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usb: gadget: udc: pch_udc: Fix a plethora of function documentation related issues
[linux/fpc-iii.git] / fs / nfs / blocklayout / blocklayout.c
blobd1a0e2c8b1b486bd2866b388fce595f036abe58b
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
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
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
85 static inline void get_parallel(struct parallel_io *p)
86 {
87 kref_get(&p->refcnt);
88 }
89
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
99 static inline void put_parallel(struct parallel_io *p)
100 {
101 kref_put(&p->refcnt, destroy_parallel);
102 }
103
104 static struct 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
118 static struct bio *
119 bl_alloc_init_bio(int npg, struct block_device *bdev, sector_t disk_sector,
120 bio_end_io_t end_io, struct parallel_io *par)
121 {
122 struct bio *bio;
123
124 npg = min(npg, BIO_MAX_PAGES);
125 bio = bio_alloc(GFP_NOIO, npg);
126 if (!bio && (current->flags & PF_MEMALLOC)) {
127 while (!bio && (npg /= 2))
128 bio = bio_alloc(GFP_NOIO, npg);
129 }
130
131 if (bio) {
132 bio->bi_iter.bi_sector = disk_sector;
133 bio_set_dev(bio, bdev);
134 bio->bi_end_io = end_io;
135 bio->bi_private = par;
136 }
137 return bio;
138 }
139
140 static bool offset_in_map(u64 offset, struct pnfs_block_dev_map *map)
141 {
142 return offset >= map->start && offset < map->start + map->len;
143 }
144
145 static struct bio *
146 do_add_page_to_bio(struct bio *bio, int npg, int rw, sector_t isect,
147 struct page *page, struct pnfs_block_dev_map *map,
148 struct pnfs_block_extent *be, bio_end_io_t end_io,
149 struct parallel_io *par, unsigned int offset, int *len)
150 {
151 struct pnfs_block_dev *dev =
152 container_of(be->be_device, struct pnfs_block_dev, node);
153 u64 disk_addr, end;
154
155 dprintk("%s: npg %d rw %d isect %llu offset %u len %d\n", __func__,
156 npg, rw, (unsigned long long)isect, offset, *len);
157
158 /* translate to device offset */
159 isect += be->be_v_offset;
160 isect -= be->be_f_offset;
161
162 /* translate to physical disk offset */
163 disk_addr = (u64)isect << SECTOR_SHIFT;
164 if (!offset_in_map(disk_addr, map)) {
165 if (!dev->map(dev, disk_addr, map) || !offset_in_map(disk_addr, map))
166 return ERR_PTR(-EIO);
167 bio = bl_submit_bio(bio);
168 }
169 disk_addr += map->disk_offset;
170 disk_addr -= map->start;
171
172 /* limit length to what the device mapping allows */
173 end = disk_addr + *len;
174 if (end >= map->start + map->len)
175 *len = map->start + map->len - disk_addr;
176
177 retry:
178 if (!bio) {
179 bio = bl_alloc_init_bio(npg, map->bdev,
180 disk_addr >> SECTOR_SHIFT, end_io, par);
181 if (!bio)
182 return ERR_PTR(-ENOMEM);
183 bio_set_op_attrs(bio, rw, 0);
184 }
185 if (bio_add_page(bio, page, *len, offset) < *len) {
186 bio = bl_submit_bio(bio);
187 goto retry;
188 }
189 return bio;
190 }
191
192 static void bl_mark_devices_unavailable(struct nfs_pgio_header *header, bool rw)
193 {
194 struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
195 size_t bytes_left = header->args.count;
196 sector_t isect, extent_length = 0;
197 struct pnfs_block_extent be;
198
199 isect = header->args.offset >> SECTOR_SHIFT;
