This introduces the flag FMODE_BUF_WASYNC. If devices support async buffered writes, this flag can be set. It also modifies the check in generic_write_checks to take async buffered writes into consideration. Signed-off-by: Stefan Roesch <shr@xxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> --- fs/read_write.c | 4 +++- include/linux/fs.h | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/read_write.c b/fs/read_write.c index b1b1cdfee9d3..a1f4d45c2406 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1649,7 +1649,9 @@ 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))) return -EINVAL; return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count); diff --git a/include/linux/fs.h b/include/linux/fs.h index 9ad5e3520fae..bc84847c201e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -180,6 +180,9 @@ 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) + /* * Attribute flags. These should be or-ed together to figure out what * has been changed! -- 2.30.2
