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

[zhanchengbin <zhanchengbin1@xxxxxxxxxx>]

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@xxxxxxxxxx>
> > ---
> >   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
>
> .