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 return ERR_PTR(error: -ENODEV);
584}
585
586static int
587bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo,
588 struct layout_verification *lv, struct list_head *extents,
589 gfp_t gfp_mask)
590{
591 struct pnfs_block_extent *be;
592 struct nfs4_deviceid id;
593 int error;
594 __be32 *p;
595
596 p = xdr_inline_decode(xdr, nbytes: 28 + NFS4_DEVICEID4_SIZE);
597 if (!p)
598 return -EIO;
599
600 be = kzalloc(size: sizeof(*be), GFP_NOFS);
601 if (!be)
602 return -ENOMEM;
603
604 memcpy(&id, p, NFS4_DEVICEID4_SIZE);
605 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
606
607 be->be_device = bl_find_get_deviceid(server: NFS_SERVER(inode: lo->plh_inode), id: &id,
608 cred: lo->plh_lc_cred, gfp_mask);
609 if (IS_ERR(ptr: be->be_device)) {
610 error = PTR_ERR(ptr: be->be_device);
611 goto out_free_be;
612 }
613
614 /*
615 * The next three values are read in as bytes, but stored in the
616 * extent structure in 512-byte granularity.
617 */
618 error = -EIO;
619 if (decode_sector_number(rp: &p, sp: &be->be_f_offset) < 0)
620 goto out_put_deviceid;
621 if (decode_sector_number(rp: &p, sp: &be->be_length) < 0)
622 goto out_put_deviceid;
623 if (decode_sector_number(rp: &p, sp: &be->be_v_offset) < 0)
624 goto out_put_deviceid;
625 be->be_state = be32_to_cpup(p: p++);
626
627 error = verify_extent(be, lv);
628 if (error) {
629 dprintk("%s: extent verification failed\n", __func__);
630 goto out_put_deviceid;
631 }
632
633 list_add_tail(new: &be->be_list, head: extents);
634 return 0;
635
636out_put_deviceid:
637 nfs4_put_deviceid_node(be->be_device);
638out_free_be:
639 kfree(objp: be);
640 return error;
641}
642
643static struct pnfs_layout_segment *
644bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr,
645 gfp_t gfp_mask)
646{
647 struct layout_verification lv = {
648 .mode = lgr->range.iomode,
649 .start = lgr->range.offset >> SECTOR_SHIFT,
650 .inval = lgr->range.offset >> SECTOR_SHIFT,
651 .cowread = lgr->range.offset >> SECTOR_SHIFT,
652 };
653 struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
654 struct pnfs_layout_segment *lseg;
655 struct xdr_buf buf;
656 struct xdr_stream xdr;
657 struct page *scratch;
658 int status, i;
659 uint32_t count;
660 __be32 *p;
661 LIST_HEAD(extents);
662
663 dprintk("---> %s\n", __func__);
664
665 lseg = kzalloc(size: sizeof(*lseg), flags: gfp_mask);
666 if (!lseg)
667 return ERR_PTR(error: -ENOMEM);
668
669 status = -ENOMEM;
670 scratch = alloc_page(gfp_mask);
671 if (!scratch)
672 goto out;
673
674 xdr_init_decode_pages(xdr: &xdr, buf: &buf,
675 pages: lgr->layoutp->pages, len: lgr->layoutp->len);
676 xdr_set_scratch_page(xdr: &xdr, page: scratch);
677
678 status = -EIO;
679 p = xdr_inline_decode(xdr: &xdr, nbytes: 4);
680 if (unlikely(!p))
681 goto out_free_scratch;
682
683 count = be32_to_cpup(p: p++);
684 dprintk("%s: number of extents %d\n", __func__, count);
685
686 /*
687 * Decode individual extents, putting them in temporary staging area
688 * until whole layout is decoded to make error recovery easier.
