From 43c696f9d094061e958e31be7f1dae66bc25d389 Mon Sep 17 00:00:00 2001 From: "Ritesh Harjani (IBM)" Date: Mon, 4 Nov 2024 16:22:58 -0800 Subject: [PATCH] ext4: Check for atomic writes support in write iter Let's validate the given constraints for atomic write request. Otherwise it will fail with -EINVAL. Currently atomic write is only supported on DIO, so for buffered-io it will return -EOPNOTSUPP. Reviewed-by: John Garry Reviewed-by: Darrick J. Wong Signed-off-by: Ritesh Harjani (IBM) Signed-off-by: Darrick J. Wong Reviewed-by: Jan Kara --- fs/ext4/file.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index f14aed14b9cf3..a7b9b9751a3f1 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -692,6 +692,20 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) if (IS_DAX(inode)) return ext4_dax_write_iter(iocb, from); #endif + + if (iocb->ki_flags & IOCB_ATOMIC) { + size_t len = iov_iter_count(from); + int ret; + + if (len < EXT4_SB(inode->i_sb)->s_awu_min || + len > EXT4_SB(inode->i_sb)->s_awu_max) + return -EINVAL; + + ret = generic_atomic_write_valid(iocb, from); + if (ret) + return ret; + } + if (iocb->ki_flags & IOCB_DIRECT) return ext4_dio_write_iter(iocb, from); else -- 2.39.5