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For now, asynchronous raid6 recovery calculate functions are require common offset for pages. But, we expect them to support different page offset after introducing stripe shared page. Do that by simplily adding page offset where each page address are referred. Then, replace the old interface with the new ones in raid6 and raid6test. Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Song Liu <songliubraving@fb.com>
595 lines
16 KiB
C
595 lines
16 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Asynchronous RAID-6 recovery calculations ASYNC_TX API.
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* Copyright(c) 2009 Intel Corporation
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*
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* based on raid6recov.c:
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* Copyright 2002 H. Peter Anvin
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*/
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#include <linux/kernel.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/dma-mapping.h>
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#include <linux/raid/pq.h>
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#include <linux/async_tx.h>
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#include <linux/dmaengine.h>
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static struct dma_async_tx_descriptor *
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async_sum_product(struct page *dest, unsigned int d_off,
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struct page **srcs, unsigned int *src_offs, unsigned char *coef,
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size_t len, struct async_submit_ctl *submit)
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{
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struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ,
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&dest, 1, srcs, 2, len);
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struct dma_device *dma = chan ? chan->device : NULL;
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struct dmaengine_unmap_data *unmap = NULL;
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const u8 *amul, *bmul;
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u8 ax, bx;
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u8 *a, *b, *c;
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if (dma)
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unmap = dmaengine_get_unmap_data(dma->dev, 3, GFP_NOWAIT);
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if (unmap) {
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struct device *dev = dma->dev;
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dma_addr_t pq[2];
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struct dma_async_tx_descriptor *tx;
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enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P;
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if (submit->flags & ASYNC_TX_FENCE)
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dma_flags |= DMA_PREP_FENCE;
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unmap->addr[0] = dma_map_page(dev, srcs[0], src_offs[0],
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len, DMA_TO_DEVICE);
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unmap->addr[1] = dma_map_page(dev, srcs[1], src_offs[1],
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len, DMA_TO_DEVICE);
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unmap->to_cnt = 2;
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unmap->addr[2] = dma_map_page(dev, dest, d_off,
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len, DMA_BIDIRECTIONAL);
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unmap->bidi_cnt = 1;
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/* engine only looks at Q, but expects it to follow P */
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pq[1] = unmap->addr[2];
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unmap->len = len;
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tx = dma->device_prep_dma_pq(chan, pq, unmap->addr, 2, coef,
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len, dma_flags);
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if (tx) {
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dma_set_unmap(tx, unmap);
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async_tx_submit(chan, tx, submit);
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dmaengine_unmap_put(unmap);
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return tx;
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}
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/* could not get a descriptor, unmap and fall through to
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* the synchronous path
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*/
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dmaengine_unmap_put(unmap);
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}
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/* run the operation synchronously */
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async_tx_quiesce(&submit->depend_tx);
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amul = raid6_gfmul[coef[0]];
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bmul = raid6_gfmul[coef[1]];
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a = page_address(srcs[0]) + src_offs[0];
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b = page_address(srcs[1]) + src_offs[1];
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c = page_address(dest) + d_off;
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while (len--) {
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ax = amul[*a++];
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bx = bmul[*b++];
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*c++ = ax ^ bx;
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}
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return NULL;
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}
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static struct dma_async_tx_descriptor *
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async_mult(struct page *dest, unsigned int d_off, struct page *src,
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unsigned int s_off, u8 coef, size_t len,
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struct async_submit_ctl *submit)
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{
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struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ,
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&dest, 1, &src, 1, len);
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struct dma_device *dma = chan ? chan->device : NULL;
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struct dmaengine_unmap_data *unmap = NULL;
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const u8 *qmul; /* Q multiplier table */
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u8 *d, *s;
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if (dma)
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unmap = dmaengine_get_unmap_data(dma->dev, 3, GFP_NOWAIT);
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if (unmap) {
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dma_addr_t dma_dest[2];
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struct device *dev = dma->dev;
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struct dma_async_tx_descriptor *tx;
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enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P;
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if (submit->flags & ASYNC_TX_FENCE)
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dma_flags |= DMA_PREP_FENCE;
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unmap->addr[0] = dma_map_page(dev, src, s_off,
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len, DMA_TO_DEVICE);
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unmap->to_cnt++;
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unmap->addr[1] = dma_map_page(dev, dest, d_off,
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len, DMA_BIDIRECTIONAL);
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dma_dest[1] = unmap->addr[1];
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unmap->bidi_cnt++;