200 bytes_left += header->args.offset - (isect << SECTOR_SHIFT);
201
202 while (bytes_left > 0) {
203 if (!ext_tree_lookup(bl, isect, &be, rw))
204 return;
205 extent_length = be.be_length - (isect - be.be_f_offset);
206 nfs4_mark_deviceid_unavailable(be.be_device);
207 isect += extent_length;
208 if (bytes_left > extent_length << SECTOR_SHIFT)
209 bytes_left -= extent_length << SECTOR_SHIFT;
210 else
211 bytes_left = 0;
212 }
213 }
214
215 static void bl_end_io_read(struct bio *bio)
216 {
217 struct parallel_io *par = bio->bi_private;
218
219 if (bio->bi_status) {
220 struct nfs_pgio_header *header = par->data;
221
222 if (!header->pnfs_error)
223 header->pnfs_error = -EIO;
224 pnfs_set_lo_fail(header->lseg);
225 bl_mark_devices_unavailable(header, false);
226 }
227
228 bio_put(bio);
229 put_parallel(par);
230 }
231
232 static void bl_read_cleanup(struct work_struct *work)
233 {
234 struct rpc_task *task;
235 struct nfs_pgio_header *hdr;
236 dprintk("%s enter\n", __func__);
237 task = container_of(work, struct rpc_task, u.tk_work);
238 hdr = container_of(task, struct nfs_pgio_header, task);
239 pnfs_ld_read_done(hdr);
240 }
241
242 static void
243 bl_end_par_io_read(void *data)
244 {
245 struct nfs_pgio_header *hdr = data;
246
247 hdr->task.tk_status = hdr->pnfs_error;
248 INIT_WORK(&hdr->task.u.tk_work, bl_read_cleanup);
249 schedule_work(&hdr->task.u.tk_work);
250 }
251
252 static enum pnfs_try_status
253 bl_read_pagelist(struct nfs_pgio_header *header)
254 {
255 struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
256 struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
257 struct bio *bio = NULL;
258 struct pnfs_block_extent be;
259 sector_t isect, extent_length = 0;
260 struct parallel_io *par;
261 loff_t f_offset = header->args.offset;
262 size_t bytes_left = header->args.count;
263 unsigned int pg_offset = header->args.pgbase, pg_len;
264 struct page **pages = header->args.pages;
265 int pg_index = header->args.pgbase >> PAGE_SHIFT;
266 const bool is_dio = (header->dreq != NULL);
267 struct blk_plug plug;
268 int i;
269
270 dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__,
271 header->page_array.npages, f_offset,
272 (unsigned int)header->args.count);
273
274 par = alloc_parallel(header);
275 if (!par)
276 return PNFS_NOT_ATTEMPTED;
277 par->pnfs_callback = bl_end_par_io_read;
278
279 blk_start_plug(&plug);
280
281 isect = (sector_t) (f_offset >> SECTOR_SHIFT);
282 /* Code assumes extents are page-aligned */
283 for (i = pg_index; i < header->page_array.npages; i++) {
284 if (extent_length <= 0) {
285 /* We've used up the previous extent */
286 bio = bl_submit_bio(bio);
287
288 /* Get the next one */
289 if (!ext_tree_lookup(bl, isect, &be, false)) {
290 header->pnfs_error = -EIO;
291 goto out;
292 }
293 extent_length = be.be_length - (isect - be.be_f_offset);
294 }
295
296 if (is_dio) {
297 if (pg_offset + bytes_left > PAGE_SIZE)
298 pg_len = PAGE_SIZE - pg_offset;
299 else
300 pg_len = bytes_left;
301 } else {
302 BUG_ON(pg_offset != 0);
303 pg_len = PAGE_SIZE;
304 }
305
306 if (is_hole(&be)) {
307 bio = bl_submit_bio(bio);
308 /* Fill hole w/ zeroes w/o accessing device */
309 dprintk("%s Zeroing page for hole\n", __func__);
310 zero_user_segment(pages[i], pg_offset, pg_len);
311
312 /* invalidate map */
