| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2016 CNEX Labs |
| * Initial release: Javier Gonzalez <javier@cnexlabs.com> |
| * Matias Bjorling <matias@cnexlabs.com> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License version |
| * 2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * pblk-read.c - pblk's read path |
| */ |
| |
| #include "pblk.h" |
| |
| /* |
| * There is no guarantee that the value read from cache has not been updated and |
| * resides at another location in the cache. We guarantee though that if the |
| * value is read from the cache, it belongs to the mapped lba. In order to |
| * guarantee and order between writes and reads are ordered, a flush must be |
| * issued. |
| */ |
| static int pblk_read_from_cache(struct pblk *pblk, struct bio *bio, |
| sector_t lba, struct ppa_addr ppa) |
| { |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| /* Callers must ensure that the ppa points to a cache address */ |
| BUG_ON(pblk_ppa_empty(ppa)); |
| BUG_ON(!pblk_addr_in_cache(ppa)); |
| #endif |
| |
| return pblk_rb_copy_to_bio(&pblk->rwb, bio, lba, ppa); |
| } |
| |
| static int pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd, |
| struct bio *bio, sector_t blba, |
| bool *from_cache) |
| { |
| void *meta_list = rqd->meta_list; |
| int nr_secs, i; |
| |
| retry: |
| nr_secs = pblk_lookup_l2p_seq(pblk, rqd->ppa_list, blba, rqd->nr_ppas, |
| from_cache); |
| |
| if (!*from_cache) |
| goto end; |
| |
| for (i = 0; i < nr_secs; i++) { |
| struct pblk_sec_meta *meta = pblk_get_meta(pblk, meta_list, i); |
| sector_t lba = blba + i; |
| |
| if (pblk_ppa_empty(rqd->ppa_list[i])) { |
| __le64 addr_empty = cpu_to_le64(ADDR_EMPTY); |
| |
| meta->lba = addr_empty; |
| } else if (pblk_addr_in_cache(rqd->ppa_list[i])) { |
| /* |
| * Try to read from write buffer. The address is later |
| * checked on the write buffer to prevent retrieving |
| * overwritten data. |
| */ |
| if (!pblk_read_from_cache(pblk, bio, lba, |
| rqd->ppa_list[i])) { |
| if (i == 0) { |
| /* |
| * We didn't call with bio_advance() |
| * yet, so we can just retry. |
| */ |
| goto retry; |
| } else { |
| /* |
| * We already call bio_advance() |
| * so we cannot retry and we need |
| * to quit that function in order |
| * to allow caller to handle the bio |
| * splitting in the current sector |
| * position. |
| */ |
| nr_secs = i; |
| goto end; |
| } |
| } |
| meta->lba = cpu_to_le64(lba); |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| atomic_long_inc(&pblk->cache_reads); |
| #endif |
| } |
| bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE); |
| } |
| |
| end: |
| if (pblk_io_aligned(pblk, nr_secs)) |
| rqd->is_seq = 1; |
| |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| atomic_long_add(nr_secs, &pblk->inflight_reads); |
| #endif |
| |
| return nr_secs; |
| } |
| |
| |
| static void pblk_read_check_seq(struct pblk *pblk, struct nvm_rq *rqd, |
| sector_t blba) |
| { |
| void *meta_list = rqd->meta_list; |
| int nr_lbas = rqd->nr_ppas; |
| int i; |
| |
| if (!pblk_is_oob_meta_supported(pblk)) |
| return; |
| |
| for (i = 0; i < nr_lbas; i++) { |
| struct pblk_sec_meta *meta = pblk_get_meta(pblk, meta_list, i); |
