kernel: remove out of tree direct-io disable hack

Direct-IO support has to be enabled for the release build anyway, so
this hack is not worth keeping

Signed-off-by: Felix Fietkau <nbd@nbd.name>
(backported from commit 0b7ed65cec)
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

config/Config-kernel.in

@@ -170,10 +170,6 @@ config KERNEL_AIO
 	bool "Compile the kernel with asynchronous IO support"
 	default n
 
-config KERNEL_DIRECT_IO
-	bool "Compile the kernel with direct IO support"
-	default n
-
 config KERNEL_FHANDLE
 	bool "Compile the kernel with support for fhandle syscalls"
 	default n

package/utils/mdadm/Makefile

@@ -27,7 +27,7 @@ define Package/mdadm
   SUBMENU:=Disc
   TITLE:=A tool for managing Soft RAID under Linux
   URL:=http://www.kernel.org/pub/linux/utils/raid/mdadm/
-  DEPENDS:=+@KERNEL_DIRECT_IO +libpthread +kmod-md-mod +kmod-md-raid0 +kmod-md-raid10 +kmod-md-raid1
+  DEPENDS:=+libpthread +kmod-md-mod +kmod-md-raid0 +kmod-md-raid10 +kmod-md-raid1
 endef
 
 define Package/mdadm/description

target/linux/generic/config-3.18

@@ -883,7 +883,6 @@ CONFIG_DEVPORT=y
 # CONFIG_DGNC is not set
 # CONFIG_DGRP is not set
 # CONFIG_DHT11 is not set
-# CONFIG_DIRECT_IO is not set
 CONFIG_DISABLE_DEV_COREDUMP=y
 # CONFIG_DISCONTIGMEM_MANUAL is not set
 # CONFIG_DISPLAY_CONNECTOR_ANALOG_TV is not set

target/linux/generic/config-4.4

@@ -916,7 +916,6 @@ CONFIG_DEVPORT=y
 # CONFIG_DGAP is not set
 # CONFIG_DGNC is not set
 # CONFIG_DHT11 is not set
-# CONFIG_DIRECT_IO is not set
 # CONFIG_DISCONTIGMEM_MANUAL is not set
 # CONFIG_DISPLAY_CONNECTOR_ANALOG_TV is not set
 # CONFIG_DISPLAY_CONNECTOR_DVI is not set

target/linux/generic/patches-3.18/903-debloat_direct_io.patch

@@ -1,83 +0,0 @@
---- a/fs/Kconfig
-+++ b/fs/Kconfig
-@@ -62,6 +62,11 @@ config FILE_LOCKING
-           for filesystems like NFS and for the flock() system
-           call. Disabling this option saves about 11k.
- 
-+config DIRECT_IO
-+	bool "Enable O_DIRECT support" if EXPERT
-+	depends on BLOCK
-+	default y
-+
- source "fs/notify/Kconfig"
- 
- source "fs/quota/Kconfig"
---- a/fs/Makefile
-+++ b/fs/Makefile
-@@ -14,7 +14,8 @@ obj-y :=	open.o read_write.o file_table.
- 		stack.o fs_struct.o statfs.o fs_pin.o
- 
- ifeq ($(CONFIG_BLOCK),y)
--obj-y +=	buffer.o block_dev.o direct-io.o mpage.o
-+obj-y +=	buffer.o block_dev.o mpage.o
-+obj-$(CONFIG_DIRECT_IO) += direct-io.o
- else
- obj-y +=	no-block.o
- endif
---- a/include/linux/fs.h
-+++ b/include/linux/fs.h
-@@ -2529,12 +2529,25 @@ enum {
- 	DIO_ASYNC_EXTEND = 0x04,
- };
- 
-+#ifdef CONFIG_DIRECT_IO
- void dio_end_io(struct bio *bio, int error);
- 
- ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
- 	struct block_device *bdev, struct iov_iter *iter, loff_t offset,
- 	get_block_t get_block, dio_iodone_t end_io,
- 	dio_submit_t submit_io,	int flags);
-+#else
-+static inline void dio_end_io(struct bio *bio, int error)
-+{
-+}
-+static inline ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
-+	struct block_device *bdev, struct iov_iter *iter, loff_t offset,
-+	get_block_t get_block, dio_iodone_t end_io,
-+	dio_submit_t submit_io,	int flags)
-+{
-+	return -EOPNOTSUPP;
-+}
-+#endif
- 
- static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
- 		struct inode *inode, struct iov_iter *iter, loff_t offset,
---- a/fs/fcntl.c
-+++ b/fs/fcntl.c
-@@ -52,8 +52,10 @@ static int setfl(int fd, struct file * f
- 		   arg |= O_NONBLOCK;
- 
- 	if (arg & O_DIRECT) {
-+#ifdef CONFIG_DIRECT_IO
- 		if (!filp->f_mapping || !filp->f_mapping->a_ops ||
- 			!filp->f_mapping->a_ops->direct_IO)
-+#endif
- 				return -EINVAL;
- 	}
- 
---- a/fs/open.c
-+++ b/fs/open.c
-@@ -655,9 +655,12 @@ int open_check_o_direct(struct file *f)
- {
- 	/* NB: we're sure to have correct a_ops only after f_op->open */
- 	if (f->f_flags & O_DIRECT) {
-+#ifdef CONFIG_DIRECT_IO
- 		if (!f->f_mapping->a_ops ||
- 		    ((!f->f_mapping->a_ops->direct_IO) &&
--		    (!f->f_mapping->a_ops->get_xip_mem))) {
-+		    (!f->f_mapping->a_ops->get_xip_mem)))
-+#endif
-+		{
- 			return -EINVAL;
- 		}
- 	}

