Hi, O_DIRECT requires alignment to the underlying device's logical block size. It used to be pretty safe to assume this was 512 bytes, but that's no longer the case with the introduction of 4k logical sector size devices. Feel free to change the wording in the man page as you see fit, but here's an example of how it might be fixed. Cheers, Jeff Signed-off-by: Jeff Moyer <jmoyer@xxxxxxxxxx> diff --git a/man2/open.2 b/man2/open.2 index ff3aa88..fae90d2 100644 --- a/man2/open.2 +++ b/man2/open.2 @@ -769,8 +769,8 @@ operation in Under Linux 2.4, transfer sizes, and the alignment of the user buffer and the file offset must all be multiples of the logical block size of the file system. -Under Linux 2.6, alignment to 512-byte boundaries -suffices. +Under Linux 2.6, alignment to the underlying device's logical block +size suffices. .LP The .B O_DIRECT -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
