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27 March 2024, 02:37:15 UTC
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 
iomap: FUA is wrong for DIO O_DSYNC writes into unwritten extents
 
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
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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
ripemd.h 
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Common values for RIPEMD algorithms
 */

#ifndef _CRYPTO_RMD_H
#define _CRYPTO_RMD_H

#define RMD128_DIGEST_SIZE      16
#define RMD128_BLOCK_SIZE       64

#define RMD160_DIGEST_SIZE      20
#define RMD160_BLOCK_SIZE       64

#define RMD256_DIGEST_SIZE      32
#define RMD256_BLOCK_SIZE       64

#define RMD320_DIGEST_SIZE      40
#define RMD320_BLOCK_SIZE       64

/* initial values  */
#define RMD_H0  0x67452301UL
#define RMD_H1  0xefcdab89UL
#define RMD_H2  0x98badcfeUL
#define RMD_H3  0x10325476UL
#define RMD_H4  0xc3d2e1f0UL
#define RMD_H5  0x76543210UL
#define RMD_H6  0xfedcba98UL
#define RMD_H7  0x89abcdefUL
#define RMD_H8  0x01234567UL
#define RMD_H9  0x3c2d1e0fUL

/* constants */
#define RMD_K1  0x00000000UL
#define RMD_K2  0x5a827999UL
#define RMD_K3  0x6ed9eba1UL
#define RMD_K4  0x8f1bbcdcUL
#define RMD_K5  0xa953fd4eUL
#define RMD_K6  0x50a28be6UL
#define RMD_K7  0x5c4dd124UL
#define RMD_K8  0x6d703ef3UL
#define RMD_K9  0x7a6d76e9UL

#endif
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