From fe985b910e03fd91193f399a1aca9d1ea22c2557 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 27 Oct 2025 08:05:53 +0100 Subject: [PATCH] xfs: remove xlog_in_core_2_t xlog_in_core_2_t is a really odd type, not only is it grossly misnamed because it actually is an on-disk structure, but it also reprents the actual on-disk structure in a rather odd way. A v1 or small v2 log header look like: +-----------------------+ | xlog_record | +-----------------------+ while larger v2 log headers look like: +-----------------------+ | xlog_record | +-----------------------+ | xlog_rec_ext_header | +-------------------+---+ | ..... | +-----------------------+ | xlog_rec_ext_header | +-----------------------+ I.e., the ext headers are a variable sized array at the end of the header. So instead of declaring a union of xlog_rec_header, xlog_rec_ext_header and padding to BBSIZE, add the proper padding to struct struct xlog_rec_header and struct xlog_rec_ext_header, and add a variable sized array of the latter to the former. This also exposes the somewhat unusual scope of the log checksums, which is made explicitly now by adding proper padding and macro designating the actual payload length. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Reviewed-by: Carlos Maiolino Signed-off-by: Carlos Maiolino --- fs/xfs/libxfs/xfs_log_format.h | 31 +++++++++++++++---------------- fs/xfs/libxfs/xfs_ondisk.h | 6 ++++-- fs/xfs/xfs_log.c | 21 ++++++--------------- fs/xfs/xfs_log_priv.h | 3 +-- 4 files changed, 26 insertions(+), 35 deletions(-) diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h index 91a841ea5bb36..4cb69bd285ca1 100644 --- a/fs/xfs/libxfs/xfs_log_format.h +++ b/fs/xfs/libxfs/xfs_log_format.h @@ -126,6 +126,16 @@ struct xlog_op_header { #define XLOG_FMT XLOG_FMT_LINUX_LE #endif +struct xlog_rec_ext_header { + __be32 xh_cycle; /* write cycle of log */ + __be32 xh_cycle_data[XLOG_CYCLE_DATA_SIZE]; + __u8 xh_reserved[252]; +}; + +/* actual ext header payload size for checksumming */ +#define XLOG_REC_EXT_SIZE \ + offsetofend(struct xlog_rec_ext_header, xh_cycle_data) + typedef struct xlog_rec_header { __be32 h_magicno; /* log record (LR) identifier : 4 */ __be32 h_cycle; /* write cycle of log : 4 */ @@ -161,30 +171,19 @@ typedef struct xlog_rec_header { * (little-endian) architectures. */ __u32 h_pad0; + + __u8 h_reserved[184]; + struct xlog_rec_ext_header h_ext[]; } xlog_rec_header_t; #ifdef __i386__ #define XLOG_REC_SIZE offsetofend(struct xlog_rec_header, h_size) -#define XLOG_REC_SIZE_OTHER sizeof(struct xlog_rec_header) +#define XLOG_REC_SIZE_OTHER offsetofend(struct xlog_rec_header, h_pad0) #else -#define XLOG_REC_SIZE sizeof(struct xlog_rec_header) +#define XLOG_REC_SIZE offsetofend(struct xlog_rec_header, h_pad0) #define XLOG_REC_SIZE_OTHER offsetofend(struct xlog_rec_header, h_size) #endif /* __i386__ */ -typedef struct xlog_rec_ext_header { - __be32 xh_cycle; /* write cycle of log : 4 */ - __be32 xh_cycle_data[XLOG_CYCLE_DATA_SIZE]; /* : 256 */ -} xlog_rec_ext_header_t; - -/* - * Quite misnamed, because this union lays out the actual on-disk log buffer. - */ -typedef union xlog_in_core2 { - xlog_rec_header_t hic_header; - xlog_rec_ext_header_t hic_xheader; - char hic_sector[XLOG_HEADER_SIZE]; -} xlog_in_core_2_t; - /* not an on-disk structure, but needed by log recovery in userspace */ struct xfs_log_iovec { void *i_addr; /* beginning address of region */ diff --git a/fs/xfs/libxfs/xfs_ondisk.h b/fs/xfs/libxfs/xfs_ondisk.h index 7bfa3242e2c53..2e9715cc1641d 100644 --- a/fs/xfs/libxfs/xfs_ondisk.h +++ b/fs/xfs/libxfs/xfs_ondisk.h @@ -174,9 +174,11 @@ xfs_check_ondisk_structs(void) XFS_CHECK_STRUCT_SIZE(struct xfs_rud_log_format, 16); XFS_CHECK_STRUCT_SIZE(struct xfs_map_extent, 32); XFS_CHECK_STRUCT_SIZE(struct xfs_phys_extent, 16); - XFS_CHECK_STRUCT_SIZE(struct xlog_rec_header, 328); - XFS_CHECK_STRUCT_SIZE(struct xlog_rec_ext_header, 260); + XFS_CHECK_STRUCT_SIZE(struct xlog_rec_header, 512); + XFS_CHECK_STRUCT_SIZE(struct xlog_rec_ext_header, 512); + XFS_CHECK_OFFSET(struct xlog_rec_header, h_reserved, 328); + XFS_CHECK_OFFSET(struct xlog_rec_ext_header, xh_reserved, 260); XFS_CHECK_OFFSET(struct xfs_bui_log_format, bui_extents, 16); XFS_CHECK_OFFSET(struct xfs_cui_log_format, cui_extents, 16); XFS_CHECK_OFFSET(struct xfs_rui_log_format, rui_extents, 16); diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index acddab467b77e..1fe3abbd3d365 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1526,12 +1526,8 @@ xlog_pack_data( dp += BBSIZE; } - if (xfs_has_logv2(log->l_mp)) { - xlog_in_core_2_t *xhdr = (xlog_in_core_2_t *)iclog->ic_header; - - for (i = 1; i < log->l_iclog_heads; i++) - xhdr[i].hic_xheader.xh_cycle = cycle_lsn; - } + for (i = 0; i < log->l_iclog_heads - 1; i++) + rhead->h_ext[i].xh_cycle = cycle_lsn; } /* @@ -1556,16 +1552,11 @@ xlog_cksum( /* ... then for additional cycle data for v2 logs ... */ if (xfs_has_logv2(log->l_mp)) { - union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead; - int i; - int xheads; + int xheads, i; - xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE); - - for (i = 1; i < xheads; i++) { - crc = crc32c(crc, &xhdr[i].hic_xheader, - sizeof(struct xlog_rec_ext_header)); - } + xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE) - 1; + for (i = 0; i < xheads; i++) + crc = crc32c(crc, &rhead->h_ext[i], XLOG_REC_EXT_SIZE); } /* ... and finally for the payload */ diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index f1aed6e8f7476..ac98ac71152d4 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -716,11 +716,10 @@ xlog_item_space( static inline __be32 *xlog_cycle_data(struct xlog_rec_header *rhead, unsigned i) { if (i >= XLOG_CYCLE_DATA_SIZE) { - xlog_in_core_2_t *xhdr = (xlog_in_core_2_t *)rhead; unsigned j = i / XLOG_CYCLE_DATA_SIZE; unsigned k = i % XLOG_CYCLE_DATA_SIZE; - return &xhdr[j].hic_xheader.xh_cycle_data[k]; + return &rhead->h_ext[j - 1].xh_cycle_data[k]; } return &rhead->h_cycle_data[i]; -- 2.47.3