^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2015 Google, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Author: Sami Tolvanen <samitolvanen@google.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include "dm-verity-fec.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/math64.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #define DM_MSG_PREFIX "verity-fec"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * If error correction has been configured, returns true.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) bool verity_fec_is_enabled(struct dm_verity *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) return v->fec && v->fec->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * Return a pointer to dm_verity_fec_io after dm_verity_io and its variable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * length fields.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static inline struct dm_verity_fec_io *fec_io(struct dm_verity_io *io)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) return (struct dm_verity_fec_io *) verity_io_digest_end(io->v, io);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * Return an interleaved offset for a byte in RS block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) static inline u64 fec_interleave(struct dm_verity *v, u64 offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) u32 mod;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) mod = do_div(offset, v->fec->rsn);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) return offset + mod * (v->fec->rounds << v->data_dev_block_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * Decode an RS block using Reed-Solomon.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) static int fec_decode_rs8(struct dm_verity *v, struct dm_verity_fec_io *fio,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) u8 *data, u8 *fec, int neras)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) uint16_t par[DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) for (i = 0; i < v->fec->roots; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) par[i] = fec[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) return decode_rs8(fio->rs, data, par, v->fec->rsn, NULL, neras,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) fio->erasures, 0, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * Read error-correcting codes for the requested RS block. Returns a pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * to the data block. Caller is responsible for releasing buf.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) static u8 *fec_read_parity(struct dm_verity *v, u64 rsb, int index,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) unsigned *offset, struct dm_buffer **buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) u64 position, block, rem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) u8 *res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) position = (index + rsb) * v->fec->roots;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) block = div64_u64_rem(position, v->fec->io_size, &rem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) *offset = (unsigned)rem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) res = dm_bufio_read(v->fec->bufio, block, buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) if (IS_ERR(res)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) DMERR("%s: FEC %llu: parity read failed (block %llu): %ld",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) v->data_dev->name, (unsigned long long)rsb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) (unsigned long long)block, PTR_ERR(res));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) *buf = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) /* Loop over each preallocated buffer slot. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) #define fec_for_each_prealloc_buffer(__i) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) for (__i = 0; __i < DM_VERITY_FEC_BUF_PREALLOC; __i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) /* Loop over each extra buffer slot. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) #define fec_for_each_extra_buffer(io, __i) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) for (__i = DM_VERITY_FEC_BUF_PREALLOC; __i < DM_VERITY_FEC_BUF_MAX; __i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) /* Loop over each allocated buffer. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) #define fec_for_each_buffer(io, __i) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) for (__i = 0; __i < (io)->nbufs; __i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) /* Loop over each RS block in each allocated buffer. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) #define fec_for_each_buffer_rs_block(io, __i, __j) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) fec_for_each_buffer(io, __i) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) for (__j = 0; __j < 1 << DM_VERITY_FEC_BUF_RS_BITS; __j++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * Return a pointer to the current RS block when called inside
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * fec_for_each_buffer_rs_block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) static inline u8 *fec_buffer_rs_block(struct dm_verity *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) struct dm_verity_fec_io *fio,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) unsigned i, unsigned j)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) return &fio->bufs[i][j * v->fec->rsn];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) * Return an index to the current RS block when called inside
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) * fec_for_each_buffer_rs_block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) static inline unsigned fec_buffer_rs_index(unsigned i, unsigned j)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) return (i << DM_VERITY_FEC_BUF_RS_BITS) + j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * Decode all RS blocks from buffers and copy corrected bytes into fio->output
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * starting from block_offset.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) u64 rsb, int byte_index, unsigned block_offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) int neras)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) int r, corrected = 0, res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) struct dm_buffer *buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) unsigned n, i, offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) u8 *par, *block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) par = fec_read_parity(v, rsb, block_offset, &offset, &buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) if (IS_ERR(par))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) return PTR_ERR(par);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * Decode the RS blocks we have in bufs. Each RS block results in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * one corrected target byte and consumes fec->roots parity bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) fec_for_each_buffer_rs_block(fio, n, i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) block = fec_buffer_rs_block(v, fio, n, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) res = fec_decode_rs8(v, fio, block, &par[offset], neras);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) if (res < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) r = res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) corrected += res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) fio->output[block_offset] = block[byte_index];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) block_offset++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) if (block_offset >= 1 << v->data_dev_block_bits)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) goto done;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) /* read the next block when we run out of parity bytes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) offset += v->fec->roots;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) if (offset >= v->fec->io_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) dm_bufio_release(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) par = fec_read_parity(v, rsb, block_offset, &offset, &buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) if (IS_ERR(par))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) return PTR_ERR(par);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) done:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) r = corrected;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) dm_bufio_release(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) if (r < 0 && neras)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) DMERR_LIMIT("%s: FEC %llu: failed to correct: %d",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) v->data_dev->name, (unsigned long long)rsb, r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) else if (r > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) DMWARN_LIMIT("%s: FEC %llu: corrected %d errors",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) v->data_dev->name, (unsigned long long)rsb, r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) * Locate data block erasures using verity hashes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) static int fec_is_erasure(struct dm_verity *v, struct dm_verity_io *io,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) u8 *want_digest, u8 *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) if (unlikely(verity_hash(v, verity_io_hash_req(v, io),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) data, 1 << v->data_dev_block_bits,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) verity_io_real_digest(v, io))))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) return memcmp(verity_io_real_digest(v, io), want_digest,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) v->digest_size) != 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * Read data blocks that are part of the RS block and deinterleave as much as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * fits into buffers. Check for erasure locations if @neras is non-NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) u64 rsb, u64 target, unsigned block_offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) int *neras)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) bool is_zero;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) int i, j, target_index = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) struct dm_buffer *buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) struct dm_bufio_client *bufio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) struct dm_verity_fec_io *fio = fec_io(io);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) u64 block, ileaved;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) u8 *bbuf, *rs_block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) u8 want_digest[HASH_MAX_DIGESTSIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) unsigned n, k;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) if (neras)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) *neras = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) if (WARN_ON(v->digest_size > sizeof(want_digest)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) * read each of the rsn data blocks that are part of the RS block, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * interleave contents to available bufs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) for (i = 0; i < v->fec->rsn; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) ileaved = fec_interleave(v, rsb * v->fec->rsn + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) * target is the data block we want to correct, target_index is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) * the index of this block within the rsn RS blocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) if (ileaved == target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) target_index = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) block = ileaved >> v->data_dev_block_bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) bufio = v->fec->data_bufio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) if (block >= v->data_blocks) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) block -= v->data_blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) * blocks outside the area were assumed to contain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) * zeros when encoding data was generated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) if (unlikely(block >= v->fec->hash_blocks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) block += v->hash_start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) bufio = v->bufio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) bbuf = dm_bufio_read(bufio, block, &buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) if (IS_ERR(bbuf)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) DMWARN_LIMIT("%s: FEC %llu: read failed (%llu): %ld",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) v->data_dev->name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) (unsigned long long)rsb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) (unsigned long long)block, PTR_ERR(bbuf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) /* assume the block is corrupted */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) if (neras && *neras <= v->fec->roots)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) fio->erasures[(*neras)++] = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) /* locate erasures if the block is on the data device */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) if (bufio == v->fec->data_bufio &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) verity_hash_for_block(v, io, block, want_digest,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) &is_zero) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) /* skip known zero blocks entirely */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) if (is_zero)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) goto done;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) * skip if we have already found the theoretical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) * maximum number (i.e. fec->roots) of erasures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) if (neras && *neras <= v->fec->roots &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) fec_is_erasure(v, io, want_digest, bbuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) fio->erasures[(*neras)++] = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) * deinterleave and copy the bytes that fit into bufs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) * starting from block_offset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) fec_for_each_buffer_rs_block(fio, n, j) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) k = fec_buffer_rs_index(n, j) + block_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) if (k >= 1 << v->data_dev_block_bits)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) goto done;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) rs_block = fec_buffer_rs_block(v, fio, n, j);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) rs_block[i] = bbuf[k];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) done:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) dm_bufio_release(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) return target_index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) * Allocate RS control structure and FEC buffers from preallocated mempools,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) * and attempt to allocate as many extra buffers as available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) static int fec_alloc_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) unsigned n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) if (!fio->rs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) fio->rs = mempool_alloc(&v->fec->rs_pool, GFP_NOIO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) fec_for_each_prealloc_buffer(n) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) if (fio->bufs[n])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) fio->bufs[n] = mempool_alloc(&v->fec->prealloc_pool, GFP_NOWAIT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) if (unlikely(!fio->bufs[n])) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) DMERR("failed to allocate FEC buffer");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) /* try to allocate the maximum number of buffers */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) fec_for_each_extra_buffer(fio, n) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) if (fio->bufs[n])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) fio->bufs[n] = mempool_alloc(&v->fec->extra_pool, GFP_NOWAIT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) /* we can manage with even one buffer if necessary */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) if (unlikely(!fio->bufs[n]))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) fio->nbufs = n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) if (!fio->output)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) fio->output = mempool_alloc(&v->fec->output_pool, GFP_NOIO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) * Initialize buffers and clear erasures. fec_read_bufs() assumes buffers are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) * zeroed before deinterleaving.