Currently, an unaligned dio read at eof on ext4 returns EINVAL from
do_blockdev_direct_IO. However this unaligned dio read at eof could be due
to previous short read and we should return zero.
Fix this by checking for this condition in ext4_direct_IO_read()
and returning zero, if true.
Signed-off-by: Ashish Samant <[email protected]>
---
fs/ext4/inode.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 534a913..8b3dbc0 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3806,7 +3806,7 @@ static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter)
struct address_space *mapping = iocb->ki_filp->f_mapping;
struct inode *inode = mapping->host;
size_t count = iov_iter_count(iter);
- ssize_t ret;
+ ssize_t ret = 0;
/*
* Shared inode_lock is enough for us - it protects against concurrent
@@ -3814,6 +3814,8 @@ static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter)
* we are protected against page writeback as well.
*/
inode_lock_shared(inode);
+ if (iocb->ki_pos >= i_size_read(inode))
+ goto out_unlock;
ret = filemap_write_and_wait_range(mapping, iocb->ki_pos,
iocb->ki_pos + count - 1);
if (ret)
--
1.9.1