* Re: [mm/readahead] a0b99df1aa: xfstests.xfs.421.fail [not found] <20220221080217.GB835@xsang-OptiPlex-9020> @ 2022-02-21 13:56 ` Matthew Wilcox 2022-02-21 20:55 ` Dave Chinner 0 siblings, 1 reply; 6+ messages in thread From: Matthew Wilcox @ 2022-02-21 13:56 UTC (permalink / raw) To: kernel test robot Cc: lkp, lkp, LKML, Darrick J. Wong, linux-xfs, Christoph Hellwig On Mon, Feb 21, 2022 at 04:02:18PM +0800, kernel test robot wrote: > commit: a0b99df1aa37d714eb80be5fb54efd56c88a3336 ("mm/readahead: Add large folio readahead") > xfs/420 - output mismatch (see /lkp/benchmarks/xfstests/results//xfs/420.out.bad) > --- tests/xfs/420.out 2022-02-17 11:55:00.000000000 +0000 > +++ /lkp/benchmarks/xfstests/results//xfs/420.out.bad 2022-02-20 20:34:22.430378506 +0000 > @@ -13,9 +13,7 @@ > Seek holes and data in file2 > Whence Result > DATA 0 > -HOLE 131072 > -DATA 196608 > -HOLE 262144 > +HOLE 524288 Confirm this test now fails. I don't think it's actually a bug, though. I think the test is now using larger pages to cache the file, and it fails to report that there's a hole in the file. Maybe there actually isn't a hole in the file any more; using larger pages to cache the file means we'll now write more data than we used to. Adding XFS people for their thoughts. Complete output: $ diff -u ../ktest/tests/xfstests/tests/xfs/420.out ktest-out/xfstests/xfs/420.out.bad --- ../ktest/tests/xfstests/tests/xfs/420.out 2021-07-05 15:49:45.539887305 -0400 +++ ktest-out/xfstests/xfs/420.out.bad 2022-02-21 08:14:40.000000000 -0500 @@ -13,9 +13,7 @@ Seek holes and data in file2 Whence Result DATA 0 -HOLE 131072 -DATA 196608 -HOLE 262144 +HOLE 524288 Compare files c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 @@ -28,9 +26,7 @@ Seek holes and data in file2 Whence Result DATA 0 -HOLE 131072 -DATA 196608 -HOLE 262144 +HOLE 524288 Compare files c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 So the file checksums are right, which means I didn't break the COW functionality. But we're no longer reporting a hole at 128k. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [mm/readahead] a0b99df1aa: xfstests.xfs.421.fail 2022-02-21 13:56 ` [mm/readahead] a0b99df1aa: xfstests.xfs.421.fail Matthew Wilcox @ 2022-02-21 20:55 ` Dave Chinner 2022-02-21 21:10 ` Matthew Wilcox 0 siblings, 1 reply; 6+ messages in thread From: Dave Chinner @ 2022-02-21 20:55 UTC (permalink / raw) To: Matthew Wilcox Cc: kernel test robot, lkp, lkp, LKML, Darrick J. Wong, linux-xfs, Christoph Hellwig On Mon, Feb 21, 2022 at 01:56:55PM +0000, Matthew Wilcox wrote: > On Mon, Feb 21, 2022 at 04:02:18PM +0800, kernel test robot wrote: > > commit: a0b99df1aa37d714eb80be5fb54efd56c88a3336 ("mm/readahead: Add large folio readahead") > > > xfs/420 - output mismatch (see /lkp/benchmarks/xfstests/results//xfs/420.out.bad) > > --- tests/xfs/420.out 2022-02-17 11:55:00.000000000 +0000 > > +++ /lkp/benchmarks/xfstests/results//xfs/420.out.bad 2022-02-20 20:34:22.430378506 +0000 > > @@ -13,9 +13,7 @@ > > Seek holes and data in file2 > > Whence Result > > DATA 0 > > -HOLE 131072 > > -DATA 196608 > > -HOLE 262144 > > +HOLE 524288 > > Confirm this test now fails. I don't think it's actually a bug, > though. I think the test is now using larger pages to cache the > file, and it fails to report that there's a hole in the file. > Maybe there actually isn't a hole in the file any more; using > larger pages to cache the file means we'll now write more data > than we used to. > > Adding XFS people for their thoughts. > > Complete output: > > $ diff -u ../ktest/tests/xfstests/tests/xfs/420.out ktest-out/xfstests/xfs/420.out.bad > --- ../ktest/tests/xfstests/tests/xfs/420.out 2021-07-05 15:49:45.539887305 -0400 > +++ ktest-out/xfstests/xfs/420.out.bad 2022-02-21 08:14:40.000000000 -0500 > @@ -13,9 +13,7 @@ > Seek holes