On Wed, May 19, 2021 at 02:00:38PM +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.
Soooo... how close are we to enabling reflink for DAX?
I <cough> got rid of the lockouts in xfs_super.c and ran a quick
fstests, which showed a number of odd regressions where dedupe tests
that were supposed to fail with EBADE didn't and a bunch of clonerange
tests failed with EINVAL:
generic/122 - output mismatch (see /var/tmp/fstests/generic/122.out.bad)
--- tests/generic/122.out 2021-05-13 11:47:55.665860364 -0700
+++ /var/tmp/fstests/generic/122.out.bad 2021-05-25 17:24:03.333270522 -0700
@@ -4,7 +4,8 @@
5e3501f97fd2669babfcbd3e1972e833 TEST_DIR/test-122/file2
Files 1-2 do not match (intentional)
(Fail to) dedupe the middle blocks together
-XFS_IOC_FILE_EXTENT_SAME: Extents did not match.
+deduped 131072/131072 bytes at offset 262144
+128 KiB, 1 ops; 0.0000 sec (12.207 GiB/sec and 100000.0000 ops/sec)
Compare sections
...
(Run 'diff -u /tmp/fstests/tests/generic/122.out /var/tmp/fstests/generic/122.out.bad' to see the entire diff)
generic/136 - output mismatch (see /var/tmp/fstests/generic/136.out.bad)
--- tests/generic/136.out 2021-05-13 11:47:55.668860355 -0700
+++ /var/tmp/fstests/generic/136.out.bad 2021-05-25 17:24:05.773367756 -0700
@@ -7,7 +7,8 @@
Dedupe the last blocks together
1->2
1->3
-XFS_IOC_FILE_EXTENT_SAME: Extents did not match.
+deduped 37/37 bytes at offset 65536
+37.000000 bytes, 1 ops; 0.0000 sec (1.960 MiB/sec and 55555.5556 ops/sec)
c4fd505be25a0c91bcca9f502b9a8156 TEST_DIR/test-136/file1
...
(Run 'diff -u /tmp/fstests/tests/generic/136.out /var/tmp/fstests/generic/136.out.bad' to see the entire diff)
generic/164 - output mismatch (see /var/tmp/fstests/generic/164.out.bad)
--- tests/generic/164.out 2021-05-13 11:47:55.674860338 -0700
+++ /var/tmp/fstests/generic/164.out.bad 2021-05-25 17:25:33.339738197 -0700
@@ -2,4 +2,1028 @@
Format and mount
Initialize files
Reflink and reread the files!
+XFS_IOC_CLONE_RANGE: Invalid argument
+XFS_IOC_CLONE_RANGE: Invalid argument
+XFS_IOC_CLONE_RANGE: Invalid argument
+XFS_IOC_CLONE_RANGE: Invalid argument
...
(Run 'diff -u /tmp/fstests/tests/generic/164.out /var/tmp/fstests/generic/164.out.bad' to see the entire diff)
generic/165 - output mismatch (see /var/tmp/fstests/generic/165.out.bad)
--- tests/generic/165.out 2021-05-13 11:47:55.674860338 -0700
+++ /var/tmp/fstests/generic/165.out.bad 2021-05-25 17:25:45.247685323 -0700
@@ -2,4 +2,1028 @@
Format and mount
Initialize files
Reflink and dio reread the files!
+XFS_IOC_CLONE_RANGE: Invalid argument
+XFS_IOC_CLONE_RANGE: Invalid argument
+XFS_IOC_CLONE_RANGE: Invalid argument
+XFS_IOC_CLONE_RANGE: Invalid argument
...
(Run 'diff -u /tmp/fstests/tests/generic/165.out /var/tmp/fstests/generic/165.out.bad' to see the entire diff)
generic/175 - output mismatch (see /var/tmp/fstests/generic/175.out.bad)
--- tests/generic/175.out 2021-05-13 11:47:55.676860332 -0700
+++ /var/tmp/fstests/generic/175.out.bad 2021-05-25 17:29:55.060917807 -0700
@@ -3,3 +3,4 @@
Create a one block file
Create extents
Reflink the big file
+XFS_IOC_CLONE_RANGE: Invalid argument
...