689 */
690 for (i = 0; i < count; i++) {
691 status = bl_alloc_extent(xdr: &xdr, lo, lv: &lv, extents: &extents, gfp_mask);
692 if (status)
693 goto process_extents;
694 }
695
696 if (lgr->range.offset + lgr->range.length !=
697 lv.start << SECTOR_SHIFT) {
698 dprintk("%s Final length mismatch\n", __func__);
699 status = -EIO;
700 goto process_extents;
701 }
702
703 if (lv.start < lv.cowread) {
704 dprintk("%s Final uncovered COW extent\n", __func__);
705 status = -EIO;
706 }
707
708process_extents:
709 while (!list_empty(head: &extents)) {
710 struct pnfs_block_extent *be =
711 list_first_entry(&extents, struct pnfs_block_extent,
712 be_list);
713 list_del(entry: &be->be_list);
714
715 if (!status)
716 status = ext_tree_insert(bl, new: be);
717
718 if (status) {
719 nfs4_put_deviceid_node(be->be_device);
720 kfree(objp: be);
721 }
722 }
723
724out_free_scratch:
725 __free_page(scratch);
726out:
727 dprintk("%s returns %d\n", __func__, status);
728 switch (status) {
729 case -ENODEV:
730 /* Our extent block devices are unavailable */
731 set_bit(nr: NFS_LSEG_UNAVAILABLE, addr: &lseg->pls_flags);
732 fallthrough;
733 case 0:
734 return lseg;
735 default:
736 kfree(objp: lseg);
737 return ERR_PTR(error: status);
738 }
739}
740
741static void
742bl_return_range(struct pnfs_layout_hdr *lo,
743 struct pnfs_layout_range *range)
744{
745 struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
746 sector_t offset = range->offset >> SECTOR_SHIFT, end;
747
748 if (range->offset % 8) {
749 dprintk("%s: offset %lld not block size aligned\n",
750 __func__, range->offset);
751 return;
752 }
753
754 if (range->length != NFS4_MAX_UINT64) {
755 if (range->length % 8) {
756 dprintk("%s: length %lld not block size aligned\n",
757 __func__, range->length);
758 return;
759 }
760
761 end = offset + (range->length >> SECTOR_SHIFT);
762 } else {
763 end = round_down(NFS4_MAX_UINT64, PAGE_SIZE);
764 }
765
766 ext_tree_remove(bl, rw: range->iomode & IOMODE_RW, start: offset, end);
767}
768
769static int
770bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg)
771{
772 return ext_tree_prepare_commit(arg);
773}
774
775static void
776bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
777{
778 ext_tree_mark_committed(arg: &lcdata->args, status: lcdata->res.status);
779}
780
781static int
782bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
783{
784 dprintk("%s enter\n", __func__);
785
786 if (server->pnfs_blksize == 0) {
787 dprintk("%s Server did not return blksize\n", __func__);
788 return -EINVAL;
789 }
790 if (server->pnfs_blksize > PAGE_SIZE) {
791 printk(KERN_ERR "%s: pNFS blksize %d not supported.\n",
792 __func__, server->pnfs_blksize);
793 return -EINVAL;
794 }
795
796 return 0;
797}
798
799static bool
800is_aligned_req(struct nfs_pageio_descriptor *pgio,
801 struct nfs_page *req, unsigned int alignment, bool is_write)
802{
803 /*
804 * Always accept buffered writes, higher layers take care of the
805 * right alignment.
806 */
807 if (pgio->pg_dreq == NULL)
808 return true;
809
810 if (!IS_ALIGNED(req->wb_offset, alignment))
811 return false;
812
813 if (IS_ALIGNED(req->wb_bytes, alignment))
814 return true;
815
816 if (is_write &&
817 (req_offset(req) + req->wb_bytes == i_size_read(inode: pgio->pg_inode))) {
818 /*
819 * If the write goes up to the inode size, just write
820 * the full page. Data past the inode size is
821 * guaranteed to be zeroed by the higher level client
822 * code, and this behaviour is mandated by RFC 5663
823 * section 2.3.2.
824 */
825 return true;
826 }
827
828 return false;
829}
830
831static void
832bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
833{
834 if (!is_aligned_req(pgio, req, SECTOR_SIZE, is_write: false)) {
835 nfs_pageio_reset_read_mds(pgio);
836 return;
837 }
838
839 pnfs_generic_pg_init_read(pgio, req);
840
841 if (pgio->pg_lseg &&
842 test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
843 pnfs_error_mark_layout_for_return(inode: pgio->pg_inode, lseg: pgio->pg_lseg);
844 pnfs_set_lo_fail(lseg: pgio->pg_lseg);
845 nfs_pageio_reset_read_mds(pgio);
846 }
847}
848
849/*
850 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
851 * of bytes (maximum @req->wb_bytes) that can be coalesced.
852 */
853static size_t
854bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
855 struct nfs_page *req)
856{
857 if (!is_aligned_req(pgio, req, SECTOR_SIZE, is_write: false))
858 return 0;
859 return pnfs_generic_pg_test(pgio, prev, req);
860}
861
862/*
863 * Return the number of contiguous bytes for a given inode
864 * starting at page frame idx.
865 */
866static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
867{
868 struct address_space *mapping = inode->i_mapping;
869 pgoff_t end;
870
871 /* Optimize common case that writes from 0 to end of file */
872 end = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
873 if (end != inode->i_mapping->nrpages) {
874 rcu_read_lock();
875 end = page_cache_next_miss(mapping, index: idx + 1, ULONG_MAX);
876 rcu_read_unlock();
877 }
878
879 if (!end)
880 return i_size_read(inode) - (idx << PAGE_SHIFT);
881 else
882 return (end - idx) << PAGE_SHIFT;
883}
884
885static void
886bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
887{
888 u64 wb_size;
889
890 if (!is_aligned_req(pgio, req, PAGE_SIZE, is_write: true)) {
891 nfs_pageio_reset_write_mds(pgio);
892 return;
893 }
894
895 if (pgio->pg_dreq == NULL)
896 wb_size = pnfs_num_cont_bytes(inode: pgio->pg_inode,
897 idx: req->wb_index);
898 else
899 wb_size = nfs_dreq_bytes_left(dreq: pgio->pg_dreq);
900
901 pnfs_generic_pg_init_write(pgio, req, wb_size);
902
903 if (pgio->pg_lseg &&
904 test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
905
906 pnfs_error_mark_layout_for_return(inode: pgio->pg_inode, lseg: pgio->pg_lseg);
907 pnfs_set_lo_fail(lseg: pgio->pg_lseg);
908 nfs_pageio_reset_write_mds(pgio);
909 }
910}
911
912/*
913 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
914 * of bytes (maximum @req->wb_bytes) that can be coalesced.
