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io_uring: track request creds with a flag

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Currently, if req->creds is not NULL, then there are creds assigned.
Track the invariant with a new flag in req->flags. No need to clear the
field at init, and also cleanup can be efficiently moved into
io_clean_op().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5f8baeb8d3b909487f555542350e2eac97005556.1623949695.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-06-17 18:14:02 +01:00 committed by Jens Axboe
parent c10d1f986b
commit b8e64b5300
1 changed files with 13 additions and 8 deletions
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21
fs/io_uring.c
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@ -718,6 +718,7 @@ enum {
REQ_F_COMPLETE_INLINE_BIT,
REQ_F_REISSUE_BIT,
REQ_F_DONT_REISSUE_BIT,
REQ_F_CREDS_BIT,
/* keep async read/write and isreg together and in order */
REQ_F_ASYNC_READ_BIT,
REQ_F_ASYNC_WRITE_BIT,
@ -771,6 +772,8 @@ enum {
REQ_F_ASYNC_WRITE = BIT(REQ_F_ASYNC_WRITE_BIT),
/* regular file */
REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
/* has creds assigned */
REQ_F_CREDS = BIT(REQ_F_CREDS_BIT),
};
struct async_poll {
@ -1236,8 +1239,10 @@ static void io_prep_async_work(struct io_kiocb *req)
const struct io_op_def *def = &io_op_defs[req->opcode];
struct io_ring_ctx *ctx = req->ctx;
if (!req->creds)
if (!(req->flags & REQ_F_CREDS)) {
req->flags |= REQ_F_CREDS;
req->creds = get_current_cred();
}
req->work.list.next = NULL;
req->work.flags = 0;
@ -1623,7 +1628,7 @@ static void io_req_complete_post(struct io_kiocb *req, long res,
static inline bool io_req_needs_clean(struct io_kiocb *req)
{
return req->flags & (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP |
REQ_F_POLLED | REQ_F_INFLIGHT);
REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS);
}
static void io_req_complete_state(struct io_kiocb *req, long res,
@ -1747,10 +1752,6 @@ static void io_dismantle_req(struct io_kiocb *req)
percpu_ref_put(req->fixed_rsrc_refs);
if (req->async_data)
kfree(req->async_data);
if (req->creds) {
put_cred(req->creds);
req->creds = NULL;
}
}
/* must to be called somewhat shortly after putting a request */
@ -6133,6 +6134,10 @@ static void io_clean_op(struct io_kiocb *req)
atomic_dec(&tctx->inflight_tracked);
req->flags &= ~REQ_F_INFLIGHT;
}
if (req->flags & REQ_F_CREDS) {
put_cred(req->creds);
req->flags &= ~REQ_F_CREDS;
}
}
static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
@ -6141,7 +6146,7 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
const struct cred *creds = NULL;
int ret;
if (req->creds && req->creds != current_cred())
if ((req->flags & REQ_F_CREDS) && req->creds != current_cred())
creds = override_creds(req->creds);
switch (req->opcode) {
@ -6534,7 +6539,6 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
atomic_set(&req->refs, 2);
req->task = current;
req->result = 0;
req->creds = NULL;
/* enforce forwards compatibility on users */
if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
@ -6556,6 +6560,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
if (!req->creds)
return -EINVAL;
get_cred(req->creds);
req->flags |= REQ_F_CREDS;
}
state = &ctx->submit_state;