and data in file2 > Whence Result > DATA 0 > -HOLE 131072 > -DATA 196608 > -HOLE 262144 > +HOLE 524288 > Compare files > c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 > 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 > @@ -28,9 +26,7 @@ > Seek holes and data in file2 > Whence Result > DATA 0 > -HOLE 131072 > -DATA 196608 > -HOLE 262144 > +HOLE 524288 > Compare files > c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 > 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 > > So the file checksums are right, which means I didn't break the COW > functionality. But we're no longer reporting a hole at 128k. Can you post the contents of the 420.full output file so we can see what the output of the various commands that are run are? e.g. things like cowextsize that is configured, etc? Cheers, Dave. -- Dave Chinner david@fromorbit.com ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [mm/readahead] a0b99df1aa: xfstests.xfs.421.fail 2022-02-21 20:55 ` Dave Chinner @ 2022-02-21 21:10 ` Matthew Wilcox 2022-02-21 21:43 ` Dave Chinner 0 siblings, 1 reply; 6+ messages in thread From: Matthew Wilcox @ 2022-02-21 21:10 UTC (permalink / raw) To: Dave Chinner Cc: kernel test robot, lkp, lkp, LKML, Darrick J. Wong, linux-xfs, Christoph Hellwig On Tue, Feb 22, 2022 at 07:55:29AM +1100, Dave Chinner wrote: > On Mon, Feb 21, 2022 at 01:56:55PM +0000, Matthew Wilcox wrote: > > On Mon, Feb 21, 2022 at 04:02:18PM +0800, kernel test robot wrote: > > > commit: a0b99df1aa37d714eb80be5fb54efd56c88a3336 ("mm/readahead: Add large folio readahead") > > > > > xfs/420 - output mismatch (see /lkp/benchmarks/xfstests/results//xfs/420.out.bad) > > > --- tests/xfs/420.out 2022-02-17 11:55:00.000000000 +0000 > > > +++ /lkp/benchmarks/xfstests/results//xfs/420.out.bad 2022-02-20 20:34:22.430378506 +0000 > > > @@ -13,9 +13,7 @@ > > > Seek holes and data in file2 > > > Whence Result > > > DATA 0 > > > -HOLE 131072 > > > -DATA 196608 > > > -HOLE 262144 > > > +HOLE 524288 > > > > Confirm this test now fails. I don't think it's actually a bug, > > though. I think the test is now using larger pages to cache the > > file, and it fails to report that there's a hole in the file. > > Maybe there actually isn't a hole in the file any more; using > > larger pages to cache the file means we'll now write more data > > than we used to. > > > > Adding XFS people for their thoughts. > > > > Complete output: > > > > $ diff -u ../ktest/tests/xfstests/tests/xfs/420.out ktest-out/xfstests/xfs/420.out.bad > > --- ../ktest/tests/xfstests/tests/xfs/420.out 2021-07-05 15:49:45.539887305 -0400 > > +++ ktest-out/xfstests/xfs/420.out.bad 2022-02-21 08:14:40.000000000 -0500 > > @@ -13,9 +13,7 @@ > > Seek holes and data in file2 > > Whence Result > > DATA 0 > > -HOLE 131072 > > -DATA 196608 > > -HOLE 262144 > > +HOLE 524288 > > Compare files > > c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 > > 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 > > @@ -28,9 +26,7 @@ > > Seek holes and data in file2 > > Whence Result > > DATA 0 > > -HOLE 131072 > > -DATA 196608 > > -HOLE 262144 > > +HOLE 524288 > > Compare files > > c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 > > 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 > > > > So the file checksums are right, which means I didn't break the COW > > functionality. But we're no longer reporting a hole at 128k. > > Can you post the contents of the 420.full output file so we can see > what the output of the various commands that are run are? e.g. > things like cowextsize that is configured, etc? Sure! It's short, so I've included it inline. meta-data=/dev/sdc isize=512 agcount=4, agsize=3670016 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=1, sparse=1, rmapbt=1 = reflink=1 bigtime=0 data = bsize=1024 blocks=14680064, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0, ftype=1 log =internal log bsize=1024 blocks=10240, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 Discarding blocks...Done. [0] /mnt/scratch/test-420 [524288] /mnt/scratch/test-420 wrote 131072/131072 bytes at offset 0 128 KiB, 128 ops; 0.0000 sec (1.327 GiB/sec and 1391304.3478 ops/sec) wrote 524288/524288 bytes at offset 0 512 KiB, 512 ops; 0.0003 sec (1.341 GiB/sec and 1406593.4066 ops/sec) wrote 131072/131072 bytes at offset 0 128 KiB, 128 ops; 0.0000 sec (1.822 GiB/sec and 1910447.7612 ops/sec) CoW the shared part then write into the empty part [524288] /mnt/scratch/test-420/file1 [524288] /mnt/scratch/test-420/file2 wrote 65536/65536 bytes at offset 0 64 KiB, 64 ops; 0.0001 sec (416.667 MiB/sec and 426666.6667 ops/sec) wrote 65536/65536 bytes at offset 196608 64 KiB, 64 ops; 0.0000 sec (1.695 GiB/sec and 1777777.7778 ops/sec) wrote 65536/65536 bytes at offset 0 64 KiB, 64 ops; 0.0000 sec (1.387 GiB/sec and 1454545.4545 ops/sec) wrote 65536/65536 bytes at offset 196608 64 KiB, 64 ops; 0.0000 sec (1.526 GiB/sec and 1600000.0000 ops/sec) xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file1"]: Invalid argument /mnt/scratch/test-420/file1: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..255]: 128..383 0 (128..383) 256 100000 1: [256..1023]: hole 768 xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file2"]: Invalid argument /mnt/scratch/test-420/file2: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..255]: 128..383 0 (128..383) 256 100000 1: [256..1023]: hole 768 xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file3"]: Invalid argument /mnt/scratch/test-420/file3: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..1023]: 512..1535 0 (512..1535) 1024 sync filesystem xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file1"]: Invalid argument /mnt/scratch/test-420/file1: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..127]: 128..255 0 (128..255) 128 1: [128..255]: 256..383 0 (256..383) 128 100000 2: [256..1023]: hole 768 xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file2"]: Invalid argument /mnt/scratch/test-420/file2: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..127]: 1536..1663 0 (1536..1663) 128 1: [128..255]: 256..383 0 (256..383) 128 100000 2: [256..383]: hole 128 3: [384..511]: 1920..2047 0 (1920..2047) 128 4: [512..1023]: hole 512 xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file3"]: Invalid argument /mnt/scratch/test-420/file3: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..1023]: 512..1535 0 (512..1535) 1024 Remount xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file1"]: Invalid argument /mnt/scratch/test-420/file1: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..127]: 128..255 0 (128..255) 128 1: [128..255]: 256..383 0 (256..383) 128 100000 2: [256..1023]: hole 768 xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file2"]: Invalid argument /mnt/scratch/test-420/file2: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..127]: 1536..1663 0 (1536..1663) 128 1: [128..255]: 256..383 0 (256..383) 128 100000 2: [256..383]: hole 128 3: [384..511]: 1920..2047 0 (1920..2047) 128 4: [512..1023]: hole 512 xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file3"]: Invalid argument /mnt/scratch/test-420/file3: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..1023]: 512..1535 0 (512..1535) 1024 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [mm/readahead] a0b99df1aa: xfstests.xfs.421.fail 2022-02-21 21:10 ` Matthew Wilcox @ 2022-02-21 21:43 ` Dave Chinner 2022-02-23 19:59 ` Matthew Wilcox 0 siblings, 1 reply; 6+ messages in thread From: Dave Chinner @ 2022-02-21 21:43 UTC (permalink / raw) To: Matthew Wilcox Cc: kernel test robot, lkp, lkp, LKML, Darrick J. Wong, linux-xfs, Christoph Hellwig