313 map.start = NFS4_MAX_UINT64;
314 } else {
315 bio = do_add_page_to_bio(bio,
316 header->page_array.npages - i,
317 READ,
318 isect, pages[i], &map, &be,
319 bl_end_io_read, par,
320 pg_offset, &pg_len);
321 if (IS_ERR(bio)) {
322 header->pnfs_error = PTR_ERR(bio);
323 bio = NULL;
324 goto out;
325 }
326 }
327 isect += (pg_len >> SECTOR_SHIFT);
328 extent_length -= (pg_len >> SECTOR_SHIFT);
329 f_offset += pg_len;
330 bytes_left -= pg_len;
331 pg_offset = 0;
332 }
333 if ((isect << SECTOR_SHIFT) >= header->inode->i_size) {
334 header->res.eof = 1;
335 header->res.count = header->inode->i_size - header->args.offset;
336 } else {
337 header->res.count = (isect << SECTOR_SHIFT) - header->args.offset;
338 }
339 out:
340 bl_submit_bio(bio);
341 blk_finish_plug(&plug);
342 put_parallel(par);
343 return PNFS_ATTEMPTED;
344 }
345
346 static void bl_end_io_write(struct bio *bio)
347 {
348 struct parallel_io *par = bio->bi_private;
349 struct nfs_pgio_header *header = par->data;
350
351 if (bio->bi_status) {
352 if (!header->pnfs_error)
353 header->pnfs_error = -EIO;
354 pnfs_set_lo_fail(header->lseg);
355 bl_mark_devices_unavailable(header, true);
356 }
357 bio_put(bio);
358 put_parallel(par);
359 }
360
361 /* Function scheduled for call during bl_end_par_io_write,
362 * it marks sectors as written and extends the commitlist.
363 */
364 static void bl_write_cleanup(struct work_struct *work)
365 {
366 struct rpc_task *task = container_of(work, struct rpc_task, u.tk_work);
367 struct nfs_pgio_header *hdr =
368 container_of(task, struct nfs_pgio_header, task);
369
370 dprintk("%s enter\n", __func__);
371
372 if (likely(!hdr->pnfs_error)) {
373 struct pnfs_block_layout *bl = BLK_LSEG2EXT(hdr->lseg);
374 u64 start = hdr->args.offset & (loff_t)PAGE_MASK;
375 u64 end = (hdr->args.offset + hdr->args.count +
376 PAGE_SIZE - 1) & (loff_t)PAGE_MASK;
377 u64 lwb = hdr->args.offset + hdr->args.count;
378
379 ext_tree_mark_written(bl, start >> SECTOR_SHIFT,
380 (end - start) >> SECTOR_SHIFT, lwb);
381 }
382
383 pnfs_ld_write_done(hdr);
384 }
385
386 /* Called when last of bios associated with a bl_write_pagelist call finishes */
387 static void bl_end_par_io_write(void *data)
388 {
389 struct nfs_pgio_header *hdr = data;
390
391 hdr->task.tk_status = hdr->pnfs_error;
392 hdr->verf.committed = NFS_FILE_SYNC;
393 INIT_WORK(&hdr->task.u.tk_work, bl_write_cleanup);
394 schedule_work(&hdr->task.u.tk_work);
395 }
396
397 static enum pnfs_try_status
398 bl_write_pagelist(struct nfs_pgio_header *header, int sync)
399 {
400 struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
401 struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
402 struct bio *bio = NULL;
403 struct pnfs_block_extent be;
404 sector_t isect, extent_length = 0;
405 struct parallel_io *par = NULL;
406 loff_t offset = header->args.offset;
407 size_t count = header->args.count;
408 struct page **pages = header->args.pages;
409 int pg_index = header->args.pgbase >> PAGE_SHIFT;
410 unsigned int pg_len;
411 struct blk_plug plug;
412 int i;
413
414 dprintk("%s enter, %zu@%lld\n", __func__, count, offset);
415
416 /* At this point, header->page_aray is a (sequential) list of nfs_pages.
417 * We want to write each, and if there is an error set pnfs_error
418 * to have it redone using nfs.
