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io_uring: implement fixed buffers registration similar to fixed files

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Apply fixed_rsrc functionality for fixed buffers support.

Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
[rebase, remove multi-level tables, fix unregister on exit]
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/17035f4f75319dc92962fce4fc04bc0afb5a68dc.1619356238.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Bijan Mottahedeh 2021-04-25 14:32:25 +01:00 committed by Jens Axboe
parent eae071c9b4
commit bd54b6fe33
1 changed files with 56 additions and 15 deletions
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71
fs/io_uring.c
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@ -218,6 +218,7 @@ struct io_rsrc_put {
union {
void *rsrc;
struct file *file;
struct io_mapped_ubuf *buf;
};
};
@ -404,6 +405,7 @@ struct io_ring_ctx {
unsigned nr_user_files;
/* if used, fixed mapped user buffers */
struct io_rsrc_data *buf_data;
unsigned nr_user_bufs;
struct io_mapped_ubuf **user_bufs;
@ -5927,7 +5929,7 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
req->opcode);
return-EINVAL;
return -EINVAL;
}
static int io_req_prep_async(struct io_kiocb *req)
@ -8110,19 +8112,36 @@ static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slo
*slot = NULL;
}
static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
{
/* no updates yet, so not used */
WARN_ON_ONCE(1);
}
static void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
{
unsigned int i;
if (!ctx->user_bufs)
return -ENXIO;
for (i = 0; i < ctx->nr_user_bufs; i++)
io_buffer_unmap(ctx, &ctx->user_bufs[i]);
kfree(ctx->user_bufs);
kfree(ctx->buf_data);
ctx->user_bufs = NULL;
ctx->buf_data = NULL;
ctx->nr_user_bufs = 0;
return 0;
}
static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
{
int ret;
if (!ctx->buf_data)
return -ENXIO;
ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx);
if (!ret)
__io_sqe_buffers_unregister(ctx);
return ret;
}
static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
@ -8342,17 +8361,26 @@ static int io_buffer_validate(struct iovec *iov)
static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned int nr_args)
{
struct page *last_hpage = NULL;
struct io_rsrc_data *data;
int i, ret;
struct iovec iov;
struct page *last_hpage = NULL;
if (ctx->user_bufs)
return -EBUSY;
if (!nr_args || nr_args > UIO_MAXIOV)
return -EINVAL;
ret = io_buffers_map_alloc(ctx, nr_args);
ret = io_rsrc_node_switch_start(ctx);
if (ret)
return ret;
data = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, nr_args);
if (!data)
return -ENOMEM;
ret = io_buffers_map_alloc(ctx, nr_args);
if (ret) {
kfree(data);
return ret;
}
for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) {
ret = io_copy_iov(ctx, &iov, arg, i);
@ -8368,9 +8396,13 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
break;
}
if (ret)
io_sqe_buffers_unregister(ctx);
WARN_ON_ONCE(ctx->buf_data);
ctx->buf_data = data;
if (ret)
__io_sqe_buffers_unregister(ctx);
else
io_rsrc_node_switch(ctx, NULL);
return ret;
}
@ -8445,10 +8477,18 @@ static void io_req_caches_free(struct io_ring_ctx *ctx)
mutex_unlock(&ctx->uring_lock);
}
static bool io_wait_rsrc_data(struct io_rsrc_data *data)
{
if (!data)
return false;
if (!atomic_dec_and_test(&data->refs))
wait_for_completion(&data->done);
return true;
}
static void io_ring_ctx_free(struct io_ring_ctx *ctx)
{
io_sq_thread_finish(ctx);
io_sqe_buffers_unregister(ctx);
if (ctx->mm_account) {
mmdrop(ctx->mm_account);
@ -8456,11 +8496,10 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
}
mutex_lock(&ctx->uring_lock);
if (ctx->file_data) {
if (!atomic_dec_and_test(&ctx->file_data->refs))
wait_for_completion(&ctx->file_data->done);
if (io_wait_rsrc_data(ctx->buf_data))
__io_sqe_buffers_unregister(ctx);
if (io_wait_rsrc_data(ctx->file_data))
__io_sqe_files_unregister(ctx);
}
if (ctx->rings)
__io_cqring_overflow_flush(ctx, true);
mutex_unlock(&ctx->uring_lock);
@ -9825,6 +9864,8 @@ static int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
static bool io_register_op_must_quiesce(int op)
{
switch (op) {
case IORING_REGISTER_BUFFERS:
case IORING_UNREGISTER_BUFFERS:
case IORING_REGISTER_FILES:
case IORING_UNREGISTER_FILES:
case IORING_REGISTER_FILES_UPDATE: