On Wed, Feb 01, 2023 at 06:21:47PM +0100, Andrey Albershteyn wrote:
> flist_find_ftyp() searches for the field of the requested type. The
> first found field/path is returned. However, this doesn't work when
> there are multiple fields of the same type. For example, attr3 type
> have a few CRC fields. Leaf block (xfs_attr_leaf_hdr ->
> xfs_da3_blkinfo) and remote value block (xfs_attr3_rmt_hdr) both
> have CRC but goes under attr3 type. This causes 'crc' command to be
> unable to find CRC field when we are at remote attribute block as it
> tries to use leaf block CRC path:
>
> $ dd if=/dev/zero bs=4k count=10 | tr '\000' '1' > test.img
> $ touch test.file
> $ setfattr -n user.bigattr -v "$(cat test.img)" test.file
>
> $ # CRC of the leaf block
> $ xfs_db -r -x /dev/sda5 -c 'inode 132' -c 'ablock 0' -c 'crc'
> Verifying CRC:
> hdr.info.crc = 0x102b5cbf (correct)
>
> $ # CRC of the remote value block
> $ xfs_db -r -x /dev/sda5 -c 'inode 132' -c 'ablock 1' -c 'crc'
> field info not found
> parsing error
>
> Solve this by making flist_find_ftyp() to also check that field in
> question have non-zero count (exist at the current block).
>
> Signed-off-by: Andrey Albershteyn <aalbersh@xxxxxxxxxx>
> ---
> db/crc.c | 2 +-
> db/flist.c | 13 ++++++++++---
> db/flist.h | 3 ++-
> 3 files changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/db/crc.c b/db/crc.c
> index 7428b916..1c73f980 100644
> --- a/db/crc.c
> +++ b/db/crc.c
> @@ -114,7 +114,7 @@ crc_f(
> }
>
> /* Search for a CRC field */
> - fl = flist_find_ftyp(fields, FLDT_CRC);
> + fl = flist_find_ftyp(fields, FLDT_CRC, iocur_top->data, 0);
> if (!fl) {
> dbprintf(_("No CRC field found for type %s\n"), cur_typ->name);
> return 0;
> diff --git a/db/flist.c b/db/flist.c
> index 0bb6474c..d275abfe 100644
> --- a/db/flist.c
> +++ b/db/flist.c
> @@ -408,11 +408,14 @@ flist_split(
> */
> flist_t *
> flist_find_ftyp(
> - const field_t *fields,
> - fldt_t type)
> + const field_t *fields,
> + fldt_t type,
> + void *obj,
> + int startoff)
> {
> flist_t *fl;
> const field_t *f;
> + int count;
> const ftattr_t *fa;
>
> for (f = fields; f->name; f++) {
> @@ -420,11 +423,15 @@ flist_find_ftyp(
> fl->fld = f;
> if (f->ftyp == type)
> return fl;
> + count = fcount(f, obj, startoff);
> + if (!count) {
> + continue;
> + }
Minor nit: no need for curly braces here.
With that cleaned up,
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> fa = &ftattrtab[f->ftyp];
> if (fa->subfld) {
> flist_t *nfl;
>
> - nfl = flist_find_ftyp(fa->subfld, type);
> + nfl = flist_find_ftyp(fa->subfld, type, obj, startoff);
> if (nfl) {
> fl->child = nfl;
> return fl;
> diff --git a/db/flist.h b/db/flist.h
> index f0772378..e327a360 100644
> --- a/db/flist.h
> +++ b/db/flist.h
> @@ -38,4 +38,5 @@ extern int flist_parse(const struct field *fields, flist_t *fl, void *obj,
> int startoff);
> extern void flist_print(flist_t *fl);
> extern flist_t *flist_scan(char *name);
> -extern flist_t *flist_find_ftyp(const field_t *fields, fldt_t type);
> +extern flist_t *flist_find_ftyp(const field_t *fields, fldt_t type, void *obj,
> + int startoff);
> --
> 2.31.1
>
