diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 39883158b970..d8a4afc5eedb 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3528,35 +3528,31 @@ static ssize_t ext4_direct_IO_write(struct kiocb *iocb, struct iov_iter *iter) static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter) { - int unlocked = 0; - struct inode *inode = iocb->ki_filp->f_mapping->host; + struct address_space *mapping = iocb->ki_filp->f_mapping; + struct inode *inode = mapping->host; ssize_t ret; - if (ext4_should_dioread_nolock(inode)) { - /* - * Nolock dioread optimization may be dynamically disabled - * via ext4_inode_block_unlocked_dio(). Check inode's state - * while holding extra i_dio_count ref. - */ - inode_dio_begin(inode); - smp_mb(); - if (unlikely(ext4_test_inode_state(inode, - EXT4_STATE_DIOREAD_LOCK))) - inode_dio_end(inode); - else - unlocked = 1; - } + /* + * Shared inode_lock is enough for us - it protects against concurrent + * writes & truncates and since we take care of writing back page cache, + * we are protected against page writeback as well. + */ + inode_lock_shared(inode); if (IS_DAX(inode)) { - ret = dax_do_io(iocb, inode, iter, ext4_dio_get_block, - NULL, unlocked ? 0 : DIO_LOCKING); + ret = dax_do_io(iocb, inode, iter, ext4_dio_get_block, NULL, 0); } else { + size_t count = iov_iter_count(iter); + + ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, + iocb->ki_pos + count); + if (ret) + goto out_unlock; ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter, ext4_dio_get_block, - NULL, NULL, - unlocked ? 0 : DIO_LOCKING); + NULL, NULL, 0); } - if (unlocked) - inode_dio_end(inode); +out_unlock: + inode_unlock_shared(inode); return ret; }