915 */
916static size_t
917bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
918 struct nfs_page *req)
919{
920 if (!is_aligned_req(pgio, req, PAGE_SIZE, is_write: true))
921 return 0;
922 return pnfs_generic_pg_test(pgio, prev, req);
923}
924
925static const struct nfs_pageio_ops bl_pg_read_ops = {
926 .pg_init = bl_pg_init_read,
927 .pg_test = bl_pg_test_read,
928 .pg_doio = pnfs_generic_pg_readpages,
929 .pg_cleanup = pnfs_generic_pg_cleanup,
930};
931
932static const struct nfs_pageio_ops bl_pg_write_ops = {
933 .pg_init = bl_pg_init_write,
934 .pg_test = bl_pg_test_write,
935 .pg_doio = pnfs_generic_pg_writepages,
936 .pg_cleanup = pnfs_generic_pg_cleanup,
937};
938
939static struct pnfs_layoutdriver_type blocklayout_type = {
940 .id = LAYOUT_BLOCK_VOLUME,
941 .name = "LAYOUT_BLOCK_VOLUME",
942 .owner = THIS_MODULE,
943 .flags = PNFS_LAYOUTRET_ON_SETATTR |
944 PNFS_LAYOUTRET_ON_ERROR |
945 PNFS_READ_WHOLE_PAGE,
946 .read_pagelist = bl_read_pagelist,
947 .write_pagelist = bl_write_pagelist,
948 .alloc_layout_hdr = bl_alloc_layout_hdr,
949 .free_layout_hdr = bl_free_layout_hdr,
950 .alloc_lseg = bl_alloc_lseg,
951 .free_lseg = bl_free_lseg,
952 .return_range = bl_return_range,
953 .prepare_layoutcommit = bl_prepare_layoutcommit,
954 .cleanup_layoutcommit = bl_cleanup_layoutcommit,
955 .set_layoutdriver = bl_set_layoutdriver,
956 .alloc_deviceid_node = bl_alloc_deviceid_node,
957 .free_deviceid_node = bl_free_deviceid_node,
958 .pg_read_ops = &bl_pg_read_ops,
959 .pg_write_ops = &bl_pg_write_ops,
960 .sync = pnfs_generic_sync,
961};
962
963static struct pnfs_layoutdriver_type scsilayout_type = {
964 .id = LAYOUT_SCSI,
965 .name = "LAYOUT_SCSI",
966 .owner = THIS_MODULE,
967 .flags = PNFS_LAYOUTRET_ON_SETATTR |
968 PNFS_LAYOUTRET_ON_ERROR |
969 PNFS_READ_WHOLE_PAGE,
970 .read_pagelist = bl_read_pagelist,
971 .write_pagelist = bl_write_pagelist,
972 .alloc_layout_hdr = sl_alloc_layout_hdr,
973 .free_layout_hdr = bl_free_layout_hdr,
974 .alloc_lseg = bl_alloc_lseg,
975 .free_lseg = bl_free_lseg,
976 .return_range = bl_return_range,
977 .prepare_layoutcommit = bl_prepare_layoutcommit,
978 .cleanup_layoutcommit = bl_cleanup_layoutcommit,
979 .set_layoutdriver = bl_set_layoutdriver,
980 .alloc_deviceid_node = bl_alloc_deviceid_node,
981 .free_deviceid_node = bl_free_deviceid_node,
982 .pg_read_ops = &bl_pg_read_ops,
983 .pg_write_ops = &bl_pg_write_ops,
984 .sync = pnfs_generic_sync,
985};
986
987
988static int __init nfs4blocklayout_init(void)
989{
990 int ret;
991
992 dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__);
993
994 ret = bl_init_pipefs();
995 if (ret)
996 goto out;
997
998 ret = pnfs_register_layoutdriver(&blocklayout_type);
999 if (ret)
1000 goto out_cleanup_pipe;
1001
1002 ret = pnfs_register_layoutdriver(&scsilayout_type);
1003 if (ret)
1004 goto out_unregister_block;
1005 return 0;
1006
1007out_unregister_block:
1008 pnfs_unregister_layoutdriver(&blocklayout_type);
1009out_cleanup_pipe:
1010 bl_cleanup_pipefs();
1011out:
1012 return ret;
1013}
1014
1015static void __exit nfs4blocklayout_exit(void)
1016{
1017 dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
1018 __func__);
1019
1020 pnfs_unregister_layoutdriver(&scsilayout_type);
1021 pnfs_unregister_layoutdriver(&blocklayout_type);
1022 bl_cleanup_pipefs();
1023}
1024
1025MODULE_ALIAS("nfs-layouttype4-3");
1026MODULE_ALIAS("nfs-layouttype4-5");
1027
1028module_init(nfs4blocklayout_init);
1029module_exit(nfs4blocklayout_exit);
1030

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