io_uring: separate out file table handling code

Signed-off-by: Jens Axboe <[email protected]>
kawasaki · Jul 25, 2022 · 453b329 · 453b329
1 parent f4c163d
commit 453b329
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Showing 5 changed files with 117 additions and 93 deletions.
diff --git a/io_uring/Makefile b/io_uring/Makefile
@@ -3,5 +3,5 @@
 # Makefile for io_uring
 
 obj-$(CONFIG_IO_URING)		+= io_uring.o xattr.o nop.o fs.o splice.o \
-					sync.o advise.o
+					sync.o advise.o filetable.o
 obj-$(CONFIG_IO_WQ)		+= io-wq.o
diff --git a/io_uring/filetable.c b/io_uring/filetable.c
@@ -0,0 +1,57 @@
+// 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/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "io_uring_types.h"
+#include "io_uring.h"
+
+int io_file_bitmap_get(struct io_ring_ctx *ctx)
+{
+	struct io_file_table *table = &ctx->file_table;
+	unsigned long nr = ctx->nr_user_files;
+	int ret;
+
+	do {
+		ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint);
+		if (ret != nr)
+			return ret;
+
+		if (!table->alloc_hint)
+			break;
+
+		nr = table->alloc_hint;
+		table->alloc_hint = 0;
+	} while (1);
+
+	return -ENFILE;
+}
+
+bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files)
+{
+	table->files = kvcalloc(nr_files, sizeof(table->files[0]),
+				GFP_KERNEL_ACCOUNT);
+	if (unlikely(!table->files))
+		return false;
+
+	table->bitmap = bitmap_zalloc(nr_files, GFP_KERNEL_ACCOUNT);
+	if (unlikely(!table->bitmap)) {
+		kvfree(table->files);
+		return false;
+	}
+
+	return true;
+}
+
+void io_free_file_tables(struct io_file_table *table)
+{
+	kvfree(table->files);
+	bitmap_free(table->bitmap);
+	table->files = NULL;
+	table->bitmap = NULL;
+}
diff --git a/io_uring/filetable.h b/io_uring/filetable.h
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef IOU_FILE_TABLE_H
+#define IOU_FILE_TABLE_H
+
+struct io_ring_ctx;
+
+/*
+ * 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)
+
+struct io_fixed_file {
+	/* file * with additional FFS_* flags */
+	unsigned long file_ptr;
+};
+
+struct io_file_table {
+	struct io_fixed_file *files;
+	unsigned long *bitmap;
+	unsigned int alloc_hint;
+};
+
+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_file_bitmap_get(struct io_ring_ctx *ctx);
+
+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];
+}
+
+#endif
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
@@ -146,28 +146,6 @@ struct io_overflow_cqe {
 	struct io_uring_cqe cqe;
 };
 
-/*
- * 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)
-
-struct io_fixed_file {
-	/* file * with additional FFS_* flags */
-	unsigned long file_ptr;
-};
-
 struct io_rsrc_put {
 	struct list_head list;
 	u64 tag;
@@ -3983,27 +3961,6 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	return __io_openat_prep(req, sqe);
 }
 
-static int io_file_bitmap_get(struct io_ring_ctx *ctx)
-{
-	struct io_file_table *table = &ctx->file_table;
-	unsigned long nr = ctx->nr_user_files;
-	int ret;
-
-	do {
-		ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint);
-		if (ret != nr)
-			return ret;
-
-		if (!table->alloc_hint)
-			break;
-
-		nr = table->alloc_hint;
-		table->alloc_hint = 0;
-	} while (1);
-
-	return -ENFILE;
-}
-
 /*
  * Note when io_fixed_fd_install() returns error value, it will ensure
  * fput() is called correspondingly.
@@ -6832,12 +6789,6 @@ static void io_wq_submit_work(struct io_wq_work *work)
 		io_req_task_queue_fail(req, ret);
 }
 
-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_ring_ctx *ctx,
 					      int index)
 {
@@ -7934,43 +7885,6 @@ static __cold int io_rsrc_data_alloc(struct io_ring_ctx *ctx, rsrc_put_fn *do_pu
 	return ret;
 }
 
-static bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files)
-{
-	table->files = kvcalloc(nr_files, sizeof(table->files[0]),
-				GFP_KERNEL_ACCOUNT);
-	if (unlikely(!table->files))
-		return false;
-
-	table->bitmap = bitmap_zalloc(nr_files, GFP_KERNEL_ACCOUNT);
-	if (unlikely(!table->bitmap)) {
-		kvfree(table->files);
-		return false;
-	}
-
-	return true;
-}
-
-static void io_free_file_tables(struct io_file_table *table)
-{
-	kvfree(table->files);
-	bitmap_free(table->bitmap);
-	table->files = NULL;
-	table->bitmap = NULL;
-}
-
-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 void io_file_bitmap_clear(struct io_file_table *table, int bit)
-{
-	__clear_bit(bit, table->bitmap);
-	table->alloc_hint = bit;
-}
-
 static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 {
 #if !defined(IO_URING_SCM_ALL)

diff --git a/io_uring/io_uring_types.h b/io_uring/io_uring_types.h
@@ -5,6 +5,7 @@
 #include <linux/task_work.h>
 
 #include "io-wq.h"
+#include "filetable.h"
 
 struct io_uring {
 	u32 head ____cacheline_aligned_in_smp;
@@ -122,12 +123,6 @@ struct io_ev_fd {
 	struct rcu_head		rcu;
 };
 
-struct io_file_table {
-	struct io_fixed_file *files;
-	unsigned long *bitmap;
-	unsigned int alloc_hint;
-};
-
 struct io_ring_ctx {
 	/* const or read-mostly hot data */
 	struct {