On Mon, Feb 21, 2022 at 09:10:20PM +0000, Matthew Wilcox wrote: > On Tue, Feb 22, 2022 at 07:55:29AM +1100, Dave Chinner wrote: > > On Mon, Feb 21, 2022 at 01:56:55PM +0000, Matthew Wilcox wrote: > > > On Mon, Feb 21, 2022 at 04:02:18PM +0800, kernel test robot wrote: > > > > commit: a0b99df1aa37d714eb80be5fb54efd56c88a3336 ("mm/readahead: Add large folio readahead") > > > > > > > xfs/420 - output mismatch (see /lkp/benchmarks/xfstests/results//xfs/420.out.bad) > > > > --- tests/xfs/420.out 2022-02-17 11:55:00.000000000 +0000 > > > > +++ /lkp/benchmarks/xfstests/results//xfs/420.out.bad 2022-02-20 20:34:22.430378506 +0000 > > > > @@ -13,9 +13,7 @@ > > > > Seek holes and data in file2 > > > > Whence Result > > > > DATA 0 > > > > -HOLE 131072 > > > > -DATA 196608 > > > > -HOLE 262144 > > > > +HOLE 524288 > > > > > > Confirm this test now fails. I don't think it's actually a bug, > > > though. I think the test is now using larger pages to cache the > > > file, and it fails to report that there's a hole in the file. > > > Maybe there actually isn't a hole in the file any more; using > > > larger pages to cache the file means we'll now write more data > > > than we used to. > > > > > > Adding XFS people for their thoughts. > > > > > > Complete output: > > > > > > $ diff -u ../ktest/tests/xfstests/tests/xfs/420.out ktest-out/xfstests/xfs/420.out.bad > > > --- ../ktest/tests/xfstests/tests/xfs/420.out 2021-07-05 15:49:45.539887305 -0400 > > > +++ ktest-out/xfstests/xfs/420.out.bad 2022-02-21 08:14:40.000000000 -0500 > > > @@ -13,9 +13,7 @@ > > > Seek holes and data in file2 > > > Whence Result > > > DATA 0 > > > -HOLE 131072 > > > -DATA 196608 > > > -HOLE 262144 > > > +HOLE 524288 > > > Compare files > > > c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 > > > 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 > > > @@ -28,9 +26,7 @@ > > > Seek holes and data in file2 > > > Whence Result > > > DATA 0 > > > -HOLE 131072 > > > -DATA 196608 > > > -HOLE 262144 > > > +HOLE 524288 > > > Compare files > > > c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 > > > 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 > > > > > > So the file checksums are right, which means I didn't break the COW > > > functionality. But we're no longer reporting a hole at 128k. > > > > Can you post the contents of the 420.full output file so we can see > > what the output of the various commands that are run are? e.g. > > things like cowextsize that is configured, etc? > > Sure! It's short, so I've included it inline. Ok, I'll cut this up so it makes sense... > > > meta-data=/dev/sdc isize=512 agcount=4, agsize=3670016 blks > = sectsz=512 attr=2, projid32bit=1 > = crc=1 finobt=1, sparse=1, rmapbt=1 > = reflink=1 bigtime=0 > data = bsize=1024 blocks=14680064, imaxpct=25 > = sunit=0 swidth=0 blks > naming =version 2 bsize=4096 ascii-ci=0, ftype=1 > log =internal log bsize=1024 blocks=10240, version=2 > = sectsz=512 sunit=0 blks, lazy-count=1 > realtime =none extsz=4096 blocks=0, rtextents=0 > Discarding blocks...Done. > [0] /mnt/scratch/test-420 > [524288] /mnt/scratch/test-420 > wrote 131072/131072 bytes at offset 0 > 128 KiB, 128 ops; 0.0000 sec (1.327 GiB/sec and 1391304.3478 ops/sec) > wrote 524288/524288 bytes at offset 0 > 512 KiB, 512 ops; 0.0003 sec (1.341 GiB/sec and 1406593.4066 ops/sec) > wrote 131072/131072 bytes at offset 0 > 128 KiB, 128 ops; 0.0000 sec (1.822 GiB/sec and 1910447.7612 ops/sec) > CoW the shared part then write into the empty part > [524288] /mnt/scratch/test-420/file1 > [524288] /mnt/scratch/test-420/file2 > wrote 65536/65536 bytes at offset 0 > 64 KiB, 64 ops; 0.0001 sec (416.667 MiB/sec and 426666.6667 ops/sec) > wrote 65536/65536 bytes at offset 196608 > 64 KiB, 64 ops; 0.0000 sec (1.695 GiB/sec and 1777777.7778 ops/sec) > wrote 65536/65536 