https://github.com/torvalds/linux
Revision 0929d8580071c6a1cec1a7916a8f674c243ceee1 authored by Dave Chinner on 19 November 2018, 21:31:10 UTC, committed by Darrick J. Wong on 21 November 2018, 18:10:53 UTC
When we write into an unwritten extent via direct IO, we dirty
metadata on IO completion to convert the unwritten extent to
written. However, when we do the FUA optimisation checks, the inode
may be clean and so we issue a FUA write into the unwritten extent.
This means we then bypass the generic_write_sync() call after
unwritten extent conversion has ben done and we don't force the
modified metadata to stable storage.

This violates O_DSYNC semantics. The window of exposure is a single
IO, as the next DIO write will see the inode has dirty metadata and
hence will not use the FUA optimisation. Calling
generic_write_sync() after completion of the second IO will also
sync the first write and it's metadata.

Fix this by avoiding the FUA optimisation when writing to unwritten
extents.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
1 parent 9230a0b
Raw File
Tip revision: 0929d8580071c6a1cec1a7916a8f674c243ceee1 authored by Dave Chinner on 19 November 2018, 21:31:10 UTC
iomap: FUA is wrong for DIO O_DSYNC writes into unwritten extents
Tip revision: 0929d85
sha512_generic.c
/* SHA-512 code by Jean-Luc Cooke <jlcooke@certainkey.com>
 *
 * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
 * Copyright (c) 2003 Kyle McMartin <kyle@debian.org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 */
#include <crypto/internal/hash.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/crypto.h>
#include <linux/types.h>
#include <crypto/sha.h>
#include <crypto/sha512_base.h>
#include <linux/percpu.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>

const u8 sha384_zero_message_hash[SHA384_DIGEST_SIZE] = {
	0x38, 0xb0, 0x60, 0xa7, 0x51, 0xac, 0x96, 0x38,
	0x4c, 0xd9, 0x32, 0x7e, 0xb1, 0xb1, 0xe3, 0x6a,
	0x21, 0xfd, 0xb7, 0x11, 0x14, 0xbe, 0x07, 0x43,
	0x4c, 0x0c, 0xc7, 0xbf, 0x63, 0xf6, 0xe1, 0xda,
	0x27, 0x4e, 0xde, 0xbf, 0xe7, 0x6f, 0x65, 0xfb,
	0xd5, 0x1a, 0xd2, 0xf1, 0x48, 0x98, 0xb9, 0x5b
};
EXPORT_SYMBOL_GPL(sha384_zero_message_hash);

const u8 sha512_zero_message_hash[SHA512_DIGEST_SIZE] = {
	0xcf, 0x83, 0xe1, 0x35, 0x7e, 0xef, 0xb8, 0xbd,
	0xf1, 0x54, 0x28, 0x50, 0xd6, 0x6d, 0x80, 0x07,
	0xd6, 0x20, 0xe4, 0x05, 0x0b, 0x57, 0x15, 0xdc,
	0x83, 0xf4, 0xa9, 0x21, 0xd3, 0x6c, 0xe9, 0xce,
	0x47, 0xd0, 0xd1, 0x3c, 0x5d, 0x85, 0xf2, 0xb0,
	0xff, 0x83, 0x18, 0xd2, 0x87, 0x7e, 0xec, 0x2f,
	0x63, 0xb9, 0x31, 0xbd, 0x47, 0x41, 0x7a, 0x81,
	0xa5, 0x38, 0x32, 0x7a, 0xf9, 0x27, 0xda, 0x3e
};
EXPORT_SYMBOL_GPL(sha512_zero_message_hash);

static inline u64 Ch(u64 x, u64 y, u64 z)
{
        return z ^ (x & (y ^ z));
}

static inline u64 Maj(u64 x, u64 y, u64 z)
{
        return (x & y) | (z & (x | y));
}

static const u64 sha512_K[80] = {
        0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL,
        0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
        0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL,
        0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
        0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL,
        0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
        0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL,
        0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
        0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL,
        0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
        0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL,
        0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
        0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL,
        0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
        0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL,
        0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
        0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL,
        0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
        0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL,
        0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
        0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL,
        0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
        0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL,
        0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
        0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL,
        0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
        0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL,
};

#define e0(x)       (ror64(x,28) ^ ror64(x,34) ^ ror64(x,39))
#define e1(x)       (ror64(x,14) ^ ror64(x,18) ^ ror64(x,41))
#define s0(x)       (ror64(x, 1) ^ ror64(x, 8) ^ (x >> 7))
#define s1(x)       (ror64(x,19) ^ ror64(x,61) ^ (x >> 6))

static inline void LOAD_OP(int I, u64 *W, const u8 *input)
{
	W[I] = get_unaligned_be64((__u64 *)input + I);
}

static inline void BLEND_OP(int I, u64 *W)
{
	W[I & 15] += s1(W[(I-2) & 15]) + W[(I-7) & 15] + s0(W[(I-15) & 15]);
}

static void
sha512_transform(u64 *state, const u8 *input)
{
	u64 a, b, c, d, e, f, g, h, t1, t2;

	int i;
	u64 W[16];

