1/*
2 *  linux/fs/nfs/blocklayout/blocklayout.c
3 *
4 *  Module for the NFSv4.1 pNFS block layout driver.
5 *
6 *  Copyright (c) 2006 The Regents of the University of Michigan.
7 *  All rights reserved.
8 *
9 *  Andy Adamson <andros@citi.umich.edu>
10 *  Fred Isaman <iisaman@umich.edu>
11 *
12 * permission is granted to use, copy, create derivative works and
13 * redistribute this software and such derivative works for any purpose,
14 * so long as the name of the university of michigan is not used in
15 * any advertising or publicity pertaining to the use or distribution
16 * of this software without specific, written prior authorization.  if
17 * the above copyright notice or any other identification of the
18 * university of michigan is included in any copy of any portion of
19 * this software, then the disclaimer below must also be included.
20 *
21 * this software is provided as is, without representation from the
22 * university of michigan as to its fitness for any purpose, and without
23 * warranty by the university of michigan of any kind, either express
24 * or implied, including without limitation the implied warranties of
25 * merchantability and fitness for a particular purpose.  the regents
26 * of the university of michigan shall not be liable for any damages,
27 * including special, indirect, incidental, or consequential damages,
28 * with respect to any claim arising out or in connection with the use
29 * of the software, even if it has been or is hereafter advised of the
30 * possibility of such damages.
31 */
32
33#include <linux/module.h>
34#include <linux/init.h>
35#include <linux/mount.h>
36#include <linux/namei.h>
37#include <linux/bio.h>		/* struct bio */
38#include <linux/prefetch.h>
39#include <linux/pagevec.h>
40
41#include "../pnfs.h"
42#include "../nfs4session.h"
43#include "../internal.h"
44#include "blocklayout.h"
45
46#define NFSDBG_FACILITY	NFSDBG_PNFS_LD
47
48MODULE_LICENSE("GPL");
49MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>");
50MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
51
52static bool is_hole(struct pnfs_block_extent *be)
53{
54	switch (be->be_state) {
55	case PNFS_BLOCK_NONE_DATA:
56		return true;
57	case PNFS_BLOCK_INVALID_DATA:
58		return be->be_tag ? false : true;
59	default:
60		return false;
61	}
62}
63
64/* The data we are handed might be spread across several bios.  We need
65 * to track when the last one is finished.
66 */
67struct parallel_io {
68	struct kref refcnt;
69	void (*pnfs_callback) (void *data);
70	void *data;
71};
72
73static inline struct parallel_io *alloc_parallel(void *data)
74{
75	struct parallel_io *rv;
76
77	rv  = kmalloc(sizeof(*rv), GFP_NOFS);
78	if (rv) {
79		rv->data = data;
80		kref_init(&rv->refcnt);
81	}
82	return rv;
83}
84
85static inline void get_parallel(struct parallel_io *p)
86{
87	kref_get(&p->refcnt);
88}
89
90static void destroy_parallel(struct kref *kref)
91{
92	struct parallel_io *p = container_of(kref, struct parallel_io, refcnt);
93
94	dprintk("%s enter\n", __func__);
95	p->pnfs_callback(p->data);
96	kfree(p);
97}
98
99static inline void put_parallel(struct parallel_io *p)
100{
101	kref_put(&p->refcnt, destroy_parallel);
102}
103
104static struct bio *
105bl_submit_bio(struct bio *bio)
106{
107	if (bio) {
108		get_parallel(bio->bi_private);
109		dprintk("%s submitting %s bio %u@%llu\n", __func__,
110			bio_op(bio) == READ ? "read" : "write",
111			bio->bi_iter.bi_size,
112			(unsigned long long)bio->bi_iter.bi_sector);
113		submit_bio(bio);
114	}
115	return NULL;
116}
117
118static bool offset_in_map(u64 offset, struct pnfs_block_dev_map *map)
119{
120	return offset >= map->start && offset < map->start + map->len;
121}
122
123static struct bio *
124do_add_page_to_bio(struct bio *bio, int npg, enum req_op op, sector_t isect,
125		struct page *page, struct pnfs_block_dev_map *map,
126		struct pnfs_block_extent *be, bio_end_io_t end_io,
127		struct parallel_io *par, unsigned int offset, int *len)
128{
129	struct pnfs_block_dev *dev =
