logprint: fix wrapped log dump issue

When running xfs/295 on a 512 byte block size filesystem, logprint
fails during checking with a "Bad log record header" error. This is
due to the fact that the log has wrapped and there is partial record
a the start of the log.

logprint doesn't check for this condition, and simply assumes that
the first block in the log contains a log header, and hence aborts
when this case occurs. So we now have a spurious test failure due to
logprint displaying how right this comment is:

/*
 * This code is gross and needs to be rewritten.
 */

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/logprint/log_misc.c b/logprint/log_misc.c
index d08f90068a90f557aae09fa0d29cb8fd6888a3eb..f0987db16f75307179131cfa52afccfeea6243d5 100644 (file)
--- a/logprint/log_misc.c
+++ b/logprint/log_misc.c
@@ -833,7 +833,8 @@ xlog_print_record(int                         fd,
                 int                      *read_type,
                 xfs_caddr_t              *partial_buf,
                 xlog_rec_header_t        *rhead,
-                xlog_rec_ext_header_t    *xhdrs)
+                xlog_rec_ext_header_t    *xhdrs,
+                int                      bad_hdr_warn)
 {
     xfs_caddr_t                buf, ptr;
     int                        read_len, skip;
@@ -1006,11 +1007,17 @@ xlog_print_record(int                     fd,
                        break;
                    }
                    default: {
-                       fprintf(stderr, _("%s: unknown log operation type (%x)\n"),
-                               progname, *(unsigned short *)ptr);
-                       if (print_exit) {
-                               free(buf);
-                               return BAD_HEADER;
+                       if (bad_hdr_warn) {
+                               fprintf(stderr,
+                       _("%s: unknown log operation type (%x)\n"),
+                                       progname, *(unsigned short *)ptr);
+                               if (print_exit) {
+                                       free(buf);
+                                       return BAD_HEADER;
+                               }
+                       } else {
+                               printf(
+                       _("Left over region from split log item\n"));
                        }
                        skip = 0;
                        ptr += be32_to_cpu(op_head->oh_len);
@@ -1028,7 +1035,7 @@ xlog_print_record(int                       fd,
 
 
 int
-xlog_print_rec_head(xlog_rec_header_t *head, int *len)
+xlog_print_rec_head(xlog_rec_header_t *head, int *len, int bad_hdr_warn)
 {
     int i;
     char uub[64];
@@ -1041,9 +1048,10 @@ xlog_print_rec_head(xlog_rec_header_t *head, int *len)
        return ZEROED_LOG;
 
     if (be32_to_cpu(head->h_magicno) != XLOG_HEADER_MAGIC_NUM) {
-       printf(_("Header 0x%x wanted 0x%x\n"),
-               be32_to_cpu(head->h_magicno),
-               XLOG_HEADER_MAGIC_NUM);
+       if (bad_hdr_warn)
+               printf(_("Header 0x%x wanted 0x%x\n"),
+                       be32_to_cpu(head->h_magicno),
+                       XLOG_HEADER_MAGIC_NUM);
        return BAD_HEADER;
     }
 
@@ -1269,8 +1277,9 @@ void xfs_log_print(struct xlog  *log,
     xfs_daddr_t                        zeroed_blkno = 0, cleared_blkno = 0;
     int                                read_type = FULL_READ;
     xfs_caddr_t                        partial_buf;
-    int                        zeroed = 0;
-    int                        cleared = 0;
+    int                                zeroed = 0;
+    int                                cleared = 0;
+    int                                first_hdr_found = 0;
 
     logBBsize = log->l_logBBsize;
 
@@ -1302,7 +1311,7 @@ void xfs_log_print(struct xlog  *log,
            blkno++;
            goto loop;
        }
-       num_ops = xlog_print_rec_head(hdr, &len);
+       num_ops = xlog_print_rec_head(hdr, &len, first_hdr_found);
        blkno++;
 
        if (zeroed && num_ops != ZEROED_LOG) {
@@ -1328,7 +1337,10 @@ void xfs_log_print(struct xlog  *log,
                    cleared_blkno = blkno-1;
                cleared++;
            } else {
-               print_xlog_bad_header(blkno-1, hbuf);
+               if (!first_hdr_found)
+                       block_start = blkno;
+               else
+                       print_xlog_bad_header(blkno-1, hbuf);
            }
 
            goto loop;
@@ -1339,7 +1351,9 @@ void xfs_log_print(struct xlog  *log,
                break;
        }
 
-       error = xlog_print_record(fd, num_ops, len, &read_type, &partial_buf, hdr, xhdrs);
+       error = xlog_print_record(fd, num_ops, len, &read_type, &partial_buf,
+                                 hdr, xhdrs, first_hdr_found);
+       first_hdr_found++;
        switch (error) {
            case 0: {
                blkno += BTOBB(len);
@@ -1415,7 +1429,7 @@ loop:
                blkno++;
                goto loop2;
            }
-           num_ops = xlog_print_rec_head(hdr, &len);
+           num_ops = xlog_print_rec_head(hdr, &len, first_hdr_found);
            blkno++;
 
            if (num_ops == ZEROED_LOG ||
@@ -1444,7 +1458,8 @@ partial_log_read:
                                    &read_type,
                                    &partial_buf,
                                    (xlog_rec_header_t *)hbuf,
-                                   xhdrs);
+                                   xhdrs,
+                                   first_hdr_found);
            if (read_type != FULL_READ)
                len -= read_type;
            read_type = FULL_READ;