I have three questions regarding the XFS implementation of ftruncate(). In the block device driver, I can see that writes are being performed to the last block of previously written file when ftruncate() is called. I believe that I found ftruncate() in the XFS sources, but all I see is the filesize being updated in the inode. So if ftruncate() is writing to the last block, it appears to be a triggered event. To test, I added printk() statements in the block device driver that outputs jiffies for write operations. A file is created and written (~1 MiB), and then truncated to 8192 via ftruncate(). The original write to file happens about 20 jiffies before the call to ftruncate(). When looking at the output, there is an additional write to what is the last block of the truncated file, which reports the same jiffies as the call to ftruncate(). I am not reporting this as a bug, simply looking for more information, as it was not something that I expected to happen. Does ftruncate() actually write to the last block of the file? If not, any thoughts on what would be? It only happens when ftruncate() is called. Where in the XFS kernel code is ftruncate() implemented? I searched around, but have no confidence that what I see is actually the ftruncate() implementation. If ftruncate() does write to the last block of the file, why does it do so? _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
