On Mon, Jun 25, 2007 at 03:56:25PM -0600, Andreas Dilger wrote: > On Jun 25, 2007 19:20 +0530, Amit K. Arora wrote: > > @@ -2499,7 +2500,8 @@ long ext4_fallocate(struct inode *inode, > > * currently supporting (pre)allocate mode for extent-based > > * files _only_ > > */ > > - if (mode != FA_ALLOCATE || !(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) > > + if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) || > > + !(mode == FA_ALLOCATE || mode == FA_RESV_SPACE)) > > return -EOPNOTSUPP; > > This should probably just check for the individual flags it can support > (e.g. no FA_FL_DEALLOC, no FA_FL_DEL_DATA). Hmm.. I am thinking of a scenario when the file system supports some individual flags, but does not support a particular combination of them. Just for example sake, assume we have FA_ZERO_SPACE mode also. Now, if a file system supports FA_ZERO_SPACE, FA_ALLOCATE, FA_DEALLOCATE and FA_RESV_SPACE; and no other mode (i.e. FA_UNRESV_SPACE is not supported for some reason). This means that although we support FA_FL_DEALLOC, FA_FL_KEEP_SIZE and FA_FL_DEL_DATA flags, but we do not support the combination of all these flags (which is nothing but FA_UNRESV_SPACE). > I also thought another proposed flag was to determine whether mtime (and > maybe ctime) is changed when doing prealloc/dealloc space? Default should > probably be to change mtime/ctime, and have FA_FL_NO_MTIME. Someone else > should decide if we want to allow changing the file w/o changing ctime, if > that is required even though the file is not visibly changing. Maybe the > ctime update should be implicit if the size or mtime are changing? Is it really required ? I mean, why should we allow users not to update ctime/mtime even if the file metadata/data gets updated ? It sounds a bit "unnatural" to me. Is there any application scenario in your mind, when you suggest of giving this flexibility to userspace ? I think, modifying ctime/mtime should be dependent on the other flags. E.g., if we do not zero out data blocks on allocation/deallocation, update only ctime. Otherwise, update ctime and mtime both. -- Regards, Amit Arora - 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
