[PATCH 1/4] logprint: use correct ext. header count for unaligned size

[Brian Foster <bfoster@xxxxxxxxxx>]

A log record has 1 record header and up to 7 additional extended record
headers depending on the size of the record. This is required for log
record packing. A header is required for each 32k of record data.

The header count for a particular record is fixed, based on the log
buffer size (h_size) specified in the record header. logprint calculates
the expected extended header count based on h_size, but does not account
for a log buffer size not aligned with 32k. This results in spurious
invalid header count errors for an otherwise valid log. This can be
reproduced by mounting a filesystem with '-o logbsize=16k' and running
xfs_logprint after a subsequent unmount.

Update xlog_print_extended_headers() to incorporate a non-32k aligned
log buffer size in the expected extended record header count
calculation. This is consistent with how the header count is calculated
in the kernel.

Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
---
 logprint/log_misc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/logprint/log_misc.c b/logprint/log_misc.c
index 4cdcbec..7378fe1 100644
--- a/logprint/log_misc.c
+++ b/logprint/log_misc.c
@@ -1294,6 +1294,8 @@ xlog_print_extended_headers(
 
        num_required = howmany(len, XLOG_HEADER_CYCLE_SIZE);
        num_hdrs = be32_to_cpu(hdr->h_size) / XLOG_HEADER_CYCLE_SIZE;
+       if (be32_to_cpu(hdr->h_size) % XLOG_HEADER_CYCLE_SIZE)
+               num_hdrs++;
 
        if (num_required > num_hdrs) {
            print_xlog_bad_reqd_hdrs((*blkno)-1, num_required, num_hdrs);
-- 
2.1.0