[PATCH v1] xfs_db: use preferable macro to seek offset for local dir3 entry fields

[PATCH v1] xfs_db: use preferable macro to seek offset for local dir3 entry fields

[Xiaole He]

In 'xfsprogs-dev' source:

/* db/dir2sf.c begin */
 #define        EOFF(f) bitize(offsetof(xfs_dir2_sf_entry_t, f))
const field_t   dir2_sf_entry_flds[] = {
        { "namelen", FLDT_UINT8D, OI(EOFF(namelen)), C1, 0, TYP_NONE },
...
 #define        E3OFF(f)        bitize(offsetof(xfs_dir2_sf_entry_t, f))
const field_t   dir3_sf_entry_flds[] = {
        { "namelen", FLDT_UINT8D, OI(EOFF(namelen)), C1, 0, TYP_NONE },
...
/* db/dir2sf.c end */

The macro definitions of 'EOFF' and 'E3OFF' are same, so no matter to
use either to seek field offset in 'dir3_sf_entry_flds'.
But it seems the intent of defining 'E3OFF' macro is to be used in
'dir3_sf_entry_flds', and 'E3OFF' macro has not been used at any place
of the 'xfsprogs-dev' source:

/* command begin */
$ grep -r E3OFF /path/to/xfsprogs-dev/git/repository/
./db/dir2sf.c:#define   E3OFF(f)        bitize(offsetof(xfs_dir2_sf_entry_t, f))
$
/* command end */

Above command shows the 'E3OFF' is only been defined but nerver been
used, that is weird, so there has reason to suspect using 'EOFF'
rather than 'E3OFF' in 'dir3_sf_entry_flds' is a typo, this patch fix
it, there has no logical change in this commit at all.

Signed-off-by: Xiaole He <hexiaole@kylinos.cn>
---
 db/dir2sf.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/db/dir2sf.c b/db/dir2sf.c
index 8165b79b..9f1880dc 100644
--- a/db/dir2sf.c
+++ b/db/dir2sf.c
@@ -246,9 +246,9 @@ const field_t	dir3sf_flds[] = {
 
 #define	E3OFF(f)	bitize(offsetof(xfs_dir2_sf_entry_t, f))
 const field_t	dir3_sf_entry_flds[] = {
-	{ "namelen", FLDT_UINT8D, OI(EOFF(namelen)), C1, 0, TYP_NONE },
-	{ "offset", FLDT_DIR2_SF_OFF, OI(EOFF(offset)), C1, 0, TYP_NONE },
-	{ "name", FLDT_CHARNS, OI(EOFF(name)), dir2_sf_entry_name_count,
+	{ "namelen", FLDT_UINT8D, OI(E3OFF(namelen)), C1, 0, TYP_NONE },
+	{ "offset", FLDT_DIR2_SF_OFF, OI(E3OFF(offset)), C1, 0, TYP_NONE },
+	{ "name", FLDT_CHARNS, OI(E3OFF(name)), dir2_sf_entry_name_count,
 	  FLD_COUNT, TYP_NONE },
 	{ "inumber", FLDT_DIR2_INOU, dir3_sf_entry_inumber_offset, C1,
 	  FLD_OFFSET, TYP_NONE },
-- 
2.27.0

Re: [PATCH v1] xfs_db: use preferable macro to seek offset for local dir3 entry fields

[Darrick J. Wong]

On Mon, Aug 29, 2022 at 05:50:25PM +0800, Xiaole He wrote:
> In 'xfsprogs-dev' source:
> 
> /* db/dir2sf.c begin */
>  #define        EOFF(f) bitize(offsetof(xfs_dir2_sf_entry_t, f))
> const field_t   dir2_sf_entry_flds[] = {
>         { "namelen", FLDT_UINT8D, OI(EOFF(namelen)), C1, 0, TYP_NONE },
> ...
>  #define        E3OFF(f)        bitize(offsetof(xfs_dir2_sf_entry_t, f))
> const field_t   dir3_sf_entry_flds[] = {
>         { "namelen", FLDT_UINT8D, OI(EOFF(namelen)), C1, 0, TYP_NONE },
> ...
> /* db/dir2sf.c end */
> 
> The macro definitions of 'EOFF' and 'E3OFF' are same, so no matter to
> use either to seek field offset in 'dir3_sf_entry_flds'.
> But it seems the intent of defining 'E3OFF' macro is to be used in
> 'dir3_sf_entry_flds', and 'E3OFF' macro has not been used at any place
> of the 'xfsprogs-dev' source:
> 
> /* command begin */
> $ grep -r E3OFF /path/to/xfsprogs-dev/git/repository/
> ./db/dir2sf.c:#define   E3OFF(f)        bitize(offsetof(xfs_dir2_sf_entry_t, f))
> $
> /* command end */
> 
> Above command shows the 'E3OFF' is only been defined but nerver been
> used, that is weird, so there has reason to suspect using 'EOFF'
> rather than 'E3OFF' in 'dir3_sf_entry_flds' is a typo, this patch fix
> it, there has no logical change in this commit at all.
> 
> Signed-off-by: Xiaole He <hexiaole@kylinos.cn>

Makes sense to me, though it took me a minute to learn to ignore the
other #define EOFFs :/

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  db/dir2sf.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/db/dir2sf.c b/db/dir2sf.c
> index 8165b79b..9f1880dc 100644
> --- a/db/dir2sf.c
> +++ b/db/dir2sf.c
> @@ -246,9 +246,9 @@ const field_t	dir3sf_flds[] = {
>  
>  #define	E3OFF(f)	bitize(offsetof(xfs_dir2_sf_entry_t, f))
>  const field_t	dir3_sf_entry_flds[] = {
> -	{ "namelen", FLDT_UINT8D, OI(EOFF(namelen)), C1, 0, TYP_NONE },
> -	{ "offset", FLDT_DIR2_SF_OFF, OI(EOFF(offset)), C1, 0, TYP_NONE },
> -	{ "name", FLDT_CHARNS, OI(EOFF(name)), dir2_sf_entry_name_count,
> +	{ "namelen", FLDT_UINT8D, OI(E3OFF(namelen)), C1, 0, TYP_NONE },
> +	{ "offset", FLDT_DIR2_SF_OFF, OI(E3OFF(offset)), C1, 0, TYP_NONE },
> +	{ "name", FLDT_CHARNS, OI(E3OFF(name)), dir2_sf_entry_name_count,
>  	  FLD_COUNT, TYP_NONE },
>  	{ "inumber", FLDT_DIR2_INOU, dir3_sf_entry_inumber_offset, C1,
>  	  FLD_OFFSET, TYP_NONE },
> -- 
> 2.27.0
>