(Run 'diff -u /tmp/fstests/tests/generic/175.out /var/tmp/fstests/generic/175.out.bad' to see the entire diff)
generic/327 - output mismatch (see /var/tmp/fstests/generic/327.out.bad)
--- tests/generic/327.out 2021-05-13 11:47:55.704860251 -0700
+++ /var/tmp/fstests/generic/327.out.bad 2021-05-25 17:35:22.338448231 -0700
@@ -7,6 +7,6 @@
root 0 0 0
fsgqa 2048 0 1024
Try to reflink again
-cp: failed to clone 'SCRATCH_MNT/test-327/file3' from 'SCRATCH_MNT/test-327/file1': Disk quota exceeded
+cp: failed to clone 'SCRATCH_MNT/test-327/file3' from 'SCRATCH_MNT/test-327/file1': Invalid argument
root 0 0 0
fsgqa 2048 0 1024
...
(Run 'diff -u /tmp/fstests/tests/generic/327.out /var/tmp/fstests/generic/327.out.bad' to see the entire diff)
generic/516 - output mismatch (see /var/tmp/fstests/generic/516.out.bad)
--- tests/generic/516.out 2021-05-13 11:47:55.739860150 -0700
+++ /var/tmp/fstests/generic/516.out.bad 2021-05-25 17:41:58.144177193 -0700
@@ -4,7 +4,8 @@
39578c21e2cb9f6049b1cf7fc7be12a6 TEST_DIR/test-516/file2
Files 1-2 do not match (intentional)
(partial) dedupe the middle blocks together
-XFS_IOC_FILE_EXTENT_SAME: Extents did not match.
+deduped XXXX/XXXX bytes at offset XXXX
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
Compare sections
...
(Run 'diff -u /tmp/fstests/tests/generic/516.out /var/tmp/fstests/generic/516.out.bad' to see the entire diff)
generic/517 - output mismatch (see /var/tmp/fstests/generic/517.out.bad)
--- tests/generic/517.out 2021-05-13 11:47:55.739860150 -0700
+++ /var/tmp/fstests/generic/517.out.bad 2021-05-25 17:41:59.352000318 -0700
@@ -33,8 +33,7 @@
0786532
wrote 100/100 bytes at offset 0
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-deduped 100/100 bytes at offset 655360
-XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+XFS_IOC_FILE_EXTENT_SAME: Invalid argument
File content after second deduplication:
...
(Run 'diff -u /tmp/fstests/tests/generic/517.out /var/tmp/fstests/generic/517.out.bad' to see the entire diff)
generic/518 1s
generic/540 - output mismatch (see /var/tmp/fstests/generic/540.out.bad)
--- tests/generic/540.out 2021-05-13 11:47:55.743860139 -0700
+++ /var/tmp/fstests/generic/540.out.bad 2021-05-25 17:42:01.999613949 -0700
@@ -7,8 +7,9 @@
6366fd359371414186688a0ef6988893 SCRATCH_MNT/test-540/file3
6366fd359371414186688a0ef6988893 SCRATCH_MNT/test-540/file3.chk
reflink across the transition
+XFS_IOC_CLONE_RANGE: Invalid argument
Compare files
bdbcf02ee0aa977795a79d25fcfdccb1 SCRATCH_MNT/test-540/file1
5a5221017d3ab8fd7583312a14d2ba80 SCRATCH_MNT/test-540/file2
...
