1383 	fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1384 	fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1385 	oi->i_commit_size = i_size_read(inode);
1386 	fcb->i_size = cpu_to_le64(oi->i_commit_size);
1387 	fcb->i_generation = cpu_to_le32(inode->i_generation);
1388 
1389 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1390 		if (old_valid_dev(inode->i_rdev)) {
1391 			fcb->i_data[0] =
1392 				cpu_to_le32(old_encode_dev(inode->i_rdev));
1393 			fcb->i_data[1] = 0;
1394 		} else {
1395 			fcb->i_data[0] = 0;
1396 			fcb->i_data[1] =
1397 				cpu_to_le32(new_encode_dev(inode->i_rdev));
1398 			fcb->i_data[2] = 0;
1399 		}
1400 	} else
1401 		memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
1402 
1403 	ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
1404 	if (unlikely(ret)) {
1405 		EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
1406 		goto free_args;
1407 	}
1408 
1409 	attr = g_attr_inode_data;
1410 	attr.val_ptr = fcb;
1411 	ios->out_attr_len = 1;
1412 	ios->out_attr = &attr;
1413 
1414 	wait_obj_created(oi);
1415 
1416 	if (!do_sync) {
1417 		args->sbi = sbi;
1418 		ios->done = updatei_done;
1419 		ios->private = args;
1420 	}
1421 
1422 	ret = ore_write(ios);
1423 	if (!do_sync && !ret) {
1424 		atomic_inc(&sbi->s_curr_pending);
1425 		goto out; /* deallocation in updatei_done */
1426 	}
1427 
1428 	ore_put_io_state(ios);
1429 free_args:
1430 	kfree(args);
1431 out:
1432 	EXOFS_DBGMSG("(0x%lx) do_sync=%d ret=>%d\n",
1433 		     inode->i_ino, do_sync, ret);
1434 	return ret;
1435 }
1436 
exofs_write_inode(struct inode * inode,struct writeback_control * wbc)1437 int exofs_write_inode(struct inode *inode, struct writeback_control *wbc)
1438 {
1439 	/* FIXME: fix fsync and use wbc->sync_mode == WB_SYNC_ALL */
1440 	return exofs_update_inode(inode, 1);
1441 }
1442 
1443 /*
1444  * Callback function from exofs_delete_inode() - don't have much cleaning up to
1445  * do.
1446  */
delete_done(struct ore_io_state * ios,void * p)1447 static void delete_done(struct ore_io_state *ios, void *p)
1448 {
1449 	struct exofs_sb_info *sbi = p;
1450 
1451 	ore_put_io_state(ios);
1452 
1453 	atomic_dec(&sbi->s_curr_pending);
1454 }
1455 
1456 /*
1457  * Called when the refcount of an inode reaches zero.  We remove the object
1458  * from the OSD here.  We make sure the object was created before we try and
1459  * delete it.
1460  */
exofs_evict_inode(struct inode * inode)1461 void exofs_evict_inode(struct inode *inode)
1462 {
1463 	struct exofs_i_info *oi = exofs_i(inode);
1464 	struct super_block *sb = inode->i_sb;
1465 	struct exofs_sb_info *sbi = sb->s_fs_info;
1466 	struct ore_io_state *ios;
1467 	int ret;
1468 
1469 	truncate_inode_pages(&inode->i_data, 0);
1470 
1471 	/* TODO: should do better here */
1472 	if (inode->i_nlink || is_bad_inode(inode))
1473 		goto no_delete;
1474 
1475 	inode->i_size = 0;
1476 	end_writeback(inode);
1477 
1478 	/* if we are deleting an obj that hasn't been created yet, wait.
1479 	 * This also makes sure that create_done cannot be called with an
1480 	 * already evicted inode.
1481 	 */
1482 	wait_obj_created(oi);
1483 	/* ignore the error, attempt a remove anyway */
1484 
1485 	/* Now Remove the OSD objects */
1486 	ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
1487 	if (unlikely(ret)) {
1488 		EXOFS_ERR("%s: ore_get_io_state failed\n", __func__);
1489 		return;
1490 	}
1491 
1492 	ios->done = delete_done;
1493 	ios->private = sbi;
1494 
1495 	ret = ore_remove(ios);
1496 	if (ret) {
1497 		EXOFS_ERR("%s: ore_remove failed\n", __func__);
1498 		ore_put_io_state(ios);
1499 		return;
1500 	}
1501 	atomic_inc(&sbi->s_curr_pending);
1502 
1503 	return;
1504 
1505 no_delete:
1506 	end_writeback(inode);
1507 }
1508