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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/lightnvm/pblk-read.c
2 * Copyright (C) 2016 CNEX Labs
3 * Initial release: Javier Gonzalez <javier@cnexlabs.com>
4 * Matias Bjorling <matias@cnexlabs.com>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * pblk-read.c - pblk's read path
21 * There is no guarantee that the value read from cache has not been updated and
22 * resides at another location in the cache. We guarantee though that if the
23 * value is read from the cache, it belongs to the mapped lba. In order to
24 * guarantee and order between writes and reads are ordered, a flush must be
27 static int pblk_read_from_cache(struct pblk
*pblk
, struct bio
*bio
,
28 sector_t lba
, struct ppa_addr ppa
,
31 #ifdef CONFIG_NVM_DEBUG
32 /* Callers must ensure that the ppa points to a cache address */
33 BUG_ON(pblk_ppa_empty(ppa
));
34 BUG_ON(!pblk_addr_in_cache(ppa
));
37 return pblk_rb_copy_to_bio(&pblk
->rwb
, bio
, lba
,
38 pblk_addr_to_cacheline(ppa
), bio_iter
);
41 static void pblk_read_ppalist_rq(struct pblk
*pblk
, struct nvm_rq
*rqd
,
42 unsigned long *read_bitmap
)
44 struct bio
*bio
= rqd
->bio
;
45 struct ppa_addr ppas
[PBLK_MAX_REQ_ADDRS
];
46 sector_t blba
= pblk_get_lba(bio
);
47 int nr_secs
= rqd
->nr_ppas
;
51 /* logic error: lba out-of-bounds. Ignore read request */
52 if (blba
+ nr_secs
>= pblk
->rl
.nr_secs
) {
53 WARN(1, "pblk: read lbas out of bounds\n");
57 pblk_lookup_l2p_seq(pblk
, ppas
, blba
, nr_secs
);
59 for (i
= 0; i
< nr_secs
; i
++) {
60 struct ppa_addr p
= ppas
[i
];
61 sector_t lba
= blba
+ i
;
64 if (pblk_ppa_empty(p
)) {
65 WARN_ON(test_and_set_bit(i
, read_bitmap
));
69 /* Try to read from write buffer. The address is later checked
70 * on the write buffer to prevent retrieving overwritten data.
72 if (pblk_addr_in_cache(p
)) {
73 if (!pblk_read_from_cache(pblk
, bio
, lba
, p
, i
)) {
74 pblk_lookup_l2p_seq(pblk
, &p
, lba
, 1);
77 WARN_ON(test_and_set_bit(i
, read_bitmap
));
80 /* Read from media non-cached sectors */
81 rqd
->ppa_list
[j
++] = p
;
85 bio_advance(bio
, PBLK_EXPOSED_PAGE_SIZE
);
88 #ifdef CONFIG_NVM_DEBUG
89 atomic_long_add(nr_secs
, &pblk
->inflight_reads
);
93 static int pblk_submit_read_io(struct pblk
*pblk
, struct nvm_rq
*rqd
)
97 rqd
->flags
= pblk_set_read_mode(pblk
);
99 err
= pblk_submit_io(pblk
, rqd
);
106 static void pblk_end_io_read(struct nvm_rq
*rqd
)
108 struct pblk
*pblk
= rqd
->private;
109 struct nvm_tgt_dev
*dev
= pblk
->dev
;
110 struct pblk_r_ctx
*r_ctx
= nvm_rq_to_pdu(rqd
);
111 struct bio
*bio
= rqd
->bio
;
114 pblk_log_read_err(pblk
, rqd
);
115 #ifdef CONFIG_NVM_DEBUG
117 WARN_ONCE(bio
->bi_error
, "pblk: corrupted read error\n");
120 if (rqd
->nr_ppas
> 1)
121 nvm_dev_dma_free(dev
->parent
, rqd
->ppa_list
, rqd
->dma_ppa_list
);
124 if (r_ctx
->orig_bio
) {
125 #ifdef CONFIG_NVM_DEBUG
126 WARN_ONCE(r_ctx
->orig_bio
->bi_error
,
127 "pblk: corrupted read bio\n");
129 bio_endio(r_ctx
->orig_bio
);
130 bio_put(r_ctx
->orig_bio
);
133 #ifdef CONFIG_NVM_DEBUG
134 atomic_long_add(rqd
->nr_ppas
, &pblk
->sync_reads
);
135 atomic_long_sub(rqd
