From: Dave Chinner <dchinner@xxxxxxxxxx> As demonstrated by xfs/295, continuation transactions cause of problems for xfs_logprint. The failure demonstrated by the test is that the buffer log format structures are variable sized on disk - the dirty bitmap is sized according to the buffer length, not fixed to the length of the maximum supported buffer size. xfs_logprint assumes that the buf log format reocrds are of fixed size, and so when a short buffer is found it fails to handle it properly and treats it like a continuation record. This causses the opheader pointer to be incremented incorrectly and then logprint wanders off into a dark corner and gets eaten by a grue. While fixing this, make the xlog_print_record code that does the transaction opheader walking a little easier to read and stop it from outputting binary data direct to the console by converting the no-data-print case to use a hex dumping loop. Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> --- logprint/log_misc.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/logprint/log_misc.c b/logprint/log_misc.c index 30b7ea6..d08f900 100644 --- a/logprint/log_misc.c +++ b/logprint/log_misc.c @@ -268,7 +268,13 @@ xlog_print_trans_buffer(xfs_caddr_t *ptr, int len, int *i, int num_ops) blen = f->blf_len; map_size = f->blf_map_size; flags = f->blf_flags; - struct_size = sizeof(xfs_buf_log_format_t); + + /* + * size of the format header is dependent on the size of the bitmap, not + * the size of the in-memory structure. Hence the slightly obtuse + * calculation. + */ + struct_size = offsetof(struct xfs_buf_log_format, blf_map_size) + map_size; if (len >= struct_size) { ASSERT((len - sizeof(struct_size)) % sizeof(int) == 0); @@ -933,22 +939,28 @@ xlog_print_record(int fd, continued = ((op_head->oh_flags & XLOG_WAS_CONT_TRANS) || (op_head->oh_flags & XLOG_CONTINUE_TRANS)); - /* print transaction data */ - if (print_no_data || - (continued && be32_to_cpu(op_head->oh_len) == 0)) { + if (continued && be32_to_cpu(op_head->oh_len) == 0) + continue; + + if (print_no_data) { for (n = 0; n < be32_to_cpu(op_head->oh_len); n++) { - printf("%c", *ptr); + printf("0x%02x ", (unsigned int)*ptr); + if (n % 16 == 15) + printf("\n"); ptr++; } printf("\n"); continue; } + + /* print transaction data */ if (xlog_print_find_tid(be32_to_cpu(op_head->oh_tid), op_head->oh_flags & XLOG_WAS_CONT_TRANS)) { printf(_("Left over region from split log item\n")); ptr += be32_to_cpu(op_head->oh_len); continue; } + if (be32_to_cpu(op_head->oh_len) != 0) { if (*(uint *)ptr == XFS_TRANS_HEADER_MAGIC) { skip = xlog_print_trans_header(&ptr, _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs