forked from Minki/linux
6e73dffbb9
From recently io_uring provides an option to allocate a file index for operation registering fixed files. However, it's utterly unusable with mixed approaches when for a part of files the userspace knows better where to place it, as it may race and users don't have any sane way to pick a slot and hoping it will not be taken. Let the userspace to register a range of fixed file slots in which the auto-allocation happens. The use case is splittting the fixed table in two parts, where on of them is used for auto-allocation and another for slot-specified operations. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/66ab0394e436f38437cf7c44676e1920d09687ad.1656154403.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
89 lines
2.5 KiB
C
89 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#ifndef IOU_FILE_TABLE_H
|
|
#define IOU_FILE_TABLE_H
|
|
|
|
#include <linux/file.h>
|
|
#include <linux/io_uring_types.h>
|
|
|
|
/*
|
|
* FFS_SCM is only available on 64-bit archs, for 32-bit we just define it as 0
|
|
* and define IO_URING_SCM_ALL. For this case, we use SCM for all files as we
|
|
* can't safely always dereference the file when the task has exited and ring
|
|
* cleanup is done. If a file is tracked and part of SCM, then unix gc on
|
|
* process exit may reap it before __io_sqe_files_unregister() is run.
|
|
*/
|
|
#define FFS_NOWAIT 0x1UL
|
|
#define FFS_ISREG 0x2UL
|
|
#if defined(CONFIG_64BIT)
|
|
#define FFS_SCM 0x4UL
|
|
#else
|
|
#define IO_URING_SCM_ALL
|
|
#define FFS_SCM 0x0UL
|
|
#endif
|
|
#define FFS_MASK ~(FFS_NOWAIT|FFS_ISREG|FFS_SCM)
|
|
|
|
bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files);
|
|
void io_free_file_tables(struct io_file_table *table);
|
|
|
|
int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags,
|
|
struct file *file, unsigned int file_slot);
|
|
int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
|
|
unsigned int file_slot);
|
|
int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset);
|
|
|
|
int io_register_file_alloc_range(struct io_ring_ctx *ctx,
|
|
struct io_uring_file_index_range __user *arg);
|
|
|
|
unsigned int io_file_get_flags(struct file *file);
|
|
|
|
static inline void io_file_bitmap_clear(struct io_file_table *table, int bit)
|
|
{
|
|
__clear_bit(bit, table->bitmap);
|
|
table->alloc_hint = bit;
|
|
}
|
|
|
|
static inline void io_file_bitmap_set(struct io_file_table *table, int bit)
|
|
{
|
|
WARN_ON_ONCE(test_bit(bit, table->bitmap));
|
|
__set_bit(bit, table->bitmap);
|
|
table->alloc_hint = bit + 1;
|
|
}
|
|
|
|
static inline struct io_fixed_file *
|
|
io_fixed_file_slot(struct io_file_table *table, unsigned i)
|
|
{
|
|
return &table->files[i];
|
|
}
|
|
|
|
static inline struct file *io_file_from_index(struct io_file_table *table,
|
|
int index)
|
|
{
|
|
struct io_fixed_file *slot = io_fixed_file_slot(table, index);
|
|
|
|
return (struct file *) (slot->file_ptr & FFS_MASK);
|
|
}
|
|
|
|
static inline void io_fixed_file_set(struct io_fixed_file *file_slot,
|
|
struct file *file)
|
|
{
|
|
unsigned long file_ptr = (unsigned long) file;
|
|
|
|
file_ptr |= io_file_get_flags(file);
|
|
file_slot->file_ptr = file_ptr;
|
|
}
|
|
|
|
static inline void io_reset_alloc_hint(struct io_ring_ctx *ctx)
|
|
{
|
|
ctx->file_table.alloc_hint = ctx->file_alloc_start;
|
|
}
|
|
|
|
static inline void io_file_table_set_alloc_range(struct io_ring_ctx *ctx,
|
|
unsigned off, unsigned len)
|
|
{
|
|
ctx->file_alloc_start = off;
|
|
ctx->file_alloc_end = off + len;
|
|
io_reset_alloc_hint(ctx);
|
|
}
|
|
|
|
#endif
|