On 5/19/22 1:17 AM, Christoph Hellwig wrote: > On Wed, May 18, 2022 at 04:36:52PM -0700, Stefan Roesch wrote: >> @@ -1633,7 +1633,9 @@ int generic_write_checks_count(struct kiocb *iocb, loff_t *count) >> if (iocb->ki_flags & IOCB_APPEND) >> iocb->ki_pos = i_size_read(inode); >> >> - if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) >> + if ((iocb->ki_flags & IOCB_NOWAIT) && >> + !((iocb->ki_flags & IOCB_DIRECT) || >> + (file->f_mode & FMODE_BUF_WASYNC))) > > This is some really odd indentation. I'd expect something like: > > if ((iocb->ki_flags & IOCB_NOWAIT) && > !((iocb->ki_flags & IOCB_DIRECT) || > (file->f_mode & FMODE_BUF_WASYNC))) > I reformatted the above code for the next version. >> diff --git a/include/linux/fs.h b/include/linux/fs.h >> index bbde95387a23..3b479d02e210 100644 >> --- a/include/linux/fs.h >> +++ b/include/linux/fs.h >> @@ -177,6 +177,9 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, >> /* File supports async buffered reads */ >> #define FMODE_BUF_RASYNC ((__force fmode_t)0x40000000) >> >> +/* File supports async nowait buffered writes */ >> +#define FMODE_BUF_WASYNC ((__force fmode_t)0x80000000) > > This is the last available flag in fmode_t. > > At some point we should probably move the static capabilities to > a member of file_operations.