2015-06-22 12:27:59 +00:00
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--- a/fs/Kconfig
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+++ b/fs/Kconfig
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@@ -71,6 +71,11 @@ config FILE_LOCKING
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for filesystems like NFS and for the flock() system
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call. Disabling this option saves about 11k.
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+config DIRECT_IO
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+ bool "Enable O_DIRECT support" if EXPERT
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+ depends on BLOCK
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+ default y
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+
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source "fs/notify/Kconfig"
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source "fs/quota/Kconfig"
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--- a/fs/Makefile
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+++ b/fs/Makefile
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@@ -14,7 +14,8 @@ obj-y := open.o read_write.o file_table.
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stack.o fs_struct.o statfs.o fs_pin.o nsfs.o
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ifeq ($(CONFIG_BLOCK),y)
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-obj-y += buffer.o block_dev.o direct-io.o mpage.o
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+obj-y += buffer.o block_dev.o mpage.o
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+obj-$(CONFIG_DIRECT_IO) += direct-io.o
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else
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obj-y += no-block.o
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endif
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--- a/include/linux/fs.h
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+++ b/include/linux/fs.h
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2015-10-25 17:32:01 +00:00
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@@ -2647,6 +2647,7 @@ enum {
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2015-06-22 12:27:59 +00:00
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DIO_SKIP_DIO_COUNT = 0x08,
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};
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+#ifdef CONFIG_DIRECT_IO
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void dio_end_io(struct bio *bio, int error);
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ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
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2015-10-25 17:32:01 +00:00
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@@ -2654,6 +2655,18 @@ ssize_t __blockdev_direct_IO(struct kioc
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2015-06-22 12:27:59 +00:00
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loff_t offset, get_block_t get_block,
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dio_iodone_t end_io, dio_submit_t submit_io,
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int flags);
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+#else
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+static inline void dio_end_io(struct bio *bio, int error)
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+{
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+}
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+static inline ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
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+ struct block_device *bdev, struct iov_iter *iter, loff_t offset,
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+ get_block_t get_block, dio_iodone_t end_io,
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+ dio_submit_t submit_io, int flags)
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+{
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+ return -EOPNOTSUPP;
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+}
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+#endif
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static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
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struct inode *inode,
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--- a/fs/fcntl.c
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+++ b/fs/fcntl.c
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@@ -52,8 +52,10 @@ static int setfl(int fd, struct file * f
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arg |= O_NONBLOCK;
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if (arg & O_DIRECT) {
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+#ifdef CONFIG_DIRECT_IO
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if (!filp->f_mapping || !filp->f_mapping->a_ops ||
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!filp->f_mapping->a_ops->direct_IO)
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+#endif
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return -EINVAL;
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}
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--- a/fs/open.c
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+++ b/fs/open.c
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@@ -671,7 +671,9 @@ int open_check_o_direct(struct file *f)
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{
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/* NB: we're sure to have correct a_ops only after f_op->open */
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if (f->f_flags & O_DIRECT) {
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+#ifdef CONFIG_DIRECT_IO
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if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO)
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+#endif
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return -EINVAL;
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}
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return 0;
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