On Sun, Feb 09, 2014 at 11:36:43PM +0000, Al Viro wrote: > A couple of fixes, both -stable fodder. O_SYNC bug is > fairly old... Please, pull from the usual place - > git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git for-linus > > Shortlog: > Al Viro (2): > fix O_SYNC|O_APPEND syncing the wrong range on write() As i pointed out in a private thread this doesn't fix XFS. It passes a private "pos" variable to generic_write_checks() and so iocb->ki_pos never gets updated to point at the new EOF when O_APPEND is set. Hence the code inthe above commit is still syncing the wrong range. Indeed, I think that __generic_file_aio_write has the same problem. It gets called from generic_file_aio_write() like so: ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); And __generic_file_aio_write() does this: pos = *ppos; .... err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); and the updated pos value on O_APPEND writes is never folded back into ppos. Hence the later call to generic_write_sync() still has the wrong range.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
