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![Jaegeuk Kim](/assets/img/avatar_default.png)
commitdf7b59ba92
("dm verity: fix FEC for RS roots unaligned to block size") introduced the possibility for misaligned roots IO relative to the underlying device's logical block size. E.g. Android's default RS roots=2 results in dm_bufio->block_size=1024, which causes the following EIO if the logical block size of the device is 4096, given v->data_dev_block_bits=12: E sd 0 : 0:0:0: [sda] tag#30 request not aligned to the logical block size E blk_update_request: I/O error, dev sda, sector 10368424 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 E device-mapper: verity-fec: 254:8: FEC 9244672: parity read failed (block 18056): -5 Fix this by onlu using f->roots for dm_bufio blocksize IFF it is aligned to v->data_dev_block_bits. Fixes:df7b59ba92
("dm verity: fix FEC for RS roots unaligned to block size") Cc: stable@vger.kernel.org Signed-off-by: Jaegeuk Kim <jaegeuk@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
822 lines
21 KiB
C
822 lines
21 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2015 Google, Inc.
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*
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* Author: Sami Tolvanen <samitolvanen@google.com>
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*/
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#include "dm-verity-fec.h"
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#include <linux/math64.h>
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#define DM_MSG_PREFIX "verity-fec"
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/*
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* If error correction has been configured, returns true.
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*/
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bool verity_fec_is_enabled(struct dm_verity *v)
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{
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return v->fec && v->fec->dev;
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}
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/*
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* Return a pointer to dm_verity_fec_io after dm_verity_io and its variable
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* length fields.
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*/
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static inline struct dm_verity_fec_io *fec_io(struct dm_verity_io *io)
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{
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return (struct dm_verity_fec_io *) verity_io_digest_end(io->v, io);
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}
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/*
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* Return an interleaved offset for a byte in RS block.
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*/
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static inline u64 fec_interleave(struct dm_verity *v, u64 offset)
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{
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u32 mod;
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mod = do_div(offset, v->fec->rsn);
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return offset + mod * (v->fec->rounds << v->data_dev_block_bits);
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}
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/*
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* Decode an RS block using Reed-Solomon.
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*/
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static int fec_decode_rs8(struct dm_verity *v, struct dm_verity_fec_io *fio,
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u8 *data, u8 *fec, int neras)
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{
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int i;
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uint16_t par[DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN];
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for (i = 0; i < v->fec->roots; i++)
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par[i] = fec[i];
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return decode_rs8(fio->rs, data, par, v->fec->rsn, NULL, neras,
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fio->erasures, 0, NULL);
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}
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/*
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* Read error-correcting codes for the requested RS block. Returns a pointer
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* to the data block. Caller is responsible for releasing buf.
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*/
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static u8 *fec_read_parity(struct dm_verity *v, u64 rsb, int index,
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unsigned *offset, struct dm_buffer **buf)
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{
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u64 position, block, rem;
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u8 *res;
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position = (index + rsb) * v->fec->roots;
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block = div64_u64_rem(position, v->fec->io_size, &rem);
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*offset = (unsigned)rem;
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res = dm_bufio_read(v->fec->bufio, block, buf);
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if (IS_ERR(res)) {
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DMERR("%s: FEC %llu: parity read failed (block %llu): %ld",
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v->data_dev->name, (unsigned long long)rsb,
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(unsigned long long)block, PTR_ERR(res));
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*buf = NULL;
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}
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return res;
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}
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/* Loop over each preallocated buffer slot. */
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#define fec_for_each_prealloc_buffer(__i) \
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for (__i = 0; __i < DM_VERITY_FEC_BUF_PREALLOC; __i++)
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/* Loop over each extra buffer slot. */
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#define fec_for_each_extra_buffer(io, __i) \
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for (__i = DM_VERITY_FEC_BUF_PREALLOC; __i < DM_VERITY_FEC_BUF_MAX; __i++)
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/* Loop over each allocated buffer. */
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#define fec_for_each_buffer(io, __i) \
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for (__i = 0; __i < (io)->nbufs; __i++)
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/* Loop over each RS block in each allocated buffer. */
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#define fec_for_each_buffer_rs_block(io, __i, __j) \
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fec_for_each_buffer(io, __i) \
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for (__j = 0; __j < 1 << DM_VERITY_FEC_BUF_RS_BITS; __j++)
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/*
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* Return a pointer to the current RS block when called inside
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* fec_for_each_buffer_rs_block.
