Commit 9123c8ff authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: add helpers for 2 level table alloc 



Some parts like fixed file table use 2 level tables, factor out helpers
for allocating/deallocating them as more users are to come.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1709212359cd82eb416d395f86fc78431ccfc0aa.1623634181.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 157d257f

fs/io_uring.c

+43 −30
Original line number Diff line number Diff line
@@ -7059,14 +7059,36 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, 
	return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;

}



static void io_free_file_tables(struct io_file_table *table, unsigned nr_files)

static void io_free_page_table(void **table, size_t size)

{

	unsigned i, nr_tables = DIV_ROUND_UP(nr_files, IORING_MAX_FILES_TABLE);

	unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);



	for (i = 0; i < nr_tables; i++)

		kfree(table->files[i]);

	kfree(table->files);

	table->files = NULL;

		kfree(table[i]);

	kfree(table);

}



static void **io_alloc_page_table(size_t size)

{

	unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);

	size_t init_size = size;

	void **table;



	table = kcalloc(nr_tables, sizeof(*table), GFP_KERNEL);

	if (!table)

		return NULL;



	for (i = 0; i < nr_tables; i++) {

		unsigned int this_size = min(size, PAGE_SIZE);



		table[i] = kzalloc(this_size, GFP_KERNEL);

		if (!table[i]) {

			io_free_page_table(table, init_size);

			return NULL;

		}

		size -= this_size;

	}

	return table;

}



static inline void io_rsrc_ref_lock(struct io_ring_ctx *ctx)
@@ -7195,6 +7217,22 @@ static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, rsrc_put_fn *do_put, 
	return 0;

}



static bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files)

{

	size_t size = nr_files * sizeof(struct io_fixed_file);



	table->files = (struct io_fixed_file **)io_alloc_page_table(size);

	return !!table->files;

}



static void io_free_file_tables(struct io_file_table *table, unsigned nr_files)

{

	size_t size = nr_files * sizeof(struct io_fixed_file);



	io_free_page_table((void **)table->files, size);

	table->files = NULL;

}



static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)

{

#if defined(CONFIG_UNIX)
@@ -7456,31 +7494,6 @@ static int io_sqe_files_scm(struct io_ring_ctx *ctx) 
}

#endif



static bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files)

{

	unsigned i, nr_tables = DIV_ROUND_UP(nr_files, IORING_MAX_FILES_TABLE);



	table->files = kcalloc(nr_tables, sizeof(*table->files), GFP_KERNEL);

	if (!table->files)

		return false;



	for (i = 0; i < nr_tables; i++) {

		unsigned int this_files = min(nr_files, IORING_MAX_FILES_TABLE);



		table->files[i] = kcalloc(this_files, sizeof(*table->files[i]),

					GFP_KERNEL);

		if (!table->files[i])

			break;

		nr_files -= this_files;

	}



	if (i == nr_tables)

		return true;



	io_free_file_tables(table, nr_tables * IORING_MAX_FILES_TABLE);

	return false;

}



static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)

{

	struct file *file = prsrc->file;