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git.proxmox.com Git - mirror_ubuntu-bionic-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
, ppa
, bio_iter
);
40 static void pblk_read_ppalist_rq(struct pblk
*pblk
, struct nvm_rq
*rqd
,
41 unsigned long *read_bitmap
)
43 struct bio
*bio
= rqd
->bio
;
44 struct ppa_addr ppas
[PBLK_MAX_REQ_ADDRS
];
45 sector_t blba
= pblk_get_lba(bio
);
46 int nr_secs
= rqd
->nr_ppas
;
50 /* logic error: lba out-of-bounds. Ignore read request */
51 if (blba
+ nr_secs
>= pblk
->rl
.nr_secs
) {
52 WARN(1, "pblk: read lbas out of bounds\n");
56 pblk_lookup_l2p_seq(pblk
, ppas
, blba
, nr_secs
);
58 for (i
= 0; i
< nr_secs
; i
++) {
59 struct ppa_addr p
= ppas
[i
];
60 sector_t lba
= blba
+ i
;
63 if (pblk_ppa_empty(p
)) {
64 WARN_ON(test_and_set_bit(i
, read_bitmap
));
68 /* Try to read from write buffer. The address is later checked
69 * on the write buffer to prevent retrieving overwritten data.
71 if (pblk_addr_in_cache(p
)) {
72 if (!pblk_read_from_cache(pblk
, bio
, lba
, p
, i
)) {
73 pblk_lookup_l2p_seq(pblk
, &p
, lba
, 1);
76 WARN_ON(test_and_set_bit(i
, read_bitmap
));
78 #ifdef CONFIG_NVM_DEBUG
79 atomic_long_inc(&pblk
->cache_reads
);
82 /* Read from media non-cached sectors */
83 rqd
->ppa_list
[j
++] = p
;
87 bio_advance(bio
, PBLK_EXPOSED_PAGE_SIZE
);
90 if (pblk_io_aligned(pblk
, nr_secs
))
91 rqd
->flags
= pblk_set_read_mode(pblk
, PBLK_READ_SEQUENTIAL
);
93 rqd
->flags
= pblk_set_read_mode(pblk
, PBLK_READ_RANDOM
);
95 #ifdef CONFIG_NVM_DEBUG
96 atomic_long_add(nr_secs
, &pblk
->inflight_reads
);
100 static int pblk_submit_read_io(struct pblk
*pblk
, struct nvm_rq
*rqd
)
104 err
= pblk_submit_io(pblk
, rqd
);
111 static void pblk_end_io_read(struct nvm_rq
*rqd
)
113 struct pblk
*pblk
= rqd
->private;
114 struct nvm_tgt_dev
*dev
= pblk
->dev
;
115 struct pblk_g_ctx
*r_ctx
= nvm_rq_to_pdu(rqd
);
116 struct bio
*bio
= rqd
->bio
;
119 pblk_log_read_err(pblk
, rqd
);
120 #ifdef CONFIG_NVM_DEBUG
122 WARN_ONCE(bio
->bi_status
, "pblk: corrupted read error\n");
125 nvm_dev_dma_free(dev
->parent
, rqd
->meta_list
, rqd
->dma_meta_list
);
128 if (r_ctx
->private) {
129 struct bio
*orig_bio
= r_ctx
->private;
131 #ifdef CONFIG_NVM_DEBUG
132 WARN_ONCE(orig_bio
->bi_status
, "pblk: corrupted read bio\n");
138 #ifdef CONFIG_NVM_DEBUG
139 atomic_long_add(rqd
->nr_ppas
, &pblk
->sync_reads
);
140 atomic_long_sub(rqd
->nr_ppas
, &pblk
->inflight_reads
);
143 pblk_free_rqd(pblk
, rqd
, READ
);
144 atomic_dec(&pblk
->inflight_io
);
147 static int pblk_fill_partial_read_bio(struct pblk
*pblk
, struct nvm_rq
*rqd
,
148 unsigned int bio_init_idx
,
149 unsigned long *read_bitmap
)
151 struct bio
*new_bio
, *bio
= rqd
->bio
;
152 struct bio_vec src_bv
, dst_bv
;
153 void *ppa_ptr
= NULL
;
155 dma_addr_t dma_ppa_list
= 0;
156 int nr_secs
