https://bugzilla.kernel.org/show_bug.cgi?id=218850 Theodore Tso (tytso@xxxxxxx) changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED CC| |tytso@xxxxxxx Resolution|--- |INVALID --- Comment #3 from Theodore Tso (tytso@xxxxxxx) --- Hint: check the return value of all system calls. In particular, check to see what the read(fd_b, buf_4, 73728) returns. Check to see what the size of the file is after write(fd_a, buf_15, 9900), and then reflect on what happens if the read ends up hitting the end of file marker, and what the offset of fd_b is after the short read when hitting EOF. Finally, read the documentation for the O_DIRECT flag in the NOTES section of the open man page[1], and understand what the requirements are for O_DIRECT writes, in particular about the alignment requirements are of the starting offset when performing an O_DIRECT write (or O_DIRECT) read. Then also check on the errno return (for example replace the printf("write failure\n") with perror("write"). [1] https://man7.org/linux/man-pages/man2/open.2.html In any case, this is not a bug, and this is not a good place for you to be asking for instruction in basic Unix system call programming. -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