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) static void fec_init_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) unsigned n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) fec_for_each_buffer(fio, n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) memset(fio->bufs[n], 0, v->fec->rsn << DM_VERITY_FEC_BUF_RS_BITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) memset(fio->erasures, 0, sizeof(fio->erasures));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * Decode all RS blocks in a single data block and return the target block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) * (indicated by @offset) in fio->output. If @use_erasures is non-zero, uses
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) * hashes to locate erasures.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) struct dm_verity_fec_io *fio, u64 rsb, u64 offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) bool use_erasures)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) int r, neras = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) unsigned pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) r = fec_alloc_bufs(v, fio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) if (unlikely(r < 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) for (pos = 0; pos < 1 << v->data_dev_block_bits; ) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) fec_init_bufs(v, fio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) r = fec_read_bufs(v, io, rsb, offset, pos,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) use_erasures ? &neras : NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) if (unlikely(r < 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) r = fec_decode_bufs(v, fio, rsb, r, pos, neras);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) if (r < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) pos += fio->nbufs << DM_VERITY_FEC_BUF_RS_BITS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) /* Always re-validate the corrected block against the expected hash */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) r = verity_hash(v, verity_io_hash_req(v, io), fio->output,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 1 << v->data_dev_block_bits,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) verity_io_real_digest(v, io));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) if (unlikely(r < 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) if (memcmp(verity_io_real_digest(v, io), verity_io_want_digest(v, io),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) v->digest_size)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) DMERR_LIMIT("%s: FEC %llu: failed to correct (%d erasures)",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) v->data_dev->name, (unsigned long long)rsb, neras);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) return -EILSEQ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) static int fec_bv_copy(struct dm_verity *v, struct dm_verity_io *io, u8 *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) size_t len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) struct dm_verity_fec_io *fio = fec_io(io);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) memcpy(data, &fio->output[fio->output_pos], len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) fio->output_pos += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) * Correct errors in a block. Copies corrected block to dest if non-NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * otherwise to a bio_vec starting from iter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) enum verity_block_type type, sector_t block, u8 *dest,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) struct bvec_iter *iter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) struct dm_verity_fec_io *fio = fec_io(io);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) u64 offset, res, rsb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) if (!verity_fec_is_enabled(v))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) return -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) if (fio->level >= DM_VERITY_FEC_MAX_RECURSION) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) DMWARN_LIMIT("%s: FEC: recursion too deep", v->data_dev->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) fio->level++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) if (type == DM_VERITY_BLOCK_TYPE_METADATA)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) block = block - v->hash_start + v->data_blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) * For RS(M, N), the continuous FEC data is divided into blocks of N
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) * bytes. Since block size may not be divisible by N, the last block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) * is zero padded when decoding.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) * Each byte of the block is covered by a different RS(M, N) code,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * and each code is interleaved over N blocks to make it less likely
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * that bursty corruption will leave us in unrecoverable state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) offset = block << v->data_dev_block_bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) res = div64_u64(offset, v->fec->rounds << v->data_dev_block_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) * The base RS block we can feed to the interleaver to find out all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) * blocks required for decoding.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) rsb = offset - res * (v->fec->rounds << v->data_dev_block_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) * Locating erasures is slow, so attempt to recover the block without
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) * them first. Do a second attempt with erasures if the corruption is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) * bad enough.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) r = fec_decode_rsb(v, io, fio, rsb, offset, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) if (r < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) r = fec_decode_rsb(v, io, fio, rsb, offset, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) if (r < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) goto done;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) if (dest)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) memcpy(dest, fio->output, 1 << v->data_dev_block_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) else if (iter) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) fio->output_pos = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) r = verity_for_bv_block(v, io, iter, fec_bv_copy);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) done:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) fio->level--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) * Clean up per-bio data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) void verity_fec_finish_io(struct dm_verity_io *io)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) unsigned n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) struct dm_verity_fec *f = io->v->fec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) struct dm_verity_fec_io *fio = fec_io(io);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) if (!verity_fec_is_enabled(io->v))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) mempool_free(fio->rs, &f->rs_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) fec_for_each_prealloc_buffer(n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) mempool_free(fio->bufs[n], &f->prealloc_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) fec_for_each_extra_buffer(fio, n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) mempool_free(fio->bufs[n], &f->extra_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) mempool_free(fio->output, &f->output_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) * Initialize per-bio data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) void verity_fec_init_io(struct dm_verity_io *io)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) struct dm_verity_fec_io *fio = fec_io(io);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) if (!verity_fec_is_enabled(io->v))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) fio->rs = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) memset(fio->bufs, 0, sizeof(fio->bufs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) fio->nbufs = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) fio->output = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) fio->level = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) * Append feature arguments and values to the status table.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) unsigned verity_fec_status_table(struct dm_verity *v, unsigned sz,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) char *result, unsigned maxlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) if (!verity_fec_is_enabled(v))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) return sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) DMEMIT(" " DM_VERITY_OPT_FEC_DEV " %s "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) DM_VERITY_OPT_FEC_BLOCKS " %llu "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) DM_VERITY_OPT_FEC_START " %llu "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) DM_VERITY_OPT_FEC_ROOTS " %d",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) v->fec->dev->name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) (unsigned long long)v->fec->blocks,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) (unsigned long long)v->fec->start,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) v->fec->roots);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) return sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) void verity_fec_dtr(struct dm_verity *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) struct dm_verity_fec *f = v->fec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) if (!verity_fec_is_enabled(v))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) mempool_exit(&f->rs_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) mempool_exit(&f->prealloc_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) mempool_exit(&f->extra_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) mempool_exit(&f->output_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) kmem_cache_destroy(f->cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) if (f->data_bufio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) dm_bufio_client_destroy(f->data_bufio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) if (f->bufio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) dm_bufio_client_destroy(f->bufio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) if (f->dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) dm_put_device(v->ti, f->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) kfree(f);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) v->fec = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) static void *fec_rs_alloc(gfp_t gfp_mask, void *pool_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) struct dm_verity *v = (struct dm_verity *)pool_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) return init_rs_gfp(8, 0x11d, 0, 1, v->fec->roots, gfp_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) static void fec_rs_free(void *element, void *pool_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) struct rs_control *rs = (struct rs_control *)element;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) if (rs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) free_rs(rs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) bool verity_is_fec_opt_arg(const char *arg_name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) return (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_DEV) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) !strcasecmp(arg_name, DM_VERITY_OPT_FEC_BLOCKS) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) !strcasecmp(arg_name, DM_VERITY_OPT_FEC_START) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) !strcasecmp(arg_name, DM_VERITY_OPT_FEC_ROOTS));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) int verity_fec_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) unsigned *argc, const char *arg_name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) struct dm_target *ti = v->ti;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) const char *arg_value;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) unsigned long long num_ll;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) unsigned char num_c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) char dummy;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) if (!*argc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) ti->error = "FEC feature arguments require a value";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) arg_value = dm_shift_arg(as);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) (*argc)--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_DEV)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) r = dm_get_device(ti, arg_value, FMODE_READ, &v->fec->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) if (r) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) ti->error = "FEC device lookup failed";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) } else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_BLOCKS)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) if (sscanf(arg_value, "%llu%c", &num_ll, &dummy) != 1 ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) ((sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) >> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) ti->error = "Invalid " DM_VERITY_OPT_FEC_BLOCKS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) v->fec->blocks = num_ll;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) } else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_START)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) if (sscanf(arg_value, "%llu%c", &num_ll, &dummy) != 1 ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) ((sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) >>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) ti->error = "Invalid " DM_VERITY_OPT_FEC_START;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) v->fec->start = num_ll;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) } else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_ROOTS)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) if (sscanf(arg_value, "%hhu%c", &num_c, &dummy) != 1 || !num_c ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) num_c < (DM_VERITY_FEC_RSM - DM_VERITY_FEC_MAX_RSN) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) num_c > (DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) ti->error = "Invalid " DM_VERITY_OPT_FEC_ROOTS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) v->fec->roots = num_c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) ti->error = "Unrecognized verity FEC feature request";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) * Allocate dm_verity_fec for v->fec. Must be called before verity_fec_ctr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) int verity_fec_ctr_alloc(struct dm_verity *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) struct dm_verity_fec *f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) f = kzalloc(sizeof(struct dm_verity_fec), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) if (!f) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) v->ti->error = "Cannot allocate FEC structure";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) v->fec = f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) * Validate arguments and preallocate memory. Must be called after arguments
