diff options
Diffstat (limited to 'fs/xfs')
| -rw-r--r-- | fs/xfs/libxfs/xfs_cksum.h | 26 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_inode_buf.c | 2 | ||||
| -rw-r--r-- | fs/xfs/xfs_log.c | 2 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_recover.c | 12 |
4 files changed, 31 insertions, 11 deletions
diff --git a/fs/xfs/libxfs/xfs_cksum.h b/fs/xfs/libxfs/xfs_cksum.h index fad1676ad8cd..a416c7cb23ea 100644 --- a/fs/xfs/libxfs/xfs_cksum.h +++ b/fs/xfs/libxfs/xfs_cksum.h @@ -6,10 +6,11 @@ /* * Calculate the intermediate checksum for a buffer that has the CRC field * inside it. The offset of the 32bit crc fields is passed as the - * cksum_offset parameter. + * cksum_offset parameter. We do not modify the buffer during verification, + * hence we have to split the CRC calculation across the cksum_offset. */ static inline __uint32_t -xfs_start_cksum(char *buffer, size_t length, unsigned long cksum_offset) +xfs_start_cksum_safe(char *buffer, size_t length, unsigned long cksum_offset) { __uint32_t zero = 0; __uint32_t crc; @@ -26,6 +27,20 @@ xfs_start_cksum(char *buffer, size_t length, unsigned long cksum_offset) } /* + * Fast CRC method where the buffer is modified. Callers must have exclusive + * access to the buffer while the calculation takes place. + */ +static inline __uint32_t +xfs_start_cksum_update(char *buffer, size_t length, unsigned long cksum_offset) +{ + /* zero the CRC field */ + *(__le32 *)(buffer + cksum_offset) = 0; + + /* single pass CRC calculation for the entire buffer */ + return crc32c(XFS_CRC_SEED, buffer, length); +} + +/* * Convert the intermediate checksum to the final ondisk format. * * The CRC32c calculation uses LE format even on BE machines, but returns the @@ -40,11 +55,14 @@ xfs_end_cksum(__uint32_t crc) /* * Helper to generate the checksum for a buffer. + * + * This modifies the buffer temporarily - callers must have exclusive + * access to the buffer while the calculation takes place. */ static inline void xfs_update_cksum(char *buffer, size_t length, unsigned long cksum_offset) { - __uint32_t crc = xfs_start_cksum(buffer, length, cksum_offset); + __uint32_t crc = xfs_start_cksum_update(buffer, length, cksum_offset); *(__le32 *)(buffer + cksum_offset) = xfs_end_cksum(crc); } @@ -55,7 +73,7 @@ xfs_update_cksum(char *buffer, size_t length, unsigned long cksum_offset) static inline int xfs_verify_cksum(char *buffer, size_t length, unsigned long cksum_offset) { - __uint32_t crc = xfs_start_cksum(buffer, length, cksum_offset); + __uint32_t crc = xfs_start_cksum_safe(buffer, length, cksum_offset); return *(__le32 *)(buffer + cksum_offset) == xfs_end_cksum(crc); } diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index c906e50515f0..9004665d679a 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -444,7 +444,7 @@ xfs_dinode_calc_crc( return; ASSERT(xfs_sb_version_hascrc(&mp->m_sb)); - crc = xfs_start_cksum((char *)dip, mp->m_sb.sb_inodesize, + crc = xfs_start_cksum_update((char *)dip, mp->m_sb.sb_inodesize, XFS_DINODE_CRC_OFF); dip->di_crc = xfs_end_cksum(crc); } diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 3b74fa011bb1..3ebe444eb60f 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1668,7 +1668,7 @@ xlog_cksum( __uint32_t crc; /* first generate the crc for the record header ... */ - crc = xfs_start_cksum((char *)rhead, + crc = xfs_start_cksum_update((char *)rhead, sizeof(struct xlog_rec_header), offsetof(struct xlog_rec_header, h_crc)); diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 9b3d7c76915d..56b7a2f6aaf2 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -5113,19 +5113,21 @@ xlog_recover_process( struct list_head *buffer_list) { int error; + __le32 old_crc = rhead->h_crc; __le32 crc; + crc = xlog_cksum(log, rhead, dp, be32_to_cpu(rhead->h_len)); /* * Nothing else to do if this is a CRC verification pass. Just return * if this a record with a non-zero crc. Unfortunately, mkfs always - * sets h_crc to 0 so we must consider this valid even on v5 supers. + * sets old_crc to 0 so we must consider this valid even on v5 supers. * Otherwise, return EFSBADCRC on failure so the callers up the stack * know precisely what failed. */ if (pass == XLOG_RECOVER_CRCPASS) { - if (rhead->h_crc && crc != rhead->h_crc) + if (old_crc && crc != old_crc) return -EFSBADCRC; return 0; } @@ -5136,11 +5138,11 @@ xlog_recover_process( * zero CRC check prevents warnings from being emitted when upgrading * the kernel from one that does not add CRCs by default. */ - if (crc != rhead->h_crc) { - if (rhead->h_crc || xfs_sb_version_hascrc(&log->l_mp->m_sb)) { + if (crc != old_crc) { + if (old_crc || xfs_sb_version_hascrc(&log->l_mp->m_sb)) { xfs_alert(log->l_mp, "log record CRC mismatch: found 0x%x, expected 0x%x.", - le32_to_cpu(rhead->h_crc), + le32_to_cpu(old_crc), le32_to_cpu(crc)); xfs_hex_dump(dp, 32); } |