1 files changed, 84 insertions, 0 deletions
diff --git a/target/linux/generic/patches-3.12/903-debloat_direct_io.patch b/target/linux/generic/patches-3.12/903-debloat_direct_io.patch
new file mode 100644
index 0000000..c2c7a43
--- /dev/null
+++ b/target/linux/generic/patches-3.12/903-debloat_direct_io.patch
@@ -0,0 +1,84 @@
+--- 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
+ 
+ ifeq ($(CONFIG_BLOCK),y)
+-obj-y +=	buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
++obj-y +=	buffer.o bio.o block_dev.o mpage.o ioprio.o
++obj-$(CONFIG_DIRECT_IO) += direct-io.o
+ else
+ obj-y +=	no-block.o
+ endif
+--- a/include/linux/fs.h
++++ b/include/linux/fs.h
+@@ -2487,12 +2487,26 @@ enum {
+ 	DIO_SKIP_HOLES	= 0x02,
+ };
+ 
++#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, const struct iovec *iov, loff_t offset,
+ 	unsigned long nr_segs, 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, const struct iovec *iov, loff_t offset,
++	unsigned long nr_segs, 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, const struct iovec *iov, loff_t offset,
+--- a/fs/fcntl.c
++++ b/fs/fcntl.c
+@@ -51,8 +51,10 @@ 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
+@@ -651,9 +651,12 @@ 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;
+ 		}
+ 	}