= rqd
->nr_ppas
;
157 int nr_holes
= nr_secs
- bitmap_weight(read_bitmap
, nr_secs
);
159 DECLARE_COMPLETION_ONSTACK(wait
);
161 new_bio
= bio_alloc(GFP_KERNEL
, nr_holes
);
163 pr_err("pblk: could not alloc read bio\n");
167 if (pblk_bio_add_pages(pblk
, new_bio
, GFP_KERNEL
, nr_holes
))
170 if (nr_holes
!= new_bio
->bi_vcnt
) {
171 pr_err("pblk: malformed bio\n");
175 new_bio
->bi_iter
.bi_sector
= 0; /* internal bio */
176 bio_set_op_attrs(new_bio
, REQ_OP_READ
, 0);
177 new_bio
->bi_private
= &wait
;
178 new_bio
->bi_end_io
= pblk_end_bio_sync
;
181 rqd
->nr_ppas
= nr_holes
;
182 rqd
->flags
= pblk_set_read_mode(pblk
, PBLK_READ_RANDOM
);
185 if (unlikely(nr_secs
> 1 && nr_holes
== 1)) {
186 ppa_ptr
= rqd
->ppa_list
;
187 dma_ppa_list
= rqd
->dma_ppa_list
;
188 rqd
->ppa_addr
= rqd
->ppa_list
[0];
191 ret
= pblk_submit_read_io(pblk
, rqd
);
194 pr_err("pblk: read IO submission failed\n");
198 if (!wait_for_completion_io_timeout(&wait
,
199 msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS
))) {
200 pr_err("pblk: partial read I/O timed out\n");
204 atomic_long_inc(&pblk
->read_failed
);
205 #ifdef CONFIG_NVM_DEBUG
206 pblk_print_failed_rqd(pblk
, rqd
, rqd
->error
);
210 if (unlikely(nr_secs
> 1 && nr_holes
== 1)) {
211 rqd
->ppa_list
= ppa_ptr
;
212 rqd
->dma_ppa_list
= dma_ppa_list
;
215 /* Fill the holes in the original bio */
217 hole
= find_first_zero_bit(read_bitmap
, nr_secs
);
219 src_bv
= new_bio
->bi_io_vec
[i
++];
220 dst_bv
= bio
->bi_io_vec
[bio_init_idx
+ hole
];
222 src_p
= kmap_atomic(src_bv
.bv_page
);
223 dst_p
= kmap_atomic(dst_bv
.bv_page
);
225 memcpy(dst_p
+ dst_bv
.bv_offset
,
226 src_p
+ src_bv
.bv_offset
,
227 PBLK_EXPOSED_PAGE_SIZE
);
229 kunmap_atomic(src_p
);
230 kunmap_atomic(dst_p
);
232 mempool_free(src_bv
.bv_page
, pblk
->page_pool
);
234 hole
= find_next_zero_bit(read_bitmap
, nr_secs
, hole
+ 1);
235 } while (hole
< nr_secs
);
239 /* Complete the original bio and associated request */
241 rqd
->nr_ppas
= nr_secs
;
245 pblk_end_io_read(rqd
);
249 /* Free allocated pages in new bio */
250 pblk_bio_free_pages(pblk
, bio
, 0, new_bio
->bi_vcnt
);
252 pblk_end_io_read(rqd
);
256 static void pblk_read_rq(struct pblk
*pblk
, struct nvm_rq
*rqd
,
257 unsigned long *read_bitmap
)
259 struct bio
*bio
= rqd
->bio
;
261 sector_t lba
= pblk_get_lba(bio
);
263 /* logic error: lba out-of-bounds. Ignore read request */
264 if (lba
>= pblk
->rl
.nr_secs
) {
265 WARN(1, "pblk: read lba out of bounds\n");
269 pblk_lookup_l2p_seq(pblk
, &ppa
, lba
, 1);
271 #ifdef CONFIG_NVM_DEBUG
272 atomic_long_inc(&pblk
->inflight_reads
);
276 if (pblk_ppa_empty(ppa
)) {
277 WARN_ON(test_and_set_bit(0, read_bitmap
));
281 /* Try to read from write buffer. The address is later checked on the
282 * write buffer to prevent retrieving overwritten data.
