diff options
| -rw-r--r-- | module/zfs/abd.c | 56 |
1 files changed, 55 insertions, 1 deletions
diff --git a/module/zfs/abd.c b/module/zfs/abd.c index 3d1ed63cf..6018a42ca 100644 --- a/module/zfs/abd.c +++ b/module/zfs/abd.c @@ -139,12 +139,15 @@ abd_verify(abd_t *abd) if (abd_is_linear(abd)) { ASSERT3P(ABD_LINEAR_BUF(abd), !=, NULL); } else if (abd_is_gang(abd)) { + uint_t child_sizes = 0; for (abd_t *cabd = list_head(&ABD_GANG(abd).abd_gang_chain); cabd != NULL; cabd = list_next(&ABD_GANG(abd).abd_gang_chain, cabd)) { ASSERT(list_link_active(&cabd->abd_gang_link)); + child_sizes += cabd->abd_size; abd_verify(cabd); } + ASSERT3U(abd->abd_size, ==, child_sizes); } else { abd_verify_scatter(abd); } @@ -378,16 +381,67 @@ abd_alloc_gang_abd(void) } /* + * Add a child gang ABD to a parent gang ABDs chained list. + */ +static void +abd_gang_add_gang(abd_t *pabd, abd_t *cabd, boolean_t free_on_free) +{ + ASSERT(abd_is_gang(pabd)); + ASSERT(abd_is_gang(cabd)); + + if (free_on_free) { + /* + * If the parent is responsible for freeing the child gang + * ABD we will just splice the childs children ABD list to + * the parents list and immediately free the child gang ABD + * struct. The parent gang ABDs children from the child gang + * will retain all the free_on_free settings after being + * added to the parents list. + */ + pabd->abd_size += cabd->abd_size; + list_move_tail(&ABD_GANG(pabd).abd_gang_chain, + &ABD_GANG(cabd).abd_gang_chain); + ASSERT(list_is_empty(&ABD_GANG(cabd).abd_gang_chain)); + abd_verify(pabd); + abd_free_struct(cabd); + } else { + for (abd_t *child = list_head(&ABD_GANG(cabd).abd_gang_chain); + child != NULL; + child = list_next(&ABD_GANG(cabd).abd_gang_chain, child)) { + /* + * We always pass B_FALSE for free_on_free as it is the + * original child gang ABDs responsibilty to determine + * if any of its child ABDs should be free'd on the call + * to abd_free(). + */ + abd_gang_add(pabd, child, B_FALSE); + } + abd_verify(pabd); + } +} + +/* * Add a child ABD to a gang ABD's chained list. */ void abd_gang_add(abd_t *pabd, abd_t *cabd, boolean_t free_on_free) { ASSERT(abd_is_gang(pabd)); - ASSERT(!abd_is_gang(cabd)); abd_t *child_abd = NULL; /* + * If the child being added is a gang ABD, we will add the + * childs ABDs to the parent gang ABD. This alllows us to account + * for the offset correctly in the parent gang ABD. + */ + if (abd_is_gang(cabd)) { + ASSERT(!list_link_active(&cabd->abd_gang_link)); + ASSERT(!list_is_empty(&ABD_GANG(cabd).abd_gang_chain)); + return (abd_gang_add_gang(pabd, cabd, free_on_free)); + } + ASSERT(!abd_is_gang(cabd)); + + /* * In order to verify that an ABD is not already part of * another gang ABD, we must lock the child ABD's abd_mtx * to check its abd_gang_link status. We unlock the abd_mtx |