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authorJens Axboe <axboe@kernel.dk>2024-09-11 22:54:32 +0300
committerJens Axboe <axboe@kernel.dk>2024-09-11 22:54:32 +0300
commitbfc0aa7a512f9a4462a88ca7352b00b83f8d68fd (patch)
tree24b4a25e54a354cdc67a9827f6c8e0d72534c08c /io_uring/rsrc.c
parent021b153f7d4115d99efa0d57ae2da6de1228295d (diff)
downloadlinux-bfc0aa7a512f9a4462a88ca7352b00b83f8d68fd.tar.xz
io_uring/rsrc: add reference count to struct io_mapped_ubuf
Currently there's a single ring owner of a mapped buffer, and hence the reference count will always be 1 when it's torn down and freed. However, in preparation for being able to link io_mapped_ubuf to different spots, add a reference count to manage the lifetime of it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/rsrc.c')
-rw-r--r--io_uring/rsrc.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index d42114845fac..28f98de3c304 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -116,6 +116,8 @@ static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slo
*slot = NULL;
if (imu != &dummy_ubuf) {
+ if (!refcount_dec_and_test(&imu->refs))
+ return;
for (i = 0; i < imu->nr_bvecs; i++)
unpin_user_page(imu->bvec[i].bv_page);
if (imu->acct_pages)
@@ -990,6 +992,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
imu->folio_shift = data.folio_shift;
imu->folio_mask = ~((1UL << data.folio_shift) - 1);
}
+ refcount_set(&imu->refs, 1);
off = (unsigned long) iov->iov_base & ~imu->folio_mask;
*pimu = imu;
ret = 0;