284 if (pblk_addr_in_cache(ppa
)) {
285 if (!pblk_read_from_cache(pblk
, bio
, lba
, ppa
, 0)) {
286 pblk_lookup_l2p_seq(pblk
, &ppa
, lba
, 1);
289 WARN_ON(test_and_set_bit(0, read_bitmap
));
290 #ifdef CONFIG_NVM_DEBUG
291 atomic_long_inc(&pblk
->cache_reads
);
297 rqd
->flags
= pblk_set_read_mode(pblk
, PBLK_READ_RANDOM
);
300 int pblk_submit_read(struct pblk
*pblk
, struct bio
*bio
)
302 struct nvm_tgt_dev
*dev
= pblk
->dev
;
303 unsigned int nr_secs
= pblk_get_secs(bio
);
305 unsigned long read_bitmap
; /* Max 64 ppas per request */
306 unsigned int bio_init_idx
;
307 int ret
= NVM_IO_ERR
;
309 if (nr_secs
> PBLK_MAX_REQ_ADDRS
)
312 bitmap_zero(&read_bitmap
, nr_secs
);
314 rqd
= pblk_alloc_rqd(pblk
, READ
);
316 pr_err_ratelimited("pblk: not able to alloc rqd");
320 rqd
->opcode
= NVM_OP_PREAD
;
322 rqd
->nr_ppas
= nr_secs
;
324 rqd
->end_io
= pblk_end_io_read
;
326 /* Save the index for this bio's start. This is needed in case
327 * we need to fill a partial read.
329 bio_init_idx
= pblk_get_bi_idx(bio
);
331 rqd
->meta_list
= nvm_dev_dma_alloc(dev
->parent
, GFP_KERNEL
,
332 &rqd
->dma_meta_list
);
333 if (!rqd
->meta_list
) {
334 pr_err("pblk: not able to allocate ppa list\n");
339 rqd
->ppa_list
= rqd
->meta_list
+ pblk_dma_meta_size
;
340 rqd
->dma_ppa_list
= rqd
->dma_meta_list
+ pblk_dma_meta_size
;
342 pblk_read_ppalist_rq(pblk
, rqd
, &read_bitmap
);
344 pblk_read_rq(pblk
, rqd
, &read_bitmap
);
348 if (bitmap_full(&read_bitmap
, nr_secs
)) {
350 atomic_inc(&pblk
->inflight_io
);
351 pblk_end_io_read(rqd
);
355 /* All sectors are to be read from the device */
356 if (bitmap_empty(&read_bitmap
, rqd
->nr_ppas
)) {
357 struct bio
*int_bio
= NULL
;
358 struct pblk_g_ctx
*r_ctx
= nvm_rq_to_pdu(rqd
);
360 /* Clone read bio to deal with read errors internally */
361 int_bio
= bio_clone_fast(bio
, GFP_KERNEL
, pblk_bio_set
);
363 pr_err("pblk: could not clone read bio\n");
368 r_ctx
->private = bio
;
370 ret
= pblk_submit_read_io(pblk
, rqd
);
372 pr_err("pblk: read IO submission failed\n");
381 /* The read bio request could be partially filled by the write buffer,
382 * but there are some holes that need to be read from the drive.
