530 lines
13 KiB
C
530 lines
13 KiB
C
/*
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* Copyright (C) 2016 CNEX Labs
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* Initial release: Javier Gonzalez <javier@cnexlabs.com>
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* Matias Bjorling <matias@cnexlabs.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* pblk-read.c - pblk's read path
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*/
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#include "pblk.h"
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/*
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* There is no guarantee that the value read from cache has not been updated and
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* resides at another location in the cache. We guarantee though that if the
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* value is read from the cache, it belongs to the mapped lba. In order to
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* guarantee and order between writes and reads are ordered, a flush must be
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* issued.
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*/
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static int pblk_read_from_cache(struct pblk *pblk, struct bio *bio,
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sector_t lba, struct ppa_addr ppa,
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int bio_iter)
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{
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#ifdef CONFIG_NVM_DEBUG
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/* Callers must ensure that the ppa points to a cache address */
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BUG_ON(pblk_ppa_empty(ppa));
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BUG_ON(!pblk_addr_in_cache(ppa));
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#endif
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return pblk_rb_copy_to_bio(&pblk->rwb, bio, lba,
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pblk_addr_to_cacheline(ppa), bio_iter);
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}
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static void pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
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unsigned long *read_bitmap)
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{
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struct bio *bio = rqd->bio;
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struct ppa_addr ppas[PBLK_MAX_REQ_ADDRS];
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sector_t blba = pblk_get_lba(bio);
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int nr_secs = rqd->nr_ppas;
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int advanced_bio = 0;
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int i, j = 0;
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/* logic error: lba out-of-bounds. Ignore read request */
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if (blba + nr_secs >= pblk->rl.nr_secs) {
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WARN(1, "pblk: read lbas out of bounds\n");
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return;
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}
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pblk_lookup_l2p_seq(pblk, ppas, blba, nr_secs);
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for (i = 0; i < nr_secs; i++) {
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struct ppa_addr p = ppas[i];
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sector_t lba = blba + i;
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retry:
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if (pblk_ppa_empty(p)) {
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WARN_ON(test_and_set_bit(i, read_bitmap));
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continue;
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}
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/* Try to read from write buffer. The address is later checked
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* on the write buffer to prevent retrieving overwritten data.
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*/
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if (pblk_addr_in_cache(p)) {
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if (!pblk_read_from_cache(pblk, bio, lba, p, i)) {
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pblk_lookup_l2p_seq(pblk, &p, lba, 1);
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goto retry;
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}
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WARN_ON(test_and_set_bit(i, read_bitmap));
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advanced_bio = 1;
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} else {
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/* Read from media non-cached sectors */
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rqd->ppa_list[j++] = p;
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}
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if (advanced_bio)
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bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
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}
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#ifdef CONFIG_NVM_DEBUG
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atomic_long_add(nr_secs, &pblk->inflight_reads);
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#endif
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}
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static int pblk_submit_read_io(struct pblk *pblk, struct nvm_rq *rqd)
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{
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int err;
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rqd->flags = pblk_set_read_mode(pblk);
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err = pblk_submit_io(pblk, rqd);
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if (err)
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return NVM_IO_ERR;
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return NVM_IO_OK;
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}
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static void pblk_end_io_read(struct nvm_rq *rqd)
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{
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struct pblk *pblk = rqd->private;
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struct nvm_tgt_dev *dev = pblk->dev;
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struct pblk_r_ctx *r_ctx = nvm_rq_to_pdu(rqd);
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struct bio *bio = rqd->bio;
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if (rqd->error)
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pblk_log_read_err(pblk, rqd);
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#ifdef CONFIG_NVM_DEBUG
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else
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WARN_ONCE(bio->bi_error, "pblk: corrupted read error\n");
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#endif
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if (rqd->nr_ppas > 1)
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nvm_dev_dma_free(dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
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bio_put(bio);
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if (r_ctx->orig_bio) {
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#ifdef CONFIG_NVM_DEBUG
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WARN_ONCE(r_ctx->orig_bio->bi_error,
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"pblk: corrupted read bio\n");
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#endif
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bio_endio(r_ctx->orig_bio);
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bio_put(r_ctx->orig_bio);
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}
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#ifdef CONFIG_NVM_DEBUG
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atomic_long_add(rqd->nr_ppas, &pblk->sync_reads);
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atomic_long_sub(rqd->nr_ppas, &pblk->inflight_reads);
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#endif
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pblk_free_rqd(pblk, rqd, READ);
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}