130		container_of(be->be_device, struct pnfs_block_dev, node);
131	u64 disk_addr, end;
132
133	dprintk("%s: npg %d rw %d isect %llu offset %u len %d\n", __func__,
134		npg, (__force u32)op, (unsigned long long)isect, offset, *len);
135
136	/* translate to device offset */
137	isect += be->be_v_offset;
138	isect -= be->be_f_offset;
139
140	/* translate to physical disk offset */
141	disk_addr = (u64)isect << SECTOR_SHIFT;
142	if (!offset_in_map(disk_addr, map)) {
143		if (!dev->map(dev, disk_addr, map) || !offset_in_map(disk_addr, map))
144			return ERR_PTR(-EIO);
145		bio = bl_submit_bio(bio);
146	}
147	disk_addr += map->disk_offset;
148	disk_addr -= map->start;
149
150	/* limit length to what the device mapping allows */
151	end = disk_addr + *len;
152	if (end >= map->start + map->len)
153		*len = map->start + map->len - disk_addr;
154
155retry:
156	if (!bio) {
157		bio = bio_alloc(map->bdev, bio_max_segs(npg), op, GFP_NOIO);
158		bio->bi_iter.bi_sector = disk_addr >> SECTOR_SHIFT;
159		bio->bi_end_io = end_io;
160		bio->bi_private = par;
161	}
162	if (bio_add_page(bio, page, *len, offset) < *len) {
163		bio = bl_submit_bio(bio);
164		goto retry;
165	}
166	return bio;
167}
168
169static void bl_mark_devices_unavailable(struct nfs_pgio_header *header, bool rw)
170{
171	struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
172	size_t bytes_left = header->args.count;
173	sector_t isect, extent_length = 0;
174	struct pnfs_block_extent be;
175
176	isect = header->args.offset >> SECTOR_SHIFT;
177	bytes_left += header->args.offset - (isect << SECTOR_SHIFT);
178
179	while (bytes_left > 0) {
180		if (!ext_tree_lookup(bl, isect, &be, rw))
181				return;
182		extent_length = be.be_length - (isect - be.be_f_offset);
183		nfs4_mark_deviceid_unavailable(be.be_device);
184		isect += extent_length;
185		if (bytes_left > extent_length << SECTOR_SHIFT)
186			bytes_left -= extent_length << SECTOR_SHIFT;
187		else
188			bytes_left = 0;
189	}
190}
191
192static void bl_end_io_read(struct bio *bio)
193{
194	struct parallel_io *par = bio->bi_private;
195
196	if (bio->bi_status) {
197		struct nfs_pgio_header *header = par->data;
198
199		if (!header->pnfs_error)
200			header->pnfs_error = -EIO;
201		pnfs_set_lo_fail(header->lseg);
202		bl_mark_devices_unavailable(header, false);
203	}
204
205	bio_put(bio);
206	put_parallel(par);
207}
208
209static void bl_read_cleanup(struct work_struct *work)
210{
211	struct rpc_task *task;
212	struct nfs_pgio_header *hdr;
213	dprintk("%s enter\n", __func__);
214	task = container_of(work, struct rpc_task, u.tk_work);
215	hdr = container_of(task, struct nfs_pgio_header, task);
216	pnfs_ld_read_done(hdr);
217}
218
219static void
220bl_end_par_io_read(void *data)
221{
222	struct nfs_pgio_header *hdr = data;
223
224	hdr->task.tk_status = hdr->pnfs_error;
225	INIT_WORK(&hdr->task.u.tk_work, bl_read_cleanup);
226	schedule_work(&hdr->task.u.tk_work);
227}
228
229static enum pnfs_try_status
230bl_read_pagelist(struct nfs_pgio_header *header)
231{
232	struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
233	struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
234	struct bio *bio = NULL;
235	struct pnfs_block_extent be;
236	sector_t isect, extent_length = 0;
237	struct parallel_io *par;
238	loff_t f_offset = header->args.offset;
239	size_t bytes_left = header->args.count;
240	unsigned int pg_offset = header->args.pgbase, pg_len;
241	struct page **pages = header->args.pages;
242	int pg_index = header->args.pgbase >> PAGE_SHIFT;
243	const bool is_dio = (header->dreq != NULL);
244	struct blk_plug plug;
245	int i;
246
247	dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__,
248		header->page_array.npages, f_offset,
249		(unsigned int)header->args.count);
250
251	par = alloc_parallel(header);
252	if (!par)
253		return PNFS_NOT_ATTEMPTED;
254	par->pnfs_callback = bl_end_par_io_read;
255
256	blk_start_plug(&plug);
257
258	isect = (sector_t) (f_offset >> SECTOR_SHIFT);
259	/* Code assumes extents are page-aligned */
260	for (i = pg_index; i < header->page_array.npages; i++) {