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*/
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static inline u8 *fec_buffer_rs_block(struct dm_verity *v,
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struct dm_verity_fec_io *fio,
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unsigned i, unsigned j)
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{
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return &fio->bufs[i][j * v->fec->rsn];
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}
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/*
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* Return an index to the current RS block when called inside
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* fec_for_each_buffer_rs_block.
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*/
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static inline unsigned fec_buffer_rs_index(unsigned i, unsigned j)
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{
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return (i << DM_VERITY_FEC_BUF_RS_BITS) + j;
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}
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/*
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* Decode all RS blocks from buffers and copy corrected bytes into fio->output
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* starting from block_offset.
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*/
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static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio,
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u64 rsb, int byte_index, unsigned block_offset,
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int neras)
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{
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int r, corrected = 0, res;
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struct dm_buffer *buf;
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unsigned n, i, offset;
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u8 *par, *block;
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par = fec_read_parity(v, rsb, block_offset, &offset, &buf);
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if (IS_ERR(par))
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return PTR_ERR(par);
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/*
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* Decode the RS blocks we have in bufs. Each RS block results in
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* one corrected target byte and consumes fec->roots parity bytes.
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*/
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fec_for_each_buffer_rs_block(fio, n, i) {
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block = fec_buffer_rs_block(v, fio, n, i);
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res = fec_decode_rs8(v, fio, block, &par[offset], neras);
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if (res < 0) {
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r = res;
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goto error;
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}
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corrected += res;
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fio->output[block_offset] = block[byte_index];
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block_offset++;
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if (block_offset >= 1 << v->data_dev_block_bits)
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goto done;
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/* read the next block when we run out of parity bytes */
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offset += v->fec->roots;
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if (offset >= v->fec->io_size) {
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dm_bufio_release(buf);
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par = fec_read_parity(v, rsb, block_offset, &offset, &buf);
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if (IS_ERR(par))
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return PTR_ERR(par);
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}
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}
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done:
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r = corrected;
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error:
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dm_bufio_release(buf);
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if (r < 0 && neras)
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DMERR_LIMIT("%s: FEC %llu: failed to correct: %d",
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v->data_dev->name, (unsigned long long)rsb, r);
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else if (r > 0)
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DMWARN_LIMIT("%s: FEC %llu: corrected %d errors",
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v->data_dev->name, (unsigned long long)rsb, r);
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return r;
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}
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/*
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* Locate data block erasures using verity hashes.
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*/
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static int fec_is_erasure(struct dm_verity *v, struct dm_verity_io *io,
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u8 *want_digest, u8 *data)
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{
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if (unlikely(verity_hash(v, verity_io_hash_req(v, io),
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data, 1 << v->data_dev_block_bits,
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verity_io_real_digest(v, io))))
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return 0;
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return memcmp(verity_io_real_digest(v, io), want_digest,
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v->digest_size) != 0;
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}
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/*
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* Read data blocks that are part of the RS block and deinterleave as much as
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* fits into buffers. Check for erasure locations if @neras is non-NULL.