384 ret
= pblk_fill_partial_read_bio(pblk
, rqd
, bio_init_idx
, &read_bitmap
);
386 pr_err("pblk: failed to perform partial read\n");
393 pblk_free_rqd(pblk
, rqd
, READ
);
397 static int read_ppalist_rq_gc(struct pblk
*pblk
, struct nvm_rq
*rqd
,
398 struct pblk_line
*line
, u64
*lba_list
,
399 unsigned int nr_secs
)
401 struct ppa_addr ppas
[PBLK_MAX_REQ_ADDRS
];
405 pblk_lookup_l2p_rand(pblk
, ppas
, lba_list
, nr_secs
);
407 for (i
= 0; i
< nr_secs
; i
++) {
408 if (pblk_addr_in_cache(ppas
[i
]) || ppas
[i
].g
.blk
!= line
->id
||
409 pblk_ppa_empty(ppas
[i
])) {
410 lba_list
[i
] = ADDR_EMPTY
;
414 rqd
->ppa_list
[valid_secs
++] = ppas
[i
];
417 #ifdef CONFIG_NVM_DEBUG
418 atomic_long_add(valid_secs
, &pblk
->inflight_reads
);
423 static int read_rq_gc(struct pblk
*pblk
, struct nvm_rq
*rqd
,
424 struct pblk_line
*line
, sector_t lba
)
429 if (lba
== ADDR_EMPTY
)
432 /* logic error: lba out-of-bounds */
433 if (lba
>= pblk
->rl
.nr_secs
) {
434 WARN(1, "pblk: read lba out of bounds\n");
438 spin_lock(&pblk
->trans_lock
);
439 ppa
= pblk_trans_map_get(pblk
, lba
);
440 spin_unlock(&pblk
->trans_lock
);
442 /* Ignore updated values until the moment */
443 if (pblk_addr_in_cache(ppa
) || ppa
.g
.blk
!= line
->id
||
450 #ifdef CONFIG_NVM_DEBUG
451 atomic_long_inc(&pblk
->inflight_reads
);
458 int pblk_submit_read_gc(struct pblk
*pblk
, u64
*lba_list
, void *data
,
459 unsigned int nr_secs
, unsigned int *secs_to_gc
,
460 struct pblk_line
*line
)
462 struct nvm_tgt_dev
*dev
= pblk
->dev
;
463 struct nvm_geo
*geo
= &dev
->geo
;
467 DECLARE_COMPLETION_ONSTACK(wait
);
469 memset(&rqd
, 0, sizeof(struct nvm_rq
));
471 rqd
.meta_list
= nvm_dev_dma_alloc(dev
->parent
, GFP_KERNEL
,
477 rqd
.ppa_list
= rqd
.meta_list
+ pblk_dma_meta_size
;
478 rqd
.dma_ppa_list
= rqd
.dma_meta_list
+ pblk_dma_meta_size
;
480 *secs_to_gc
= read_ppalist_rq_gc(pblk
, &rqd
, line
, lba_list
,
482 if (*secs_to_gc
== 1)
483 rqd
.ppa_addr
= rqd
.ppa_list
[0];
485 *secs_to_gc
= read_rq_gc(pblk
, &rqd
, line
, lba_list
[0]);
491 data_len
= (*secs_to_gc
) * geo
->sec_size
;
492 bio
= pblk_bio_map_addr(pblk
, data
, *secs_to_gc
, data_len
,
493 PBLK_KMALLOC_META
, GFP_KERNEL
);
495 pr_err("pblk: could not allocate GC bio (%lu)\n", PTR_ERR(bio
));
499 bio
->bi_iter
.bi_sector
= 0; /* internal bio */
500 bio_set_op_attrs(bio
, REQ_OP_READ
, 0);
502 rqd
.opcode
= NVM_OP_PREAD
;
503 rqd
.end_io
= pblk_end_io_sync
;
505 rqd
.nr_ppas
= *secs_to_gc
;
506 rqd
.flags
= pblk_set_read_mode(pblk
, PBLK_READ_RANDOM
);
509 ret
= pblk_submit_read_io(pblk
, &rqd
);
512 pr_err("pblk: GC read request failed\n");
516 if (!wait_for_completion_io_timeout(&wait
,
517 msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS
))) {
518 pr_err("pblk: GC read I/O timed out\n");
520 atomic_dec(&pblk
->inflight_io
);
523 atomic_long_inc(&pblk
->read_failed_gc
);
524 #ifdef CONFIG_NVM_DEBUG
525 pblk_print_failed_rqd(pblk
, &rqd
, rqd
.error
);
529 #ifdef CONFIG_NVM_DEBUG
530 atomic_long_add(*secs_to_gc
, &pblk
->sync_reads
);
531 atomic_long_add(*secs_to_gc
, &pblk
->recov_gc_reads
);
532 atomic_long_sub(*secs_to_gc
, &pblk
->inflight_reads
);
536 nvm_dev_dma_free(dev
->parent
, rqd
.meta_list
, rqd
.dma_meta_list
);
540 nvm_dev_dma_free(dev
->parent
, rqd
.meta_list
, rqd
.dma_meta_list
);