261		if (extent_length <= 0) {
262			/* We've used up the previous extent */
263			bio = bl_submit_bio(bio);
264
265			/* Get the next one */
266			if (!ext_tree_lookup(bl, isect, &be, false)) {
267				header->pnfs_error = -EIO;
268				goto out;
269			}
270			extent_length = be.be_length - (isect - be.be_f_offset);
271		}
272
273		if (is_dio) {
274			if (pg_offset + bytes_left > PAGE_SIZE)
275				pg_len = PAGE_SIZE - pg_offset;
276			else
277				pg_len = bytes_left;
278		} else {
279			BUG_ON(pg_offset != 0);
280			pg_len = PAGE_SIZE;
281		}
282
283		if (is_hole(&be)) {
284			bio = bl_submit_bio(bio);
285			/* Fill hole w/ zeroes w/o accessing device */
286			dprintk("%s Zeroing page for hole\n", __func__);
287			zero_user_segment(pages[i], pg_offset, pg_len);
288
289			/* invalidate map */
290			map.start = NFS4_MAX_UINT64;
291		} else {
292			bio = do_add_page_to_bio(bio,
293						 header->page_array.npages - i,
294						 REQ_OP_READ,
295						 isect, pages[i], &map, &be,
296						 bl_end_io_read, par,
297						 pg_offset, &pg_len);
298			if (IS_ERR(bio)) {
299				header->pnfs_error = PTR_ERR(bio);
300				bio = NULL;
301				goto out;
302			}
303		}
304		isect += (pg_len >> SECTOR_SHIFT);
305		extent_length -= (pg_len >> SECTOR_SHIFT);
306		f_offset += pg_len;
307		bytes_left -= pg_len;
308		pg_offset = 0;
309	}
310	if ((isect << SECTOR_SHIFT) >= header->inode->i_size) {
311		header->res.eof = 1;
312		header->res.count = header->inode->i_size - header->args.offset;
313	} else {
314		header->res.count = (isect << SECTOR_SHIFT) - header->args.offset;
315	}
316out:
317	bl_submit_bio(bio);
318	blk_finish_plug(&plug);
319	put_parallel(par);
320	return PNFS_ATTEMPTED;
321}
322
323static void bl_end_io_write(struct bio *bio)
324{
325	struct parallel_io *par = bio->bi_private;
326	struct nfs_pgio_header *header = par->data;
327
328	if (bio->bi_status) {
329		if (!header->pnfs_error)
330			header->pnfs_error = -EIO;
331		pnfs_set_lo_fail(header->lseg);
332		bl_mark_devices_unavailable(header, true);
333	}
334	bio_put(bio);
335	put_parallel(par);
336}
337
338/* Function scheduled for call during bl_end_par_io_write,
339 * it marks sectors as written and extends the commitlist.
340 */
341static void bl_write_cleanup(struct work_struct *work)
342{
343	struct rpc_task *task = container_of(work, struct rpc_task, u.tk_work);
344	struct nfs_pgio_header *hdr =
345			container_of(task, struct nfs_pgio_header, task);
346
347	dprintk("%s enter\n", __func__);
348
349	if (likely(!hdr->pnfs_error)) {
350		struct pnfs_block_layout *bl = BLK_LSEG2EXT(hdr->lseg);
351		u64 start = hdr->args.offset & (loff_t)PAGE_MASK;
352		u64 end = (hdr->args.offset + hdr->args.count +
353			PAGE_SIZE - 1) & (loff_t)PAGE_MASK;
354		u64 lwb = hdr->args.offset + hdr->args.count;
355
356		ext_tree_mark_written(bl, start >> SECTOR_SHIFT,
357					(end - start) >> SECTOR_SHIFT, lwb);
358	}
359
360	pnfs_ld_write_done(hdr);
361}
362
363/* Called when last of bios associated with a bl_write_pagelist call finishes */
364static void bl_end_par_io_write(void *data)
365{
366	struct nfs_pgio_header *hdr = data;
367
368	hdr->task.tk_status = hdr->pnfs_error;
369	hdr->verf.committed = NFS_FILE_SYNC;
370	INIT_WORK(&hdr->task.u.tk_work, bl_write_cleanup);
371	schedule_work(&hdr->task.u.tk_work);
372}
373
374static enum pnfs_try_status
375bl_write_pagelist(struct nfs_pgio_header *header, int sync)
376{
377	struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
378	struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
379	struct bio *bio = NULL;
380	struct pnfs_block_extent be;
381	sector_t isect, extent_length = 0;
382	struct parallel_io *par = NULL;
383	loff_t offset = header->args.offset;
384	size_t count = header->args.count;
385	struct page **pages = header->args.pages;
386	int pg_index = header->args.pgbase >> PAGE_SHIFT;
387	unsigned int pg_len;
388	struct blk_plug plug;
389	int i;
390
391	dprintk("%s enter, %zu@%lld\n", __func__, count, offset);
392
393	/* At this point, header->page_aray is a (sequential) list of nfs_pages.
