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author | Kent Overstreet <kent.overstreet@gmail.com> | 2017-03-16 22:18:50 -0800 |
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committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-22 17:08:07 -0400 |
commit | 1c6fdbd8f2465ddfb73a01ec620cbf3d14044e1a (patch) | |
tree | 9192de91a00908ee898bc331ac8b0544d6fc030a /fs/bcachefs/checksum.c | |
parent | 0d29a833b7b1800bd2759bbc064b5ada4729caf5 (diff) | |
download | linux-1c6fdbd8f2465ddfb73a01ec620cbf3d14044e1a.tar.gz linux-1c6fdbd8f2465ddfb73a01ec620cbf3d14044e1a.tar.bz2 linux-1c6fdbd8f2465ddfb73a01ec620cbf3d14044e1a.zip |
bcachefs: Initial commit
Initially forked from drivers/md/bcache, bcachefs is a new copy-on-write
filesystem with every feature you could possibly want.
Website: https://bcachefs.org
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/checksum.c')
-rw-r--r-- | fs/bcachefs/checksum.c | 753 |
1 files changed, 753 insertions, 0 deletions
diff --git a/fs/bcachefs/checksum.c b/fs/bcachefs/checksum.c new file mode 100644 index 000000000000..3733cbfa1c91 --- /dev/null +++ b/fs/bcachefs/checksum.c @@ -0,0 +1,753 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "bcachefs.h" +#include "checksum.h" +#include "super.h" +#include "super-io.h" + +#include <linux/crc32c.h> +#include <linux/crypto.h> +#include <linux/key.h> +#include <linux/random.h> +#include <linux/scatterlist.h> +#include <crypto/algapi.h> +#include <crypto/chacha.h> +#include <crypto/hash.h> +#include <crypto/poly1305.h> +#include <crypto/skcipher.h> +#include <keys/user-type.h> + +/* + * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any + * use permitted, subject to terms of PostgreSQL license; see.) + + * If we have a 64-bit integer type, then a 64-bit CRC looks just like the + * usual sort of implementation. (See Ross Williams' excellent introduction + * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from + * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.) + * If we have no working 64-bit type, then fake it with two 32-bit registers. + * + * The present implementation is a normal (not "reflected", in Williams' + * terms) 64-bit CRC, using initial all-ones register contents and a final + * bit inversion. The chosen polynomial is borrowed from the DLT1 spec + * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM): + * + * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 + + * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 + + * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 + + * x^7 + x^4 + x + 1 +*/ + +static const u64 crc_table[256] = { + 0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL, + 0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL, + 0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL, + 0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL, + 0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL, + 0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL, + 0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL, + 0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL, + 0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL, + 0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL, + 0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL, + 0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL, + 0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL, + 0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL, + 0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL, + 0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL, + 0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL, + 0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL, + 0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL, + 0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL, + 0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL, + 0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL, + 0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL, + 0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL, + 0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL, + 0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL, + 0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL, + 0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL, + 0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL, + 0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL, + 