2012-12-17 23:11:39 +08:00
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--- a/fs/Kconfig
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+++ b/fs/Kconfig
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@@ -62,6 +62,11 @@ 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
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ifeq ($(CONFIG_BLOCK),y)
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-obj-y += buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
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+obj-y += buffer.o bio.o block_dev.o mpage.o ioprio.o
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+obj-$(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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2012-12-18 04:55:49 +08:00
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@@ -2444,12 +2444,26 @@ enum {
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2012-12-17 23:11:39 +08:00
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DIO_SKIP_HOLES = 0x02,
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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(int rw, struct kiocb *iocb, struct inode *inode,
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struct block_device *bdev, const struct iovec *iov, loff_t offset,
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unsigned long nr_segs, 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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+#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(int rw, struct kiocb *iocb, struct inode *inode,
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+ struct block_device *bdev, const struct iovec *iov, loff_t offset,
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+ unsigned long nr_segs, 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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+
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static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
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struct inode *inode, const struct iovec *iov, loff_t offset,
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--- a/fs/fcntl.c
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+++ b/fs/fcntl.c
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@@ -51,8 +51,10 @@ 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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@@ -630,9 +630,12 @@ 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 ||
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((!f->f_mapping->a_ops->direct_IO) &&
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- (!f->f_mapping->a_ops->get_xip_mem))) {
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+ (!f->f_mapping->a_ops->get_xip_mem)))
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+#endif
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+ {
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return -EINVAL;
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}
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}
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