On 13/12/2023 13:31, Al Viro wrote:
Add file mode flag FMODE_CAN_ATOMIC_WRITE, so files which do not have the
flag set will have RWF_ATOMIC rejected and not just ignored.
Signed-off-by: Prasad Singamsetty<prasad.singamsetty@xxxxxxxxxx>
Signed-off-by: John Garry<john.g.garry@xxxxxxxxxx>
---
include/linux/fs.h | 8 ++++++++
include/uapi/linux/fs.h | 5 ++++-
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 70329c81be31..d725c194243c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -185,6 +185,9 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
/* File supports async nowait buffered writes */
#define FMODE_BUF_WASYNC ((__force fmode_t)0x80000000)
+/* File supports atomic writes */
+#define FMODE_CAN_ATOMIC_WRITE ((__force fmode_t)0x100000000)
Have you even tried to compile that on e.g. arm?
i386 and now arm32, and no grumblings.
I think that the issue is that we only ever do a bitwise OR or test that
bit 33 for a 32b value, and it is a void operation and ignored.
However if I have file.f_mode = FMODE_CAN_ATOMIC_WRITE and compile for
arm32, then it complains.
