Re: [PATCH RFC v1 3/4] mke2fs: add options extended option for changing first inode

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Thu, Mar 12, 2015 at 07:20:15PM +0300, Konstantin Khlebnikov wrote:
> All currently reserved special inodes are assigned to some features. Some of
> them never been actually implemented so could be reused. But anyway there are
> only few special inodes left. Index of first normal inode is already stored in
> the super-block thus we can reserve more without changing disk layout.
> 
> This patch add extended option 'first_inode' for overriding default first inode
> (mostly for debug purpose). Features which want special inodes above 10 could
> change first_inode automatically.
> 
> Changing default first_inode is possible, but this breaks too much tests where
> inode numbers are present in expected output or even hardcoded: for example in
> "tst_inline_data".

Hmmm, that's going to make things interesting whenever we *do* need to
increase the default # of reserved inodes.

> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
> ---
>  misc/mke2fs.8.in |    8 ++++++++
>  misc/mke2fs.c    |   18 ++++++++++++++++++
>  2 files changed, 26 insertions(+)
> 
> diff --git a/misc/mke2fs.8.in b/misc/mke2fs.8.in
> index aeb5caf6e869..13f0c7a2c9d2 100644
> --- a/misc/mke2fs.8.in
> +++ b/misc/mke2fs.8.in
> @@ -369,6 +369,14 @@ as default.
>  .TP
>  .BI nodiscard
>  Do not attempt to discard blocks at mkfs time.
> +.TP
> +.BI first_inode= inode-number
> +This defines first normal inode, lower inodes are reserved for internal use.
> +For filesystem revision 0 this valus is fixed to 11, that is default and
> +minimal value for revision 1. This could be changed at a later time with the

I doubt there are very many people formatting a rev0 FS these days. :)

"valus" -> "value" above.

> +.B \-I
> +command-line option to
> +.BR resize2fs (8).
>  @QUOTA_MAN_COMMENT@.TP
>  @QUOTA_MAN_COMMENT@.BI quotatype
>  @QUOTA_MAN_COMMENT@Specify which quota type ('usr' or 'grp') is to be
> diff --git a/misc/mke2fs.c b/misc/mke2fs.c
> index ec450adf9e12..73d148206c69 100644
> --- a/misc/mke2fs.c
> +++ b/misc/mke2fs.c
> @@ -1005,6 +1005,23 @@ static void parse_extended_opts(struct ext2_super_block *param,
>  			discard = 1;
>  		} else if (!strcmp(token, "nodiscard")) {
>  			discard = 0;
> +		} else if (!strcmp(token, "first_inode")) {
> +			if (!arg) {
> +				r_usage++;
> +				badopt = token;
> +				continue;
> +			}
> +			param->s_first_ino = strtoul(arg, &p, 0);
> +			if (*p ||
> +			    param->s_first_ino < EXT2_GOOD_OLD_FIRST_INO ||
> +			    (param->s_rev_level == EXT2_GOOD_OLD_REV &&
> +			     param->s_first_ino != EXT2_GOOD_OLD_FIRST_INO)) {
> +				fprintf(stderr,
> +					_("Invalid first_ino parameter: %s\n"),

"Invalid first_inode parameter"; please keep the parameter name consistent in
the program output.

> +					arg);
> +				r_usage++;
> +				continue;
> +			}
>  		} else if (!strcmp(token, "quotatype")) {
>  			if (!arg) {
>  				r_usage++;
> @@ -1047,6 +1064,7 @@ static void parse_extended_opts(struct ext2_super_block *param,
>  			"\ttest_fs\n"
>  			"\tdiscard\n"
>  			"\tnodiscard\n"
> +			"\tfirst_inode=<inode number>\n"
>  			"\tquotatype=<usr OR grp>\n\n"),
>  			badopt ? badopt : "");
>  		free(buf);
> 
> --
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