| Message ID | 20210511030933.3080921-1-ruansy.fnst@fujitsu.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | fsdax,xfs: Add reflink&dedupe support for fsdax | expand |
On Tue, May 11, 2021 at 11:09:26AM +0800, Shiyang Ruan wrote: > This patchset is attempt to add CoW support for fsdax, and take XFS, > which has both reflink and fsdax feature, as an example. Slightly off topic, but I noticed all my pmem disappeared once I rolled forward to 5.13-rc1. Am I the only lucky one? Qemu 4.2, with fake memory devices backed by tmpfs files -- info qtree says they're there, but the kernel doesn't show anything in /proc/iomem. --D > Changes from V4: > - Fix the mistake of breaking dax layout for two inodes > - Add CONFIG_FS_DAX judgement for fsdax code in remap_range.c > - Fix other small problems and mistakes > > Changes from V3: > - Take out the first 3 patches as a cleanup patchset[1], which has been > sent yesterday. > - Fix usage of code in dax_iomap_cow_copy() > - Add comments for macro definitions > - Fix other code style problems and mistakes > > One of the key mechanism need to be implemented in fsdax is CoW. Copy > the data from srcmap before we actually write data to the destance > iomap. And we just copy range in which data won't be changed. > > Another mechanism is range comparison. In page cache case, readpage() > is used to load data on disk to page cache in order to be able to > compare data. In fsdax case, readpage() does not work. So, we need > another compare data with direct access support. > > With the two mechanisms implemented in fsdax, we are able to make reflink > and fsdax work together in XFS. > > Some of the patches are picked up from Goldwyn's patchset. I made some > changes to adapt to this patchset. > > > (Rebased on v5.13-rc1 and patchset[1]) > [1]: https://lkml.org/lkml/2021/4/22/575 > > Shiyang Ruan (7): > fsdax: Introduce dax_iomap_cow_copy() > fsdax: Replace mmap entry in case of CoW > fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero > iomap: Introduce iomap_apply2() for operations on two files > fsdax: Dedup file range to use a compare function > fs/xfs: Handle CoW for fsdax write() path > fs/xfs: Add dax dedupe support > > fs/dax.c | 206 +++++++++++++++++++++++++++++++++++------ > fs/iomap/apply.c | 52 +++++++++++ > fs/iomap/buffered-io.c | 2 +- > fs/remap_range.c | 57 ++++++++++-- > fs/xfs/xfs_bmap_util.c | 3 +- > fs/xfs/xfs_file.c | 11 +-- > fs/xfs/xfs_inode.c | 66 ++++++++++++- > fs/xfs/xfs_inode.h | 1 + > fs/xfs/xfs_iomap.c | 61 +++++++++++- > fs/xfs/xfs_iomap.h | 4 + > fs/xfs/xfs_iops.c | 7 +- > fs/xfs/xfs_reflink.c | 15 +-- > include/linux/dax.h | 7 +- > include/linux/fs.h | 12 ++- > include/linux/iomap.h | 7 +- > 15 files changed, 449 insertions(+), 62 deletions(-) > > -- > 2.31.1 > > >
> -----Original Message----- > From: Darrick J. Wong <djwong@kernel.org> > Sent: Tuesday, May 11, 2021 11:57 AM > Subject: Re: [PATCH v5 0/7] fsdax,xfs: Add reflink&dedupe support for fsdax > > On Tue, May 11, 2021 at 11:09:26AM +0800, Shiyang Ruan wrote: > > This patchset is attempt to add CoW support for fsdax, and take XFS, > > which has both reflink and fsdax feature, as an example. > > Slightly off topic, but I noticed all my pmem disappeared once I rolled forward to > 5.13-rc1. Am I the only lucky one? Qemu 4.2, with fake memory devices > backed by tmpfs files -- info qtree says they're there, but the kernel doesn't show > anything in /proc/iomem. I have the same situation on 5.13-rc1 too. (Qemu 5.2.0, fake memory device backed by files) I tested this code in v5.12-rc8 and then rebased it to v5.13-rc1... It's my bad for not testing again. -- Thanks, Ruan Shiyang. > > --D > > > Changes from V4: > > - Fix the mistake of breaking dax layout for two inodes > > - Add CONFIG_FS_DAX judgement for fsdax code in remap_range.c > > - Fix other small problems and mistakes > > > > Changes from V3: > > - Take out the first 3 patches as a cleanup patchset[1], which has been > > sent yesterday. > > - Fix usage of code in dax_iomap_cow_copy() > > - Add