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*/
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static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
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u64 rsb, u64 target, unsigned block_offset,
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int *neras)
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{
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bool is_zero;
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int i, j, target_index = -1;
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struct dm_buffer *buf;
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struct dm_bufio_client *bufio;
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struct dm_verity_fec_io *fio = fec_io(io);
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u64 block, ileaved;
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u8 *bbuf, *rs_block;
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u8 want_digest[HASH_MAX_DIGESTSIZE];
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unsigned n, k;
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if (neras)
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*neras = 0;
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if (WARN_ON(v->digest_size > sizeof(want_digest)))
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return -EINVAL;
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/*
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* read each of the rsn data blocks that are part of the RS block, and
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* interleave contents to available bufs
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*/
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for (i = 0; i < v->fec->rsn; i++) {
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ileaved = fec_interleave(v, rsb * v->fec->rsn + i);
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/*
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* target is the data block we want to correct, target_index is
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* the index of this block within the rsn RS blocks
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*/
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if (ileaved == target)
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target_index = i;
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block = ileaved >> v->data_dev_block_bits;
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bufio = v->fec->data_bufio;
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if (block >= v->data_blocks) {
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block -= v->data_blocks;
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/*
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* blocks outside the area were assumed to contain
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* zeros when encoding data was generated
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*/
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if (unlikely(block >= v->fec->hash_blocks))
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continue;
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block += v->hash_start;
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bufio = v->bufio;
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}
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bbuf = dm_bufio_read(bufio, block, &buf);
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if (IS_ERR(bbuf)) {
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DMWARN_LIMIT("%s: FEC %llu: read failed (%llu): %ld",
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v->data_dev->name,
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(unsigned long long)rsb,
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(unsigned long long)block, PTR_ERR(bbuf));
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/* assume the block is corrupted */
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if (neras && *neras <= v->fec->roots)
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fio->erasures[(*neras)++] = i;
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continue;
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}
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/* locate erasures if the block is on the data device */
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if (bufio == v->fec->data_bufio &&
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verity_hash_for_block(v, io, block, want_digest,
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&is_zero) == 0) {
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/* skip known zero blocks entirely */
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if (is_zero)
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goto done;
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/*
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* skip if we have already found the theoretical
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* maximum number (i.e. fec->roots) of erasures
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*/
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if (neras && *neras <= v->fec->roots &&
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fec_is_erasure(v, io, want_digest, bbuf))
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fio->erasures[(*neras)++] = i;
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}
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/*
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* deinterleave and copy the bytes that fit into bufs,
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* starting from block_offset
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*/
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fec_for_each_buffer_rs_block(fio, n, j) {
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k = fec_buffer_rs_index(n, j) + block_offset;
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if (k >= 1 << v->data_dev_block_bits)
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goto done;
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rs_block = fec_buffer_rs_block(v, fio, n, j);
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rs_block[i] = bbuf[k];
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}
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done:
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dm_bufio_release(buf);
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}
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return target_index;
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}
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/*
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* Allocate RS control structure and FEC buffers from preallocated mempools,
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* and attempt to allocate as many extra buffers as available.
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*/
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static int fec_alloc_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio)
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{
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unsigned n;
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if (!fio->rs)
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fio->rs = mempool_alloc(&v->fec->rs_pool, GFP_NOIO);
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fec_for_each_prealloc_buffer(n) {
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if (fio->bufs[n])
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continue;
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fio->bufs[n] = mempool_alloc(&v->fec->prealloc_pool, GFP_NOWAIT);
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if (unlikely(!fio->bufs[n])) {
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DMERR("failed to allocate FEC buffer");
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return -ENOMEM;
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}
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}
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/* try to allocate the maximum number of buffers */
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fec_for_each_extra_buffer(fio, n) {
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if (fio->bufs[n])
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continue;
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fio->bufs[n] = mempool_alloc(&v->fec->extra_pool, GFP_NOWAIT);
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/* we can manage with even one buffer if necessary */
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if (unlikely(!fio->bufs[n]))
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break;
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}
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fio->nbufs = n;
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if (!fio->output)
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fio->output = mempool_alloc(&v->fec->output_pool, GFP_NOIO);
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return 0;
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}
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/*
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* Initialize buffers and clear erasures. fec_read_bufs() assumes buffers are
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* zeroed before deinterleaving.
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*/
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static void fec_init_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio)
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{
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unsigned n;
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fec_for_each_buffer(fio, n)
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memset(fio->bufs[n], 0, v->fec->rsn << DM_VERITY_FEC_BUF_RS_BITS);
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memset(fio->erasures, 0, sizeof(fio->erasures));
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}
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/*
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* Decode all RS blocks in a single data block and return the target block
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* (indicated by @offset) in fio->output. If @use_erasures is non-zero, uses
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* hashes to locate erasures.