| u64 lba = le64_to_cpu(meta->lba); |
| |
| if (lba == ADDR_EMPTY) |
| continue; |
| |
| if (lba != blba + i) { |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| struct ppa_addr *ppa_list = nvm_rq_to_ppa_list(rqd); |
| |
| print_ppa(pblk, &ppa_list[i], "seq", i); |
| #endif |
| pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n", |
| lba, (u64)blba + i); |
| WARN_ON(1); |
| } |
| } |
| } |
| |
| /* |
| * There can be holes in the lba list. |
| */ |
| static void pblk_read_check_rand(struct pblk *pblk, struct nvm_rq *rqd, |
| u64 *lba_list, int nr_lbas) |
| { |
| void *meta_lba_list = rqd->meta_list; |
| int i, j; |
| |
| if (!pblk_is_oob_meta_supported(pblk)) |
| return; |
| |
| for (i = 0, j = 0; i < nr_lbas; i++) { |
| struct pblk_sec_meta *meta = pblk_get_meta(pblk, |
| meta_lba_list, j); |
| u64 lba = lba_list[i]; |
| u64 meta_lba; |
| |
| if (lba == ADDR_EMPTY) |
| continue; |
| |
| meta_lba = le64_to_cpu(meta->lba); |
| |
| if (lba != meta_lba) { |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| struct ppa_addr *ppa_list = nvm_rq_to_ppa_list(rqd); |
| |
| print_ppa(pblk, &ppa_list[j], "rnd", j); |
| #endif |
| pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n", |
| meta_lba, lba); |
| WARN_ON(1); |
| } |
| |
| j++; |
| } |
| |
| WARN_ONCE(j != rqd->nr_ppas, "pblk: corrupted random request\n"); |
| } |
| |
| static void pblk_end_user_read(struct bio *bio, int error) |
| { |
| if (error && error != NVM_RSP_WARN_HIGHECC) |
| bio_io_error(bio); |
| else |
| bio_endio(bio); |
| } |
| |
| static void __pblk_end_io_read(struct pblk *pblk, struct nvm_rq *rqd, |
| bool put_line) |
| { |
| struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd); |
| struct bio *int_bio = rqd->bio; |
| unsigned long start_time = r_ctx->start_time; |
| |
| bio_end_io_acct(int_bio, start_time); |
| |
| if (rqd->error) |
| pblk_log_read_err(pblk, rqd); |
| |
| pblk_read_check_seq(pblk, rqd, r_ctx->lba); |
| bio_put(int_bio); |
| |
| if (put_line) |
| pblk_rq_to_line_put(pblk, rqd); |
| |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| atomic_long_add(rqd->nr_ppas, &pblk->sync_reads); |
| atomic_long_sub(rqd->nr_ppas, &pblk->inflight_reads); |
| #endif |
| |
| pblk_free_rqd(pblk, rqd, PBLK_READ); |
| atomic_dec(&pblk->inflight_io); |
| } |
| |
| static void pblk_end_io_read(struct nvm_rq *rqd) |
| { |
| struct pblk *pblk = rqd->private; |
| struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd); |
| struct bio *bio = (struct bio *)r_ctx->private; |
| |
| pblk_end_user_read(bio, rqd->error); |
| __pblk_end_io_read(pblk, rqd, true); |
| } |
| |
| static void pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd, struct bio *bio, |
| sector_t lba, bool *from_cache) |
| { |
| struct pblk_sec_meta *meta = pblk_get_meta(pblk, rqd->meta_list, 0); |
| struct ppa_addr ppa; |
| |
| pblk_lookup_l2p_seq(pblk, &ppa, lba, 1, from_cache); |
| |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| atomic_long_inc(&pblk->inflight_reads); |
| #endif |
| |
| retry: |
| if (pblk_ppa_empty(ppa)) { |
| __le64 addr_empty = cpu_to_le64(ADDR_EMPTY); |
| |
| meta->lba = addr_empty; |
| return; |
| } |
| |
| /* Try to read from write buffer. The address is later checked on the |