->nr_ppas
, &pblk
->inflight_reads
);
138 pblk_free_rqd(pblk
, rqd
, READ
);
141 static int pblk_fill_partial_read_bio(struct pblk
*pblk
, struct nvm_rq
*rqd
,
142 unsigned int bio_init_idx
,
143 unsigned long *read_bitmap
)
145 struct bio
*new_bio
, *bio
= rqd
->bio
;
146 struct bio_vec src_bv
, dst_bv
;
147 void *ppa_ptr
= NULL
;
149 dma_addr_t dma_ppa_list
= 0;
150 int nr_secs
= rqd
->nr_ppas
;
151 int nr_holes
= nr_secs
- bitmap_weight(read_bitmap
, nr_secs
);
153 DECLARE_COMPLETION_ONSTACK(wait
);
155 new_bio
= bio_alloc(GFP_KERNEL
, nr_holes
);
157 pr_err("pblk: could not alloc read bio\n");
161 if (pblk_bio_add_pages(pblk
, new_bio
, GFP_KERNEL
, nr_holes
))
164 if (nr_holes
!= new_bio
->bi_vcnt
) {
165 pr_err("pblk: malformed bio\n");
169 new_bio
->bi_iter
.bi_sector
= 0; /* internal bio */
170 bio_set_op_attrs(new_bio
, REQ_OP_READ
, 0);
171 new_bio
->bi_private
= &wait
;
172 new_bio
->bi_end_io
= pblk_end_bio_sync
;
175 rqd
->nr_ppas
= nr_holes
;
178 if (unlikely(nr_secs
> 1 && nr_holes
== 1)) {
179 ppa_ptr
= rqd
->ppa_list
;
180 dma_ppa_list
= rqd
->dma_ppa_list
;
181 rqd
->ppa_addr
= rqd
->ppa_list
[0];
184 ret
= pblk_submit_read_io(pblk
, rqd
);
187 pr_err("pblk: read IO submission failed\n");
191 if (!wait_for_completion_io_timeout(&wait
,
192 msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS
))) {
193 pr_err("pblk: partial read I/O timed out\n");
197 atomic_long_inc(&pblk
->read_failed
);
198 #ifdef CONFIG_NVM_DEBUG
199 pblk_print_failed_rqd(pblk
, rqd
, rqd
->error
);
203 if (unlikely(nr_secs
> 1 && nr_holes
== 1)) {
204 rqd
->ppa_list
= ppa_ptr
;
205 rqd
->dma_ppa_list
= dma_ppa_list
;
208 /* Fill the holes in the original bio */
210 hole
= find_first_zero_bit(read_bitmap
, nr_secs
);
212 src_bv
= new_bio
->bi_io_vec
[i
++];
213 dst_bv
= bio
->bi_io_vec
[bio_init_idx
+ hole
];
215 src_p
= kmap_atomic(src_bv
.bv_page
);
216 dst_p
= kmap_atomic(dst_bv
.bv_page
);
218 memcpy(dst_p
+ dst_bv
.bv_offset
,
219 src_p
+ src_bv
.bv_offset
,
220 PBLK_EXPOSED_PAGE_SIZE
);
222 kunmap_atomic(src_p
);
223 kunmap_atomic(dst_p
);
225 mempool_free(src_bv
.bv_page
, pblk
->page_pool
);
227 hole
= find_next_zero_bit(read_bitmap
, nr_secs
, hole
+ 1);
228 } while (hole
< nr_secs
);
232 /* Complete the original bio and associated request */
234 rqd
->nr_ppas
= nr_secs
;
238 pblk_end_io_read(rqd
);
242 /* Free allocated pages in new bio */
243 pblk_bio_free_pages(pblk
, bio
, 0, new_bio
->bi_vcnt
);
245 pblk_end_io_read(rqd
);
249 static void pblk_read_rq(struct pblk
*pblk
, struct nvm_rq
*rqd
,
250 unsigned long *read_bitmap
)
252 struct bio
*bio
= rqd
->bio
;
254 sector_t lba
= pblk_get_lba(bio
);
256 /* logic error: lba out-of-bounds. Ignore read request */
257 if (lba
>= pblk
->rl
.nr_secs
) {
258 WARN(1, "pblk: read lba out of bounds\n");
262 pblk_lookup_l2p_seq(pblk
, &ppa
, lba
, 1);
264 #ifdef CONFIG_NVM_DEBUG
265 atomic_long_inc(&pblk
->inflight_reads
);
269 if (pblk_ppa_empty(ppa
)) {
270 WARN_ON(test_and_set_bit(0, read_bitmap
));
274 /* Try to read from write buffer. The address is later checked on the
275 * write buffer to prevent retrieving overwritten data.