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*/
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static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io,
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struct dm_verity_fec_io *fio, u64 rsb, u64 offset,
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bool use_erasures)
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{
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int r, neras = 0;
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unsigned pos;
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r = fec_alloc_bufs(v, fio);
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if (unlikely(r < 0))
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return r;
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for (pos = 0; pos < 1 << v->data_dev_block_bits; ) {
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fec_init_bufs(v, fio);
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r = fec_read_bufs(v, io, rsb, offset, pos,
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use_erasures ? &neras : NULL);
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if (unlikely(r < 0))
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return r;
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r = fec_decode_bufs(v, fio, rsb, r, pos, neras);
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if (r < 0)
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return r;
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pos += fio->nbufs << DM_VERITY_FEC_BUF_RS_BITS;
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}
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/* Always re-validate the corrected block against the expected hash */
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r = verity_hash(v, verity_io_hash_req(v, io), fio->output,
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1 << v->data_dev_block_bits,
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verity_io_real_digest(v, io));
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if (unlikely(r < 0))
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return r;
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if (memcmp(verity_io_real_digest(v, io), verity_io_want_digest(v, io),
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v->digest_size)) {
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DMERR_LIMIT("%s: FEC %llu: failed to correct (%d erasures)",
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v->data_dev->name, (unsigned long long)rsb, neras);
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return -EILSEQ;
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}
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return 0;
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}
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static int fec_bv_copy(struct dm_verity *v, struct dm_verity_io *io, u8 *data,
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size_t len)
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{
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struct dm_verity_fec_io *fio = fec_io(io);
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memcpy(data, &fio->output[fio->output_pos], len);
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fio->output_pos += len;
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return 0;
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}
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/*
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* Correct errors in a block. Copies corrected block to dest if non-NULL,
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* otherwise to a bio_vec starting from iter.
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*/
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int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io,
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enum verity_block_type type, sector_t block, u8 *dest,
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struct bvec_iter *iter)
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{
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int r;
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struct dm_verity_fec_io *fio = fec_io(io);
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u64 offset, res, rsb;
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if (!verity_fec_is_enabled(v))
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return -EOPNOTSUPP;
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if (fio->level >= DM_VERITY_FEC_MAX_RECURSION) {
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DMWARN_LIMIT("%s: FEC: recursion too deep", v->data_dev->name);
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return -EIO;
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}
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fio->level++;
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if (type == DM_VERITY_BLOCK_TYPE_METADATA)
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block = block - v->hash_start + v->data_blocks;
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|
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/*
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* For RS(M, N), the continuous FEC data is divided into blocks of N
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* bytes. Since block size may not be divisible by N, the last block
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* is zero padded when decoding.
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*
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* Each byte of the block is covered by a different RS(M, N) code,
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* and each code is interleaved over N blocks to make it less likely
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* that bursty corruption will leave us in unrecoverable state.
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*/
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offset = block << v->data_dev_block_bits;
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res = div64_u64(offset, v->fec->rounds << v->data_dev_block_bits);
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|
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/*
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* The base RS block we can feed to the interleaver to find out all
|
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* blocks required for decoding.
|
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*/
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rsb = offset - res * (v->fec->rounds << v->data_dev_block_bits);
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|
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/*
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* Locating erasures is slow, so attempt to recover the block without
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* them first. Do a second attempt with erasures if the corruption is
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* bad enough.
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*/
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r = fec_decode_rsb(v, io, fio, rsb, offset, false);
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if (r < 0) {
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r = fec_decode_rsb(v, io, fio, rsb, offset, true);
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if (r < 0)
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goto done;
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}
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if (dest)
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memcpy(dest, fio->output, 1 << v->data_dev_block_bits);
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else if (iter) {
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fio->output_pos = 0;
|
|
r = verity_for_bv_block(v, io, iter, fec_bv_copy);
|
|
}
|
|
|
|
done:
|
|
fio->level--;
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Clean up per-bio data.
|
|
*/
|
|
void verity_fec_finish_io(struct dm_verity_io *io)
|
|
{
|
|
unsigned n;
|
|
struct dm_verity_fec *f = io->v->fec;
|
|
struct dm_verity_fec_io *fio = fec_io(io);
|
|
|
|
if (!verity_fec_is_enabled(io->v))
|
|
return;
|
|
|
|
mempool_free(fio->rs, &f->rs_pool);
|
|
|
|
fec_for_each_prealloc_buffer(n)
|
|
mempool_free(fio->bufs[n], &f->prealloc_pool);
|
|
|
|
fec_for_each_extra_buffer(fio, n)
|
|
mempool_free(fio->bufs[n], &f->extra_pool);
|
|
|
|
mempool_free(fio->output, &f->output_pool);
|
|
}
|
|
|
|
/*
|
|
* Initialize per-bio data.
