On Wed, 2013-01-09 at 13:58 -0600, Dave Kleikamp wrote: > This patchset was begun by Zach Brown and was originally submitted for > review in October, 2009. Feedback was positive, and I have picked up > where he left off, porting his patches to the latest mainline kernel > and adding support more file systems. > > This patch series adds a kernel interface to fs/aio.c so that kernel code can > issue concurrent asynchronous IO to file systems. It adds an aio command and > file system methods which specify io memory with pages instead of userspace > addresses. > > This series was written to reduce the current overhead loop imposes by > performing synchronus buffered file system IO from a kernel thread. These > patches turn loop into a light weight layer that translates bios into iocbs. > > It introduces new file ops, read_iter() and write_iter(), that replace the > aio_read() and aio_write() operations. The iov_iter structure can now contain > either a user-space iovec or a kernel-space bio_vec. Since it would be > overly complicated to replace every instance of aio_read() and aio_write(), > the old operations are not removed, but file systems implementing the new > ones need not keep the old ones. > > Changes from V4 include: > * moved iov-iter.c from mm/ to fs/ > * removed dio_aligned helper > * insured that FUA write to loop device is committed to media > * removed no-longer-used REQ_KERNEL define > > These patches apply to 3.8-rc2 and are also available at: > git://github.com/kleikamp/linux-shaggy.git loop_2013_01_04 > > My hopes are that this patchset is finally ready for linux-next. Just a note that we at parallels are anxiously awaiting this too. Our rewrite of the linux loop device to be more efficient (and not double cache) depends on this work. I should also note that we've been testing these patches (albeit backported to a RHEL kernel as a current work base) with no problems reported so far. James -- 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