bytes at offset 0 > 64 KiB, 64 ops; 0.0000 sec (1.387 GiB/sec and 1454545.4545 ops/sec) > wrote 65536/65536 bytes at offset 196608 > 64 KiB, 64 ops; 0.0000 sec (1.526 GiB/sec and 1600000.0000 ops/sec) > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file1"]: Invalid argument > /mnt/scratch/test-420/file1: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > 0: [0..255]: 128..383 0 (128..383) 256 100000 > 1: [256..1023]: hole 768 > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file2"]: Invalid argument > /mnt/scratch/test-420/file2: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > 0: [0..255]: 128..383 0 (128..383) 256 100000 > 1: [256..1023]: hole 768 So this is the extent list for file2 after the reflink. Note the hole at 128-512kB. The flags tell us the 128kB data extent is shared. There are no unwritten extents at all. > > > Seek holes and data in file2 > > > Whence Result > > > DATA 0 > > > -HOLE 131072 > > > -DATA 196608 > > > -HOLE 262144 > > > +HOLE 524288 indicates the file is completely full of data at this point. Based on the extent list, and looking at the current iomap_seek_hole/data() implementation, this looks wrong. Technically speaking, however, it is valid because holes are allowed to be reported as data but not vice versa. That said, in this case there are no unwritten extents so iomap_seek_hole/data should be reporting the exact on-disk extent mapping and not even be looking at the page cache contents. The page cache is only only for unwritten extents, and there are none of them so page cache footprint should not change this result. > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file3"]: Invalid argument > /mnt/scratch/test-420/file3: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > 0: [0..1023]: 512..1535 0 (512..1535) 1024 > sync filesystem > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file1"]: Invalid argument > /mnt/scratch/test-420/file1: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > 0: [0..127]: 128..255 0 (128..255) 128 > 1: [128..255]: 256..383 0 (256..383) 128 100000 > 2: [256..1023]: hole 768 > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file2"]: Invalid argument > /mnt/scratch/test-420/file2: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > 0: [0..127]: 1536..1663 0 (1536..1663) 128 > 1: [128..255]: 256..383 0 (256..383) 128 100000 > 2: [256..383]: hole 128 > 3: [384..511]: 1920..2047 0 (1920..2047) 128 > 4: [512..1023]: hole 512 And the extent list after we've overwritten the first 64kB and another 64kB write at 192kB. Note that the 64kB hole at 128kB is still there. > > > @@ -13,9 +13,7 @@ > > > Seek holes and data in file2 > > > Whence Result > > > DATA 0 > > > -HOLE 131072 > > > -DATA 196608 > > > -HOLE 262144 > > > +HOLE 524288 And this still looks wrong. Again, no unwritten extents, so we should just be reporting the on-disk extent layout here. > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file3"]: Invalid argument > /mnt/scratch/test-420/file3: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > 0: [0..1023]: 512..1535 0 (512..1535) 1024 > Remount > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file1"]: Invalid argument > /mnt/scratch/test-420/file1: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > 0: [0..127]: 128..255 0 (128..255) 128 > 1: [128..255]: 256..383 0 (256..383) 128 100000 > 2: [256..1023]: hole 768 > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file2"]: Invalid argument > /mnt/scratch/test-420/file2: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > 0: [0..127]: 1536..1663 0 (1536..1663) 128 > 1: [128..255]: 256..383 0 (256..383) 128 100000 > 2: [256..383]: hole 128 > 3: [384..511]: 1920..2047 0 (1920..2047) 128 > 4: [512..1023]: hole 512 This is after mount/unmount, where there is now no page cache over the