io_uring: introduce ctx to tctx back map

For each pair tcxt-ctx create an object and chain it into ctx, so we
have a way to traverse all tctx that are using current ctx. Preparation
patch, will be used later.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-03-06 11:02:12 +00:00 committed by Jens Axboe
parent 2941267bd3
commit 13bf43f5f4

View File

@ -454,6 +454,7 @@ struct io_ring_ctx {
/* Keep this last, we don't need it for the fast path */
struct work_struct exit_work;
struct list_head tctx_list;
};
/*
@ -805,6 +806,13 @@ struct io_kiocb {
struct io_wq_work work;
};
struct io_tctx_node {
struct list_head ctx_node;
struct task_struct *task;
struct file *file;
struct io_ring_ctx *ctx;
};
struct io_defer_entry {
struct list_head list;
struct io_kiocb *req;
@ -1144,6 +1152,7 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
INIT_LIST_HEAD(&ctx->rsrc_ref_list);
INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work);
init_llist_head(&ctx->rsrc_put_llist);
INIT_LIST_HEAD(&ctx->tctx_list);
INIT_LIST_HEAD(&ctx->submit_state.comp.free_list);
INIT_LIST_HEAD(&ctx->submit_state.comp.locked_free_list);
return ctx;
@ -8748,6 +8757,7 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file)
{
struct io_uring_task *tctx = current->io_uring;
struct io_tctx_node *node;
int ret;
if (unlikely(!tctx)) {
@ -8760,13 +8770,25 @@ static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file)
void *old = xa_load(&tctx->xa, (unsigned long)file);
if (!old) {
node = kmalloc(sizeof(*node), GFP_KERNEL);
if (!node)
return -ENOMEM;
node->ctx = ctx;
node->file = file;
node->task = current;
get_file(file);
ret = xa_err(xa_store(&tctx->xa, (unsigned long)file,
file, GFP_KERNEL));
node, GFP_KERNEL));
if (ret) {
fput(file);
kfree(node);
return ret;
}
mutex_lock(&ctx->uring_lock);
list_add(&node->ctx_node, &ctx->tctx_list);
mutex_unlock(&ctx->uring_lock);
}
tctx->last = file;
}
@ -8788,23 +8810,31 @@ static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file)
static void io_uring_del_task_file(unsigned long index)
{
struct io_uring_task *tctx = current->io_uring;
struct file *file;
struct io_tctx_node *node;
file = xa_erase(&tctx->xa, index);
if (!file)
node = xa_erase(&tctx->xa, index);
if (!node)
return;
if (tctx->last == file)
WARN_ON_ONCE(current != node->task);
WARN_ON_ONCE(list_empty(&node->ctx_node));
mutex_lock(&node->ctx->uring_lock);
list_del(&node->ctx_node);
mutex_unlock(&node->ctx->uring_lock);
if (tctx->last == node->file)
tctx->last = NULL;
fput(file);
fput(node->file);
kfree(node);
}
static void io_uring_clean_tctx(struct io_uring_task *tctx)
{
struct file *file;
struct io_tctx_node *node;
unsigned long index;
xa_for_each(&tctx->xa, index, file)
xa_for_each(&tctx->xa, index, node)
io_uring_del_task_file(index);
if (tctx->io_wq) {
io_wq_put_and_exit(tctx->io_wq);
@ -8815,13 +8845,13 @@ static void io_uring_clean_tctx(struct io_uring_task *tctx)
void __io_uring_files_cancel(struct files_struct *files)
{
struct io_uring_task *tctx = current->io_uring;
struct file *file;
struct io_tctx_node *node;
unsigned long index;
/* make sure overflow events are dropped */
atomic_inc(&tctx->in_idle);
xa_for_each(&tctx->xa, index, file)
io_uring_cancel_task_requests(file->private_data, files);
xa_for_each(&tctx->xa, index, node)
io_uring_cancel_task_requests(node->ctx, files);
atomic_dec(&tctx->in_idle);
if (files)
@ -8884,11 +8914,11 @@ void __io_uring_task_cancel(void)
atomic_inc(&tctx->in_idle);
if (tctx->sqpoll) {
struct file *file;
struct io_tctx_node *node;
unsigned long index;
xa_for_each(&tctx->xa, index, file)
io_uring_cancel_sqpoll(file->private_data);
xa_for_each(&tctx->xa, index, node)
io_uring_cancel_sqpoll(node->ctx);
}
do {