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static int pblk_fill_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
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unsigned int bio_init_idx,
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unsigned long *read_bitmap)
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{
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struct bio *new_bio, *bio = rqd->bio;
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struct bio_vec src_bv, dst_bv;
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void *ppa_ptr = NULL;
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void *src_p, *dst_p;
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dma_addr_t dma_ppa_list = 0;
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int nr_secs = rqd->nr_ppas;
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int nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
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int i, ret, hole;
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DECLARE_COMPLETION_ONSTACK(wait);
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new_bio = bio_alloc(GFP_KERNEL, nr_holes);
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if (!new_bio) {
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pr_err("pblk: could not alloc read bio\n");
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return NVM_IO_ERR;
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}
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if (pblk_bio_add_pages(pblk, new_bio, GFP_KERNEL, nr_holes))
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goto err;
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if (nr_holes != new_bio->bi_vcnt) {
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pr_err("pblk: malformed bio\n");
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goto err;
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}
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new_bio->bi_iter.bi_sector = 0; /* internal bio */
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bio_set_op_attrs(new_bio, REQ_OP_READ, 0);
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new_bio->bi_private = &wait;
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new_bio->bi_end_io = pblk_end_bio_sync;
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rqd->bio = new_bio;
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rqd->nr_ppas = nr_holes;
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rqd->end_io = NULL;
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if (unlikely(nr_secs > 1 && nr_holes == 1)) {
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ppa_ptr = rqd->ppa_list;
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dma_ppa_list = rqd->dma_ppa_list;
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rqd->ppa_addr = rqd->ppa_list[0];
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}
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ret = pblk_submit_read_io(pblk, rqd);
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if (ret) {
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bio_put(rqd->bio);
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pr_err("pblk: read IO submission failed\n");
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goto err;
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}
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if (!wait_for_completion_io_timeout(&wait,
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msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
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pr_err("pblk: partial read I/O timed out\n");
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}
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if (rqd->error) {
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atomic_long_inc(&pblk->read_failed);
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#ifdef CONFIG_NVM_DEBUG
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pblk_print_failed_rqd(pblk, rqd, rqd->error);
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#endif
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}
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if (unlikely(nr_secs > 1 && nr_holes == 1)) {
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rqd->ppa_list = ppa_ptr;
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rqd->dma_ppa_list = dma_ppa_list;
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}
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/* Fill the holes in the original bio */
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i = 0;
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hole = find_first_zero_bit(read_bitmap, nr_secs);
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do {
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src_bv = new_bio->bi_io_vec[i++];
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dst_bv = bio->bi_io_vec[bio_init_idx + hole];
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src_p = kmap_atomic(src_bv.bv_page);
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dst_p = kmap_atomic(dst_bv.bv_page);
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memcpy(dst_p + dst_bv.bv_offset,
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src_p + src_bv.bv_offset,
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PBLK_EXPOSED_PAGE_SIZE);
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kunmap_atomic(src_p);
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kunmap_atomic(dst_p);
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mempool_free(src_bv.bv_page, pblk->page_pool);
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hole = find_next_zero_bit(read_bitmap, nr_secs, hole + 1);
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} while (hole < nr_secs);
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bio_put(new_bio);
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/* Complete the original bio and associated request */
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rqd->bio = bio;
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rqd->nr_ppas = nr_secs;
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rqd->private = pblk;
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bio_endio(bio);
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pblk_end_io_read(rqd);
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return NVM_IO_OK;
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err:
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/* Free allocated pages in new bio */
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pblk_bio_free_pages(pblk, bio, 0, new_bio->bi_vcnt);
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rqd->private = pblk;
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pblk_end_io_read(rqd);
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return NVM_IO_ERR;
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}
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static void pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd,
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unsigned long *read_bitmap)
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{
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struct bio *bio = rqd->bio;
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struct ppa_addr ppa;
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sector_t lba = pblk_get_lba(bio);
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/* logic error: lba out-of-bounds. Ignore read request */
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if (lba >= pblk->rl.nr_secs) {
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WARN(1, "pblk: read lba out of bounds\n");
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return;
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}
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pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
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#ifdef CONFIG_NVM_DEBUG
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atomic_long_inc(&pblk->inflight_reads);
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#endif
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retry:
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if (pblk_ppa_empty(ppa)) {
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WARN_ON(test_and_set_bit(0, read_bitmap));
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return;
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}
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/* Try to read from write buffer. The address is later checked on the
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* write buffer to prevent retrieving overwritten data.