419 */
420 par = alloc_parallel(header);
421 if (!par)
422 return PNFS_NOT_ATTEMPTED;
423 par->pnfs_callback = bl_end_par_io_write;
424
425 blk_start_plug(&plug);
426
427 /* we always write out the whole page */
428 offset = offset & (loff_t)PAGE_MASK;
429 isect = offset >> SECTOR_SHIFT;
430
431 for (i = pg_index; i < header->page_array.npages; i++) {
432 if (extent_length <= 0) {
433 /* We've used up the previous extent */
434 bio = bl_submit_bio(bio);
435 /* Get the next one */
436 if (!ext_tree_lookup(bl, isect, &be, true)) {
437 header->pnfs_error = -EINVAL;
438 goto out;
439 }
440
441 extent_length = be.be_length - (isect - be.be_f_offset);
442 }
443
444 pg_len = PAGE_SIZE;
445 bio = do_add_page_to_bio(bio, header->page_array.npages - i,
446 WRITE, isect, pages[i], &map, &be,
447 bl_end_io_write, par,
448 0, &pg_len);
449 if (IS_ERR(bio)) {
450 header->pnfs_error = PTR_ERR(bio);
451 bio = NULL;
452 goto out;
453 }
454
455 offset += pg_len;
456 count -= pg_len;
457 isect += (pg_len >> SECTOR_SHIFT);
458 extent_length -= (pg_len >> SECTOR_SHIFT);
459 }
460
461 header->res.count = header->args.count;
462 out:
463 bl_submit_bio(bio);
464 blk_finish_plug(&plug);
465 put_parallel(par);
466 return PNFS_ATTEMPTED;
467 }
468
469 static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo)
470 {
471 struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
472 int err;
473
474 dprintk("%s enter\n", __func__);
475
476 err = ext_tree_remove(bl, true, 0, LLONG_MAX);
477 WARN_ON(err);
478
479 kfree_rcu(bl, bl_layout.plh_rcu);
480 }
481
482 static struct pnfs_layout_hdr *__bl_alloc_layout_hdr(struct inode *inode,
483 gfp_t gfp_flags, bool is_scsi_layout)
484 {
485 struct pnfs_block_layout *bl;
486
487 dprintk("%s enter\n", __func__);
488 bl = kzalloc(sizeof(*bl), gfp_flags);
489 if (!bl)
490 return NULL;
491
492 bl->bl_ext_rw = RB_ROOT;
493 bl->bl_ext_ro = RB_ROOT;
494 spin_lock_init(&bl->bl_ext_lock);
495
496 bl->bl_scsi_layout = is_scsi_layout;
497 return &bl->bl_layout;
498 }
499
500 static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode,
501 gfp_t gfp_flags)
502 {
503 return __bl_alloc_layout_hdr(inode, gfp_flags, false);
504 }
505
506 static struct pnfs_layout_hdr *sl_alloc_layout_hdr(struct inode *inode,
507 gfp_t gfp_flags)
508 {
509 return __bl_alloc_layout_hdr(inode, gfp_flags, true);
510 }
511
512 static void bl_free_lseg(struct pnfs_layout_segment *lseg)
513 {
514 dprintk("%s enter\n", __func__);
515 kfree(lseg);
516 }
517
518 /* Tracks info needed to ensure extents in layout obey constraints of spec */
519 struct layout_verification {
520 u32 mode; /* R or RW */
521 u64 start; /* Expected start of next non-COW extent */
522 u64 inval; /* Start of INVAL coverage */
523 u64 cowread; /* End of COW read coverage */
524 };
525
526 /* Verify the extent meets the layout requirements of the pnfs-block draft,
527 * section 2.3.1.