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unmap->len = len;
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/* this looks funny, but the engine looks for Q at
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* dma_dest[1] and ignores dma_dest[0] as a dest
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* due to DMA_PREP_PQ_DISABLE_P
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*/
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tx = dma->device_prep_dma_pq(chan, dma_dest, unmap->addr,
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1, &coef, len, dma_flags);
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if (tx) {
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dma_set_unmap(tx, unmap);
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dmaengine_unmap_put(unmap);
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async_tx_submit(chan, tx, submit);
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return tx;
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}
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/* could not get a descriptor, unmap and fall through to
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* the synchronous path
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*/
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dmaengine_unmap_put(unmap);
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}
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/* no channel available, or failed to allocate a descriptor, so
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* perform the operation synchronously
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*/
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async_tx_quiesce(&submit->depend_tx);
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qmul = raid6_gfmul[coef];
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d = page_address(dest) + d_off;
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s = page_address(src) + s_off;
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while (len--)
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*d++ = qmul[*s++];
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return NULL;
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}
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static struct dma_async_tx_descriptor *
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__2data_recov_4(int disks, size_t bytes, int faila, int failb,
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struct page **blocks, unsigned int *offs,
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struct async_submit_ctl *submit)
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{
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struct dma_async_tx_descriptor *tx = NULL;
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struct page *p, *q, *a, *b;
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unsigned int p_off, q_off, a_off, b_off;
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struct page *srcs[2];
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unsigned int src_offs[2];
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unsigned char coef[2];
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enum async_tx_flags flags = submit->flags;
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dma_async_tx_callback cb_fn = submit->cb_fn;
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void *cb_param = submit->cb_param;
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void *scribble = submit->scribble;
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p = blocks[disks-2];
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p_off = offs[disks-2];
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q = blocks[disks-1];
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q_off = offs[disks-1];
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a = blocks[faila];
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a_off = offs[faila];
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b = blocks[failb];
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b_off = offs[failb];
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/* in the 4 disk case P + Pxy == P and Q + Qxy == Q */
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/* Dx = A*(P+Pxy) + B*(Q+Qxy) */
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srcs[0] = p;
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src_offs[0] = p_off;
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srcs[1] = q;
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src_offs[1] = q_off;
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coef[0] = raid6_gfexi[failb-faila];
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coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]];
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init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
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tx = async_sum_product(b, b_off, srcs, src_offs, coef, bytes, submit);
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/* Dy = P+Pxy+Dx */
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srcs[0] = p;
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src_offs[0] = p_off;
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srcs[1] = b;
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src_offs[1] = b_off;
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init_async_submit(submit, flags | ASYNC_TX_XOR_ZERO_DST, tx, cb_fn,
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cb_param, scribble);
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tx = async_xor_offs(a, a_off, srcs, src_offs, 2, bytes, submit);
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return tx;
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}
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static struct dma_async_tx_descriptor *
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__2data_recov_5(int disks, size_t bytes, int faila, int failb,
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struct page **blocks, unsigned int *offs,
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struct async_submit_ctl *submit)
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{
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struct dma_async_tx_descriptor *tx = NULL;
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struct page *p, *q, *g, *dp, *dq;
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unsigned int p_off, q_off, g_off, dp_off, dq_off;
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struct page *srcs[2];
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unsigned int src_offs[2];
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unsigned char coef[2];
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enum async_tx_flags flags = submit->flags;
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dma_async_tx_callback cb_fn = submit->cb_fn;
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void *cb_param = submit->cb_param;
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void *scribble = submit->scribble;
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int good_srcs, good, i;
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good_srcs = 0;
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good = -1;
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for (i = 0; i < disks-2; i++) {
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if (blocks[i] == NULL)
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continue;
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if (i == faila || i == failb)
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continue;
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good = i;
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good_srcs++;
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}
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BUG_ON(good_srcs > 1);
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p = blocks[disks-2];
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p_off = offs[disks-2];
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q = blocks[disks-1];
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q_off = offs[disks-1];
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g = blocks[good];
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g_off = offs[good];
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/* Compute syndrome with zero for the missing data pages
