| 1 | --- a/fs/Kconfig |
| 2 | +++ b/fs/Kconfig |
| 3 | @@ -62,6 +62,11 @@ config FILE_LOCKING |
| 4 | for filesystems like NFS and for the flock() system |
| 5 | call. Disabling this option saves about 11k. |
| 6 | |
| 7 | +config DIRECT_IO |
| 8 | + bool "Enable O_DIRECT support" if EXPERT |
| 9 | + depends on BLOCK |
| 10 | + default y |
| 11 | + |
| 12 | source "fs/notify/Kconfig" |
| 13 | |
| 14 | source "fs/quota/Kconfig" |
| 15 | --- a/fs/Makefile |
| 16 | +++ b/fs/Makefile |
| 17 | @@ -14,7 +14,8 @@ obj-y := open.o read_write.o file_table. |
| 18 | stack.o fs_struct.o statfs.o |
| 19 | |
| 20 | ifeq ($(CONFIG_BLOCK),y) |
| 21 | -obj-y += buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o |
| 22 | +obj-y += buffer.o bio.o block_dev.o mpage.o ioprio.o |
| 23 | +obj-$(CONFIG_DIRECT_IO) += direct-io.o |
| 24 | else |
| 25 | obj-y += no-block.o |
| 26 | endif |
| 27 | --- a/include/linux/fs.h |
| 28 | +++ b/include/linux/fs.h |
| 29 | @@ -2632,12 +2632,26 @@ enum { |
| 30 | DIO_SKIP_HOLES = 0x02, |
| 31 | }; |
| 32 | |
| 33 | +#ifdef CONFIG_DIRECT_IO |
| 34 | void dio_end_io(struct bio *bio, int error); |
| 35 | |
| 36 | ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, |
| 37 | struct block_device *bdev, const struct iovec *iov, loff_t offset, |
| 38 | unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io, |
| 39 | dio_submit_t submit_io, int flags); |
| 40 | +#else |
| 41 | +static inline void dio_end_io(struct bio *bio, int error) |
| 42 | +{ |
| 43 | +} |
| 44 | +static inline ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, |
| 45 | + struct block_device *bdev, const struct iovec *iov, loff_t offset, |
| 46 | + unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io, |
| 47 | + dio_submit_t submit_io, int flags) |
| 48 | +{ |
| 49 | + return -EOPNOTSUPP; |
| 50 | +} |
| 51 | +#endif |
| 52 | + |
| 53 | |
| 54 | static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb, |
| 55 | struct inode *inode, const struct iovec *iov, loff_t offset, |
| 56 | --- a/fs/fcntl.c |
| 57 | +++ b/fs/fcntl.c |
| 58 | @@ -169,8 +169,10 @@ static int setfl(int fd, struct file * f |
| 59 | arg |= O_NONBLOCK; |
| 60 | |
| 61 | if (arg & O_DIRECT) { |
| 62 | +#ifdef CONFIG_DIRECT_IO |
| 63 | if (!filp->f_mapping || !filp->f_mapping->a_ops || |
| 64 | !filp->f_mapping->a_ops->direct_IO) |
| 65 | +#endif |
| 66 | return -EINVAL; |
| 67 | } |
| 68 | |
| 69 | --- a/fs/open.c |
| 70 | +++ b/fs/open.c |
| 71 | @@ -636,9 +636,12 @@ int open_check_o_direct(struct file *f) |
| 72 | { |
| 73 | /* NB: we're sure to have correct a_ops only after f_op->open */ |
| 74 | if (f->f_flags & O_DIRECT) { |
| 75 | +#ifdef CONFIG_DIRECT_IO |
| 76 | if (!f->f_mapping->a_ops || |
| 77 | ((!f->f_mapping->a_ops->direct_IO) && |
| 78 | - (!f->f_mapping->a_ops->get_xip_mem))) { |
| 79 | + (!f->f_mapping->a_ops->get_xip_mem))) |
| 80 | +#endif |
| 81 | + { |
| 82 | return -EINVAL; |
| 83 | } |
| 84 | } |
| 85 | |
