Curt Wohlgemuth wrote: > We've recently seen some interesting behavior with ftruncate() > following a fallocate() call on ext4, and would like to know if this > is intended or not. > > The sequence used from user space: > > fd = open() > fallocate(fd, FALLOC_FL_KEEP_SIZE, 8MB) > write(fd, buf, 64KB) > ftruncate(fd, 64KB) > close(fd) > > Since inode_setattr() only does something if the input size is not the > same as inode->i_size, the ftruncate() call above does nothing; no > blocks from the fallocate() are freed up. > > Yes, removing the KEEP_SIZE flag gets the behavior I'm expecting, but > KEEP_SIZE is quite convenient in recovering from errors. > > I would have thought that ftruncate() would alter i_disksize even if > this value is different from i_size. > > Any comments? I looked at other Linux file systems, and none that I > saw that support fallocate() have this issue. > > Thanks, > Curt Yep, I think you've found a bug, I will look into this soon unless someone beats me to it :) -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