0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL, + 0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL, + 0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL, + 0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL, + 0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL, + 0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL, + 0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL, + 0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL, + 0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL, + 0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL, + 0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL, + 0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL, + 0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL, + 0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL, + 0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL, + 0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL, + 0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL, + 0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL, + 0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL, + 0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL, + 0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL, + 0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL, + 0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL, + 0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL, + 0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL, + 0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL, + 0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL, + 0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL, + 0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL, + 0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL, + 0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL, + 0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL, + 0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL, + 0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL, + 0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL, + 0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL, + 0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL, + 0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL, + 0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL, + 0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL, + 0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL, + 0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL, + 0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL, + 0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL, + 0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL, + 0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL, + 0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL, + 0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL, + 0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL, + 0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL, + 0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL, + 0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL, + 0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL, + 0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL, + 0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL, + 0x9AFCE626CE85B507ULL, +}; + +u64 bch2_crc64_update(u64 crc, const void *_data, size_t len) +{ + const unsigned char *data = _data; + + while (len--) { + int i = ((int) (crc >> 56) ^ *data++) & 0xFF; + crc = crc_table[i] ^ (crc << 8); + } + + return crc; +} + +static u64 bch2_checksum_init(unsigned type) +{ + switch (type) { + case BCH_CSUM_NONE: + return 0; + case BCH_CSUM_CRC32C_NONZERO: + return U32_MAX; + case BCH_CSUM_CRC64_NONZERO: + return U64_MAX; + case BCH_CSUM_CRC32C: + return 0; + case BCH_CSUM_CRC64: + return 0; + default: + BUG(); + } +} + +static u64 bch2_checksum_final(unsigned type, u64 crc) +{ + switch (type) { + case BCH_CSUM_NONE: + return 0; + case BCH_CSUM_CRC32C_NONZERO: + return crc ^ U32_MAX; + case BCH_CSUM_CRC64_NONZERO: + return crc ^ U64_MAX; + case BCH_CSUM_CRC32C: + return crc; + case BCH_CSUM_CRC64: + return crc; + default: + BUG(); + } +} + +static u64 bch2_checksum_update(unsigned type, u64 crc, const void *data, size_t len) +{ + switch (type) { + case BCH_CSUM_NONE: + return 0; + case BCH_CSUM_CRC32C_NONZERO: + case BCH_CSUM_CRC32C: + return crc32c(crc, data, len); + case BCH_CSUM_CRC64_NONZERO: + case BCH_CSUM_CRC64: + return bch2_crc64_update(crc, data, len); + default: + BUG(); + } +} + +static inline void do_encrypt_sg(struct crypto_sync_skcipher *tfm, + struct nonce nonce, + struct scatterlist *sg, size_t len) +{ + SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm); + int ret; + + skcipher_request_set_sync_tfm(req, tfm); + skcipher_request_set_crypt(req, sg, sg, len, nonce.d); + + ret = crypto_skcipher_encrypt(req); + BUG_ON(ret); +} + +static inline void do_encrypt(struct crypto_sync_skcipher *tfm, + struct nonce nonce, + void *buf, size_t len) +{ + struct scatterlist sg; + + sg_init_one(&sg, buf, len); + do_encrypt_sg(tfm, nonce, &sg, len); +} + +int bch2_chacha_encrypt_key(struct bch_key *key, struct nonce nonce, + void *buf, size_t len) +{ + struct crypto_sync_skcipher *chacha20 = + crypto_alloc_sync_skcipher("chacha20", 0, 0); + int ret; + + if (!chacha20) { + pr_err("error requesting chacha20 module: %li", PTR_ERR(chacha20)); + return PTR_ERR(chacha20); + } + + ret = crypto_skcipher_setkey(&chacha20->base, + (void *) key, sizeof(*key)); + if (ret) { + pr_err("crypto_skcipher_setkey() error: %i", ret); + goto err; + } + + do_encrypt(chacha20, nonce, buf, len); +err: + crypto_free_sync_skcipher(chacha20); + return ret; +} + +static void gen_poly_key(struct bch_fs *c, struct shash_desc *desc, + struct nonce nonce) +{ + u8 key[POLY1305_KEY_SIZE]; + + nonce.d[3] ^= BCH_NONCE_POLY; + + memset(key, 0, sizeof(key)); + do_encrypt(c->chacha20, nonce, key, sizeof(key)); + + desc->tfm = c->poly1305; + crypto_shash_init(desc); + crypto_shash_update(desc, key, sizeof(key)); +} + +struct bch_csum bch2_checksum(struct bch_fs *c, unsigned type, + struct nonce nonce, const void *data, size_t len) +{ + switch (type) { + case BCH_CSUM_NONE: + case BCH_CSUM_CRC32C_NONZERO: + case BCH_CSUM_CRC64_NONZERO: + case BCH_CSUM_CRC32C: + case BCH_CSUM_CRC64: { + u64 crc = bch2_checksum_init(type); + + crc = bch2_checksum_update(type, crc, data, len); + crc = bch2_checksum_final(type, crc); + + return (struct bch_csum) { .lo = cpu_to_le64(crc) }; + } + + case BCH_CSUM_CHACHA20_POLY1305_80: + case BCH_CSUM_CHACHA20_POLY1305_128: { + SHASH_DESC_ON_STACK(desc, c->poly1305); + u8 digest[POLY1305_DIGEST_SIZE]; + struct bch_csum ret = { 0 }; + + gen_poly_key(c, desc, nonce); + + crypto_shash_update(desc, data, len); + crypto_shash_final(desc, digest); + + memcpy(&ret, digest, bch_crc_bytes[type]); + return ret; + } + default: + BUG(); + } +} + +void bch2_encrypt(struct bch_fs *c, unsigned type, + struct nonce nonce, void *data, size_t len) +{ + if (!bch2_csum_type_is_encryption(type)) + return; + + do_encrypt(c->chacha20, nonce, data, len); +} + +static struct bch_csum __bch2_checksum_bio(struct bch_fs *c, unsigned type, + struct nonce nonce, struct bio *bio, + struct bvec_iter *iter) +{ + struct bio_vec bv; + + switch (type) { + case BCH_CSUM_NONE: + return (struct bch_csum) { 0 }; + case BCH_CSUM_CRC32C_NONZERO: + case BCH_CSUM_CRC64_NONZERO: + case BCH_CSUM_CRC32C: + case BCH_CSUM_CRC64: { + u64 crc = bch2_checksum_init(type); + +#ifdef CONFIG_HIGHMEM + __bio_for_each_segment(bv, bio, *iter, *iter) { + void *p = kmap_atomic(bv.bv_page) + bv.bv_offset; + crc = bch2_checksum_update(type, + crc, p, bv.bv_len); + kunmap_atomic(p); + } +#else + __bio_for_each_contig_segment(bv, bio, *iter, *iter) + crc = bch2_checksum_update(type, crc, + page_address(bv.bv_page) + bv.bv_offset, + bv.bv_len); +#endif + crc = bch2_checksum_final(type, crc); + return (struct bch_csum) { .lo = cpu_to_le64(crc) }; + } + + case BCH_CSUM_CHACHA20_POLY1305_80: + case BCH_CSUM_CHACHA20_POLY1305_128: { + SHASH_DESC_ON_STACK(desc, c->poly1305); + u8 digest[POLY1305_DIGEST_SIZE]; + struct bch_csum ret = { 0 }; + + gen_poly_key(c, desc, nonce); + +#ifdef CONFIG_HIGHMEM + __bio_for_each_segment(bv, bio, *iter, *iter) { + void *p = kmap_atomic(bv.bv_page) + bv.bv_offset; + + crypto_shash_update(desc, p, bv.bv_len); + kunmap_atomic(p); + } +#else + __bio_for_each_contig_segment(bv, bio, *iter, *iter) + crypto_shash_update(desc, + page_address(bv.bv_page) + bv.bv_offset, + bv.bv_len); +#endif + crypto_shash_final(desc, digest); + + memcpy(&ret, digest, bch_crc_bytes[type]); + return ret; + } + default: + BUG(); + } +} + +struct bch_csum bch2_checksum_bio(struct bch_fs *c, unsigned type, + struct nonce nonce, struct bio *bio) +{ + struct bvec_iter iter = bio->bi_iter; + + return __bch2_checksum_bio(c, type, nonce, bio, &iter); +} + +void bch2_encrypt_bio(struct bch_fs *c, unsigned type, + struct nonce nonce, struct bio *bio) +{ + struct bio_vec bv; + struct bvec_iter iter; + struct scatterlist sgl[16], *sg = sgl; + size_t bytes = 0; + + if (!bch2_csum_type_is_encryption(type)) + return; + + sg_init_table(sgl, ARRAY_SIZE(sgl)); + + bio_for_each_segment(bv, bio, iter) { + if (sg == sgl + ARRAY_SIZE(sgl)) { + sg_mark_end(sg - 1); + do_encrypt_sg(c->chacha20, nonce, sgl, bytes); + + nonce = nonce_add(nonce, bytes); + bytes = 0; + + sg_init_table(sgl, ARRAY_SIZE(sgl)); + sg = sgl; + } + + sg_set_page(sg++, bv.bv_page, bv.bv_len, bv.bv_offset); + bytes += bv.bv_len; + } + + sg_mark_end(sg - 1); + do_encrypt_sg(c->chacha20, nonce, sgl, bytes); +} + +static inline bool bch2_checksum_mergeable(unsigned type) +{ + + switch (type) { + case BCH_CSUM_NONE: + case BCH_CSUM_CRC32C: + case BCH_CSUM_CRC64: + return true; + default: + return false; + } +} + +static struct bch_csum bch2_checksum_merge(unsigned type, + struct bch_csum a, + struct bch_csum b, size_t b_len) +{ + BUG_ON(!bch2_checksum_mergeable(type)); + + while (b_len) { + unsigned b = min_t(unsigned, b_len, PAGE_SIZE); + + a.lo = bch2_checksum_update(type, a.lo, + page_address(ZERO_PAGE(0)), b); + b_len -= b; + } + + a.lo ^= b.lo; + a.hi ^= b.hi; + return a; +} + +int bch2_rechecksum_bio(struct bch_fs *c, struct bio *bio, + struct bversion version, + struct bch_extent_crc_unpacked crc_old, + struct bch_extent_crc_unpacked *crc_a, + struct bch_extent_crc_unpacked *crc_b, + unsigned len_a, unsigned len_b, + unsigned new_csum_type) +{ + struct bvec_iter iter = bio->bi_iter; + struct nonce nonce = extent_nonce(version, crc_old); + struct bch_csum merged = { 0 }; + struct crc_split { + struct bch_extent_crc_unpacked *crc; + unsigned len; + unsigned csum_type; + struct bch_csum csum; + } splits[3] = { + { crc_a, len_a, new_csum_type }, + { crc_b, len_b, new_csum_type }, + { NULL, bio_sectors(bio) - len_a - len_b, new_csum_type }, + }, *i; + bool mergeable = crc_old.csum_type == new_csum_type && + bch2_checksum_mergeable(new_csum_type); + unsigned crc_nonce = crc_old.nonce; + + BUG_ON(len_a + len_b > bio_sectors(bio)); + BUG_ON(crc_old.uncompressed_size != bio_sectors(bio)); + BUG_ON(crc_old.compression_type); + BUG_ON(bch2_csum_type_is_encryption(crc_old.csum_type) != + bch2_csum_type_is_encryption(new_csum_type)); + + for (i = splits; i < splits + ARRAY_SIZE(splits); i++) { + iter.bi_size = i->len << 9; + if (mergeable || i->crc) + i->csum = __bch2_checksum_bio(c, i->csum_type, + nonce, bio, &iter); + else + bio_advance_iter(bio, &iter, i->len << 9); + nonce = nonce_add(nonce, i->len << 9); + } + + if (mergeable) + for (i = splits; i < splits + ARRAY_SIZE(splits); i++) + merged = bch2_checksum_merge(new_csum_type, merged, + i->csum, i->len << 9); + else + merged = bch2_checksum_bio(c, crc_old.csum_type, + extent_nonce(version, crc_old), bio); + + if (bch2_crc_cmp(merged, crc_old.csum)) + return -EIO; + + for (i = splits; i < splits + ARRAY_SIZE(splits); i++) { + if (i->crc) + *i->crc = (struct bch_extent_crc_unpacked) { + .csum_type = i->csum_type, + .compressed_size = i->len, + .uncompressed_size = i->len, + .offset = 0, + .live_size = i->len, + .nonce = crc_nonce, + .csum = i->csum, + }; + + if (bch2_csum_type_is_encryption(new_csum_type)) + crc_nonce += i->len; + } + + return 0; +} + +#ifdef __KERNEL__ +int bch2_request_key(struct bch_sb *sb, struct bch_key *key) +{ + char key_description[60]; + struct key *keyring_key; + const struct user_key_payload *ukp; + int ret; + + snprintf(key_description, sizeof(key_description), + "bcachefs:%pUb", &sb->user_uuid); + + keyring_key = request_key(&key_type_logon, key_description, NULL); + if (IS_ERR(keyring_key)) + return PTR_ERR(keyring_key); + + down_read(&keyring_key->sem); + ukp = dereference_key_locked(keyring_key); + if (ukp->datalen == sizeof(*key)) { + memcpy(key, ukp->data, ukp->datalen); + ret = 0; + } else { + ret = -EINVAL; + } + up_read(&keyring_key->sem); + key_put(keyring_key); + + return ret; +} +#else +#include <keyutils.h> +#include <uuid/uuid.h> + +int bch2_request_key(struct bch_sb *sb, struct bch_key *key) +{ + key_serial_t key_id; + char key_description[60]; + char uuid[40]; + + uuid_unparse_lower(sb->user_uuid.b, uuid); + sprintf(key_description, "bcachefs:%s", uuid); + + key_id = request_key("user", key_description, NULL, + KEY_SPEC_USER_KEYRING); + if (key_id < 0) + return -errno; + + if (keyctl_read(key_id, (void *) key, sizeof(*key)) != sizeof(*key)) + return -1; + + return 0; +} +#endif + +int bch2_decrypt_sb_key(struct bch_fs *c, + struct bch_sb_field_crypt *crypt, + struct bch_key *key) +{ + struct bch_encrypted_key sb_key = crypt->key; + struct bch_key user_key; + int ret = 0; + + /* is key encrypted? */ + if (!bch2_key_is_encrypted(&sb_key)) + goto out; + + ret = bch2_request_key(c->disk_sb.sb, &user_key); + if (ret) { + bch_err(c, "error requesting encryption key: %i", ret); + goto err; + } + + /* decrypt real key: */ + ret = bch2_chacha_encrypt_key(&user_key, bch2_sb_key_nonce(c), + &sb_key, sizeof(sb_key)); + if (ret) + goto err; + + if (bch2_key_is_encrypted(&sb_key)) { + bch_err(c, "incorrect encryption key"); + ret = -EINVAL; + goto err; + } +out: + *key = sb_key.key; +err: + memzero_explicit(&sb_key, sizeof(sb_key)); + memzero_explicit(&user_key, sizeof(user_key)); + return ret; +} + +static int bch2_alloc_ciphers(struct bch_fs *c) +{ + if (!c->chacha20) + c->chacha20 = crypto_alloc_sync_skcipher("chacha20", 0, 0); + if (IS_ERR(c->chacha20)) { + bch_err(c, "error requesting chacha20 module: %li", + PTR_ERR(c->chacha20)); + return PTR_ERR(c->chacha20); + } + + if (!c->poly1305) + c->poly1305 = crypto_alloc_shash("poly1305", 0, 0); + if (IS_ERR(c->poly1305)) { + bch_err(c, "error requesting poly1305 module: %li", + PTR_ERR(c->poly1305)); + return PTR_ERR(c->poly1305); + } + + return 0; +} + +int bch2_disable_encryption(struct bch_fs *c) +{ + struct bch_sb_field_crypt *crypt; + struct bch_key key; + int ret = -EINVAL; + + mutex_lock(&c->sb_lock); + + crypt = bch2_sb_get_crypt(c->disk_sb.sb); + if (!crypt) + goto out; + + /* is key encrypted? */ + ret = 0; + if (bch2_key_is_encrypted(&crypt->key)) + goto out; + + ret = bch2_decrypt_sb_key(c, crypt, &key); + if (ret) + goto out; + + crypt->key.magic = BCH_KEY_MAGIC; + crypt->key.key = key; + + SET_BCH_SB_ENCRYPTION_TYPE(c->disk_sb.sb, 0); + bch2_write_super(c); +out: + mutex_unlock(&c->sb_lock); + + return ret; +} + +int bch2_enable_encryption(struct bch_fs *c, bool keyed) +{ + struct bch_encrypted_key key; + struct bch_key user_key; + struct bch_sb_field_crypt *crypt; + int ret = -EINVAL; + + mutex_lock(&c->sb_lock); + + /* Do we already have an encryption key? */ + if (bch2_sb_get_crypt(c->disk_sb.sb)) + goto err; + + ret = bch2_alloc_ciphers(c); + if (ret) + goto err; + + key.magic = BCH_KEY_MAGIC; + get_random_bytes(&key.key, sizeof(key.key)); + + if (keyed) { + ret = bch2_request_key(c->disk_sb.sb, &user_key); + if (ret) { + bch_err(c, "error requesting encryption key: %i", ret); + goto err; + } + + ret = bch2_chacha_encrypt_key(&user_key, bch2_sb_key_nonce(c), + &key, sizeof(key)); + if (ret) + goto err; + } + + ret = crypto_skcipher_setkey(&c->chacha20->base, + (void *) &key.key, sizeof(key.key)); + if (ret) + goto err; + + crypt = bch2_sb_resize_crypt(&c->disk_sb, sizeof(*crypt) / sizeof(u64)); + if (!crypt) { + ret = -ENOMEM; /* XXX this technically could be -ENOSPC */ + goto err; + } + + crypt->key = key; + + /* write superblock */ + SET_BCH_SB_ENCRYPTION_TYPE(c->disk_sb.sb, 1); + bch2_write_super(c); +err: + mutex_unlock(&c->sb_lock); + memzero_explicit(&user_key, sizeof(user_key)); + memzero_explicit(&key, sizeof(key)); + return ret; +} + +void bch2_fs_encryption_exit(struct bch_fs *c) +{ + if (!IS_ERR_OR_NULL(c->poly1305)) + crypto_free_shash(c->poly1305); + if (!IS_ERR_OR_NULL(c->chacha20)) + crypto_free_sync_skcipher(c->chacha20); + if (!IS_ERR_OR_NULL(c->sha256)) + crypto_free_shash(c->sha256); +} + +int bch2_fs_encryption_init(struct bch_fs *c) +{ + struct bch_sb_field_crypt *crypt; + struct bch_key key; + int ret = 0; + + pr_verbose_init(c->opts, ""); + + c->sha256 = crypto_alloc_shash("sha256", 0, 0); + if (IS_ERR(c->sha256)) { + bch_err(c, "error requesting sha256 module"); + ret = PTR_ERR(c->sha256); + goto out; + } + + crypt = bch2_sb_get_crypt(c->disk_sb.sb); + if (!crypt) + goto out; + + ret = bch2_alloc_ciphers(c); + if (ret) + goto out; + + ret = bch2_decrypt_sb_key(c, crypt, &key); + if (ret) + goto out; + + ret = crypto_skcipher_setkey(&c->chacha20->base, + (void *) &key.key, sizeof(key.key)); + if (ret) + goto out; +out: + memzero_explicit(&key, sizeof(key)); + pr_verbose_init(c->opts, "ret %i", ret); + return ret; +} |