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* Use the dead data pages as temporary storage for delta p and
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* delta q
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*/
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dp = blocks[faila];
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dp_off = offs[faila];
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dq = blocks[failb];
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dq_off = offs[failb];
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init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
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tx = async_memcpy(dp, g, dp_off, g_off, bytes, submit);
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init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
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tx = async_mult(dq, dq_off, g, g_off,
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raid6_gfexp[good], bytes, submit);
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/* compute P + Pxy */
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srcs[0] = dp;
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src_offs[0] = dp_off;
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srcs[1] = p;
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src_offs[1] = p_off;
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init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
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NULL, NULL, scribble);
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tx = async_xor_offs(dp, dp_off, srcs, src_offs, 2, bytes, submit);
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/* compute Q + Qxy */
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srcs[0] = dq;
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src_offs[0] = dq_off;
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srcs[1] = q;
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src_offs[1] = q_off;
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init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
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NULL, NULL, scribble);
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tx = async_xor_offs(dq, dq_off, srcs, src_offs, 2, bytes, submit);
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/* Dx = A*(P+Pxy) + B*(Q+Qxy) */
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srcs[0] = dp;
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src_offs[0] = dp_off;
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srcs[1] = dq;
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src_offs[1] = dq_off;
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coef[0] = raid6_gfexi[failb-faila];
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coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]];
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init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
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tx = async_sum_product(dq, dq_off, srcs, src_offs, coef, bytes, submit);
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/* Dy = P+Pxy+Dx */
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srcs[0] = dp;
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src_offs[0] = dp_off;
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srcs[1] = dq;
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src_offs[1] = dq_off;
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init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn,
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cb_param, scribble);
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tx = async_xor_offs(dp, dp_off, srcs, src_offs, 2, bytes, submit);
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return tx;
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}
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static struct dma_async_tx_descriptor *
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__2data_recov_n(int disks, size_t bytes, int faila, int failb,
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struct page **blocks, unsigned int *offs,
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struct async_submit_ctl *submit)
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{
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struct dma_async_tx_descriptor *tx = NULL;
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struct page *p, *q, *dp, *dq;
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unsigned int p_off, q_off, dp_off, dq_off;
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struct page *srcs[2];
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unsigned int src_offs[2];
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unsigned char coef[2];
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enum async_tx_flags flags = submit->flags;
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dma_async_tx_callback cb_fn = submit->cb_fn;
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void *cb_param = submit->cb_param;
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void *scribble = submit->scribble;
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p = blocks[disks-2];
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p_off = offs[disks-2];
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q = blocks[disks-1];
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q_off = offs[disks-1];
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/* Compute syndrome with zero for the missing data pages
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* Use the dead data pages as temporary storage for
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* delta p and delta q
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*/
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dp = blocks[faila];
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dp_off = offs[faila];
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blocks[faila] = NULL;
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blocks[disks-2] = dp;
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offs[disks-2] = dp_off;
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dq = blocks[failb];
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dq_off = offs[failb];
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blocks[failb] = NULL;
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blocks[disks-1] = dq;
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offs[disks-1] = dq_off;
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init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
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tx = async_gen_syndrome(blocks, offs, disks, bytes, submit);
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/* Restore pointer table */
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blocks[faila] = dp;
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offs[faila] = dp_off;
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blocks[failb] = dq;
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offs[failb] = dq_off;
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blocks[disks-2] = p;
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offs[disks-2] = p_off;
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blocks[disks-1] = q;
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offs[disks-1] = q_off;
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/* compute P + Pxy */
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srcs[0] = dp;
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src_offs[0] = dp_off;
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srcs[1] = p;
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src_offs[1] = p_off;
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init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
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NULL, NULL, scribble);
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tx = async_xor_offs(dp, dp_off, srcs, src_offs, 2, bytes, submit);
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/* compute Q + Qxy */
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srcs[0] = dq;
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src_offs[0] = dq_off;
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srcs[1] = q;
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src_offs[1] = q_off;