| * write buffer to prevent retrieving overwritten data. |
| */ |
| if (pblk_addr_in_cache(ppa)) { |
| if (!pblk_read_from_cache(pblk, bio, lba, ppa)) { |
| pblk_lookup_l2p_seq(pblk, &ppa, lba, 1, from_cache); |
| goto retry; |
| } |
| |
| meta->lba = cpu_to_le64(lba); |
| |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| atomic_long_inc(&pblk->cache_reads); |
| #endif |
| } else { |
| rqd->ppa_addr = ppa; |
| } |
| } |
| |
| void pblk_submit_read(struct pblk *pblk, struct bio *bio) |
| { |
| sector_t blba = pblk_get_lba(bio); |
| unsigned int nr_secs = pblk_get_secs(bio); |
| bool from_cache; |
| struct pblk_g_ctx *r_ctx; |
| struct nvm_rq *rqd; |
| struct bio *int_bio, *split_bio; |
| unsigned long start_time; |
| |
| start_time = bio_start_io_acct(bio); |
| |
| rqd = pblk_alloc_rqd(pblk, PBLK_READ); |
| |
| rqd->opcode = NVM_OP_PREAD; |
| rqd->nr_ppas = nr_secs; |
| rqd->private = pblk; |
| rqd->end_io = pblk_end_io_read; |
| |
| r_ctx = nvm_rq_to_pdu(rqd); |
| r_ctx->start_time = start_time; |
| r_ctx->lba = blba; |
| |
| if (pblk_alloc_rqd_meta(pblk, rqd)) { |
| bio_io_error(bio); |
| pblk_free_rqd(pblk, rqd, PBLK_READ); |
| return; |
| } |
| |
| /* Clone read bio to deal internally with: |
| * -read errors when reading from drive |
| * -bio_advance() calls during cache reads |
| */ |
| int_bio = bio_clone_fast(bio, GFP_KERNEL, &pblk_bio_set); |
| |
| if (nr_secs > 1) |
| nr_secs = pblk_read_ppalist_rq(pblk, rqd, int_bio, blba, |
| &from_cache); |
| else |
| pblk_read_rq(pblk, rqd, int_bio, blba, &from_cache); |
| |
| split_retry: |
| r_ctx->private = bio; /* original bio */ |
| rqd->bio = int_bio; /* internal bio */ |
| |
| if (from_cache && nr_secs == rqd->nr_ppas) { |
| /* All data was read from cache, we can complete the IO. */ |
| pblk_end_user_read(bio, 0); |
| atomic_inc(&pblk->inflight_io); |
| __pblk_end_io_read(pblk, rqd, false); |
| } else if (nr_secs != rqd->nr_ppas) { |
| /* The read bio request could be partially filled by the write |
| * buffer, but there are some holes that need to be read from |
| * the drive. In order to handle this, we will use block layer |
| * mechanism to split this request in to smaller ones and make |
| * a chain of it. |
| */ |
| split_bio = bio_split(bio, nr_secs * NR_PHY_IN_LOG, GFP_KERNEL, |
| &pblk_bio_set); |
| bio_chain(split_bio, bio); |
| generic_make_request(bio); |
| |
| /* New bio contains first N sectors of the previous one, so |
| * we can continue to use existing rqd, but we need to shrink |
| * the number of PPAs in it. New bio is also guaranteed that |
| * it contains only either data from cache or from drive, newer |
| * mix of them. |
| */ |
| bio = split_bio; |
| rqd->nr_ppas = nr_secs; |
| if (rqd->nr_ppas == 1) |
| rqd->ppa_addr = rqd->ppa_list[0]; |
| |
| /* Recreate int_bio - existing might have some needed internal |
| * fields modified already. |
| */ |
| bio_put(int_bio); |
| int_bio = bio_clone_fast(bio, GFP_KERNEL, &pblk_bio_set); |
| goto split_retry; |
| } else if (pblk_submit_io(pblk, rqd, NULL)) { |
| /* Submitting IO to drive failed, let's report an error */ |
| rqd->error = -ENODEV; |
| pblk_end_io_read(rqd); |
| } |
| } |
| |