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) * have been parsed using verity_fec_parse_opt_args.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) int verity_fec_ctr(struct dm_verity *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) struct dm_verity_fec *f = v->fec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) struct dm_target *ti = v->ti;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) u64 hash_blocks, fec_blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) if (!verity_fec_is_enabled(v)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) verity_fec_dtr(v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) * FEC is computed over data blocks, possible metadata, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) * hash blocks. In other words, FEC covers total of fec_blocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) * blocks consisting of the following:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) * data blocks | hash blocks | metadata (optional)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) * We allow metadata after hash blocks to support a use case
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) * where all data is stored on the same device and FEC covers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) * the entire area.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) * If metadata is included, we require it to be available on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) * hash device after the hash blocks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) hash_blocks = v->hash_blocks - v->hash_start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) * Require matching block sizes for data and hash devices for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) * simplicity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) if (v->data_dev_block_bits != v->hash_dev_block_bits) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) ti->error = "Block sizes must match to use FEC";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) if (!f->roots) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) ti->error = "Missing " DM_VERITY_OPT_FEC_ROOTS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) f->rsn = DM_VERITY_FEC_RSM - f->roots;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) if (!f->blocks) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) ti->error = "Missing " DM_VERITY_OPT_FEC_BLOCKS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) f->rounds = f->blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) if (sector_div(f->rounds, f->rsn))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) f->rounds++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) * Due to optional metadata, f->blocks can be larger than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) * data_blocks and hash_blocks combined.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) if (f->blocks < v->data_blocks + hash_blocks || !f->rounds) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) ti->error = "Invalid " DM_VERITY_OPT_FEC_BLOCKS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) * Metadata is accessed through the hash device, so we require
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) * it to be large enough.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) f->hash_blocks = f->blocks - v->data_blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) if (dm_bufio_get_device_size(v->bufio) < f->hash_blocks) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) ti->error = "Hash device is too small for "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) DM_VERITY_OPT_FEC_BLOCKS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) return -E2BIG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) if ((f->roots << SECTOR_SHIFT) & ((1 << v->data_dev_block_bits) - 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) f->io_size = 1 << v->data_dev_block_bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) f->io_size = v->fec->roots << SECTOR_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) f->bufio = dm_bufio_client_create(f->dev->bdev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) f->io_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) 1, 0, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) if (IS_ERR(f->bufio)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) ti->error = "Cannot initialize FEC bufio client";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) return PTR_ERR(f->bufio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) dm_bufio_set_sector_offset(f->bufio, f->start << (v->data_dev_block_bits - SECTOR_SHIFT));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) fec_blocks = div64_u64(f->rounds * f->roots, v->fec->roots << SECTOR_SHIFT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) if (dm_bufio_get_device_size(f->bufio) < fec_blocks) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) ti->error = "FEC device is too small";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) return -E2BIG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) f->data_bufio = dm_bufio_client_create(v->data_dev->bdev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) 1 << v->data_dev_block_bits,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) 1, 0, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) if (IS_ERR(f->data_bufio)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) ti->error = "Cannot initialize FEC data bufio client";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) return PTR_ERR(f->data_bufio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) if (dm_bufio_get_device_size(f->data_bufio) < v->data_blocks) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) ti->error = "Data device is too small";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) return -E2BIG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) /* Preallocate an rs_control structure for each worker thread */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) ret = mempool_init(&f->rs_pool, num_online_cpus(), fec_rs_alloc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) fec_rs_free, (void *) v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) ti->error = "Cannot allocate RS pool";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) f->cache = kmem_cache_create("dm_verity_fec_buffers",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) f->rsn << DM_VERITY_FEC_BUF_RS_BITS,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) 0, 0, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) if (!f->cache) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) ti->error = "Cannot create FEC buffer cache";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) /* Preallocate DM_VERITY_FEC_BUF_PREALLOC buffers for each thread */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) ret = mempool_init_slab_pool(&f->prealloc_pool, num_online_cpus() *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) DM_VERITY_FEC_BUF_PREALLOC,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) f->cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) ti->error = "Cannot allocate FEC buffer prealloc pool";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) ret = mempool_init_slab_pool(&f->extra_pool, 0, f->cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) ti->error = "Cannot allocate FEC buffer extra pool";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) /* Preallocate an output buffer for each thread */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) ret = mempool_init_kmalloc_pool(&f->output_pool, num_online_cpus(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) 1 << v->data_dev_block_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) ti->error = "Cannot allocate FEC output pool";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) /* Reserve space for our per-bio data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) ti->per_io_data_size += sizeof(struct dm_verity_fec_io);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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