On Mon, Jun 25, 2007 at 03:52:39PM -0600, Andreas Dilger wrote: > On Jun 25, 2007 19:15 +0530, Amit K. Arora wrote: > > +#define FA_FL_DEALLOC 0x01 /* default is allocate */ > > +#define FA_FL_KEEP_SIZE 0x02 /* default is extend/shrink size */ > > +#define FA_FL_DEL_DATA 0x04 /* default is keep written data on DEALLOC */ > > In XFS one of the (many) ALLOC modes is to zero existing data on allocate. No, none of the XFS allocation modes do that. XFS_IOC_ALLOCSP, which does write zeros to disk, only allocates and writes zeros in the range between the old file size and the new file size. XFS_IOC_RESVSP, which alocates unwritten extents, only allocates where extents do not currently exist. It does not zero existing extents. IOWs, you can't overwrite existing data with XFS preallocation. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group - 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