|
|
*/
|
|
void verity_fec_init_io(struct dm_verity_io *io)
|
|
{
|
|
struct dm_verity_fec_io *fio = fec_io(io);
|
|
|
|
if (!verity_fec_is_enabled(io->v))
|
|
return;
|
|
|
|
fio->rs = NULL;
|
|
memset(fio->bufs, 0, sizeof(fio->bufs));
|
|
fio->nbufs = 0;
|
|
fio->output = NULL;
|
|
fio->level = 0;
|
|
}
|
|
|
|
/*
|
|
* Append feature arguments and values to the status table.
|
|
*/
|
|
unsigned verity_fec_status_table(struct dm_verity *v, unsigned sz,
|
|
char *result, unsigned maxlen)
|
|
{
|
|
if (!verity_fec_is_enabled(v))
|
|
return sz;
|
|
|
|
DMEMIT(" " DM_VERITY_OPT_FEC_DEV " %s "
|
|
DM_VERITY_OPT_FEC_BLOCKS " %llu "
|
|
DM_VERITY_OPT_FEC_START " %llu "
|
|
DM_VERITY_OPT_FEC_ROOTS " %d",
|
|
v->fec->dev->name,
|
|
(unsigned long long)v->fec->blocks,
|
|
(unsigned long long)v->fec->start,
|
|
v->fec->roots);
|
|
|
|
return sz;
|
|
}
|
|
|
|
void verity_fec_dtr(struct dm_verity *v)
|
|
{
|
|
struct dm_verity_fec *f = v->fec;
|
|
|
|
if (!verity_fec_is_enabled(v))
|
|
goto out;
|
|
|
|
mempool_exit(&f->rs_pool);
|
|
mempool_exit(&f->prealloc_pool);
|
|
mempool_exit(&f->extra_pool);
|
|
mempool_exit(&f->output_pool);
|
|
kmem_cache_destroy(f->cache);
|
|
|
|
if (f->data_bufio)
|
|
dm_bufio_client_destroy(f->data_bufio);
|
|
if (f->bufio)
|
|
dm_bufio_client_destroy(f->bufio);
|
|
|
|
if (f->dev)
|
|
dm_put_device(v->ti, f->dev);
|
|
out:
|
|
kfree(f);
|
|
v->fec = NULL;
|
|
}
|
|
|
|
static void *fec_rs_alloc(gfp_t gfp_mask, void *pool_data)
|
|
{
|
|
struct dm_verity *v = (struct dm_verity *)pool_data;
|
|
|
|
return init_rs_gfp(8, 0x11d, 0, 1, v->fec->roots, gfp_mask);
|
|
}
|
|
|
|
static void fec_rs_free(void *element, void *pool_data)
|
|
{
|
|
struct rs_control *rs = (struct rs_control *)element;
|
|
|
|
if (rs)
|
|
free_rs(rs);
|
|
}
|
|
|
|
bool verity_is_fec_opt_arg(const char *arg_name)
|
|
{
|
|
return (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_DEV) ||
|
|
!strcasecmp(arg_name, DM_VERITY_OPT_FEC_BLOCKS) ||
|
|
!strcasecmp(arg_name, DM_VERITY_OPT_FEC_START) ||
|
|
!strcasecmp(arg_name, DM_VERITY_OPT_FEC_ROOTS));
|
|
}
|
|
|
|
int verity_fec_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
|
|
unsigned *argc, const char *arg_name)
|
|
{
|
|
int r;
|
|
struct dm_target *ti = v->ti;
|
|
const char *arg_value;
|
|
unsigned long long num_ll;
|
|
unsigned char num_c;
|
|
char dummy;
|
|
|
|
if (!*argc) {
|
|
ti->error = "FEC feature arguments require a value";
|
|
return -EINVAL;
|
|
}
|
|
|
|
arg_value = dm_shift_arg(as);
|
|
(*argc)--;
|
|
|
|
if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_DEV)) {
|
|
r = dm_get_device(ti, arg_value, FMODE_READ, &v->fec->dev);
|
|
if (r) {
|
|
ti->error = "FEC device lookup failed";
|
|
return r;
|
|
}
|
|
|
|
} else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_BLOCKS)) {
|
|
if (sscanf(arg_value, "%llu%c", &num_ll, &dummy) != 1 ||
|
|
((sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT))
|
|
>> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll)) {
|
|
ti->error = "Invalid " DM_VERITY_OPT_FEC_BLOCKS;