394	 * We want to write each, and if there is an error set pnfs_error
395	 * to have it redone using nfs.
396	 */
397	par = alloc_parallel(header);
398	if (!par)
399		return PNFS_NOT_ATTEMPTED;
400	par->pnfs_callback = bl_end_par_io_write;
401
402	blk_start_plug(&plug);
403
404	/* we always write out the whole page */
405	offset = offset & (loff_t)PAGE_MASK;
406	isect = offset >> SECTOR_SHIFT;
407
408	for (i = pg_index; i < header->page_array.npages; i++) {
409		if (extent_length <= 0) {
410			/* We've used up the previous extent */
411			bio = bl_submit_bio(bio);
412			/* Get the next one */
413			if (!ext_tree_lookup(bl, isect, &be, true)) {
414				header->pnfs_error = -EINVAL;
415				goto out;
416			}
417
418			extent_length = be.be_length - (isect - be.be_f_offset);
419		}
420
421		pg_len = PAGE_SIZE;
422		bio = do_add_page_to_bio(bio, header->page_array.npages - i,
423					 REQ_OP_WRITE, isect, pages[i], &map,
424					 &be, bl_end_io_write, par, 0, &pg_len);
425		if (IS_ERR(bio)) {
426			header->pnfs_error = PTR_ERR(bio);
427			bio = NULL;
428			goto out;
429		}
430
431		offset += pg_len;
432		count -= pg_len;
433		isect += (pg_len >> SECTOR_SHIFT);
434		extent_length -= (pg_len >> SECTOR_SHIFT);
435	}
436
437	header->res.count = header->args.count;
438out:
439	bl_submit_bio(bio);
440	blk_finish_plug(&plug);
441	put_parallel(par);
442	return PNFS_ATTEMPTED;
443}
444
445static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo)
446{
447	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
448	int err;
449
450	dprintk("%s enter\n", __func__);
451
452	err = ext_tree_remove(bl, true, 0, LLONG_MAX);
453	WARN_ON(err);
454
455	kfree_rcu(bl, bl_layout.plh_rcu);
456}
457
458static struct pnfs_layout_hdr *__bl_alloc_layout_hdr(struct inode *inode,
459		gfp_t gfp_flags, bool is_scsi_layout)
460{
461	struct pnfs_block_layout *bl;
462
463	dprintk("%s enter\n", __func__);
464	bl = kzalloc(sizeof(*bl), gfp_flags);
465	if (!bl)
466		return NULL;
467
468	bl->bl_ext_rw = RB_ROOT;
469	bl->bl_ext_ro = RB_ROOT;
470	spin_lock_init(&bl->bl_ext_lock);
471
472	bl->bl_scsi_layout = is_scsi_layout;
473	return &bl->bl_layout;
474}
475
476static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode,
477						   gfp_t gfp_flags)
478{
479	return __bl_alloc_layout_hdr(inode, gfp_flags, false);
480}
481
482static struct pnfs_layout_hdr *sl_alloc_layout_hdr(struct inode *inode,
483						   gfp_t gfp_flags)
484{
485	return __bl_alloc_layout_hdr(inode, gfp_flags, true);
486}
487
488static void bl_free_lseg(struct pnfs_layout_segment *lseg)
489{
490	dprintk("%s enter\n", __func__);
491	kfree(lseg);
492}
493
494/* Tracks info needed to ensure extents in layout obey constraints of spec */
495struct layout_verification {
496	u32 mode;	/* R or RW */
497	u64 start;	/* Expected start of next non-COW extent */
498	u64 inval;	/* Start of INVAL coverage */
499	u64 cowread;	/* End of COW read coverage */
500};
501
502/* Verify the extent meets the layout requirements of the pnfs-block draft,
503 * section 2.3.1.