528 */
529 static int verify_extent(struct pnfs_block_extent *be,
530 struct layout_verification *lv)
531 {
532 if (lv->mode == IOMODE_READ) {
533 if (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
534 be->be_state == PNFS_BLOCK_INVALID_DATA)
535 return -EIO;
536 if (be->be_f_offset != lv->start)
537 return -EIO;
538 lv->start += be->be_length;
539 return 0;
540 }
541 /* lv->mode == IOMODE_RW */
542 if (be->be_state == PNFS_BLOCK_READWRITE_DATA) {
543 if (be->be_f_offset != lv->start)
544 return -EIO;
545 if (lv->cowread > lv->start)
546 return -EIO;
547 lv->start += be->be_length;
548 lv->inval = lv->start;
549 return 0;
550 } else if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
551 if (be->be_f_offset != lv->start)
552 return -EIO;
553 lv->start += be->be_length;
554 return 0;
555 } else if (be->be_state == PNFS_BLOCK_READ_DATA) {
556 if (be->be_f_offset > lv->start)
557 return -EIO;
558 if (be->be_f_offset < lv->inval)
559 return -EIO;
560 if (be->be_f_offset < lv->cowread)
561 return -EIO;
562 /* It looks like you might want to min this with lv->start,
563 * but you really don't.
564 */
565 lv->inval = lv->inval + be->be_length;
566 lv->cowread = be->be_f_offset + be->be_length;
567 return 0;
568 } else
569 return -EIO;
570 }
571
572 static int decode_sector_number(__be32 **rp, sector_t *sp)
573 {
574 uint64_t s;
575
576 *rp = xdr_decode_hyper(*rp, &s);
577 if (s & 0x1ff) {
578 printk(KERN_WARNING "NFS: %s: sector not aligned\n", __func__);
579 return -1;
580 }
581 *sp = s >> SECTOR_SHIFT;
582 return 0;
583 }
584
585 static struct nfs4_deviceid_node *
586 bl_find_get_deviceid(struct nfs_server *server,
587 const struct nfs4_deviceid *id, const struct cred *cred,
588 gfp_t gfp_mask)
589 {
590 struct nfs4_deviceid_node *node;
591 unsigned long start, end;
592
593 retry:
594 node = nfs4_find_get_deviceid(server, id, cred, gfp_mask);
595 if (!node)
596 return ERR_PTR(-ENODEV);
597
598 if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags) == 0)
599 return node;
600
601 end = jiffies;
602 start = end - PNFS_DEVICE_RETRY_TIMEOUT;
603 if (!time_in_range(node->timestamp_unavailable, start, end)) {
604 nfs4_delete_deviceid(node->ld, node->nfs_client, id);
605 goto retry;
606 }
607 return ERR_PTR(-ENODEV);
608 }
609
610 static int
611 bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo,
612 struct layout_verification *lv, struct list_head *extents,
613 gfp_t gfp_mask)
614 {
615 struct pnfs_block_extent *be;
616 struct nfs4_deviceid id;
617 int error;
618 __be32 *p;
619
620 p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE);
621 if (!p)
622 return -EIO;
623
624 be = kzalloc(sizeof(*be), GFP_NOFS);
625 if (!be)
626 return -ENOMEM;
627
628 memcpy(&id, p, NFS4_DEVICEID4_SIZE);
629 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
630
631 be->be_device = bl_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id,
632 lo->plh_lc_cred, gfp_mask);
633 if (IS_ERR(be->be_device)) {
634 error = PTR_ERR(be->be_device);
635 goto out_free_be;
636 }
637
638 /*
639 * The next three values are read in as bytes, but stored in the
640 * extent structure in 512-byte granularity.