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init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
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NULL, NULL, scribble);
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tx = async_xor_offs(dq, dq_off, srcs, src_offs, 2, bytes, submit);
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/* Dx = A*(P+Pxy) + B*(Q+Qxy) */
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srcs[0] = dp;
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src_offs[0] = dp_off;
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srcs[1] = dq;
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src_offs[1] = dq_off;
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coef[0] = raid6_gfexi[failb-faila];
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coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]];
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init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
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tx = async_sum_product(dq, dq_off, srcs, src_offs, coef, bytes, submit);
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/* Dy = P+Pxy+Dx */
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srcs[0] = dp;
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src_offs[0] = dp_off;
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srcs[1] = dq;
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src_offs[1] = dq_off;
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init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn,
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cb_param, scribble);
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tx = async_xor_offs(dp, dp_off, srcs, src_offs, 2, bytes, submit);
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return tx;
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}
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/**
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* async_raid6_2data_recov - asynchronously calculate two missing data blocks
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* @disks: number of disks in the RAID-6 array
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* @bytes: block size
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* @faila: first failed drive index
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* @failb: second failed drive index
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* @blocks: array of source pointers where the last two entries are p and q
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* @offs: array of offset for pages in blocks
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* @submit: submission/completion modifiers
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*/
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struct dma_async_tx_descriptor *
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async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
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struct page **blocks, unsigned int *offs,
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struct async_submit_ctl *submit)
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{
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void *scribble = submit->scribble;
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int non_zero_srcs, i;
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BUG_ON(faila == failb);
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if (failb < faila)
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swap(faila, failb);
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pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes);
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/* if a dma resource is not available or a scribble buffer is not
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* available punt to the synchronous path. In the 'dma not
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* available' case be sure to use the scribble buffer to
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* preserve the content of 'blocks' as the caller intended.
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*/
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if (!async_dma_find_channel(DMA_PQ) || !scribble) {
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void **ptrs = scribble ? scribble : (void **) blocks;
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async_tx_quiesce(&submit->depend_tx);
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for (i = 0; i < disks; i++)
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if (blocks[i] == NULL)
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ptrs[i] = (void *) raid6_empty_zero_page;
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else
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ptrs[i] = page_address(blocks[i]) + offs[i];
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raid6_2data_recov(disks, bytes, faila, failb, ptrs);
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async_tx_sync_epilog(submit);
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return NULL;
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}
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non_zero_srcs = 0;
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for (i = 0; i < disks-2 && non_zero_srcs < 4; i++)
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if (blocks[i])
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non_zero_srcs++;
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switch (non_zero_srcs) {
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case 0:
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case 1:
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/* There must be at least 2 sources - the failed devices. */
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BUG();
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case 2:
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/* dma devices do not uniformly understand a zero source pq
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* operation (in contrast to the synchronous case), so
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* explicitly handle the special case of a 4 disk array with
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* both data disks missing.
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*/
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return __2data_recov_4(disks, bytes, faila, failb,
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blocks, offs, submit);
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case 3:
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|
/* dma devices do not uniformly understand a single
|
|
* source pq operation (in contrast to the synchronous
|
|
* case), so explicitly handle the special case of a 5 disk
|
|
* array with 2 of 3 data disks missing.
|
|
*/
|
|
return __2data_recov_5(disks, bytes, faila, failb,
|
|
blocks, offs, submit);
|
|
default:
|
|
return __2data_recov_n(disks, bytes, faila, failb,
|
|
blocks, offs, submit);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(async_raid6_2data_recov);
|
|
|
|
/**
|
|
* async_raid6_datap_recov - asynchronously calculate a data and the 'p' block
|
|
* @disks: number of disks in the RAID-6 array
|
|
* @bytes: block size
|
|
* @faila: failed drive index
|
|
* @blocks: array of source pointers where the last two entries are p and q
|
|
* @offs: array of offset for pages in blocks
|
|
* @submit: submission/completion modifiers
|
|
*/
|
|
struct dma_async_tx_descriptor *
|
|
async_raid6_datap_recov(int disks, size_t bytes, int faila,
|
|
struct page **blocks, unsigned int *offs,
|
|
struct async_submit_ctl *submit)
|
|
{
|
|
struct dma_async_tx_descriptor *tx = NULL;
|
|
struct page *p, *q, *dq;
|
|
unsigned int p_off, q_off, dq_off;
|
|
u8 coef;
|
|
enum async_tx_flags flags = submit->flags;
|
|
dma_async_tx_callback cb_fn = submit->cb_fn;
|
|
void *cb_param = submit->cb_param;
|
|
void *scribble = submit->scribble;
|
|
int good_srcs, good, i;
|
|
struct page *srcs[2];
|
|
unsigned int src_offs[2];
|
|
|
|
pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes);
|
|
|
|
/* if a dma resource is not available or a scribble buffer is not
|
|
* available punt to the synchronous path. In the 'dma not
|
|
* available' case be sure to use the scribble buffer to
|
|
* preserve the content of 'blocks' as the caller intended.
