kernel test robot writes: > Greeting, > > FYI, we noticed the following commit (built with gcc-9): > > commit: 94a4dd06a6bbf3978b0bb1dddc2d8ec4e5bcad26 ("[PATCH v9] vfs: fix copy_file_range regression in cross-fs copies") > url: https://github.com/0day-ci/linux/commits/Luis-Henriques/vfs-fix-copy_file_range-regression-in-cross-fs-copies/20210510-170804 > base: https://git.kernel.org/cgit/linux/kernel/git/viro/vfs.git for-next > > in testcase: xfstests > version: xfstests-x86_64-73c0871-1_20210401 > with following parameters: > > disk: 4HDD > fs: xfs > test: generic-group-13 > ucode: 0x21 > > test-description: xfstests is a regression test suite for xfs and other files ystems. > test-url: git://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git > > > on test machine: 4 threads 1 sockets Intel(R) Core(TM) i3-3220 CPU @ 3.30GHz with 8G memory > > caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): > > > > > If you fix the issue, kindly add following tag > Reported-by: kernel test robot > > 2021-05-11 11:28:23 export TEST_DIR=/fs/sda1 > 2021-05-11 11:28:23 export TEST_DEV=/dev/sda1 > 2021-05-11 11:28:23 export FSTYP=xfs > 2021-05-11 11:28:23 export SCRATCH_MNT=/fs/scratch > 2021-05-11 11:28:23 mkdir /fs/scratch -p > 2021-05-11 11:28:23 export SCRATCH_DEV=/dev/sda4 > 2021-05-11 11:28:23 export SCRATCH_LOGDEV=/dev/sda2 > 2021-05-11 11:28:23 sed "s:^:generic/:" //lkp/benchmarks/xfstests/tests/generic-group-13 > 2021-05-11 11:28:23 ./check generic/260 generic/261 generic/262 generic/263 generic/264 generic/265 generic/266 generic/267 generic/268 generic/269 generic/270 generic/271 generic/272 generic/273 generic/274 generic/275 generic/276 generic/277 generic/278 generic/279 > FSTYP -- xfs (debug) > PLATFORM -- Linux/x86_64 lkp-ivb-d02 5.12.0-rc6-00061-g94a4dd06a6bb #1 SMP Tue May 11 00:58:17 CST 2021 > MKFS_OPTIONS -- -f -bsize=4096 /dev/sda4 > MOUNT_OPTIONS -- /dev/sda4 /fs/scratch > > generic/260 [not run] FITRIM not supported on /fs/scratch > generic/261 [not run] Reflink not supported by scratch filesystem type: xfs > generic/262 [not run] Reflink not supported by scratch filesystem type: xfs > generic/263 [failed, exit status 1]- output mismatch (see /lkp/benchmarks/xfstests/results//generic/263.out.bad) > --- tests/generic/263.out 2021-04-01 03:07:08.000000000 +0000 > +++ /lkp/benchmarks/xfstests/results//generic/263.out.bad 2021-05-11 11:28:29.773460096 +0000 > @@ -1,3 +1,32 @@ > QA output created by 263 > fsx -N 10000 -o 8192 -l 500000 -r PSIZE -t BSIZE -w BSIZE -Z > -fsx -N 10000 -o 128000 -l 500000 -r PSIZE -t BSIZE -w BSIZE -Z > +Seed set to 1 > +main: filesystem does not support clone range, disabling! > +main: filesystem does not support dedupe range, disabling! > +skipping zero size read > ... > (Run 'diff -u /lkp/benchmarks/xfstests/tests/generic/263.out /lkp/benchmarks/xfstests/results//generic/263.out.bad' to see the entire diff) > generic/264 [not run] Reflink not supported by scratch filesystem type: xfs > generic/265 [not run] Reflink not supported by scratch filesystem type: xfs > generic/266 [not run] Reflink not supported by scratch filesystem type: xfs > generic/267 [not run] Reflink not supported by scratch filesystem type: xfs > generic/268 [not run] Reflink not supported by scratch filesystem type: xfs > generic/269 48s > generic/270 61s > generic/271 [not run] Reflink not supported by scratch filesystem type: xfs > generic/272 [not run] Reflink not supported by scratch filesystem type: xfs > generic/273 17s > generic/274 14s > generic/275 11s > generic/276 [not run] Reflink not supported by scratch filesystem type: xfs > generic/277 3s > generic/278 [not run] Reflink not supported by scratch filesystem type: xfs > generic/279 [not run] Reflink not supported by scratch filesystem type: xfs > Ran: generic/260 generic/261 generic/262 generic/263 generic/264 generic/265 generic/266 generic/267 generic/268 generic/269 generic/270 generic/271 generic/272 generic/273 generic/274 generic/275 generic/276 generic/277 generic/278 generic/279 > Not run: generic/260 generic/261 generic/262 generic/264 generic/265 generic/266 generic/267 generic/268 generic/271 generic/272 generic/276 generic/278 generic/279 > Failures: generic/263 > Failed 1 of 20 tests OK, I see what's going on. There are 2 issues: one with patch and another one with the test itself. The CFR syscall should have been disabled in this test but it isn't because the test tries to copy 1 byte from a zero-sized file: int test_copy_range(void) { loff_t o1 = 0, o2 = 1; if (syscall(__NR_copy_file_range, fd, &o1, fd, &o2, 1, 0) == -1 && (errno == ENOSYS || errno == EOPNOTSUPP || errno == ENOTTY)) { if (!quiet) fprintf(stderr, "main: filesystem does not support " "copy range, disabling!\n"); return 0; } return 1; } The syscall is doing an early '0' return because the file size is < len. Fixing the kernel should probably be as easy as removing the short-circuiting check in vfs_copy_file_range(): if (len == 0) return 0; This will force the filesystems code to handle '0' size copies but will also make sure -EOPNOTSUPP is returned in this case. Alternatively, we could have something like: if (len == 0) { if (file_out->f_op->copy_file_range) return 0; else return -EOPNOTSUPP; } What do you guys think is the right thing to do? Additionally, the test should also be fixed with something as the patch bellow. By making sure we have 1 byte to copy we also ensure the syscall will return -EOPNOTSUPP, even with the current version of the patch. Cheers, -- Luis diff --git a/ltp/fsx.c b/ltp/fsx.c index cd0bae55aeb8..97db594ae142 100644 --- a/ltp/fsx.c +++ b/ltp/fsx.c @@ -1596,6 +1596,10 @@ int test_copy_range(void) { loff_t o1 = 0, o2 = 1; + int ret = 1; + + /* Make sure we have 1 byte to copy */ + ftruncate(fd, 1); if (syscall(__NR_copy_file_range, fd, &o1, fd, &o2, 1, 0) == -1 && (errno == ENOSYS || errno == EOPNOTSUPP || errno == ENOTTY)) { @@ -1603,10 +1607,13 @@ test_copy_range(void) fprintf(stderr, "main: filesystem does not support " "copy range, disabling!\n"); - return 0; + ret = 0; } - return 1; + /* Restore file size */ + ftruncate(fd, 0); + + return ret; } void