zonefs: fix IOCB_NOWAIT handling

IOCB_NOWAIT can't just be ignored as it breaks applications expecting
it not to block.  Just refuse the operation as applications must handle
that (e.g. by falling back to a thread pool).

Fixes: 8dcc1a9d90 ("fs: New zonefs file system")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
This commit is contained in:
Christoph Hellwig 2020-02-21 06:37:23 -08:00 committed by Damien Le Moal
parent 4c5fd3b791
commit 7c69eb84d9

View File

@ -601,13 +601,13 @@ static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
ssize_t ret;
/*
* For async direct IOs to sequential zone files, ignore IOCB_NOWAIT
* For async direct IOs to sequential zone files, refuse IOCB_NOWAIT
* as this can cause write reordering (e.g. the first aio gets EAGAIN
* on the inode lock but the second goes through but is now unaligned).
*/
if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && !is_sync_kiocb(iocb)
&& (iocb->ki_flags & IOCB_NOWAIT))
iocb->ki_flags &= ~IOCB_NOWAIT;
if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && !is_sync_kiocb(iocb) &&
(iocb->ki_flags & IOCB_NOWAIT))
return -EOPNOTSUPP;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!inode_trylock(inode))