| Message ID | c32bee8a-f0aa-245-f94e-24dd271924fa@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [next] mm/shmem: fix shmem folio swapoff hang | expand |
On 2022/5/22 10:53, Hugh Dickins wrote: > Shmem swapoff makes no progress: the index to indices is not incremented. Yes, there would be a infinite loop in the while loop in shmem_unuse_inode(). > But "ret" is no longer a return value, so use folio_batch_count() instead. > > Fixes: da08e9b79323 ("mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio()") > Signed-off-by: Hugh Dickins <hughd@google.com> This patch looks good to me! Thanks! Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Miaohe Lin <linmiaohe@huawei.com> BTW: When I try to fix infinite loop when swap in shmem error at swapoff time, I also found this issue last Saturday [1]. ;) [1] https://lore.kernel.org/linux-mm/0f6dc98b-88f4-c0c9-eb7b-5356ad0e08b1@huawei.com/ > --- > > mm/shmem.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1171,7 +1171,6 @@ static int shmem_find_swap_entries(struc > XA_STATE(xas, &mapping->i_pages, start); > struct folio *folio; > swp_entry_t entry; > - unsigned int ret = 0; > > rcu_read_lock(); > xas_for_each(&xas, folio, ULONG_MAX) { > @@ -1189,7 +1188,7 @@ static int shmem_find_swap_entries(struc > if (swp_type(entry) != type) > continue; > > - indices[ret] = xas.xa_index; > + indices[folio_batch_count(fbatch)] = xas.xa_index; > if (!folio_batch_add(fbatch, folio)) > break; > > > . >
--- a/mm/shmem.c +++ b/mm/shmem.c @@ -1171,7 +1171,6 @@ static int shmem_find_swap_entries(struc XA_STATE(xas, &mapping->i_pages, start); struct folio *folio; swp_entry_t entry; - unsigned int ret = 0; rcu_read_lock(); xas_for_each(&xas, folio, ULONG_MAX) { @@ -1189,7 +1188,7 @@ static int shmem_find_swap_entries(struc if (swp_type(entry) != type) continue; - indices[ret] = xas.xa_index; + indices[folio_batch_count(fbatch)] = xas.xa_index; if (!folio_batch_add(fbatch, folio)) break;
Shmem swapoff makes no progress: the index to indices is not incremented. But "ret" is no longer a return value, so use folio_batch_count() instead. Fixes: da08e9b79323 ("mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio()") Signed-off-by: Hugh Dickins <hughd@google.com> --- mm/shmem.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)