target/linux/generic/patches-4.4/903-debloat_direct_io.patch

@@ -1,80 +0,0 @@
---- a/fs/Kconfig
-+++ b/fs/Kconfig
-@@ -74,6 +74,11 @@ config FILE_LOCKING
-           for filesystems like NFS and for the flock() system
-           call. Disabling this option saves about 11k.
- 
-+config DIRECT_IO
-+	bool "Enable O_DIRECT support" if EXPERT
-+	depends on BLOCK
-+	default y
-+
- source "fs/notify/Kconfig"
- 
- source "fs/quota/Kconfig"
---- a/fs/Makefile
-+++ b/fs/Makefile
-@@ -14,7 +14,8 @@ obj-y :=	open.o read_write.o file_table.
- 		stack.o fs_struct.o statfs.o fs_pin.o nsfs.o
- 
- ifeq ($(CONFIG_BLOCK),y)
--obj-y +=	buffer.o block_dev.o direct-io.o mpage.o
-+obj-y +=	buffer.o block_dev.o mpage.o
-+obj-$(CONFIG_DIRECT_IO) += direct-io.o
- else
- obj-y +=	no-block.o
- endif
---- a/include/linux/fs.h
-+++ b/include/linux/fs.h
-@@ -2722,6 +2722,7 @@ enum {
- 	DIO_SKIP_DIO_COUNT = 0x08,
- };
- 
-+#ifdef CONFIG_DIRECT_IO
- void dio_end_io(struct bio *bio, int error);
- 
- ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
-@@ -2729,6 +2730,18 @@ ssize_t __blockdev_direct_IO(struct kioc
- 			     loff_t offset, get_block_t get_block,
- 			     dio_iodone_t end_io, dio_submit_t submit_io,
- 			     int flags);
-+#else
-+static inline void dio_end_io(struct bio *bio, int error)
-+{
-+}
-+static inline ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
-+	struct block_device *bdev, struct iov_iter *iter, loff_t offset,
-+	get_block_t get_block, dio_iodone_t end_io,
-+	dio_submit_t submit_io,	int flags)
-+{
-+	return -EOPNOTSUPP;
-+}
-+#endif
- 
- static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
- 					 struct inode *inode,
---- a/fs/fcntl.c
-+++ b/fs/fcntl.c
-@@ -52,8 +52,10 @@ static int setfl(int fd, struct file * f
- 		   arg |= O_NONBLOCK;
- 
- 	if (arg & O_DIRECT) {
-+#ifdef CONFIG_DIRECT_IO
- 		if (!filp->f_mapping || !filp->f_mapping->a_ops ||
- 			!filp->f_mapping->a_ops->direct_IO)
-+#endif
- 				return -EINVAL;
- 	}
- 
---- a/fs/open.c
-+++ b/fs/open.c
-@@ -673,7 +673,9 @@ int open_check_o_direct(struct file *f)
- {
- 	/* NB: we're sure to have correct a_ops only after f_op->open */
- 	if (f->f_flags & O_DIRECT) {
-+#ifdef CONFIG_DIRECT_IO
- 		if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO)
-+#endif
- 			return -EINVAL;
- 	}
- 	return 0;

target/linux/oxnas/config-4.4

@@ -98,7 +98,6 @@ CONFIG_DEBUG_LL_INCLUDE="debug/icedcc.S"
 CONFIG_DEFAULT_HUNG_TASK_TIMEOUT=16
 CONFIG_DEPRECATED_PARAM_STRUCT=y
 CONFIG_DETECT_HUNG_TASK=y
-CONFIG_DIRECT_IO=y
 CONFIG_DMADEVICES=y
 CONFIG_DMA_CACHE_FIQ_BROADCAST=y
 # CONFIG_DMA_CACHE_RWFO is not set

target/linux/sunxi/config-4.4

@@ -136,7 +136,6 @@ CONFIG_DEBUG_MEMORY_INIT=y
 CONFIG_DEFAULT_CFQ=y
 # CONFIG_DEFAULT_DEADLINE is not set
 CONFIG_DEFAULT_IOSCHED="cfq"
-CONFIG_DIRECT_IO=y
 CONFIG_DMADEVICES=y
 CONFIG_DMA_ENGINE=y
 CONFIG_DMA_OF=y

target/linux/zynq/config-4.4

@@ -179,7 +179,6 @@ CONFIG_DEBUG_LL_INCLUDE="mach/debug-macro.S"
 CONFIG_DEFAULT_CFQ=y
 # CONFIG_DEFAULT_DEADLINE is not set
 CONFIG_DEFAULT_IOSCHED="cfq"
-CONFIG_DIRECT_IO=y
 CONFIG_DMADEVICES=y
 CONFIG_DMA_CMA=y
 CONFIG_DMA_ENGINE=y