summaryrefslogtreecommitdiff
path: root/mm/swap_state.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/swap_state.c')
-rw-r--r--mm/swap_state.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c
index b13e9c4baa90..f4980dde5394 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -748,6 +748,8 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask,
blk_start_plug(&plug);
for (addr = start; addr < end; ilx++, addr += PAGE_SIZE) {
+ struct swap_info_struct *si = NULL;
+
if (!pte++) {
pte = pte_offset_map(vmf->pmd, addr);
if (!pte)
@@ -761,8 +763,19 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask,
continue;
pte_unmap(pte);
pte = NULL;
+ /*
+ * Readahead entry may come from a device that we are not
+ * holding a reference to, try to grab a reference, or skip.
+ */
+ if (swp_type(entry) != swp_type(targ_entry)) {
+ si = get_swap_device(entry);
+ if (!si)
+ continue;
+ }
folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx,
&page_allocated, false);
+ if (si)
+ put_swap_device(si);
if (!folio)
continue;
if (page_allocated) {