277 if (pblk_addr_in_cache(ppa
)) {
278 if (!pblk_read_from_cache(pblk
, bio
, lba
, ppa
, 0)) {
279 pblk_lookup_l2p_seq(pblk
, &ppa
, lba
, 1);
282 WARN_ON(test_and_set_bit(0, read_bitmap
));
288 int pblk_submit_read(struct pblk
*pblk
, struct bio
*bio
)
290 struct nvm_tgt_dev
*dev
= pblk
->dev
;
291 unsigned int nr_secs
= pblk_get_secs(bio
);
293 unsigned long read_bitmap
; /* Max 64 ppas per request */
294 unsigned int bio_init_idx
;
295 int ret
= NVM_IO_ERR
;
297 if (nr_secs
> PBLK_MAX_REQ_ADDRS
)
300 bitmap_zero(&read_bitmap
, nr_secs
);
302 rqd
= pblk_alloc_rqd(pblk
, READ
);
304 pr_err_ratelimited("pblk: not able to alloc rqd");
308 rqd
->opcode
= NVM_OP_PREAD
;
310 rqd
->nr_ppas
= nr_secs
;
312 rqd
->end_io
= pblk_end_io_read
;
314 /* Save the index for this bio's start. This is needed in case
315 * we need to fill a partial read.
317 bio_init_idx
= pblk_get_bi_idx(bio
);
320 rqd
->ppa_list
= nvm_dev_dma_alloc(dev
->parent
, GFP_KERNEL
,
322 if (!rqd
->ppa_list
) {
323 pr_err("pblk: not able to allocate ppa list\n");
327 pblk_read_ppalist_rq(pblk
, rqd
, &read_bitmap
);
329 pblk_read_rq(pblk
, rqd
, &read_bitmap
);
333 if (bitmap_full(&read_bitmap
, nr_secs
)) {
335 pblk_end_io_read(rqd
);
339 /* All sectors are to be read from the device */
340 if (bitmap_empty(&read_bitmap
, rqd
->nr_ppas
)) {
341 struct bio
*int_bio
= NULL
;
342 struct pblk_r_ctx
*r_ctx
= nvm_rq_to_pdu(rqd
);
344 /* Clone read bio to deal with read errors internally */
345 int_bio
= bio_clone_bioset(bio
, GFP_KERNEL
, fs_bio_set
);
347 pr_err("pblk: could not clone read bio\n");
352 r_ctx
->orig_bio
= bio
;
354 ret
= pblk_submit_read_io(pblk
, rqd
);
356 pr_err("pblk: read IO submission failed\n");
365 /* The read bio request could be partially filled by the write buffer,
366 * but there are some holes that need to be read from the drive.