504 */
505static int verify_extent(struct pnfs_block_extent *be,
506			 struct layout_verification *lv)
507{
508	if (lv->mode == IOMODE_READ) {
509		if (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
510		    be->be_state == PNFS_BLOCK_INVALID_DATA)
511			return -EIO;
512		if (be->be_f_offset != lv->start)
513			return -EIO;
514		lv->start += be->be_length;
515		return 0;
516	}
517	/* lv->mode == IOMODE_RW */
518	if (be->be_state == PNFS_BLOCK_READWRITE_DATA) {
519		if (be->be_f_offset != lv->start)
520			return -EIO;
521		if (lv->cowread > lv->start)
522			return -EIO;
523		lv->start += be->be_length;
524		lv->inval = lv->start;
525		return 0;
526	} else if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
527		if (be->be_f_offset != lv->start)
528			return -EIO;
529		lv->start += be->be_length;
530		return 0;
531	} else if (be->be_state == PNFS_BLOCK_READ_DATA) {
532		if (be->be_f_offset > lv->start)
533			return -EIO;
534		if (be->be_f_offset < lv->inval)
535			return -EIO;
536		if (be->be_f_offset < lv->cowread)
537			return -EIO;
538		/* It looks like you might want to min this with lv->start,
539		 * but you really don't.
540		 */
541		lv->inval = lv->inval + be->be_length;
542		lv->cowread = be->be_f_offset + be->be_length;
543		return 0;
544	} else
545		return -EIO;
546}
547
548static int decode_sector_number(__be32 **rp, sector_t *sp)
549{
550	uint64_t s;
551
552	*rp = xdr_decode_hyper(*rp, &s);
553	if (s & 0x1ff) {
554		printk(KERN_WARNING "NFS: %s: sector not aligned\n", __func__);
555		return -1;
556	}
557	*sp = s >> SECTOR_SHIFT;
558	return 0;
559}
560
561static struct nfs4_deviceid_node *
562bl_find_get_deviceid(struct nfs_server *server,
563		const struct nfs4_deviceid *id, const struct cred *cred,
564		gfp_t gfp_mask)
565{
566	struct nfs4_deviceid_node *node;
567	unsigned long start, end;
568
569retry:
570	node = nfs4_find_get_deviceid(server, id, cred, gfp_mask);
571	if (!node)
572		return ERR_PTR(-ENODEV);
573
574	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags) == 0)
575		return node;
576
577	end = jiffies;
578	start = end - PNFS_DEVICE_RETRY_TIMEOUT;
579	if (!time_in_range(node->timestamp_unavailable, start, end)) {
580		nfs4_delete_deviceid(node->ld, node->nfs_client, id);
581		goto retry;
582	}
583
584	nfs4_put_deviceid_node(node);
585	return ERR_PTR(-ENODEV);
586}
587
588static int
589bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo,
590		struct layout_verification *lv, struct list_head *extents,
591		gfp_t gfp_mask)
592{
593	struct pnfs_block_extent *be;
594	struct nfs4_deviceid id;
595	int error;
596	__be32 *p;
597
598	p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE);
599	if (!p)
600		return -EIO;
601
602	be = kzalloc(sizeof(*be), GFP_NOFS);
603	if (!be)
604		return -ENOMEM;
605
606	memcpy(&id, p, NFS4_DEVICEID4_SIZE);
607	p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
608
609	be->be_device = bl_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id,
610						lo->plh_lc_cred, gfp_mask);
611	if (IS_ERR(be->be_device)) {
612		error = PTR_ERR(be->be_device);
613		goto out_free_be;
614	}
615
616	/*
617	 * The next three values are read in as bytes, but stored in the
618	 * extent structure in 512-byte granularity.
