On Thu, May 07, 2009 at 04:20:29PM +0530, Aneesh Kumar K.V wrote: > This avoid multiple get_block calls during write. Now that we have > unwritten buffer marked as mapped, we need to make sure writepages > will handle unwritten buffer_heads also. > > With this patch we have the below: > > ext4_ext_get_block returns unmapped, unwritten, buffer head when called with > create = 0 for prealloc space. This make sure we handle the read path and non > delalloc case correctly. Even though the buffer head is marked unmapped we > have valid b_blocknr and b_bdev values in the buffer_head. > > ext4_da_get_block_prep called for block resrevation will now return mapped, > unwritten, new buffer_head for prealloc space. This make sure we don't do > multiple get_block calls for write to same offset. Also marking it new make > sure sub-block zeroing of buffered writes happen correctly. Can you clarify this patch description. Is this only about avoiding multiple calls to get_block_*(), or does this also fix some potential filesystem corruption bugs? And how does this fit in with the other patches you've submitted? Thanks, - Ted -- 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
