On 31/08/2020 16:32, Rich Felker wrote:
The pwrite function, originally defined by POSIX (thus the "p"), is
defined to ignore O_APPEND and write at the offset passed as its
argument. However, historically Linux honored O_APPEND if set and
ignored the offset. This cannot be changed due to stability policy,
but is documented in the man page as a bug.
Now that there's a pwritev2 syscall providing a superset of the pwrite
functionality that has a flags argument, the conforming behavior can
be offered to userspace via a new flag. Since pwritev2 checks flag
validity (in kiocb_set_rw_flags) and reports unknown ones with
EOPNOTSUPP, callers will not get wrong behavior on old kernels that
don't support the new flag; the error is reported and the caller can
decide how to handle it.
Signed-off-by: Rich Felker <dalias@xxxxxxxx>
What about updating the linux man pages for this flag?
If someone gives me a description of RWF_NOAPPEND for
rehttps://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/man/man2/readv.2,
then I can do it.
