1 files changed, 80 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.3/903-debloat_direct_io.patch b/target/linux/generic/patches-4.3/903-debloat_direct_io.patch
new file mode 100644
index 0000000000..2ff3093fbe
--- /dev/null
+++ b/target/linux/generic/patches-4.3/903-debloat_direct_io.patch
@@ -0,0 +1,80 @@
+--- a/fs/Kconfig
++++ b/fs/Kconfig
+@@ -68,6 +68,11 @@ 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
+@@ -2695,6 +2695,7 @@ 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,
+@@ -2702,6 +2703,18 @@ 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;