619	 */
620	error = -EIO;
621	if (decode_sector_number(&p, &be->be_f_offset) < 0)
622		goto out_put_deviceid;
623	if (decode_sector_number(&p, &be->be_length) < 0)
624		goto out_put_deviceid;
625	if (decode_sector_number(&p, &be->be_v_offset) < 0)
626		goto out_put_deviceid;
627	be->be_state = be32_to_cpup(p++);
628
629	error = verify_extent(be, lv);
630	if (error) {
631		dprintk("%s: extent verification failed\n", __func__);
632		goto out_put_deviceid;
633	}
634
635	list_add_tail(&be->be_list, extents);
636	return 0;
637
638out_put_deviceid:
639	nfs4_put_deviceid_node(be->be_device);
640out_free_be:
641	kfree(be);
642	return error;
643}
644
645static struct pnfs_layout_segment *
646bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr,
647		gfp_t gfp_mask)
648{
649	struct layout_verification lv = {
650		.mode = lgr->range.iomode,
651		.start = lgr->range.offset >> SECTOR_SHIFT,
652		.inval = lgr->range.offset >> SECTOR_SHIFT,
653		.cowread = lgr->range.offset >> SECTOR_SHIFT,
654	};
655	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
656	struct pnfs_layout_segment *lseg;
657	struct xdr_buf buf;
658	struct xdr_stream xdr;
659	struct page *scratch;
660	int status, i;
661	uint32_t count;
662	__be32 *p;
663	LIST_HEAD(extents);
664
665	dprintk("---> %s\n", __func__);
666
667	lseg = kzalloc(sizeof(*lseg), gfp_mask);
668	if (!lseg)
669		return ERR_PTR(-ENOMEM);
670
671	status = -ENOMEM;
672	scratch = alloc_page(gfp_mask);
673	if (!scratch)
674		goto out;
675
676	xdr_init_decode_pages(&xdr, &buf,
677			lgr->layoutp->pages, lgr->layoutp->len);
678	xdr_set_scratch_page(&xdr, scratch);
679
680	status = -EIO;
681	p = xdr_inline_decode(&xdr, 4);
682	if (unlikely(!p))
683		goto out_free_scratch;
684
685	count = be32_to_cpup(p++);
686	dprintk("%s: number of extents %d\n", __func__, count);
687
688	/*
689	 * Decode individual extents, putting them in temporary staging area
690	 * until whole layout is decoded to make error recovery easier.
691	 */
692	for (i = 0; i < count; i++) {
693		status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask);
694		if (status)
695			goto process_extents;
696	}
697
698	if (lgr->range.offset + lgr->range.length !=
699			lv.start << SECTOR_SHIFT) {
700		dprintk("%s Final length mismatch\n", __func__);
701		status = -EIO;
702		goto process_extents;
703	}
704
705	if (lv.start < lv.cowread) {
706		dprintk("%s Final uncovered COW extent\n", __func__);
707		status = -EIO;
708	}
709
710process_extents:
711	while (!list_empty(&extents)) {
712		struct pnfs_block_extent *be =
713			list_first_entry(&extents, struct pnfs_block_extent,
714					 be_list);
715		list_del(&be->be_list);
716
717		if (!status)
718			status = ext_tree_insert(bl, be);
719
720		if (status) {
721			nfs4_put_deviceid_node(be->be_device);
722			kfree(be);
723		}
724	}
725
726out_free_scratch:
727	__free_page(scratch);
728out:
729	dprintk("%s returns %d\n", __func__, status);
730	switch (status) {
731	case -ENODEV:
732		/* Our extent block devices are unavailable */
733		set_bit(NFS_LSEG_UNAVAILABLE, &lseg->pls_flags);
734		fallthrough;
735	case 0:
736		return lseg;
737	default:
738		kfree(lseg);
739		return ERR_PTR(status);
740	}
741}
742
743static void
744bl_return_range(struct pnfs_layout_hdr *lo,
745		struct pnfs_layout_range *range)
746{
747	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
748	sector_t offset = range->offset >> SECTOR_SHIFT, end;
749
750	if (range->offset % 8) {
751		dprintk("%s: offset %lld not block size aligned\n",
752			__func__, range->offset);
753		return;
754	}
755
756	if (range->length != NFS4_MAX_UINT64) {
757		if (range->length % 8) {
758			dprintk("%s: length %lld not block size aligned\n",
759				__func__, range->length);
760			return;
761		}
762
763		end = offset + (range->length >> SECTOR_SHIFT);
764	} else {
765		end = round_down(NFS4_MAX_UINT64, PAGE_SIZE);
766	}
767
768	ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end);
769}
770
771static int
772bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg)
773{
774	return ext_tree_prepare_commit(arg);
775}
776
777static void
778bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
779{
780	ext_tree_mark_committed(&lcdata->args, lcdata->res.status);
781}
782
783static int
784bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
785{
786	dprintk("%s enter\n", __func__);
787
788	if (server->pnfs_blksize == 0) {
789		dprintk("%s Server did not return blksize\n", __func__);
790		return -EINVAL;
791	}
792	if (server->pnfs_blksize > PAGE_SIZE) {
793		printk(KERN_ERR "%s: pNFS blksize %d not supported.\n",
794			__func__, server->pnfs_blksize);
795		return -EINVAL;
796	}
797
798	return 0;
799}
800
801static bool
802is_aligned_req(struct nfs_pageio_descriptor *pgio,
803		struct nfs_page *req, unsigned int alignment, bool is_write)
804{
805	/*
806	 * Always accept buffered writes, higher layers take care of the
807	 * right alignment.
