Re: [PATCH] debugfs/logdump.c: Add parameter t to dump sequence commit timestamps

[zhanchengbin <zhanchengbin1@huawei.com>]

On 2025/6/30 23:10, Darrick J. Wong wrote:
> On Tue, Jun 17, 2025 at 07:31:35PM +0800, zhanchengbin wrote:
>> When filesystem errors occur, inspect journal sequences with parameter t to
>>   dump commit timestamps.
>>
>> Signed-off-by: zhanchengbin <zhanchengbin@huawei.com>
>> ---
>>   debugfs/logdump.c | 63 ++++++++++++++++++++++++++++++++++++++++-------
>>   1 file changed, 54 insertions(+), 9 deletions(-)
>>
>> diff --git a/debugfs/logdump.c b/debugfs/logdump.c
>> index 324ed42..bbe1384 100644
>> --- a/debugfs/logdump.c
>> +++ b/debugfs/logdump.c
>> @@ -47,7 +47,7 @@ enum journal_location {JOURNAL_IS_INTERNAL,
>> JOURNAL_IS_EXTERNAL};
>>
>>   #define ANY_BLOCK ((blk64_t) -1)
>>
>> -static int        dump_all, dump_super, dump_old, dump_contents,
>> dump_descriptors;
>> +static int        dump_all, dump_super, dump_old, dump_contents,
>> dump_descriptors, dump_time;
>>   static int64_t        dump_counts;
>>   static blk64_t        block_to_dump, bitmap_to_dump, inode_block_to_dump;
>>   static unsigned int    group_to_dump, inode_offset_to_dump;
>> @@ -67,6 +67,8 @@ static void dump_descriptor_block(FILE *, struct
>> journal_source *,
>>                     char *, journal_superblock_t *,
>>                     unsigned int *, unsigned int, __u32, tid_t);
>>
>> +static void dump_commit_time(FILE *out_file, char *buf);
>> +
>>   static void dump_revoke_block(FILE *, char *, journal_superblock_t *,
>>                     unsigned int, unsigned int, tid_t);
>>
>> @@ -118,10 +120,11 @@ void do_logdump(int argc, ss_argv_t argv, int sci_idx
>> EXT2FS_ATTR((unused)),
>>       inode_block_to_dump = ANY_BLOCK;
>>       inode_to_dump = -1;
>>       dump_counts = -1;
>> +    dump_time = 0;
> 
> Globals are initialized to zero if not given an explicit value so this
> isn't necessary.

Okay.

> 
>>       wrapped_flag = false;
>>
>>       reset_getopt();
>> -    while ((c = getopt (argc, argv, "ab:ci:f:OsSn:")) != EOF) {
>> +    while ((c = getopt (argc, argv, "ab:ci:f:OsSn:t")) != EOF) {
>>           switch (c) {
>>           case 'a':
>>               dump_all++;
>> @@ -162,6 +165,9 @@ void do_logdump(int argc, ss_argv_t argv, int sci_idx
>> EXT2FS_ATTR((unused)),
>>                   return;
>>               }
>>               break;
>> +        case 't':
>> +            dump_time++;
>> +            break;
>>           default:
>>               goto print_usage;
>>           }
>> @@ -521,21 +527,33 @@ static void dump_journal(char *cmdname, FILE
>> *out_file,
>>                   break;
>>           }
>>
>> -        if (dump_descriptors) {
>> -            fprintf (out_file, "Found expected sequence %u, "
>> -                 "type %u (%s) at block %u\n",
>> -                 sequence, blocktype,
>> -                 type_to_name(blocktype), blocknr);
>> -        }
>> -
>>           switch (blocktype) {
>>           case JBD2_DESCRIPTOR_BLOCK:
>> +            if (dump_descriptors) {
>> +                fprintf (out_file, "Found expected sequence %u, "
>> +                     "type %u (%s) at block %u\n",
>> +                     sequence, blocktype,
>> +                     type_to_name(blocktype), blocknr);
>> +            }
>> +
>>               dump_descriptor_block(out_file, source, buf, jsb,
>>                             &blocknr, blocksize, maxlen,
>>                             transaction);
>>               continue;
>>
>>           case JBD2_COMMIT_BLOCK:
>> +            if (dump_descriptors) {
>> +                fprintf (out_file, "Found expected sequence %u, "
>> +                     "type %u (%s) at block %u",
>> +                     sequence, blocktype,
>> +                     type_to_name(blocktype), blocknr);
>> +            }
> 
> Why did the "Found expected sequence..." message get moved?

To dump the time after the commit block without a new line.

> 
>> +
>> +            if (dump_time)
>> +                dump_commit_time(out_file, buf);
>> +
>> +            fprintf(out_file, "\n");
>> +
>>               cur_counts++;
>>               transaction++;
>>               blocknr++;
>> @@ -543,6 +561,13 @@ static void dump_journal(char *cmdname, FILE *out_file,
>>               continue;
>>
>>           case JBD2_REVOKE_BLOCK:
>> +            if (dump_descriptors) {
>> +                fprintf (out_file, "Found expected sequence %u, "
>> +                     "type %u (%s) at block %u\n",
>> +                     sequence, blocktype,
>> +                     type_to_name(blocktype), blocknr);
>> +            }
>> +
>>               dump_revoke_block(out_file, buf, jsb,
>>                         blocknr, blocksize,
>>                         transaction);
>> @@ -742,6 +767,26 @@ static void dump_descriptor_block(FILE *out_file,
>>       *blockp = blocknr;
>>   }
>>
>> +static void dump_commit_time(FILE *out_file, char *buf)
>> +{
>> +    struct commit_header    *header;
>> +    __be64        commit_sec;
>> +    time_t        timestamp;
>> +    struct tm    timeinfo;
>> +
>> +    header = (struct commit_header*)buf;
>> +    commit_sec = be64_to_cpu(header->h_commit_sec);
>> +
>> +    timestamp = commit_sec;
>> +    gmtime_r(&timestamp, &timeinfo);
>> +    fprintf(out_file, ", commit at UTC: %04d-%02d-%02d %02d:%02d:%02d",
>> +        timeinfo.tm_year + 1900,
>> +        timeinfo.tm_mon + 1,
>> +        timeinfo.tm_mday,
>> +        timeinfo.tm_hour,
>> +        timeinfo.tm_min,
>> +        timeinfo.tm_sec);
> 
> Use ctime_r() to get a locale-appropriate local timestamp string to
> print out.  Or asctime_r() if you really need UTC.
> 
> --D
> 

I'll try to optimize this and push the patch for the next version.

Thanks,
  - bin.

>> +}
>>
>>   static void dump_revoke_block(FILE *out_file, char *buf,
>>                     journal_superblock_t *jsb EXT2FS_ATTR((unused)),
>> -- 
>> 2.33.0
>>
> 
> .
>