Kernel allocated compound pages will have just one reference for the
entire page array, add a flag telling io_free_region about that.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
io_uring/memmap.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/io_uring/memmap.c b/io_uring/memmap.c
index 5d261e07c2e3..a37ccb167258 100644
--- a/io_uring/memmap.c
+++ b/io_uring/memmap.c
@@ -207,15 +207,23 @@ enum {
IO_REGION_F_VMAP = 1,
/* memory is provided by user and pinned by the kernel */
IO_REGION_F_USER_PROVIDED = 2,
+ /* only the first page in the array is ref'ed */
+ IO_REGION_F_SINGLE_REF = 4,
};
void io_free_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr)
{
if (mr->pages) {
+ long nr_refs = mr->nr_pages;
+
+ if (mr->flags & IO_REGION_F_SINGLE_REF)
+ nr_refs = 1;
+
if (mr->flags & IO_REGION_F_USER_PROVIDED)
- unpin_user_pages(mr->pages, mr->nr_pages);
+ unpin_user_pages(mr->pages, nr_refs);
else
- release_pages(mr->pages, mr->nr_pages);
+ release_pages(mr->pages, nr_refs);
+
kvfree(mr->pages);
}
if ((mr->flags & IO_REGION_F_VMAP) && mr->ptr)
--
2.47.1
