Jan Kara wrote: >> I am wondering if it is useful to add another mode to advise block >> allocation policy? Something like indicating which physical block/block >> group to allocate from (goal), and whether ask for strict contigous >> blocks. This will help preallocation or reservation to choose the right >> blocks for the file. > Yes, I also think this would be useful so you can "guide" > preallocation for things like defragmentation (e.g. preallocate space > for the file being defragmented and move the file to it). Hints & policies for allocation would certainly be useful, but I think they belong outside this interface. i.e. you could flag an inode for whatever allocation you choose, and -then- call posix_fallocate so that the allocator will take the hints you've given it. See also this blurb from the posix_fallocate definition: "It is implementation-defined whether a previous posix_fadvise() call influences allocation strategy." FWIW I don't see a lot of point in asking for "strict contiguous blocks" - the allocator will presumeably try to do this in any case, and I'm not sure when you would want to fail if you get more than one extent...? -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
