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 <h...@lst.de> Reviewed-by: Jan Kara <j...@suse.cz> --- fs/aio.c | 6 ------ fs/btrfs/file.c | 6 +++++- fs/ext4/file.c | 6 +++--- fs/xfs/xfs_file.c | 11 +++++++++-- include/linux/fs.h | 6 +++--- 5 files changed, 20 insertions(+), 15 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index dcad3a66748c..d93daa076726 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1593,12 +1593,6 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, goto out_put_req; } - if ((req->common.ki_flags & IOCB_NOWAIT) && - !(req->common.ki_flags & IOCB_DIRECT)) { - ret = -EOPNOTSUPP; - goto out_put_req; - } - ret = put_user(KIOCB_KEY, &user_iocb->aio_key); if (unlikely(ret)) { pr_debug("EFAULT: aio_key\n"); 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 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence) 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); } diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 0d7cf0cc9b87..f83521337b8f 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -223,6 +223,8 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) if (IS_DAX(inode)) return ext4_dax_write_iter(iocb, from); #endif + if (!o_direct && (iocb->ki_flags & IOCB_NOWAIT)) + return -EOPNOTSUPP; if (!inode_trylock(inode)) { if (iocb->ki_flags & IOCB_NOWAIT) @@ -448,9 +450,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp) return ret; } - /* Set the flags to support nowait AIO */ - filp->f_mode |= FMODE_AIO_NOWAIT; - + filp->f_mode |= FMODE_NOWAIT; return dquot_file_open(inode, filp); } diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index c4893e226fd8..1a09104b3eb0 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -259,7 +259,11 @@ xfs_file_buffered_aio_read( trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos); - xfs_ilock(ip, XFS_IOLOCK_SHARED); + if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + xfs_ilock(ip, XFS_IOLOCK_SHARED); + } ret = generic_file_read_iter(iocb, to); xfs_iunlock(ip, XFS_IOLOCK_SHARED); @@ -636,6 +640,9 @@ xfs_file_buffered_aio_write( int enospc = 0; int iolock; + if (iocb->ki_flags & IOCB_NOWAIT) + return -EOPNOTSUPP; + write_retry: iolock = XFS_IOLOCK_EXCL; xfs_ilock(ip, iolock); @@ -912,7 +919,7 @@ xfs_file_open( return -EFBIG; if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb))) return -EIO; - file->f_mode |= FMODE_AIO_NOWAIT; + file->f_mode |= FMODE_NOWAIT; return 0; } diff --git a/include/linux/fs.h b/include/linux/fs.h index 6e1fd5d21248..ded258edc425 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -146,8 +146,8 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, /* File was opened by fanotify and shouldn't generate fanotify events */ #define FMODE_NONOTIFY ((__force fmode_t)0x4000000) -/* File is capable of returning -EAGAIN if AIO will block */ -#define FMODE_AIO_NOWAIT ((__force fmode_t)0x8000000) +/* File is capable of returning -EAGAIN if I/O will block */ +#define FMODE_NOWAIT ((__force fmode_t)0x8000000) /* * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector @@ -3149,7 +3149,7 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, int flags) return -EOPNOTSUPP; if (flags & RWF_NOWAIT) { - if (!(ki->ki_filp->f_mode & FMODE_AIO_NOWAIT)) + if (!(ki->ki_filp->f_mode & FMODE_NOWAIT)) return -EOPNOTSUPP; ki->ki_flags |= IOCB_NOWAIT; } -- 2.11.0