xref: /openbmc/linux/fs/nfs/blocklayout/blocklayout.c (revision 75aa038d)
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 
48 MODULE_LICENSE("GPL");
49 MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>");
50 MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
51 
is_hole(struct pnfs_block_extent * be)52 static 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  */
67 struct parallel_io {
68 	struct kref refcnt;
69 	void (*pnfs_callback) (void *data);
70 	void *data;
71 };
72 
alloc_parallel(void * data)73 static 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 
get_parallel(struct parallel_io * p)85 static inline void get_parallel(struct parallel_io *p)
86 {
87 	kref_get(&p->refcnt);
88 }
89 
destroy_parallel(struct kref * kref)90 static 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 
put_parallel(struct parallel_io * p)99 static inline void put_parallel(struct parallel_io *p)
100 {
101 	kref_put(&p->refcnt, destroy_parallel);
102 }
103 
104 static struct bio *
bl_submit_bio(struct bio * bio)105 bl_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 
offset_in_map(u64 offset,struct pnfs_block_dev_map * map)118 static 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 
123 static struct bio *
do_add_page_to_bio(struct bio * bio,int npg,enum req_op op,sector_t isect,struct page * page,struct pnfs_block_dev_map * map,struct pnfs_block_extent * be,bio_end_io_t end_io,struct parallel_io * par,unsigned int offset,int * len)124 do_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 
155 retry:
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 
bl_mark_devices_unavailable(struct nfs_pgio_header * header,bool rw)169 static 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 
bl_end_io_read(struct bio * bio)192 static 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 
bl_read_cleanup(struct work_struct * work)209 static 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 
219 static void
bl_end_par_io_read(void * data)220 bl_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 
229 static enum pnfs_try_status
bl_read_pagelist(struct nfs_pgio_header * header)230 bl_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 	}
316 out:
317 	bl_submit_bio(bio);
318 	blk_finish_plug(&plug);
319 	put_parallel(par);
320 	return PNFS_ATTEMPTED;
321 }
322 
bl_end_io_write(struct bio * bio)323 static 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  */
bl_write_cleanup(struct work_struct * work)341 static 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 */
bl_end_par_io_write(void * data)364 static 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 
374 static enum pnfs_try_status
bl_write_pagelist(struct nfs_pgio_header * header,int sync)375 bl_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;
438 out:
439 	bl_submit_bio(bio);
440 	blk_finish_plug(&plug);
441 	put_parallel(par);
442 	return PNFS_ATTEMPTED;
443 }
444 
bl_free_layout_hdr(struct pnfs_layout_hdr * lo)445 static 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 
__bl_alloc_layout_hdr(struct inode * inode,gfp_t gfp_flags,bool is_scsi_layout)458 static 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 
bl_alloc_layout_hdr(struct inode * inode,gfp_t gfp_flags)476 static 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 
sl_alloc_layout_hdr(struct inode * inode,gfp_t gfp_flags)482 static 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 
bl_free_lseg(struct pnfs_layout_segment * lseg)488 static 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 */
495 struct 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  */
verify_extent(struct pnfs_block_extent * be,struct layout_verification * lv)505 static 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 
decode_sector_number(__be32 ** rp,sector_t * sp)548 static 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 
561 static struct nfs4_deviceid_node *
bl_find_get_deviceid(struct nfs_server * server,const struct nfs4_deviceid * id,const struct cred * cred,gfp_t gfp_mask)562 bl_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 
569 retry:
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 
588 static int
bl_alloc_extent(struct xdr_stream * xdr,struct pnfs_layout_hdr * lo,struct layout_verification * lv,struct list_head * extents,gfp_t gfp_mask)589 bl_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 
638 out_put_deviceid:
639 	nfs4_put_deviceid_node(be->be_device);
640 out_free_be:
641 	kfree(be);
642 	return error;
643 }
644 
645 static struct pnfs_layout_segment *
bl_alloc_lseg(struct pnfs_layout_hdr * lo,struct nfs4_layoutget_res * lgr,gfp_t gfp_mask)646 bl_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 
710 process_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 
726 out_free_scratch:
727 	__free_page(scratch);
728 out:
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 
743 static void
bl_return_range(struct pnfs_layout_hdr * lo,struct pnfs_layout_range * range)744 bl_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 
771 static int
bl_prepare_layoutcommit(struct nfs4_layoutcommit_args * arg)772 bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg)
773 {
774 	return ext_tree_prepare_commit(arg);
775 }
776 
777 static void
bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data * lcdata)778 bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
779 {
780 	ext_tree_mark_committed(&lcdata->args, lcdata->res.status);
781 }
782 
783 static int
bl_set_layoutdriver(struct nfs_server * server,const struct nfs_fh * fh)784 bl_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 
801 static bool
is_aligned_req(struct nfs_pageio_descriptor * pgio,struct nfs_page * req,unsigned int alignment,bool is_write)802 is_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 
833 static void
bl_pg_init_read(struct nfs_pageio_descriptor * pgio,struct nfs_page * req)834 bl_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  */
855 static size_t
bl_pg_test_read(struct nfs_pageio_descriptor * pgio,struct nfs_page * prev,struct nfs_page * req)856 bl_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  */
pnfs_num_cont_bytes(struct inode * inode,pgoff_t idx)868 static 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 
887 static void
bl_pg_init_write(struct nfs_pageio_descriptor * pgio,struct nfs_page * req)888 bl_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  */
917 static size_t
bl_pg_test_write(struct nfs_pageio_descriptor * pgio,struct nfs_page * prev,struct nfs_page * req)918 bl_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 
926 static 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 
933 static 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 
940 static 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 
964 static 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 
nfs4blocklayout_init(void)989 static 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 
1008 out_unregister_block:
1009 	pnfs_unregister_layoutdriver(&blocklayout_type);
1010 out_cleanup_pipe:
1011 	bl_cleanup_pipefs();
1012 out:
1013 	return ret;
1014 }
1015 
nfs4blocklayout_exit(void)1016 static 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 
1026 MODULE_ALIAS("nfs-layouttype4-3");
1027 MODULE_ALIAS("nfs-layouttype4-5");
1028 
1029 module_init(nfs4blocklayout_init);
1030 module_exit(nfs4blocklayout_exit);
1031