1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2014-2016 Christoph Hellwig.
4 */
5
6#include <linux/vmalloc.h>
7
8#include "blocklayout.h"
9
10#define NFSDBG_FACILITY		NFSDBG_PNFS_LD
11
12static inline struct pnfs_block_extent *
13ext_node(struct rb_node *node)
14{
15	return rb_entry(node, struct pnfs_block_extent, be_node);
16}
17
18static struct pnfs_block_extent *
19ext_tree_first(struct rb_root *root)
20{
21	struct rb_node *node = rb_first(root);
22	return node ? ext_node(node) : NULL;
23}
24
25static struct pnfs_block_extent *
26ext_tree_prev(struct pnfs_block_extent *be)
27{
28	struct rb_node *node = rb_prev(&be->be_node);
29	return node ? ext_node(node) : NULL;
30}
31
32static struct pnfs_block_extent *
33ext_tree_next(struct pnfs_block_extent *be)
34{
35	struct rb_node *node = rb_next(&be->be_node);
36	return node ? ext_node(node) : NULL;
37}
38
39static inline sector_t
40ext_f_end(struct pnfs_block_extent *be)
41{
42	return be->be_f_offset + be->be_length;
43}
44
45static struct pnfs_block_extent *
46__ext_tree_search(struct rb_root *root, sector_t start)
47{
48	struct rb_node *node = root->rb_node;
49	struct pnfs_block_extent *be = NULL;
50
51	while (node) {
52		be = ext_node(node);
53		if (start < be->be_f_offset)
54			node = node->rb_left;
55		else if (start >= ext_f_end(be))
56			node = node->rb_right;
57		else
58			return be;
59	}
60
61	if (be) {
62		if (start < be->be_f_offset)
63			return be;
64
65		if (start >= ext_f_end(be))
66			return ext_tree_next(be);
67	}
68
69	return NULL;
70}
71
72static bool
73ext_can_merge(struct pnfs_block_extent *be1, struct pnfs_block_extent *be2)
74{
75	if (be1->be_state != be2->be_state)
76		return false;
77	if (be1->be_device != be2->be_device)
78		return false;
79
80	if (be1->be_f_offset + be1->be_length != be2->be_f_offset)
81		return false;
82
83	if (be1->be_state != PNFS_BLOCK_NONE_DATA &&
84	    (be1->be_v_offset + be1->be_length != be2->be_v_offset))
85		return false;
86
87	if (be1->be_state == PNFS_BLOCK_INVALID_DATA &&
88	    be1->be_tag != be2->be_tag)
89		return false;
90
91	return true;
92}
93
94static struct pnfs_block_extent *
95ext_try_to_merge_left(struct rb_root *root, struct pnfs_block_extent *be)
96{
97	struct pnfs_block_extent *left = ext_tree_prev(be);
98
99	if (left && ext_can_merge(left, be)) {
100		left->be_length += be->be_length;
101		rb_erase(&be->be_node, root);
102		nfs4_put_deviceid_node(be->be_device);
103		kfree(be);
104		return left;
105	}
106
107	return be;
108}
109
110static struct pnfs_block_extent *
111ext_try_to_merge_right(struct rb_root *root, struct pnfs_block_extent *be)
112{
113	struct pnfs_block_extent *right = ext_tree_next(be);
114
115	if (right && ext_can_merge(be, right)) {
116		be->be_length += right->be_length;
117		rb_erase(&right->be_node, root);
118		nfs4_put_deviceid_node(right->be_device);
119		kfree(right);
120	}
121
122	return be;
123}
124
125static void __ext_put_deviceids(struct list_head *head)
126{
127	struct pnfs_block_extent *be, *tmp;
128
129	list_for_each_entry_safe(be, tmp, head, be_list) {
130		nfs4_put_deviceid_node(be->be_device);
131		kfree(be);
132	}
133}
134
135static void
136__ext_tree_insert(struct rb_root *root,
137		struct pnfs_block_extent *new, bool merge_ok)
138{
139	struct rb_node **p = &root->rb_node, *parent = NULL;
140	struct pnfs_block_extent *be;
141
142	while (*p) {
143		parent = *p;
144		be = ext_node(parent);
145
146		if (new->be_f_offset < be->be_f_offset) {