808	 */
809	if (pgio->pg_dreq == NULL)
810		return true;
811
812	if (!IS_ALIGNED(req->wb_offset, alignment))
813		return false;
814
815	if (IS_ALIGNED(req->wb_bytes, alignment))
816		return true;
817
818	if (is_write &&
819	    (req_offset(req) + req->wb_bytes == i_size_read(pgio->pg_inode))) {
820		/*
821		 * If the write goes up to the inode size, just write
822		 * the full page.  Data past the inode size is
823		 * guaranteed to be zeroed by the higher level client
824		 * code, and this behaviour is mandated by RFC 5663
825		 * section 2.3.2.
826		 */
827		return true;
828	}
829
830	return false;
831}
832
833static void
834bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
835{
836	if (!is_aligned_req(pgio, req, SECTOR_SIZE, false)) {
837		nfs_pageio_reset_read_mds(pgio);
838		return;
839	}
840
841	pnfs_generic_pg_init_read(pgio, req);
842
843	if (pgio->pg_lseg &&
844		test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
845		pnfs_error_mark_layout_for_return(pgio->pg_inode, pgio->pg_lseg);
846		pnfs_set_lo_fail(pgio->pg_lseg);
847		nfs_pageio_reset_read_mds(pgio);
848	}
849}
850
851/*
852 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
853 * of bytes (maximum @req->wb_bytes) that can be coalesced.
854 */
855static size_t
856bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
857		struct nfs_page *req)
858{
859	if (!is_aligned_req(pgio, req, SECTOR_SIZE, false))
860		return 0;
861	return pnfs_generic_pg_test(pgio, prev, req);
862}
863
864/*
865 * Return the number of contiguous bytes for a given inode
866 * starting at page frame idx.
867 */
868static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
869{
870	struct address_space *mapping = inode->i_mapping;
871	pgoff_t end;
872
873	/* Optimize common case that writes from 0 to end of file */
874	end = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
875	if (end != inode->i_mapping->nrpages) {
876		rcu_read_lock();
877		end = page_cache_next_miss(mapping, idx + 1, ULONG_MAX);
878		rcu_read_unlock();
879	}
880
881	if (!end)
882		return i_size_read(inode) - (idx << PAGE_SHIFT);
883	else
884		return (end - idx) << PAGE_SHIFT;
885}
886
887static void
888bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
889{
890	u64 wb_size;
891
892	if (!is_aligned_req(pgio, req, PAGE_SIZE, true)) {
893		nfs_pageio_reset_write_mds(pgio);
894		return;
895	}
896
897	if (pgio->pg_dreq == NULL)
898		wb_size = pnfs_num_cont_bytes(pgio->pg_inode, req->wb_index);
899	else
900		wb_size = nfs_dreq_bytes_left(pgio->pg_dreq, req_offset(req));
901
902	pnfs_generic_pg_init_write(pgio, req, wb_size);
903
904	if (pgio->pg_lseg &&
905		test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
906
907		pnfs_error_mark_layout_for_return(pgio->pg_inode, pgio->pg_lseg);
908		pnfs_set_lo_fail(pgio->pg_lseg);
909		nfs_pageio_reset_write_mds(pgio);
910	}
911}
912
913/*
914 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
915 * of bytes (maximum @req->wb_bytes) that can be coalesced.
