From 0b3171b6d195637f84ddf8b59bae818ea20bc8ac Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 8 Jul 2020 17:35:16 +0200 Subject: ext4: do not block RWF_NOWAIT dio write on unallocated space Since commit 378f32bab371 ("ext4: introduce direct I/O write using iomap infrastructure") we don't properly bail out of RWF_NOWAIT direct IO write if underlying blocks are not allocated. Also ext4_dio_write_checks() does not honor RWF_NOWAIT when re-acquiring i_rwsem. Fix both issues. Fixes: 378f32bab371 ("ext4: introduce direct I/O write using iomap infrastructure") Cc: stable@kernel.org Reported-by: Filipe Manana Signed-off-by: Jan Kara Reviewed-by: Ritesh Harjani Link: https://lore.kernel.org/r/20200708153516.9507-1-jack@suse.cz Signed-off-by: Theodore Ts'o --- fs/ext4/file.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs') diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 453cafecf5cc..7a2720517bbb 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -427,6 +427,10 @@ restart: */ if (*ilock_shared && (!IS_NOSEC(inode) || *extend || !ext4_overwrite_io(inode, offset, count))) { + if (iocb->ki_flags & IOCB_NOWAIT) { + ret = -EAGAIN; + goto out; + } inode_unlock_shared(inode); *ilock_shared = false; inode_lock(inode); -- cgit v1.2.3