147			if (merge_ok && ext_can_merge(new, be)) {
148				be->be_f_offset = new->be_f_offset;
149				if (be->be_state != PNFS_BLOCK_NONE_DATA)
150					be->be_v_offset = new->be_v_offset;
151				be->be_length += new->be_length;
152				be = ext_try_to_merge_left(root, be);
153				goto free_new;
154			}
155			p = &(*p)->rb_left;
156		} else if (new->be_f_offset >= ext_f_end(be)) {
157			if (merge_ok && ext_can_merge(be, new)) {
158				be->be_length += new->be_length;
159				be = ext_try_to_merge_right(root, be);
160				goto free_new;
161			}
162			p = &(*p)->rb_right;
163		} else {
164			BUG();
165		}
166	}
167
168	rb_link_node(&new->be_node, parent, p);
169	rb_insert_color(&new->be_node, root);
170	return;
171free_new:
172	nfs4_put_deviceid_node(new->be_device);
173	kfree(new);
174}
175
176static int
177__ext_tree_remove(struct rb_root *root,
178		sector_t start, sector_t end, struct list_head *tmp)
179{
180	struct pnfs_block_extent *be;
181	sector_t len1 = 0, len2 = 0;
182	sector_t orig_v_offset;
183	sector_t orig_len;
184
185	be = __ext_tree_search(root, start);
186	if (!be)
187		return 0;
188	if (be->be_f_offset >= end)
189		return 0;
190
191	orig_v_offset = be->be_v_offset;
192	orig_len = be->be_length;
193
194	if (start > be->be_f_offset)
195		len1 = start - be->be_f_offset;
196	if (ext_f_end(be) > end)
197		len2 = ext_f_end(be) - end;
198
199	if (len2 > 0) {
200		if (len1 > 0) {
201			struct pnfs_block_extent *new;
202
203			new = kzalloc(sizeof(*new), GFP_ATOMIC);
204			if (!new)
205				return -ENOMEM;
206
207			be->be_length = len1;
208
209			new->be_f_offset = end;
210			if (be->be_state != PNFS_BLOCK_NONE_DATA) {
211				new->be_v_offset =
212					orig_v_offset + orig_len - len2;
213			}
214			new->be_length = len2;
215			new->be_state = be->be_state;
216			new->be_tag = be->be_tag;
217			new->be_device = nfs4_get_deviceid(be->be_device);
218
219			__ext_tree_insert(root, new, true);
220		} else {
221			be->be_f_offset = end;
222			if (be->be_state != PNFS_BLOCK_NONE_DATA) {
223				be->be_v_offset =
224					orig_v_offset + orig_len - len2;
225			}
226			be->be_length = len2;
227		}
228	} else {
229		if (len1 > 0) {
230			be->be_length = len1;
231			be = ext_tree_next(be);
232		}
233
234		while (be && ext_f_end(be) <= end) {
235			struct pnfs_block_extent *next = ext_tree_next(be);
236
237			rb_erase(&be->be_node, root);
238			list_add_tail(&be->be_list, tmp);
239			be = next;
240		}
241
242		if (be && be->be_f_offset < end) {
243			len1 = ext_f_end(be) - end;
244			be->be_f_offset = end;
245			if (be->be_state != PNFS_BLOCK_NONE_DATA)
246				be->be_v_offset += be->be_length - len1;
247			be->be_length = len1;
248		}
249	}
250
251	return 0;
252}
253
254int
255ext_tree_insert(struct pnfs_block_layout *bl, struct pnfs_block_extent *new)
256{
257	struct pnfs_block_extent *be;
258	struct rb_root *root;
259	int err = 0;
260
261	switch (new->be_state) {
262	case PNFS_BLOCK_READWRITE_DATA:
263	case PNFS_BLOCK_INVALID_DATA:
264		root = &bl->bl_ext_rw;
265		break;
266	case PNFS_BLOCK_READ_DATA:
267	case PNFS_BLOCK_NONE_DATA:
268		root = &bl->bl_ext_ro;
269		break;
270	default:
271		dprintk("invalid extent type\n");
272		return -EINVAL;
273	}
274
275	spin_lock(&bl->bl_ext_lock);
276retry:
277	be = __ext_tree_search(root, new->be_f_offset);
278	if (!be || be->be_f_offset >= ext_f_end(new)) {
279		__ext_tree_insert(root, new, true);
280	} else if (new->be_f_offset >= be->be_f_offset) {
281		if (ext_f_end(new) <= ext_f_end(be)) {
