generic: early (incomplete!) 4.0 support

[openwrt/openwrt.git] / target / linux / generic / patches-4.0 / 903-debloat_direct_io.patch

diff --git a/target/linux/generic/patches-4.0/903-debloat_direct_io.patch b/target/linux/generic/patches-4.0/903-debloat_direct_io.patch
new file mode 100644 (file)
index 0000000..cb32df2
--- /dev/null
+++ b/target/linux/generic/patches-4.0/903-debloat_direct_io.patch
@@ -0,0 +1,79 @@
+--- a/fs/Kconfig
++++ b/fs/Kconfig
+@@ -70,6 +70,11 @@ 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
+@@ -2614,12 +2614,25 @@ 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
+@@ -667,7 +667,9 @@ 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;