file. This reports the same layout as bmap does (i.e. matches the golden output) and is obviously correct. This smells of a bug in the large folio patchset as the on-disk extent layouts are correct and unchanged. The question now is what if the large folio patchset doing to iomap_seek_hole/data that makes it behave differently to the current code? Cheers, Dave. -- Dave Chinner david@fromorbit.com ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [mm/readahead] a0b99df1aa: xfstests.xfs.421.fail 2022-02-21 21:43 ` Dave Chinner @ 2022-02-23 19:59 ` Matthew Wilcox 2022-02-23 20:19 ` Matthew Wilcox 0 siblings, 1 reply; 6+ messages in thread From: Matthew Wilcox @ 2022-02-23 19:59 UTC (permalink / raw) To: Dave Chinner Cc: kernel test robot, lkp, lkp, LKML, Darrick J. Wong, linux-xfs, Christoph Hellwig On Tue, Feb 22, 2022 at 08:43:55AM +1100, Dave Chinner wrote: > On Mon, Feb 21, 2022 at 09:10:20PM +0000, Matthew Wilcox wrote: > > On Tue, Feb 22, 2022 at 07:55:29AM +1100, Dave Chinner wrote: > > > On Mon, Feb 21, 2022 at 01:56:55PM +0000, Matthew Wilcox wrote: > > > > On Mon, Feb 21, 2022 at 04:02:18PM +0800, kernel test robot wrote: > > > > > commit: a0b99df1aa37d714eb80be5fb54efd56c88a3336 ("mm/readahead: Add large folio readahead") > > > > > > > > > xfs/420 - output mismatch (see /lkp/benchmarks/xfstests/results//xfs/420.out.bad) > > > > > --- tests/xfs/420.out 2022-02-17 11:55:00.000000000 +0000 > > > > > +++ /lkp/benchmarks/xfstests/results//xfs/420.out.bad 2022-02-20 20:34:22.430378506 +0000 > > > > > @@ -13,9 +13,7 @@ > > > > > Seek holes and data in file2 > > > > > Whence Result > > > > > DATA 0 > > > > > -HOLE 131072 > > > > > -DATA 196608 > > > > > -HOLE 262144 > > > > > +HOLE 524288 > > > > > > > > Confirm this test now fails. I don't think it's actually a bug, > > > > though. I think the test is now using larger pages to cache the > > > > file, and it fails to report that there's a hole in the file. > > > > Maybe there actually isn't a hole in the file any more; using > > > > larger pages to cache the file means we'll now write more data > > > > than we used to. > > > > > > > > Adding XFS people for their thoughts. > > > > > > > > Complete output: > > > > > > > > $ diff -u ../ktest/tests/xfstests/tests/xfs/420.out ktest-out/xfstests/xfs/420.out.bad > > > > --- ../ktest/tests/xfstests/tests/xfs/420.out 2021-07-05 15:49:45.539887305 -0400 > > > > +++ ktest-out/xfstests/xfs/420.out.bad 2022-02-21 08:14:40.000000000 -0500 > > > > @@ -13,9 +13,7 @@ > > > > Seek holes and data in file2 > > > > Whence Result > > > > DATA 0 > > > > -HOLE 131072 > > > > -DATA 196608 > > > > -HOLE 262144 > > > > +HOLE 524288 > > > > Compare files > > > > c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 > > > > 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 > > > > @@ -28,9 +26,7 @@ > > > > Seek holes and data in file2 > > > > Whence Result > > > > DATA 0 > > > > -HOLE 131072 > > > > -DATA 196608 > > > > -HOLE 262144 > > > > +HOLE 524288 > > > > Compare files > > > > c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 > > > > 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 > > > > > > > > So the file checksums are right, which means I didn't break the COW > > > > functionality. But we're no longer reporting a hole at 128k. > > > > > > Can you post the contents of the 420.full output file so we can see > > > what the output of the various commands that are run are? e.g. > > > things like cowextsize that is configured, etc? > > > > Sure! It's short, so I've included it inline. > > Ok, I'll cut this up so it makes sense... > > > > > > > meta-data=/dev/sdc isize=512 agcount=4, agsize=3670016 blks > > = sectsz=512 attr=2, projid32bit=1 > > = crc=1 finobt=1, sparse=1, rmapbt=1 > > = reflink=1 bigtime=0 > > data = bsize=1024 blocks=14680064, imaxpct=25 > > = sunit=0 swidth=0 blks > > naming =version 2 bsize=4096 ascii-ci=0, ftype=1 > > log =internal log bsize=1024 blocks=10240, version=2 > > = sectsz=512 sunit=0 blks, lazy-count=1 > > realtime =none extsz=4096 blocks=0, rtextents=0 > > Discarding blocks...Done. > > [0] /mnt/scratch/test-420 > > [524288] /mnt/scratch/test-420 > > wrote 131072/131072 bytes at offset 0 > > 128 KiB, 128 ops; 0.0000 sec (1.327 GiB/sec and 1391304.3478 ops/sec) > > wrote 524288/524288 bytes at offset 0 > > 512 KiB, 512 ops; 0.0003 sec (1.341 GiB/sec and 1406593.4066 ops/sec) > > wrote 131072/131072 bytes at offset 0 > > 128 KiB, 128 ops; 0.0000 sec (1.822 GiB/sec and 1910447.7612 ops/sec) > > CoW the shared part then write into the empty part > > [524288] /mnt/scratch/test-420/file1 > > [524288] /mnt/scratch/test-420/file2 > > wrote 65536/65536 bytes at offset 0 > > 64 KiB, 64 ops; 0.0001 sec (416.667 MiB/sec and 426666.6667 ops/sec) > > wrote 65536/65536 bytes at offset 196608 > > 64 KiB, 64 ops; 0.0000 sec (1.695 GiB/sec and 1777777.7778 ops/sec) > > wrote 65536/65536 bytes at offset 0 > > 64 KiB, 64 ops; 0.0000 sec (1.387 GiB/sec and 1454545.4545 ops/sec) > > wrote 65536/65536 bytes at offset 196608 > > 64 KiB, 64 ops; 0.0000 sec (1.526 GiB/sec and 1600000.0000 ops/sec) > > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file1"]: Invalid argument > > /mnt/scratch/test-420/file1: > > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > > 0: [0..255]: 128..383 0 (128..383) 256 100000 > > 1: [256..1023]: hole 768 > > xfs_io: xfsctl(XFS_IOC_GETBMAPX) iflags=0x28 ["/mnt/scratch/test-420/file2"]: Invalid argument > > /mnt/scratch/test-420/file2: > > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > > 0: [0..255]: 128..383 0 (128..383) 256 100000 > > 1: [256..1023]: hole 768 > > So this is the extent list for file2 after the reflink. Note the > hole at 128-512kB. The flags tell us the 128kB data extent is > shared. There are no unwritten extents at all. My debugging indicates otherwise: +++ b/fs/iomap/seek.c @@ -15,6 +15,7 @@ static loff_t iomap_seek_hole_iter(const struct iomap_iter *it er, { loff_t length = iomap_length(iter); +printk("%s %ld %d:%lld,%lld\n", __func__, iter->inode->i_ino, iter->iomap.type, iter->iomap.length); switch (iter->iomap.type) { case IOMAP_UNWRITTEN: *hole_pos = mapping_seek_hole_data(iter->inode->i_mapping, @@ -61,6 +62,7 @@ static loff_t iomap_seek_data_iter(const struct iomap_iter *iter, { loff_t length = iomap_length(iter); +printk("%s %ld %d:%lld,%lld\n", __func__, iter->inode->i_ino, iter->iomap.type, iter->iomap.length); switch (iter->iomap.type) { case IOMAP_HOLE: return length; gives me output: 00016 iomap_seek_hole_iter 68 2:131072,-131387284454392 00016 iomap_seek_hole_iter 68 0:393216,-131387284454392 00016 iomap_seek_data_iter 68 2:131072,-131387284454392 00016 iomap_seek_hole_iter 68 2:131072,-131387284454392 00016 iomap_seek_hole_iter 68 0:393216,-131387284454392 00016 iomap_seek_data_iter 68 0:393216,-131387284454392 00016 iomap_seek_hole_iter 69 2:131072,-131387284455352 00016 iomap_seek_hole_iter 69 3:393216,4503599627239424 00016 iomap_seek_data_iter 69 2:131072,-131387284455352 00016 iomap_seek_hole_iter 69 2:131072,-131387284455352 00016 iomap_seek_hole_iter 69 3:393216,4503599627239424 This is after the first call to drop_caches, so in userspace, we're doing: echo 1 > /proc/sys/vm/drop_caches echo "CoW the shared part then write into the empty part" | tee -a $seqres.full $XFS_IO_PROG -c "cowextsize" $testdir/file1 >> $seqres.full grep 'order=[^0]' /sys/kernel/debug/tracing/trace $XFS_IO_PROG -c "cowextsize" $testdir/file2 >> $seqres.full grep 'order=[^0]' /sys/kernel/debug/tracing/trace $XFS_IO_PROG -c "pwrite -S 0x63 0 $blksz" $testdir/file2 >> $seqres.full grep 'order=[^0]' /sys/kernel/debug/tracing/trace $XFS_IO_PROG -c "pwrite -S 0x63 $((blksz * 3)) $blksz" $testdir/file2 >> $seqres.full grep 'order=[^0]' /sys/kernel/debug/tracing/trace The calls to grep were added by me, and should show any order>0 pages added to the page cache. There are none, which seems like it would exonerate large folios. Of course, it must be this commit, so there must be large pages. Debugging continues ... ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [mm/readahead] a0b99df1aa: xfstests.xfs.421.fail 2022-02-23 19:59 ` Matthew Wilcox @ 2022-02-23 20:19 ` Matthew Wilcox 0 siblings, 0 replies; 6+ messages in thread From: Matthew Wilcox @ 2022-02-23 20:19 UTC (permalink / raw) To: Dave Chinner Cc: kernel test robot, lkp, lkp, LKML, Darrick J. Wong, linux-xfs, Christoph Hellwig On Wed, Feb 23, 2022 at 07:59:39PM +0000, Matthew Wilcox wrote: > > > /mnt/scratch/test-420/file2: > > > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL > > > 0: [0..255]: 128..383 0 (128..383) 256 100000 > > > 1: [256..1023]: hole 768 > > > > So this is the extent list for file2 after the reflink. Note the > > hole at 128-512kB. The flags tell us the 128kB data extent is > > shared. There are no unwritten extents at all. > > My debugging indicates otherwise: > > +++ b/fs/iomap/seek.c > @@ -15,6 +15,7 @@ static loff_t iomap_seek_hole_iter(const struct iomap_iter *it > er, > { > loff_t length = iomap_length(iter); > > +printk("%s %ld %d:%lld,%lld\n", __func__, iter->inode->i_ino, iter->iomap.type, iter->iomap.length); > switch (iter->iomap.type) { > case IOMAP_UNWRITTEN: > *hole_pos = mapping_seek_hole_data(iter->inode->i_mapping, > @@ -61,6 +62,7 @@ static loff_t iomap_seek_data_iter(const struct iomap_iter *iter, > { > loff_t length = iomap_length(iter); > > +printk("%s %ld %d:%lld,%lld\n", __func__, iter->inode->i_ino, iter->iomap.type, iter->iomap.length); > switch (iter->iomap.type) { > case IOMAP_HOLE: > return length; > > gives me output: > > 00016 iomap_seek_hole_iter 68 2:131072,-131387284454392 > 00016 iomap_seek_hole_iter 68 0:393216,-131387284454392 > 00016 iomap_seek_data_iter 68 2:131072,-131387284454392 > 00016 iomap_seek_hole_iter 68 2:131072,-131387284454392 > 00016 iomap_seek_hole_iter 68 0:393216,-131387284454392 > 00016 iomap_seek_data_iter 68 0:393216,-131387284454392 > 00016 iomap_seek_hole_iter 69 2:131072,-131387284455352 > 00016 iomap_seek_hole_iter 69 3:393216,4503599627239424 > 00016 iomap_seek_data_iter 69 2:131072,-131387284455352 > 00016 iomap_seek_hole_iter 69 2:131072,-131387284455352 > 00016 iomap_seek_hole_iter 69 3:393216,4503599627239424 I forgot to print 'offset' first, so that's showing (type:len,garbage) With that fixed, and a call to dump_page() in folio_seek_hole_data(), I see: 00016 iomap_seek_hole_iter 69 3:131072,65536 00016 page:00000000f7f02915 refcount:18 mapcount:0 mapping:000000008692207c index:0x20 pfn:0x108750 00016 head:00000000f7f02915 order:4 compound_mapcount:0 compound_pincount:0 00016 aops:0xffffffff81c32a00 ino:45 dentry name:"file2" 00016 flags: 0x8000000000012014(uptodate|lru|private|head|zone=2) 00016 raw: 8000000000012014 ffffea000421e008 ffffea000421d008 ffff888103947520 00016 raw: 0000000000000020 ffff8881051cd2a0 00000012ffffffff 0000000000000000 00016 page dumped because: folio_seek_hole_data (inode 69 decimal is 45 hex) So I think this explains the output? an order-4 page is 64kB, so it'll report the entirety of 128kB-192kB as data. ^ permalink raw reply [flat|nested] 6+ messages in thread
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2022-02-21 13:56 ` [mm/readahead] a0b99df1aa: xfstests.xfs.421.fail Matthew Wilcox
2022-02-21 20:55 ` Dave Chinner
2022-02-21 21:10 ` Matthew Wilcox
2022-02-21 21:43 ` Dave Chinner
2022-02-23 19:59 ` Matthew Wilcox
2022-02-23 20:19 ` Matthew Wilcox
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