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io_uring: don't change sqpoll creds if not needed

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SQPOLL doesn't need to change creds if it's not submitting requests.
Move creds overriding into __io_sq_thread() after checking if there are
SQEs pending.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c54368da2357ac539e0a333f7cfff70d5fb045b2.1624543113.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-06-24 15:09:55 +01:00 committed by Jens Axboe
parent 4ce8ad95f0
commit 948e19479c
1 changed files with 7 additions and 7 deletions
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14
fs/io_uring.c
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@ -6803,6 +6803,10 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
if (!list_empty(&ctx->iopoll_list) || to_submit) {
unsigned nr_events = 0;
const struct cred *creds = NULL;
if (ctx->sq_creds != current_cred())
creds = override_creds(ctx->sq_creds);
mutex_lock(&ctx->uring_lock);
if (!list_empty(&ctx->iopoll_list))
@ -6819,6 +6823,8 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait))
wake_up(&ctx->sqo_sq_wait);
if (creds)
revert_creds(creds);
}
return ret;
@ -6870,7 +6876,6 @@ static int io_sq_thread(void *data)
mutex_lock(&sqd->lock);
while (1) {
int ret;
bool cap_entries, sqt_spin, needs_sched;
if (io_sqd_events_pending(sqd) || signal_pending(current)) {
@ -6883,13 +6888,8 @@ static int io_sq_thread(void *data)
sqt_spin = false;
cap_entries = !list_is_singular(&sqd->ctx_list);
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
const struct cred *creds = NULL;
int ret = __io_sq_thread(ctx, cap_entries);
if (ctx->sq_creds != current_cred())
creds = override_creds(ctx->sq_creds);
ret = __io_sq_thread(ctx, cap_entries);
if (creds)
revert_creds(creds);
if (!sqt_spin && (ret > 0 || !list_empty(&ctx->iopoll_list)))
sqt_spin = true;
}