xfs_db: make flist_find_ftyp() to check for field existance on disk

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@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

diff --git a/db/crc.c b/db/crc.c
index 7428b9160a2bc06390471382df6322b2debb5160..1c73f98036ff931921af8bde183b33e11084a5d7 100644 (file)
--- 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 0bb6474c3a771e1d489efca72dbdea0f006202a4..c81d229ab99c95cc801c792ac04c87c3576f3762 100644 (file)
--- 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 +423,14 @@ flist_find_ftyp(
                fl->fld = f;
                if (f->ftyp == type)
                        return fl;
+               count = fcount(f, obj, startoff);
+               if (!count)
+                       continue;
                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 f07723787d50d112479c014952bdffbb9461c547..e327a360422b9f65686e02396692ea40ce028dab 100644 (file)
--- 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);