641 */
642 error = -EIO;
643 if (decode_sector_number(&p, &be->be_f_offset) < 0)
644 goto out_put_deviceid;
645 if (decode_sector_number(&p, &be->be_length) < 0)
646 goto out_put_deviceid;
647 if (decode_sector_number(&p, &be->be_v_offset) < 0)
648 goto out_put_deviceid;
649 be->be_state = be32_to_cpup(p++);
650
651 error = verify_extent(be, lv);
652 if (error) {
653 dprintk("%s: extent verification failed\n", __func__);
654 goto out_put_deviceid;
655 }
656
657 list_add_tail(&be->be_list, extents);
658 return 0;
659
660 out_put_deviceid:
661 nfs4_put_deviceid_node(be->be_device);
662 out_free_be:
663 kfree(be);
664 return error;
665 }
666
667 static struct pnfs_layout_segment *
668 bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr,
669 gfp_t gfp_mask)
670 {
671 struct layout_verification lv = {
672 .mode = lgr->range.iomode,
673 .start = lgr->range.offset >> SECTOR_SHIFT,
674 .inval = lgr->range.offset >> SECTOR_SHIFT,
675 .cowread = lgr->range.offset >> SECTOR_SHIFT,
676 };
677 struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
678 struct pnfs_layout_segment *lseg;
679 struct xdr_buf buf;
680 struct xdr_stream xdr;
681 struct page *scratch;
682 int status, i;
683 uint32_t count;
684 __be32 *p;
685 LIST_HEAD(extents);
686
687 dprintk("---> %s\n", __func__);
688
689 lseg = kzalloc(sizeof(*lseg), gfp_mask);
690 if (!lseg)
691 return ERR_PTR(-ENOMEM);
692
693 status = -ENOMEM;
694 scratch = alloc_page(gfp_mask);
695 if (!scratch)
696 goto out;
697
698 xdr_init_decode_pages(&xdr, &buf,
699 lgr->layoutp->pages, lgr->layoutp->len);
700 xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);
701
702 status = -EIO;
703 p = xdr_inline_decode(&xdr, 4);
704 if (unlikely(!p))
705 goto out_free_scratch;
706
707 count = be32_to_cpup(p++);
708 dprintk("%s: number of extents %d\n", __func__, count);
709
710 /*
711 * Decode individual extents, putting them in temporary staging area
712 * until whole layout is decoded to make error recovery easier.
713 */
714 for (i = 0; i < count; i++) {
715 status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask);
716 if (status)
717 goto process_extents;
718 }
719
720 if (lgr->range.offset + lgr->range.length !=
721 lv.start << SECTOR_SHIFT) {
722 dprintk("%s Final length mismatch\n", __func__);
723 status = -EIO;
724 goto process_extents;
725 }
726
727 if (lv.start < lv.cowread) {
728 dprintk("%s Final uncovered COW extent\n", __func__);
729 status = -EIO;
730 }
731
732 process_extents:
733 while (!list_empty(&extents)) {
734 struct pnfs_block_extent *be =
735 list_first_entry(&extents, struct pnfs_block_extent,
736 be_list);
737 list_del(&be->be_list);
738
739 if (!status)
740 status = ext_tree_insert(bl, be);
741
742 if (status) {
743 nfs4_put_deviceid_node(be->be_device);
744 kfree(be);
745 }
746 }
747
748 out_free_scratch:
749 __free_page(scratch);
750 out:
751 dprintk("%s returns %d\n", __func__, status);
752 switch (status) {
753 case -ENODEV:
754 /* Our extent block devices are unavailable */
755 set_bit(NFS_LSEG_UNAVAILABLE, &lseg->pls_flags);
756 /* Fall through */
757 case 0:
758 return lseg;
759 default:
760 kfree(lseg);
761 return ERR_PTR(status);
762 }
763 }
764
765 static void
766 bl_return_range(struct pnfs_layout_hdr *lo,
767 struct pnfs_layout_range *range)
768 {
769 struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
770 sector_t offset = range->offset >> SECTOR_SHIFT, end;
771
772 if (range->offset % 8) {
773 dprintk("%s: offset %lld not block size aligned\n",
774 __func__, range->offset);
775 return;
776 }
777
778 if (range->length != NFS4_MAX_UINT64) {
779 if (range->length % 8) {
780 dprintk("%s: length %lld not block size aligned\n",
781 __func__, range->length);
782 return;
783 }
784
785 end = offset + (range->length >> SECTOR_SHIFT);
786 } else {
787 end = round_down(NFS4_MAX_UINT64, PAGE_SIZE);
788 }
789
790 ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end);
791 }
792
793 static int
794 bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg)
795 {
796 return ext_tree_prepare_commit(arg);
797 }
798
799 static void
800 bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
801 {
802 ext_tree_mark_committed(&lcdata->args, lcdata->res.status);
803 }
804
805 static int
806 bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
807 {
808 dprintk("%s enter\n", __func__);
809
810 if (server->pnfs_blksize == 0) {
811 dprintk("%s Server did not return blksize\n", __func__);
812 return -EINVAL;
813 }
814 if (server->pnfs_blksize > PAGE_SIZE) {
815 printk(KERN_ERR "%s: pNFS blksize %d not supported.\n",
816 __func__, server->pnfs_blksize);
817 return -EINVAL;
818 }
819
820 return 0;
821 }
822
823 static bool
824 is_aligned_req(struct nfs_pageio_descriptor *pgio,
825 struct nfs_page *req, unsigned int alignment, bool is_write)
826 {
827 /*
828 * Always accept buffered writes, higher layers take care of the
829 * right alignment.
