1
0
Fork 0
mirror of synced 2025-03-06 20:59:54 +01:00
linux/io_uring/rw.h
Jens Axboe fa3595523d io_uring: get rid of alloc cache init_once handling
init_once is called when an object doesn't come from the cache, and
hence needs initial clearing of certain members. While the whole
struct could get cleared by memset() in that case, a few of the cache
members are large enough that this may cause unnecessary overhead if
the caches used aren't large enough to satisfy the workload. For those
cases, some churn of kmalloc+kfree is to be expected.

Ensure that the 3 users that need clearing put the members they need
cleared at the start of the struct, and wrap the rest of the struct in
a struct group so the offset is known.

While at it, improve the interaction with KASAN such that when/if
KASAN writes to members inside the struct that should be retained over
caching, it won't trip over itself. For rw and net, the retaining of
the iovec over caching is disabled if KASAN is enabled. A helper will
free and clear those members in that case.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-23 11:32:28 -07:00

45 lines
1.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/pagemap.h>
struct io_meta_state {
u32 seed;
struct iov_iter_state iter_meta;
};
struct io_async_rw {
size_t bytes_done;
struct iovec *free_iovec;
struct_group(clear,
struct iov_iter iter;
struct iov_iter_state iter_state;
struct iovec fast_iov;
int free_iov_nr;
/*
* wpq is for buffered io, while meta fields are used with
* direct io
*/
union {
struct wait_page_queue wpq;
struct {
struct uio_meta meta;
struct io_meta_state meta_state;
};
};
);
};
int io_prep_read_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_write_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_readv(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_writev(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_read(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_write(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_read(struct io_kiocb *req, unsigned int issue_flags);
int io_write(struct io_kiocb *req, unsigned int issue_flags);
void io_readv_writev_cleanup(struct io_kiocb *req);
void io_rw_fail(struct io_kiocb *req);
void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts);
int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags);
void io_rw_cache_free(const void *entry);