This patchset uses VFS ITER_BVEC for reading/writing loop backing file, and basically it is a rewriting of Christoph Hellwig's post in [1].
With this change, loop code becomes much cleaner than before, and it is also a simplication for reading/writing backing file inside kernel. Another benifit is that one extra page copy is avoided for READ in case of none_transfer. This patchset passes xfstest test(ext4, -g auto) over loop block devices. The patch 3/3 depends a bit on Christoph's kiocb split patches which have been in -next for a while, so tree dependency(not build depend, just behaviour depend) should be considered if it is to be merged to 4.0. The next step is to add AIO/O_DIRECT support for reading/writing backing file against this patchset if no one objects, so that double cache can be avoided. [1], loop: convert to vfs_bvec_write http://marc.info/?l=linux-fsdevel&m=142159370107007&w=2 [2], kiocb split patchset http://marc.info/?t=142238145800004&r=1&w=2 Thanks, Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/