282			nfs4_put_deviceid_node(new->be_device);
283			kfree(new);
284		} else {
285			sector_t new_len = ext_f_end(new) - ext_f_end(be);
286			sector_t diff = new->be_length - new_len;
287
288			new->be_f_offset += diff;
289			new->be_v_offset += diff;
290			new->be_length = new_len;
291			goto retry;
292		}
293	} else if (ext_f_end(new) <= ext_f_end(be)) {
294		new->be_length = be->be_f_offset - new->be_f_offset;
295		__ext_tree_insert(root, new, true);
296	} else {
297		struct pnfs_block_extent *split;
298		sector_t new_len = ext_f_end(new) - ext_f_end(be);
299		sector_t diff = new->be_length - new_len;
300
301		split = kmemdup(new, sizeof(*new), GFP_ATOMIC);
302		if (!split) {
303			err = -EINVAL;
304			goto out;
305		}
306
307		split->be_length = be->be_f_offset - split->be_f_offset;
308		split->be_device = nfs4_get_deviceid(new->be_device);
309		__ext_tree_insert(root, split, true);
310
311		new->be_f_offset += diff;
312		new->be_v_offset += diff;
313		new->be_length = new_len;
314		goto retry;
315	}
316out:
317	spin_unlock(&bl->bl_ext_lock);
318	return err;
319}
320
321static bool
322__ext_tree_lookup(struct rb_root *root, sector_t isect,
323		struct pnfs_block_extent *ret)
324{
325	struct rb_node *node;
326	struct pnfs_block_extent *be;
327
328	node = root->rb_node;
329	while (node) {
330		be = ext_node(node);
331		if (isect < be->be_f_offset)
332			node = node->rb_left;
333		else if (isect >= ext_f_end(be))
334			node = node->rb_right;
335		else {
336			*ret = *be;
337			return true;
338		}
339	}
340
341	return false;
342}
343
344bool
345ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
346	    struct pnfs_block_extent *ret, bool rw)
347{
348	bool found = false;
349
350	spin_lock(&bl->bl_ext_lock);
351	if (!rw)
352		found = __ext_tree_lookup(&bl->bl_ext_ro, isect, ret);
353	if (!found)
354		found = __ext_tree_lookup(&bl->bl_ext_rw, isect, ret);
355	spin_unlock(&bl->bl_ext_lock);
356
357	return found;
358}
359
360int ext_tree_remove(struct pnfs_block_layout *bl, bool rw,
361		sector_t start, sector_t end)
362{
363	int err, err2;
364	LIST_HEAD(tmp);
365
366	spin_lock(&bl->bl_ext_lock);
367	err = __ext_tree_remove(&bl->bl_ext_ro, start, end, &tmp);
368	if (rw) {
369		err2 = __ext_tree_remove(&bl->bl_ext_rw, start, end, &tmp);
370		if (!err)
371			err = err2;
372	}
373	spin_unlock(&bl->bl_ext_lock);
374
375	__ext_put_deviceids(&tmp);
376	return err;
377}
378
379static int
380ext_tree_split(struct rb_root *root, struct pnfs_block_extent *be,
381		sector_t split)
382{
383	struct pnfs_block_extent *new;
384	sector_t orig_len = be->be_length;
385
386	new = kzalloc(sizeof(*new), GFP_ATOMIC);
387	if (!new)
388		return -ENOMEM;
389
390	be->be_length = split - be->be_f_offset;
391
392	new->be_f_offset = split;
393	if (be->be_state != PNFS_BLOCK_NONE_DATA)
394		new->be_v_offset = be->be_v_offset + be->be_length;
395	new->be_length = orig_len - be->be_length;
396	new->be_state = be->be_state;
397	new->be_tag = be->be_tag;
398	new->be_device = nfs4_get_deviceid(be->be_device);
399
400	__ext_tree_insert(root, new, false);
401	return 0;
402}
403
404int
405ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start,
406		sector_t len, u64 lwb)
407{
408	struct rb_root *root = &bl->bl_ext_rw;
409	sector_t end = start + len;
410	struct pnfs_block_extent *be;
411	int err = 0;
412	LIST_HEAD(tmp);
413
414	spin_lock(&bl->bl_ext_lock);
415	/*
416	 * First remove all COW extents or holes from written to range.
