io_uring/memmap: flag vmap'ed regions

Add internal flags for struct io_mapped_region. The first flag we need
is IO_REGION_F_VMAPPED, that indicates that the pointer has to be
unmapped on region destruction. For now all regions are vmap'ed, so it's
set unconditionally.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5a3d8046a038da97c0f8a8c8f1733fa3fc689d31.1732886067.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index fafc1d779eb14b2d04ae50f9ce5fb4fb6a229552..0793a91b66a5217fde1c91f99435ce057d8110d4 100644 (file)
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -78,8 +78,9 @@ struct io_hash_table {
 
 struct io_mapped_region {
        struct page             **pages;
-       void                    *vmap_ptr;
-       size_t                  nr_pages;
+       void                    *ptr;
+       unsigned                nr_pages;
+       unsigned                flags;
 };
 
 /*

diff --git a/io_uring/memmap.c b/io_uring/memmap.c
index a0d4151d11af3ebca5a014b3f51572825ae6dc17..31fb8c8ffe4eb1ebb2db658c8bdafb09f7d9f8b0 100644 (file)
--- a/io_uring/memmap.c
+++ b/io_uring/memmap.c
@@ -202,14 +202,19 @@ void *__io_uaddr_map(struct page ***pages, unsigned short *npages,
        return ERR_PTR(-ENOMEM);
 }
 
+enum {
+       /* memory was vmap'ed for the kernel, freeing the region vunmap's it */
+       IO_REGION_F_VMAP                        = 1,
+};
+
 void io_free_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr)
 {
        if (mr->pages) {
                unpin_user_pages(mr->pages, mr->nr_pages);
                kvfree(mr->pages);
        }
-       if (mr->vmap_ptr)
-               vunmap(mr->vmap_ptr);
+       if ((mr->flags & IO_REGION_F_VMAP) && mr->ptr)
+               vunmap(mr->ptr);
        if (mr->nr_pages && ctx->user)
                __io_unaccount_mem(ctx->user, mr->nr_pages);
 
@@ -225,7 +230,7 @@ int io_create_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr,
        void *vptr;
        u64 end;
 
-       if (WARN_ON_ONCE(mr->pages || mr->vmap_ptr || mr->nr_pages))
+       if (WARN_ON_ONCE(mr->pages || mr->ptr || mr->nr_pages))
                return -EFAULT;
        if (memchr_inv(&reg->__resv, 0, sizeof(reg->__resv)))
                return -EINVAL;
@@ -260,8 +265,9 @@ int io_create_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr,
        }
 
        mr->pages = pages;
-       mr->vmap_ptr = vptr;
+       mr->ptr = vptr;
        mr->nr_pages = nr_pages;
+       mr->flags |= IO_REGION_F_VMAP;
        return 0;
 out_free:
        if (pages_accounted)

diff --git a/io_uring/memmap.h b/io_uring/memmap.h
index f361a635b6c7574d0bb615bb80f76c6c297b9c5c..2096a8427277126dcbdc985be606646abef7346a 100644 (file)
--- a/io_uring/memmap.h
+++ b/io_uring/memmap.h
@@ -28,7 +28,7 @@ int io_create_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr,
 
 static inline void *io_region_get_ptr(struct io_mapped_region *mr)
 {
-       return mr->vmap_ptr;
+       return mr->ptr;
 }
 
 static inline bool io_region_is_set(struct io_mapped_region *mr)