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*/
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if (pblk_addr_in_cache(ppa)) {
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if (!pblk_read_from_cache(pblk, bio, lba, ppa, 0)) {
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pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
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goto retry;
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}
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WARN_ON(test_and_set_bit(0, read_bitmap));
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} else {
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rqd->ppa_addr = ppa;
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}
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}
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int pblk_submit_read(struct pblk *pblk, struct bio *bio)
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{
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struct nvm_tgt_dev *dev = pblk->dev;
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unsigned int nr_secs = pblk_get_secs(bio);
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struct nvm_rq *rqd;
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unsigned long read_bitmap; /* Max 64 ppas per request */
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unsigned int bio_init_idx;
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int ret = NVM_IO_ERR;
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if (nr_secs > PBLK_MAX_REQ_ADDRS)
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return NVM_IO_ERR;
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bitmap_zero(&read_bitmap, nr_secs);
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rqd = pblk_alloc_rqd(pblk, READ);
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if (IS_ERR(rqd)) {
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pr_err_ratelimited("pblk: not able to alloc rqd");
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return NVM_IO_ERR;
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}
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rqd->opcode = NVM_OP_PREAD;
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rqd->bio = bio;
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rqd->nr_ppas = nr_secs;
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rqd->private = pblk;
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rqd->end_io = pblk_end_io_read;
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/* Save the index for this bio's start. This is needed in case
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* we need to fill a partial read.
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*/
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bio_init_idx = pblk_get_bi_idx(bio);
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if (nr_secs > 1) {
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rqd->ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
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&rqd->dma_ppa_list);
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if (!rqd->ppa_list) {
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pr_err("pblk: not able to allocate ppa list\n");
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goto fail_rqd_free;
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}
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pblk_read_ppalist_rq(pblk, rqd, &read_bitmap);
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} else {
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pblk_read_rq(pblk, rqd, &read_bitmap);
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}
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bio_get(bio);
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if (bitmap_full(&read_bitmap, nr_secs)) {
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bio_endio(bio);
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pblk_end_io_read(rqd);
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return NVM_IO_OK;
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}
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/* All sectors are to be read from the device */
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if (bitmap_empty(&read_bitmap, rqd->nr_ppas)) {
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struct bio *int_bio = NULL;
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struct pblk_r_ctx *r_ctx = nvm_rq_to_pdu(rqd);
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/* Clone read bio to deal with read errors internally */
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int_bio = bio_clone_bioset(bio, GFP_KERNEL, fs_bio_set);
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if (!int_bio) {
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pr_err("pblk: could not clone read bio\n");
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return NVM_IO_ERR;
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}
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rqd->bio = int_bio;
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r_ctx->orig_bio = bio;
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ret = pblk_submit_read_io(pblk, rqd);
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if (ret) {
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pr_err("pblk: read IO submission failed\n");
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if (int_bio)
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bio_put(int_bio);
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return ret;
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}
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return NVM_IO_OK;
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}
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/* The read bio request could be partially filled by the write buffer,
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* but there are some holes that need to be read from the drive.