830 */
831 if (pgio->pg_dreq == NULL)
832 return true;
833
834 if (!IS_ALIGNED(req->wb_offset, alignment))
835 return false;
836
837 if (IS_ALIGNED(req->wb_bytes, alignment))
838 return true;
839
840 if (is_write &&
841 (req_offset(req) + req->wb_bytes == i_size_read(pgio->pg_inode))) {
842 /*
843 * If the write goes up to the inode size, just write
844 * the full page. Data past the inode size is
845 * guaranteed to be zeroed by the higher level client
846 * code, and this behaviour is mandated by RFC 5663
847 * section 2.3.2.
848 */
849 return true;
850 }
851
852 return false;
853 }
854
855 static void
856 bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
857 {
858 if (!is_aligned_req(pgio, req, SECTOR_SIZE, false)) {
859 nfs_pageio_reset_read_mds(pgio);
860 return;
861 }
862
863 pnfs_generic_pg_init_read(pgio, req);
864
865 if (pgio->pg_lseg &&
866 test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
867 pnfs_error_mark_layout_for_return(pgio->pg_inode, pgio->pg_lseg);
868 pnfs_set_lo_fail(pgio->pg_lseg);
869 nfs_pageio_reset_read_mds(pgio);
870 }
871 }
872
873 /*
874 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
875 * of bytes (maximum @req->wb_bytes) that can be coalesced.
876 */
877 static size_t
878 bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
879 struct nfs_page *req)
880 {
881 if (!is_aligned_req(pgio, req, SECTOR_SIZE, false))
882 return 0;
883 return pnfs_generic_pg_test(pgio, prev, req);
884 }
885
886 /*
887 * Return the number of contiguous bytes for a given inode
888 * starting at page frame idx.
889 */
890 static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
891 {
892 struct address_space *mapping = inode->i_mapping;
893 pgoff_t end;
894
895 /* Optimize common case that writes from 0 to end of file */
896 end = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
897 if (end != inode->i_mapping->nrpages) {
898 rcu_read_lock();
899 end = page_cache_next_miss(mapping, idx + 1, ULONG_MAX);
900 rcu_read_unlock();
901 }
902
903 if (!end)
904 return i_size_read(inode) - (idx << PAGE_SHIFT);
905 else
906 return (end - idx) << PAGE_SHIFT;
907 }
908
909 static void
910 bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
911 {
912 u64 wb_size;
913
914 if (!is_aligned_req(pgio, req, PAGE_SIZE, true)) {
915 nfs_pageio_reset_write_mds(pgio);
916 return;
917 }
918
919 if (pgio->pg_dreq == NULL)
920 wb_size = pnfs_num_cont_bytes(pgio->pg_inode,
921 req->wb_index);
922 else
923 wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
924
925 pnfs_generic_pg_init_write(pgio, req, wb_size);
926
927 if (pgio->pg_lseg &&
928 test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
929
930 pnfs_error_mark_layout_for_return(pgio->pg_inode, pgio->pg_lseg);
931 pnfs_set_lo_fail(pgio->pg_lseg);
932 nfs_pageio_reset_write_mds(pgio);
933 }
934 }
935
936 /*
937 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
938 * of bytes (maximum @req->wb_bytes) that can be coalesced.
