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authorJens Axboe <axboe@kernel.dk>2022-03-31 19:27:52 -0600
committerJens Axboe <axboe@kernel.dk>2022-05-09 06:35:33 -0600
commitebdeb7c01d025cb059f05dc26b9dc914e46dd43f (patch)
tree277d08ae7ef441660c3287eba92195b05becea9d /fs/io_uring.c
parentb5ba65df47cabcba6fe7a03f8f57513e9f78f72f (diff)
downloadlwn-ebdeb7c01d025cb059f05dc26b9dc914e46dd43f.tar.gz
lwn-ebdeb7c01d025cb059f05dc26b9dc914e46dd43f.zip
io_uring: add support for 128-byte SQEs
Normal SQEs are 64-bytes in length, which is fine for all the commands we support. However, in preparation for supporting passthrough IO, provide an option for setting up a ring with 128-byte SQEs. We continue to use the same type for io_uring_sqe, it's marked and commented with a zero sized array pad at the end. This provides up to 80 bytes of data for a passthrough command - 64 bytes for the extra added data, and 16 bytes available at the end of the existing SQE. Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
-rw-r--r--fs/io_uring.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 53e54fc05488..106a0db56ddb 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8519,8 +8519,12 @@ static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
* though the application is the one updating it.
*/
head = READ_ONCE(ctx->sq_array[sq_idx]);
- if (likely(head < ctx->sq_entries))
+ if (likely(head < ctx->sq_entries)) {
+ /* double index for 128-byte SQEs, twice as long */
+ if (ctx->flags & IORING_SETUP_SQE128)
+ head <<= 1;
return &ctx->sq_sqes[head];
+ }
/* drop invalid entries */
ctx->cq_extra--;
@@ -11689,7 +11693,10 @@ static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx,
rings->sq_ring_entries = p->sq_entries;
rings->cq_ring_entries = p->cq_entries;
- size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
+ if (p->flags & IORING_SETUP_SQE128)
+ size = array_size(2 * sizeof(struct io_uring_sqe), p->sq_entries);
+ else
+ size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
if (size == SIZE_MAX) {
io_mem_free(ctx->rings);
ctx->rings = NULL;
@@ -11933,7 +11940,8 @@ static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
IORING_SETUP_R_DISABLED | IORING_SETUP_SUBMIT_ALL |
- IORING_SETUP_COOP_TASKRUN | IORING_SETUP_TASKRUN_FLAG))
+ IORING_SETUP_COOP_TASKRUN | IORING_SETUP_TASKRUN_FLAG |
+ IORING_SETUP_SQE128))
return -EINVAL;
return io_uring_create(entries, &p, params);