ZAP: Fix leaf references on zap_expand_leaf() errors

Depending on kind of error zap_expand_leaf() may return with or
without valid leaf reference held.  Make sure it returns NULL if
due to error it has no leaf to return.  Make its callers to check
the returned leaf pointer, and release the leaf if it is not NULL.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #12366 
Closes #16159
This commit is contained in:
Alexander Motin 2024-05-10 15:35:20 -04:00 committed by Brian Behlendorf
parent 4c484d66b7
commit fa4b1a404e
1 changed files with 14 additions and 13 deletions

View File

@ -635,6 +635,7 @@ zap_expand_leaf(zap_name_t *zn, zap_leaf_t *l,
uint64_t object = zap->zap_object; uint64_t object = zap->zap_object;
zap_put_leaf(l); zap_put_leaf(l);
*lp = l = NULL;
zap_unlockdir(zap, tag); zap_unlockdir(zap, tag);
err = zap_lockdir(os, object, tx, RW_WRITER, err = zap_lockdir(os, object, tx, RW_WRITER,
FALSE, FALSE, tag, &zn->zn_zap); FALSE, FALSE, tag, &zn->zn_zap);
@ -844,21 +845,17 @@ retry:
} else if (err == EAGAIN) { } else if (err == EAGAIN) {
err = zap_expand_leaf(zn, l, tag, tx, &l); err = zap_expand_leaf(zn, l, tag, tx, &l);
zap = zn->zn_zap; /* zap_expand_leaf() may change zap */ zap = zn->zn_zap; /* zap_expand_leaf() may change zap */
if (err == 0) { if (err == 0)
goto retry; goto retry;
} else if (err == ENOSPC) {
/*
* If we failed to expand the leaf, then bailout
* as there is no point trying
* zap_put_leaf_maybe_grow_ptrtbl().
*/
return (err);
}
} }
out: out:
if (zap != NULL) if (l != NULL) {
zap_put_leaf_maybe_grow_ptrtbl(zn, l, tag, tx); if (err == ENOSPC)
zap_put_leaf(l);
else
zap_put_leaf_maybe_grow_ptrtbl(zn, l, tag, tx);
}
return (err); return (err);
} }
@ -915,8 +912,12 @@ retry:
goto retry; goto retry;
} }
if (zap != NULL) if (l != NULL) {
zap_put_leaf_maybe_grow_ptrtbl(zn, l, tag, tx); if (err == ENOSPC)
zap_put_leaf(l);
else
zap_put_leaf_maybe_grow_ptrtbl(zn, l, tag, tx);
}
return (err); return (err);
} }