[Cluster-devel] [gfs2-utils patch] gfs2_edit: Print block types with log descriptors

[Andrew Price <anprice@redhat.com>]

On 11/06/14 18:35, Bob Peterson wrote:
> Hi,
>
> This patch makes gfs2_edit's journal print function print the metadata
> block type along side the block number in its log descriptor output.
> For example: In the past, when a log descriptor was printed, it looked
> like this:
> 0x8200 (j+ 163): Log descriptor, type 300 (Metadata) len:504, data1: 503 (503)
>                      0x70eb772          0x70df987          0x70dc7a1          0x70eb574
>                      0x70dc5a3          0x70eb376          0x70dc3a5          0x70eb178
>                      0x70dc1a7          0x70eaf7a          0x70dbfa9          0x70ead7c
> With this patch, the output is more useful:
> 0x8200 (j+ 163): Log descriptor, type 300 (Metadata) len:504, data1: 503 (503)
>                      0x70eb772 in       0x70df987 rb       0x70dc7a1 in       0x70eb574 in
>                      0x70dc5a3 in       0x70eb376 in       0x70dc3a5 in       0x70eb178 in
>                      0x70dc1a7 in       0x70eaf7a in       0x70dbfa9 in       0x70ead7c in
> In this case, "in" indicates indirect blocks, and "rb" indicates a rgrp bitmap.
> This is useful for getting a bigger picture of what that journal descriptor
> contains and represents.

These look good to me - thanks.

Aside: There's a whole lot of nesting and line splitting going on in 
this part of the code, and it's not the only place, so I'd like us all 
to start identifying bits like that and refactoring them as we go along, 
so that they become a little easier to work with and reason about. Just 
something to keep in mind for future work - I don't want to hold up 
these improvements.

Cheers,
Andy

> Regards,
>
> Bob Peterson
> Red Hat File Systems
>
> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
> ---
> diff --git a/gfs2/edit/hexedit.h b/gfs2/edit/hexedit.h
> index 541684a..f23c581 100644
> --- a/gfs2/edit/hexedit.h
> +++ b/gfs2/edit/hexedit.h
> @@ -27,6 +27,7 @@ enum dsp_mode { HEX_MODE = 0, GFS2_MODE = 1, EXTENDED_MODE = 2, INIT_MODE = 3 };
>   #define RGLIST_DUMMY_BLOCK -2
>   #define JOURNALS_DUMMY_BLOCK -3
>
> +extern const char *mtypes[];
>   extern struct gfs2_sb sb;
>   extern uint64_t block;
>   extern int blockhist;
> diff --git a/gfs2/edit/journal.c b/gfs2/edit/journal.c
> index bb56649..a72a044 100644
> --- a/gfs2/edit/journal.c
> +++ b/gfs2/edit/journal.c
> @@ -202,6 +202,7 @@ static int print_ld_blks(const uint64_t *b, const char *end, int start_line,
>   {
>   	int bcount = 0, found_tblk = 0, found_bblk = 0;
>   	static char str[256];
> +	struct gfs2_buffer_head *j_bmap_bh;
>
>   	if (tblk_off)
>   		*tblk_off = 0;
> @@ -218,8 +219,17 @@ static int print_ld_blks(const uint64_t *b, const char *end, int start_line,
>   			}
>   			bcount++;
>   			if (prnt) {
> -				sprintf(str, "0x%llx",
> -					(unsigned long long)be64_to_cpu(*b));
> +				if (is_meta_ld) {
> +					j_bmap_bh = bread(&sbd, abs_block +
> +							  bcount);
> +					sprintf(str, "0x%llx %2s",
> +						(unsigned long long)be64_to_cpu(*b),
> +						mtypes[lgfs2_get_block_type(j_bmap_bh)]);
> +					brelse(j_bmap_bh);
> +				} else {
> +					sprintf(str, "0x%llx",
> +						(unsigned long long)be64_to_cpu(*b));
> +				}
>   				print_gfs2("%-18.18s ", str);
>   			}
>   			if (!found_tblk && tblk_off)
> @@ -237,7 +247,6 @@ static int print_ld_blks(const uint64_t *b, const char *end, int start_line,
>   				int type, bmap = 0;
>   				uint64_t o;
>   				struct gfs2_buffer_head *save_bh;
> -				struct gfs2_buffer_head *j_bmap_bh;
>
>   				found_bblk = 1;
>   				print_gfs2("<-------------------------");
>