comments for macro definitions > > - Fix other code style problems and mistakes > > > > One of the key mechanism need to be implemented in fsdax is CoW. Copy > > the data from srcmap before we actually write data to the destance > > iomap. And we just copy range in which data won't be changed. > > > > Another mechanism is range comparison. In page cache case, readpage() > > is used to load data on disk to page cache in order to be able to > > compare data. In fsdax case, readpage() does not work. So, we need > > another compare data with direct access support. > > > > With the two mechanisms implemented in fsdax, we are able to make > > reflink and fsdax work together in XFS. > > > > Some of the patches are picked up from Goldwyn's patchset. I made > > some changes to adapt to this patchset. > > > > > > (Rebased on v5.13-rc1 and patchset[1]) > > [1]: https://lkml.org/lkml/2021/4/22/575 > > > > Shiyang Ruan (7): > > fsdax: Introduce dax_iomap_cow_copy() > > fsdax: Replace mmap entry in case of CoW > > fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero > > iomap: Introduce iomap_apply2() for operations on two files > > fsdax: Dedup file range to use a compare function > > fs/xfs: Handle CoW for fsdax write() path > > fs/xfs: Add dax dedupe support > > > > fs/dax.c | 206 > +++++++++++++++++++++++++++++++++++------ > > fs/iomap/apply.c | 52 +++++++++++ > > fs/iomap/buffered-io.c | 2 +- > > fs/remap_range.c | 57 ++++++++++-- > > fs/xfs/xfs_bmap_util.c | 3 +- > > fs/xfs/xfs_file.c | 11 +-- > > fs/xfs/xfs_inode.c | 66 ++++++++++++- > > fs/xfs/xfs_inode.h | 1 + > > fs/xfs/xfs_iomap.c | 61 +++++++++++- > > fs/xfs/xfs_iomap.h | 4 + > > fs/xfs/xfs_iops.c | 7 +- > > fs/xfs/xfs_reflink.c | 15 +-- > > include/linux/dax.h | 7 +- > > include/linux/fs.h | 12 ++- > > include/linux/iomap.h | 7 +- > > 15 files changed, 449 insertions(+), 62 deletions(-) > > > > -- > > 2.31.1 > > > > > >
This patchset is attempt to add CoW support for fsdax, and take XFS, which has both reflink and fsdax feature, as an example. Changes from V4: - Fix the mistake of breaking dax layout for two inodes - Add CONFIG_FS_DAX judgement for fsdax code in remap_range.c - Fix other small problems and mistakes Changes from V3: - Take out the first 3 patches as a cleanup patchset[1], which has been sent yesterday. - Fix usage of code in dax_iomap_cow_copy() - Add comments for macro definitions - Fix other code style problems and mistakes One of the key mechanism need to be implemented in fsdax is CoW. Copy the data from srcmap before we actually write data to the destance iomap. And we just copy range in which data won't be changed. Another mechanism is range comparison. In page cache case, readpage() is used to load data on disk to page cache in order to be able to compare data. In fsdax case, readpage() does not work. So, we need another compare data with direct access support. With the two mechanisms implemented in fsdax, we are able to make reflink and fsdax work together in XFS. Some of the patches are picked up from Goldwyn's patchset. I made some changes to adapt to this patchset. (Rebased on v5.13-rc1 and patchset[1]) [1]: https://lkml.org/lkml/2021/4/22/575 Shiyang Ruan (7): fsdax: Introduce dax_iomap_cow_copy() fsdax: Replace mmap entry in case of CoW fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero iomap: Introduce iomap_apply2() for operations on two files fsdax: Dedup file range to use a compare function fs/xfs: Handle CoW for fsdax write() path fs/xfs: Add dax dedupe support fs/dax.c | 206 +++++++++++++++++++++++++++++++++++------ fs/iomap/apply.c | 52 +++++++++++ fs/iomap/buffered-io.c | 2 +- fs/remap_range.c | 57 ++++++++++-- fs/xfs/xfs_bmap_util.c | 3 +- fs/xfs/xfs_file.c | 11 +-- fs/xfs/xfs_inode.c | 66 ++++++++++++- fs/xfs/xfs_inode.h | 1 + fs/xfs/xfs_iomap.c | 61 +++++++++++- fs/xfs/xfs_iomap.h | 4 + fs/xfs/xfs_iops.c | 7 +- fs/xfs/xfs_reflink.c | 15 +-- include/linux/dax.h | 7 +- include/linux/fs.h | 12 ++- include/linux/iomap.h | 7 +- 15 files changed, 449 insertions(+), 62 deletions(-)