|
|
*/
|
|
if (!async_dma_find_channel(DMA_PQ) || !scribble) {
|
|
void **ptrs = scribble ? scribble : (void **) blocks;
|
|
|
|
async_tx_quiesce(&submit->depend_tx);
|
|
for (i = 0; i < disks; i++)
|
|
if (blocks[i] == NULL)
|
|
ptrs[i] = (void*)raid6_empty_zero_page;
|
|
else
|
|
ptrs[i] = page_address(blocks[i]) + offs[i];
|
|
|
|
raid6_datap_recov(disks, bytes, faila, ptrs);
|
|
|
|
async_tx_sync_epilog(submit);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
good_srcs = 0;
|
|
good = -1;
|
|
for (i = 0; i < disks-2; i++) {
|
|
if (i == faila)
|
|
continue;
|
|
if (blocks[i]) {
|
|
good = i;
|
|
good_srcs++;
|
|
if (good_srcs > 1)
|
|
break;
|
|
}
|
|
}
|
|
BUG_ON(good_srcs == 0);
|
|
|
|
p = blocks[disks-2];
|
|
p_off = offs[disks-2];
|
|
q = blocks[disks-1];
|
|
q_off = offs[disks-1];
|
|
|
|
/* Compute syndrome with zero for the missing data page
|
|
* Use the dead data page as temporary storage for delta q
|
|
*/
|
|
dq = blocks[faila];
|
|
dq_off = offs[faila];
|
|
blocks[faila] = NULL;
|
|
blocks[disks-1] = dq;
|
|
offs[disks-1] = dq_off;
|
|
|
|
/* in the 4-disk case we only need to perform a single source
|
|
* multiplication with the one good data block.
|
|
*/
|
|
if (good_srcs == 1) {
|
|
struct page *g = blocks[good];
|
|
unsigned int g_off = offs[good];
|
|
|
|
init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL,
|
|
scribble);
|
|
tx = async_memcpy(p, g, p_off, g_off, bytes, submit);
|
|
|
|
init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL,
|
|
scribble);
|
|
tx = async_mult(dq, dq_off, g, g_off,
|
|
raid6_gfexp[good], bytes, submit);
|
|
} else {
|
|
init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL,
|
|
scribble);
|
|
tx = async_gen_syndrome(blocks, offs, disks, bytes, submit);
|
|
}
|
|
|
|
/* Restore pointer table */
|
|
blocks[faila] = dq;
|
|
offs[faila] = dq_off;
|
|
blocks[disks-1] = q;
|
|
offs[disks-1] = q_off;
|
|
|
|
/* calculate g^{-faila} */
|
|
coef = raid6_gfinv[raid6_gfexp[faila]];
|
|
|
|
srcs[0] = dq;
|
|
src_offs[0] = dq_off;
|
|
srcs[1] = q;
|
|
src_offs[1] = q_off;
|
|
init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
|
|
NULL, NULL, scribble);
|
|
tx = async_xor_offs(dq, dq_off, srcs, src_offs, 2, bytes, submit);
|
|
|
|
init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
|
|
tx = async_mult(dq, dq_off, dq, dq_off, coef, bytes, submit);
|
|
|
|
srcs[0] = p;
|
|
src_offs[0] = p_off;
|
|
srcs[1] = dq;
|
|
src_offs[1] = dq_off;
|
|
init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn,
|
|
cb_param, scribble);
|
|
tx = async_xor_offs(p, p_off, srcs, src_offs, 2, bytes, submit);
|
|
|
|
return tx;
|
|
}
|
|
EXPORT_SYMBOL_GPL(async_raid6_datap_recov);
|
|
|
|
MODULE_AUTHOR("Dan Williams <dan.j.williams@intel.com>");
|
|
MODULE_DESCRIPTION("asynchronous RAID-6 recovery api");
|
|
MODULE_LICENSE("GPL");
|