1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/nospec.h>
#include <linux/io_uring.h>
#include <uapi/linux/io_uring.h>
#include "io_uring.h"
#include "rsrc.h"
#include "filetable.h"
static int io_file_bitmap_get(struct io_ring_ctx *ctx)
{
struct io_file_table *table = &ctx->file_table;
unsigned long nr = ctx->file_alloc_end;
int ret;
if (!table->bitmap)
return -ENFILE;
do {
ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint);
if (ret != nr)
return ret;
if (table->alloc_hint == ctx->file_alloc_start)
break;
nr = table->alloc_hint;
table->alloc_hint = ctx->file_alloc_start;
} while (1);
return -ENFILE;
}
bool io_alloc_file_tables(struct io_ring_ctx *ctx, struct io_file_table *table,
unsigned nr_files)
{
if (io_rsrc_data_alloc(&table->data, nr_files))
return false;
table->bitmap = bitmap_zalloc(nr_files, GFP_KERNEL_ACCOUNT);
if (table->bitmap)
return true;
io_rsrc_data_free(ctx, &table->data);
return false;
}
void io_free_file_tables(struct io_ring_ctx *ctx, struct io_file_table *table)
{
io_rsrc_data_free(ctx, &table->data);
bitmap_free(table->bitmap);
table->bitmap = NULL;
}
static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file,
u32 slot_index)
__must_hold(&req->ctx->uring_lock)
{
struct io_rsrc_node *node;
if (io_is_uring_fops(file))
return -EBADF;
if (!ctx->file_table.data.nr)
return -ENXIO;
if (slot_index >= ctx->file_table.data.nr)
return -EINVAL;
node = io_rsrc_node_alloc(ctx, IORING_RSRC_FILE);
if (!node)
return -ENOMEM;
if (!io_reset_rsrc_node(ctx, &ctx->file_table.data, slot_index))
io_file_bitmap_set(&ctx->file_table, slot_index);
ctx->file_table.data.nodes[slot_index] = node;
io_fixed_file_set(node, file);
return 0;
}
int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
unsigned int file_slot)
{
bool alloc_slot = file_slot == IORING_FILE_INDEX_ALLOC;
int ret;
if (alloc_slot) {
ret = io_file_bitmap_get(ctx);
if (unlikely(ret < 0))
return ret;
file_slot = ret;
} else {
file_slot--;
}
ret = io_install_fixed_file(ctx, file, file_slot);
if (!ret && alloc_slot)
ret = file_slot;
return ret;
}
/*
* Note when io_fixed_fd_install() returns error value, it will ensure
* fput() is called correspondingly.
*/
int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags,
struct file *file, unsigned int file_slot)
{
struct io_ring_ctx *ctx = req->ctx;
int ret;
io_ring_submit_lock(ctx, issue_flags);
ret = __io_fixed_fd_install(ctx, file, file_slot);
io_ring_submit_unlock(ctx, issue_flags);
if (unlikely(ret < 0))
fput(file);
return ret;
}
int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset)
{
struct io_rsrc_node *node;
if (unlikely(!ctx->file_table.data.nr))
return -ENXIO;
if (offset >= ctx->file_table.data.nr)
return -EINVAL;
node = io_rsrc_node_lookup(&ctx->file_table.data, offset);
if (!node)
return -EBADF;
io_reset_rsrc_node(ctx, &ctx->file_table.data, offset);
io_file_bitmap_clear(&ctx->file_table, offset);
return 0;
}
int io_register_file_alloc_range(struct io_ring_ctx *ctx,
struct io_uring_file_index_range __user *arg)
{
struct io_uring_file_index_range range;
u32 end;
if (copy_from_user(&range, arg, sizeof(range)))
return -EFAULT;
if (check_add_overflow(range.off, range.len, &end))
return -EOVERFLOW;
if (range.resv || end > ctx->file_table.data.nr)
return -EINVAL;
io_file_table_set_alloc_range(ctx, range.off, range.len);
return 0;
}
|
