On 5/23/17 10:46 AM, Darrick J. Wong wrote:
> On Mon, May 22, 2017 at 07:33:35PM -0500, Eric Sandeen wrote:
>> After the long discussion about warning the user and/or consumer
>> of xfs_metadumps about dirty logs, it crossed my mind that we
>> could use the reserved slot in the metadump header to tag the
>> file with attributes, so the consumer of the metadump knows how
>> it was created.
>>
>> This patch adds 3 flags to describe the metadump: dirty log,
>> obfuscated, and full blocks (unused portions of metadata blocks
>> are not zeroed out).
>>
>> It then adds a new option to xfs_mdrestore, "-i" to show info,
>> which can be used with or without a target file:
>> +/* mb_flags */
>> +#define XFS_METADUMP_OBFUSCATED (1 << 0)
>> +#define XFS_METADUMP_FULLBLOCKS (1 << 1)
>> +#define XFS_METADUMP_DIRTYLOG (1 << 2)
>
> If we always wrote zero for mb_reserved previously, how do we
> distinguish between a non-obfuscated partial-block clean-log metadump
> and an old metadump? Do we care?
Oh right. ;)
> I imagine metadumps are fairly transitory in nature, so it might not be
> a big deal, and probably not worth burning 1/8 of our flag-space over
> since AFAICT we don't use the(se) flags for any serious behavioral
> changes.
OTOH, how many flags would we possibly have? I'm ok with adding a
"we have flags" flag, too.
-Eric
> --D
>
>> +
>> #endif /* _XFS_METADUMP_H_ */
>> diff --git a/man/man8/xfs_mdrestore.8 b/man/man8/xfs_mdrestore.8
>> index 2095f15..10c00b2 100644
>> --- a/man/man8/xfs_mdrestore.8
>> +++ b/man/man8/xfs_mdrestore.8
>> @@ -4,11 +4,15 @@ xfs_mdrestore \- restores an XFS metadump image to a filesystem image
>> .SH SYNOPSIS
>> .B xfs_mdrestore
>> [
>> -.B \-g
>> +.B \-gi
>> ]
>> .I source
>> .I target
>> .br
>> +.B xfs_mdrestore
>> +.B \-i
>> +.I source
>> +.br
>> .B xfs_mdrestore \-V
>> .SH DESCRIPTION
>> .B xfs_mdrestore
>> @@ -39,6 +43,11 @@ can be destroyed.
>> .B \-g
>> Shows restore progress on stdout.
>> .TP
>> +.B \-i
>> +Shows metadump information on stdout. If no
>> +.I target
>> +is specified, exits after displaying information.
>> +.TP
>> .B \-V
>> Prints the version number and exits.
>> .SH DIAGNOSTICS
>> diff --git a/mdrestore/xfs_mdrestore.c b/mdrestore/xfs_mdrestore.c
>> index 0d399f1..1fbb1e6 100644
>> --- a/mdrestore/xfs_mdrestore.c
>> +++ b/mdrestore/xfs_mdrestore.c
>> @@ -21,6 +21,7 @@
>>
>> char *progname;
>> int show_progress = 0;
>> +int show_info = 0;
>> int progress_since_warning = 0;
>>
>> static void
>> @@ -213,11 +214,14 @@ main(
>>
>> progname = basename(argv[0]);
>>
>> - while ((c = getopt(argc, argv, "gV")) != EOF) {
>> + while ((c = getopt(argc, argv, "giV")) != EOF) {
>> switch (c) {
>> case 'g':
>> show_progress = 1;
>> break;
>> + case 'i':
>> + show_info = 1;
>> + break;
>> case 'V':
>> printf("%s version %s\n", progname, VERSION);
>> exit(0);
>> @@ -226,7 +230,11 @@ main(
>> }
>> }
>>
>> - if (argc - optind != 2)
>> + if (argc - optind < 1 || argc - optind > 2)
>> + usage();
>> +
>> + /* show_info without a target is ok */
>> + if (!show_info && argc - optind != 2)
>> usage();
>>
>> /* open source */
>> @@ -239,6 +247,29 @@ main(
>> if (src_f == NULL)
>> fatal("cannot open source dump file\n");
>> }
>> +
>> + if (show_info) {
>> + xfs_metablock_t mb;
>> +
>> + if (fread(&mb, sizeof(mb), 1, src_f) != 1)
>> + fatal("error reading from file: %s\n", strerror(errno));
>> +
>> + if (be32_to_cpu(mb.mb_magic) != XFS_MD_MAGIC)
>> + fatal("specified file is not a metadata dump\n");
>> +
>> + printf("%s: %sobfuscated, %s log, %s metadata blocks\n",
>> + argv[optind],
>> + mb.mb_flags & XFS_METADUMP_OBFUSCATED ? "" : "not ",
>> + mb.mb_flags & XFS_METADUMP_DIRTYLOG ? "dirty" : "clean",
>> + mb.mb_flags & XFS_METADUMP_FULLBLOCKS ? "full" : "zeroed");
>> +
>> + if (argc - optind == 1)
>> + exit(0);
>> +
>> + /* Go back to the beginning for the restore function */
>> + fseek(src_f, 0L, SEEK_SET);
>> + }
>> +
>> optind++;
>>
>> /* check and open target */
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