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*/
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ret = pblk_fill_partial_read_bio(pblk, rqd, bio_init_idx, &read_bitmap);
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if (ret) {
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pr_err("pblk: failed to perform partial read\n");
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return ret;
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}
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return NVM_IO_OK;
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fail_rqd_free:
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pblk_free_rqd(pblk, rqd, READ);
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return ret;
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}
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static int read_ppalist_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
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struct pblk_line *line, u64 *lba_list,
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unsigned int nr_secs)
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{
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struct ppa_addr ppas[PBLK_MAX_REQ_ADDRS];
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int valid_secs = 0;
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int i;
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pblk_lookup_l2p_rand(pblk, ppas, lba_list, nr_secs);
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for (i = 0; i < nr_secs; i++) {
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if (pblk_addr_in_cache(ppas[i]) || ppas[i].g.blk != line->id ||
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pblk_ppa_empty(ppas[i])) {
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lba_list[i] = ADDR_EMPTY;
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continue;
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}
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rqd->ppa_list[valid_secs++] = ppas[i];
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}
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#ifdef CONFIG_NVM_DEBUG
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atomic_long_add(valid_secs, &pblk->inflight_reads);
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#endif
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return valid_secs;
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}
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static int read_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
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struct pblk_line *line, sector_t lba)
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{
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struct ppa_addr ppa;
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int valid_secs = 0;
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if (lba == ADDR_EMPTY)
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goto out;
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/* logic error: lba out-of-bounds */
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if (lba >= pblk->rl.nr_secs) {
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WARN(1, "pblk: read lba out of bounds\n");
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goto out;
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}
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spin_lock(&pblk->trans_lock);
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ppa = pblk_trans_map_get(pblk, lba);
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spin_unlock(&pblk->trans_lock);
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/* Ignore updated values until the moment */
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if (pblk_addr_in_cache(ppa) || ppa.g.blk != line->id ||
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pblk_ppa_empty(ppa))
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goto out;
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rqd->ppa_addr = ppa;
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valid_secs = 1;
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#ifdef CONFIG_NVM_DEBUG
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atomic_long_inc(&pblk->inflight_reads);
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#endif
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out:
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return valid_secs;
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}
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int pblk_submit_read_gc(struct pblk *pblk, u64 *lba_list, void *data,
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unsigned int nr_secs, unsigned int *secs_to_gc,
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struct pblk_line *line)
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{
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struct nvm_tgt_dev *dev = pblk->dev;
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struct nvm_geo *geo = &dev->geo;
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struct request_queue *q = dev->q;
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struct bio *bio;
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struct nvm_rq rqd;
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int ret, data_len;
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DECLARE_COMPLETION_ONSTACK(wait);
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memset(&rqd, 0, sizeof(struct nvm_rq));
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if (nr_secs > 1) {
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rqd.ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
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&rqd.dma_ppa_list);
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if (!rqd.ppa_list)
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return NVM_IO_ERR;
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*secs_to_gc = read_ppalist_rq_gc(pblk, &rqd, line, lba_list,
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nr_secs);
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if (*secs_to_gc == 1) {
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struct ppa_addr ppa;
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ppa = rqd.ppa_list[0];
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nvm_dev_dma_free(dev->parent, rqd.ppa_list,
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rqd.dma_ppa_list);
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rqd.ppa_addr = ppa;
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}
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} else {
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*secs_to_gc = read_rq_gc(pblk, &rqd, line, lba_list[0]);
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}
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if (!(*secs_to_gc))
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goto out;
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data_len = (*secs_to_gc) * geo->sec_size;
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bio = bio_map_kern(q, data, data_len, GFP_KERNEL);
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if (IS_ERR(bio)) {
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pr_err("pblk: could not allocate GC bio (%lu)\n", PTR_ERR(bio));
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goto err_free_dma;
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}
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bio->bi_iter.bi_sector = 0; /* internal bio */
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bio_set_op_attrs(bio, REQ_OP_READ, 0);
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rqd.opcode = NVM_OP_PREAD;
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rqd.end_io = pblk_end_io_sync;
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rqd.private = &wait;
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rqd.nr_ppas = *secs_to_gc;
|
|
rqd.bio = bio;
|
|
|
|
ret = pblk_submit_read_io(pblk, &rqd);
|
|
if (ret) {
|
|
bio_endio(bio);
|
|
pr_err("pblk: GC read request failed\n");
|
|
goto err_free_dma;
|
|
}
|
|
|
|
if (!wait_for_completion_io_timeout(&wait,
|
|
msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
|
|
pr_err("pblk: GC read I/O timed out\n");
|
|
}
|
|
|
|
if (rqd.error) {
|
|
atomic_long_inc(&pblk->read_failed_gc);
|
|
#ifdef CONFIG_NVM_DEBUG
|
|
pblk_print_failed_rqd(pblk, &rqd, rqd.error);
|
|
#endif
|
|
}
|
|
|
|
#ifdef CONFIG_NVM_DEBUG
|
|
atomic_long_add(*secs_to_gc, &pblk->sync_reads);
|
|
atomic_long_add(*secs_to_gc, &pblk->recov_gc_reads);
|
|
atomic_long_sub(*secs_to_gc, &pblk->inflight_reads);
|
|
#endif
|
|
|
|
out:
|
|
if (rqd.nr_ppas > 1)
|
|
nvm_dev_dma_free(dev->parent, rqd.ppa_list, rqd.dma_ppa_list);
|
|
return NVM_IO_OK;
|
|
|
|
err_free_dma:
|
|
if (rqd.nr_ppas > 1)
|
|
nvm_dev_dma_free(dev->parent, rqd.ppa_list, rqd.dma_ppa_list);
|
|
return NVM_IO_ERR;
|
|
}
|