368 ret
= pblk_fill_partial_read_bio(pblk
, rqd
, bio_init_idx
, &read_bitmap
);
370 pr_err("pblk: failed to perform partial read\n");
377 pblk_free_rqd(pblk
, rqd
, READ
);
381 static int read_ppalist_rq_gc(struct pblk
*pblk
, struct nvm_rq
*rqd
,
382 struct pblk_line
*line
, u64
*lba_list
,
383 unsigned int nr_secs
)
385 struct ppa_addr ppas
[PBLK_MAX_REQ_ADDRS
];
389 pblk_lookup_l2p_rand(pblk
, ppas
, lba_list
, nr_secs
);
391 for (i
= 0; i
< nr_secs
; i
++) {
392 if (pblk_addr_in_cache(ppas
[i
]) || ppas
[i
].g
.blk
!= line
->id
||
393 pblk_ppa_empty(ppas
[i
])) {
394 lba_list
[i
] = ADDR_EMPTY
;
398 rqd
->ppa_list
[valid_secs
++] = ppas
[i
];
401 #ifdef CONFIG_NVM_DEBUG
402 atomic_long_add(valid_secs
, &pblk
->inflight_reads
);
407 static int read_rq_gc(struct pblk
*pblk
, struct nvm_rq
*rqd
,
408 struct pblk_line
*line
, sector_t lba
)
413 if (lba
== ADDR_EMPTY
)
416 /* logic error: lba out-of-bounds */
417 if (lba
>= pblk
->rl
.nr_secs
) {
418 WARN(1, "pblk: read lba out of bounds\n");
422 spin_lock(&pblk
->trans_lock
);
423 ppa
= pblk_trans_map_get(pblk
, lba
);
424 spin_unlock(&pblk
->trans_lock
);
426 /* Ignore updated values until the moment */
427 if (pblk_addr_in_cache(ppa
) || ppa
.g
.blk
!= line
->id
||
434 #ifdef CONFIG_NVM_DEBUG
435 atomic_long_inc(&pblk
->inflight_reads
);
442 int pblk_submit_read_gc(struct pblk
*pblk
, u64
*lba_list
, void *data
,
443 unsigned int nr_secs
, unsigned int *secs_to_gc
,
444 struct pblk_line
*line
)
446 struct nvm_tgt_dev
*dev
= pblk
->dev
;
447 struct nvm_geo
*geo
= &dev
->geo
;
448 struct request_queue
*q
= dev
->q
;
452 DECLARE_COMPLETION_ONSTACK(wait
);
454 memset(&rqd
, 0, sizeof(struct nvm_rq
));
457 rqd
.ppa_list
= nvm_dev_dma_alloc(dev
->parent
, GFP_KERNEL
,
462 *secs_to_gc
= read_ppalist_rq_gc(pblk
, &rqd
, line
, lba_list
,
464 if (*secs_to_gc
== 1) {
467 ppa
= rqd
.ppa_list
[0];
468 nvm_dev_dma_free(dev
->parent
, rqd
.ppa_list
,
473 *secs_to_gc
= read_rq_gc(pblk
, &rqd
, line
, lba_list
[0]);
479 data_len
= (*secs_to_gc
) * geo
->sec_size
;
480 bio
= bio_map_kern(q
, data
, data_len
, GFP_KERNEL
);
482 pr_err("pblk: could not allocate GC bio (%lu)\n", PTR_ERR(bio
));
486 bio
->bi_iter
.bi_sector
= 0; /* internal bio */
487 bio_set_op_attrs(bio
, REQ_OP_READ
, 0);
489 rqd
.opcode
= NVM_OP_PREAD
;
490 rqd
.end_io
= pblk_end_io_sync
;
492 rqd
.nr_ppas
= *secs_to_gc
;
495 ret
= pblk_submit_read_io(pblk
, &rqd
);
498 pr_err("pblk: GC read request failed\n");
502 if (!wait_for_completion_io_timeout(&wait
,
503 msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS
))) {
504 pr_err("pblk: GC read I/O timed out\n");
508 atomic_long_inc(&pblk
->read_failed_gc
);
509 #ifdef CONFIG_NVM_DEBUG
510 pblk_print_failed_rqd(pblk
, &rqd
, rqd
.error
);
514 #ifdef CONFIG_NVM_DEBUG
515 atomic_long_add(*secs_to_gc
, &pblk
->sync_reads
);
516 atomic_long_add(*secs_to_gc
, &pblk
->recov_gc_reads
);
517 atomic_long_sub(*secs_to_gc
, &pblk
->inflight_reads
);
522 nvm_dev_dma_free(dev
->parent
, rqd
.ppa_list
, rqd
.dma_ppa_list
);
527 nvm_dev_dma_free(dev
->parent
, rqd
.ppa_list
, rqd
.dma_ppa_list
);