916 */
917static size_t
918bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
919		 struct nfs_page *req)
920{
921	if (!is_aligned_req(pgio, req, PAGE_SIZE, true))
922		return 0;
923	return pnfs_generic_pg_test(pgio, prev, req);
924}
925
926static const struct nfs_pageio_ops bl_pg_read_ops = {
927	.pg_init = bl_pg_init_read,
928	.pg_test = bl_pg_test_read,
929	.pg_doio = pnfs_generic_pg_readpages,
930	.pg_cleanup = pnfs_generic_pg_cleanup,
931};
932
933static const struct nfs_pageio_ops bl_pg_write_ops = {
934	.pg_init = bl_pg_init_write,
935	.pg_test = bl_pg_test_write,
936	.pg_doio = pnfs_generic_pg_writepages,
937	.pg_cleanup = pnfs_generic_pg_cleanup,
938};
939
940static struct pnfs_layoutdriver_type blocklayout_type = {
941	.id				= LAYOUT_BLOCK_VOLUME,
942	.name				= "LAYOUT_BLOCK_VOLUME",
943	.owner				= THIS_MODULE,
944	.flags				= PNFS_LAYOUTRET_ON_SETATTR |
945					  PNFS_LAYOUTRET_ON_ERROR |
946					  PNFS_READ_WHOLE_PAGE,
947	.read_pagelist			= bl_read_pagelist,
948	.write_pagelist			= bl_write_pagelist,
949	.alloc_layout_hdr		= bl_alloc_layout_hdr,
950	.free_layout_hdr		= bl_free_layout_hdr,
951	.alloc_lseg			= bl_alloc_lseg,
952	.free_lseg			= bl_free_lseg,
953	.return_range			= bl_return_range,
954	.prepare_layoutcommit		= bl_prepare_layoutcommit,
955	.cleanup_layoutcommit		= bl_cleanup_layoutcommit,
956	.set_layoutdriver		= bl_set_layoutdriver,
957	.alloc_deviceid_node		= bl_alloc_deviceid_node,
958	.free_deviceid_node		= bl_free_deviceid_node,
959	.pg_read_ops			= &bl_pg_read_ops,
960	.pg_write_ops			= &bl_pg_write_ops,
961	.sync				= pnfs_generic_sync,
962};
963
964static struct pnfs_layoutdriver_type scsilayout_type = {
965	.id				= LAYOUT_SCSI,
966	.name				= "LAYOUT_SCSI",
967	.owner				= THIS_MODULE,
968	.flags				= PNFS_LAYOUTRET_ON_SETATTR |
969					  PNFS_LAYOUTRET_ON_ERROR |
970					  PNFS_READ_WHOLE_PAGE,
971	.read_pagelist			= bl_read_pagelist,
972	.write_pagelist			= bl_write_pagelist,
973	.alloc_layout_hdr		= sl_alloc_layout_hdr,
974	.free_layout_hdr		= bl_free_layout_hdr,
975	.alloc_lseg			= bl_alloc_lseg,
976	.free_lseg			= bl_free_lseg,
977	.return_range			= bl_return_range,
978	.prepare_layoutcommit		= bl_prepare_layoutcommit,
979	.cleanup_layoutcommit		= bl_cleanup_layoutcommit,
980	.set_layoutdriver		= bl_set_layoutdriver,
981	.alloc_deviceid_node		= bl_alloc_deviceid_node,
982	.free_deviceid_node		= bl_free_deviceid_node,
983	.pg_read_ops			= &bl_pg_read_ops,
984	.pg_write_ops			= &bl_pg_write_ops,
985	.sync				= pnfs_generic_sync,
986};
987
988
989static int __init nfs4blocklayout_init(void)
990{
991	int ret;
992
993	dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__);
994
995	ret = bl_init_pipefs();
996	if (ret)
997		goto out;
998
999	ret = pnfs_register_layoutdriver(&blocklayout_type);
1000	if (ret)
1001		goto out_cleanup_pipe;
1002
1003	ret = pnfs_register_layoutdriver(&scsilayout_type);
1004	if (ret)
1005		goto out_unregister_block;
1006	return 0;
1007
1008out_unregister_block:
1009	pnfs_unregister_layoutdriver(&blocklayout_type);
1010out_cleanup_pipe:
1011	bl_cleanup_pipefs();
1012out:
1013	return ret;
1014}
1015
1016static void __exit nfs4blocklayout_exit(void)
1017{
1018	dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
1019	       __func__);
1020
1021	pnfs_unregister_layoutdriver(&scsilayout_type);
1022	pnfs_unregister_layoutdriver(&blocklayout_type);
1023	bl_cleanup_pipefs();
1024}
1025
1026MODULE_ALIAS("nfs-layouttype4-3");
1027MODULE_ALIAS("nfs-layouttype4-5");
1028
1029module_init(nfs4blocklayout_init);
1030module_exit(nfs4blocklayout_exit);
1031