417	 */
418	err = __ext_tree_remove(&bl->bl_ext_ro, start, end, &tmp);
419	if (err)
420		goto out;
421
422	/*
423	 * Then mark all invalid extents in the range as written to.
424	 */
425	for (be = __ext_tree_search(root, start); be; be = ext_tree_next(be)) {
426		if (be->be_f_offset >= end)
427			break;
428
429		if (be->be_state != PNFS_BLOCK_INVALID_DATA || be->be_tag)
430			continue;
431
432		if (be->be_f_offset < start) {
433			struct pnfs_block_extent *left = ext_tree_prev(be);
434
435			if (left && ext_can_merge(left, be)) {
436				sector_t diff = start - be->be_f_offset;
437
438				left->be_length += diff;
439
440				be->be_f_offset += diff;
441				be->be_v_offset += diff;
442				be->be_length -= diff;
443			} else {
444				err = ext_tree_split(root, be, start);
445				if (err)
446					goto out;
447			}
448		}
449
450		if (ext_f_end(be) > end) {
451			struct pnfs_block_extent *right = ext_tree_next(be);
452
453			if (right && ext_can_merge(be, right)) {
454				sector_t diff = end - be->be_f_offset;
455
456				be->be_length -= diff;
457
458				right->be_f_offset -= diff;
459				right->be_v_offset -= diff;
460				right->be_length += diff;
461			} else {
462				err = ext_tree_split(root, be, end);
463				if (err)
464					goto out;
465			}
466		}
467
468		if (be->be_f_offset >= start && ext_f_end(be) <= end) {
469			be->be_tag = EXTENT_WRITTEN;
470			be = ext_try_to_merge_left(root, be);
471			be = ext_try_to_merge_right(root, be);
472		}
473	}
474out:
475	if (bl->bl_lwb < lwb)
476		bl->bl_lwb = lwb;
477	spin_unlock(&bl->bl_ext_lock);
478
479	__ext_put_deviceids(&tmp);
480	return err;
481}
482
483static size_t ext_tree_layoutupdate_size(struct pnfs_block_layout *bl, size_t count)
484{
485	if (bl->bl_scsi_layout)
486		return sizeof(__be32) + PNFS_SCSI_RANGE_SIZE * count;
487	else
488		return sizeof(__be32) + PNFS_BLOCK_EXTENT_SIZE * count;
489}
490
491static void ext_tree_free_commitdata(struct nfs4_layoutcommit_args *arg,
492		size_t buffer_size)
493{
494	if (arg->layoutupdate_pages != &arg->layoutupdate_page) {
495		int nr_pages = DIV_ROUND_UP(buffer_size, PAGE_SIZE), i;
496
497		for (i = 0; i < nr_pages; i++)
498			put_page(arg->layoutupdate_pages[i]);
499		vfree(arg->start_p);
500		kfree(arg->layoutupdate_pages);
501	} else {
502		put_page(arg->layoutupdate_page);
503	}
504}
505
506static __be32 *encode_block_extent(struct pnfs_block_extent *be, __be32 *p)
507{
508	p = xdr_encode_opaque_fixed(p, be->be_device->deviceid.data,
509			NFS4_DEVICEID4_SIZE);
510	p = xdr_encode_hyper(p, be->be_f_offset << SECTOR_SHIFT);
511	p = xdr_encode_hyper(p, be->be_length << SECTOR_SHIFT);
512	p = xdr_encode_hyper(p, 0LL);
513	*p++ = cpu_to_be32(PNFS_BLOCK_READWRITE_DATA);
514	return p;
515}
516
517static __be32 *encode_scsi_range(struct pnfs_block_extent *be, __be32 *p)
518{
519	p = xdr_encode_hyper(p, be->be_f_offset << SECTOR_SHIFT);
520	return xdr_encode_hyper(p, be->be_length << SECTOR_SHIFT);
521}
522
523static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p,
524		size_t buffer_size, size_t *count, __u64 *lastbyte)
525{
526	struct pnfs_block_extent *be;
527	int ret = 0;
528
529	spin_lock(&bl->bl_ext_lock);
530	for (be = ext_tree_first(&bl->bl_ext_rw); be; be = ext_tree_next(be)) {