	/* load the state into our registers */
	a=state[0];   b=state[1];   c=state[2];   d=state[3];
	e=state[4];   f=state[5];   g=state[6];   h=state[7];

	/* now iterate */
	for (i=0; i<80; i+=8) {
		if (!(i & 8)) {
			int j;

			if (i < 16) {
				/* load the input */
				for (j = 0; j < 16; j++)
					LOAD_OP(i + j, W, input);
			} else {
				for (j = 0; j < 16; j++) {
					BLEND_OP(i + j, W);
				}
			}
		}

		t1 = h + e1(e) + Ch(e,f,g) + sha512_K[i  ] + W[(i & 15)];
		t2 = e0(a) + Maj(a,b,c);    d+=t1;    h=t1+t2;
		t1 = g + e1(d) + Ch(d,e,f) + sha512_K[i+1] + W[(i & 15) + 1];
		t2 = e0(h) + Maj(h,a,b);    c+=t1;    g=t1+t2;
		t1 = f + e1(c) + Ch(c,d,e) + sha512_K[i+2] + W[(i & 15) + 2];
		t2 = e0(g) + Maj(g,h,a);    b+=t1;    f=t1+t2;
		t1 = e + e1(b) + Ch(b,c,d) + sha512_K[i+3] + W[(i & 15) + 3];
		t2 = e0(f) + Maj(f,g,h);    a+=t1;    e=t1+t2;
		t1 = d + e1(a) + Ch(a,b,c) + sha512_K[i+4] + W[(i & 15) + 4];
		t2 = e0(e) + Maj(e,f,g);    h+=t1;    d=t1+t2;
		t1 = c + e1(h) + Ch(h,a,b) + sha512_K[i+5] + W[(i & 15) + 5];
		t2 = e0(d) + Maj(d,e,f);    g+=t1;    c=t1+t2;
		t1 = b + e1(g) + Ch(g,h,a) + sha512_K[i+6] + W[(i & 15) + 6];
		t2 = e0(c) + Maj(c,d,e);    f+=t1;    b=t1+t2;
		t1 = a + e1(f) + Ch(f,g,h) + sha512_K[i+7] + W[(i & 15) + 7];
		t2 = e0(b) + Maj(b,c,d);    e+=t1;    a=t1+t2;
	}

	state[0] += a; state[1] += b; state[2] += c; state[3] += d;
	state[4] += e; state[5] += f; state[6] += g; state[7] += h;

	/* erase our data */
	a = b = c = d = e = f = g = h = t1 = t2 = 0;
}

static void sha512_generic_block_fn(struct sha512_state *sst, u8 const *src,
				    int blocks)
{
	while (blocks--) {
		sha512_transform(sst->state, src);
		src += SHA512_BLOCK_SIZE;
	}
}

int crypto_sha512_update(struct shash_desc *desc, const u8 *data,
			unsigned int len)
{
	return sha512_base_do_update(desc, data, len, sha512_generic_block_fn);
}
EXPORT_SYMBOL(crypto_sha512_update);

static int sha512_final(struct shash_desc *desc, u8 *hash)
{
	sha512_base_do_finalize(desc, sha512_generic_block_fn);
	return sha512_base_finish(desc, hash);
}

int crypto_sha512_finup(struct shash_desc *desc, const u8 *data,
			unsigned int len, u8 *hash)
{
	sha512_base_do_update(desc, data, len, sha512_generic_block_fn);
	return sha512_final(desc, hash);
}
EXPORT_SYMBOL(crypto_sha512_finup);

static struct shash_alg sha512_algs[2] = { {
	.digestsize	=	SHA512_DIGEST_SIZE,
	.init		=	sha512_base_init,
	.update		=	crypto_sha512_update,
	.final		=	sha512_final,
	.finup		=	crypto_sha512_finup,
	.descsize	=	sizeof(struct sha512_state),
	.base		=	{
		.cra_name	=	"sha512",
		.cra_driver_name =	"sha512-generic",
		.cra_priority	=	100,
		.cra_blocksize	=	SHA512_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
}, {
	.digestsize	=	SHA384_DIGEST_SIZE,
	.init		=	sha384_base_init,
	.update		=	crypto_sha512_update,
	.final		=	sha512_final,
	.finup		=	crypto_sha512_finup,
	.descsize	=	sizeof(struct sha512_state),
	.base		=	{
		.cra_name	=	"sha384",
		.cra_driver_name =	"sha384-generic",
		.cra_priority	=	100,
		.cra_blocksize	=	SHA384_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
} };

static int __init sha512_generic_mod_init(void)
{
	return crypto_register_shashes(sha512_algs, ARRAY_SIZE(sha512_algs));
}

static void __exit sha512_generic_mod_fini(void)
{
	crypto_unregister_shashes(sha512_algs, ARRAY_SIZE(sha512_algs));
}

module_init(sha512_generic_mod_init);
module_exit(sha512_generic_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA-512 and SHA-384 Secure Hash Algorithms");

MODULE_ALIAS_CRYPTO("sha384");
MODULE_ALIAS_CRYPTO("sha384-generic");
MODULE_ALIAS_CRYPTO("sha512");
MODULE_ALIAS_CRYPTO("sha512-generic");
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