|
|
return -EINVAL;
|
|
}
|
|
v->fec->blocks = num_ll;
|
|
|
|
} else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_START)) {
|
|
if (sscanf(arg_value, "%llu%c", &num_ll, &dummy) != 1 ||
|
|
((sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) >>
|
|
(v->data_dev_block_bits - SECTOR_SHIFT) != num_ll)) {
|
|
ti->error = "Invalid " DM_VERITY_OPT_FEC_START;
|
|
return -EINVAL;
|
|
}
|
|
v->fec->start = num_ll;
|
|
|
|
} else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_ROOTS)) {
|
|
if (sscanf(arg_value, "%hhu%c", &num_c, &dummy) != 1 || !num_c ||
|
|
num_c < (DM_VERITY_FEC_RSM - DM_VERITY_FEC_MAX_RSN) ||
|
|
num_c > (DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN)) {
|
|
ti->error = "Invalid " DM_VERITY_OPT_FEC_ROOTS;
|
|
return -EINVAL;
|
|
}
|
|
v->fec->roots = num_c;
|
|
|
|
} else {
|
|
ti->error = "Unrecognized verity FEC feature request";
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Allocate dm_verity_fec for v->fec. Must be called before verity_fec_ctr.
|
|
*/
|
|
int verity_fec_ctr_alloc(struct dm_verity *v)
|
|
{
|
|
struct dm_verity_fec *f;
|
|
|
|
f = kzalloc(sizeof(struct dm_verity_fec), GFP_KERNEL);
|
|
if (!f) {
|
|
v->ti->error = "Cannot allocate FEC structure";
|
|
return -ENOMEM;
|
|
}
|
|
v->fec = f;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Validate arguments and preallocate memory. Must be called after arguments
|
|
* have been parsed using verity_fec_parse_opt_args.
|
|
*/
|
|
int verity_fec_ctr(struct dm_verity *v)
|
|
{
|
|
struct dm_verity_fec *f = v->fec;
|
|
struct dm_target *ti = v->ti;
|
|
u64 hash_blocks, fec_blocks;
|
|
int ret;
|
|
|
|
if (!verity_fec_is_enabled(v)) {
|
|
verity_fec_dtr(v);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* FEC is computed over data blocks, possible metadata, and
|
|
* hash blocks. In other words, FEC covers total of fec_blocks
|
|
* blocks consisting of the following:
|
|
*
|
|
* data blocks | hash blocks | metadata (optional)
|
|
*
|
|
* We allow metadata after hash blocks to support a use case
|
|
* where all data is stored on the same device and FEC covers
|
|
* the entire area.
|
|
*
|
|
* If metadata is included, we require it to be available on the
|
|
* hash device after the hash blocks.
|
|
*/
|
|
|
|
hash_blocks = v->hash_blocks - v->hash_start;
|
|
|
|
/*
|
|
* Require matching block sizes for data and hash devices for
|
|
* simplicity.
|
|
*/
|
|
if (v->data_dev_block_bits != v->hash_dev_block_bits) {
|
|
ti->error = "Block sizes must match to use FEC";
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!f->roots) {
|
|
ti->error = "Missing " DM_VERITY_OPT_FEC_ROOTS;
|
|
return -EINVAL;
|
|
}
|
|
f->rsn = DM_VERITY_FEC_RSM - f->roots;
|
|
|
|
if (!f->blocks) {
|
|
ti->error = "Missing " DM_VERITY_OPT_FEC_BLOCKS;
|
|
return -EINVAL;
|
|
}
|
|
|
|
f->rounds = f->blocks;
|
|
if (sector_div(f->rounds, f->rsn))
|
|
f->rounds++;
|
|
|
|
/*
|
|
* Due to optional metadata, f->blocks can be larger than
|
|
* data_blocks and hash_blocks combined.
