2023-11-30 13:54:06

by Ojaswin Mujoo

[permalink] [raw]
Subject: [RFC 1/7] iomap: Don't fall back to bufferred write if the write is atomic

Currently, iomap only supports atomic writes for direct IOs and there is
no guarantees that a bufferred IO will be atomic. Hence, if the user has
explicitly requested the direct write to be atomic and there's a
failure, return -EIO instead of falling back to bufferred IO.

Signed-off-by: Ojaswin Mujoo <[email protected]>
---
fs/iomap/direct-io.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 6ef25e26f1a1..d7e6c6eacbf7 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -662,7 +662,13 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
if (ret != -EAGAIN) {
trace_iomap_dio_invalidate_fail(inode, iomi.pos,
iomi.len);
- ret = -ENOTBLK;
+ /*
+ * if this write was supposed to be atomic,
+ * return the err rather than trying to fall
+ * back to bufferred IO.
+ */
+ if (!atomic_write)
+ ret = -ENOTBLK;
}
goto out_free_dio;
}
--
2.39.3