531		if (be->be_state != PNFS_BLOCK_INVALID_DATA ||
532		    be->be_tag != EXTENT_WRITTEN)
533			continue;
534
535		(*count)++;
536		if (ext_tree_layoutupdate_size(bl, *count) > buffer_size) {
537			/* keep counting.. */
538			ret = -ENOSPC;
539			continue;
540		}
541
542		if (bl->bl_scsi_layout)
543			p = encode_scsi_range(be, p);
544		else
545			p = encode_block_extent(be, p);
546		be->be_tag = EXTENT_COMMITTING;
547	}
548	*lastbyte = bl->bl_lwb - 1;
549	bl->bl_lwb = 0;
550	spin_unlock(&bl->bl_ext_lock);
551
552	return ret;
553}
554
555int
556ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg)
557{
558	struct pnfs_block_layout *bl = BLK_LO2EXT(NFS_I(arg->inode)->layout);
559	size_t count = 0, buffer_size = PAGE_SIZE;
560	__be32 *start_p;
561	int ret;
562
563	dprintk("%s enter\n", __func__);
564
565	arg->layoutupdate_page = alloc_page(GFP_NOFS);
566	if (!arg->layoutupdate_page)
567		return -ENOMEM;
568	start_p = page_address(arg->layoutupdate_page);
569	arg->layoutupdate_pages = &arg->layoutupdate_page;
570
571retry:
572	ret = ext_tree_encode_commit(bl, start_p + 1, buffer_size, &count, &arg->lastbytewritten);
573	if (unlikely(ret)) {
574		ext_tree_free_commitdata(arg, buffer_size);
575
576		buffer_size = ext_tree_layoutupdate_size(bl, count);
577		count = 0;
578
579		arg->layoutupdate_pages =
580			kcalloc(DIV_ROUND_UP(buffer_size, PAGE_SIZE),
581				sizeof(struct page *), GFP_NOFS);
582		if (!arg->layoutupdate_pages)
583			return -ENOMEM;
584
585		start_p = __vmalloc(buffer_size, GFP_NOFS);
586		if (!start_p) {
587			kfree(arg->layoutupdate_pages);
588			return -ENOMEM;
589		}
590
591		goto retry;
592	}
593
594	*start_p = cpu_to_be32(count);
595	arg->layoutupdate_len = ext_tree_layoutupdate_size(bl, count);
596
597	if (unlikely(arg->layoutupdate_pages != &arg->layoutupdate_page)) {
598		void *p = start_p, *end = p + arg->layoutupdate_len;
599		struct page *page = NULL;
600		int i = 0;
601
602		arg->start_p = start_p;
603		for ( ; p < end; p += PAGE_SIZE) {
604			page = vmalloc_to_page(p);
605			arg->layoutupdate_pages[i++] = page;
606			get_page(page);
607		}
608	}
609
610	dprintk("%s found %zu ranges\n", __func__, count);
611	return 0;
612}
613
614void
615ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status)
616{
617	struct pnfs_block_layout *bl = BLK_LO2EXT(NFS_I(arg->inode)->layout);
618	struct rb_root *root = &bl->bl_ext_rw;
619	struct pnfs_block_extent *be;
620
621	dprintk("%s status %d\n", __func__, status);
622
623	ext_tree_free_commitdata(arg, arg->layoutupdate_len);
624
625	spin_lock(&bl->bl_ext_lock);
626	for (be = ext_tree_first(root); be; be = ext_tree_next(be)) {
627		if (be->be_state != PNFS_BLOCK_INVALID_DATA ||
628		    be->be_tag != EXTENT_COMMITTING)
629			continue;
630
631		if (status) {
632			/*
633			 * Mark as written and try again.
634			 *
635			 * XXX: some real error handling here wouldn't hurt..
636			 */
637			be->be_tag = EXTENT_WRITTEN;
638		} else {
639			be->be_state = PNFS_BLOCK_READWRITE_DATA;
640			be->be_tag = 0;
641		}
642
643		be = ext_try_to_merge_left(root, be);
644		be = ext_try_to_merge_right(root, be);
645	}
646	spin_unlock(&bl->bl_ext_lock);
647}
648