(Run 'diff -u /tmp/fstests/tests/generic/540.out /var/tmp/fstests/generic/540.out.bad' to see the entire diff)
generic/541 - output mismatch (see /var/tmp/fstests/generic/541.out.bad)
--- tests/generic/541.out 2021-05-13 11:47:55.743860139 -0700
+++ /var/tmp/fstests/generic/541.out.bad 2021-05-25 17:42:03.623377997 -0700
@@ -8,9 +8,10 @@
6366fd359371414186688a0ef6988893 SCRATCH_MNT/test-541/file3
6366fd359371414186688a0ef6988893 SCRATCH_MNT/test-541/file3.chk
reflink across the transition
+XFS_IOC_CLONE_RANGE: Invalid argument
Compare files
bdbcf02ee0aa977795a79d25fcfdccb1 SCRATCH_MNT/test-541/file1
-51a300aae3a4b4eaa023876a397e01ef SCRATCH_MNT/test-541/file2
...
(Run 'diff -u /tmp/fstests/tests/generic/541.out /var/tmp/fstests/generic/541.out.bad' to see the entire diff)
generic/542 - output mismatch (see /var/tmp/fstests/generic/542.out.bad)
--- tests/generic/542.out 2021-05-13 11:47:55.743860139 -0700
+++ /var/tmp/fstests/generic/542.out.bad 2021-05-25 17:42:05.487108030 -0700
@@ -7,8 +7,9 @@
6366fd359371414186688a0ef6988893 SCRATCH_MNT/test-542/file3
6366fd359371414186688a0ef6988893 SCRATCH_MNT/test-542/file3.chk
reflink across the transition
+XFS_IOC_CLONE_RANGE: Invalid argument
Compare files
bdbcf02ee0aa977795a79d25fcfdccb1 SCRATCH_MNT/test-542/file1
5a5221017d3ab8fd7583312a14d2ba80 SCRATCH_MNT/test-542/file2
...
(Run 'diff -u /tmp/fstests/tests/generic/542.out /var/tmp/fstests/generic/542.out.bad' to see the entire diff)
generic/543 - output mismatch (see /var/tmp/fstests/generic/543.out.bad)
--- tests/generic/543.out 2021-05-13 11:47:55.744860136 -0700
+++ /var/tmp/fstests/generic/543.out.bad 2021-05-25 17:42:07.386833815 -0700
@@ -8,9 +8,10 @@
6366fd359371414186688a0ef6988893 SCRATCH_MNT/test-543/file3
6366fd359371414186688a0ef6988893 SCRATCH_MNT/test-543/file3.chk
reflink across the transition
+XFS_IOC_CLONE_RANGE: Invalid argument
Compare files
bdbcf02ee0aa977795a79d25fcfdccb1 SCRATCH_MNT/test-543/file1
-d93123af536c8c012f866ea383a905ce SCRATCH_MNT/test-543/file2
...
(Run 'diff -u /tmp/fstests/tests/generic/543.out /var/tmp/fstests/generic/543.out.bad' to see the entire diff)
That's all the failures to the end of the generic group; I cut it off so
that I could schedule my regular nightly testing runs.
--D
>
> Changes from V5:
> - Fix the lock order of xfs_inode in xfs_mmaplock_two_inodes_and_break_dax_layout()
> - move dax_remap_file_range_prep() to fs/dax.c
> - change type of length to uint64_t in dax_iomap_cow_copy()
> - fix mistake in dax_iomap_zero()
>
> 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
>
> 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-rc2 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 | 216 ++++++++++++++++++++++++++++++++++++-----
> fs/iomap/apply.c | 52 ++++++++++
> fs/iomap/buffered-io.c | 2 +-
> fs/remap_range.c | 36 +++++--
> fs/xfs/xfs_bmap_util.c | 3 +-
> fs/xfs/xfs_file.c | 11 +--
> fs/xfs/xfs_inode.c | 57 +++++++++++
> fs/xfs/xfs_inode.h | 1 +
> fs/xfs/xfs_iomap.c | 38 +++++++-
> fs/xfs/xfs_iomap.h | 24 +++++
> fs/xfs/xfs_iops.c | 7 +-
> fs/xfs/xfs_reflink.c | 15 +--
> include/linux/dax.h | 11 ++-
> include/linux/fs.h | 12 ++-
> include/linux/iomap.h | 7 +-
> 15 files changed, 431 insertions(+), 61 deletions(-)
>
> --
> 2.31.1
>
>
>