| static int read_ppalist_rq_gc(struct pblk *pblk, struct nvm_rq *rqd, |
| struct pblk_line *line, u64 *lba_list, |
| u64 *paddr_list_gc, unsigned int nr_secs) |
| { |
| struct ppa_addr ppa_list_l2p[NVM_MAX_VLBA]; |
| struct ppa_addr ppa_gc; |
| int valid_secs = 0; |
| int i; |
| |
| pblk_lookup_l2p_rand(pblk, ppa_list_l2p, lba_list, nr_secs); |
| |
| for (i = 0; i < nr_secs; i++) { |
| if (lba_list[i] == ADDR_EMPTY) |
| continue; |
| |
| ppa_gc = addr_to_gen_ppa(pblk, paddr_list_gc[i], line->id); |
| if (!pblk_ppa_comp(ppa_list_l2p[i], ppa_gc)) { |
| paddr_list_gc[i] = lba_list[i] = ADDR_EMPTY; |
| continue; |
| } |
| |
| rqd->ppa_list[valid_secs++] = ppa_list_l2p[i]; |
| } |
| |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| atomic_long_add(valid_secs, &pblk->inflight_reads); |
| #endif |
| |
| return valid_secs; |
| } |
| |
| static int read_rq_gc(struct pblk *pblk, struct nvm_rq *rqd, |
| struct pblk_line *line, sector_t lba, |
| u64 paddr_gc) |
| { |
| struct ppa_addr ppa_l2p, ppa_gc; |
| int valid_secs = 0; |
| |
| if (lba == ADDR_EMPTY) |
| goto out; |
| |
| /* logic error: lba out-of-bounds */ |
| if (lba >= pblk->capacity) { |
| WARN(1, "pblk: read lba out of bounds\n"); |
| goto out; |
| } |
| |
| spin_lock(&pblk->trans_lock); |
| ppa_l2p = pblk_trans_map_get(pblk, lba); |
| spin_unlock(&pblk->trans_lock); |
| |
| ppa_gc = addr_to_gen_ppa(pblk, paddr_gc, line->id); |
| if (!pblk_ppa_comp(ppa_l2p, ppa_gc)) |
| goto out; |
| |
| rqd->ppa_addr = ppa_l2p; |
| valid_secs = 1; |
| |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| atomic_long_inc(&pblk->inflight_reads); |
| #endif |
| |
| out: |
| return valid_secs; |
| } |
| |
| int pblk_submit_read_gc(struct pblk *pblk, struct pblk_gc_rq *gc_rq) |
| { |
| struct nvm_rq rqd; |
| int ret = NVM_IO_OK; |
| |
| memset(&rqd, 0, sizeof(struct nvm_rq)); |
| |
| ret = pblk_alloc_rqd_meta(pblk, &rqd); |
| if (ret) |
| return ret; |
| |
| if (gc_rq->nr_secs > 1) { |
| gc_rq->secs_to_gc = read_ppalist_rq_gc(pblk, &rqd, gc_rq->line, |
| gc_rq->lba_list, |
| gc_rq->paddr_list, |
| gc_rq->nr_secs); |
| if (gc_rq->secs_to_gc == 1) |
| rqd.ppa_addr = rqd.ppa_list[0]; |
| } else { |
| gc_rq->secs_to_gc = read_rq_gc(pblk, &rqd, gc_rq->line, |
| gc_rq->lba_list[0], |
| gc_rq->paddr_list[0]); |
| } |
| |
| if (!(gc_rq->secs_to_gc)) |
| goto out; |
| |
| rqd.opcode = NVM_OP_PREAD; |
| rqd.nr_ppas = gc_rq->secs_to_gc; |
| |
| if (pblk_submit_io_sync(pblk, &rqd, gc_rq->data)) { |
| ret = -EIO; |
| goto err_free_dma; |
| } |
| |
| pblk_read_check_rand(pblk, &rqd, gc_rq->lba_list, gc_rq->nr_secs); |
| |
| atomic_dec(&pblk->inflight_io); |
| |
| if (rqd.error) { |
| atomic_long_inc(&pblk->read_failed_gc); |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| pblk_print_failed_rqd(pblk, &rqd, rqd.error); |
| #endif |
| } |
| |
| #ifdef CONFIG_NVM_PBLK_DEBUG |
| atomic_long_add(gc_rq->secs_to_gc, &pblk->sync_reads); |
| atomic_long_add(gc_rq->secs_to_gc, &pblk->recov_gc_reads); |
| atomic_long_sub(gc_rq->secs_to_gc, &pblk->inflight_reads); |
| #endif |
| |
| out: |
| pblk_free_rqd_meta(pblk, &rqd); |
| return ret; |
| |
| err_free_dma: |
| pblk_free_rqd_meta(pblk, &rqd); |
| return ret; |
| } |