the-tree/io_uring/filetable.h

0001 // SPDX-License-Identifier: GPL-2.0
0002 #ifndef IOU_FILE_TABLE_H
0003 #define IOU_FILE_TABLE_H
0004
0005 #include <linux/file.h>
0006 #include <linux/io_uring_types.h>
0007
0008 /*
0009  * FFS_SCM is only available on 64-bit archs, for 32-bit we just define it as 0
0010  * and define IO_URING_SCM_ALL. For this case, we use SCM for all files as we
0011  * can't safely always dereference the file when the task has exited and ring
0012  * cleanup is done. If a file is tracked and part of SCM, then unix gc on
0013  * process exit may reap it before __io_sqe_files_unregister() is run.
0014  */
0015 #define FFS_NOWAIT      0x1UL
0016 #define FFS_ISREG       0x2UL
0017 #if defined(CONFIG_64BIT)
0018 #define FFS_SCM         0x4UL
0019 #else
0020 #define IO_URING_SCM_ALL
0021 #define FFS_SCM         0x0UL
0022 #endif
0023 #define FFS_MASK        ~(FFS_NOWAIT|FFS_ISREG|FFS_SCM)
0024
0025 bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files);
0026 void io_free_file_tables(struct io_file_table *table);
0027
0028 int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags,
0029             struct file *file, unsigned int file_slot);
0030 int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
0031                 unsigned int file_slot);
0032 int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset);
0033
0034 int io_register_file_alloc_range(struct io_ring_ctx *ctx,
0035                  struct io_uring_file_index_range __user *arg);
0036
0037 unsigned int io_file_get_flags(struct file *file);
0038
0039 static inline void io_file_bitmap_clear(struct io_file_table *table, int bit)
0040 {
0041     __clear_bit(bit, table->bitmap);
0042     table->alloc_hint = bit;
0043 }
0044
0045 static inline void io_file_bitmap_set(struct io_file_table *table, int bit)
0046 {
0047     WARN_ON_ONCE(test_bit(bit, table->bitmap));
0048     __set_bit(bit, table->bitmap);
0049     table->alloc_hint = bit + 1;
0050 }
0051
0052 static inline struct io_fixed_file *
0053 io_fixed_file_slot(struct io_file_table *table, unsigned i)
0054 {
0055     return &table->files[i];
0056 }
0057
0058 static inline struct file *io_file_from_index(struct io_file_table *table,
0059                           int index)
0060 {
0061     struct io_fixed_file *slot = io_fixed_file_slot(table, index);
0062
0063     return (struct file *) (slot->file_ptr & FFS_MASK);
0064 }
0065
0066 static inline void io_fixed_file_set(struct io_fixed_file *file_slot,
0067                      struct file *file)
0068 {
0069     unsigned long file_ptr = (unsigned long) file;
0070
0071     file_ptr |= io_file_get_flags(file);
0072     file_slot->file_ptr = file_ptr;
0073 }
0074
0075 static inline void io_reset_alloc_hint(struct io_ring_ctx *ctx)
0076 {
0077     ctx->file_table.alloc_hint = ctx->file_alloc_start;
0078 }
0079
0080 static inline void io_file_table_set_alloc_range(struct io_ring_ctx *ctx,
0081                          unsigned off, unsigned len)
0082 {
0083     ctx->file_alloc_start = off;
0084     ctx->file_alloc_end = off + len;
0085     io_reset_alloc_hint(ctx);
0086 }
0087
0088 #endif