939 */
940 static size_t
941 bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
942 struct nfs_page *req)
943 {
944 if (!is_aligned_req(pgio, req, PAGE_SIZE, true))
945 return 0;
946 return pnfs_generic_pg_test(pgio, prev, req);
947 }
948
949 static const struct nfs_pageio_ops bl_pg_read_ops = {
950 .pg_init = bl_pg_init_read,
951 .pg_test = bl_pg_test_read,
952 .pg_doio = pnfs_generic_pg_readpages,
953 .pg_cleanup = pnfs_generic_pg_cleanup,
954 };
955
956 static const struct nfs_pageio_ops bl_pg_write_ops = {
957 .pg_init = bl_pg_init_write,
958 .pg_test = bl_pg_test_write,
959 .pg_doio = pnfs_generic_pg_writepages,
960 .pg_cleanup = pnfs_generic_pg_cleanup,
961 };
962
963 static struct pnfs_layoutdriver_type blocklayout_type = {
964 .id = LAYOUT_BLOCK_VOLUME,
965 .name = "LAYOUT_BLOCK_VOLUME",
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 = bl_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 static struct pnfs_layoutdriver_type scsilayout_type = {
988 .id = LAYOUT_SCSI,
989 .name = "LAYOUT_SCSI",
990 .owner = THIS_MODULE,
991 .flags = PNFS_LAYOUTRET_ON_SETATTR |
992 PNFS_LAYOUTRET_ON_ERROR |
993 PNFS_READ_WHOLE_PAGE,
994 .read_pagelist = bl_read_pagelist,
995 .write_pagelist = bl_write_pagelist,
996 .alloc_layout_hdr = sl_alloc_layout_hdr,
997 .free_layout_hdr = bl_free_layout_hdr,
998 .alloc_lseg = bl_alloc_lseg,
999 .free_lseg = bl_free_lseg,
1000 .return_range = bl_return_range,
1001 .prepare_layoutcommit = bl_prepare_layoutcommit,
1002 .cleanup_layoutcommit = bl_cleanup_layoutcommit,
1003 .set_layoutdriver = bl_set_layoutdriver,
1004 .alloc_deviceid_node = bl_alloc_deviceid_node,
1005 .free_deviceid_node = bl_free_deviceid_node,
1006 .pg_read_ops = &bl_pg_read_ops,
1007 .pg_write_ops = &bl_pg_write_ops,
1008 .sync = pnfs_generic_sync,
1009 };
1010
1011
1012 static int __init nfs4blocklayout_init(void)
1013 {
1014 int ret;
1015
1016 dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__);
1017
1018 ret = bl_init_pipefs();
1019 if (ret)
1020 goto out;
1021
1022 ret = pnfs_register_layoutdriver(&blocklayout_type);
1023 if (ret)
1024 goto out_cleanup_pipe;
1025
1026 ret = pnfs_register_layoutdriver(&scsilayout_type);
1027 if (ret)
1028 goto out_unregister_block;
1029 return 0;
1030
1031 out_unregister_block:
1032 pnfs_unregister_layoutdriver(&blocklayout_type);
1033 out_cleanup_pipe:
1034 bl_cleanup_pipefs();
1035 out:
1036 return ret;
1037 }
1038
1039 static void __exit nfs4blocklayout_exit(void)
1040 {
1041 dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
1042 __func__);
1043
1044 pnfs_unregister_layoutdriver(&scsilayout_type);
1045 pnfs_unregister_layoutdriver(&blocklayout_type);
1046 bl_cleanup_pipefs();
1047 }
1048
1049 MODULE_ALIAS("nfs-layouttype4-3");
1050 MODULE_ALIAS("nfs-layouttype4-5");
1051
1052 module_init(nfs4blocklayout_init);
1053 module_exit(nfs4blocklayout_exit);
Linux with added FPC-III support