linux/io_uring/rsrc.h
Jens Axboe b54a14041e io_uring/rsrc: add io_rsrc_node_lookup() helper
There are lots of spots open-coding this functionality, add a generic
helper that does the node lookup in a speculation safe way.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-02 15:45:30 -06:00

120 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifndef IOU_RSRC_H
#define IOU_RSRC_H
#define IO_NODE_ALLOC_CACHE_MAX 32
#define IO_RSRC_TAG_TABLE_SHIFT (PAGE_SHIFT - 3)
#define IO_RSRC_TAG_TABLE_MAX (1U << IO_RSRC_TAG_TABLE_SHIFT)
#define IO_RSRC_TAG_TABLE_MASK (IO_RSRC_TAG_TABLE_MAX - 1)
enum {
IORING_RSRC_FILE = 0,
IORING_RSRC_BUFFER = 1,
};
struct io_rsrc_node {
struct io_ring_ctx *ctx;
int refs;
u16 type;
u64 tag;
union {
unsigned long file_ptr;
struct io_mapped_ubuf *buf;
};
};
struct io_mapped_ubuf {
u64 ubuf;
unsigned int len;
unsigned int nr_bvecs;
unsigned int folio_shift;
refcount_t refs;
unsigned long acct_pages;
struct bio_vec bvec[] __counted_by(nr_bvecs);
};
struct io_imu_folio_data {
/* Head folio can be partially included in the fixed buf */
unsigned int nr_pages_head;
/* For non-head/tail folios, has to be fully included */
unsigned int nr_pages_mid;
unsigned int folio_shift;
};
struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx, int type);
void io_free_rsrc_node(struct io_rsrc_node *node);
void io_rsrc_data_free(struct io_rsrc_data *data);
int io_rsrc_data_alloc(struct io_rsrc_data *data, unsigned nr);
int io_import_fixed(int ddir, struct iov_iter *iter,
struct io_mapped_ubuf *imu,
u64 buf_addr, size_t len);
int io_register_clone_buffers(struct io_ring_ctx *ctx, void __user *arg);
int io_sqe_buffers_unregister(struct io_ring_ctx *ctx);
int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned int nr_args, u64 __user *tags);
int io_sqe_files_unregister(struct io_ring_ctx *ctx);
int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args, u64 __user *tags);
int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args);
int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
unsigned size, unsigned type);
int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
unsigned int size, unsigned int type);
extern const struct io_rsrc_node empty_node;
#define rsrc_empty_node (struct io_rsrc_node *) &empty_node
static inline struct io_rsrc_node *io_rsrc_node_lookup(struct io_rsrc_data *data,
int index)
{
if (index < data->nr)
return data->nodes[array_index_nospec(index, data->nr)];
return NULL;
}
static inline void io_put_rsrc_node(struct io_rsrc_node *node)
{
if (node != rsrc_empty_node && !--node->refs)
io_free_rsrc_node(node);
}
static inline void io_req_put_rsrc_nodes(struct io_kiocb *req)
{
if (req->rsrc_nodes[IORING_RSRC_FILE] != rsrc_empty_node) {
io_put_rsrc_node(req->rsrc_nodes[IORING_RSRC_FILE]);
req->rsrc_nodes[IORING_RSRC_FILE] = rsrc_empty_node;
}
if (req->rsrc_nodes[IORING_RSRC_BUFFER] != rsrc_empty_node) {
io_put_rsrc_node(req->rsrc_nodes[IORING_RSRC_BUFFER]);
req->rsrc_nodes[IORING_RSRC_BUFFER] = rsrc_empty_node;
}
}
static inline void io_req_assign_rsrc_node(struct io_kiocb *req,
struct io_rsrc_node *node)
{
if (node != rsrc_empty_node) {
node->refs++;
req->rsrc_nodes[node->type] = node;
}
}
int io_files_update(struct io_kiocb *req, unsigned int issue_flags);
int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int __io_account_mem(struct user_struct *user, unsigned long nr_pages);
static inline void __io_unaccount_mem(struct user_struct *user,
unsigned long nr_pages)
{
atomic_long_sub(nr_pages, &user->locked_vm);
}
#endif