From 91f9943e1c7b6638f27312d03fe71fcc67b23571 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 29 Aug 2017 16:13:20 +0200 Subject: fs: support RWF_NOWAIT for buffered reads This is based on the old idea and code from Milosz Tanski. With the aio nowait code it becomes mostly trivial now. Buffered writes continue to return -EOPNOTSUPP if RWF_NOWAIT is passed. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Al Viro --- fs/btrfs/file.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 9e75d8a39aac..e62dd55b4079 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1886,6 +1886,10 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, loff_t oldsize; int clean_page = 0; + if (!(iocb->ki_flags & IOCB_DIRECT) && + (iocb->ki_flags & IOCB_NOWAIT)) + return -EOPNOTSUPP; + if (!inode_trylock(inode)) { if (iocb->ki_flags & IOCB_NOWAIT) return -EAGAIN; @@ -3105,7 +3109,7 @@ out: static int btrfs_file_open(struct inode *inode, struct file *filp) { - filp->f_mode |= FMODE_AIO_NOWAIT; + filp->f_mode |= FMODE_NOWAIT; return generic_file_open(inode, filp); } -- cgit