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(size: sizeof(*rv), GFP_NOFS);
78 if (rv) {
79 rv->data = data;
80 kref_init(kref: &rv->refcnt);
81 }
82 return rv;
83}
84
85static inline void get_parallel(struct parallel_io *p)
86{
87 kref_get(kref: &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(objp: p);
97}
98
99static inline void put_parallel(struct parallel_io *p)
100{
101 kref_put(kref: &p->refcnt, release: destroy_parallel);
102}
103
104static struct bio *
105bl_submit_bio(struct bio *bio)
106{
107 if (bio) {
108 get_parallel(p: 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(offset: disk_addr, map)) {
143 if (!dev->map(dev, disk_addr, map) || !offset_in_map(offset: disk_addr, map))
144 return ERR_PTR(error: -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(bdev: map->bdev, nr_vecs: bio_max_segs(nr_segs: npg), opf: 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: *len, off: 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(lseg: 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, ret: &be, rw))
181 return;
182 extent_length = be.be_length - (isect - be.be_f_offset);
183 nfs4_mark_deviceid_unavailable(node: 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(lseg: header->lseg);
202 bl_mark_devices_unavailable(header, rw: false);
203 }
204
205 bio_put(bio);
206 put_parallel(p: 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(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(lseg: 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(data: 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, ret: &be, rw: 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: &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(page: pages[i], start: pg_offset, end: pg_len);
288
289 /* invalidate map */
290 map.start = NFS4_MAX_UINT64;
291 } else {
292 bio = do_add_page_to_bio(bio,
293 npg: header->page_array.npages - i,
294 op: REQ_OP_READ,
295 isect, page: pages[i], map: &map, be: &be,
296 end_io: bl_end_io_read, par,
297 offset: pg_offset, len: &pg_len);
298 if (IS_ERR(ptr: bio)) {
299 header->pnfs_error = PTR_ERR(ptr: 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(p: 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(lseg: header->lseg);
332 bl_mark_devices_unavailable(header, rw: true);
333 }
334 bio_put(bio);
335 put_parallel(p: 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(lseg: 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: start >> SECTOR_SHIFT,
357 len: (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(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(lseg: 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(data: 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, ret: &be, rw: 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, npg: header->page_array.npages - i,
423 op: REQ_OP_WRITE, isect, page: pages[i], map: &map,
424 be: &be, end_io: bl_end_io_write, par, offset: 0, len: &pg_len);
425 if (IS_ERR(ptr: bio)) {
426 header->pnfs_error = PTR_ERR(ptr: 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(p: 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, rw: true, start: 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(size: sizeof(*bl), flags: 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, is_scsi_layout: 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, is_scsi_layout: true);
486}
487
488static void bl_free_lseg(struct pnfs_layout_segment *lseg)
489{
490 dprintk("%s enter\n", __func__);
491 kfree(objp: 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(p: *rp, valp: &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(error: -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(error: -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, nbytes: 28 + NFS4_DEVICEID4_SIZE);
599 if (!p)
600 return -EIO;
601
602 be = kzalloc(size: 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(server: NFS_SERVER(inode: lo->plh_inode), id: &id,
610 cred: lo->plh_lc_cred, gfp_mask);
611 if (IS_ERR(ptr: be->be_device)) {
612 error = PTR_ERR(ptr: 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(rp: &p, sp: &be->be_f_offset) < 0)
622 goto out_put_deviceid;
623 if (decode_sector_number(rp: &p, sp: &be->be_length) < 0)
624 goto out_put_deviceid;
625 if (decode_sector_number(rp: &p, sp: &be->be_v_offset) < 0)
626 goto out_put_deviceid;
627 be->be_state = be32_to_cpup(p: 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(new: &be->be_list, head: extents);
636 return 0;
637
638out_put_deviceid:
639 nfs4_put_deviceid_node(be->be_device);
640out_free_be:
641 kfree(objp: 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(size: sizeof(*lseg), flags: gfp_mask);
668 if (!lseg)
669 return ERR_PTR(error: -ENOMEM);
670
671 status = -ENOMEM;
672 scratch = alloc_page(gfp_mask);
673 if (!scratch)
674 goto out;
675
676 xdr_init_decode_pages(xdr: &xdr, buf: &buf,
677 pages: lgr->layoutp->pages, len: lgr->layoutp->len);
678 xdr_set_scratch_page(xdr: &xdr, page: scratch);
679
680 status = -EIO;
681 p = xdr_inline_decode(xdr: &xdr, nbytes: 4);
682 if (unlikely(!p))
683 goto out_free_scratch;
684
685 count = be32_to_cpup(p: 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: &xdr, lo, lv: &lv, extents: &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(head: &extents)) {
712 struct pnfs_block_extent *be =
713 list_first_entry(&extents, struct pnfs_block_extent,
714 be_list);
715 list_del(entry: &be->be_list);
716
717 if (!status)
718 status = ext_tree_insert(bl, new: be);
719
720 if (status) {
721 nfs4_put_deviceid_node(be->be_device);
722 kfree(objp: 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(nr: NFS_LSEG_UNAVAILABLE, addr: &lseg->pls_flags);
734 fallthrough;
735 case 0:
736 return lseg;
737 default:
738 kfree(objp: lseg);
739 return ERR_PTR(error: 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, rw: range->iomode & IOMODE_RW, start: 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(arg: &lcdata->args, status: 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(inode: 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, is_write: 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(inode: pgio->pg_inode, lseg: pgio->pg_lseg);
846 pnfs_set_lo_fail(lseg: 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, is_write: 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, index: 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, is_write: 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(inode: pgio->pg_inode, idx: req->wb_index);
899 else
900 wb_size = nfs_dreq_bytes_left(dreq: pgio->pg_dreq, offset: 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(inode: pgio->pg_inode, lseg: pgio->pg_lseg);
908 pnfs_set_lo_fail(lseg: 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, is_write: 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

source code of linux/fs/nfs/blocklayout/blocklayout.c