|
|
*/
|
|
if (f->blocks < v->data_blocks + hash_blocks || !f->rounds) {
|
|
ti->error = "Invalid " DM_VERITY_OPT_FEC_BLOCKS;
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Metadata is accessed through the hash device, so we require
|
|
* it to be large enough.
|
|
*/
|
|
f->hash_blocks = f->blocks - v->data_blocks;
|
|
if (dm_bufio_get_device_size(v->bufio) < f->hash_blocks) {
|
|
ti->error = "Hash device is too small for "
|
|
DM_VERITY_OPT_FEC_BLOCKS;
|
|
return -E2BIG;
|
|
}
|
|
|
|
if ((f->roots << SECTOR_SHIFT) & ((1 << v->data_dev_block_bits) - 1))
|
|
f->io_size = 1 << v->data_dev_block_bits;
|
|
else
|
|
f->io_size = v->fec->roots << SECTOR_SHIFT;
|
|
|
|
f->bufio = dm_bufio_client_create(f->dev->bdev,
|
|
f->io_size,
|
|
1, 0, NULL, NULL);
|
|
if (IS_ERR(f->bufio)) {
|
|
ti->error = "Cannot initialize FEC bufio client";
|
|
return PTR_ERR(f->bufio);
|
|
}
|
|
|
|
dm_bufio_set_sector_offset(f->bufio, f->start << (v->data_dev_block_bits - SECTOR_SHIFT));
|
|
|
|
fec_blocks = div64_u64(f->rounds * f->roots, v->fec->roots << SECTOR_SHIFT);
|
|
if (dm_bufio_get_device_size(f->bufio) < fec_blocks) {
|
|
ti->error = "FEC device is too small";
|
|
return -E2BIG;
|
|
}
|
|
|
|
f->data_bufio = dm_bufio_client_create(v->data_dev->bdev,
|
|
1 << v->data_dev_block_bits,
|
|
1, 0, NULL, NULL);
|
|
if (IS_ERR(f->data_bufio)) {
|
|
ti->error = "Cannot initialize FEC data bufio client";
|
|
return PTR_ERR(f->data_bufio);
|
|
}
|
|
|
|
if (dm_bufio_get_device_size(f->data_bufio) < v->data_blocks) {
|
|
ti->error = "Data device is too small";
|
|
return -E2BIG;
|
|
}
|
|
|
|
/* Preallocate an rs_control structure for each worker thread */
|
|
ret = mempool_init(&f->rs_pool, num_online_cpus(), fec_rs_alloc,
|
|
fec_rs_free, (void *) v);
|
|
if (ret) {
|
|
ti->error = "Cannot allocate RS pool";
|
|
return ret;
|
|
}
|
|
|
|
f->cache = kmem_cache_create("dm_verity_fec_buffers",
|
|
f->rsn << DM_VERITY_FEC_BUF_RS_BITS,
|
|
0, 0, NULL);
|
|
if (!f->cache) {
|
|
ti->error = "Cannot create FEC buffer cache";
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Preallocate DM_VERITY_FEC_BUF_PREALLOC buffers for each thread */
|
|
ret = mempool_init_slab_pool(&f->prealloc_pool, num_online_cpus() *
|
|
DM_VERITY_FEC_BUF_PREALLOC,
|
|
f->cache);
|
|
if (ret) {
|
|
ti->error = "Cannot allocate FEC buffer prealloc pool";
|
|
return ret;
|
|
}
|
|
|
|
ret = mempool_init_slab_pool(&f->extra_pool, 0, f->cache);
|
|
if (ret) {
|
|
ti->error = "Cannot allocate FEC buffer extra pool";
|
|
return ret;
|
|
}
|
|
|
|
/* Preallocate an output buffer for each thread */
|
|
ret = mempool_init_kmalloc_pool(&f->output_pool, num_online_cpus(),
|
|
1 << v->data_dev_block_bits);
|
|
if (ret) {
|
|
ti->error = "Cannot allocate FEC output pool";
|
|
return ret;
|
|
}
|
|
|
|
/* Reserve space for our per-bio data */
|
|
ti->per_io_data_size += sizeof(struct dm_verity_fec_io);
|
|
|
|
return 0;
|
|
}
|